检索结果-南通市图书馆

Aerodynamic Optimization and Flow Mechanism for a Compressor Cascade at Low Reynolds Number

Journal of Thermal Science 2025年第1期34卷 92-109页

作者： LI lin ZHANG Jianshe CHEN Caiyan TAN Wei ZHANG Yanfeng Key Laboratory of Light-Duty Gas-Turbine Institute of Engineering ThermophysicsChinese Academy of Sciences University of Chinese Academy of Sciences National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine

Low-Reynolds-number effect is an important factor affecting the performance of compressors and other main components of high-altitude long-endurance unmanned aerial *** improve the flow condition and reduce flow loss under the condition of high altitude and low Reynolds number(Re),this paper proposes an optimization process based on a surrogate model,which combines the class-shape transformation method(CST),the Latin hypercube sampling(LHS) method,the light gradient-boosting machine algorithm(LightGBM),and a genetic algorithm(GA) to optimize a high-subsonic compressor *** surrogate model is verified to be accurate and can be used in the optimization *** accuracy of the GA is higher than the other algorithms under common test *** optimization results are verified by numerical simulation,and the flow differences before and after optimization are compared,especially the flow within the boundary *** changing the blade shape,the optimization process adjusts the loading distribution to delay the transition of the optimized blade on the suction surface,which changes the turbulent reattachment in the laminar separation bubble(LSB) into laminar ***,the mixing loss induced by the turbulent reattachment of the LSB and the wake loss of turbulent separation at the trailing edge are significantly reduced,and the performance of the compressor profile is finally *** addition,turbulent separation of the optimized profile is delayed reducing the range of the wake region on the suction *** this optimization process,the reduction of total pressure loss coefficient at Re of 2.5×10～5,3.5×10～5,and 4.5×10～5 are 16.32%,20.76%,and 22.16%,respectively.

关键词： Reynolds number

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Elastic responses of underground circular arches considering dynamic soil-structure interaction:A theoretical analysis

引用

Acta Mechanica Sinica 2013年第1期29卷 110-122页

作者： Hai-long Chen Feng-Nian Jin Hua-lin Fan PLA University of Science and Technology Key Laboratory of Bridge-structure Engineering Chongqing Jiaotong University Laboratory of Structural Analysis for Defense Engineering and Equipment College of Mechanics and Materials Hohai University Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province Lanzhou Jiaotong University

Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibration of circular arches subjected to subsurface denotation forces is obtained. The dynamic soil-structure interaction is considered with the introduction of an interfacial damping between the structure element and the surrounding soil into the equa- tion of motion. By neglecting the influences of shear, rotary inertia and tangential forces and assuming the arch incompressible, the equations of motion of the buried arches were set up. Analytical solutions of the dynamic responses of the protective arches were deduced by means of modal super- position. Arches with different opening angles, acoustic impedances and rise-span ratios were analyzed to discuss their influences on an arch. The theoretical analysis suggests blast loads for elastic designs and predicts the potential failure modes for buried protective arches.

关键词： Underground protective arches - Dynamic soilstructure interaction Dynamic responses Analytical solution

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

Dynamical classification of topological quantum phases

引用

Science Bulletin 2018年第21期63卷 1385-1391页

作者： lin Zhang long Zhang Sen Niu Xiong-Jun Liu International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen 518055China

Topological phase of matter is now a mainstream of research in condensed matter physics, of which the classification, synthesis, and detection of topological states have brought excitements over the recent decade while remain incomplete with ongoing challenges in both theory and experiment. Here we propose to establish a universal non-equilibrium characterization of the equilibrium topological quantum phases classified by integers, and further propose the high-precision dynamical schemes to detect such states. The framework of the dynamical classification theory consists of basic theorems. First, we uncover that classifying a d-dimensional(dD) gapped topological phase of generic multibands can reduce to a(d-1)D invariant defined on so-called band inversion surfaces(BISs), rendering a bulk-surface duality which simplifies the topological characterization. Further, we show in quenching across phase boundary the(pseudo) spin dynamics to exhibit unique topological patterns on BISs, which are attributed to the post-quench bulk topology and manifest a dynamical bulk-surface correspondence. For this the topological phase is classified by a dynamical topological invariant measured from an emergent dynamical spintexture field on the BISs. Applications to quenching experiments on feasible models are proposed and studied, demonstrating the new experimental strategies to detect topological phases with high feasibility. This work opens a broad new direction to classify and detect topological phases by non-equilibrium quantum dynamics.

