检索结果-南通市图书馆

A Review of Computing with Spiking Neural Networks

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第3期78卷 2909-2939页

作者： Jiadong Wu Yinan Wang zhiwei li Lun Lu Qingjiang li College of Electronic Science and Technology National University of Defense TechnologyChangsha410073China

Artificial neural networks(ANNs)have led to landmark changes in many fields,but they still differ significantly fromthemechanisms of real biological neural networks and face problems such as high computing costs,excessive computing power,and so *** neural networks(SNNs)provide a new approach combined with brain-like science to improve the computational energy efficiency,computational architecture,and biological credibility of current deep learning *** the early stage of development,its poor performance hindered the application of SNNs in real-world *** recent years,SNNs have made great progress in computational performance and practicability compared with the earlier research results,and are continuously producing significant *** there are already many pieces of literature on SNNs,there is still a lack of comprehensive review on SNNs from the perspective of improving performance and practicality as well as incorporating the latest research *** from this issue,this paper elaborates on SNNs along the complete usage process of SNNs including network construction,data processing,model training,development,and deployment,aiming to provide more comprehensive and practical guidance to promote the development of ***,the connotation and development status of SNNcomputing is reviewed systematically and comprehensively from four aspects:composition structure,data set,learning algorithm,software/hardware development *** the development characteristics of SNNs in intelligent computing are summarized,the current challenges of SNNs are discussed and the future development directions are also *** research shows that in the fields of machine learning and intelligent computing,SNNs have comparable network scale and performance to ANNs and the ability to challenge large datasets and a variety of *** advantages of SNNs over ANNs in terms of energy efficiency and spatial-temporal data processing

关键词： Spiking neural networks neural networks brain-like computing artificial intelligence learning algorithm

Elliptical vibration chiseling:a novel process for texturing ultra-high-aspect-ratio microstructures on the metallic surface

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第2期6卷 449-467页

作者： zhiwei li Jianfu Zhang Zhongpeng Zheng Pingfa Feng Dingwen Yu Jianjian Wang State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Beijing Key Laboratory of Precision/Ultra-precision Manufacturing Equipments and Control Department of Mechanical EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Division of Advanced Manufacturing Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055People’s Republic of China

High-aspect-ratio metallic surface microstructures are increasingly demanded in breakthrough applications,such as high-performance heat transfer enhancement and surface plasmon ***,the fast and cost-effective fabrication of high-aspect-ratio microstructures on metallic surfaces remains challenging for existing *** study proposes a novel cutting-based process,namely elliptical vibration chiseling(EV-chiseling),for the high-efficiency texturing of surface microstructures with an ultrahigh aspect *** conventional cutting,EV-chiseling superimposes a microscale EV on a backward-moving *** tool chisels into the material in each vibration cycle to generate an upright chip with a high aspect ratio through material *** to the tool’s backward movement,the chip is left on the material surface to form a microstructure rather than falling *** one microstructure is generated in one vibration cycle,the process can be highly efficient using ultrafast(>1 kHz)tool vibration.A finite element analysis model is established to explore the process mechanics of ***,a mechanistic model of the microstructured surface generation is developed to describe the microstructures’aspect ratio dependency on the process ***,surface texturing tests are performed on copper to verify the efficacy of *** micro ribs with a spacing of 1–10μm and an aspect ratio of 2–5 have been successfully textured on *** with the conventional EV-cutting that uses a forward-moving tool,EV-chiseling can improve the aspect ratio of textured microstructure by up to 40 *** experimental results also verify the accuracy of the developed surface generation model of ***,the effects of elliptical trajectory,depth of cut,tool shape,and tool edge radius on the surface generation of micro ribs have been discussed.

