检索结果-内蒙古大学图书馆

International Conference on (ICEPT) Electronic Packaging Technology

作者： Shun Wang Yan Zhang Yifeng Fu Johan Liu Xiaojing Wang Zhaonian Cheng Key Laboratory of Advanced Display and System Applications Ministry of Education SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden School of Mechatronics Engineering and Automation Shanghai University Shanghai China

Micro-channels are generally regarded as an effective method for the heat transfer in electronic products, and much effort has been put into improving their capacities. At the same time, carbon nanotubes have shown great potential in the field of heat transfer. This paper focuses on the microchannel heat sinks combined with carbon nanotubes. A series of 3D models had been created, and the heat transfer characteristics were studied. Two kinds of numerical model were carried out by using Fluent. One model contained the whole micro-channel cooler structure, and the other was a simplified model with only one channel taken into simulation. A comparison of results by the two models indicates a 19.5% variation in the maximum temperature on the fins. Furthermore, five micro-channel cooler structures were constructed with different fin widths. The simulation results showed that with the decrease in the fin width, heat transfer ability was improved. This is attributed to the anisotropic thermal conductivity of the fin arrays.

关键词： Heat sinks Heat transfer Thermal conductivity Carbon nanotubes Heat engines Thermal expansion Computational modeling Laboratories displays Mechatronics

来源：评论

学校读者我要写书评

暂无评论

Vibration and buckling of a carbon nanotube inserted with a carbon chain

Vibration and buckling of a carbon nanotube inserted with a ...

引用

International Conference on (ICEPT) Electronic Packaging Technology

作者： Zhili Hu X.M. Guo Johan Liu Key Laboratory of Advanced Display and System Applications Ministry of Education & SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University China SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden

An elastic string-elastic shell model is developed to study vibration behaviors of a carbon nanowire. The present model predicts that non-coaxial vibration between the C-chain and the innermost tube does not occur due to negligible bending rigidity of the C-chain. In addition, it is found that the C-chain has most significant effect on the lowest frequency associated with radial vibration mode for circumferential wave-number 2 (n=2). In particular, the effect of the C-chain on axisymmetric radial breathing frequencies (n=0) predicted by the present model is found to be in reasonable agreement with known experimental and modeling results available in the literature.

关键词： Electron tubes Mathematical model Vibrations Equations Strain Carbon Force

来源：评论

学校读者我要写书评

暂无评论

Stability and Neimark-Sacker bifurcation analysis for single gene discrete system with delay

Stability and Neimark-Sacker bifurcation analysis for single...

引用

Chinese Control Conference

作者： Feng Liu Qicheng Mei Fenglan Sun Xinmei Wang Hua O. Wang Hubei key Laboratory of Advanced Control and Intelligent Automation for Complex Systems Wuhan China School of Automation China University of Geosciences Wuhan China Research Center of System Theory and Application Chongqing University of Posts and Telecommunications Chongqing China Department of Mechanical Engineering Boston University Boston MA USA

The network structure and functional properties of gene regulatory system and their relationships arc an important research field in systems biology. In this paper, a new improved model is proposed based on the study of gene expression process. The model takes into account the effect of protein concentration on the gene expression, so as to obtain a new bifurcation point and improve the performance of the system. The validity of the model is verified by theoretical analysis and data simulation.

关键词： Mathematical model Proteins Stability analysis Bifurcation Biological system modeling Delays RNA

来源：评论

学校读者我要写书评

暂无评论

Image Coding and Compression Method Based on Semantics of Pixels for Semantic Communication

Image Coding and Compression Method Based on Semantics of Pi...

引用

IEEE International Conference on Communications in China Workshops (ICCC)

作者： Qizheng Sun Caili Guo Rui Tang Chuanhong Liu Yufeng Zhang Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications School of Information and Communication Engineering Beijing China Beijing Laboratory of Advanced Information Networks Beijing University of Posts and Telecommunications School of Information and Communication Engineering Beijing China China Telecom Dict Application Capability Center Beijing University of Posts and Telecommunications

ISBN: (数字)9798350377675

ISBN: (纸本)9798350377682

Semantic image transmission is promising for both image reconstruction or downstream task execution. However, it is still challenging to simultaneously achieve pleasing visual clarity and superior downstream tasks. To tackle this issue, we propose a semantic-preserving image coding and compression method based on the semantics of pixels (SP). Specifically, we first project the semantic importance onto pixels, which is quantified by a gradient-based mechanism. Then, we design an SP-based loss function to train the image coding and compression network. This loss function not only preserves the semantic information to boost the performance of intelligent tasks but also preserves the pixel information to achieve pleasing visual effects. Experimental results confirm improvements in both aspects of performance. Especially for intelligent task performance, the proposed method achieves up to 22.22 % and 78.40 % performance gain ratio compared with the state of art deep learning-based and the traditional method, respectively.

