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Journal of Hydrodynamics 2024年第2期36卷 219-231页

作者： Chen geng Zhao-hui Qian Ke-xin Zheng Wei-xiang Ye Xian-wu Luo State Key Laboratory of Hydroscience cand Engineering Deparment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China

In the present paper,the unsteady cavitating turbulent flow over the twisted NACA66 hydrofoil is investigated based on an modified shear stress transfer k-ωpartially averaged Navier-Stokes(MSST PANS)model,i.e.,new MSST PANS(NMSST PANS)model,where the production term of kinetic energy in the turbulence model is modified with *** with the experimental data,cavitation evolution and its characteristic frequency are satisfactorily predicted by the proposed NMSST PANS *** is revealed that the interaction among the main flow,the reentrant jets,and sheet cavitation causes the formation of the primary shedding cavity near the mid-span and the secondary shedding cavity at each side of the twisted hydrofoil,and further induces the remarkable pressure gradient around shedding *** with the development of the primary and the secondary shedding cavities,the great pressure gradient associated with large cavity volume variation promotes the vortical flow generation and the spatial deformation of vortex structure during cavitation evolution,and results in the primary and the secondary U-type ***,dynamic mode decomposition(DMD)analysis is utilized to confirm the interaction among the main flow,the main reentrant jet and two side reentrant jets,and *** results indicate that the proposed NMSST PANS model is suitable to simulate the complicated cavitating turbulent flow for various engineering applications.

关键词： Cavitating turbulent flow partially averaged Navier-Stokes(PANS)model hydrofoil numerical simulation

AHLNet:Adaptive Multihead Structure and Lightweight Feature Pyramid Network for Detection of Live Working in Substations

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Machine Intelligence Research 2024年第5期21卷 983-992页

作者： Mengle Peng Xiaoyong Jiang Langyue Huang Zhongyi Li Haiteng Wu Xiaotang geng Zhejiang University of Science and Technology Hangzhou310023China Zhejiang Key Laboratory of Intelligent Operation and Maintenance Robot Hangzhou311100China

With the increasing demand for power in society,there is much live equipment in substations,and the safety and standardization of live working of workers are facing *** at these problems of scene complexity and object diversity in the real-time detection of the live working safety of substation workers,an adaptive multihead structure and lightweight feature pyramid-based network(AHLNet)is proposed in this study,which is based on ***,we take AH-Darknet53 as the backbone network of YOLOV3,which can introduce an adaptive multihead(AMH)structure,reduce the number of network parameters,and improve the feature extraction ability of the backbone ***,to reduce the number of convolution layers of the deeper feature map,a lightweight feature pyramid network(LFPN)is proposed,which can perform feature fusion in advance to alleviate the problem of feature imbalance and gradient ***,the proposed AHLNet is evaluated on the datasets of 16 categories of substation safety operation scenarios,and the average prediction accuracy MAP_(50)reaches 82.10%.Compared with YOLOV3,MAP_(50)is increased by 2.43%,and the number of parameters is 90 M,which is only 38%of the number of parameters of *** addition,the detection speed is basically the same as that of YOLOV3,which can meet the real-time and accurate detection requirements for the safe operation of substation staff.

关键词： Adaptive multihead structure lightweight feature pyramid substation feature imbalance multiobject detection

Study on the dynamic mechanical properties of winding-block axial structure considering short circuit strain rate effect

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High Voltage 2024年第2期9卷 380-390页

作者： Xinyu Wang Ping Wang Jianghai geng Zikang Zhang Fangcheng Lü Shuguo Gao Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense North China Electric Power UniversityBaodingChina State Grid Hebei Electric Power Research Institute ShijiazhuangChina

Transformers may suffer multiple short-circuit impacts during long-term operation,and axial instability is one of the typical types of serious accidents caused by short-circuit *** axial instability form of the winding-block structure is analysed,and the dynamic solution of the winding short-circuit electromagnetic force is obtained by estab-lishing the three-dimensional magnetic-circuit-force multi-physical field coupling simulation *** influence of strain rate on the cushion block constitutive equation is corrected,and the modified model is verified by short-circuit impact test and quasi-static *** research results show that for 110 kV 31.5 MVA transformers,the maximum electromagnetic axial resultant force of winding is 363.16 kN,and the ultimate tilt force is 1214.2 *** pre-tightening force configuration is accordingly recom-mended to range from 363.16 to 608.28 kN,which is narrowed by 18.49%compared with the static calculation method;Meanwhile,adding a logarithmic strain rate correction term to the classical constitutive equation of the cushion block can achieve a good correction of the stress-strain relationship with the coefficient of determination above 0.99,and the cushion block has a larger elastic modulus under high strain rate *** research results provide an important theoretical reference for the axial stability structure of transformers.

