检索结果-南通市图书馆

Resin Matrix Shear Band and Its Special Effect on Stress Concentration of Fiber Composites

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2014年第6期32卷 703-710页

作者： guo-wei Zhu Feng-de Ma 贾玉玺 Peng Qu yun-li guo Xiao-chen Sun Key Laboratory for liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education) Shandong University

A constitutive model is constructed to consider the resin matrix post-yield softening and progressive hardening behaviors. A user-defined material mechanical behavior （UMAT） subroutine is created, then the non-linear three-dimensional finite element analysis on the tensile processes of multi-fiber composites is conducted. The approximate 45° shear bands emanating from the matrix crack tip are found, being coincided with the experimental observations. The shear stress on the adjacent intact fiber/matrix interface is strongly influenced by the shear band and thus the stress concentration factor （SCF） changes obviously in the adjacent fibers. The distinct stress redistribution in the adjacent intact fibers implies the significant effect of the shear bands on the progressive fiber fracture initiation. As the inter-fiber spacing increases, the peak value of the SCF in the adjacent intact fiber decreases, whereas the overload zone becomes wider. The research has provided a helpful tool to evaluate the failure of fiber composites and optimize the composite performance through the proper selection of resin matrix properties and fiber volume fraction.

关键词： Fiber composite Stress concentration Shear band Fiber volume fraction Theory and modeling.

Investigation of potential strategies to control malt-induced premature yeast flocculation

在线全文

学校读者我要写书评

暂无评论

Systems Microbiology and Biomanufacturing 2021年第2期1卷 193-199页

作者： li-yun guo Xin Xie Nan Zhao Mei Wang Zhi-Ping lin Yu-Mei Song Feng-Chao Jia Beijing Yan Jing Brewery Company Ltd Beijing 101300China Key Laboratory of Beijing Yanjing Beer Brewing Technology Beijing 101300China Yanjing Research Center No.9Shuanghe RoadShunyi DistrictBeijing 101300China

Premature yeast flocculation(PYF)during beer fermentation is an undesired event by which yeast flocculate too early and heavily before the wort nutrition is *** PYF can be a major financial detriment to brewers,the conditions that trigger it and the chemical composition of PYF are poorly *** chromatography-mass spectrometry results from this study indicated that purified malt PYF factor consisted of numerous polysaccharides;however,no protein was *** concentrations of PYF promoted further yeast flocculation,which in turn decreased the rate of fermentation and increased acetaldehyde content of the *** factors were found to be derived primarily from malt husks and factors such as microbial content of the water used for germination,mixing malts with different PYF values,and presence of tannic acid were all found to influence the rate of yeast *** from this study may be beneficial in developing PYF prevention and control measures that can be applied to future brewing strategies.

关键词： Premature yeast flocculation Malt microbial contamination PYF factors Beer fermentation

Advances in Graphene‑Based Electrode for Triboelectric Nanogenerator

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

Nano-Micro Letters 2025年第1期17卷 378-403页

作者： Bin Xie Yuanhui guo yun Chen Hao Zhang Jiawei Xiao Maoxiang Hou Huilong liu li Ma Xin Chen Chingping Wong State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006People’s Republic of China School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006People’s Republic of China School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

With the continuous development of wearable electronics,wireless sensor networks and other micro-electronic devices,there is an increasingly urgent need for miniature,flexible and efficient nanopower generation *** nanogenerator(TENG)technology can convert small mechanical energy into electricity,which is expected to address this *** the core component of TENG,the choice of electrode materials significantly affects its *** metal electrode materials often suffer from problems such as durability,which limits the further application of ***,as a novel electrode material,shows excellent prospects for application in TENG owing to its unique structure and excellent electrical *** review systematically summarizes the recent research progress and application prospects of TENGs based on graphene *** precision processing methods of graphene electrodes are introduced,and the applications of graphene electrode-based TENGs in various scenarios as well as the enhancement of graphene electrodes for TENG performance are *** addition,the future development of graphene electrode-based TENGs is also prospectively discussed,aiming to promote the continuous advancement of graphene electrode-based TENGs.

