检索结果-南通市图书馆

Gas sensor array based on carbon-based thin-film transistor for selective detection of indoor harmful gases

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4401-4411页

作者： Can Liu Yu Sun Jia-Yi Guo Xiu-Lei Li Lu Tao Jin-Yong Hu Jue-Xian Cao Ping-Hua Tang Yong Zhang school of electrical and Information engineering Hunan Institute of Engineering physics and Optoelectronics&Hunan Institute of Advanced Sensing and Information Technology Xiangtan University

The identification of indoor harmful gases is imperative due to their significant threats to human health and *** achieve accurate identification,an effective strategy of constructing a sensor array combined with the pattern recognition algorithm is ***-based thin-film transistors are selected as the sensor array unit,with semiconductor carbon nanotubes （CNTs） within the TFT channels modified with different metals （Au,Cu and Ti） for selective responses to NH3,H2S and HCHO,*** accurate gas species identification,an identification mode that combines linear discriminant analysis algorithms and logistic regression classifier is *** test results demonstrate that by preprocessing the sensor array’s sensing data with the LDA algorithm and subsequently employing the LR classifier for identification,a 100% recognition rate can be achieved for three target gases （NH3,H2S and HCHO）.This work provides significant guidance for future applications of chip-level gas sensors in the realms of the Internet of Things and Artificial Intelligence.

关键词： Carbon-based thin-film transistors Gas sensor arrays Linear discriminant analysis Multi-gas detection Semiconductor carbon nanotubes

Simultaneously enhancing erosion and compression resistance:designing AlCoCrFeNi high-entropy alloy strengthened Ag-based contacts

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4476-4492页

作者： Xiao-Yang Xue Zhe Wang Hui-Ling Nie Zhao Yuan Jun Wang Chang-Hu Xu Kai Wen Cong-Hao Yu school of Materials Science and engineering Xi’an Polytechnic University school of physics Xi’an Jiaotong University Key Laboratory of Pulsed Power Technology School of Electrical and Electronic EngineeringHuazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and Technology

Designing microstructures and unveiling dynamic erosion mechanisms remain important challenges for Ag-based contacts. To simultaneously enhance erosion and compression resistance, an Al Co Cr Fe Ni high-entropy alloy(HEA) is introduced into Ag-based materials to fabricate novel Ag-HEA contacts with island-and skeletonrestricted microstructures. The arc erosion experimental results reveal that the skeleton-restricted HEA microstructure is the key factor in reducing the hill and crater morphologies of the contact surface, effectively delaying material transfer between the movable and stationary contacts. The molten bridge evolution and compressive deformation behavior of Ag-HEA contacts with various microstructures are investigated using molecular dynamics(MD) simulations. MD results indicate that the constraint of Ag atom diffusion in the molten pool and the involvement of HEA atoms in the molten bridge are the primary mechanisms for improving erosion resistance. The skeleton-restricted HEA microstructure reduces the total energy and structural stability of the molten bridge system and promotes its fracture and disintegration. Moreover, the synergistic effect of the twin and Lomerz–Cottrell lock structures can hinder dislocation glide, generating dispersed and small-area stacking faults in the Ag matrix and mitigating the concentration of shear strains. Thus, the skeleton-restricted HEA microstructure contributes positively to compression resistance. This study presents a novel approach to designing Ag-based contacts.

关键词： Arc erosion electrical contact materials High entropy alloys Microstructures Molecular dynamics

A universal non-Hermitian platform for bound state in the continuum enhanced wireless power transfer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第4期19卷 37-46页

作者： Haiyan Zhang Zhiwei Guo Yunhui Li Yaping Yang Yuguang Chen Hong Chen school of physics Science and engineering Tongji UniversityShanghai 200092China Department of electrical engineering Tongji UniversityShanghai 201804China

Non-Hermitian systems with parity–time(PT)-symmetry have been extensively studied and rapidly developed in resonance wireless power transfer(WPT).The WPT system that satisfies PT-symmetry always has real eigenvalues,which promote efficient energy ***,meeting the condition of PT-symmetry is one of the most puzzling *** power transfer under different transmission conditions is also a great *** state in the continuum(BIC)supporting extreme quality-factor mode provides an opportunity for efficient ***,we propose theoretically and demonstrate experimentally that BIC widely exists in resonance-coupled systems without PT-symmetry,and it can even realize more stable and efficient power transfer than PT-symmetric ***,BIC for efficient WPT is universal and suitable in standard second-order and even high-order WPT *** results not only extend non-Hermitian physics beyond PT-symmetry,but also bridge the gap between BIC and practical application engineering,such as highperformance WPT,wireless sensing and communications.

