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Spectral flow, Llarull's rigidity theorem in odd dimensions and its generalization

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Science China Mathematics 2024年第5期67卷 1103-1114页

作者： yihan li Guangxiang su Xiangsheng Wang Chern Institute of Mathematics&LPMC Nankai UniversityTianjin 300071China School of Mathematics Shandong UniversityJinan 250100China

For a compact spin Riemannian manifold(M,g^(TM))of dimension n such that the associated scalar curvature kT M verifies that k^(TM)≥n(n-1),Llarull’s rigidity theorem says that any area-decreasing smooth map f from M to the unit sphere Sn of nonzero degree is an *** this paper,we present a new proof of Llarull’s rigidity theorem in odd dimensions via a spectral flow *** approach also works for a generalization of Llarull’s theorem when the sphere Sn is replaced by an arbitrary smooth strictly convex closed hypersurface in Rn+*** results answer two questions by Gromov(2023).

关键词： Dirac operator scalar curvature spectral flow

A Two-layer Framework for Mitigating the Con-gestion of Urban Power Grids Based on Flexible Topology with Dynamic Thermal Rating

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Protection and Control of Modern Power Systems 2024年第4期9卷 83-95页

作者： yi su Jiashen Teh Qian Luo Kangmiao Tan Jiaying Yong the School of Automation and Electronic In-formation Xiangtan Universityxiangtan 411100China IEEE the School of Electrical and Electronic Engineering Universiti Sains Malaysia(USM)Penang 11800Malaysia the School of Computer Sciences Universiti Sains Malaysia(USM)Penang 11800Malaysia the Institute of Power Engineering College of EngineeringUniversiti Tenaga Nasional(UNITEN)Kajang 43000Malaysia

The urban power grid(UPG)combines transmission and distribution *** studies on UPG congestion mitigation have primarily focused on relieving local congestion while ignoring large-scale energy transfer with safety margins and load *** situation is expected to worsen with the proliferation of renewable energy and electric *** this paper,a two-layer congestion mitigation framework is proposed,one which considers the congestion of the UPG with flexible *** the upper-layer,the particle swarm optimization algorithm is employed to optimize the power supply distribution(PSD)of substation *** is known as the upper-layer *** lower-layer model recalculates the new PSD,known as the lower-layer PSD,based on the topology candidates.A candidate topology is at an optimum when the Euclidean distance mismatch between the upper-and lower-layer PSDs is the *** optimum topology is tested by standard power flow to ascertain its *** optimum transitioning sequence between the initial and optimum topologies is also determined by the two-layer framework to minimize voltage deviation and line overloading of the UPG considering dynamic thermal *** proposed framework is tested on a 56-node test *** show that the proposed framework can significantly reduce congestion,maintain safety margins,and determine the optimum transitioning sequence.

关键词： Congestion mitigation urban power grid two-layer framework transitioning sequence dynamic thermal rating

Self-propelled Leidenfrost droplets on femtosecond-laser-induced surface with periodic hydrophobicity gradient

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International Journal of Extreme Manufacturing 2024年第2期6卷 502-509页

作者： Bohong li Lan Jiang Xiaowei li Zhipeng Wang Peng yi Laser Micro/Nano Fabrication Laboratory School of Mechanical EngineeringBeijing Institute of TechnologyBeijingPeople’s Republic of China Beijing Institute of Technology Chongqing Innovation Center ChongqingPeople’s Republic of China Yangtze Delta Region Academy of Beijing Institute of Technology JiaxingPeople’s Republic of China

The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so *** Leidenfrost effect can be utilized to significantly reduce motion ***,the use of 3D structures limits the widespread application of self-propulsion based on Leidenfrost droplets in microelectromechanical *** manipulate Leidenfrost droplets,it is necessary to create 2D or quasi-2D *** this study,femtosecond laser is applied to fabricate a surface with periodic hydrophobicity gradient(SPHG),enabling directional self-propulsion of Leidenfrost *** field analysis within the Leidenfrost droplets reveals that the vapor layer between the droplets and the hot surface can be modulated by the SPHG,resulting in directional propulsion of the inner *** viscous force between the gas and liquid then drives the droplet to move.

关键词： self-propelled Leidenfrost droplets periodic hydrophobicity gradient femtosecond laser fabrication

Exploring changes of precipitation extremes under climate change through global variable-resolution modeling

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Science Bulletin 2024年第2期69卷 237-247页

作者： Wei sun Jian li Rucong Yu Nina li yi Zhang State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Institute of Tibetan Plateau Meteorology China Meteorological AdministrationChengdu 610072China Department of Atmospheric Science Yunnan UniversityKunming 650091China National Meteorological Center China Meteorological AdministrationBeijing 100081China 2035 Future Laboratory PIESAT Information Technology Co.Ltd.Beijing 100105China

