| 1. |
- Beal, Jacob, et al.
(författare)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- An, Junghwa, et al.
(författare)
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Permanent Genetic Resources added to Molecular Ecology Resources Database 1 October 2009-30 November 2009
- 2010
-
Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 10:2, s. 404-408
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Tidskriftsartikel (refereegranskat)abstract
- This article documents the addition of 411 microsatellite marker loci and 15 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Acanthopagrus schlegeli, Anopheles lesteri, Aspergillus clavatus, Aspergillus flavus, Aspergillus fumigatus, Aspergillus oryzae, Aspergillus terreus, Branchiostoma japonicum, Branchiostoma belcheri, Colias behrii, Coryphopterus personatus, Cynogolssus semilaevis, Cynoglossus semilaevis, Dendrobium officinale, Dendrobium officinale, Dysoxylum malabaricum, Metrioptera roeselii, Myrmeciza exsul, Ochotona thibetana, Neosartorya fischeri, Nothofagus pumilio, Onychodactylus fischeri, Phoenicopterus roseus, Salvia officinalis L., Scylla paramamosain, Silene latifo, Sula sula, and Vulpes vulpes. These loci were cross-tested on the following species: Aspergillus giganteus, Colias pelidne, Colias interior, Colias meadii, Colias eurytheme, Coryphopterus lipernes, Coryphopterus glaucofrenum, Coryphopterus eidolon, Gnatholepis thompsoni, Elacatinus evelynae, Dendrobium loddigesii Dendrobium devonianum, Dysoxylum binectariferum, Nothofagus antarctica, Nothofagus dombeyii, Nothofagus nervosa, Nothofagus obliqua, Sula nebouxii, and Sula variegata. This article also documents the addition of 39 sequencing primer pairs and 15 allele specific primers or probes for Paralithodes camtschaticus.
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| 3. |
- Jin, Ying-Hui, et al.
(författare)
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Chemoprophylaxis, diagnosis, treatments, and discharge management of COVID-19 : An evidence-based clinical practice guideline (updated version)
- 2020
-
Ingår i: Military Medical Research. - : Springer Science and Business Media LLC. - 2054-9369. ; 7:1
-
Tidskriftsartikel (refereegranskat)abstract
- The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a rapidly spreading illness, coronavirus disease 2019 (COVID-19), affecting more than seventeen million people around the world. Diagnosis and treatment guidelines for clinicians caring for patients are needed. In the early stage, we have issued "A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus (2019-nCoV) infected pneumonia (standard version)"; now there are many direct evidences emerged and may change some of previous recommendations and it is ripe for develop an evidence-based guideline. We formed a working group of clinical experts and methodologists. The steering group members proposed 29 questions that are relevant to the management of COVID-19 covering the following areas: chemoprophylaxis, diagnosis, treatments, and discharge management. We searched the literature for direct evidence on the management of COVID-19, and assessed its certainty generated recommendations using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Recommendations were either strong or weak, or in the form of ungraded consensus-based statement. Finally, we issued 34 statements. Among them, 6 were strong recommendations for, 14 were weak recommendations for, 3 were weak recommendations against and 11 were ungraded consensus-based statement. They covered topics of chemoprophylaxis (including agents and Traditional Chinese Medicine (TCM) agents), diagnosis (including clinical manifestations, reverse transcription-polymerase chain reaction (RT-PCR), respiratory tract specimens, IgM and IgG antibody tests, chest computed tomography, chest x-ray, and CT features of asymptomatic infections), treatments (including lopinavir-ritonavir, umifenovir, favipiravir, interferon, remdesivir, combination of antiviral drugs, hydroxychloroquine/chloroquine, interleukin-6 inhibitors, interleukin-1 inhibitors, glucocorticoid, qingfei paidu decoction, lianhua qingwen granules/capsules, convalescent plasma, lung transplantation, invasive or noninvasive ventilation, and extracorporeal membrane oxygenation (ECMO)), and discharge management (including discharge criteria and management plan in patients whose RT-PCR retesting shows SARS-CoV-2 positive after discharge). We also created two figures of these recommendations for the implementation purpose. We hope these recommendations can help support healthcare workers caring for COVID-19 patients.
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| 4. |
- Canesin, Giacomo, et al.
(författare)
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Scavenging of Labile Heme by Hemopexin Is a Key Checkpoint in Cancer Growth and Metastases
- 2020
-
Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 32:12
-
Tidskriftsartikel (refereegranskat)abstract
- Canesin et al. describe a role and mechanism for labile heme as a key player in regulating gene expression to promote carcinogenesis via binding to G-quadruplex in the c-MYC promoter. Hemopexin, a heme scavenger, may be used as a strategy to block progression of cancer.
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| 5. |
- Cao, Da-fu, et al.
(författare)
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Evaluation of prestress losses in prestressed concrete specimens subjected to freeze–thaw cycles
- 2016
-
Ingår i: Structure and Infrastructure Engineering. - Abington, UK : Taylor & Francis. - 1573-2479 .- 1744-8980. ; 12:2, s. 159-170
-
Tidskriftsartikel (refereegranskat)abstract
- Prestressed concrete structures are considered to be reliable and durable. However, their long-term performance when subjected to frost attack is still unclear. In this work, experiments were carried out to evaluate the prestress losses in post-tensioned prestressed concrete specimens subjected to freeze–thaw cycles (FTCs). Two cases were considered: in one case, a series of specimens were prepared and tested in a freeze–thaw chamber; in the second case, the same series of specimens were tested in an indoor environment (outside the chamber). The difference between the prestress losses of the specimens inside the freeze–thaw chamber and those outside the chamber equalled the prestress losses due to FTCs. When using mathematical models to predict the prestress losses due to the FTCs, it was found that they were relatively small when the concrete was slightly damaged. However, they increased rapidly when the FTCs were repeated. The eccentricity of the prestress wires led to larger prestress losses when subjected to FTCs. Moreover, the same cross section and eccentricity resulted in similar prestress losses due to the FTCs, and the relatively high-strength concrete could withstand more FTCs.