关键词： metallic microstructure high aspect ratio backward-moving cutting vibration cutting chiseling material deformation

A novel strategy of tannery sludge disposal–converting into biochar and reusing for Cr(Ⅵ)removal from tannery wastewater

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 637-649页

作者： zhiwei li Di Yu Xingdong Wang Xuejiao liu Zhen Xu Yin Wang CAS Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control CAS Haixi Industrial Technology Innovation Center in BeilunNingbo 315830China Key Laboratory of Urban Environment and Health Ningbo Observatio

Tannery sludge with high chromium content has been identified as hazardous solid waste due to its potential toxic *** safety disposal and valorization of the tannery sludge remains a *** this study,the chromium stabilization mechanism was systematically investigated during chromium-rich tannery sludge was converted to biochar and the removal performance of the sludge biochar(SBC)for Cr(Ⅵ)from tannery wastewater was also *** results showed that increase in pyrolysis temperature was conductive to the stabilization of Cr and significant reduction of the proportion of Cr(Ⅵ)in *** was confirmed that the stabilization of chromium mainly was attributed to the embedding of chromium in the C matrix and the transformation of the chromium-containing substances from the amorphous Cr(OH)_(3)to the crystalline state,such as(FeMg)Cr_(2)O_(5).The biochar presented high adsorption capacity of Cr(Ⅵ)at low pH and the maximal theoretical adsorption capacity of SBC produced at 800°C can reach 352 mg Cr(Ⅵ)/g,the process of which can be well expressed by Langmuir adsorption isotherm and pseudo second order *** electrostatic effect and reduction reaction were dominantly responsible for the Cr(Ⅵ)adsorption by ***,this study provided a novel strategy for the harmless disposal and resource utilization for the solid waste containing chromium in leather industry.

关键词： Chromium-rich tannery sludge Pyrolysis Biochar Stabilizationmechanisms Cr(Ⅵ)adsorption

Role of 5-hydroxytryptamine type 3 receptors in the regulation of anxiety reactions

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第1期25卷 23-37页

作者： Yinan DU zhiwei li Yukui ZHAO Jing HAN Weiping HU Zhiqiang liU MOE Key Laboratory of Modern Teaching Technology Shaanxi Normal UniversityXi’an710062China

5-Hydroxytryptamine(5-HT)type 3 receptor(5-HT_(3)R)is the only type of ligand-gated ion channel in the 5-HT receptor *** the high permeability of Na+,K+,and Ca2+and activation of subsequent voltage-gated calcium channels(VGCCs),5-HT_(3)R induces a rapid increase of neuronal excitability or the release of neurotransmitters from axon terminals in the central nervous system(CNS).5-HT_(3)Rs are widely expressed in the medial prefrontal cortex(mPFC),amygdala(AMYG),hippocampus(HIP),periaqueductal gray(PAG),and other brain regions closely associated with anxiety *** have a bidirectional regulatory effect on anxiety reactions by acting on different types of cells in different brain regions.5-HT_(3)Rs mediate the activation of the cholecystokinin(CCK)system in the AMYG,and theγ-aminobutyric acid(GABA)“disinhibition”mechanism in the prelimbic area of the mPFC promotes anxiety by the activation of GABAergic intermediate inhibitory neurons(IINs).In contrast,a 5-HT_(3)R-induced GABA“disinhibition”mechanism in the infralimbic area of the mPFC and the ventral HIP produces anxiolytic effects.5-HT_(2)R-mediated regulation of anxiety reactions are also activated by 5-HT_(3)R-activated 5-HT release in the HIP and *** provides a theoretical basis for the treatment of anxiety disorders or the production of anxiolytic drugs by targeting 5-HT_(3)***,given the circuit specific modulation of 5-HT_(3)Rs on emotion,systemic use of 5-HT_(3)R agonism or antagonism alone seems unlikely to remedy anxiety,which deeply hinders the current clinical application of 5-HT_(3)R ***,the exploitation of circuit targeting methods or a combined drug strategy might be a useful developmental approach in the future.

关键词： 5-Hydroxytryptamine type 3 receptor(5-HT_(3)R) Anxiety Medial prefrontal cortex Amygdala Hippocampus Periaqueductal gray

A Multi-Baseline PolinSAR Forest Height Inversion Method Taking into Account the Model Ill-posed Problem

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 Geodesy and Geoinformation Science 2024年第3期7卷 42-56页

作者： liN Dongfang ZHU Jianjun li zhiwei FU Haiqiang liANG Ji ZHOU Fangbin ZHANG Bing Hunan Provincial Key Laboratory of Geo-Information Engineering in Surveying Mapping and Remote SensingHunan University of Science and TechnologyXiangtan 411201China School of Geosciences and Info-Physics Central South UniversityChangsha 410083China Hunan International Scientific and Technological Innovation Cooperation Base of Advanced Construction and Maintenance Technology of Highway Changsha University of Science&TechnologyChangsha 410114China School of Geomatics Liaoning Technical UniversityFuxin 123000China

