检索结果-南通市图书馆

Light-modulated vertical heterojunction phototransistors with distinct logical photocurrents

Light(science & Applications) 2020年第1期9卷 407-416页

作者： Jiayue Han Meiyu He Ming Yang Qi Han Fang Wang Fang Zhong Mengjian Xu Qing Li He Zhu Chongxin Shan Weida Hu Xiaoqing Chen Xinran Wang Jun Gou Zhiming Wu Jun Wang School of Optoelectronic science and engineering University of Electronic Science and Technology of ChinaChengdu 610054China State Key Laboratory of Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of Science500 Yutian RoadShanghai 200083China Hangzhou institute for advanced study University of Chinese Academy of SciencesHangzhou 310024China Henan Key Laboratory of Diamond Optoelectronic Materials and Devices School of Physics and EngineeringZhengzhou UniversityZhengzhou 450001China National Laboratory of Solid State Microstructures School of Electronic Science and Engineeringand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China

The intriguing carrier dynamics in graphene heterojunctions have stimulated great interest in modulating the optoelectronic features to realize high-performance ***,for most phototransistors,the photoresponse characteristics are modulated with an electrical gate or a static *** this paper,we demonstrate a graphene/C_(60)/pentacene vertical phototransistor to tune both the photoresponse time and photocurrent based on light *** exploiting the power-dependent multiple states of the photocurrent,remarkable logical photocurrent switching under infrared light modulation occurs in a thick C_(60) layer(11 nm)device,which implies competition of the photogenerated carriers between graphene/C_(60) and C_(60)/***,we observe a complete positive-negative alternating process under continuous 405 nm ***,infrared light modulation of a thin C_(60)(5 nm)device results in a photoresponsivity improvement from 3425 A/W up to 7673 A/W,and we clearly probe the primary reason for the distinct modulation results between the 5 and 11 nm C_(60) *** addition,the tuneable bandwidth of the infrared response from 10 to 3×10^(3) Hz under visible light modulation is *** distinct types of optical modulation phenomena and logical photocurrent inversion characteristics pave the way for future tuneable logical photocurrent switching devices and high-performance phototransistors with vertical graphene heterojunction structures.

关键词： heterojunction transistors optoelectronic

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Self-propagating synthesis joining of C_(f)/Al composites and TC4 alloy using AgCu filler with Ni-Al-Zr interlayer

引用

Rare Metals 2021年第7期40卷 1817-1824页

作者： Lei Shen Zhuo-Ran Li Guang-Jie Feng Shu-Ye Zhang Zhi Zhou Peng He State Key Laboratory of advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China College of Materials science and engineering Chongqing UniversityChongqing 400044China

The successful joining of carbon fiber-reinforced aluminum matrix(C_(f)/Al)composites and TC4 alloy can produce composite structure and meet the demands of lightweight in aerospace *** to now,few experimental researches have been reported on the joining of C_(f)/Al composites and TC4 *** this study,the AgCu foils and Ni-Al-Zr compact were designed for the self-propagating high-temperature synthesis joining of these two materials.C_(f)/Al composites were joined with a reactive Ti plated on its joining *** typical microstructure of TC4/(AgCu/Ni-Al-Zr/AgCu)/Ti/C_(f)/Al joint was analyzed,and the effects of joining condition on microstructural evolution of the SHS joint were investigated.A thin reaction layer of Ni-Al-Ti intermetallic compounds was formed adjacent to the TC4 *** a result,AgCu foils could reduce the effect of reaction heat on the substrates and improve the joint shear *** the thickness of AgCu foils reaches 150 lm,the Ni-Al-Zr interlayer mainly acts as auxiliary heat *** joining pressure caused the active elements to diffuse into C_(f)/Al composites and weakened the shear strength of the ***,the joint shear strength could reach 36.4 MPa when the AgCu foils were 50 lm and the joining pressure was 2 MPa.