关键词： non-Hermitian physics parity-time asymmetry bound state in the continuum wireless power transfer

Research of caged dynamics of clusters center atoms in Pd_(82)Si_(18) amorphous alloy

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

Chinese physics B 2024年第4期33卷 623-629页

作者：邓永和陈贝祁清华李兵兵高明文大东王小云彭平 school of Computational Science and Electronics Hunan Institute of EngineeringXiangtan 411104China school of physics and Mechanical&electrical engineering Jishou UniversityJishou 416000China school of Materials Science and engineering Hunan UniversityChangsha 410082China

To date,there is still a lack of a comprehensive explanation for caged dynamics which is regarded as one of the intricate dynamic behaviors in amorphous *** study focuses on Pd_(82)Si_(18)as the research object to further elucidate the underlying mechanism of caged dynamics from multiple perspectives,including the cage's lifetime,atomic local environment,and atomic potential *** results reveal that Si atoms exhibit a pronounced cage effect due to the hindrance of Pd atoms,resulting in an anomalous peak in the non-Gaussian *** in-depth investigation was conducted on the caged dynamics differences between fast and slow Si *** comparison to fast Si atoms,slow Si atoms were surrounded by more Pd atoms and occupied lower potential energy states,resulting in smaller diffusion displacements for the slow Si ***,slow Si atoms tend to be in the centers of smaller clusters with coordination numbers of 9 and *** the isothermal relaxation process,clusters with coordination numbers 9 and 10 have longer lifetimes,suggesting that the escape of slow Si atoms from their cages is more *** findings mentioned above hold significant implications for understanding the caged dynamics.

关键词： caged dynamics Pd_(82)Si_(18) amorphous alloy fast and slow atoms clusters lifetime

Periodic event-triggered secure consensus for networked mechanical systems under Denial-of-Service attacks

在线全文

学校读者我要写书评

暂无评论

Control Theory and Technology 2024年第1期22卷 1-13页

作者： Shiqi Zheng Zhipeng Li Chao Zhai Peng Shi school of Automation China University of GeosciencesWuhan430074HubeiChina school of electrical and Electronic engineering The University of AdelaideAdelaideSA5005Australia school of Electronic Electrical Engineering and PhysicsFujian University of TechnologyFuzhou350100FujianChina

This paper concentrates on the secure consensus problem of networked mechanical/Euler–Lagrange ***,a new periodic event-triggered(PET)secure distributed observer is proposed to estimate the leader *** proposed distributed observer only relies on the PET data from its neighbors,which can significantly reduce the communication and computational *** importantly,it is secure in the sense that it can work normally regardless of the Denial-of-Service(DoS)***,based on the proposed distributed observer,an adaptive fuzzy control law is proposed for each Euler–Lagrange system.A PET mechanism is integrated into the controller,which can reduce the control *** is helpful for both energy saving and fault tolerance of ***,the PET mechanism naturally makes the controller easy to be implemented in digital *** property of fuzzy logic systems and Gronwall inequality are skillfully utilized to show the stability of the closed-loop ***,the proposed control scheme is verified on real Euler–Lagrange systems,which contain a robot manipulator and several servo motors.

关键词： Output regulation Mechanical/Euler-Lagrange systems Periodic event-triggered mechanism Denial-of-Service attacks

Mechanical and magnetocaloric adjustable properties of Fe3O4/PET deformed nanoparticle film

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

Chinese physics B 2024年第3期33卷 589-595页

作者：范凤国段林彤 school of physics and electrical Information Shangqiu Normal UniversityShangqiu 476000China

The flexibility of nanoparticle films is a topic of rapidly growing interest in both scientific and engineering researches due to their numerous potential applications in a broad range of wearable electronics and biomedical *** article presents the elucidation of the properties of nanoparticle ***,a flexible film is fabricated based on polyethylene terephthalate(PET)and magnetic iron oxide at the nanoscale using layer-by-layer *** 2D thin flexible film material can be bent at different angles from 0°to 360°.With an increase in elastic deformation angles,the magnetocaloric effect of the film gradually increases in the alternating magnetic *** test results from a vibrating sample magnetometer and a low-frequency impedance analyzer demonstrate that the film has a good magnetic response and *** magnetocaloric effect and magnetic induction effect are controlled by deformation,providing a new idea for the application of elastic *** combines the flexibility of the nanoparticle PET substrate and,in the future,it may be used for skin adhesion for administration and magnetic stimulation control.

关键词： nanoparticle film deformation magnetic properties flexible substrates

Layer-by-layer epitaxy growth of thickness-controllable two-dimensional tungsten disulfide

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第5期67卷 302-310页

作者： Jieyuan LIANG Zixing ZOU Junwu LIANG Di WANG Biao WANG Anshi CHU Jiali YI Cheng ZHANG Lizhen FANG Tian ZHANG Huawei LIU Xiaoli ZHU Dong LI Anlian PAN Key Laboratory for Micro-Nano physics and Technology of Hunan Province State Key Laboratory of Chemo/Biosensing and Chemometrics Hunan Institute of Optoelectronic IntegrationCollege of Materials Science and Engineering School of Physics and ElectronicsHunan University school of Electronic Information and electrical engineering Changsha University school of physics and Telecommunication engineering Yulin Normal University Units Semiconductor Technology Co. Ltd. school of physics and Electronics Hunan Normal University

