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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

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

Vertically grown MoS_(2)nanosheets on graphene with defect-rich structure for efficient sodium storage

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Rare Metals 2024年第3期43卷 1062-1071页

作者： Ying Wang Jia-peng He Han-Qing Pan Qing-peng Wang Lei Zhang Yong-Chang Liu Qing-Hong Wang School of Chemistry&Materials Science Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional MaterialsJiangsu Normal UniversityXuzhou221116China Institute of Biopharmaceutical Research Liaocheng UniversityLiaocheng252059China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyState Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing100083China Centre for Catalysis and Clean Energy Gold Coast CampusGriffith UniversityGold CoastQLD4222Australia

The synthesis of a perpendicular growth structure of MoS_(2)nanosheets on graphene for efficient sodium storage is challenging yet ideal due to the benefits of open ion diffusion channels and high electronic *** this study,we have successfully fabricated a novel structure of vertical MoS_(2)nanosheets on graphene,with ZnS nanoparticles serving as bonding points(MoS_(2)/ZnS/G),through a facile hydrothermal *** the synthesis process,Zn^(2+)not only acts as a landing site for the vertical growth of MoS_(2)nanosheets but also triggers the formation of a defect-rich structure in the final *** unique architecture of MoS_(2)/ZnS/G effectively combines the advantages of a vertically aligned geometry and a defectrich structure for energy *** resulting structure displays shortened transport paths for electrons/ions,enhanced conductivity,improved structural integrity,and an increased number of active sites for promising electrochemical *** expected,when used as anode for sodium-ion batteries,the as-synthesize d MoS_(2)/ZnS/G exhibits excellent rate capability(high capacity of 298 mAh·g^(-1)at 5 A·g^(-1))and good cycling stability(a capacity decay of 0.056%per cycle after 500 cycles at 1 A·g^(-1)).According to the kinetic investigations,the electrochemical process of the MoS_(2)/ZnS/G sample is primarily governe d by a pseudocapacitive behavior,which enhances the charge/discharge kinetics and allows the MoS_(2)/ZnS/G structure to remain intact during cycling.

关键词： MoS_(2) Perpendicular growth Graphene Sodium storage Electrochemical performance

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

Reducing idleness in financial cloud services via multi-objective evolutionary reinforcement learning based load balancer

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Science China(Information Sciences) 2024年第2期67卷 20-40页

作者： peng YANG Laoming ZHANG Haifeng LIU Guiying LI Department of Statistics and Data Science Southern University of Science and Technology Guangdong Provincial Key Laboratory of Brain-Inspired Intelligent Computation Department of Computer Science and EngineeringSouthern University of Science and Technology Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology Guangdong OPPO Mobile Telecommunications Corp. Ltd Research Institute of Trustworthy Autonomous Systems Southern University of Science and Technology

In recent years, various companies have started to shift their data services from traditional data centers to the cloud. One of the major motivations is to save on operational costs with the aid of cloud elasticity. This paper discusses an emerging need from financial services to reduce the incidence of idle servers retaining very few user connections, without disconnecting them from the server side. This paper considers this need as a bi-objective online load balancing problem. A neural network based scalable policy is designed to route user requests to varied numbers of servers for the required elasticity. An evolutionary multi-objective training framework is proposed to optimize the weights of the policy. Not only is the new objective of idleness reduced by over 130% more than traditional industrial solutions, but the original load balancing objective itself is also slightly improved. Extensive simulations with both synthetic and real-world data help reveal the detailed applicability of the proposed method to the emergent problem of reducing idleness in financial services.

关键词： evolutionary reinforcement learning evolutionary multi-objective optimization load balance cloud computing

Local Hamilton type Gradient Estimates and Harnack Inequalities for Nonlinear Parabolic Equations on Riemannian Manifolds

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 539-546页

作者： Wen WANG Da-peng XIE Hui ZHOU School of Mathematics and Statistics Hefei Normal UniversityHefei 230601China

In this paper,we prove a local Hamilton type gradient estimate for positive solution of the nonlinear parabolic equation ut(x,t)=Δu(x,t)+au(x,t) ln u(x,t)+bu^(α)(x,t),on M×(-∞,∞) with α∈R,where a and b are *** ... 详细信息

关键词： nonlinear parabolic equation gradient estimate Harnack inequality

Weyl Type Theorem for Bounded Linear Operator and Its Functional Calculus

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Acta Mathematica Sinica,English Series 2024年第2期40卷 528-536页

作者： Gao Hui Zi FENG peng Tong LI School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

Let H be a complex infinite dimensional Hilbert space and B(H)be the algebra of all bounded linear operators on *** this paper,we mainly study the operators that satisfy both a-Weyl's theorem and property(R).Also,the operators whose functional calculus satisfies the two properties are also *** give the features for the operator or its functional calculus for which both a-Weyl's theorem and property(R)hold.