关键词： Cf/Al composites TC4 alloy Self-propagating high-temperature synthesis joining Microstructure Shear strength

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Rotordynamic characteristics prediction for scallop damper seals using computational fluid dynamics

引用

Chinese Journal of Aeronautics 2022年第8期35卷 92-106页

作者： Wanfu ZHANG Lu YIN Li YANG Haoyang TIAN Chun LI School of Energy and Power engineering University of Shanghai for Science and TechnologyShanghai 200093China Electric Power Research institute of State Grid Shanghai Municipal Electric Power CompanyShanghai 200437China

Enhancing damping characteristic is one of the effective methods to solve the instability problem of the rotor *** three-dimensional numerical analysis model of scallop damper seal was established,and the effects of inlet pressures,preswirl ratios,rotational speeds,interlaced angles and seal cavity depths on the rotordynamic characteristics of scallop damper seal were studied based on dynamic mesh method and multi-frequencies elliptic whirling *** show that the direct stiffness of the scallop damper seal increases with decreasing inlet pressure and increasing rotational speed and cavity *** the seal cavity is interlaced by a certain angle,which shows positive direct *** effective damping of the scallop damper seal increases with the increasing inlet pressure,the decreasing preswirl ratio and the rotational speed and cavity *** exists an optimal interlaced angle to maximize the effective damping and the system *** leakage of the scallop damper seal is significantly reduced with decreasing inlet *** preswirl will reduce the leakage flowrate,and the rotational speed has a slight effect on the leakage *** leakage of the scallop damper seal decreases with increasing seal cavity depth.

关键词： computational Fluid Dynamics(CFD) Effective damping Rotordynamic characteristics Scallop damper seal Stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

AN M/M/C RETRIAL QUEUEING SYSTEM WITH BERNOULLI VACATIONS

引用

Journal of Systems science and Systems engineering 2009年第2期18卷 222-242页

作者： B.Krishna KUMAR R.RUKMANI V.THANGARAJ Department of Mathematics College of EngineeringAnna UniversityChennai600 025India Department of Mathematics Pachaiyappa's CollegeChennai600030India Ramanujan institute for advanced study in Mathematics University of MadrasChennai600 005India

In this paper, a steady-state Markovian multi-server retrial queueing system with Bernoulli vacation scheduling service is studied. Using matrix-geometric approach, various interesting and important system performance measures are obtained. Further, the probability descriptors like ideal retrial and vain retrial are provided. Finally, extensive numerical illustrations are presented to indicate the quantifying nature of the approach to obtain solutions to this queueing system.

关键词： Retrial queue Bernoulli vacation matrix-geometric methods busy period vain retrial ideal retrial

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic Stability Analysis of Backhoe Dredger Based on Time Domain Method

引用

Journal of Shanghai Jiaotong university(science) 2022年第3期27卷 339-345页

作者：陈熠画陈新权杨启欧阳义平 Collaborative Innovation Center for advanced Ship and Deep-Sea Exploration State Key Laboratory of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Jiao Tong University Underwater engineering institute Co. Ltd.Shanghai 200231China

When incidents happen with the positioning spud of a backhoe dredger,the hull loses stability,heels significantly,and may even capsize under extreme *** the hydrodynamics and spud vibrations,this paper investigates the dynamic stability of a backhoe dredger after spud failure based on the time domain *** maximum dynamic heeling angle verifies the stability of the backhoe *** identify the influences of environmental load,operating conditions,and spud-soil interactions,numerical motion simulations were conducted in the time *** main conclusions on dynamic stability consider the influences of relative environmental and operational *** study provides a powerful and efficient approach to analyze the dynamic stability of backhoe dredgers and to design flooding angles.

