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New γ-Ray Sources Identified in All-sky Surveys Based on Fermipy's Advanced Algorithm

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Research in Astronomy and Astrophysics 2024年第10期24卷 81-91页

作者： Yunchuan Xiang peng Feng Xiaofei Lan School of Physics and Astronomy China West Normal UniversityNanchong 637009China Department of Astronomy Yunnan Universityand Key Laboratory of Astroparticle Physics of Yunnan ProvinceKunming 650091China

We employ an efficient method for identifying γ-ray sources across the entire sky,leveraging advanced algorithms from Fermipy,and cleverly utilizing the Galactic diffuse background emission model to partition the entire sky into72 regions,thereby greatly enhancing the efficiency of discovering new sources throughout the sky through multithreaded parallel *** confirming the reliability of the new method,we applied it for the first time to analyze data from the Fermi Large Area Telescope(Fermi-LAT)encompassing approximately 15.41 yr of all-sky *** this analysis,we successfully identified 1379 new sources with significance levels exceeding 4σ,of which 497 sources exhibited higher significance levels exceeding 5σ.Subsequently,we performed a systematic analysis of the spatial extension,spectra,and light variation characteristics of these newly identified *** identified 21 extended sources and 23 sources exhibiting spectral curvature above 10 ***,we identified 44 variable sources above 1 GeV.

关键词： gamma-rays:diffuse background methods:data analysis catalogs gamma-rays:general

Dynamic kinetic stereodivergent transformations of propargylic ammonium salts via dual nickel and copper catalysis

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Chinese Chemical Letters 2024年第8期35卷 265-269页

作者： Ruilong Geng Lingzi peng Chang Guo Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of ChinaHefei 230026China

The dynamic kinetic asymmetric transformation of racemic propargylic ammonium salts with prochiral aldimine esters through a stereodivergent propargylation is catalyzed by dual nickel and copper ***,a diverse range of optically activeα-quaternary amino esters were produced via C-N bond cleavage with high reaction efficiency and stereoselectivity(up to>99%ee).By selection of the appropriate pair-wise combination of catalyst configurational isomers,all four possible stereoisomers of the corresponding propargylation products are obtained in high yields with excellent regio-,diastereo-,and enantioselectiv-ities.

关键词： Stereodivergent propargylation Dual catalysis C-N bond cleavage Azaomethine ylides Internal propargylic ammonium salts Excellent stereoselectivity

Local Scour Mechanisms and Prediction Methods Around Offshore Wind Turbine Foundations:Insights and Future Directions

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Journal of Ocean University of China 2024年第5期23卷 1248-1262页

作者： YANG Qi HU Ruigeng YU peng ZHANG peng XU Zhongqian XU Mengzhen State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing 100084China Sinopec Petroleum Engineering Corporation Dongying 257100China Key Laboratory of Geological Safety of Coastal Urban Underground Space Ministry of Natural ResourcesQingdao Geo-Engineering Surveying InstituteQingdao 266101China Qingdao Qingzi Engineering Consulting Co. Ltd.Qingdao 266061China Qingdao Water Affairs Development Service Center Qingdao 266033China

Local scour around offshore wind turbine foundations presents a considerable challenge due to its potential influence on structural stability,driven by hydrodynamic *** research has made strides in comprehending scouring mechanisms,notable complexities persist,specifically with newer foundation *** these limitations is vital for advancing our understanding of scour mechanisms and for improving mitigation strategies in offshore wind energy *** review synthesizes current findings on local scour across various offshore foundations,encompassing field observations,data-driven approaches,turbulence-sediment interactions,scour evolution processes,influencing factors,and numerical model *** objective is to enrich our understanding of local scour *** addition,future research directions are outlined,including the development of robust arti-ficial intelligence models for accurate predictions,the exploration of vortex structure characteristics,and the refinement of numerical models to strengthen prediction capabilities while minimizing computational efforts.