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| 6. |
- Cardoso-Moreira, Margarida, et al.
(författare)
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Gene expression across mammalian organ development
- 2019
-
Ingår i: Nature. - : NATURE PUBLISHING GROUP. - 0028-0836 .- 1476-4687. ; 571:7766, s. 505-
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of gene expression in mammalian organ development remains largely uncharacterized. Here we report the transcriptomes of seven organs (cerebrum, cerebellum, heart, kidney, liver, ovary and testis) across developmental time points from early organogenesis to adulthood for human, rhesus macaque, mouse, rat, rabbit, opossum and chicken. Comparisons of gene expression patterns identified correspondences of developmental stages across species, and differences in the timing of key events during the development of the gonads. We found that the breadth of gene expression and the extent of purifying selection gradually decrease during development, whereas the amount of positive selection and expression of new genes increase. We identified differences in the temporal trajectories of expression of individual genes across species, with brain tissues showing the smallest percentage of trajectory changes, and the liver and testis showing the largest. Our work provides a resource of developmental transcriptomes of seven organs across seven species, and comparative analyses that characterize the development and evolution of mammalian organs.
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| 7. |
- Feng, Tongbao, et al.
(författare)
-
miR-124 downregulation leads to breast cancer progression via LncRNA-MALAT1 regulation and CDK4/E2F1 signal activation.
- 2016
-
Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:13, s. 16205-16216
-
Tidskriftsartikel (refereegranskat)abstract
- The long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been recently shown to be dysregulated in several cancers. However, the mechanisms underlying the role of MALAT1 in breast cancer remain unclear. Herein, we showed that MALAT1 was aberrantly increased in breast cancer tissues and cells. MALAT1-siRNA inhibited breast cancer cell proliferation and cell cycle progression in vitro and in vivo. Furthermore, MALAT1 acted as an endogenous potent regulator by directly binding to miR-124 and down-regulating miR-124 expression. In addition, MALAT1 reversed the inhibitory effect of miR-124 on breast cancer proliferation and was involved in the cyclin-dependent kinase 4 (CDK4) expression. Taken together, our data highlight the pivotal role of MALAT1 in breast cancer tumorigenesis. Moreover, the present study elucidated the MALAT1-miR-124-CDK4/E2F1 signaling pathway in breast cancer, which might provide a new approach for tackling breast cancer.
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| 8. |
- Gao, Hong, et al.
(författare)
-
The landscape of tolerated genetic variation in humans and primates
- 2023
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 380:6648
-
Tidskriftsartikel (refereegranskat)abstract
- Personalized genome sequencing has revealed millions of genetic differences between individuals, but our understanding of their clinical relevance remains largely incomplete. To systematically decipher the effects of human genetic variants, we obtained whole-genome sequencing data for 809 individuals from 233 primate species and identified 4.3 million common protein-altering variants with orthologs in humans. We show that these variants can be inferred to have nondeleterious effects in humans based on their presence at high allele frequencies in other primate populations. We use this resource to classify 6% of all possible human protein-altering variants as likely benign and impute the pathogenicity of the remaining 94% of variants with deep learning, achieving state-of-the-art accuracy for diagnosing pathogenic variants in patients with genetic diseases.
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| 9. |
- Guangming, Shao, et al.
(författare)
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A novel cooperative platform design for coupled USV-UAV systems
- 2019
-
Ingår i: IEEE Transactions on Industrial Informatics. - : IEEE. - 1551-3203 .- 1941-0050. ; 15:9, s. 4913-4922
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a novel cooperative USV-UAV platform to form a powerful combination, which offers foundations for collaborative task executed by the coupled USV-UAV systems. Adjustable buoys and unique carrier deck for the USV are designed to guarantee landing safety and transportation of UAV. The deck of USV is equipped with a series of sensors, and a multi-ultrasonic joint dynamic positioning algorithm is introduced for resolving the positioning problem of the coupled USV-UAV systems. To fulfill effective guidance for the landing operation of UAV, we design a hierarchical landing guide point generation algorithm to obtain a sequence of guide points. By employing the above sequential guide points, high quality paths are planned for the UAV. Cooperative dynamic positioning process of the USV-UAV systems is elucidated, and then UAV can achieve landing on the deck of USV steadily. Our cooperative USV-UAV platform is validated by simulation and water experiments.
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| 10. |
- Hassanein, M. F., et al.
(författare)
-
Small-scale laterally-unrestrained corrugated web girders: (II) Parametric studies and LTB design
- 2022
-
Ingår i: Thin-Walled Structures. - : Elsevier BV. - 0263-8231. ; 180
-
Tidskriftsartikel (refereegranskat)abstract
- As shown in the companion paper, innovative tests of corrugated web girders (CWGs) were performed followed by validation of the finite element (FE) model. Accordingly, this paper continues investigating the lateral–torsional buckling of small-scale corrugated web girders through parametric studies. This is to expand the available data required to unveil their behaviour and strength. The layout of the tested girders is considered herein, where the webs of small corrugation dimensions are under pure bending moment with symmetrical boundary conditions. This study deals with the linear and nonlinear buckling analyses of the lateral–torsional buckling (LTB) of CWGs using ABAQUS software. Accordingly, 108 models are conducted, considering the effects of the girder length, web overall dimensions, corrugation dimensions, flange dimensions and different steel grades. The results show that increasing the girder length decreases consequently the ultimate flexural strength and stiffness of CWGs. With regard to the web overall dimensions, increasing the web depth is found to have a significant effect on the strength of CWGs in contrast to the effect of the web thickness value, which has insignificant effect on strength. Furthermore, the results revealed that increasing the flange dimensions increases subsequently the strengths of CWGs. In addition, it is noted that the lower the steel grade, the more effectively the material is used especially for girders failing elastically. Additionally, the critical and design LTB strengths of small-scale CWGs with small corrugation dimensions are evaluated. The comparisons show that the critical LTB stress requires modifications to accord well with FE results. Furthermore, comparisons of the ultimate FE strengths with those of Lindner's equation (1990), EC3 (2004) and AISC (2010) are provided. The comparisons exhibit that the predictions of Lindner's equation (1990) are suitable, while the predictions of EC3 (2004) and AISC (2010) are highly conservative. Therefore, modifications are made for EC3 (2004) and AISC (2010) design models to provide more appropriate design strengths for CWGs with small corrugation dimensions for use in buildings.