Affected by the insufficient information of single baseline observation data,the three-stage method assumes the Ground-to-Volume Ratio(GVR)to be zero so as to invert the vegetation ***,this assumption introduces much biases into the parameter estimates which greatly limits the accuracy of the vegetation height ***-baseline observation can provide redundant information and is helpful for the inversion of ***,the similar model parameter values in a multi-baseline model often lead to ill-posed problems and reduce the inversion accuracy of conventional *** this end,we propose a new step-by-step inversion method applied to the multi-baseline ***,an adjustment inversion model is constructed by using multi-baseline volume scattering dominant polarization data,and the regularized estimates of model parameters are obtained by regularization ***,the reliable estimates of GVR are determined by the MSE(mean square error)analysis of each regularized parameter ***,the estimated GVR is used to extracts the pure volume coherence,and then the vegetation height parameter is inverted from the pure volume coherence by least squares *** experimental results show that the new method can improve the vegetation height inversion result *** inversion accuracy is improved by 26%with respect to the three-stage method and the conventional solution of *** of these have demonstrated the feasibility and effectiveness of the new method.

关键词： multi-baseline vegetation height GVR PolinSAR ill-posed problem

Synthesis,disorder and Ising anisotropy in a new spin liquid candidate PrMgAl_(11)O_(19)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Materials Futures 2024年第3期3卷 148-156页

作者： Yantao Cao Huanpeng Bu Zhendong Fu Jinkui Zhao Jason S Gardner Zhongwen Ouyang Zhaoming Tian zhiwei li Hanjie Guo Key Lab for Magnetism and Magnetic Materials of the Ministry of Education Lanzhou UniversityLanzhou 730000People’s Republic of China Songshan Lake Materials Laboratory DongguanGuangdong 523808People’s Republic of China Institute of Physics Chinese Academy of SciencesBeijing 100190People’s Republic of China Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTN 37831United States of America School of Physics and Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhan 430074People’s Republic of China

Here we report the successful synthesis of large single crystals of triangular frustrated PrMgAl_(11)O_(19)using the optical floating zone *** crystal x-ray diffraction(XRD)measurements unveiled the presence of quenched disorder within the mirror plane,specifically~7%of Pr ions deviating from the ideal 2d site towards the 6h *** susceptibility measurements revealed an Ising anisotropy with the c-axis being the easy *** a large spin–spin interaction that develops below~10 K and considerable site disorder,the spins do not order or freeze down to at least 50 *** availability of large single crystals offers a distinct opportunity to investigate the exotic magnetic state on a triangular lattice with an easy axis out of the plane.

关键词： spin liquid disorder frustration triangular lattice Ising anisotropy

Co and postseismic fault slip models of the 2022 M_(W)6.7 Menyuan earthquake reveal conjugated faulting tectonics at the central section of the Lenglongling fault

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Science 2024年第4期37卷 277-303页

作者： Zilong He Wenbin Xu zhiwei li Lei Xie Guangcai Feng Nan Fang Xiaoge liu Kai Sun Zhidan Chen Zhihui Zhu School of Geosciences and Info-Physics Central South UniversityChangsha 410083China Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring Central South UniversityChangsha 410083China School of Civil Engineering Central South UniversityChangsha 410083China

The 2022 M_(W)6.7 Menyuan earthquake ruptured the western end of the Tianzhu seismic gap,providing an opportunity to study the regional seismogenic characteristics and seismic *** we use interferometric synthetic aperture radar(InSAR)and seismic data to study the mainshock rupture,early afterslip and the second largest aftershock of the 2022 Menyuan earthquake *** modeling results show that the mainshock ruptured the Lenglongling fault and the Tuolaishan fault with a maximum slip of~3 *** postseismic transient deformation occurred at the center of the Lenglongling *** afterslip modeling reveals that the majority of afterslip occurred in the deeper part of the Lenglongling fault.A high-angle conjugated faulting event is found at the middle section of the Lenglongling *** use the stress inversion to investigate the possible triggering mechanism of the conjugated rupture *** results indicate the maximum principal stress direction is in~222°,forming a~22°angle between the conjugated fault of second largest aftershock and the *** calculated normal stress changes indicate the region is within a pull-apart stress field,which favors such a conjugated rupturing *** study will help understand the rupture behavior of such kind of conjugated fault in other regions.

