检索结果-南通市图书馆

NANOTECHNOLOGY AND PRECISION ENGINEERING 2024年第3期7卷 71-78页

作者： Zhao, Wei Xu, Zongwei wang, pengfei Chen, Hanyi Tianjin Univ State Key Lab Precis Measuring Technol & Instrumen Tianjin 300072 Peoples R China Univ Sci & Technol China Dept Modern Phys Hefei 230026 Peoples R China

Nitrogen vacancy (NV) color centers in diamond have useful applications in quantum sensing and fluorescent marking. They can be generated experimentally by ion implantation, femtosecond lasers, and chemical vapor deposition. However, there is a lack of studies of the yield of NV color centers at the atomic scale. In the molecular dynamics simulations described in this paper, NV color centers are prepared by ion implantation in diamond with pre-doped nitrogen and subsequent annealing. The differences between the yields of NV color centers produced by implantation of carbon (C) and nitrogen (N) ions, respectively, are investigated. It is found that C-ion implantation gives a greater yield of NV color centers and superior location accuracy. The effects of different pre-doping concentrations (400-1500 ppm) and implantation energies (1.0-3.0 keV) on the NV color center yield are analyzed, and it is shown that a pre-doping concentration of 1000 ppm with 2 keV C-ion implantation can produce a 13% yield of NV color centers after 1600 K annealing for 7.4 ns. Finally, a brief comparison of the NV color center identification methods is presented, and it is found that the error rate of an analysis utilizing the identify diamond structure + coordination analysis method is reduced by about 7% compared with conventional identification methods.

关键词： NV color center Ion implantation Molecular dynamics (MD) simulation Yield enhancement NV CENTERS

The Predictability Limit of Oceanic Mesoscale Eddy Tracks in the South China Sea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第9期41卷 1661-1679页

作者： Hailong LIU Pingxiang CHU Yao MENG Mengrong DING pengfei LIN Ruiqiang DING pengfei wang Weipeng ZHENG LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Laoshan Laboratory Qingdao 266237China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Marine Science and Technology College Zhejiang Ocean UniversityZhoushan 316022China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100872China Center for Monsoon System Research(CMSR) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100190China

Employing the nonlinear local Lyapunov exponent (NLLE) technique, this study assesses the quantitative predictability limit of oceanic mesoscale eddy (OME) tracks utilizing three eddy datasets for both annual and seasonal means. Our findings reveal a discernible predictability limit of approximately 39 days for cyclonic eddies (CEs) and 44 days for anticyclonic eddies (AEs) within the South China Sea (SCS). The predictability limit is related to the OME properties and seasons. The long-lived, large-amplitude, and large-radius OMEs tend to have a higher predictability limit. The predictability limit of AE (CE) tracks is highest in autumn (winter) with 52 (53) days and lowest in spring (summer) with 40 (30) days. The spatial distribution of the predictability limit of OME tracks also has seasonal variations, further finding that the area of higher predictability limits often overlaps with periodic OMEs. Additionally, the predictability limit of periodic OME tracks is about 49 days for both CEs and AEs, which is 5-10 days higher than the mean values. Usually, in the SCS, OMEs characterized by high predictability limit values exhibit more extended and smoother trajectories and often move along the northern slope of the SCS.

关键词： predictability mesoscale eddy nonlinear local Lyapunov exponent South China Sea seasonal variability

Robust neutralization of SARS-CoV-2 variants including JN.1 and BA.2.87.1 by trivalent XBB vaccine-induced antibodies

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2024年第6期9卷 2359-2361页

作者： Xun wang Shujun Jiang Wentai Ma Yanliang Zhang pengfei wang Shanghai Pudong Hospital Fudan University Pudong Medical CenterState Key Laboratory of Genetic EngineeringMOE Engineering Research Center of Gene TechnologySchool of Life SciencesShanghai Institute of Infectious Disease and BiosecurityFudan UniversityShanghaiChina Department of Infectious Diseases Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese MedicineNanjing Research Center for Infectious Diseases of Integrated Traditional Chinese and Western MedicineNanjingJiangsuChina Beijing Institute of Genomics Chinese Academy of SciencesUniversity of Chinese Academy of Sciences and China National Center for BioinformationBeijingChina

Dear Editor,The rapid and widespread transmission of SARS-CoV-2 has led to the emergence of multiple variants of concern(VOCs),most notably the Omicron variant,which continues to evolve and diversify into a range of *** previous research has shown that these Omicron sub-lineages,spanning BA.1-BA.2.86,have been evolving to exhibit increased neutralization escape capabilities.