关键词： backhoe dredger dynamic stability spud failure time domain

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effects of praseodymium doping on thermoelectric transport properties of CaMnO_3 compound system

引用

Journal of Rare Earths 2013年第9期31卷 885-890页

作者：张飞鹏牛保成张坤书张忻路清梅张久兴 institute of Physics Henan University of Urban Construction Key Laboratory of advanced Functional Materials Chinese Ministry of EducationCollege of Materials Science and EngineeringBeijing University of Technology

The rare earth Pr doped Ca1-xPrxMnO3 （x=0, 0.06, 0.08, 0.1, 0.12, and 0.14） compound bulk samples were prepared to study the effect of Pr doping on thermoelectric transport properties of CaMnO3 compound system. The doped samples exhibited sin-gle phase composition within the experimental doping range, with condensed bulk microstructure and small porosities. The electrical resistivity was remarkably reduced for doped samples, on account of the enhanced carrier concentration;the absolute value of See-beck coefficient was deteriorated mainly due to enhanced electron carrier concentration. The electrical performances of the doped samples reflected by resistivity and Seebeck coefficient fluctuations were optimistically tuned, with an optimized power factor value of 0.342 mW/（m·K2） at 873 K for x=0.08 sample, which was very much higher comparing with that of the un-doped sample. The lattice thermal conduction was really confined, leading to distinctly repressed total thermal conductivity. The thermoelectric per-formance was noticeably improved by Pr doping and the dimensionless figure of merit ZT for the Ca0.92Pr0.08MnO3 compound was favorably optimized with the maximum value 0.16 at 873 K.

关键词： CaMnO3 compound Pr doping thermoelectric properties rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

New insights into FeS/persulfate system for tetracycline elimination:Iron valence,homogeneous-heterogeneous reactions and degradation pathways

引用

Journal of Environmental sciences 2022年第2期34卷 48-58页

作者： Jinhong Fan Ying Cai Shihao Shen Lin Gu State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai institute of Pollution Control and Ecological Security Shanghai 200092China

In this study,complete tetracycline(TTC)and above 50%of total organic carbon(TOC)were removed by Fe S/PS after 30 min under optimized *** free radicals and high-valent iron ions were identified to generate in the process,the apparent similarity between intermediate products of Fe S/PS,Fe/PS,and UV/PS systems demonstrated that the degradation of TTC was due to sulfate radicals(SO_(4)·^(-))and hydroxyl radicals(·OH).Based on the reaction between free radicals and organic matter,we speculated that TTC in the Fe S/PS system was decomposed and mineralized by dehydration,dehydrogenation,hydroxyl addition,demethylation,substitution,E-transfer,and ***,a new understanding of Fe S-mediated PS activation based on stoichiometry and kinetic analysis showed that there were both homogeneous and heterogeneous reactions that occurred in the entire ***,due to the effect of p H on the dissolution of iron ions,the homogeneous reaction became the principal process with iron ions concentration exceeding 1.35 mg/*** work provides a theoretical basis for the study of the degradation of TTC-containing wastewater by the iron-based advanced oxidation process.

关键词： Tetracycline Persulfate activation Iron valence Homogeneous-heterogeneous reactions Degradation pathways

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evaluation of the Bioavailability of Metals in Sediment from the Southern Coastal Wetland of the Qiantang Estuary by Using Diffusive Gradients in Thin Films Technique

引用

Journal of Ocean University of China 2022年第2期21卷 375-387页

作者： FENG Weihua WANG Zhifu ZHU Wenzhuo ZHENG Fangqin ZHANG Dongrong XU Hengtao Key Laboratory of engineering Oceanography Second Institute of OceanographyMNRHangzhou 310012China College of Marine science&Technology Zhejiang Ocean UniversityZhoushan 316022China

Metal pollution has become an major issue governing the wetland ecosystem *** southern coastal wetland of the Qiangtang Estuary are facing unusual perturbation due to rapid development along the embayment in recent *** study evaluated the bioavailability of metals(Cu,Pb,Cd,Cr and Zn)in the sediment of the southern coastal wetland of the Qiangtang Es-tuary using diffusive gradients in thin films(DGT)techniques and compared with several methods based on total metal *** results showed that the contents of Cr,Pb,Cd and Cu in sediment,as detected using DGT,were considerably correlated with the exchangeable fraction and the content in Phragmites australis roots,while a weak correlation was observed for ***,DGT analysis could be used to evaluate the bioavailability and potential risk of Cr,Cd,Pb and Cu for *** indices,such as DGT concentration,bioaccumulation in ***,geoaccumulation index(Igeo)and potential ecological risk index(RI),revealed that Cd was a major potential ecological risk factor along the southern coast wetland of the Qiantang Estuary,especially in the upstream region,which is potentially more vulnerable to the anthropogenic pollution.