关键词： Quench dynamics Topological quantum phase Band inversion surface Bulk-surface duality Dynamical topological invariant Ultracold atoms Synthetic gauge field

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

Real-time analysis and prediction of shield cutterhead torque using optimized gated recurrent unit neural network

引用

Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1232-1240页

作者： Song-Shun lin Shui-long Shen Annan Zhou Department of Civil Engineering School of Naval ArchitectureOceanand Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Key Laboratory of Intelligent Manufacturing Technology Department of Civil and Environmental EngineeringCollege of EngineeringShantou UniversityShantou515063China Discipline of Civil and Infrastructure School of EngineeringRoyal Melbourne Institute of Technology(RMIT)MelbourneVictoria 3001Australia Department of Civil and Environmental Engineering National University of Singapore117576Singapore

An accurate prediction of earth pressure balance(EPB)shield moving performance is important to ensure the safety tunnel excavation.A hybrid model is developed based on the particle swarm optimization(PSO)and gated recurrent unit(GRU)neural *** is utilized to assign the optimal hyperparameters of GRU neural *** are mainly four steps:data collection and processing,hybrid model establishment,model performance evaluation and correlation *** developed model provides an alternative to tackle with time-series data of tunnel *** from that,a novel framework about model application is performed to provide guidelines in practice.A tunnel project is utilized to evaluate the performance of proposed hybrid *** indicate that geological and construction variables are significant to the model *** analysis shows that construction variables(main thrust and foam liquid volume)display the highest correlation with the cutterhead torque(CHT).This work provides a feasible and applicable alternative way to estimate the performance of shield tunneling.

关键词： Earth pressure balance(EPB)shield tunneling Cutterhead torque(CHT)prediction Particle swarm optimization(PSO) Gated recurrent unit(GRU)neural network

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

Sedimentation of short cylindrical pollutants with mechanical contacts

引用

Journal of Environmental Sciences 2005年第6期17卷 906-911页

作者： lin Jian-zhong WANG Ye-long ZHANG Wei-feng Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China Institute of Marine and Coastal Sciences Rutgers University New Brunswick New Jersey USA

Lattice Boltzmann method and elastic particle collision model were used to investigate the sedimentation of short cylindrical pollutant particles with mechanical contacts for varying bulk number density ε and terminal Reynolds number ReT. The corresponding experiments were performed as a comparison. The clusters of pollutant particles with an inverted “T” structure were observed, the pollutant particles for high ε and large ReT scattered wider than that for low ε and small ReT. The sedimentation velocities increased suddenly at the initial stage, then decreased drastically, after that swayed around and approached to a steady value. The time to steady state did not depend on ε and ReT. The effect of particle interactions was to hinder the average sedimentation velocity, and hindrance was directly proportional to ε. The orientation distributions of pollutant particles depended on ReT and ε, especially on the former. Both the standard deviations of vertical and horizontal velocity, the former was larger than the latter, were nearly independent on ε and ReT.

关键词： cylindrical pollutant particles sedimentation lattice-Boltzmann simulation experiment mechanical contact

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

Mechanism study of Cu(Ⅱ) adsorption from acidic wastewater by ultrasonic-modified municipal solid waste incineration fly ash

引用

Chinese Journal of Chemical Engineering 2024年第3期67卷 157-165页

作者： Shunda lin Yang Lu lin Zheng ling long Xuguang Jiang Jianhua Yan State Key Laboratory of Clean Energy Utilization Institute for Thermal Power EngineeringZhejiang UniversityHangzhou 310027China Zhejiang University Qingshanhu Energy Research Center Hangzhou 310027China Hangzhou Xiaoshan Jinjiang Green Energy Co. Ltd.XiaoshanHangzhou 310000China

High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(MSWI) fly ash for Cu(Ⅱ) adsorption to achieve the purpose of “treating waste by waste.” The effects of p H, adsorption time, initial concentration, and temperature on the modified MSWI fly ash’s adsorption efficiency were systematically studied in this article. The adsorption performance of the modified MSWI fly ash can be enhanced by the ultrasonic modification. At pH = 2, 3 and 4, the adsorption capacity of the modified MSWI fly ash for Cu(Ⅱ) increased by 2.7, 1.9 and 1.2 times, respectively. Furthermore, it was suggested that the adsorption process of the modified MSWI fly ash can be better simulated by the pseudo-second-order kinetic model, with a maximum adsorption capacity calculated by the Langmuir model of 24.196 mg.g-1. Additionally, the adsorption process is spontaneous,endothermic, and chemisorption-dominated from the thermodynamic studies(ΔH and ΔS > 0, ΔG < 0).Finally, the enhanced adsorption performance of the modified MSWI fly ash for Cu(Ⅱ) may be attributed to electrostatic interaction and chelation effects.

关键词： Ultrasound MSWI fly ash Cu(Ⅱ) Wastewater Adsorption

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

Memory effect evaluation based on transmission matrix calculation

引用

Chinese Physics B 2019年第7期28卷 259-268页

作者： Ming Li long-Jie Fang lin Pang College of Physics Sichuan University

The memory effect is a type of auto correlation observed in linear systems, which is widely used to control scattered light through thin scattering *** show that there exists a strong correlation among the optimized phase distributions of adjacent focal points in focusing through scattering *** numeric simulation and experiment indicate that within the memory effect, the phase difference between the two adjacent focal points shows an optical phase fringe pattern, and the closer the adjacent focal points are, the wider the fringe pattern will be, corresponding to the tilting of a plane wave phase added onto the acquired optical phase distribution at the focal *** effect can be utilized for achieving optimal phase distributions of focal point scanning without optical phase evaluation via the experiment, which has great potential application in imaging through the scattering medium.

