| 1. |
- Kristan, Matej, et al.
(författare)
-
The Visual Object Tracking VOT2015 challenge results
- 2015
-
Ingår i: Proceedings 2015 IEEE International Conference on Computer Vision Workshops ICCVW 2015. - : IEEE. - 9780769557205 ; , s. 564-586
-
Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge 2015, VOT2015, aims at comparing short-term single-object visual trackers that do not apply pre-learned models of object appearance. Results of 62 trackers are presented. The number of tested trackers makes VOT 2015 the largest benchmark on short-term tracking to date. For each participating tracker, a short description is provided in the appendix. Features of the VOT2015 challenge that go beyond its VOT2014 predecessor are: (i) a new VOT2015 dataset twice as large as in VOT2014 with full annotation of targets by rotated bounding boxes and per-frame attribute, (ii) extensions of the VOT2014 evaluation methodology by introduction of a new performance measure. The dataset, the evaluation kit as well as the results are publicly available at the challenge website(1).
|
|
| 2. |
- Kristan, Matej, et al.
(författare)
-
The Visual Object Tracking VOT2016 Challenge Results
- 2016
-
Ingår i: COMPUTER VISION - ECCV 2016 WORKSHOPS, PT II. - Cham : SPRINGER INT PUBLISHING AG. - 9783319488813 - 9783319488806 ; , s. 777-823
-
Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2016 aims at comparing short-term single-object visual trackers that do not apply pre-learned models of object appearance. Results of 70 trackers are presented, with a large number of trackers being published at major computer vision conferences and journals in the recent years. The number of tested state-of-the-art trackers makes the VOT 2016 the largest and most challenging benchmark on short-term tracking to date. For each participating tracker, a short description is provided in the Appendix. The VOT2016 goes beyond its predecessors by (i) introducing a new semi-automatic ground truth bounding box annotation methodology and (ii) extending the evaluation system with the no-reset experiment.
|
|
| 3. |
- Yilimulati, Mihebai, et al.
(författare)
-
Regulation of Photosynthesis in Bloom-Forming Cyanobacteria with the Simplest β-Diketone
- 2021
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:20, s. 14173-14184
-
Tidskriftsartikel (refereegranskat)abstract
- Selective inhibition of photosynthesis is a fundamental strategy to solve the global challenge caused by harmful cyanobacterial blooms. However, there is a lack of specificity of the currently used cyanocides, because most of them act on cyanobacteria by generating nontargeted oxidative stress. Here, for the first time, we find that the simplest β-diketone, acetylacetone, is a promising specific cyanocide, which acts on Microcystis aeruginosa through targeted binding on bound iron species in the photosynthetic electron transport chain, rather than by oxidizing the components of the photosynthetic apparatus. The targeted binding approach outperforms the general oxidation mechanism in terms of specificity and eco-safety. Given the essential role of photosynthesis in both natural and artificial systems, this finding not only provides a unique solution for the selective control of cyanobacteria but also sheds new light on the ways to modulate photosynthesis.
|
|
| 4. |
- Chi, Chaodan, et al.
(författare)
-
Si-based InGaAs photodetectors on heterogeneous integrated substrate
- 2021
-
Ingår i: Science China: Physics, Mechanics and Astronomy. - : Springer Science and Business Media LLC. - 1674-7348 .- 1869-1927. ; 64:6
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, InGaAs p-i-n photodetectors (PDs) on an InP/SiO2/Si (InPOI) substrate fabricated by ion-slicing technology are demonstrated and compared with the identical device on a commercial InP substrate. The quality of epitaxial layers on the InPOI substrate is similar to that on the InP substrate. The photo responsivities of both devices measured at 1.55 µm are comparable, which are about 0.808–0.828 A W−1. Although the dark current of PD on the InPOI substrate is twice as high as that of PD on the InP substrate at 300 K, the peak detectivities of both PDs are comparable. In general, the overall performance of the InPOI-based PD is comparable to the InP-based PD, demonstrating that the ion-slicing technology is a promising route to enable the high-quality Si-based InP platform for the full photonic integration on a Si substrate.
|
|
| 5. |
- Guo, Ming, et al.