关键词： axial correction structure

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地理科学的学科体系构建与内涵

科学通报 2021年第2期66卷 153-161页

作者：熊巨华王佳张晴耿豪鹏官冬杰史云飞李飞张新林王天富国家自然科学基金委员会地球科学部北京100085

完善的理论体系、深厚的人才队伍和先进的技术手段是支撑一个学科良性发展的3个必要条件.自1986年国家自然科学基金委员会成立以来,地理学历经3个阶段多次的申请代码调整,其根本原因在于适应学科外延的快速拓展与研究内涵的不断深化,目... 详细信息

完善的理论体系、深厚的人才队伍和先进的技术手段是支撑一个学科良性发展的3个必要条件.自1986年国家自然科学基金委员会成立以来,地理学历经3个阶段多次的申请代码调整,其根本原因在于适应学科外延的快速拓展与研究内涵的不断深化,目的在于引导和扶持学科发展.依据目前学科知识体系的逻辑结构、演化规律和发展趋势,为持续促进学科前沿发展,巩固人才队伍,并引导学科服务国家需求,2021年开始国家自然科学基金申请指南中地理学将正式更名为“地理科学”,共包括17个二级申请代码.

关键词：学科服务国家自然科学基金学科体系构建学科知识体系人才队伍学科前沿逻辑结构申请代码

Recent progress in single crystal perovskite X-ray detectors

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Science China(Information Sciences) 2024年第3期67卷 5-19页

作者： Xiao LIU Jun REN Yu-Ang CHEN Xiangshun geng Dan XIE Tian-Ling REN School of Integrated Circuits Tsinghua University Beijing National Research Center for Information Science and Technology (BNRist)

Perovskites have attracted extensive attention as radiation detection material due to their long carrier diffusion length and lifetime, high absorption coefficient, and flexible manufacturing process. Compared with polycrystalline structures, single crystal perovskites improve the performance of optoelectronic devices due to their low defect state density, better photoelectric characteristics, and chemical ***, we review the recent progress of single crystal perovskite X-ray detectors. First, we briefly introduced the basic concepts, detection mechanisms, figure of merits of perovskite X-ray detectors, and the preparation methods of single crystal perovskites. Then, we summarized the significant advancements in single crystal perovskite X-ray detectors in recent times. Finally, we discussed the critical challenges and some practicable solutions for developing high-performance X-ray detectors.

关键词： single crystal perovskites carrier transport radiation detection X-ray detectors X-ray imaging

Nanostructured AlFeO_(3) thin films as a novel photoanode for photoelectrochemical water splitting

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Nano Research 2024年第3期17卷 1075-1085页

作者： Xin Sun Min Wang Qi geng Shuailin Chen Xiaojun Lv Xunlei Ding Meicheng Li State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources School of New EnergyNorth China Electric Power UniversityBeijing 102206China School of Mathematics and Physics North China Electric Power UniversityBeijing 102206China

The earth-abundant and robust aluminum ferrite,AlFeO_(3)(AFO),is mainly studied in the context of ***,we demonstrate that AFO can be used as a stable solar absorber in photoelectrochemical cells for solar water splitting,exhibiting attractive *** is the first report on the photoelectrochemical activity of *** thin-film photoelectrodes prepared by solution-processing methods are composed of vertically oriented thin nanosheets,featuring the rhombohedral symmetry(R3c)and n-type *** as-prepared AFO photoanodes generate a photocurrent density of+0.78 mA·cm^(-2) at 1.23 V *** hydrogen electrode(RHE)with the photocurrent _(onset) potential(U_(onset))close to the flat band potential of 0.5 V *** in the presence of hole ***,the U_(onset) of AFO for solar water splitting coincides with the flat band potential as well,which is rare in n-type inorganic *** also report other properties of AFO associated with photoelectrochemical *** films exhibit a band gap energy of 2.31 eV and positive band edges with low ***,the carrier lifetimes in AFO films are up to millisecond timescales under the mediation of defect *** on the photoelectrochemical behavior and optoelectronic properties,we believe that AFO has great potential for application in photoelectrochemical cells.

关键词： AlFeO_(3) photoanode nanosheets photoelectrochemistry onset potential

An integrable generalization of the Fokas–Lenells equation:Darboux transformation, reduction and explicit soliton solutions

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Chinese Physics B 2024年第7期33卷 117-124页

作者：魏姣耿献国王鑫 School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China School of Mathematics and Information Science Zhongyuan University of TechnologyZhengzhou 450007China

Under investigation is an integrable generalization of the Fokas–Lenells equation, which can be derived from the negative power flow of a 2 × 2 matrix spectral problem with three potentials. Based on the gauge transformation of the matrix spectral problem, one kind of Darboux transformation with multi-parameters for the three-component coupled Fokas–Lenells system is constructed. As a reduction, the N-fold Darboux transformation for the generalized Fokas–Lenells equation is obtained, from which the N-soliton solution in a compact Vandermonde-like determinant form is given. Particularly,the explicit one-and two-soliton solutions are presented and their dynamical behaviors are shown graphically.