Understanding the responses of precipitation extremes to global climate change remains limited owing to their poor representations in models and complicated interactions with multi-scale *** we take the record-breaking precipitation over China in 2021 as an example,and study its changes under three different climate scenarios through a developed pseudo-global-warming(PGW)experimental framework with 60-3 km variable-resolution global ensemble *** to the present climate,the precipitation extreme under a warmer(cooler)climate increased(decreased)in intensity,coverage,and total amount at a range of 24.3%-37.8%(18.7%-56.1%).With the help of the proposed PGW experimental framework,we further reveal the impacts of the multi-scale system interactions in climate change on the precipitation *** the warmer climate,large-scale water vapor transport converged from double typhoons and the subtropical high marched into central China,enhancing the convective energy and instability on the leading edge of the transport *** a result,the mesoscale convective system(Mcs)that directly contributed to the precipitation extreme became stronger than that in the present *** the contrary,the cooler climate displayed opposite changing characteristics relative to the warmer climate,ranging from the large-scale systems to local environments and to the *** summary,our study provides a promising approach to scientifically assess the response of precipitation extremes to climate change,making it feasible to perform ensemble simulations while investigating the multi-scale system interactions over the globe.

关键词： Precipitation extreme Climate change Pseudo-global-warming experiment Variable-resolution modeling Multi-scale system interaction

Solid-state synthesis and ion transport characteristics of the β-KSbF_(4) for all-solid-state fluoride-ion batteries

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Journal of Energy Chemistry 2024年第7期94卷 758-767页

作者： Jiali liu Huahui Zhao Jingcheng Xia lingguang yi Xiaoyi Chen Dongdu li Shuhan Ni Xinyi su yixuan Chen Min liu Xianyou Wang National Base for International Science&Technology Cooperation National Local Joint Engineering Laboratory for Key Materials of New Energy Storage BatteryHunan Province Key Laboratory of Electrochemical Energy Storage&ConversionSchool of ChemistryXiangtan UniversityXiangtan 411105HunanChina College of New Energy Ningbo University of TechnologyNingbo 315336ZhejiangChina

All-solid-state fluoride ion batteries(FIBs)have been recently considered as a post-lithium-ion battery system due to their high safety and high energy *** like all solid-state lithium batteries,the key to the development of FIBs lies in room-temperature electrolytes with high ionic conductivity.β-KSbF_(4) is a kind of promising solid-state electrolyte for FIBs owing to its rational ionic conductivity and relatively wide electrochemical stability window at room ***,the previous synthesis routes ofβ-KSbF_(4) required the use of highly toxic hydrofluoric acid and the ionic conductivity of as-prepared product needs to be further ***,the β-KSbF_(4) sample with an ionic conductivity of 1.04×10^(-4)s cm^(-1)(30°C)is synthesized through the simple solid-state *** order to account for the high ionic conductivity of the as-synthesizedβ-KSbF_(4),X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive X-ray spectroscopy(EDS)are used to characterize the physic-ochemical *** results show that the as-synthesizedβ-KSbF_(4) exhibits higher carrier concentra-tion of 1.0×10^(-6)S cm-Hz^(-1)K and hopping frequency of 1.31×10^(6)Hz at 30°C due to the formation of the fluorine ***,the hopping frequency shows the same trend as the changes of ionic conductivity with the changes of temperature,while the carrier concentration is found to be almost *** two different trends indicate the hopping frequency is mainly responsible for the ionic conduc-tion behavior withinβ-KSbF_(4).Furthermore,the all-solid-state FIBs,in which Ag and Pb+PbF_(2) are adopted as cathode and anode,andβ-KSbF_(4) as fluoride ion conductor,are capable of reversible charge and *** assembled FIBs show a discharge capacity of 108.4 mA h g^(-1) at 1st cycle and 74.2 mA h g^(-1) at 50th *** on an examination of the capacity decay mechanism,it has been found that deterioration of the electrolyte/electrode int

关键词： Solid-state electrolyte Carrier concentration Hopping frequency β-KSbF_(4) All-solid-state fluoride ion batteries

Discovery of CCDC188 gene as a novel genetic target for human acephalic spermatozoa syndrome

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Protein & Cell 2024年第9期15卷 704-709页

作者： Jing Wang Hui-Juan Jin yi Lu Zi-Han Wang Teng-Yan li Lan Xia Hong-Jun li Bin-Bin Wang su-Ren Chen Department of Medical Genetics and Developmental Biology School of Basic Medical SciencesCapital Medical UniversityBeijing 100069China Key Laboratory of Cell Proliferation and Regulation Biology Ministry of EducationDepartment of BiologyCollege of Life SciencesBeijing Normal UniversityBeijing 100875China Graduate School Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100005China Department of Urology Peking Union Medical College HospitalBeijing 100005China Center for Genetics National Research Institute of Family PlanningBeijing 100081China NHC Key Laboratory of Reproductive Health Engineering Technology Research(NRIFP) Beijing 100081China