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| 11. |
- Kristan, Matej, et al.
(författare)
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The Ninth Visual Object Tracking VOT2021 Challenge Results
- 2021
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Ingår i: 2021 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW 2021). - : IEEE COMPUTER SOC. - 9781665401913 ; , s. 2711-2738
-
Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2021 is the ninth annual tracker benchmarking activity organized by the VOT initiative. Results of 71 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in recent years. The VOT2021 challenge was composed of four sub-challenges focusing on different tracking domains: (i) VOT-ST2021 challenge focused on short-term tracking in RGB, (ii) VOT-RT2021 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2021 focused on long-term tracking, namely coping with target disappearance and reappearance and (iv) VOT-RGBD2021 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2021 dataset was refreshed, while VOT-RGBD2021 introduces a training dataset and sequestered dataset for winner identification. The source code for most of the trackers, the datasets, the evaluation kit and the results along with the source code for most trackers are publicly available at the challenge website(1).
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| 12. |
- Kuderna, Lukas F. K., et al.
(författare)
-
A global catalog of whole-genome diversity from 233 primate species
- 2023
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 380:6648, s. 906-913
-
Tidskriftsartikel (refereegranskat)abstract
- The rich diversity of morphology and behavior displayed across primate species provides an informative context in which to study the impact of genomic diversity on fundamental biological processes. Analysis of that diversity provides insight into long-standing questions in evolutionary and conservation biology and is urgent given severe threats these species are facing. Here, we present high-coverage wholegenome data from 233 primate species representing 86% of genera and all 16 families. This dataset was used, together with fossil calibration, to create a nuclear DNA phylogeny and to reassess evolutionary divergence times among primate clades. We found within-species genetic diversity across families and geographic regions to be associated with climate and sociality, but not with extinction risk. Furthermore, mutation rates differ across species, potentially influenced by effective population sizes. Lastly, we identified extensive recurrence of missense mutations previously thought to be human specific. This study will open a wide range of research avenues for future primate genomic research.
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| 13. |
- Kuderna, Lukas F. K., et al.
(författare)
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Identification of constrained sequence elements across 239 primate genomes
- 2024
-
Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 625:7996, s. 735-742
-
Tidskriftsartikel (refereegranskat)abstract
- Noncoding DNA is central to our understanding of human gene regulation and complex diseases1,2, and measuring the evolutionary sequence constraint can establish the functional relevance of putative regulatory elements in the human genome3,4,5,6,7,8,9. Identifying the genomic elements that have become constrained specifically in primates has been hampered by the faster evolution of noncoding DNA compared to protein-coding DNA10, the relatively short timescales separating primate species11, and the previously limited availability of whole-genome sequences12. Here we construct a whole-genome alignment of 239 species, representing nearly half of all extant species in the primate order. Using this resource, we identified human regulatory elements that are under selective constraint across primates and other mammals at a 5% false discovery rate. We detected 111,318 DNase I hypersensitivity sites and 267,410 transcription factor binding sites that are constrained specifically in primates but not across other placental mammals and validate their cis-regulatory effects on gene expression. These regulatory elements are enriched for human genetic variants that affect gene expression and complex traits and diseases. Our results highlight the important role of recent evolution in regulatory sequence elements differentiating primates, including humans, from other placental mammals.
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| 14. |
- Lan, Meng, et al.
(författare)
-
Highly redispersible CNT dough for better processiblity
- 2023
-
Ingår i: Journal of Materials Science & Technology. - : Elsevier BV. - 1005-0302. ; 152, s. 65-74
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon nanotubes (CNTs) have received considerable attention for their excellent thermal and electrical conductivity as well as scalable production. However, CNT dispersions are prone to settling and have a short shelf time, especially under high concentration, which significantly hinders their further processing and increases transportation costs. Here, we report a highly concentrated CNT dough enabled by ionic liquid crystal (ILC) as auxiliaries. Benefiting from the temperature-controlled physical transformation of the ILC, the CNTs of the powder state are successfully transferred to highly processable dough with excellent electrical conductivity, flame retardancy, and outstanding redispersibility even after 180 days of storage. In particular, the CNT dough exhibits excellent self-healing properties and good reshapable capability. Various bulk form CNT derived from the ILC armored CNT dough are realized by facile processing technique. Hybrid nanocomposite papers with ANF nanofiber exhibited excellent photothermal conversion and Joule heating properties. The redispersible CNT doughs presented here promise to revolutionize traditional CNT powder and dispersions as the primary raw material for building CNT-based architectures and facilitate the large-scale application of CNTs.
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| 15. |
- Li, Liang, et al.
