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| 4. |
- Fan, Qunping, 1989, et al.
(författare)
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Weak Makes It Powerful: The Role of Cognate Small Molecules as an Alloy Donor in 2D/1A Ternary Fullerene Solar Cells for Finely Tuned Hierarchical Morphology in Thick Active Layers
- 2020
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Ingår i: Small Methods. - : Wiley. - 2366-9608. ; 4:3
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Tidskriftsartikel (refereegranskat)abstract
- Herein, a novel small molecule donor is first developed, FSM6, which is a cognate molecule to BTR possessing similar molecular structure with comparable optical absorption but different crystallinity. The efficient fullerene-type ternary small molecular solar cells (SMSCs) based on an alloy donor of BTR and FSM6 in a thick film of 250 nm reveal the improved hierarchical phase separation morphology and molecular structural order of ternary active layers with improved crystallinity of the key donor component BTR. Furthermore, FSM6 as the key third component also plays a role of charge transfer accelerator in ternary SMSCs. As a result, the optimal ternary SMSCs based on BTR:FSM6:PC71BM achieve a high power conversion efficiency (PCE) up to 10.21% with the synergistically improved open-circuit voltage of 0.950 V, short-circuit current density of 13.85 mA cm(-2), and fill factor of 77.6%, in comparison with either the binary SMSCs of BTR:PC71BM (PCE = 9.37%) or FSM6:PC71BM (PCE = 8.00%). This work provides a promising methodology to optimize device morphology for high-performance ternary SMSCs by combining two cognate small molecules with similar absorption spectra but different crystallinity as an alloy donor.
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| 5. |
- Fenstermacher, M.E., et al.
(författare)
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DIII-D research advancing the physics basis for optimizing the tokamak approach to fusion energy
- 2022
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 62:4
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Tidskriftsartikel (refereegranskat)abstract
- DIII-D physics research addresses critical challenges for the operation of ITER and the next generation of fusion energy devices. This is done through a focus on innovations to provide solutions for high performance long pulse operation, coupled with fundamental plasma physics understanding and model validation, to drive scenario development by integrating high performance core and boundary plasmas. Substantial increases in off-axis current drive efficiency from an innovative top launch system for EC power, and in pressure broadening for Alfven eigenmode control from a co-/counter-I p steerable off-axis neutral beam, all improve the prospects for optimization of future long pulse/steady state high performance tokamak operation. Fundamental studies into the modes that drive the evolution of the pedestal pressure profile and electron vs ion heat flux validate predictive models of pedestal recovery after ELMs. Understanding the physics mechanisms of ELM control and density pumpout by 3D magnetic perturbation fields leads to confident predictions for ITER and future devices. Validated modeling of high-Z shattered pellet injection for disruption mitigation, runaway electron dissipation, and techniques for disruption prediction and avoidance including machine learning, give confidence in handling disruptivity for future devices. For the non-nuclear phase of ITER, two actuators are identified to lower the L-H threshold power in hydrogen plasmas. With this physics understanding and suite of capabilities, a high poloidal beta optimized-core scenario with an internal transport barrier that projects nearly to Q = 10 in ITER at ∼8 MA was coupled to a detached divertor, and a near super H-mode optimized-pedestal scenario with co-I p beam injection was coupled to a radiative divertor. The hybrid core scenario was achieved directly, without the need for anomalous current diffusion, using off-axis current drive actuators. Also, a controller to assess proximity to stability limits and regulate β N in the ITER baseline scenario, based on plasma response to probing 3D fields, was demonstrated. Finally, innovative tokamak operation using a negative triangularity shape showed many attractive features for future pilot plant operation.
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| 6. |
- Wang, Xiangjian, et al.
(författare)
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Multifunctionality in (K,Na)NbO3-based ceramic near polymorphic phase boundary
- 2021
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Ingår i: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 130:6
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Tidskriftsartikel (refereegranskat)abstract
- The 0.95K0.42Na0.58Nb0.96Sb0.04O3–0.02BaZrO3–0.03Bi0.5K0.5HfO3 ceramic was fabricated via a conventional solid-state reaction. This ceramic exhibits the diffuse polymorphic phase boundary (PPB) near room temperature. The dielectric, ferroelectric, electromechanical, electrocaloric, and dielectric energy storage properties were studied systemically. The normalized large signal d33* values are approximately 400–600 pm/V at measured temperatures and electric fields, which are larger than or comparable with the values reported in other lead-free compositions. The electrocaloric strength is enhanced at the broad region of PPB provided by the indirect and direct measurements. At low field of 30 kV/cm, the dielectric energy storage is ∼0.12–018 J/cm3 at relative broad temperature range due to the diffuse nature of polymorphic phase boundary. Theoretical simulations reveal that multi-element dopants, such as Sb5+, Hf4+, Zr4+, and Bi3+ ions, could induce the breaking of local structure symmetry in the orthorhombic phase to form the PPB. In addition, the charge distribution may also break the long-range ferroelectric order through the analysis of Bader charge. Our study suggests that the K0.5Na0.5NbO3-based ceramic exhibits improved performance and good thermal stability in piezoelectric, electrocaloric, and dielectric energy storage characteristics in terms of the design of multi-element dopants to form the PPB and it will benefit the promising applications in electronic devices.