(författare)
-
alpha-Mangostin Extraction from the Native Mangosteen (Garcinia mangostana L.) and the Binding Mechanisms of alpha-Mangostin to HSA or TRF
- 2016
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:9
-
Tidskriftsartikel (refereegranskat)abstract
- In order to obtain the biological active compound, alpha-mangostin, from the traditional native mangosteen (Garcinia mangostana L.), an extraction method for industrial application was explored. A high yield of a-mangostin (5.2%) was obtained by extraction from dried mangosteen pericarps with subsequent purification on macroporous resin HPD-400. The chemical structure of alpha-mangostin was verified mass spectrometry (MS), nuclear magnetic resonance (H-1 NMR and C-13 NMR), infrared spectroscopy (IR) and UV-Vis spectroscopy. The purity of the obtained alpha-mangostin was 95.6% as determined by HPLC analysis. The binding of native alpha-mangostin to human serum albumin (HSA) or transferrin (TRF) was explored by combining spectral experiments with molecular modeling. The results showed that amangostin binds to HSA or TRF as static complexes but the binding affinities were different in different systems. The binding constants and thermodynamic parameters were measured by fluorescence spectroscopy and absorbance spectra. The association constant of HSA or TRF binding to alpha-mangostin is 6.4832x10(5) L/mol and 1.4652x10(5) L/mol at 298 K and 7.8619x10(5) L/mol and 1.1582x10(5) L/mol at 310 K, respectively. The binding distance, the energy transfer efficiency between alpha-mangostin and HSA or TRF were also obtained by virtue of the Forster theory of non-radiation energy transfer. The effect of alpha-mangostin on the HSA or TRF conformation was analyzed by synchronous spectrometry and fluorescence polarization studies. Molecular docking results reveal that the main interaction between amangostin and HSA is hydrophobic interactions, while the main interaction between alpha-mangostin and TRF is hydrogen bonding and Van der Waals forces. These results are consistent with spectral results.
|
|
| 6. |
- Chen, Mingming, et al.
(författare)
-
Carbon anode in direct carbon fuel cell
- 2010
-
Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 35:7, s. 2732-2736
-
Tidskriftsartikel (refereegranskat)abstract
- Direct carbon fuel cell (DCFC) is a kind of high temperature fuel cell using carbon materials directly as anode. Electrochemical reactivity and surface property of carbon were taken into account in this paper. Four representative carbon samples were selected. The most suitable ratio of the ternary eutectic mixture Li2CO3-K2CO3-Al2O3 was determined at 1.05:1.2:1(mass ration). Conceptual analysis for electrochemical reactivity of carbon anode shows the importance of (1) reactive characteristics including lattice disorder, edge-carbon ratio and the number of short alkyl side chain of carbon material, which builds the prime foundation of the anodic half-cell reaction; (2) surface wetting ability, which assures the efficient contact of anode surface with electrolyte. It indicates that anode reaction rate and DCFC output can be notably improved if carbon are pre-dispersed into electrolyte before acting as anode, due to the straightway shift from cathode to anode for CO32- provided by electrolyte soaked in carbon material.
|
|
| 7. |
- Lin, Jiajie, et al.
(författare)
-
Wafer-scale heterogeneous integration InP on trenched Si with a bubble-free interface
- 2020
-
Ingår i: APL Materials. - : AIP Publishing. - 2166-532X. ; 8:5
-
Tidskriftsartikel (refereegranskat)abstract
- Heterogeneous integration of compound semiconductors on a Si platform leads to advanced device applications in the field of Si photonics and high frequency electronics. However, the unavoidable bubbles formed at the bonding interface are detrimental for achieving a high yield of dissimilar semiconductor integration by the direct wafer bonding technology. In this work, lateral outgassing surface trenches (LOTs) are introduced to efficiently inhibit the bubbles. It is found that the chemical reactions in InP-Si bonding are similar to those in Si-Si bonding, and the generated gas can escape via the LOTs. The outgassing efficiency is dominated by LOTs' spacing, and moreover, the relationship between bubble formation and the LOT's structure is well described by a thermodynamic model. With the method explored in this work, a 2-in. bubble-free crystalline InP thin film integrated on the Si substrate with LOTs is obtained by the ion-slicing and wafer bonding technology. The quantum well active region grown on this Si-based InP film shows a superior photoemission efficiency, and it is found to be 65% as compared to its bulk counterpart.
|
|
| 8. |
- Muus, Christoph, et al.