关键词： coseismic displacement and slip postseismic deformation and afterslip conjugate rupture coulomb stress change stress inversion

Electronic Correlation and Pseudogap-like Behavior of High-Temperature Superconductor La_(3)Ni_(2)O_(7)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第8期41卷 82-93页

作者： Yidian li Xian Du Yantao Cao Cuiying Pei Mingxin Zhang Wenxuan Zhao Kaiyi Zhai Runzhe Xu Zhongkai liu zhiwei li Jinkui Zhao Gang li Yanpeng Qi Hanjie Guo Yulin Chen Lexian Yang State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Key Lab for Magnetism and Magnetic Materials of the Ministry of Education Lanzhou UniversityLanzhou 730000China Songshan Lake Materials Laboratory Dongguan 523808China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China ShanghaiTech Laboratory for Topological Physics Shanghai 200031China Shanghai Key Laboratory of High-Resolution Electron Microscopy ShanghaiTech UniversityShanghai 201210China Department of Physics Clarendon LaboratoryUniversity of OxfordParks RoadOxford OX13PUUK Frontier Science Center for Quantum Information Beijing 100084China

High-temperature superconductivity(HTSC)remains one of the most challenging and fascinating mysteries in condensed matter ***,superconductivity with transition temperature exceeding liquid-nitrogen temperature is discovered in La_(3)Ni_(2)O_(7) at high pressure,which provides a new platform to explore the unconventional *** this work,using high-resolution angle-resolved photoemission spectroscopy and ab initio calculation,we systematically investigate the electronic structures of La_(3)Ni_(2)O_(7) at ambient *** experiments are in nice agreement with ab initio calculations after considering an orbital-dependent band renormalization *** strong electron correlation effect pushes a flat band of d_(z^(2))𝑧2 orbital component below the Fermi level(E_(F)),which is predicted to locate right at E_(F) under high ***,the d_(x^(2)−y^(2)) band shows pseudogap-like behavior with suppressed spectral weight and diminished quasiparticle peak near E_(F).Our findings provide important insights into the electronic structure of La_(3)Ni_(2)O_(7),which will shed light on understanding of the unconventional superconductivity in nickelates.

关键词： effect superconductivity orbital

基于CT图像的水泥稳定RAP材料细观结构研究

在线全文

学校读者我要写书评

暂无评论

材料导报 2024年第1期38卷 66-71页

作者：阳虎单丽岩李志伟哈尔滨工业大学交通科学与工程学院哈尔滨150090

研究沥青混合料回收料(RAP)掺加对混合料组成与结构特性的影响,可为其应用在路面结构层以及材料参数设计提供理论支撑。基于X-ray CT与图像处理技术,提出了一种可区分新旧集料的冷再生混合料细观结构识别方法,分析了RAP团粒、旧集料与... 详细信息

研究沥青混合料回收料(RAP)掺加对混合料组成与结构特性的影响,可为其应用在路面结构层以及材料参数设计提供理论支撑。基于X-ray CT与图像处理技术,提出了一种可区分新旧集料的冷再生混合料细观结构识别方法,分析了RAP团粒、旧集料与新集料的细观特征的差异,研究了RAP的掺加对水泥稳定材料细观结构的影响。结果表明:提出的细观结构识别方法可准确识别水泥稳定RAP材料断面图像中的空隙、砂浆、新集料与旧集料四类区域,完整地保留新旧集料的原始轮廓、大小与形状等信息;RAP团粒中分布较多初始微细裂缝,且旧集料扁平比与棱角性系数均大于新集料;RAP的掺加一方面增加了再生混合料中体积小于0.01 mm3的微空隙与大于100 mm3的大空隙数量,导致材料的密实度降低;另一方面也增加了材料的沥青砂浆含量,提高了再生混合料的平均砂浆膜厚度,使混合料骨架内部力传导更均匀;提高水泥稳定RAP材料中石屑与碎石比例,可使材料的平均空隙体积减小、平均砂浆膜厚度增大,从而改善再生混合料的骨架填充状态。

关键词： RAP 水泥稳定材料 X-ray CT 细观结构冷再生技术