Bilayer transition metal dichalcogenides（TMDs） balance the high mobility of single layers with the high state density of multilayers and therefore have promising application prospects in high-performance electronics. However, the layer-controlled growth of 2D materials is still confronted with challenges such as poor repeatability between different labs and a limited understanding of the growth mechanism at the atomic scale. Herein, we report a new carbon-assisted chemical vapor deposition process that can realize the growth of WS2sheets with high yield, precise thickness controllability, and repeatability. We show that carbon can act as a reducing agent and catalyst that preferentially reacts with the WO3precursor to form intermediate WO3-xproducts with low-valence state W. The resulting oxycarbide gas has a low surface adsorption energy when deposited on the surface of as-grown WS2, which provides nucleation sites for the subsequent layer of WS2growth and leads to the vertical growth of WS2sheets. The growth mechanism is thoroughly investigated. electrical transport measurements show that the produced bilayer WS2possesses a high carrier mobility(up to 58 cm2·V-1·s-1) and small subthreshold swing（estimated to be 148 mV/decade）,which are among the best reported results for TMDs produced using CVD.

关键词： WS$_2$ thickness-controlled growth chemical vapor deposition additive carbon

Level pinning of anti-PT-symmetric circuits for efficient wireless power transfer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第1期11卷 215-224页

作者： Zhiwei Guo Fengqing Yang Haiyan Zhang Xian Wu Qiong Wu Kejia Zhu Jun Jiang Haitao Jiang Yaping Yang Yunhui Li Hong Chen MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Sciences and Engineering Tongji University Department of electrical engineering Tongji University school of Automotive Studies Tongji University

Wireless power transfer(WPT) technology based on magnetic resonance(a basic physical phenomenon)can directly transfer energy from the source to the load without wires and other physical contacts, and has been successfully applied to implantable medical devices, electric vehicles, robotic arms and other ***, due to the frequency splitting of near-field coupling, the resonant WPT system has some unique limitations, such as poor transmission stability and low efficiency. Here, we propose anti-resonance with level pinning for high-performance WPT. By introducing the anti-resonance mode into the basic WPT platform, we uncover the competition between dissipative coupling and coherent coupling to achieve novel level pinning, and construct an effective anti-parity-time(anti-PT)-symmetric non-Hermitian system that is superior to previous PT-symmetric WPT schemes. On the one hand, the eigenvalue of the anti-PT-symmetric system at resonance frequency is always pure real in both strong and weak coupling regions, and can be used to overcome the transmission efficiency decrease caused by weak coupling, as brought about by, for example, a large size ratio of the transmitter to receiver, or a long transmission *** the other hand, due to the level pinning effect of the two kinds of coupling mechanisms, the working frequency of the system is guaranteed to be locked, so frequency tracking is not required when the position and size of the receiver change. Even if the system deviates from the matching condition, an efficient WPT can be realized, thereby demonstrating the robustness of the level pinning. The experimental results show that when the size ratio of the transmitter coil to the receiver coil is 4.29(which is in the weak coupling region), the transfer efficiency of the anti-PT-symmetric system is nearly 4.3(3.2) times higher than that of the PT-symmetric system when the matching conditions are satisfied(deviated). With the miniaturization and integration of d

关键词： non-Hermitian system wireless power transfer anti-PT-symmetric circuits synthetic dimension metamaterials

Utilizing quantum coherence in Cs Rydberg atoms for high-sensitivity room-temperature terahertz detection: a theoretical exploration

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第7期12卷 1583-1592页

作者： LEI HOU JUNNAN WANG QIHUI HE SUGUO CHEN LEI YANG SUNCHAO HUANG WEI SHI Department of physics Xi’an University of TechnologyXi’an 710048China school of electrical engineering Xi’an University of TechnologyXi’an 710048China school of electrical and Electronic engineering Nanyang Technological UniversitySingapore 610101Singapore

In recent years,terahertz (THz) technology has made significant progress in numerous applications;however,the highly sensitive,room-temperature THz detectors are still rare,which is one of the bottlenecks in THz *** this paper,we proposed a room-temperature electrometry method for THz detection by laser spectroscopy of cesium(^(133)Cs) Rydberg atoms,and conducted a comprehensive investigation of the five-level system involving electromagnetically induced transparency (EIT),electromagnetically induced absorption (EIA),and Autler–Townes (AT) splitting in^(133)Cs *** solving the Lindblad master equation,we found that the influence of the THz electric field,probe laser,dressing laser,and Rydberg laser on the ground state atomic population as well as the coherence between the ground state and the Rydberg state,plays a crucial role in the transformation and amplitude of the EIT and EIA *** and the atomic vapor cell’s dimensions affect the number of^(133)Cs atoms involved in the detection,and ultimately determine the *** predicted the proposed quantum coherence THz detection method has a remarkable sensitivity of as low as 10^(-9)V m^(-1)Hz^(-1/2).This research offers a valuable theoretical basis for implementing and optimizing quantum coherence effects based on Rydberg atoms for THz wave detection with high sensitivity and room-temperature operation.

关键词： quantum Rydberg dimensions