(författare)
-
Single-cell meta-analysis of SARS-CoV-2 entry genes across tissues and demographics
- 2021
-
Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 27:3, s. 546-559
-
Tidskriftsartikel (refereegranskat)abstract
- Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular entry, and their expression may shed light on viral tropism and impact across the body. We assessed the cell-type-specific expression of ACE2, TMPRSS2 and CTSL across 107 single-cell RNA-sequencing studies from different tissues. ACE2, TMPRSS2 and CTSL are coexpressed in specific subsets of respiratory epithelial cells in the nasal passages, airways and alveoli, and in cells from other organs associated with coronavirus disease 2019 (COVID-19) transmission or pathology. We performed a meta-analysis of 31 lung single-cell RNA-sequencing studies with 1,320,896 cells from 377 nasal, airway and lung parenchyma samples from 228 individuals. This revealed cell-type-specific associations of age, sex and smoking with expression levels of ACE2, TMPRSS2 and CTSL. Expression of entry factors increased with age and in males, including in airway secretory cells and alveolar type 2 cells. Expression programs shared by ACE2(+)TMPRSS2(+) cells in nasal, lung and gut tissues included genes that may mediate viral entry, key immune functions and epithelial-macrophage cross-talk, such as genes involved in the interleukin-6, interleukin-1, tumor necrosis factor and complement pathways. Cell-type-specific expression patterns may contribute to the pathogenesis of COVID-19, and our work highlights putative molecular pathways for therapeutic intervention. An integrated analysis of over 100 single-cell and single-nucleus transcriptomics studies illustrates severe acute respiratory syndrome coronavirus 2 viral entry gene coexpression patterns across different human tissues, and shows association of age, smoking status and sex with viral entry gene expression in respiratory cell populations.
|
|
| 9. |
- Tao, Feng, et al.
(författare)
-
Convergence in simulating global soil organic carbon by structurally different models after data assimilation
- 2024
-
Ingår i: Global Change Biology. - 1354-1013 .- 1365-2486. ; 30:5
-
Tidskriftsartikel (refereegranskat)abstract
- Current biogeochemical models produce carbon–climate feedback projections with large uncertainties, often attributed to their structural differences when simulating soil organic carbon (SOC) dynamics worldwide. However, choices of model parameter values that quantify the strength and represent properties of different soil carbon cycle processes could also contribute to model simulation uncertainties. Here, we demonstrate the critical role of using common observational data in reducing model uncertainty in estimates of global SOC storage. Two structurally different models featuring distinctive carbon pools, decomposition kinetics, and carbon transfer pathways simulate opposite global SOC distributions with their customary parameter values yet converge to similar results after being informed by the same global SOC database using a data assimilation approach. The converged spatial SOC simulations result from similar simulations in key model components such as carbon transfer efficiency, baseline decomposition rate, and environmental effects on carbon fluxes by these two models after data assimilation. Moreover, data assimilation results suggest equally effective simulations of SOC using models following either first-order or Michaelis–Menten kinetics at the global scale. Nevertheless, a wider range of data with high-quality control and assurance are needed to further constrain SOC dynamics simulations and reduce unconstrained parameters. New sets of data, such as microbial genomics-function relationships, may also suggest novel structures to account for in future model development. Overall, our results highlight the importance of observational data in informing model development and constraining model predictions.
|
|
| 10. |
- Tao, Feng, et al.
(författare)
-
Microbial carbon use efficiency promotes global soil carbon storage
- 2023
-
Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 618:7967, s. 981-985
-
Tidskriftsartikel (refereegranskat)abstract
- Soils store more carbon than other terrestrial ecosystems. How soil organic carbon (SOC) forms and persists remains uncertain, which makes it challenging to understand how it will respond to climatic change. It has been suggested that soil microorganisms play an important role in SOC formation, preservation and loss. Although microorganisms affect the accumulation and loss of soil organic matter through many pathways, microbial carbon use efficiency (CUE) is an integrative metric that can capture the balance of these processes. Although CUE has the potential to act as a predictor of variation in SOC storage, the role of CUE in SOC persistence remains unresolved. Here we examine the relationship between CUE and the preservation of SOC, and interactions with climate, vegetation and edaphic properties, using a combination of global-scale datasets, a microbial-process explicit model, data assimilation, deep learning and meta-analysis. We find that CUE is at least four times as important as other evaluated factors, such as carbon input, decomposition or vertical transport, in determining SOC storage and its spatial variation across the globe. In addition, CUE shows a positive correlation with SOC content. Our findings point to microbial CUE as a major determinant of global SOC storage. Understanding the microbial processes underlying CUE and their environmental dependence may help the prediction of SOC feedback to a changing climate.
