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Persistent Variations in the East Asian Trough from March to April and the Possible Mechanism

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Advances in Atmospheric Sciences 2024年第4期41卷 737-753,I0002-I0004页

作者： shui YU Jianqi SUN Nansen-Zhu International Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The East Asian trough(EAT)profoundly influences the East Asian spring *** this study,the relationship of the EATs among the three spring months is *** analysis shows that the variation in March EAT is closely related to that of April *** empirical orthogonal function(EEOF)analysis also confirms the co-variation of the March and April *** positive/negative EEOF1 features the persistent strengthened/weakened EAT from March to *** investigation indicates that the variations in EEOF1 are related to a dipole sea surface temperature(SST)pattern over the North Atlantic and the SST anomaly over the tropical Indian *** dipole SST pattern over the North Atlantic,with one center east of Newfoundland Island and another east of Bermuda,could trigger a Rossby wave train to influence the EAT in March−*** SST anomaly over the tropical Indian Ocean can change the Walker circulation and influence the atmospheric circulation over the tropical western Pacific,subsequently impacting the southern part of the EAT in March−*** the SST factors,the Northeast Asian snow cover could change the regional thermal conditions and lead to persistent EAT anomalies from March to *** three impact factors are generally independent of each other,jointly explaining large variations in the EAT ***,the signals of the three factors could be traced back to February,consequently providing a potential prediction source for the EAT variation in March and April.

关键词： spring East Asian trough sea surface temperature snow cover

Fluid-structure interaction simulation for multi-body flexible morphing structures

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Chinese Journal of Aeronautics 2024年第2期37卷 137-147页

作者： Wenzhi GUO Yongtao shui Lu NIE Gang CHEN State Key Laboratory of Strength and Vibration for Mechanic Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an 710049China China Academy of Launch Vehicle Technology Beijing 100076China China Academy of Aerospace Science and Innovation Beijing 100086China Shannxi Key Laboratory of Service Environment and Control for Flight Vehicles Xi’an Jiaotong UniversityXi’an 710049China

The multi-body flexible morphing airfoil can improve the aerodynamic characteristics based on different flight missions *** researches have focused on the unsteady aerodynamic characteristics of flexible wings under passive ***,the unsteady aerodynamic characteristics with the fluid-structure interaction effects in the multi-body active actuation process of morphing airfoil deserve further *** this paper,a fluid-structure coupled simulation method for multi-body flexible morphing airfoil with active actuation subsystem was investigated,and the aerodynamic characteristics during deformation were compared with different skin flexibility,flow field environment,actuation mode and actuation *** numerical results show that for the steady aerodynamic,the skin flexibility can improve the stability *** the unsteady process,the change trend of the transient lift coefficient and pitching moment are consistent with those of the active drive characteristics,while the instantaneous lift-drag ratio coefficient is greatly affected by the driving mode and can be improved by increasing the driving duration.

关键词： Fluid-structure interaction Multi-body dynamics modeling Flexible structures Aerodynamics Morphing wings

Emerging roles and therapeutic potentials of sphingolipids in pathophysiology:emphasis on fatty acyl heterogeneity

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Journal of Genetics and Genomics 2024年第3期51卷 268-278页

作者： Jinming Mu Sin Man Lam Guanghou shui State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China Lipidall Technologies Company Limited ChangzhouJiangsu 213000China

Sphingolipids not only exert structural roles in cellular membranes,but also act as signaling molecules in various physiological and pathological processes.A myriad of studies have shown that abnormal levels of sphingolipids and their metabolic enzymes are associated with a variety of human ***,blood sphingolipids can also be used as biomarkers for disease *** review summarizes the biosynthesis,metabolism,and pathological roles of sphingolipids,with emphasis on the biosynthesis of ceramide,the precursor for the biosynthesis of complex sphingolipids with different fatty acyl *** possibility of using sphingolipids for disease prediction,diagnosis,and treatment is also *** endogenous ceramides and complex sphingolipids along with their specific fatty acyl chain to promote future drug development will also be discussed.

