检索结果-南通市图书馆

Optoelectronics Letters 2024年第3期20卷 171-176页

作者： SUN Jiaxing li honglian.yao yuhang YAN Qiongyan DONG Fang College of Quality and Technology Supervising Hebei UniversityBaoding 071000China National and Local Joint Engineering Center of Measuring Instruments and Metrology Systems Baoding 071000China Key Laboratory of Energy Measurement and Safety Detection Technology in Hebei Province Baoding 071000China

The origin of Angelica dahurica medicinal herbs varies, and their pharmacological effects also differ. In order to achieve rapid and accurate identification of the origin of Angelica dahurica medicinal herbs, this study utilizes laser induced breakdown spectroscopy(liBS) technology combined with machine learning algorithms to identify the original source of Angelica dahurica. Sliced samples of Angelica dahurica were taken from four regions: Hebei, Henan, Zhejiang, and Sichuan. The spectral data from the sliced samples were used as features, and different algorithms including support vector machine(SVM), back propagation(BP) neural network, genetic algorithm-back propagation(GA-BP) neural network, particle swarm optimization-back propagation(PSO-BP) neural network, convolutional neural network(CNN), and CNN-SVM were employed to classify the origin of Angelica dahurica samples.

关键词： neural origin network

Nonlinear encoding in diffractive information processing using linear optical materials

在线全文

学校读者我要写书评

暂无评论

light(Science & Applications) 2024年第8期13卷 1675-1688页

作者： yuhang li Jingxi li Aydogan Ozcan Electrical&Computer Engineering Department University of CaliforniaLos AngelesCA 90095USA Bioengineering Department University of CaliforniaLos AngelesCA 90095USA California NanoSystems Institute(CNSI) University of CaliforniaLos AngelesCA 90095USA

Nonlinear encoding of optical information can be achieved using various forms of data ***,we analyze the performances of different nonlinear information encoding strategies that can be employed in diffractive optical processors based on linear materials and shed light on their utility and performance gaps compared to the state-of-the-art digital deep neural *** a comprehensive evaluation,we used different datasets to compare the statistical inference performance of simpler-to-implement nonlinear encoding strategies that involve,e.g.,phase encoding,against data repetition-based nonlinear encoding *** show that data repetition within a diffractive volume(e.g.,through an optical cavity or cascaded introduction of the input data)causes the loss of the universal linear transformation capability of a diffractive optical ***,data repetition-based diffractive blocks cannot provide optical analogs to fully connected or convolutional layers commonly employed in digital neural ***,they can still be effectively trained for specific inference tasks and achieve enhanced accuracy,benefiting from the nonlinear encoding of the input *** results also reveal that phase encoding of input information without data repetition provides a simpler nonlinear encoding strategy with comparable statistical inference accuracy to data repetition-based diffractive *** analyses and conclusions would be of broad interest to explore the push-pull relationship between linear material-based diffractive optical systems and nonlinear encoding strategies in visual information processors.

关键词： nonlinear simpler Nonlinear

Experimental study on combustion characteristics of supersonic combustor based on alternating-wedge strut

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 Journal of Aeronautics 2024年第5期37卷 214-227页

作者： Jie li Wenyan SONG yuhang WANG School of Power Energy Northwestern Polytechnical UniversityXi’an 710129China

Acetone Planar Lase-Induced Fluorescence(PliF)and OH-PliF were employed to capture the fuel distribution and OH distribution downstream for the supersonic combustor based on the alternating-wedge *** combustion establishment process and combustion mode in the combustor under different fuel injection methods and different equivalence ratios were *** with the kerosene-PliF and OH-PliF results in the cavity combustor,a comparative analysis was conducted to understand the combustion characteristics and combustion modes between the alternating-wedge strut-based combustor and the cavity-based *** results show that the combustor is in weak combustion mode in the case of low equivalence ratio,and the combustor is in intensive combustion mode in the case of high equivalence *** lower limit of the equivalence ratio of the combustor to maintain the intensive combustion mode varies based on different fuel injection *** OH distribution under reacting condition has a strong correlation with the fuel distribution under non-reacting *** OH fluorescence signal near the injector is weaker when the fuel distribution is more *** injector position located at the base of the strut rear has better mixing performance,enabling the combustor to be in intensive combustion mode at a lower equivalence *** combustion reaction in the alternating-wedge strut-based combustor is not necessarily dominated by mass transfer due to the mixing enhancement and premixed zone downstream of strut,while the combustion reaction process in the cavity-based combustor is mainly influenced by mass transfer.