|
|
| 11. |
- Xiong, Binyu, et al.
(författare)
-
Numerical analysis of vanadium redox flow batteries considering electrode deformation under various flow fields
- 2023
-
Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 564
-
Tidskriftsartikel (refereegranskat)abstract
- The porous electrode of vanadium redox flow batteries (VRBs) is subject to deformation due to mechanical stress during stack assembling. The forces compress the electrode fiber into the flow channel and thus alter the electrode porosity ratio. Due to the complex mechanisms, the effects of resulting electrode morphological changes on VRB performance were usually ignored in existing studies. This paper proposes a three-dimensional VRB model considering the uneven electrode deformation to investigate the cell performance under different electrode compression ratios with three flow-field designs. Compression ratio (CR) and the intrusive part of the electrode are obtained under various mechanical stress by adjusting gasket thickness in the experiment. The proposed electrochemical model is established based on the comprehensive description of conservation laws and analyzed using the COMSOL platform. Three indices, namely the concentration overpotential, pressure drop, and distribution uniformity, are selected for the analysis under the three flow field designs and different CRs. The numerical study reveal that the pressure drop and the concentration overpotential are sensitive to the CR but less affected by the concentration uniformity. The minimum overpotential can be reached when the CR is around 40%–50%, depending on flow field designs, while a higher CR can cause a drastically increased pressure drop. It is also found that the interdigitated flow field with a CR of 45% is considered optimal. The insights from the proposed method demonstrate the significance of considering the effects of electrode deformation in the stack design under various flow fields.
|
|
| 12. |
- Xu, Sihong, et al.
(författare)
-
Carbon doped MO-SDC material as an SOFC anode
- 2007
-
Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 165:1, s. 82-86
-
Tidskriftsartikel (refereegranskat)abstract
- Oxide mixtures MO-SDC, M=Cu, Ni, Co, SDC=Ce0.9Sm0.1O1.95 were synthesized by employing a citrate/nitrate combustion technique. Two kinds of Carbon materials, activated carbon (AC) and vapor grown carbon fiber (VGCF) were homogeneously dispersed into the MO-SDC. The materials can be used as anodes to fabricate single cells using a uniaxial die-press method. The sintering temperature was studied to optimize cell performance. Experimental results showed that cells sintered at 700 degrees C had better performance. When the temperature was above 750 degrees C, the cells were severely distorted, and cannot be tested. Compared with the basic MO-SDC anode, AC and VGCF improve the solid oxide fuel cell (SOFC) anode properties, due to a change of the microstructures of the anode materials which enhance their electron conductivity. Single cell performances were evaluated by I-V measurements, and when 1.25 wt.%VGCF was introduced into the MO-SDC by ball-milling, termed: 1.25 wt.%VGCF-MO-SDC, the 1.25 wt.%VGCF-MO-SDC anode material could achieve the highest power density of up to 0.326 W cm(-2) with H-2 as fuel. The calcination temperature of the MO-SDC dry gel also strongly influenced the electrochemical performance of the 1.25 wt.%VGCF-MO-SDC material. XRD spectra for each calcined temperature and the I-V measurement both suggest that calcinations at 550 degrees C for 1 h are suitable. 1.0 wt.%AC-MO-SDC and 1.25 wt.%VGCF-MO-SDC have similar performance when the cell was fed in methanol/3%H2O, and the corresponding power density was up to 0.253 W cm(-2). Traces of carbon were found in the off-gases.
|
|
| 13. |
- Zhai, Panlong, et al.