关键词： Triboelectric nanogenerator Precision processing Graphene electrode Self-powered sensor

A Wind Tunnel Experimental Study on the Wake Characteristics of a Horizontal Axis Wind Turbine

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期34卷 145-158页

作者： guo Xingduo li Yinran li Rennian MA Yulong WEI Kui College of Energy and Power Engineering Lanzhou University of Technology Key Laboratory of Fluid Machinery and Systems Gansu Provincial Technology Centre for Wind Turbines

The characteristics of wind turbine wakes are influenced by multiple factors,including the atmospheric boundary layer(ABL) wind and wind turbine operating conditions(e.g.,tip speed ratio and yaw angle).In this study,two types of ABL winds with different velocity gradients and turbulence intensities are generated in a wind tunnel through configurations of spires,baffles,and various numbers of roughness elements.A wind turbine with a rotor diameter of 0.8 m and a hub height of 0.6 m is tested under varying tip speed ratios,yaw angles,and ABL wind *** results indicate that the streamwise velocity deficit in the near-wake region becomes more pronounced with an increase in the tip speed ratio,while the far-wake velocity deficit remains largely unaffected by changes in the tip speed *** the yaw angle increases,the wake deflection becomes more prominent and the wake narrows;the offset of the wake center at various downstream positions grows linearly,reaching a maximum value of approximately half the rotor ***,the turbulence level and influence range in the wake region are reduced when the turbine is *** ABL wind conditions,high turbulence intensity in the incoming flow accelerates wake recovery,and the Reynolds stress at different lateral positions tends to become consistent with increasing longitudinal ***,turbulence has a significant impact on the meandering characteristics of the wind turbine wake,with greater fluctuations in the wake center observed under higher turbulence ***,this study provides insights that could inform the optimal operation of wind farms.

关键词： horizontal axis wind turbine turbulence wind tunnel experiment wind turbine wake

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

明代中国经济的产权分析与中欧比较研究

中南财经政法大学学报 2007年第5期 131-135页

作者：李国运武汉大学经济与管理学院湖北武汉430072

资本市场的萌芽和产生是商品经济的发展水平、社会化大生产状况和信用制度的成熟程度等三个因素共同促成的结果。在14-16世纪，中国和欧洲的基本条件相当，但欧洲地区出现了世界最早的资本市场，并逐步发展成为新的世界经济中心，而当... 详细信息

资本市场的萌芽和产生是商品经济的发展水平、社会化大生产状况和信用制度的成熟程度等三个因素共同促成的结果。在14-16世纪，中国和欧洲的基本条件相当，但欧洲地区出现了世界最早的资本市场，并逐步发展成为新的世界经济中心，而当时经济同样发达，并具有悠久文明史的古老中国却不仅没有产生资本市场，反而日渐衰落。本文从产权经济学的视角对明代中国和欧洲的经济发展状况和产权制度进行了比较研究，论证了14-16世纪的中国不可能出现资本市场的历史必然性。

关键词：资本市场产权会计史经济史

在线全文

学校读者我要写书评

暂无评论

中国资本市场监管体系的若干问题

中南财经政法大学学报 2006年第6期 50-53页

作者：李国运武汉大学经济与管理学院湖北武汉430072

中国资本市场目前的诸多问题都与其监管体制的缺陷有关。本文通过对中国资本市场监管体系中的法律监管系统、行政监管系统和行业自律系统三个子系统进行分析,找出影响中国资本市场监管效率的八大主要问题,并有针对性的提出了强化法律监... 详细信息

中国资本市场目前的诸多问题都与其监管体制的缺陷有关。本文通过对中国资本市场监管体系中的法律监管系统、行政监管系统和行业自律系统三个子系统进行分析,找出影响中国资本市场监管效率的八大主要问题,并有针对性的提出了强化法律监管,改革行政监管体制,发挥自律机构的自律功能的建议。

关键词：资本市场监管体制会计监管

在线全文

学校读者我要写书评

暂无评论

风力发电机齿轮箱加速疲劳试验技术分析

重庆大学学报（自然科学版） 2009年第11期32卷 1252-1256页

作者：李国云秦大同攀枝花学院机电工程学院四川攀枝花617000 重庆大学机械传动国家重点实验室重庆400030

针对风力发电机齿轮箱的高可靠性要求,提出了一种加速疲劳试验技术方法来验证齿轮箱的疲劳可靠性。根据齿轮箱的设计载荷谱,推导了其主要零件在寿命周期内的等效载荷和应力循环次数;应用Miner线性累积疲劳损伤理论,计算了齿轮和轴承在... 详细信息