关键词： a-Weyl's theorem property(R) functional calculus

Multifunctional carbon materials from rugose rose for energy storage and water purification

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 1-13页

作者： peng-Hui Li Hui Zhou Wen-Juan Wu Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry UniversityNanjing 210037China College of Light Industry and Food Engineering Nanjing Forestry UniversityNanjing 210037China College of Chemical Engineering East China University of Science and TechnologyShanghai 200237China State Key Laboratory of Chemical Engineering Shanghai 200237China

With the advancement of social process,the resource problem is becoming more prominent,biomass materials come into being,and it is becoming more and more important to explore and prepare efficient and multifunctional biomass materials to alleviate the problems of energy storage and water *** this paper,nitrogen-doped hierarchical porous carbon materials(NRRC)were produced by one-step carbonization of withered rose as raw material and melamine as nitrogen source with KOH-activated *** resulting nitrogen-doped porous carbon material had the most abundant pores and the best microspherical graded pore structure,with a specific surface area of up to 1393 m2·g^(-1),a pore volume of 0.68 cm3·g^(-1),and a nitrogen-doped content of 5.52%.Electrochemical tests showed that the maximum specific capacitance of NRRC in the three-electrode system was 346.4 F·g^(-1)(0.5 A·g^(-1)),which was combined with favorable capacitance retention performance and cycling *** NRRC//NRRC symmetric supercapacitors were further assembled,and the maximum energy density of a single device was 23.88 Wh·kg^(-1),which still maintains excellent capacitance retention and cyclic charging/discharging *** example,the capacitance retention rate was always close to 96.27%with almost negligible capacitance loss after 10000 consecutive charge/discharge cycles(current density:10 A·g^(-1)).Regardless of the three-electrode or two-electrode system,the super capacitive performance of NRRC porous carbon materials was comparable to the electrochemical performance of many reported biomass porous carbon materials,which showed better energy storage advantages and practical application *** addition,NRRC porous carbon materials had excellent water purification *** dye adsorption test confirmed that NRRC had a high adsorption capacity(491.47 mg·g^(-1))for methylene *** undoubtedly also showed a potential and promising avenue for high value-added utilization

关键词： rose carbon adsorption electrode material electrochemical performance

How the enhanced East Asian summer monsoon regulates total gross primary production in eastern China

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Advances in Climate Change Research 2024年第2期15卷 244-252页

作者： Ming-Yu HAN Yong ZHANG Jing peng China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China China Meteorological Administration Institute for Development and Programme Design Beijing 100081China CAS Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of Sciences(CAS)Beijing 100029China

Recognizing the relationship between gross primary production(GPP)and precipitation in eastern China,the East Asian Summer Monsoon(EASM)plays a crucial role in shaping *** confirmation of the strong link between EASM and GPP,there remains a notable research gap in understanding the specific impact of the EASM on GPP in different regions of eastern *** we used simulations from Trends in Net Land-Atmosphere Carbon Exchanges(TRENDY)models from 1951 to 2010 and divided eastern China into five subregions for the *** also used the New East Asian Summer Monsoon Index(NEWI)as a quantitative metric to distinguish between periods of strong and weak *** on this,this study aims to investigate the response of GPP in different subregions of eastern ***,under strengthened EASM years(1954,1957,1965,1969,1977,1980,1983,1987,1993 and 1998),East China experienced the most pronounced increase in GPP at 12±21(mean±1 sigma)gC m^(-2) mon^(-1) compared to the weak EASM years(1958,1961,1972,1973,1978,1981,1985,1994,1997 and 2004).In contrast,Southwest China showed a decline in GPP at-4±10 gC m^(-2) mon^(-1).Moreover,GPP also increased in Northeast and North China when EASM strengthened,while South China showed a decline in *** indicated that GPP changed with monsoon *** to the mechanism analysis,during strong EASM,there was intense moisture convergence through alterations in the atmospheric circulation field over East China and abundant precipitation,which further contributed to the increase in *** solar radiation in Southwest China decreased with EASM enhancement,which suppressed GPP and hindered vegetation ***,the results highlight the importance of accurately predicting the impact of different EASM intensities of regional carbon fluxes.

关键词： Gross primary production Surface air temperature Precipitation Solar radiation Eastern China Carbon cycle