A Comprehensive Review on Heat Transfer Design Parameters in MEMS through Experimentations and Numerical Modeling

Micro electro mechanical systems are studied in this paper along to comparing the design, fabrication, and operation of such devices especially in the electronic industry. The advancements of such systems are important as scale reduction is becoming more economical and also in heat dissipation efficiencies. Furthermore, the fabrication techniques are becoming more of a challenge in today’s industrial market. In this paper we will introduce a comparative study of experimental research in the micro scale heat exchanger with varieties of industrial application primarily cooling integrated circuits. Significant effect in the process of cooling electronic devices has showed experimentally that scale variations impact into this improvement. Numerical studies have been a leading technique in the development of thermal systems especially at the micro or small scales which helps the industry to cut cost and provide innovative products at high efficiencies. There are so many approaches to numerical analysis and research, where the availability of ready to use software and data acquisition modules is variant. Material selection is also a variable in the efficiency and operations of these micro channel thermal system and heat exchangers.

Stretching directions in cislunar space:Applications for departures and transfer design

Stable or nearly stable orbits do not generally possess well-distinguished manifold structures that assist in designing trajectories for departing from or arriving onto a periodic orbit.For some potential missions,the orbits of interest are selected as nearly stable to reduce the possibility of rapid departure.However,the linearly stable nature of these orbits is also a drawback for their timely insertion into or departure from the orbit.Stable or nearly stable near rectilinear halo orbits(NRHOs),distant retrograde orbits(DROs),and lunar orbits offer potential long-horizon trajectories for exploration missions and demand eficient operations.The current investigation focuses on leveraging stretching directions as a tool for departure and trajectory design applications.The magnitude of the state variations along the maximum stretching direction is expected to grow rapidly and,therefore,offers information for efficient departure from the orbit.Similarly,maximum stretching in reverse time enables arrival with a minimal maneuver magnitude.

AAK Theorem and a Design of Multidimensional BIBO Stable Filters

Rational approximation theory occupies a significant place in signal processing and systems theory. This research paper proposes an optimal design of BIBO stable multidimensional Infinite Impulse Response filters with a realizable (rational) transfer function thanks to the Adamjan, Arov and Krein (AAK) theorem. It is well known that the one dimensional AAK results give the best approximation of a polynomial as a rational function in the Hankel semi norm. We suppose that the Hankel matrix associated to the transfer function has a finite rank.

Analysis of Heat Transfer Performance of Oscillating Heat Pipes Based on a Central Composite Design

Oscillating heat pipes (OHPs) are very promising cooling devices. Their heat transfer performance is af- fected by many factors, and the form of the relationship between the performance and the factors is complex and non-linear. In this paper, the effects of charging ratio, inclination angle, and heat input and their interaction effects on heat transfer performance of a looped copper-water OHP are analyzed. First, suppose that the relationship between the response and the variables approximates a second-order model. And use the central composite design to arrange the ex- periment. Then, the method of least squares is used to estimate the parameters in the second-order model. Finally, multi- variate variance analysis is used to analyze the model. The results show that the assumption is right, that is to say, the re- lationship is well modeled by a second-order function. Among the three main effect variables, the effect of inclination angle is the most significant, but their interaction effects are not significant. In the range of the considered factors, both the optimum charging ratio and the optimum inclination angle increase as the heating water flow rate increases.

Research on Flexible Transfer Line Schematic Design Using Hierarchical Process Planning

Flexible transfer line(FTL)is now widely used in ma ny manufacturing domains to realize efficiently,high quantity and economic prod uction.These manufacturing domains include automobile,tractor,internal-combu stion engine,and so on.In today’s competitive business environment,it is vit ally important for machine tool manufacturers to design flexible transfer line m ore effectively and efficiently according to a wider variety of customer demand s.This paper proposes an approach to a bidding-based flexible transfer line sc hematic design system.By analyzing manual FTL design process,the architecture o f flexible transfer line schematic design system(FTLSDS)is established.The syst em consists:of four processes:part feature modeling,process planning,FTL fac i lity layout and FTL evaluation. For FTL schematic design.a five-level proces s planning strategy named hierarchical process planning method is proposed.This method includes selection of manufacturing feature machining operation;part se t-up planning,feature sequencing,operation sequencing and process plan genera ting.The major decision relies on setup planning.According to the proceeding o f the hierarchical process planning,the structure of reasoning is proposed base d on blackboard.Under this paradigm,a cooperative effort between a hybrid coll ection of knowledge sources is possible.Total reasoning task can be divided int o some subtasks,and recursive-reasoning system is formed.It is convenient for process planning with step-by-step solution.Meanwhile,the blackboard is use d as the global data exchange area during all reasoning process.By using modula r technology,special purpose machine tools can be designed more efficiently and rapidly.The framework of machine modular design system to support machine requ irement design for FTL is established.By synthesizing the FTL evaluation criter ia.five evaluation criteria of flexible transfer 1ine schematic design are take n into account.An exampie is supplied to demonstrate and verify the validity an d feasibility of flexible transfer line schematic design approach.