针对风力发电机齿轮箱的高可靠性要求,提出了一种加速疲劳试验技术方法来验证齿轮箱的疲劳可靠性。根据齿轮箱的设计载荷谱,推导了其主要零件在寿命周期内的等效载荷和应力循环次数;应用Miner线性累积疲劳损伤理论,计算了齿轮和轴承在设计寿命周期内的疲劳损伤度;采用线性强化载荷谱的方法建立了风电齿轮箱加速疲劳试验载荷谱,结果在大约800 h左右就验证了齿轮箱的疲劳可靠性。

关键词：风力发电齿轮箱加速疲劳试验齿轮损伤度可靠性

The detection, extraction and parameter estimation of extreme-mass-ratio inspirals with deep learning

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 86-96页

作者： Qianyun yun Wen-Biao Han Yi-Yang guo He Wang Minghui Du Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences Shanghai Astronomical Observatory Chinese Academy of Sciences School of Physics and Astronomy Shanghai Jiao Tong University School of Astronomy and Space Science University of Chinese Academy of Sciences Taiji Laboratory for Gravitational Wave Universe (Beijing/Hangzhou) University of Chinese Academy of Sciences Lanzhou Center for Theoretical Physics Key Laboratory of Theoretical Physics of Gansu Province Key Laboratory of Quantum Theory and Applications of MoE Lanzhou University Institute of Theoretical Physics & Research Center of Gravitation Lanzhou University International Centre for Theoretical Physics Asia-Pacific (ICTP-AP) University of Chinese Academy of Sciences (UCAS) Center for Gravitational Wave Experiment National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences

One of the primary goals of space-borne gravitational wave detectors is to detect and analyze extreme-mass-ratio inspirals(EMRIs). This task is particularly challenging because EMRI signals are complex, lengthy, and faint. In this work, we introduce a2-layer convolutional neural network(CNN) approach to detect EMRI signals for space-borne detectors, achieving a true positive rate(TPR) of 96.9% at a 1% false positive rate(FPR) for signal-to-noise ratio(SNR) from 50 to 100. Especially, the key intrinsic parameters of EMRIs such as the mass, spin of the supermassive black hole(SMBH) and the initial eccentricity of the orbit can also be inferred directly by employing a neural network. The mass and spin of the SMBH can be determined at 99% and 92% respectively. This will greatly reduce the parameter spaces and computing cost for the following Bayesian parameter *** model also has a low dependency on the accuracy of the waveform model. This study underscores the potential of deep learning methods in EMRI data analysis, enabling the rapid detection of EMRI signals and efficient parameter estimation.

关键词： gravitational wave EMRIs deep-learing

Sequence-activated chemiluminescence probes: programmable illumination for high-contrast in vivo sensing and imaging

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 26-34页

作者： Yutao Zhang Juan li Wei-Hong Zhu Zhiqian guo Shanghai Key Laboratory of Functional Materials Chemistry Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Institute of Fine Chemicals School of Chemistry and Molecular Engineering East China University of Science and Technology State Key Laboratory of Bioreactor Engineering Shanghai Frontier Science Research Base of Optogenetic Techniques for Cell MetabolismEast China University of Science & Technology

Sequence-activated chemiluminescence(CL) technique offers a unique approach to detecting specific biomolecules or cellular events with high sensitivity and spatial resolution. The fundamental principle behind sequence-activated CL probes involves tailoring highly-controllable CL signals in response to specific sequences or events of interest, thus enabling high-contrast signals under complex physiological conditions. This sequential activation could be triggered by enzymes, reactive oxygen species(ROS), biothiols or changes in the microenvironment. These unique sequence-activated CL probes bestow several advantages, including minimal background, deep-tissue penetration, and the ability of non-invasive or minimally invasive detection. The sequence-activated CL techniques represent a significant advancement in molecular imaging and diagnostics. In this mini-review, we focus on the latest developments in sequential CL probes, addressing the technical challenges and discussing the future trajectory by harnessing CL signaling and molecular recognition.

关键词： chemiluminescnece sequence-activation in-vivo bioimaging cyclic peroxide