(författare)
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A Large Catalog of Multiwavelength GRB Afterglows. I. Color Evolution and Its Physical Implication
- 2018
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Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics Publishing (IOPP). - 0067-0049 .- 1538-4365. ; 234:2
-
Tidskriftsartikel (refereegranskat)abstract
- The spectrum of gamma-ray burst (GRB) afterglows can be studied with color indices. Here, we present a large comprehensive catalog of 70 GRBs with multiwavelength optical transient data on which we perform a systematic study to find the temporal evolution of color indices. We categorize them into two samples based on how well the color indices are evaluated. The Golden sample includes 25 bursts mostly observed by GROND, and the Silver sample includes 45 bursts observed by other telescopes. For the Golden sample, we find that 96% of the color indices do not vary over time. However, the color indices do vary during short periods in most bursts. The observed variations are consistent with effects of (i) the cooling frequency crossing the studied energy bands in a wind medium (43%) and in a constant-density medium (30%), (ii) early dust extinction (12%), (iii) transition from reverse-shock to forward-shock emission (5%), or (iv) an emergent SN emission (10%). We also study the evolutionary properties of the mean color indices for different emission episodes. We find that 86% of the color indices in the 70 bursts show constancy between consecutive ones. The color index variations occur mainly during the late GRB-SN bump, the flare, and early reverse-shock emission components. We further perform a statistical analysis of various observational properties and model parameters (spectral index beta(CI)(o), electron spectral indices p(CI), etc.) using color indices. Overall, we conclude that similar to 90% of colors are constant in time and can be accounted for by the simplest external forward-shock model, while the varying color indices call for more detailed modeling.
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| 16. |
- Li, Xin, et al.
(författare)
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Intelligent fault diagnosis of bevel gearboxes using semi-supervised probability support matrix machine and infrared imaging
- 2023
-
Ingår i: Reliability Engineering & System Safety. - : Elsevier. - 0951-8320 .- 1879-0836. ; 230
-
Tidskriftsartikel (refereegranskat)abstract
- Fault diagnosis is of great significance to ensure the reliability and safety of complex bevel gearbox systems. Most existing intelligent fault diagnosis approaches of bevel gearboxes are designed with vibration monitoring. However, the collected vibration data are vulnerable to noise pollution and machinery operating conditions. Besides, traditional fault diagnosis models highly rely on numerous labeled samples, and neglect the high cost of label annotation in real-world applications. Therefore, a novel fault diagnosis approach based on semi-supervised probability support matrix machine (SPSMM) and infrared imaging is proposed for bevel gearboxes in this paper, which has the following properties. Firstly, SPSMM classifies 2D matrix data directly without vectorization, thus fully utilizing the spatial information in infrared images. Secondly, a probability output strategy is designed for SPSMM to calculate the posterior class probability estimation of matrix inputs, and consequently enhance the diagnostic accuracy and robustness of the model. Thirdly, a semi-supervised learning (SSL) framework is proposed for SPSMM to carry out sample transfer from the unlabeled sample pool to the labeled sample pool, which can effectively alleviate the problem of insufficient labeled samples. The superiority of the proposed diagnosis approach is demonstrated with an infrared imaging dataset of a bevel gearbox.
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| 17. |
- Liu, Jia Rong, et al.
(författare)
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Effects of second-order wave force on fatigue damage assessment of a tlp-type floating wind turbine
- 2020
-
Ingår i: Proceedings of the International Offshore and Polar Engineering Conference. - 1098-6189 .- 1555-1792. ; 2020-October, s. 415-422
-
Konferensbidrag (refereegranskat)abstract
- Resonant and transient responses of a tension leg platform (TLP)-type floating offshore wind turbine can be excited by high-frequency wave forces. This paper investigates the damaging effect of second-order wave forces on structural fatigue in the WindStar TLP system. Dynamic responses in the time domain are analyzed using the program FAST. To explore the mechanisms of different combinations of wind and wave loads inducing damage, five scenarios are considered: wind only, first-order wave only, second-order wave only, joint wind and first-order wave, and joint wind and second-order wave. The results show the dominant effect of second-order waves in tower structural fatigue damage. Additionally, wind and wave coupling becomes stronger under second-order wave loads.
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| 18. |
- Liu, Yong-feng, et al.
(författare)
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A turn-on ratiometric fluorescent nanoprobe based on AgInZnS and nitrogen-doped graphene quantum dots for Cd2+ detection in lake water
- 2022
-
Ingår i: Journal of Materials Science. - : Springer Nature. - 0022-2461 .- 1573-4803. ; 57:36, s. 17336-17346
-
Tidskriftsartikel (refereegranskat)abstract
- Excessive Cd2+ poses adverse influences on ecosystem and human beings, but its precise detection via a facile and environment-friendly method with resistance to interference is still a challenge. Here, a turn-on ratiometric fluorescent nanoprobe for Cd2+ detection is established using yellow-emission AgInZnS quantum dots (AIZS QDs) and blue-emission nitrogen-doped graphene quantum dots (NGQDs), which serve as a recognition unit and internal reference signal, respectively. Cd2+ could enhance the fluorescence of AIZS QDs due to the passivation of surface defects, while it has no significant effect on that of NGQDs. This nanoprobe has a large detection range from 0.5 to 100 µM and a limit of detection low to 28.6 nM. It shows strong anti-interference ability for Cd2+ even in lake water samples with recovery from 98 to 101% and low relative standard deviation of 1.01%, indicating its excellent effectuation to real-application world.
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| 19. |
- Liu, Yong-feng, et al.