关键词： diffusive gradients in thin films estuarine wetland metal bioavailability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Metaheuristic Optimization Algorithm for Signals Classification of Electroencephalography Channels

引用

Computers, Materials & Continua 2022年第6期71卷 4627-4641页

作者： Marwa M.Eid Fawaz Alassery Abdelhameed Ibrahim Mohamed Saber Department of Communications and Electronics Delta Higher Institute of Engineering and TechnologyMansoura35111Egypt Department of Computer engineering College of Computers and Information TechnologyTaif UniversityTaif21944Saudi Arabia Computer engineering and Control Systems Department Faculty of EngineeringMansoura UniversityMansoura35516Egypt Department of Electronics and Communications engineering Faculty of EngineeringDelta University for Science and TechnologyMansoura11152Egypt

Digital signal processing of electroencephalography(EEG)data is now widely utilized in various applications,including motor imagery classification,seizure detection and prediction,emotion classification,mental task classification,drug impact identification and sleep state *** the increasing number of recorded EEG channels,it has become clear that effective channel selection algorithms are required for various *** Whale Optimization Method(Guided WOA),a suggested feature selection algorithm based on Stochastic Fractal Search(SFS)technique,evaluates the chosen subset of *** may be used to select the optimum EEG channels for use in Brain-Computer Interfaces(BCIs),the method for identifying essential and irrelevant characteristics in a dataset,and the complexity to be *** enables(SFS-Guided WOA)algorithm to choose the most appropriate EEG channels while assisting machine learning classification in its tasks and training the classifier with the ***(SFSGuided WOA)algorithm is superior in performance metrics,and statistical tests such as ANOVA and Wilcoxon rank-sum are used to demonstrate this.

关键词： Signals metaheuristics optimization feature selection multilayer perceptron support vector machines

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Competing effects of surface catalysis and ablation in hypersonic reentry aerothermodynamic environment

引用

Chinese Journal of Aeronautics 2022年第10期35卷 56-66页

作者： Zhiliang CUI Jin ZHAO Guice YAO Jun ZHANG Zhihui LI Zhigong TANG Dongsheng WEN School of Aeronautical science and engineering Beihang UniversityBeijing100083China China Aerodynamics Research and Development Center MianyangChina Ningbo institute of Technology-Beihang University NingboZhejiang 315100China

Under hypersonic flow conditions, the complicated gas-graphene interactions including surface catalysis and surface ablation would occur concurrently and intervene together with the thermodynamic response induced by spacecraft reentry. In this work, the competing effects of surface heterogeneous catalytic recombination and ablation characteristics at elevated temperatures are investigated using the Reactive Molecular Dynamics(RMD) simulation method. A GasSurface Interaction(GSI) model is established to simulate the collisions of hyper-enthalpy atomic oxygen on graphene films in the temperature range of 500–2500 K. A critical temperature Tcaround900 K is identified to distinguish the graphene responses into two parts: at T T_(c). Contradicting to the traditional Arrhenius expression that the recombination coefficient increases with the increase of surface temperature, the value is found to be relatively uniform at T computational Fluid Dynamics(CFD) simulation method, which relies on the Arrhenius-type catalysis model, would result in large discrepancies in predicting aerodynamic heat for carbon-based materials during reentry into strong aerodynamic thermal environment.

关键词： Ablation fluid dynamics Gas-solid reaction Graphene Hypersonic reentry Molecular dynamics simulation Recombination effects

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：