Two t-out-of-n Oblivious Transfer Schemes with Designated Receiver

Oblivious transfer （OT） protocol is a fundamental cryptographical tool and widely used as a building block of secure computation. In this work, we propose two efficient t-out-of-n oblivious transfer schemes with the designated receiver. A common advantage of the two schemes is efficient. The total computation cost of the sender and the receiver is n ＋ 2t ＋ 1 modular exponentiations in first scheme that is three-round, and the total one of the sender and receiver is n ＋ 3t modular exponentiations in second scheme that is two-round. Another advantage of both schemes is designable.

Design of control sequence of pulses for the population transfer of high dimensional spin 1/2 quantum systems

On the basis of the relationship between the Hamiltonian of spin 1/2 quantum system under control and the energy level structure and transitions, a radio frequency pulse sequence is designed using intuitive and half counter-intuitive sequences of pulse to transfer the population of the 3-qubit system coherently. The effectiveness of the designed control sequence is verified through the system simulation experiment of the evolution of state. In principle, the design method of the control pulse sequence proposed can be generalized to use in the quantum systems of higher dimension.

Research on Rapid Response Schematic Design for Flexible Transfer Line CAPP-Based

To meet the market requirements for Flexible Transf er Line (FTL), which consists of modular NC machining tools of high quality and co st saving, the methodologies and technologies of client-oriented FTL rapid resp onse schematic design CAPP-based, one of the key techniques, are presented in t his paper. In order to achieve this purpose, an integrated system for integrated design of CAD/CAPP/FTL with box-type parts is realized. In this paper, firstly the theory of the conceptual design of FTL based on CAPP is established and the software architecture is developed. The global-domain pr oduct model is put forward to meet with data representation. After the manufactu ring feature is analyzed and decomposed for machining operations, the feature-b ased part unified data model object-oriented is built. Secondly the knowledge- based CAPP system data model is established. The process planning unit model is formed by work element (WE), which is tool-cell based function abstraction meth od, and has unified layers with respect to designing and manufacturing. With WEs through dynamic response and simultaneous structure in process planning, the pr inciple solution for CAPP function system can be implemented. Lastly the mapping from process domain to module design domain is built. The unidirectional select ion process based on fuzzy matching technology is easily dealt with computer. Th e algorithm of decision with fuzzy synthetic evaluation method and technology is applied to estimate the feasibility of the results in local working procedure o f modular NC machine tools and make decision of designs in overall FTL, which co nsists of many different factors. The example shows that the rapid response desi gn in bidding-based FTL scheme design is realized.

Effect of seismic design details on hysteresis performance of SRC-RC transfer columns

Four types of seismic design details were tested using 11 transfer column specimens and one comparison specimen of RC under low cyclic reversed loading. Test results show that diagonal cracks control the failure pattern and damage occurs mainly in the RC section with weak shear capacity in the transfer columns. There is a large difference in the bearing capacity and ductility of the transfer columns according to the test results, which indicates that the strengthening effect of diverse structural measures is quite different. The section ratio of I-section-encased steel and the axial compression ratio also have a great influence on the bearing capacity and ductility. Although the bearing capacity of transfer columns with additional longitudinal bars and additional X bars is relatively large, they have poor deformation capacity. Setting more stirrups along the columns is the best structural measure to enhance the seismic performance. The studs on the I-sectionencased steel by welding can help to complete the stress transfer between the steel and concrete, and avoid performance degradation of the two materials due to bonding failure.

准领属构式的实现机制

以往研究多从生成的角度讨论准定语问题,本文认为,准定语并不需要经过移位或糅合等句法操作程序生成,而是直接在领属结构形式“N_(1)的N_(2)”的基础上实现。其实现条件和机制为:当N_(2)为实体名词时结构存在实现准领属关系的可能,但需要“压制”机制同时起作用,即抑制N_(2)的实体意义而凸显其属性意义,其途径是转指;而构式压制的方式是通过一系列去及物化操作使N_(2)表现为无指,从而准领属构式得以形成。