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| 7. |
- Chen, Gaojian, et al.
(författare)
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A modular click approach to glycosylated polymeric beads : Design, synthesis and preliminary lectin, recognition studies
- 2007
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Ingår i: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 40:21, s. 7513-7520
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Tidskriftsartikel (refereegranskat)abstract
- Covalent immobilization of a range of carbohydrate derivatives onto polymeric resin beads is described. Copper-catalyzed Huisgen [2 + 3] cycloaddition (often termed click chemistry) was used to graft mannose-containing azides to complementarily functionalized alkyne surfaces, namely (a) Wang resin or (b) Rasta particles consisting of a clickable alkyne polymer loose outer shell and a Wang resin inner core. For the second approach, Wang resin beads were first converted into immobilized living radical polymerization initiators with subsequent polymerization of trimethylsilanyl-protected propargyl methacrylate followed by deprotection with TBAF to yield the desired polyalkyne clickable scaffold. The appropriate (x-mannopyranoside azide was then clicked onto the bead to give a mannose functionalized Rasta resin. IR, gel-phase H-1 NMR, and elemental analysis have been used to characterize the modified resins. The binding abilities of these D-mannose-modified particles were subsequently tested using fluorescein-labeled Concanavalin A (Con A), a lectin that binds certain mannose-containing molecules. Preliminary results indicated that the novel glyco-hybrid materials presented in this work are able to efficiently recognize mannose-binding model lectins such as Con A, opening the way for their potential application in affinity chromatography, sensors, and other protein recognition/separation fields.
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| 8. |
- Geng, Jianping, et al.
(författare)
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A Silent Infection Pandemic of COVID-19 : Epidemiological Investigation and Hypothetical Models
- 2020
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Ingår i: Canadian Journal of Infectious Diseases and Medical Microbiology. - : HINDAWI LTD. - 1712-9532 .- 1918-1493. ; 2020
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Tidskriftsartikel (refereegranskat)abstract
- To explore the epidemic mode of COVID-19, we made an epidemiological investigation, set up hypothetical models, and compared them with hepatitis A virus (HAV) age-specific epidemic characteristic. In the epidemiological investigation, we reported the first familial COVID-19 silent infection in the world. A 19-year-old healthy female COVID-19 virus carrier without any symptoms caused two mild and one severe pneumonia. In hypothetical models, the silent infection rate ranges from 60% to 80% based on 3 sources: China mainland, evacuation of 4 nationals, and the ship "Diamond Princess," respectively. In comparison with HAV, COVID-19 shows the same infection mode in children (aged 0-9 years), but significant difference in young adults (aged 10-44 years) and the elderly (aged 45 years or older). Therefore, we prejudged that COVID-19 is a silent infection pandemic mainly in young adults but threatens the elderly.
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| 9. |
- Geng, Xiongfei, et al.
(författare)
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Exploring High-energy Emission from the BL Lacertae Object S5 0716+714 with the Fermi Large Area Telescope
- 2020
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 904:1
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Tidskriftsartikel (refereegranskat)abstract
- We present the results of an extensive gamma-ray data analysis of the emission from the blazar S5 0716+714 with the primary motivation to study its temporal and spectral variability behavior. In this work, we extract a 10 days binned gamma-ray light curve from 2008 August 4 to 2016 April 27 in the energy range of 0.1-300 GeV and identify six outburst periods with peak flux of >4 x 10(-7) ph cm(-2) s(-1) from this highly variable source. The brightest flares are identified by zooming in these outburst periods to 1 day binning and using the Bayesian Blocks algorithm. The fastest variability timescale is found to be 1.5 0.3 hr at MJD 57128.01 0.01 with a peak flux above 100 MeV of (26.8 6.9) x 10(-7) ph cm(-2) s(-1). No hint of periodic modulations has been detected for the light curve of S5 0716+714. During the outburst phases, the gamma-ray spectrum shows an obvious spectral break with a break energy between 0.93 and 6.90 GeV energies, which may be caused by an intrinsic break in the energy distribution of radiating particles. The five highest-energy photons, with E > 100 GeV, imply that the high-energy emission from this source may originate from a moving emission region in a helical path upstream in the jet. The spectral behavior and temporal characteristics of the individual flares indicate that the location of the emission region lies in the sub-parsec scale (r(gamma) < 0.85 pc).