关键词： evolve neutralization variants

Tailoring the surface and interface structures of photocatalysts to enhance hydrogen production

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第4期67卷 1161-1174页

作者： Tao Zhang pengfei wang Shuai Yue Fei Li Zhiyong Zhao Sihui Zhan MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and EngineeringNankai UniversityTianjin 300350China

Photocatalytic water splitting using semiconductor photocatalysts is a promising approach for the production of carbon-neutral,sustainable and clean hydrogen ***,the separation and transport of photoinduced carriers are generally considered to be rate-limiting steps,and their low efficiency remains a major ***,much effort has been devoted to developing new strategies in surface/interface engineering of photocatalysts to improve the dynamics of charge separation/*** feature article briefly summarizes recent advances in photocatalyst surface/interface engineering by our research group,which have been achieved through the design of various novel photocatalysts,including interfacial modulation,heterostructure construction,heteroatom doping,single atom and diatom *** article is divided into three parts:first,we briefly introduce the three key processes involved in solar water splitting and reveal relationships between the properties of nanostructural photocatalysts and the fundamentals of water splitting;second,we detail methods and strategies for surface and interfacial structures to improve the efficiency of the fundamental processes,especially charge separation;finally,we explore prospects for photocatalytic water splitting *** article provides a valuable resource and strategies for researchers currently working in the field of photocatalytic water splitting.

关键词： photocatalytic water splitting surface/interface structures dual-functional photocatalysis

Reinforcement Learning Navigation for Robots Based on Hippocampus Episode Cognition

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第1期21卷 288-302页

作者： Jinsheng Yuan Wei Guo Zhiyuan Hou Fusheng Zha Mantian Li pengfei wang Lining Sun State Key Laboratory of Robotics and System Harbin Institute of Technology(HIT)Harbin 150001China Shenzhen Academy of Aerospace Technology Shenzhen 518057China School of Mechanical and Electrical Engineering Lanzhou University of TechnologyLanzhou 730050China

Artificial intelligence is currently achieving impressive success in all ***,autonomous navigation remains a major challenge for *** learning is used for target navigation to simulate the interaction between the brain and the environment at the behavioral level,but the Artificial Neural Network trained by reinforcement learning cannot match the autonomous mobility of humans and *** hippocampus–striatum circuits are considered as key circuits for target navigation planning and *** paper aims to construct a bionic navigation model of reinforcement learning corresponding to the nervous system to improve the autonomous navigation performance of the *** ventral striatum is considered to be the behavioral evaluation region,and the hippocampal–striatum circuit constitutes the position–reward *** this paper,a set of episode cognition and reinforcement learning system simulating the mechanism of hippocampus and ventral striatum is constructed,which is used to provide target guidance for the robot to perform autonomous *** with traditional methods,this system reflects the high efficiency of learning and better Environmental *** research is an exploration of the intersection and fusion of artificial intelligence and neuroscience,which is conducive to the development of artificial intelligence and the understanding of the nervous system.

关键词： Episode cognition Reinforcement learning Hippocampus Robot navigation

A Unifi ed View of Carbon Neutrality:Solar-Driven Selective Upcycling of Waste Plastics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2024年第1期30卷 1-26页

作者： Zhiyong Zhao Shuai Yue Gaohua Yang pengfei wang Sihui Zhan MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlCollege of Environmental Science and EngineeringTianjin 300350China

With the rapid development of plastic production and consumption globally,the amount of post-consumer plastic waste has reached levels that have posed environmental *** the substantial CO_(2)emissions throughout the plastic lifecycle from material production to its disposal,photocatalysis is considered a promising strategy for eff ective plastic recycling and *** can upgrade plastics into value-added products under mild conditions using solar energy,realizing zero carbon *** this paper,we explain the basics of photocatalytic plastic reformation and underscores plastic feedstock reformation pathways into high-value-added products,including both degradation into CO_(2)followed by reformation and direct reformation into high-value-added ***,the current applications of transforming plastic waste into fuels,chemicals,and carbon materials and the outlook on upcycling plastic waste by photocatalysis are presented,facilitating the realization of carbon neutrality and zero plastic waste.

关键词： Photocatalysis Photoreforming Plastics upcycling Carbon neutrality Energy storage and conversion

Quantifying Inter-regional Trade Inequality of China's Cities Based on Environmental-economic Benefits in Virtual Built-up Land Flow

在线全文

学校读者我要写书评

暂无评论

China & World Economy 2024年第5期32卷 226-246页

作者： pengfei wang Hongbo Li Zhenbin Huang College of Public Administration Huazhong Agricultural UniversityChina

The development of spatial interactions of land resources enhances virtual built-up land flow,which contributes to China's inter-regional trade *** is known about the degree of inequality among *** work seeks to estimate the degree of inter-regional trade inequality through environmental-economic *** combined a multiregional input-output model at the city level with a new classification to calculate the virtual built-up land flow among cities and analyzed its implications for the regional economy and carbon *** results indicate that developed regions were the main beneficiaries of inter-regional trade,as reflected in land-use ***'s economic hub has been progressively shifting southward,and the inter-regional trade inequality has continuously *** flow of virtual service industry land among developed regions rose,while underdeveloped regions remained suppliers of raw materials,further increasing inter-regional trade inequality.