关键词： local scour offshore wind turbine foundations wave-current actions sediment transport multiscale vortices numerical modeling

Paracrine function amplifies pro-tumor electrochemical signal within neuron-glioma synapses

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Science China(Life Sciences) 2024年第6期67卷 1318-1320页

作者： Yan Hu Peishan Hu Xiaozhong peng Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE State Key Laboratory of BiotherapyWest China Second University HospitalSichuan UniversityChengdu 610041China Guangdong Institute of Gastroenterology Department of General SurgeryGuangdong Provincial Key Laboratory of Colorectal and Pelvic Floor DiseasesThe Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhou 510655China Department of Molecular Biology and Biochemistry Institute of Basic Medical SciencesMedical Primate Research CenterNeuroscience CenterChinese Academy of Medical SciencesSchool of Basic Medicine Peking Union Medical CollegeBeijing 100730China State Key Laboratory of Respiratory Health and Multimorbidity Institute of Basic Medical Sciences Chinese Academy of Medical SciencesSchool of Basic Medicine Peking Union Medical CollegeBeijing 100730China Institute of Laboratory Animal Science Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China

Neuronal activity plays a pivotal role in various physiological processes,including tissue development,homeostasis,and *** in recent years have improved our understanding of neuronal activity in brain cancers,such as glioblastoma(GBM)and diffuse midline gliomas(DMG),which are among the most prevalent and lethal cancers affecting children and ***,the neurons regulate brain cancers via two routes.

关键词： glioma homeostasis function

Thyristor-inserted MMC Sub-module Topology with DC Fault Blocking Capability

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 2221-2229页

作者： Cheng peng Rui Li Xu Cai Key Laboratory of Control of Power Transmission and Conversion Shanghai Jiao Tong UniversityMinistry of EducationShanghai Jiao Tong UniversityShanghai 200240China.

Modular multilevel converter(MMC)is increasingly being applied to high voltage direct current(HVDC)***,dc short circuit situations restrain the application of a conventional half bridge MMC *** this paper,a new sub-module topology with inserted thyristor can help the MMC system clear a dc side *** states and devices voltage stress of the proposed topology are analyzed and the conduction loss comparison between the proposed topology with several existing topologies with dc fault blocking capability is carried *** show the proposed topology is superior to other topologies in terms of conduction loss while using the same voltage rating ***,compared with traditional half bridge topology,only thyristors and diodes are added in the proposed ***,cost of the proposed topology can be lower than conventional hybrid MMC *** last,the fault blocking capability of the proposed topology is verified in the simulation.

关键词： Fault current limiting high voltage direct current(HVDC)transmission modular multilevel converter(MMC)

Superior piezoelectricity in lead-free barium titanate piezoceramics

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Journal of Materiomics 2024年第3期10卷 694-706页

作者： Enpei Cai Shiqiang peng Qibin Liu School of Materials and Metallurgy Guizhou UniversityGuiyang550025China Key Laboratory of Advanced Manufacturing Technology of the Ministry of Education Guiyang550025China

Since the 21st century,increasing environmental protection and human health concern have been the driving force to develop lead-free piezoelectric materials with enhanced performances,and phase en-gineering strategy has been validated to be a viable method in numerous ***,we gained a superb d_(33)~(637±30)pC/N in lead-free(1-x)(Ba_(0.93)Ca_(0.07))(Sn_(0.08)Ti_(0.92))O_(3-x)(Sb_(0.5)Li_(0.5))TiO_(3)[abbreviated as(1-x)BCST-xSLT,0≤x≤0.4%(in mole)]piezoelectrics utilizing chemical *** illustrate the relationship among composition-structure-performance,microstructure characterization,electrical properties measurement,first-principles calculation,and phase-field simulations were ***-resolved polarization mapping of z-contrast imaging manifests the ferroelectric three phases(ReOeT)coexist at the nanoscale with nanoscale polarization switching among *** calculations and simulations confirm that the high-density nano-domain boundary bridges the poly-phase coexisting nano-domains,which makes the polarization reversal easy,thus significantly reducing the energy barrier and polarization anisotropy among different phases.