关键词： Training Fading channels Image coding Image communication Semantics Performance gain Visual effects Generative adversarial networks Encoding Image reconstruction

来源：评论

学校读者我要写书评

暂无评论

山地与极地冰川表面生态系统DNA病毒的多样性与功能

引用

Science Bulletin 2023年第20期68卷 2418-2433,M0006页

作者：刘勇勤焦念志钟旭臧琳张锐肖湘施一张志好陶晔白丽萍高变利杨芸兰黄星煜计慕侃刘军志刘鹏飞姚檀栋 Center for Pan-third Pole Environment Lanzhou UniversityLanzhou 730000China State Key Laboratory of Tibetan Plateau Earth System Resources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361005China Department of Earth Oceanand Atmospheric SciencesThe University of British ColumbiaVancouver V6T 1Z4Canada Institute for Advanced Study Shenzhen UniversityShenzhen 518000China State Key Laboratory of Microbial Metabolism School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China Key Laboratory of Development and Application of Rural Renewable Energy Biogas Institute of Ministry of Agriculture and Rural AffairsChengdu 610041China

冰川覆盖了地球表面的10%,是典型的极端环境.病毒在冰川表面生态系统中丰富且活跃,在控制微生物群落中发挥关键作用.然而,我们对冰川表面生态系统病毒及其对下游生态系统的潜在影响了解非常有限.本研究构建了冰川表面生态系统DNA病毒基... 详细信息

冰川覆盖了地球表面的10%,是典型的极端环境.病毒在冰川表面生态系统中丰富且活跃,在控制微生物群落中发挥关键作用.然而,我们对冰川表面生态系统病毒及其对下游生态系统的潜在影响了解非常有限.本研究构建了冰川表面生态系统DNA病毒基因组数据集(SgVG),将已有冰川DNA病毒基因组数量扩展了15倍.数据集包含了来自全球38个山地和极地冰川,涵盖雪、冰、融水和冰尘的10,840个DNA病毒物种.冰川表面DNA病毒特异性高,但对公众健康的潜在风险极低.冰川表面病毒群落结构主要受生境影响,且冰尘病毒最为活跃.裂解性病毒在所有生境中普遍存在,而雪和冰中溶源性病毒的相对比例较高.此外,冰川表面病毒可侵染冰川中83%的门或纲的原核微生物,并且能够编码具有促进宿主代谢和协助宿主适应寒冷环境等功能的多种辅助代谢基因.本研究系统地描述了山地和极地冰川表面生态系统DNA病毒的多样性和功能,为评估冰川DNA病毒的生态功能、安全风险及构建区域生态模型提供了重要科学依据.

关键词：生态系统地球表面生态模型极端环境寒冷环境溶源性原核微生物相对比例

来源：评论

学校读者我要写书评

暂无评论

Multiscale delamination modeling of an anisotropic conductive adhesive interconnect based on micropolar theory and cohesive zone model

Multiscale delamination modeling of an anisotropic conductiv...

引用

International Conference on (ICEPT) Electronic Packaging Technology

作者： Yan Zhang Jing-yu Fan Johan Liu Key Laboratory of Advanced Display and System Applications Ministry of Education and SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden

With the trend towards high performance, portability and low cost for electronic products, the packaging density in microsystem has become higher and the components have tended to be minimal. Flip-chip technology is superior because of its high packaging density and speed signal processing. There is an increasing interest in using electrically conductive adhesives as the interconnection material in flip-chip assembly due to its fine pitch I/Os, fewer number of processing steps, lower process temperature and environmental-friendliness. The interconnect behavior is a key issue in the long-term reliability of the system performance. In the present paper, a multiscale interface model was developed on the basis of micropolar theory, in which a cohesive zone model was also introduced to describe the possible delamination process that might occur when the interconnection was subjected to the thermal cycling loading. The delamination model was implemented using finite element method, and the numerical analysis for the reliability of an anisotropic conductive adhesive interconnect was made as the model application.

关键词： Delamination Anisotropic magnetoresistance Conductive adhesives Electronics packaging Costs Signal processing Conducting materials Assembly Temperature system performance

来源：评论

学校读者我要写书评

暂无评论

Numerical investigation on the effect of filler distribution on effective thermal conductivity of thermal interface material

Numerical investigation on the effect of filler distribution...

引用

International Conference on (ICEPT) Electronic Packaging Technology

作者： Cong Yue Yan Zhang Johan Liu Zhaonian Cheng Jing-yu Fan Key Laboratory of Advanced Display and System Applications Ministry of Education & SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China

Thermal interface materials have been widely adopted in the thermal management for electronics system. Most of the thermal interface materials are made of polymers with thermally conductive particles distributed inside to enhance the thermal conductivity. Thus it is essential to figure out the effective thermal conductivity of this composite material. In the present paper, a parameterized cubic cell model had been developed and implemented by the finite element method. The numerical simulations were carried out to investigate the effect of the filler distributions on the effective thermal conductivity of the thermal interface materials. The volume percentage loadings of the particles ranging from 13% to 74% had been considered, and different particle distribution patterns had also been analyzed. The simulation results were compared with the experimental data as well as other models. A fairly good agreement was obtained for the particle volume percentage loading under consideration, which verified the developed cubic cell model.