(författare)
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Sulfur quantum dot as a fluorescent nanoprobe for Fe3+ ions : Uncovering of detection mechanism, high sensitivity, and large detection range
- 2023
-
Ingår i: Journal of Luminescence. - : Elsevier. - 0022-2313 .- 1872-7883. ; 257
-
Tidskriftsartikel (refereegranskat)abstract
- Sulfur quantum dots (SQDs), as a novel metal-free fluorescent material, are getting increasingly tremendous attention in metal ion detection, especially for Fe3+, due to the merits of antimicrobial potential, low toxicity, and exciting optoelectronic properties. However, sensing mechanism of SQD based fluorescent probe for Fe3+ is not clear yet, and high sensitivity and large detection range remain a challenge. Here, we report the synthesis of hydrophilic SQDs as a fluorescent nanoprobe for Fe3+ via a fluorescent turn-off mode. We systematically studied the quenching mechanism by ultraviolet–visible absorption spectra, steady-state and time-resolved photoluminescent spectra, and temperature-dependent quenching constants. Results unclearly evidenced the quenching behavior to both inner filter effect and static quenching. Furthermore, the nanoprobe presents a large detection range from 2.5 to 700 μM and a limit of detection low to 53.6 nM, both of which are the record performance to our knowledge. At last, it shows high selectivity toward Fe3+ and presents no ionic strength effect in the range of investigation, which enables surprising results for Fe3+ detection in deionized water with interference ion and real water samples.
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| 20. |
- Liu, Yong-feng, et al.
(författare)
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The influence of the capping ligands on the optoelectronic performance, morphology, and ion liberation of CsPbBr3 perovskite quantum dots
- 2023
-
Ingår i: Nano Reseach. - : Springer Nature. - 1998-0124 .- 1998-0000. ; 16:7, s. 10626-10633
-
Tidskriftsartikel (refereegranskat)abstract
- Perovskite quantum dots (PeQDs) endowed with capping ligands exhibit impressive optoelectronic properties and enable for cost-efficient solution processing and exciting application opportunities. We synthesize and characterize three different PeQDs with the same cubic CsPbBr3 core, but which are distinguished by the ligand composition and density. PeQD-1 features a binary didodecyldimethylammonium bromide (DDAB) and octanoic acid capping ligand system, with a high surface density of 1.53 nm−2, whereas PeQD-2 and PeQD-3 are coated by solely DDAB at a gradually lower surface density. We show that PeQD-1 endowed with highest ligand density features the highest dispersibility in toluene of 150 g/L, the highest photoluminescence quantum yield of 95% in dilute solution and 59% in a neat film, and the largest core-to-core spacing in neat thin films. We further establish that ions are released from the core of PeQD-1 when it is exposed to an electric field, although it comprises a dense coating of one capping ligand per four surface core atoms. We finally exploit these combined findings to the development of a light-emitting electrochemical cell (LEC), where the active layer is composed solely of solution-processed pure PeQDs, without additional electrolytes. In this device, the ion release is utilized as an advantage for the electrochemical doping process and efficient emissive operation of the LEC.
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| 21. |
- Qin, Xiao-Chuan, et al.
(författare)
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Evaluation of freeze-thaw damage on concrete material and prestressed concrete specimens
- 2016
-
Ingår i: Construction and Building Materials. - : Elsevier. - 0950-0618 .- 1879-0526. ; 125, s. 892-904
-
Tidskriftsartikel (refereegranskat)abstract
- The pore structure of the hardened concrete and the microscopic changes of a few selected pores throughout the freeze-thaw test were investigated by a method combining RapidAir and digital metalloscope. Traditional tests were also performed to evaluate the macroscopic change caused by freeze-thaw cycles (FTCs). The investigation shows that the concrete material, of which the spacing factor is 0.405 mm and the air content is 2.38%, can still withstand more than 300 FTCs. Severe microscopic damages occurred after approximately 200 FTCs and the freeze-thaw damage were gradually aggravated afterwards. Prestress forces have a remarkable impact on the failure pattern under FTCs. It was further found that the compressive strength as an indicator is more reliable than the relative dynamic modulus of elasticity in evaluating the freeze-thaw damage on concrete material. In addition, the test and analysis show that the measured prestress losses of bonded specimen are larger than that of unbounded specimen under the attack of FTCs due to the duct grouting effect. The ultimate freeze-thaw prestress loss is about 5% of σconσcon for both the bonded and unbonded specimens because the grouting cement paste will eventually be completely destroyed.
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| 22. |
- Sadaqat, Beenish, et al.
(författare)
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Thermophilic β-mannanases from bacteria : production, resources, structural features and bioengineering strategies
- 2024
-
Ingår i: World Journal of Microbiology and Biotechnology. - 0959-3993. ; 40:4
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Forskningsöversikt (refereegranskat)abstract
- β-mannanases are pivotal enzymes that cleave the mannan backbone to release short chain mannooligosaccharides, which have tremendous biotechnological applications including food/feed, prebiotics and biofuel production. Due to the high temperature conditions in many industrial applications, thermophilic mannanases seem to have great potential to overcome the thermal impediments. Thus, structural analysis of thermostable β-mannanases is extremely important, as it could open up new avenues for genetic engineering, and protein engineering of these enzymes with enhanced properties and catalytic efficiencies. Under this scope, the present review provides a state-of-the-art discussion on the thermophilic β-mannanases from bacterial origin, their production, engineering and structural characterization. It covers broad insights into various molecular biology techniques such as gene mutagenesis, heterologous gene expression, and protein engineering, that are employed to improve the catalytic efficiency and thermostability of bacterial mannanases for potential industrial applications. Further, the bottlenecks associated with mannanase production and process optimization are also discussed. Finally, future research related to bioengineering of mannanases with novel protein expression systems for commercial applications are also elaborated.
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| 23. |
- Shao, Chenwen, et al.