关键词： Sphingolipids Ceramide Therapeutic targets Microdomain Biomarker

A simple path to ambient temperature ionic H^(-)superconductors

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Science China Chemistry 2024年第1期67卷 321-322页

作者： Bingru Liu Shiyuan Liu Jianglan shui School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Hydride ion(H^(-))has high polarizability(α_(H^(-))=10.17A^(3))and high redox potential(H^(-)/H_(2):-2.3 V),and therefore is an attractive energy carrier[1,2].The H^(-)superconductors play a crucial role in the devel... 详细信息

关键词： attractive ambient superconductors

Strong invariance principle for a counterbalanced random walk

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 370-380页

作者： TAN Hui-qun HU Zhi-shui DONG Liang International Institute of Finance School of ManagementUniversity of Science and Technology of ChinaHefei 230026China Center for Basic Teaching and Experiment Nanjing University of Science and TechnologyJiangyin 214443China

We study a counterbalanced random walkS_(n)=X_(1)+…+X_(n),which is a discrete time non-Markovian process andX_(n) are given recursively as *** n≥2,X_(n) is a new independent sample from some fixed law̸=0 with a fixed probability p,andX_(n)=−X_(v(n))with probability 1−p,where v(n)is a uniform random variable on{1;…;n−1}.We apply martingale method to obtain a strong invariance principle forS_(n).

关键词： random walk martingale invariance principle

Identification of the optimal doping position of hetero-atoms in chalcogen-doped Fe-N-C catalysts for oxygen reduction reaction

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Particuology 2024年第6期89卷 99-108页

作者： Weihao Liu Huanhuan He Qingtao Liu Xin Wan Jianglan shui School of Materials Science and Engineering Beihang UniversityBeijing100191China School of Space and Environment Beihang UniversityBeijing102206China Tianmushan Laboratory Hangzhou310023China

The excellent oxygen reduction reaction(ORR)activity of Fe–N–C catalysts in acidic media makes them potential for low-cost proton exchange membrane fuel *** recent years,it has been shown that heteroatoms(B,O,S,P,Cl,F,etc.)can be used as electron-withdrawing groups to modulate the planar structure and electron distribution of the Fe–Nx active sites to achieve simultaneous improvement of catalytic activity and ***,the optimal location of the heteroatoms remains ***,taking chalcogen heteroatoms(S and Se)as an example,we control the doping positions and investigate their effect on the ORR performance of the Fe–N–C *** first coordination shell of the iron single atom is identified as the optimal doping *** optimized catalysts Fe–N_(3)Se_(1)/NC and Fe–N_(3)Se_(1)/NC demonstrate improved activity and stability in both half cells and fuel *** work provides insights into the enhancement mechanism of heteroatom doping in single-atom catalysts.

关键词： Oxygen reduction reaction Fe-N-C catalysts Hetero-atom doping Doping position Enhancement mechanism

Meta label associated loss for fine-grained visual recognition

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Science China(Information Sciences) 2024年第6期67卷 230-247页

作者： Yanchao LI Fu XIAO Hao LI Qun LI shui YU School of Computer Science Nanjing University of Posts and Telecommunications School of Network Engineering Zhoukou Normal University School of Computer Science University of Technology Sydney

Recently, intensive attempts have been made to design robust models for fine-grained visual recognition, most notably are the impressive gains for training with noisy labels by incorporating a reweighting strategy into a meta-learning framework. However, it is limited to up or downweighting the contribution of an instance for label reweighting approaches in the learning process. To solve this issue, a novel noise-tolerant method with auxiliary web data is proposed. Specifically, first, the associations made from embeddings of well-labeled data with those of web data and back at the same class are measured. Next, its association probability is employed as a weighting fusion strategy into angular margin-based loss, which makes the trained model robust to noisy datasets. To reduce the influence of the gap between the well-labeled and noisy web data, a bridge schema is proposed via the corresponding loss that encourages the learned embeddings to be coherent. Lastly, the formulation is encapsulated into the meta-learning framework, which can reduce the overfitting of models and learn the network parameters to be noise-tolerant. Extensive experiments are performed on benchmark datasets, and the results clearly show the superiority of the proposed method over existing state-of-the-art approaches.