关键词： Supersonic combustor Alternating-wedge strut Cavity PliF Fuel injection Fuel distribution Combustion characteristics Combustion mode

The origins of catalytic selectivity for the electrochemical conversion of carbon dioxide to methanol

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第1期17卷 5-17页

作者： Tian Wang Yating Wang yuhang li Chunzhong li Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical NanomaterialsFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Materials Science and EngineeringEast China University of Science&TechnologyShanghai 200237China School of Chemical Engineering East China University of Science&TechnologyShanghai 200237China

The electrocatalytic conversion of carbon dioxide(CO_(2))into useful fuels and chemical feedstocks is an emerging route to alleviate global warming and reduce reliance on fossil ***(CH_(3)OH),as one of the most significant and widely used liquid fuels that can be generated by CO_(2)reduction,is essential in the chemical *** this minireview,we unravel the origins of the selective formation of CH_(3)OH via CO_(2)reduction,including catalyst composition designs,local structure modulations,and electrolyte/catalyst interface ***,the remaining challenges and perspectives for the CO_(2)-to-CH_(3)OH reduction are proposed.

关键词： methanol carbon dioxide(CO_(2))reduction reaction electrochemistry electrocatalyst catalyst-electrolyte interface

Multifunctional WSe_(2)/Co_(3)C composite for efficient electromagnetic absorption, EMI shielding, and energy conversion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1655-1665页

作者： yuhang Zhu Tingting liu lin li Maosheng Cao School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationSchool of Physics&Electron EngineeringHarbin Normal UniversityHarbin 150025China

Currently,as the electromagnetic(EM)environment becomes increasingly complex,single-function EM materials can hardly resist the increasing electromagnetic interference(EMI),and there is an urgent need to develop multifunctional EM *** this work,multifunctional WSe_(2)/Co_(3)C was prepared by simple hydrothermal *** dielectric performance and EM response were *** absorption,shielding performance,and energy conversion devices were *** tailoring the loading content,WSe_(2)/Co_(3)C can switch between EM absorption and EMI *** maximum shielding effectiveness(SE)of WSe_(2)/Co_(3)C reached 36 dB,and high reflection loss(RL)of-60.28 dB and wide effective absorption bandwidth(EAB)of 6.16 GHz can be obtained at low *** multiple EM attenuation mechanisms brought by the combination of two-dimensional(2D)WSe_(2) and magnetic Co_(3)C are considered to be the main reason for the enhanced EM attenuation *** WSe_(2)/Co_(3)C composite provides a viable candidate for developing multifunctional EM materials in 2–18 GHz.

关键词： WSe_(2) Co_(3)C electromagnetic property microwave absorption electromagnetic interference shielding energy conversion

β-C(sp^(3))−H chlorination of amide derivatives via photoinduced copper charge transfer catalysis

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 Chemical Letters 2024年第2期35卷 361-365页

作者： yuhang He Chao Tian Guanghui An Guangming li Key Laboratory of Functional Inorganic Material Chemistry (MOE) School of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080China

An atom economicβ-C(sp^(3))−H chlorination of amide derivatives has been *** mild protocol employs CuCl_(2) instead of palladium catalysts with atom-economic HCl as chlorine sources and enables the late-stage functionalization of medicine *** studies suggest a plausible visible light triggered ligand-to-metal charge transfer(LMCT)/1,4-hydrogen atom transfer(HAT)cascade.

关键词： Photoinduced copper catalysis ligand-to-metal charge transfer 1,4-Hydrogen atom transfer β-Halogenated amide Late-stage functionalization

Application of three-dimensional electron diffraction in structure determination of zeolites

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2024年第4期43卷 39-47页

作者： yuhang li Yang ling Yanhang Ma School of Physical Science and Technology&Shanghai Key Laboratory of High-resolution Electron Microscopy ShanghaiTech UniversityShanghai201210China

Zeolites have received great attention due to their wide applications in various fields such as catalysis,adsorp-tion/separation,ion exchange,*** the atomic crystal structure of zeolites is crucial to understanding their functions and exploring their *** to the difficulty of synthesizing large single crystals,the structures of many zeolites cannot be solved using conventional single-crystal X-ray diffraction(SCXRD)***-dimensional electron diffraction(3D ED)has witnessed rapid development during the past decade and has shown its powerful ability in the structure determination of *** this review,we will briefly introduce the history of 3D ED and summarize recent advances in the application of 3D ED for the analysis of zeolite structures,along with several typical examples in this research field.