关键词： scattering media phase modulation optical memory effect focal point

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

客户端独立的IP地理定位研究综述

引用

软件学报 2025年第1期36卷 321-340页

作者：林金磊李城龙宋光磊樊琳娜王之梁杨家海清华大学网络科学与网络空间研究院中关村实验室国防科技大学信息通信学院

准确、快速地获取IP地理定位信息对于各种网络应用而言至关重要. IP地理定位指将互联网实体的IP地址转换为其地理位置的技术.然而,互联网规模的迅速扩大和互联网应用的快速发展,给IP地理定位研究带来了巨大的挑战.首先,复杂的网络结构... 详细信息

准确、快速地获取IP地理定位信息对于各种网络应用而言至关重要. IP地理定位指将互联网实体的IP地址转换为其地理位置的技术.然而,互联网规模的迅速扩大和互联网应用的快速发展,给IP地理定位研究带来了巨大的挑战.首先,复杂的网络结构和网络环境导致IP定位技术的精确度远远无法满足实际的应用需求.其次,IP地理定位在各个领域的作用日益凸显,如何精准、高效、可靠地计算互联网主机的地理位置正在成为各行关注的焦点.因此,通过设备的IP地址对其进行地理定位以支撑复杂的上层应用尤为重要.自2001年以来,学术界和工业界围绕上述问题开展了大量的研究.系统地梳理客户端独立的IP地理定位方面的相关工作,系统地整理基于网络测量的IP地理定位研究分类方法.根据定位数据是否由主动测量产生,将相关研究分为主动的IP定位技术、被动的IP定位技术和主被动结合的IP定位技术.进一步,对每一类方法进行更细粒度的分类并分析其主要的优缺点.在此基础上,总结IP地理定位领域的最新进展和研究挑战,并展望其未来发展方向.

关键词：网络测量 IP地理定位地理定位地标

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rice seed storage proteins:Biosynthetic pathways and the effects of environmental factors

引用

Journal of Integrative Plant Biology 2021年第12期63卷 1999-2019页

作者： Wei He long Wang Qinlu lin Feng Yu National Engineering Laboratory for Rice and By-product Deep Processing Central South University of Forestry and TechnologyChangsha 410004China College of Biology State Key Laboratory of Chemo/Biosensing and Chemometricsand Hunan Province Key Laboratory of Plant Functional Genomics and Developmental RegulationHunan UniversityChangsha 410082China

Rice(Oryza sativa L.)is the most important food crop for at least half of the world’s *** to improved living standards,the cultivation of high-quality rice for different purposes and markets has become a major *** quality is determined by the presence of many nutritional components,including seed storage proteins(SSPs),which are the second most abundant nutrient components of rice grains after *** SSP biosynthesis requires the participation of multiple organelles and is influenced by the external environment,making it challenging to understand the molecular details of SSP biosynthesis and improve rice protein *** this review,we highlight the current knowledge of rice SSP biosynthesis,including a detailed description of the key molecules involved in rice SSP biosynthetic processes and the major environmental factors affecting SSP *** effects of these factors on SSP accumulation and their contribution to rice quality are also discussed based on recent *** recent knowledge suggests not only new research directions for exploring rice SSP biosynthesis but also innovative strategies for breeding high-quality rice varieties.

关键词： globulin glutelin high temperature nitrogen fertilizer prolamine rice seed storage proteins

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

Realistic interpretation of quantum mechanics and encounter-delayed-choice experiment

引用

Science China(Physics,Mechanics & Astronomy) 2018年第3期61卷 10-17页

作者： GuiLu long Wei Qin Zhe Yang Jun-lin Li State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua University Beijing 100084 China Innovative Center of Quantum Matter Beijing 100084 China Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China

In this paper, a realistic interpretation(REIN) of the wave function in quantum mechanics is briefly presented. We demonstrate that in the REIN, the wave function of a microscopic object is its real existence rather than a mere mathematical ***, the quantum object can exist in disjointed regions of space just as the wave function is distributed, travels at a finite speed, and collapses instantly upon a measurement. Furthermore, we analyze the single-photon interference in a Mach-Zehnder interferometer(MZI) using the REIN. Based on this, we propose and experimentally implement a generalized delayed-choice experiment, called the encounter-delayed-choice experiment, where the second beam splitter is decided whether or not to insert at the encounter of two sub-waves along the arms of the MZI. In such an experiment, the parts of the sub-waves, which do not travel through the beam splitter, show a particle nature, whereas the remaining parts interfere and thus show a wave nature. The predicted phenomenon is clearly demonstrated in the experiment, thus supporting the REIN idea.

关键词： wave function realistic interpretation Mach-Zehnder interferometer wave-particle duality

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：