基于场协同理论的热空气吹掠型太阳能蒸馏器对流传热性能优化分析

以热空气吹掠型太阳能蒸馏器为研究对象,利用数值模拟结果和均匀设计法分析蒸馏器内流动与传热场协同角的变化规律和影响因素。结果表明,影响场协同角的主要因素是热空气进口速度,热空气进口温度和水温的影响不显著。在蒸馏水温30~70℃、进口空气温度40~90℃,进口空气速度为8 m/s时平均传热场协同角最小,为73.14°,传热系数最大,可达到同等条件下自然对流传热系数的4倍。

基于角域重采样和领域对抗网络的滚动轴承故障迁移诊断方法及实验分析

该文提出一种基于角域重采样和领域对抗神经网络的电机滚动轴承跨工况故障迁移诊断方法。首先对不同工况下的时域振动信号进行角域重采样,用以降低不同转速下振动信号的时频差异;然后利用领域对抗学习策略提取出源域与目标域数据中的领域不变特征,进一步减小不同工况间的数据分布差异。该文还搭建了电机滚动轴承故障诊断实验平台,针对6种跨工况迁移诊断任务开展了验证实验。实验结果表明,所提方法的故障平均迁移识别率高达95.08%。该故障诊断方法实验研究涉及信号处理、深度学习等领域知识,有助于学生掌握基本原理,锻炼理论联系实际的能力。

城市轨道交通大型换乘车站应急防灾设计

[目的]鉴于大型城市轨道交通(以下简称“城轨”)换乘车站数量不断增加,以及该类车站具有埋深较大、人员密集、逃生救援场地受限的特征,应急防灾难度和压力十分突出,因此需要对此类型车站的应急防灾进行设计。[方法]以武汉光谷广场综合体工程作为实际案例,从火灾防护、大客流防护、洪涝防护、恐袭防护及突发疫情防护等5个重点方面,分析大型城市轨道交通车站所面临的灾害特征,结合方案设计、模拟仿真、计算分析等方式,对不同类型的灾害提出解决方案。[结果及结论]采用开放式的建筑布局和贯通的人行交通层,结合自然排烟与下沉广场设置准安全区,是困难条件下大型地下空间的有效消防措施;结合车站特点分析客流高峰情况,对不同时段、不同类型的使用人群进行分类,并设置相对独立、交叉少的流线,以有效地进行大客流防护;除常规的洪涝防护措施外,提高与周边地下空间的硬隔离措施,如增加防淹门是作为洪涝防护的必要手段;提高站内的通透性,快速疏解乘客,避免堵塞滞留可有效防护恐怖袭击;对于突发疫情防护,应严格按照我国相关管理规定,落实日常防控管理,适时采取一般疫情或较大疫情响应措施。

铜凿剪纸风格化方法研究

铜凿剪纸是一种在铜箔上凿点并使用矿物质颜料上色的传统艺术形式,其成品光彩夺目。铜凿剪纸工艺复杂、制作时间长,对手工艺人的技术水平有很高的要求。为此,提出了一种铜凿剪纸风格化的方法,并设计、实现了一种计算机辅助铜凿剪纸设计工具,通过生成图像线稿、凿点图以及铜凿剪纸效果图,帮助手工艺人快速完成铜凿剪纸的创作和制作。将输入图像进行区域分割以提取图像的线条,生成图像线稿;定义了一种颜色损失函数,结合贪心算法和梯度下降法求解函数最小值得到最佳颜色映射方案;基于VGG-19网络对图像线条进行风格迁移,生成凿点图;将线条风格迁移图像与颜色迁移图像进行融合,生成铜凿剪纸效果图;基于PyQt5框架开发铜凿剪纸设计工具,设计了交互平台。实验结果表明,该方法能够实现图像的铜凿剪纸风格化,且效果接近真实的铜凿剪纸,支持手工艺人快速生成工艺流程中需要的图像线稿、凿点图以及效果图等相关材料,提高铜凿剪纸的制作效率,具有较高的应用价值。

基于交互式设计超材料建模与分析的MCR-WPT效率提升研究

超材料具有特殊的磁场调控能力,被广泛关注并应用于磁耦合谐振无线电能传输(MCR-WPT)领域,但寻求针对特定领域目标需求的超材料设计具有挑战性.目前,超材料的一般设计方法为S参数反演法和等效电路法,设计流程通常需要多次建模仿真得到目标参数,该过程较为繁琐耗时.对此,深入分析上述两种设计方法的特性并将二者结合,采用HFSS与MATLAB软件交互设计和优化用于MCR-WPT特性提升的超材料,有效简化了超材料的设计过程.以无线电能传输效率优化为目标设计方形和Koch两种超材料单元,分析对比两种单元的电磁特性.搭建工作频率为6.78 MHz的MCR-WPT系统实验平台,探究两种超材料对传输效率的影响.实验结果表明,方形超材料和Koch超材料分别实现了28.4%和24.6%的最大传输效率提升,证明了交互设计可以更简便地设计超材料并且用于无线电能传输系统传输效率的提升.