(författare)
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In Vivo Imaging of the Macrophage Migration Inhibitory Factor in Liver Cancer with an Activity-Based Probe
- 2021
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 93:4, s. 2152-2159
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Tidskriftsartikel (refereegranskat)abstract
- The macrophage migration inhibitory factor (MIF), a vital cytokine and biomarker, has been suggested to closely associate with the pathogenesis of liver cancer. However, a simple and effective approach for monitoring the change and distribution of cellular MIF is currently lacking and urgently needed, which could be helpful for a better understanding of its role in the progression of cancer. Herein, we report a novel activity-based probe, TPP2, which allows for direct labeling and imaging of endogenous MIF activity within live cells, clinical tissues, and in vivo in a mouse model of liver cancer. With this probe, we have intuitively observed the dynamic change of intracellular MIF activity by both flow cytometry and confocal imaging. We further found that TPP2 permits the identification and distinguishing of liver cancer in vitro and in vivo with high sensitivity and selectivity toward MIF. Our observations indicate that TPP2 could provide a promising new imaging approach for elucidating the MIF-related biological functions in liver cancer.
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| 24. |
- Shao, Jian-Yong
(författare)
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Basis for reclassification of nasopharyngeal carcinoma
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nasopharyngeal carcinoma (NPC) shows broad differences in racial and geographical distribution, radiosensitivity, and a multifactorial etiology. This thesis aims to identify molecular biomarkers with potentially valuable for prognostic implications in NPC. This thesis involved a series of studies which were performed on cohorts of patients with NPC to investigate the genetic alterations, Epstein-Barr virus (EBV) infection, and gene expression profiles, and to assess their correlations with clinicopathological parameters and survival of NPC patients. The results indicated that overexpression of caveolin-1 (Cav-1) and extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) in NPC were significantly associated with TNM stage, metastasis, and poor prognosis (Paper I). Loss of heterozygosity (LOH) on 9p21, 16q and 19q13 may be responsible for tumor aggression behavior and progression of NPC, with a possible interaction between allelic loss and EBV infection in the etiology of NPC (Paper II). EBV latent membrane protein (LMP) 1 overexpression was significantly correlated with p53 accumulation in NPC, CD8+ T cell infiltration, and matrix metalloproteinase (MMP) 9 overexpression in NPC cells. Moreover, plasma EBV DNA was detectable at a high frequency in primary NPC (96%). Higher plasma EBV-DNA levels were positively correlated with advanced TNM stages, lymph node metastasis, and NPC relapses (Papers III-V). Overexpression of LMP1 regulated the mTOR signaling pathway in NPC, possibly through phosphorylation of AKT/mammalian target of rapamycin (mTOR)/phospho-P70S6 kinase (P70S6K)/4EBP1. LMP1 expression was closely correlated with expression of p-mTOR, p-P70S6K and p-4EBP1 in NPC tumors, while expression levels of p-P70S6K, p-4EBP1 and LMP1 were significantly correlated with overall survival in NPC patients (Paper V). Paper VI presents a new molecular NPC-space vector modulation (SVM) classifier, which integrates sex and seven genes, including LMP1, CD147, Cav-1, p-P70S6K, MMP11, survivin, and secreted protein acidic and rich in cysteine (SPARC). This NPC-SVM classifier could refine the classification of NPC patients into high- and low-risk groups, which demonstrated significant differences in 5-year disease-specific survival (DSS) rates in a group of 411 validation patients (86.2% vs. 37.6%, p<0.001). Paper VII presents a new histological classification study, which was developed mainly on the basis of morphological characteristics and tumor cell differentiation. Of 3,839 tumors, 2,057 (53.6%) were histologically classified as undifferentiated epithelial cell carcinoma (UECC), 942 (24.5%) as undifferentiated mixed epithelial-sarcomatoid cell carcinoma (UESCC), 640 (16.7%) as undifferentiated sarcomatoid cell carcinoma (USCC), and 200 (5.2%) as squamous cell carcinoma (SCC). Based on the new histological classification system, the 5-year DSS rates were 76.4% for UECC, 66.0% for UESCC, 56.0% for USCC, and 32.7% for SCC. Stratified according to the new classification, patients with UECC and UESCC who received radiochemotherapy (RCT) showed better 5-year DSS rates than those who received radiotherapy (RT) alone. In summary, the results of these studies indicate that LOH, differentially-expressed genes, and EBV markers can act as prognostic biomarkers in NPC patients. The NPC-SVM classifier and the new proposed histopathological classification provide better discriminative prediction of NPC prognosis than the current WHO classification, as well as a means of monitoring the therapeutic efficacy of RCT and RT in advanced-stage NPC patients.
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| 25. |
- Shao, Xue-Feng, et al.
(författare)
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Screening of sugar alcohols and their binary eutectic mixtures as phase change materials for low-to-medium temperature thermal energy storage. (II) : Isothermal melting and crystallization behaviors
- 2019
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 180, s. 572-583
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Tidskriftsartikel (refereegranskat)abstract
- Based on the non-isothermal phase change behaviors of twenty-one pure and mixture sugar alcohols presented in our previous study (Part 1), the isothermal melting and crystallization behaviors were further tested in this supplemental work for five selected pure sugar alcohols (xylitol, erythritol, dmannitol, d-dulcitol and inositol) and their five binary eutectic mixtures to make an advanced screening of these candidates for low-to-medium temperature latent heat storage. The isothermal melting and crystallization behaviors of these ten candidates were tested at a constant degree of superheat (10 degrees C) and various degrees of subcooling up to 210 degrees C. The phase change temperatures, degrees of supercooling and durations of phase change were determined by the recorded temperature-history curves. It was found that the incrystallizable xylitol and its eutectic mixture of xylitol (75 mol%) + erythritol with low melting points under 100 degrees C are also unable to crystallize during isothermal cool-down at any degrees of subcooling (30-90 degrees C) due to the unavailability to nucleation. The rest eight crystallizable candidates all suffer from severe supercooling and are unable to crystallize at low degrees of subcooling (<20 degrees C). They undergo both one-phase supercooling due to poor nucleation performance and two-phase supercooling, which was unable to be obtained previously by non-isothermal cooling, due to slow crystallization kinetics. However, it seems difficult to find a correlation between the observed degrees of supercooling in both the liquid and solid phases and the prescribed degrees of subcooling by only three consecutive isothermal melting and crystallization cycles, as a result of the randomness of nucleation and large size of samples. The duration of crystallization was shown to decrease with increasing the degree of subcooling for both pure and mixture sugar alcohols due to the enhanced driving force for crystallization. The durations of crystallization of the mixture sugar alcohols appear to be longer than those of their pure compounds, due to the lower thermal conductivity and higher dynamic viscosity of the mixtures. Combining the present isothermal and the previous non-isothermal test results, it has been confirmed that the difficulty in crystallization and the severe supercooling are the primary issues for sugar alcohols, which must be addressed before they can be used in real-world latent heat storage systems.