关键词： Thermal conductivity Conductivity Materials Mathematical model Electronic packaging thermal management Numerical models Finite element methods

来源：评论

学校读者我要写书评

暂无评论

Computational Fluid Dynamics Simulation for On-chip Cooling with Carbon Nanotube Micro-fin Architectures

Computational Fluid Dynamics Simulation for On-chip Cooling ...

引用

International Symposium on Electronic Materials and Packaging

作者： Xiaolong Zhong Teng Wang Johan Liu Yan Zhang Zhaonian Cheng Key Laboratory of Advanced Display and System Applications & Sino-Swedish Microsystem Integration Technology (SMIT) Center Shanghai University Shanghai China SMIT Center & Department of Microsystem and Nanotechnology Chalmers University of Technology Gothenburg Sweden Department of Applied Mechanics Chalmers University of Technology Gothenburg Sweden

The 2D CFD simulations have been carried out for a series of CNT micro-fin cooling architectures in this paper. The influence of micro-fin structures, fluid speeds and heating powers on cooling effects have been obtained in the case studies, and the numerical results have been compared with our experiment data. The CFD simulations indicate that the fluid speed is the key factor of heat transfer, and the heat generated on chip is removed by liquid mass flowing in the channels of micro-fin architectures. The pressure drop between inlet and outlet of the cooling device is an important cause limiting the fluid speed, and the excessive pressure drop will destroy the carbon nanotube fin arrays. The harmfulness condition of nanotube array is an unavoidable limitation for cooling capability of carbon nanotube micro-fin structures, and consequently it is necessary to study the harmful situations of carbon nanotube. The simulation results in present work also indicate that the cooling capability of 2D carbon nanotube fin array is more efficient than that of 1D carbon nanotube fin array.

关键词： Computational fluid dynamics Computational modeling Cooling Carbon nanotubes Computer architecture Heat transfer Thermal conductivity Heat sinks Electronic packaging thermal management Microchannel

来源：评论

学校读者我要写书评

暂无评论

Room temperature transfer of carbon nanotubes on flexible substrate

Room temperature transfer of carbon nanotubes on flexible su...

引用

International Workshop on Thermal Investigation of ICs and systems (THERMINIC)

作者： Di Jiang Yifeng Fu Yan Zhang Johan Liu Department of Microtechnology and Nanoscience Chalmers University of Technology Göteborg Sweden SHT Smart High-Tech AB Gothenburg Sweden Key Laboratory of Advanced Display and System Applications & SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China Göteborg Sweden

In this paper we report a novel method of transferring thermally grown vertically aligned carbon nanotubes (VA-CNTs) onto flexible substrates at room temperature with a single-step process. The transfer process is carried out by placing the CNT forests upside down on a double sided thermal release adhesive tape and peeling off the silicon substrate. Scanning electron microscope (SEM) is used to observe the transfer results. Also a second transfer using the same method but a thermal tape with higher release temperature is repeated on the as-transferred CNTs forests. The results show that this method is able to provide a novel process for transferring CNT forests at room temperature. This process will help to bring close the low cost fabrication of vertically aligned CNT structures for electronics.

关键词： Carbon nanotubes Substrates Plastics Silicon Physics Arrays

来源：评论

学校读者我要写书评

暂无评论

MDS investigation on the heat transfer properties of CNT micro-channel cooler

MDS investigation on the heat transfer properties of CNT mic...

引用

Electronics system-Integration Technology Conference, ESTC

作者： Yan Zhang Shun Wang Jing-yu Fan Johan Liu Key Laboratory of Advanced Display and System Applications Ministry of Education and SMIT Center School of Mechatronics Engineering and Automation Shanghai University Shanghai China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China SMIT Center & Bionano Systems Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg Sweden

With the continuously increasing packaging density, the corresponding techniques for heat dissipation are vital to high performance components. During the system operation, the heat generated by components must be efficiently transferred outside of the electronic package. To meet the heat removal requirement of the electronic devices with a high power, several liquid cooling schemes have been suggested, among which the micro-channel cooler have gained the most attention. Simultaneously, the carbon nanotube (CNT) has attracted a significant interest in the material properties and exploratory application. Some studies have been recently conducted to evaluate the thermal performance of the CNTs and their applicability for heat removal in integrated circuit (IC) devices. By utilizing the adhesive transfer process to form the CNT bundles as the fins during the micro-channel development, the devices can be immune from the high temperature required by the CNT growth process. In the present paper, the interface heat transfer in the CNT-based micro-channel cooler has been investigated. The thermal resistances introduced by the interface between the CNT and the epoxy due to adhesive transfer and the interface between the CNT and water have been simulated by molecular dynamics simulation (MDS) method. And the thermal resistance at the interface between the CNT and the epoxy is about 1.0×1.5 - 10 -8 Km 2 /W. The obtained MDS results are likely to provide the microscopic understanding of the thermal performance of the CNT micro-channel cooler as well as provide references to the macroscopic evaluation of the thermal efficiency for the micro-channel cooler design and optimization.

关键词： Heat transfer Thermal resistance Carbon nanotubes Conductivity Materials

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：