海水对UUV WPT系统的影响及耦合机构的补偿研究

针对水下无人航行器(UUV)无线电能传输(WPT)系统的效率和稳定性问题,建立了水下WPT等效电路,并对其工作原理进行了数学推导和分析。以此为基础研究了海水环境对WPT电路性能的影响机理,推导出了WPT系统在海水中的传输功率及效率模型。由于在海浪和海流等水下外界干扰下电能传输机构的收/发端均会产生偏移,从而影响系统电能传输的稳定性和效率。为减小影响,分析了4种典型拓扑补偿电路结构,并给出了最优补偿电路选取原则。最后,在MATLAB平台进行验证,结果验证了数学推导的正确性以及补偿电路设计的有效性。研究结果可为类似水下无线供电系统的设计提供借鉴。

电场耦合式无线电能传输技术在航天领域应用前景展望

将无线电能传输技术引入航天器的旋转供电中是推动航天器进一步发展的重要手段。而现有应用最广的磁耦合式无线电能传输技术(inductive power transfer,IPT)因成本高、重量大、存在涡流损耗等缺陷而难以在航天领域中得到大规模应用。而电场耦合式无线电能传输技术(capacitive power transfer,CPT)以其成本低、重量轻等优点,近年来受到广泛关注,在航天领域具有巨大潜力。从传统IPT技术在航天领域应用的缺陷入手,分析将CPT技术引入航天领域无线供电场景的重要性。进而介绍了CPT技术的发展历程与基本原理,并对CPT技术在轻量化、大功率、旋转型三个领域的研究现状进行综述来论证其在航天领域应用的潜力。最后总结了CPT技术在航天领域应用存在的问题并分析了解决这些问题可行的技术手段。

基于电场耦合的电能信号并行传输系统串扰抑制方法

针对较大功率电场耦合无线电能传输系统信号双向高速传输的需求,该文提出一种基于部分能量通道的电能与信号并行传输系统的串扰抑制方法。通过对所提出的系统拓扑进行分析,给出了电能传输增益表达式与电能串扰增益表达式,并分析了阻波电路参数变化对电能串扰增益的影响;基于交流阻抗法及香农定理分别给出了信号传输增益及信道容量表达式,分析了信号支路参数对信道容量的影响;在综合考虑信号传输增益、信道容量及阻波电路参数敏感性的情况下,给出系统信号支路参数的设计方法。该方法能保证系统在较大功率下降低电能串扰,保障信号稳定传输,实现信号的双向高速传输。通过仿真与实验验证了所提出的拓扑和参数设计方法的有效性。搭建的实验装置实现了传输530.4 W的电能,23.28 Mbit/s信号正向传输速度和24.2428 Mbit/s信号反向传输速度。

基于培训迁移理论的环境设计教师TPACK能力提升研究——以“历史文化名村名镇保护和活化创意师资培训项目”为例

培训迁移理论关于影响因素的分析和评价方法的研究,为师资培训提供了高效的分析框架。“钱塘江流域历史文化名村名镇保护和活化创意师资培训项目”在该理论指导下,研究环境设计教师TPACK能力提升的途径,包括:在培训计划阶段沟通谋划确定培训设计,引导教师树立正确的培训动机;在培训实施阶段优化培训内容设计,塑造良好的培训环境,促进教师TPACK能力感知;在应用阶段推动教学实践应用和培训评估,积极营造持续学习氛围,实现TPACK能力的应用和融合。本研究期待为环境设计师资培训提供理论与实践依据。

基于钳位电路的LCC-S补偿型感应电能传输系统抗偏移方法

在感应电能传输(IPT)系统中,线圈错位难以避免,造成的耦合变化会导致系统的传输功率不稳定。为了保证IPT系统的供电灵活性,系统需具有容忍线圈宽范围偏移的能力。为此,该文借鉴模态切换的思想,提出一种基于钳位电路的LCC-S补偿型IPT系统,用于增强系统抗偏移性。与传统多模态切换的IPT系统相比,该系统中的钳位电路可根据耦合变化自适应地导通或关断,以调节工作模态,从而实现近乎恒定的功率输出,该方法无需耦合识别、输出检测及反馈通信等辅助手段。该文对系统不同工作模态的功率传输特性进行了推导和分析,并结合系统设计相关约束条件,提供一套参数化设计方法。最后设计并搭建一套500 W的实验装置,验证了理论分析的正确性与可行性。实验结果表明,该方法在耦合度为0.205~0.42的情况下,输出功率稳定在470~505 W之间,效率为83.29%~90.21%。