关键词： label associated loss weighting noisy samples fine-grained visual recognition noise-tolerant learning meta-learning

Boosting the Oxygen Reduction Performance of Fe-N-C Catalyst Using Zeolite as an Oxygen Reservoir

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Transactions of Tianjin University 2024年第5期30卷 428-435页

作者： Weihao Liu Qingtao Liu Xin Wan Jianglan shui School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Space and Environment Beihang UniversityBeijing 102206China Tianmushan Laboratory Hangzhou 311115China

Non-precious metal electrocatalysts(such as Fe-N-C materials) for the oxygen(O_(2)) reduction reaction demand a high catalyst loading in fuel cell devices to achieve workable performance. However, the extremely low solubility of O_(2) in water creates severe mass transport resistance in the thick catalyst layer of Fe-N-C catalysts. Here, we introduce silicalite-1 nanocrystals with hydrophobic cavities as sustainable O_(2) reservoirs to overcome the mass transport issue of Fe-N-C catalysts. The extra O_(2) supply to the adjacent catalysts significantly alleviated the negative effects of the severe mass transport resistance. The hybrid catalyst(Fe-N-C@silicalite-1) achieved a higher limiting current density than Fe-N-C in the half-cell test. In the H_(2)-O_(2) and H_2-air proton exchange membrane fuel cells, Fe-N-C@silicalite-1 exhibited a 16.3% and 20.2% increase in peak power density compared with Fe-N-C, respectively. The O_(2)-concentrating additive provides an effective approach for improving the mass transport imposed by the low solubility of O_(2) in water.

关键词： Oxygen reduction reaction Fuel cell Fe-N-C catalyst Oxygen reservoir Mass transport

Translating bacteriophage-derived depolymerases into antibacterial therapeutics:Challenges and prospects

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Acta Pharmaceutica Sinica B 2024年第1期14卷 155-169页

作者： Honglan Wang Yannan Liu Changqing Bai Sharon shui Yee Leung School of Pharmacy the Chinese University of Hong KongHong Kong SARChina Emergency Medicine Clinical Research Center Beijing Chao-Yang HospitalCapital Medical UniversityBeijing 100020China Department of Respiratory Shenzhen University General HospitalShenzhen University Clinical Medical AcademyGuangdong 518055China

Predatory bacteriophages have evolved a vast array of depolymerases for bacteria capture and *** depolymerases are enzymes responsible for degrading diverse bacterial surface *** are exploited as antibiofilm agents and antimicrobial adjuvants while rarely inducing bacterial resistance,making them an invaluable asset in the era of antibiotic *** depolymerases have been investigated preclinically,with evidence indicating that depolymerases with appropriate dose regimens can safely and effectively combat different multidrug-resistant pathogens in animal infection ***,some formulation approaches have been developed for improved stability and activity of ***,depolymerase formulation is limited to liquid dosage form and remains in its infancy,posing a significant hurdle to their clinical translation,compounded by challenges in their applicability and *** development must address these obstacles for clinical ***,after unravelling the history,diversity,and therapeutic use of depolymerases,we summarized the preclinical efficacy and existing formulation findings of recombinant ***,the challenges and perspectives of depolymerases as therapeutics for humans were assessed to provide insights for their further development.

关键词： Phage-derived polysaccharide depolymerases Bacteriophage proteins Bacterial capsules Polysaccharide capsules Antibiotic resistance Biofilms Antibacterial therapy Antimicrobial adjuvants Combination treatment