关键词： Electron diffraction Three-dimensional electron diffraction Zeolite Structure solution Electron crystallography

Electrolyte-gated SrCoO_(x) FET sensor for highly sensitive detecting pH in extreme alkalinity solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 3079-3086页

作者： Han Zhou Gaocan Qi Wenbin li yuhang Wang Zhihao Yuan School of Materials Science and Engineering Tianjin Key Lab of Photoelectric Materials&Devicesand Key Laboratory of Display Materials and Photoelectric Devices(Ministry of Education)Tianjin University of TechnologyTianjin 300384China

The pH monitoring is significantly important in chemical industry,biological process,and pollution ***,it remains a great challenge to measure pH in extreme alkalinity ***,we employ an electrolyte-gated field-effect-transistor(FET)strategy using non-stoichiometric SrCoO_(x) with rich oxygen-vacancy defects as channel materials for detecting extreme *** corresponding channel can provide effective oxygen-ion-migration sites for reversible transformation of OH-↔O_(2)-+H^(+)driven by electric *** resultant electrolyte-gated FET sensor exhibits a sensitive linear response to high concentrations of alkaline solution,1–20 ***,the sensor has the ability to directly indicate the pH values ranging from 14.0 to 17.0 in consideration of ion-activity coefficient *** work offers a great possibility for directly detecting base concentration as well as pH values in extreme alkaline solutions.

关键词： field-effect-transistor(FET) pH sensor extreme alkaline solution SrCoO_(x) oxygen-ion migration

All-optical complex field imaging using diffractive processors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

light(Science & Applications) 2024年第6期13卷 1122-1139页

作者： Jingxi li yuhang li Tianyi Gan Che-Yung Shen Mona Jarrahi Aydogan Ozcan Electrical and Computer Engineering Department University of CaliforniaLos AngelesCA90095USA Bioengineering Department University of CaliforniaLos AngelesCA90095USA California NanoSystems Institute(CNSI) University of CaliforniaLos AngelesCA90095USA

Complex field imaging,which captures both the amplitude and phase information of input optical fields or objects,can offer rich structural insights into samples,such as their absorption and refractive index ***,conventional image sensors are intensity-based and inherently lack the capability to directly measure the phase distribution of a *** limitation can be overcome using interferometric or holographic methods,often supplemented by iterative phase retrieval algorithms,leading to a considerable increase in hardware complexity and computational ***,we present a complex field imager design that enables snapshot imaging of both the amplitude and quantitative phase information of input fields using an intensity-based sensor array without any digital *** design utilizes successive deep learning-optimized diffractive surfaces that are structured to collectively modulate the input complex field,forming two independent imaging channels that perform amplitude-to-amplitude and phase-to-intensity transformations between the input and output planes within a compact optical design,axially spanning~100 *** intensity distributions of the output fields at these two channels on the sensor plane directly correspond to the amplitude and quantitative phase profiles of the input complex field,eliminating the need for any digital image reconstruction *** experimentally validated the efficacy of our complex field diffractive imager designs through 3D-printed prototypes operating at the terahertz spectrum,with the output amplitude and phase channel images closely aligning with our numerical *** envision that this complex field imager will have various applications in security,biomedical imaging,sensing and material science,among others.

关键词： field. utilize collective

The study of lithographic variation in resistive random access memory

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Semiconductors 2024年第5期45卷 69-79页

作者： yuhang Zhang Guanghui He Feng Zhang Yongfu li Guoxing Wang Department of Micro-Nano Electronics Shanghai Jiao Tong UniversityShanghai 200240China MoE Key Lab of Artificial Intelligence Shanghai Jiao Tong UniversityShanghai 200240China Institute of Microelectronics Chinese Academy of SciencesBeijing 100029China

Reducing the process variation is a significant concern for resistive random access memory(RRAM).Due to its ultrahigh integration density,RRAM arrays are prone to lithographic variation during the lithography process,introducing electrical variation among different RRAM *** this work,an optical physical verification methodology for the RRAM array is developed,and the effects of different layout parameters on important electrical characteristics are systematically *** results indicate that the RRAM devices can be categorized into three clusters according to their locations and lithography *** read resistance is more sensitive to the locations in the array(~30%)than SET/RESET voltage(lication of the optical proximity correction technique can help to reduce the variation to less than 10%,whereas it reduces RRAM read resistance by 4×,resulting in a higher power and area *** such,we provide design guidelines to minimize the electrical variation of RRAM arrays due to the lithography process.

关键词： layout lithography process variation resistive random access memory