关键词： Chemical doping Relaxor ferroelectrics Phase-field simulations Phase engineering strategy First-principles calculations

Software Vulnerability Mining and Analysis Based on Deep Learning

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Computers, Materials & Continua 2024年第8期80卷 3263-3287页

作者： Shibin Zhao Junhu Zhu Jianshan peng State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou450001China

In recent years,the rapid development of computer software has led to numerous security problems,particularly software *** flaws can cause significant harm to users’privacy and *** security defect detection technology relies on manual or professional reasoning,leading to missed detection and high false detection *** intelligence technology has led to the development of neural network models based on machine learning or deep learning to intelligently mine holes,reducing missed alarms and false ***,this project aims to study Java source code defect detection methods for defects like null pointer reference exception,XSS(Transform),and Structured Query Language(SQL)***,the project uses open-source Javalang to translate the Java source code,conducts a deep search on the AST to obtain the empty syntax feature library,and converts the Java source code into a dependency *** feature vector is then used as the learning target for the neural *** types of Convolutional Neural Networks(CNN),Long Short-Term Memory(LSTM),Bi-directional Long Short-Term Memory(BiLSTM),and Attention Mechanism+Bidirectional LSTM,are used to investigate various code defects,including blank pointer reference exception,XSS,and SQL injection *** results show that the attention mechanism in two-dimensional BLSTM is the most effective for object recognition,verifying the correctness of the method.

关键词： Vulnerability mining software security deep learning static analysis

Two-component dimers of ultracold atoms with center-of-mass-momentum dependent interactions

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Communications in Theoretical Physics 2024年第4期76卷 153-157页

作者： Yaru Liu Shu Yang peng Zhang Department of Physics Renmin University of ChinaBeijing 100872China Graduate School of China Academy of Engineering Physics Beijing 100193China Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China

In a previous paper[***.A95,060701(R)(2017)],we demonstrated that a new type of two-body interaction,which depends on the center of mass(CoM)momentum,can be realized for ultracold atoms via laser-modulated magnetic Feshbach resonance(MFR).Further studies(e.g.L He et al,***.120,045302(2018))show that various interesting phenomena,such as Fulde–Ferrell superfluids,can be induced by scattering between ultracold atoms with this *** this work we investigate the shallow bound states of two ultracold atoms with this type of *** show that when the magnetic field B is below the MFR point B0,two shallow bound states can appear in this ***,a'two-component dimer'or a dimer with pseudo-spin 1/2 can be formed by two ***,the dispersion curve of the dimer may have either single or double minimums in the CoM momentum *** latter case can be explained as a result from significant pseudo-spin-orbital coupling(SOC)*** results show that the ultracold gases with CoM momentum dependent interaction may be a candidate for quantum simulations with ultracold two-component molecules,especially the molecule gases with SOC.

关键词： center-of-mass-momentum dependent interaction Raman-laser modulated MFR two-component dimer

Unveiling the surface-interface properties of perovskite crystals and pivotal regulation strategies

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Nano Research 2024年第5期17卷 3950-3981页

作者： Qin Li Ziyu Wang Junjie Ma Mengqi Han peng Gao Meng Cai Yiqiang Zhang Yanlin Song Shou peng Henan Institute of Advanced Technology College of ChemistryZhengzhou UniversityZhengzhou 450001China Key Laboratory of Green Printing Institute of ChemistryChinese Academy of Sciences(ICCAS)Beijing 100190China China National Building Material Group Co. Ltd.Beijing 100036China State Key Laboratory of Advanced Technology for Float Glass Beijing 100036China

Metal-halide perovskite solar cells have garnered significant research attention in the last decade due to their exceptional photovoltaic performance and potential for *** achieving remarkable power conversion efficiency of up to 26.1%,a substantial discrepancy persists when compared to the theoretical Shockley-Queisser(SQ)*** of the most serious challenges facing perovskite solar cells is the energy loss incurred during photovoltaic conversion,which affects the SQ limits and stability of the *** significant than the energy loss occurring in the bulk phase of the perovskite is the energy loss occurring at the ***,we provide a systematic overview of the physical and chemical properties of the ***,we delve into the underlying mechanism causing the energy deficit and structural degradation at the surface-interface,aiming to enhance the understanding of carrier transport processes and structural chemical ***,we systematically summarized the primary modulating pathways,including surface reconstruction,dimensional construction,and electric-field ***,we propose directions for future research to advance the efficiency of perovskite solar cells towards the radiative limit and their widespread commercial application.

关键词： perovskite solar cells surface-interface treatment defect modification dimensional design energy regulation heterojunction and homojunction