关键词： Darboux transformation soliton solutions generalized Fokas–Lenells equation

Distinct clinical profiles and mutation landscapes of gliomas originating from the neocortex,mesocortex,and cerebellum

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Genes & Diseases 2024年第1期11卷 53-56页

作者： Ye Cheng Lei Zhang Xiaolong Wu Hiroaki Wakimoto Haoming geng Yukui Wei geng Xu Xinru Xiao Jie Bai Yaming Wang Zeliang Hu Leiming Wang Qingtang Lian Department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijing 100053China Brain Tumor Research Center Massachusetts General HospitalDepartment of NeurosurgeryHarvard Medical SchoolBostonMA02134USA Department of Pathology Xuanwu HospitalCapital Medical UniversityBeijing 100053China

Gliomas originating from anatomically and developmentally distinct brain regions have different clinical ***,the molecular landscape underlying this difference remains *** analyzed key molecular mutations via sequencing and correlated them with clinical characteristics in 180 adult patients with gliomas originating from the neocortex,mesocortex,and *** of cerebellar origin had significantly longer survival than those of supratentorial origin,consistent with higher rates of mutation in key genes associated with supratentorial gliomas.

关键词： clinical cortex glioma

New signature of low mass Z'in J/ψdecays

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Chinese Physics C 2024年第8期48卷 1-5页

作者： Chao-Qiang geng Chia-Wei Liu Jiabao Zhang School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China Tsung-Dao Lee Institute&School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Institute of Theoretical Physics University of Chinese Academy of SciencesBeijing 100190China

We explored a new approach to search for a low-mass Z′particle through J/ψdecays by identifying its existence through parity-violating phenomena in the isospin-violating final states ofΛΣ¯^(0)and the corresponding charge conjugated states ofΛΣ¯^(0).Our investigation centered on a generation-independent and leptophobic Z′with mass below 10 *** the present experimental conditions at Beijing Spectrometer III(BESIII)and the anticipated opportunities at the Super Tau Charm Factory(STCF),we conducted Monte-Carlo simulations to predict possible events at both ***,we foresee a substantial enhancement in the precision of the lower limit estimation ofαNP as well as a reduction in statistical uncertainty with upcoming STCF ***,it is essential to highlight that a null result in the measurement ofαNP would impose stringent constraints,requiring the Z′−q−q couplings to be in the order of 10^(−2).

关键词： Z′ parity violation J/ψ

High performance photodegradation resistant PVA@TiO_(2)/carboxyl-PES self-healing reactive ultrafiltration membrane

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Chinese Journal of Chemical Engineering 2024年第2期66卷 31-39页

作者： Yu Liang Yuanfang Fan Zhongmin Su Mingxin Huo Xia Yang Hongliang Huo Chi Wang Zhi geng College of Environment Engineering Research Center of Low-Carbon Treatment and Green Development of Polluted Water in Northeast ChinaMinistry of EducationNortheast Normal UniversityChangchun 130117China School of Science Hainan UniversityHaikou 570225China

The occurrence of ultrafiltration(UF)membrane fouling frequently hampers the sustainable advancement of UF *** self-cleaning UF membranes can effectively alleviate the problem of membrane ***,the self-cleaning process may accelerate membrane *** these concerns,we present an innovative design concept for composite self-healing materials based on self-cleaning UF *** begin,TiO_(2)nanoparticles were incorporated into the polymer molecular structure via molecular design,resulting in the synthesis of TiO_(2)/carboxyl-polyether sulfone(PES)hybrid ***,the nonsolvent-induced phase inversion technique was employed to prepare a novel of UF ***,a polyvinyl alcohol(PVA)hydrogel coating was applied to the hybrid UF membrane surface to create PVA@TiO_(2)/carboxyl-PES self-healing reactive UF *** establishing a covalent bond,the TiO_(2)nanoparticles were effectively and uniformly dispersed within the UF membrane,leading to exceptional self-cleaning ***,the water-absorbing and swelling properties of PVA hydrogel,along with its capacity to form hydrogen bonds with water molecules,resulted in UF membranes with improved hydrophilicity and active self-healing *** results demonstrated that the water contact angle of PVA@5%TiO_(2)/carboxyl-PES UF membrane was 43.1°.Following a 1-h exposure to simulated solar exposure,the water flux recovery ratio increased from 48.16%to 81.03%.Moreover,even after undergoing five cycles of 12-h simulated sunlight exposure,the UF membranes exhibited a consistent retention rate of over 97%,thus fully demonstrating their exceptional self-cleaning,antifouling,and selfhealing *** anticipate that the self-healing reactive UF membrane system will serve as a pioneering and comprehensive solution for the self-cleaning antifouling challenges encountered in UF membranes while also effectively mitigating the aging effects of reactive

关键词： Ultrafiltration membrane Self-cleaning Self-healing Poly(aryl ether sulfone)