关键词： built-up land carbon neutrality multiregional input-output model trade inequality

Hybrid structure of iron single atoms and metallic titanium for photothermal ethanol steam reforming

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第3期67卷 848-854页

作者： Dachao Yuan Guanda Han Zhixuan wang Jianguo Zhao Kailuan Li pengfei wang Jianjun Hao Yaguang Li Jinhua Ye College of Mechanical and Electrical Engineering Technology Innovation Center of Intelligent Agricultural EquipmentHebei Agricultural UniversityBaoding 071001China Research Center for Solar Driven Carbon Neutrality The College of Physics Science and TechnologyInstitute of Life Science and Green DevelopmentHebei UniversityBaoding 071002China International Center for Materials Nanoarchitectonics(WPI-MANA) National Institute for Materials Science(NIMS)1-1 NamikiTsukubaIbaraki 305-0044Japan Graduate School of Chemical Science and Engineering Hokkaido UniversitySapporo 060-0814Japan

Photothermal ethanol steam reforming(ESR) is currently limited by low intrinsic activity and strong solar energy ***,we synthesized Fe single atoms supported on CeO_(2)(SA Fe-CeO_(2)) to exhibit excellent low-temperature ESR activity with a hydrogen production rate of 512 mmol g^(-1)h^(-1) at 350℃,becuase of the high oxidation state of Fe single atoms to weaken the reaction barrier of ethanol ***,a heterostructure of SA Fe-CeO_(2) and Ti foil could eliminate 66% of infrared radiation via the size effect,thus achieving a 3.5 sun-driven temperature of 347℃.Consequently,the heterostructure of SA Fe-CeO_(2) and Ti foil shows a hydrogen generation rate of 984 mmol g^(-1)h^(-1) of ESR and 11.31% of solar-to-hydrogen energy conversion efficiency,which outperforms other photothermal ethanol-hydrogen production *** study provides a new path for designing active catalytic sites and trapping light energy of photothermal catalysts.

关键词： photothermal catalysis single atoms heterostructure ethanol steam reforming iron

Adaptive H_(∞)Filtering Algorithm for Train Positioning Based on Prior Combination Constraints

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第2期138卷 1795-1812页

作者： Xiuhui Diao pengfei wang Weidong Li Xianwu Chu Yunming wang Department of Mechanical Engineering Henan Institute of TechnologyXinxiang453000China School of Electrical and Information Engineering Dalian Jiaotong UniversityDalian116028China

To solve the problem of data fusion for prior information such as track information and train status in train positioning,an adaptive H∞filtering algorithm with combination constraint is proposed,which fuses prior information with other sensor information in the form of ***,the train precise track constraint method of the train is proposed,and the plane position constraint and train motion state constraints are analysed.A model for combining prior information with constraints is *** an adaptive H∞filter with combination constraints is derived based on the adaptive adjustment method of the robustness ***,the positioning effect of the proposed algorithm is simulated and analysed under the conditions of a straight track and a curved *** results show that the positioning accuracy of the algorithm with constrained filtering is significantly better than that of the algorithm without constrained filtering and that the algorithm with constrained filtering can achieve better performance when combined with track and condition information,which can significantly reduce the train positioning *** effectiveness of the proposed algorithm is verified.

关键词： Train positioning combination constraint adaptive H_(∞)filter

Real-time generation of circular patterns in electron beam lithography

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

NANOTECHNOLOGY AND PRECISION ENGINEERING 2024年第3期7卷 90-98页

作者： Li, Zhengjie Yin, Bohua Sun, Botong Huang, Jingyu wang, pengfei Han, Li Chinese Acad Sci Inst Elect Engn Beijing 100190 Peoples R China Univ Chinese Acad Sci Beijing 100190 Peoples R China

Electron beam lithography (EBL) involves the transfer of a pattern onto the surface of a substrate by first scanning a thin layer of organic film (called resist) on the surface by a tightly focused and precisely controlled electron beam (exposure) and then selectively removing the exposed or nonexposed regions of the resist in a solvent (developing). It is widely used for fabrication of integrated circuits, mask manufacturing, photoelectric device processing, and other fields. The key to drawing circular patterns by EBL is the graphics production and control. In an EBL system, an embedded processor calculates and generates the trajectory coordinates for movement of the electron beam, and outputs the corresponding voltage signal through a digital-to-analog converter (DAC) to control a deflector that changes the position of the electron beam. Through this procedure, it is possible to guarantee the accuracy and real-time control of electron beam scanning deflection. Existing EBL systems mostly use the method of polygonal approximation to expose circles. A circle is divided into several polygons, and the smaller the segmentation, the higher is the precision of the splicing circle. However, owing to the need to generate and scan each polygon separately, an increase in the number of segments will lead to a decrease in the overall lithography speed. In this paper, based on Bresenham's circle algorithm and exploiting the capabilities of a field-programmable gate array and DAC, an improved real-time circle-producing algorithm is designed for EBL. The algorithm can directly generate circular graphics coordinates such as those for a single circle, solid circle, solid ring, or concentric ring, and is able to effectively realizes deflection and scanning of the electron beam for circular graphics lithography. Compared with the polygonal approximation method, the improved algorithm exhibits improved precision and speed. At the same time, the point generation strategy is optimized

关键词： Electron beam lithography Circle production Micro-nano fabrication Pattern generator