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| 26. |
- Shao, Yue, et al.
(författare)
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Crosslinking of a Single Poly(ionic liquid) by Water into Porous Supramolecular Membranes
- 2020
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 59:39, s. 17187-17191
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Tidskriftsartikel (refereegranskat)abstract
- Reversible regulation of membrane microstructures via non-covalent interactions is of considerable interest yet remains a challenge. Herein, we discover a general one-step approach to fabricate supramolecular porous polyelectrolyte membranes (SPPMs) from a single poly(ionic liquid) (PIL). The experimental results and theoretical simulation suggested that SPPMs were formed by a hydrogen-bond-induced phase separation of a PIL between its polar and apolar domains, which were linked together by water molecules. This unique feature was capable of modulating microscopic porous architectures and thus the global mechanical property of SPPMs by a rational design of the molecular structure of PILs. Such SPPMs could switch porosity upon thermal stimuli, as exemplified by dynamically adaptive transparency to thermal fluctuation. This finding provides fascinating opportunities for creating multifunctional SPPMs.
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| 27. |
- Shao, Yue, et al.
(författare)
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Scalable Synthesis of Photoluminescent Single-Chain Nanoparticles by Electrostatic-Mediated Intramolecular Crosslinking
- 2022
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 61:27
-
Tidskriftsartikel (refereegranskat)abstract
- We report the large-scale synthesis of photoluminescent single-chain nanoparticles (SCNPs) by electrostatic-mediated intramolecular crosslinking in a concentrated solution of 40 mg mL−1 by continuous addition of the free radical initiator. Poly(vinyl benzyl chloride) was charged by quaternization with vinyl-imidazolium for the intramolecular crosslinking by using 2,2-dimethoxy-2-phenylacetophenone (DMAP) as the radical initiator. Under the electrostatic repulsion thus interchain isolation, the intrachain crosslinking experiences the transition from coil through pearl-necklace to globular state. The SCNPs demonstrate strong photoluminescence in the visible range when the non-emissive units are confined thereby. Composition and microstructure of the SCNPs are tunable. The photoluminescent tadpole-like Janus SCNP can be used to selectively illuminate interfacial membranes while stabilizing the emulsions.
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| 28. |
- Tinzl, Martina, et al.
(författare)
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Interaction between c-jun and Androgen Receptor Determines the Outcome of Taxane Therapy in Castration Resistant Prostate Cancer.
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- Taxane based chemotherapy is the standard of care treatment in castration resistant prostate cancer (CRPC). There is convincing evidence that taxane therapy affects androgen receptor (AR) but the exact mechanisms have to be further elucidated. Our studies identified c-jun as a crucial key player which interacts with AR and thus determines the outcome of the taxane therapy given. Docetaxel (Doc) and paclitaxel (Pac) agents showed different effects on LNCaP and LNb4 evidenced by alteration in the protein and mRNA levels of c-jun, AR and PSA. Docetaxel-induced phophorylation of c-jun occurred before JNK phosphorylation which suggests that c-jun phosphorylation is independent of JNK pathways in prostate cancer cells. A xenograft study showed that mice treated with Pac and bicalutamide showed worse outcome supporting our hypothesis that upregulation of c-jun might act as a potent antiapoptotic factor. We observed in our in vitro studies an inverse regulation of PSA- and AR-mRNA levels in Doc treated LNb4 cells. This was also seen for kallikrein 2 (KLK 2) which followed the same pattern. Given the fact that response to taxane therapy is measured by PSA decrease we have to consider that this might not reflect the true activity of AR in CRPC patients.
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| 29. |
- Tong, Yang, et al.
(författare)
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Progress of the key materials for organic solar cells
- 2020
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Ingår i: Science in China Series B. - Beijing, China : SCIENCE PRESS. - 1674-7291 .- 1869-1870. ; 63:6, s. 758-765
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Forskningsöversikt (refereegranskat)abstract
- Organic solar cells have attracted academic and industrial interests due to the advantages like lightweight, flexibility and roll-to-roll fabrication. Nowadays, 18% power conversion efficiency has been achieved in the state-of-the-art organic solar cells. The recent rapid progress in organic solar cells relies on the continuously emerging new materials and device fabrication technologies, and the deep understanding on film morphology, molecular packing and device physics. Donor and acceptor materials are the key materials for organic solar cells since they determine the device performance. The past 25 years have witnessed an odyssey in developing high-performance donors and acceptors. In this review, we focus on those star materials and milestone work, and introduce the molecular structure evolution of key materials. These key materials include homopolymer donors, D-A copolymer donors, A-D-A small molecular donors, fullerene acceptors and nonfullerene acceptors. At last, we outlook the challenges and very important directions in key materials development.
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| 30. |
- Wan, Cheng-Liang, et al.