(författare)
-
Engineering single-atomic ruthenium catalytic sites on defective nickel-iron layered double hydroxide for overall water splitting
- 2021
-
Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Rational design of single atom catalyst is critical for efficient sustainable energy conversion. However, the atomic-level control of active sites is essential for electrocatalytic materials in alkaline electrolyte. Moreover, well-defined surface structures lead to in-depth understanding of catalytic mechanisms. Herein, we report a single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets (Ru-1/D-NiFe LDH). Under precise regulation of local coordination environments of catalytically active sites and the existence of the defects, Ru-1/D-NiFe LDH delivers an ultralow overpotential of 18mV at 10mAcm(-2) for hydrogen evolution reaction, surpassing the commercial Pt/C catalyst. Density functional theory calculations reveal that Ru-1/D-NiFe LDH optimizes the adsorption energies of intermediates for hydrogen evolution reaction and promotes the O-O coupling at a Ru-O active site for oxygen evolution reaction. The Ru-1/D-NiFe LDH as an ideal model reveals superior water splitting performance with potential for the development of promising water-alkali electrocatalysts. Rational design of single atom catalyst is critical for efficient sustainable energy conversion. Single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets achieve superior HER and OER performance in alkaline media.
|
|
| 14. |
- Zhang, Xiaomeng, et al.
(författare)
-
Engineering Single-Atomic Ni-N-4-O Sites on Semiconductor Photoanodes for High-Performance Photoelectrochemical Water Splitting
- 2021
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 143:49, s. 20657-20669
-
Tidskriftsartikel (refereegranskat)abstract
- Direct photoelectrochemical (PEC) water splitting is a promising solution for solar energy conversion; however, there is a pressing bottleneck to address the intrinsic charge transport for the enhancement of PEC performance. Herein, a versatile coupling strategy was developed to engineer atomically dispersed Ni-N-4 sites coordinated with an axial direction oxygen atom (Ni-N-4-O) incorporated between oxygen evolution cocatalyst (OEC) and semiconductor photoanode, boosting the photogenerated electron-hole separation and thus improving PEC activity. This state-ofthe-art OEC/Ni-N-4-O/BiVO4 photoanode exhibits a record high photo-current density of 6.0 mA cm(-2) at 1.23 V versus reversible hydrogen electrode (vs RHE), over approximately 3.97 times larger than that of BiVO4, achieving outstanding long-term photostability. From X- ray absorption fine structure analysis and density functional theory calculations, the enhanced PEC performance is attributed to the construction of single-atomic Ni-N-4-O moiety in OEC/BiVO4, facilitating the holes transfer, decreasing the free energy barriers, and accelerating the reaction kinetics. This work enables us to develop an effective pathway to design and fabricate efficient and stable photoanodes for feasible PEC water splitting application.
|
|
| 15. |
- Zhang, Yanting, et al.
(författare)
-
Two-Dimensional Defective Boron-Doped Niobic Acid Nanosheets for Robust Nitrogen Photofixation
- 2021
-
Ingår i: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 15:11, s. 17820-17830
-
Tidskriftsartikel (refereegranskat)abstract
- Direct nitrogen photofixation is a feasible solution toward sustainable production of ammonia under mild conditions. However, the generation of active sites for solar-dirven nitrogen fixation not only limits the fundamental understanding of the relationship among light absorption, charge transfer, and catalytic efficiency but also influences the photocatalytic activity. Herein, we report two-dimensional boron-doped niobic acid nanosheets with oxygen vacancies (B-V-o-HNbO3 NSs) for efficient N-2 photofixation in the absence of any scavengers and cocatalysts. Impressively, B-V-o-HNbO3 NS as a model catalyst achieves the enhanced ammonia evolution rate of 170 mu mol g(cat)(-1) h(-1) in pure water under visible-light irradiation. The doublet coupling representing (NH4+)-N-15 in an isotopic labeling experiment and in situ infrared spectra confirm the reliable ammonia generation. The experimental analysis and density functional theory (DFT) calculations indicate that the strong synergy of boron dopant and oxygen vacancy regulates band structure of niobic acid, facilitates photogenerated charge transfer, reduces free energy barriers, accelerates reaction kinetics, and promotes the high rates of ammonia evolution. This work provides a general strategy to design active photocatalysts toward solar N-2 conversion.
|
|