Dear Editor,Male infertility is a widespread health problem and affects approximately 6%–8%of the male population(Jiao et al.,2021).Acephalic spermatozoa syndrome(ASS),a rare but severe type of teratozoospermia,is ch... 详细信息

关键词： al. infertility finally

Design of weak current measurement system and research on temperature impact

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Nuclear Science and Techniques 2024年第4期35卷 46-56页

作者： Chu-Xiang Zhao San-Gang li Rong-Rong su li Yang Ming-Zhe liu Qing-Yue Xue Shan liao Zhi Zhou Qing-Shan Tan Xian-Guo Tuo yi Cheng College of Nuclear Technology and Automation Engineering Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China University of Science and Technology of China Hefei 230026China School of Physics and Electronic Engineering Sichuan University of Science and EngineeringZigong 643000China

A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ionization *** system incorporates a second-order low-pass filter circuit and the Kalman filtering algorithm to effectively filter out noise and minimize interference in the measurement *** conducted under normal temperature conditions has demonstrated the system's high precision ***,it was observed that temperature variations can affect the measurement *** were collected across temperatures ranging from -20 to 70℃,and a temperature correction model was established through linear regression fitting to address this *** feasibility of the temperature correction model was confirmed at temperatures of -5 and 40℃,where relative errors remained below 0.1% after applying the temperature *** research indicates that the designed measurement system exhibits excellent temperature adaptability and high precision,making it particularly suitable for measuring weak currents.

关键词： Weak current measurement system Neutron ionization chamber Kalman filter algorithm Temperature correction model

superconducting,Topological,and Transport Properties of Kagome Metals CsTi_(3)Bi_(5)and RbTi_(3)Bi_(5)

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Research 2024年第2期2023卷 753-762页

作者： Xin-Wei yi Zheng-Wei liao Jing-Yang You Bo Gu Gang su School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Physics Faculty of ScienceNational University of Singapore117551Singapore Kavli Institute for Theoretical Sciences and CAS Center for Excellence in Topological Quantum ComputationUniversity of Chinese Academy of SciencesBeijing 100190China

The recently discovered ATi_(3)Bi_(5)(A=Cs,Rb)exhibit intriguing quantum phenomena including superconductivity,electronic nematicity,and abundant topological ***_(3)Bi_(5)present promising platforms for studying kagome superconductivity,band topology,and charge orders in parallel with *** this work,we comprehensively analyze various properties of ATi_(3)Bi_(5)covering superconductivity under pressure and doping,band topology under pressure,thermal conductivity,heat capacity,electrical resistance,and spin Hall conductivity(SHC)using first-principles *** superconducting transition temperature(Tc)of CsTi_(3)Bi_(5)and RbTi_(3)Bi_(5)at ambient pressure are about 1.85 and 1.92 *** subject to pressure,Tc of CsTi_(3)Bi_(5)exhibits a special valley and dome shape,which arises from quasi-two-dimensional compression to three-dimensional isotropic compression within the context of an overall decreasing ***,Tc of RbTi_(3)Bi_(5)can be effectively enhanced up to 3.09 K by tuning the kagome van Hove singularities(VHSs)and flat band through *** can also induce abundant topological surface states at the Fermi energy(EF)and tune VHSs across ***,our transport calculations are in excellent agreement with recent experiments,confirming the absence of charge density ***,SHC of CsTi_(3)Bi_(5)can reach up to 226h·(e·Ω·cm)^(-1)at *** work provides a timely and detailed analysis of the rich physical properties for ATi_(3)Bi_(5),offering valuable insights for further experimental verifications and investigations in this field.

关键词： doping superconductivity conductivity

Synergistic precipitant powered self-assembly of papain for cross-linked enzyme crystals preparation

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Particuology 2024年第2期85卷 102-112页

作者： Qi Hao Pan Guo Honghai Wang Min su Chunli li Yuqi Hu Weiyi su School of Chemical Engineering and Technology Hebei University of TechnologyTianjin300130China National-Local Joint Engineering Laboratory for Energy Conservation of Chemical Process Integration and Resources Utilization Tianjin300130China

In this study,we prepared cross-linked enzyme crystals(CLECs)of papain to further broaden the application of the enzyme with high activity in extreme ***,papain crystals were successfully obtained based on the micro-batch,batch,and expanded batch crystallization ***,ammonium sulfate and polyethylene glycol 6000(PEG6000)were synergistically used as the precipitants,while L-cysteine was applied to enhance the activity of ***,the interaction between L-cysteine and papain was modeled by molecular docking *** was found that L-cysteine could form a hydrogen bond with aspartic acid residue(Asp)at site 158,and the electrostatic attraction with lysine residue(Lys)at site 156 was also quite *** the enzyme crystals were cross-linked by glutaraldehyde at optimized *** papain CLECs were identified by various methods,and it was found that the thermal stability and enzymatic activity both increased compared to the raw *** importantly,it could be applied at more rigorous conditions,for example,pH of 4.

关键词： Papain Cross-linked enzyme crystals L-cysteine Molecular docking Crystallization