(författare)
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Dynamics of slow electrons transmitting through straight glass capillary and tapered glass capillary
- 2016
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 65:20
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Tidskriftsartikel (refereegranskat)abstract
- It has been found that the transmission rate of the electrons through insulating capillaries as a function of time/incident charge is not the same as that of the ions. The question arises that by using the electrons, if the negative charge patches can be formed to facilitate the transmission of the following electrons, thereby substantiating that the so-called guiding effect works also for electrons. This study aims to observe the time evolutions of the transmission of electrons through a straight glass tube and a tapered glass capillary. This will reveal the details of how and (or) if the negative charge patches can be formed when the electrons transport through them. In this work, a set of MCP/phosphor two-dimensional detection system based on Labview platform is developed to obtain the time evolution of the angular distribution of the transmitted electrons. The pulsed electron beams are obtained to test our detection system. The time evolution of the angular profile of 1.5 keV electrons transmitting through the glass tube/capillary is observed. The transmitted electrons are observed on the detector for a very short time and disappear for a time and then appear again for both the glass tube and tapered glass capillary, leading to an oscillation. The positive charge patches are formed in the insulating glass tube and tapered glass capillary since the secondary electron emission coefficient for the incident energy is larger than 1. It is due to the fact that fast discharge of the deposited charge leads to the increase of the transmission rate, while the fast blocking of the incident electrons due to the deposited positive charge leads to the decrease of the transmission rate. The geometrical configuration of the taper glass capillary tends to make the secondary electrons deposited at the exit part to form the negative patches that facilitate the transmission of electrons. This suggests that if the stable transmission needs to be reached for producing the electron micro-beam by using tapered glass capillaries, the steps must be taken to have the proper grounding and shielding of the glass capillaries and tubes. Our results show a difference in transmission through the insulating capillary between electrons and highly charged ions.
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| 31. |
- Wang, Yi Pin, et al.
(författare)
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Performance of tuned mass dampers for vibration reduction in a tlp floating wind turbine
- 2020
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Ingår i: Proceedings of the International Offshore and Polar Engineering Conference. - 1098-6189 .- 1555-1792. ; 2020-October, s. 406-414
-
Konferensbidrag (refereegranskat)abstract
- Tension leg platform (TLP) floating wind turbines (FWTs) experience high-amplitude, dynamic structural vibrations under complex loading conditions. Tuned mass dampers (TMDs) are a simple yet effective means to reduce such loadings. This work focuses on load reduction by TMDs for the WindStar TLP system, and optimizes the TMDs’ parameters in a parametric study. Dynamic analysis then assesses FWTs with and without a TMD in a selected set of load cases. Results show that optimized TMD can reduce nacelle acceleration by up to 20%, especially in extreme conditions.
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| 32. |
- Wu, Hao Yu, et al.
(författare)
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Transient response of a TLP-type floating offshore wind turbine under tendon failure conditions
- 2021
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Ingår i: Ocean Engineering. - : Elsevier BV. - 0029-8018. ; 220
-
Tidskriftsartikel (refereegranskat)abstract
- Among various types of floating offshore wind turbines (FOWTs), the tension leg platform (TLP) floating wind turbines have relatively small motions due to stiff tendons. Similar to TLP applications in the offshore industry, tendon failure may lead to deteriorated stability and large transient responses, which should be considered as part of accidental limit state (ALS) checks at the design stage of the TLP FOWTs. This paper takes the WindStar TLP system as a representative and investigates the transient effects of one-tendon failure on the system responses. A coupled numerical model is first established using the aero-hydro-servo-elastic simulation tool FAST. Subsequent numerical simulations of tendon failure are carried out to consider different tendon breakage and turbine shutdown scenarios in both operational and parked conditions. Response statistics of key design parameters including platform motion, nacelle acceleration, and tendon tension are analyzed. The results indicate that several transient responses of the FOWT under operational conditions may be even higher than the extreme values under 50-year conditions. Our analyses also reveal that the shutdown strategies, if not applied appropriately, may have limited effects in reducing the responses of the FOWT, thus in certain scenarios threaten the safety of the tendon closest to the broken tendon if no other actions are taken. For the considered TLP FOWT, the ALS design requirements dominate over the ultimate limit state requirements. These findings can be relevant to the ALS design of TLP FOWTs.
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| 33. |
- Zhang, Yu Mei, et al.
(författare)
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Small-scale laterally-unrestrained corrugated web girders: (I) LTB tests and numerical validation
- 2022
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Ingår i: Thin-Walled Structures. - : Elsevier BV. - 0263-8231. ; 180
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Tidskriftsartikel (refereegranskat)abstract
- The lateral–torsional buckling (LTB) of corrugated web girders (CWGs), which have been used extensively in bridges worldwide, is investigated in this paper. In consideration that available flexural strength proposals of CWGs have been based largely on numerical/theoretical investigations, besides the scarce of physical tests and the risk of collapse by LTB, three small-scale simply-supported CWGs specimens are designed and tested, and their results are presented in this paper. An innovative test setup, containing special loading plates as well as end and lateral supports, is prepared to ensure that the tests are under pure bending moment through the four-point bending without any stabilising or destabilising effect for the applied load. The main test parameter is the web depth of the girders, while other parameters are evaluated numerically in the companion paper. Accordingly, the related experimental works are currently introduced and several conclusions are drawn. The effect of the web depth is evaluated, which shows that the ultimate buckling moments of the girders, and also the stiffness, increase with the increase in the girder's height. Moreover, the tests indicate that the too thin corrugated webs (CWs) may be affected by web distortion which may not be very obvious in the deformed configuration, even though CWs do not withstand longitudinal stress. The corresponding finite element (FE) models are then developed taking into account the elastic and inelastic buckling analyses. Through comparisons with the tests, FE simulations show good agreement and ability to provide the behaviour of small-scale CWGs. Accordingly, they are used to generate parametric studies in the companion paper with the goal of providing the fundamental behaviour of small-scale CWGs as well as appropriate design methods. Additionally, FE modelling outcomes confirm that the entire sections of CWGs do satisfy the plane section assumption.
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