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| 10. |
- Guo, Shaoyong, et al.
(författare)
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Human Error Influence on the System Sensitivity of the Laser-assisted Navigation Calibration Instrument
- 2021
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Ingår i: ICRSA 2021. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450384940 ; , s. 23-29
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Konferensbidrag (refereegranskat)abstract
- *In the curved navigation of a wall-climbing robot, a laser navigation calibration instrument is designed to help the robot position on the wall. Human error can interfere with the input data in navigation, resulting in the decline of the output data's accuracy. In this paper, we analyze the sensitivity index of human errors in the process of navigation. There are several methods in the literature to determine the sensitivity indices of various human errors. Researchers have provided its validity. Compared with the Nonparametric Spearman rank-order correlation method, the simple analysis of variance technique, and the connection weight method, the Mean Impact Value (MIV) algorithm allows the effect of the output variables corresponding to each perturbation in the input variable to be recorded. As a machine learning method widely used in data analysis, BP neural network can significantly improve the experimental efficiency. The paper applied a technique to study the sensitivity index of human errors in navigation. This method integrates the Mean Impact Value (MIV) algorithm with BP neural network model by MATLAB. In the experiment, one thousand arrays of data are generated according to the paper of Design of a Laser-based Calibration instrument for Robot's Location Positioning on A Curved Surface. And these one thousand arrays of data are used to train a BP neural network model by MATLAB. The result of the BP neural network model is reliable, with the whole R is 0.99341. Due to the perturbations caused by each human error, five hundred arrays of data are generated in the input variable. This sensitivity analysis method could obtain an array of mean impact variables of human error by the MIV algorithm, which corresponds to each perturbation in the input variable. The results indicate that the perturbations caused by human error in the laser rotation angle a are greater than those in the laser-assisted navigation calibration instrument's original coordinate position. And the output variables increase linearly with the increase of the input error.
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| 11. |
- Hudson, Thomas J., et al.
(författare)
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International network of cancer genome projects
- 2010
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 464:7291, s. 993-998
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Tidskriftsartikel (refereegranskat)abstract
- The International Cancer Genome Consortium (ICGC) was launched to coordinate large-scale cancer genome studies in tumours from 50 different cancer types and/or subtypes that are of clinical and societal importance across the globe. Systematic studies of more than 25,000 cancer genomes at the genomic, epigenomic and transcriptomic levels will reveal the repertoire of oncogenic mutations, uncover traces of the mutagenic influences, define clinically relevant subtypes for prognosis and therapeutic management, and enable the development of new cancer therapies.
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| 12. |
- Li, Shuai, et al.
(författare)
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Grid-Search Enhanced Tree-Based Machine Learning for Traffic IoT Data Anomaly Detection
- 2022
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Ingår i: Proceedings of the 12th International Conference on Computer Engineering and Networks. - Singapore : Springer Science+Business Media B.V.. - 9789811969003 ; , s. 3-9
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Konferensbidrag (refereegranskat)abstract
- Anomaly detection is an important part of machine learning. Detection of outliers in the field of transportation can provide valid data for future traffic predictions or traffic flow analysis. This paper builds a model based on XGBoost to detect outliers in IoT data. The data is preprocessed first, followed by model building. Then we use the grid search to adjust the parameters and substitute the optimal parameters into the building model. To validate the model, we cross-checked it with two benchmark models, iFroset and Random Forest. The final experimental results show that the model constructed in this paper can accurately detect outliers in traffic flow and the accuracy is better than that of the baseline model. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
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| 13. |
- Sun, Bin, 1988-, et al.
(författare)
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A Robust Data-Driven Method for Multiseasonality and Heteroscedasticity in Time Series Preprocessing
- 2021
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Ingår i: Wireless Communications & Mobile Computing. - : Wiley-Hindawi. - 1530-8669 .- 1530-8677. ; 2021
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Tidskriftsartikel (refereegranskat)abstract
- Internet of Things (IoT) is emerging, and 5G enables much more data transport from mobile and wireless sources. The data to be transmitted is too much compared to link capacity. Labelling data and transmit only useful part of the collected data or their features is a promising solution for this challenge. Abnormal data are valuable due to the need to train models and to detect anomalies when being compared to already overflowing normal data. Labelling can be done in data sources or edges to balance the load and computing between sources, edges, and centres. However, unsupervised labelling method is still a challenge preventing to implement the above solutions. Two main problems in unsupervised labelling are long-term dynamic multiseasonality and heteroscedasticity. This paper proposes a data-driven method to handle modelling and heteroscedasticity problems. The method contains the following main steps. First, raw data are preprocessed and grouped. Second, main models are built for each group. Third, models are adapted back to the original measured data to get raw residuals. Fourth, raw residuals go through deheteroscedasticity and become normalized residuals. Finally, normalized residuals are used to conduct anomaly detection. The experimental results with real-world data show that our method successfully increases receiver-operating characteristic (AUC) by about 30%.
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| 15. |
- Zhang, Lu, et al.
(författare)
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Boosting Machine Learning Algorithms with Grid-Search for Transport IoT Data Prediction
- 2022
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Ingår i: Proceedings of the 12th International Conference on Computer Engineering and Networks. - Singapore : Springer Science+Business Media B.V.. - 9789811969003 ; , s. 903-910
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Konferensbidrag (refereegranskat)abstract
- IoT (internet of things) data is a topic we have discussed a lot in recent years. Traffic data is an important part of IoT data. Traffic flow prediction not only facilitates people’s travel and saves our time, but also provides effective technical support for highway traffic control and scheduling. To achieve accurate traffic flow prediction, this study aims to build a machine learning-based traffic flow prediction model. We first screen out the features that have a greater impact on traffic flow. On this basis, this work establishes a traffic flow prediction model based on CatBoost. By comparing with other machine learning models, conclusions can be drawn: CatBoost model can accurately predict traffic flow; CatBoost outperforms traditional machine learning models. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
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| 16. |
- Zhang, Xiaoyu, et al.
(författare)
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Causality assessment of circulating Vitamin D level on venous thromboembolism : A Mendelian randomization study
- 2023
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Ingår i: Nutrition, Metabolism and Cardiovascular Diseases. - 0939-4753. ; 33:9, s. 1800-1807
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Tidskriftsartikel (refereegranskat)abstract
- Background and aims: The associations of vitamin D level with venous thromboembolism (VTE) reported in observational studies, whereas these causal associations were uncertain in European population. Therefore, we used Mendelian randomization (MR) method to explore the causal associations between 25-hydroxyvitamin D (25(OH)D) concentrations and the risk of VTE and its subtypes [including deep vein thrombosis (DVT) and pulmonary embolism (PE)]. Methods and results: We used three kinds of genetic instruments to proxy the exposure of 25(OH)D, including genetic variants significantly associated with 25(OH)D, expression quantitative trait loci of 25(OH)D target genes, and genetic variants within or nearby 25(OH)D target genes. MR analyses did not provide any evidence for the associations of 25(OH)D levels with VTE and its subtypes (p > 0.05). The summary-data-based MR (SMR) analyses indicated that elevated expression of VDR was associated with decreased risk of VTE (OR = 0.81; 95% CI, 0.65–0.998; p = 0.047) and PE (OR = 0.67; 95% CI, 0.50–0.91; p = 0.011), and expression of AMDHD1 was associated with PE (OR = 0.93; 95% CI, 0.88–0.99; p = 0.027). MR analysis provided a significant causal effect of 25(OH)D level mediated by gene AMDHD1 on PE risk (OR = 0.09; 95% CI, 0.01–0.60; p = 0.012). Conclusion: Our MR analysis did not support causal association of 25(OH)D level with the risk of VTE and its subtypes. In addition, the expression of VDR and AMDHD1 involved in vitamin D metabolism showed a strong association with VTE or PE and might represent targets for these conditions.
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| 17. |
- Zhang, Yang, et al.
(författare)
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Wave power extraction and coastal protection by a periodic array of oscillating buoys embedded in a breakwater
- 2022
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Ingår i: Renewable energy. - : Elsevier. - 0960-1481 .- 1879-0682. ; 190, s. 434-456
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Tidskriftsartikel (refereegranskat)abstract
- The integration of wave energy devices and coastal structures may be an innovative and sustainable way to achieve energy production purposes with a secondary benefit of coastal protection, which can increase accessibility and reduce the costs of wave energy technology. In this paper, a 3-D theoretical model was developed to investigate the hydrodynamic efficiency and breakwater function of a periodic array of oscillating buoys embedded in a caisson breakwater. The generalized radiation problem was solved to derive generalized radiation force. The theoretical model was validated using Haskind's relation and energy flux conservation law. The influences of wave/geometrical parameters and PTO damping were revealed. In particular, hydrodynamic phenomenon of multiple orders reflected and transmitted propagating waves and their influence on wave power extraction and coastal protection was examined. Results show that a satisfactory hydrodynamic efficiency and coastal defense are realized simultaneously under oblique waves for this proposed system. A decline of hydrodynamic efficiency is found beyond a critical wavenumber, accompanied by the occurrence of the strong reflection phenomenon. The findings of this paper contribute towards the preliminary design of the hybrid breakwater-WEC system for the synergy effect between the wave energy devices and breakwaters.
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