微悬臂梁的热机械性能分析及选材

由微悬臂梁结构组成的红外焦平面阵列(FPA)是基于微机电系统结构的非制冷型红外成像系统的核心技术,通过对双金属悬臂梁应力和应变的分析,阐述了影响微悬臂梁热机械性能的主要因素,为正确选择微悬臂梁结构的材质提供理论依据.     

基于牺牲层释放的微悬臂梁器件制作中的粘附现象

以微悬臂梁的制作工艺为例,针对双材料悬臂梁加工中因为粘附现象造成废品率高的问题,分析了微悬臂梁加工中粘附影响因素,指出表面作用力和残余应力是造成粘附的主要原因,并提出相应控制措施。     

ANSYS在FPA结构微悬臂梁温度场分析中的应用

在FPA中双材料悬臂粱进行合理简化的基础上,建立了FPA中双材料悬臂梁的三维有限元模型。运用ANSYS8．0的热分析功能对成像过程中FPA中双材料悬臂梁的工作环境进行了定量热分析,给出优化设计红外成像元件的思路及依据。     

压电能量收集器的有限元仿真与分析

压电能量收集是微能量领域的研究热点。为了优化压电能量收集器的设计并提高其输出电压,对压电单晶悬臂梁进行了有限元仿真与分析,包括对压电单晶悬臂梁的最大应力,产生的最大电压,以及压电晶片的长度、基板的材质和压电晶片的粘结位置对输出电压的影响都作了详细的研究。仿真结果表明,有限元方法能为压电能量收集器件的优化设计提供重要的理论指导。     

基于ABAQUS下悬臂梁的静力学分析及拓扑优化

悬臂梁是在材料力学中为了便于计算分析而得到的一个简化模型,是研究拓扑优化的一个重要案例。本文主要针对悬臂梁模型进行静力分析和拓扑优化,运用ABAQUS软件对悬臂梁模型进行三维建模、静态仿真及拓扑仿真,得到拓扑优化后的悬臂梁结构。结果表明：通过静力分析得到悬臂梁上各部分的附加内力承受大小和悬臂梁位移方向,分析结果符合预期的结果,拓扑优化后的悬臂梁移除了没有承受附加内力的结构,优化后的模型达到了预期的结果。     

两种双强度悬臂梁压力温度双参量光纤传感结构分析

光纤布拉格光栅(FBG)传感器通常采用普通悬臂梁进行增敏传感,存在温度交叉敏感问题。针对等厚等腰双三角形悬臂梁结构和双厚度等腰三角形悬臂梁结构构成的两种双参量测量设计,采用Ansys和Matlab进行分析,发现等厚等腰双三角形悬臂梁结构在压力影响下不能在其表面产生双强度阶跃应变;双厚度等腰三角形悬臂梁结构在压力作用下其结构表面能产生双强度阶跃应变,温度对结构产生单强度应变影响。根据该特性,建立了解调模型,验证了双厚度等腰三角形悬臂梁结构传感器压力温度双参量检测的可行性。     

基于压电悬臂梁的振动能量获取装置的建模及数值仿真

振动能是自然环境中广泛存在的一种能量,振动式发电机可将其提取并转换为可直接利用的电能。设计了一种用于收集环境中低频振动能的三质量块压电悬臂梁装置,利用压电薄膜的正压电效应将机械能转化成电能。建立悬臂梁的数学模型,用ANSYS软件建立悬臂梁的仿真模型,然后对其进行模态分析,耦合分析,谐响应分析并绘制出压电振子的频率-电压曲线图。研究结果表明该悬臂梁产生的电压可以满足无线传感器节点的使用要求,且优于单质量块悬臂梁。     

磁性聚苯乙烯微球的制备与表征实验设计

为制备表面带亲水性功能基团的磁性聚苯乙烯微球,用无皂乳液聚合方法,以过硫酸钾为引发剂,丙烯酸为稳定剂,制备出单分散的聚苯乙烯微球,在聚合物乳液中,用硝酸钾和氨水氧化硫酸亚铁制得表面修饰四氧化三铁的聚苯乙烯微球,制成磁性功能材料.用红外光谱(IR)、热重量法(TGA)、X射线衍射谱(XRD)和透射电镜(TEM)对合成样品进行了分析.结果表明,实验所得的样品为高品质的、表面单一分散的磁性聚苯乙烯微球,IR光谱在3030～2800,1600,1491.30,1449.42,735,698 cm-1处出现了聚苯乙烯的特征红外吸收,630 cm-1处为聚苯乙烯微球表面的Fe3O4的红外特征吸收;TGA曲线较好地解释产品的热失重现象;XRD谱出现了Fe3O4的特征衍射峰;TEM观察到大小均一、高分散的微球表面已附着Fe3O4磁性微粒.     

微型同位素辐射能收集器二维悬臂梁机电建模

基于欧拉-伯努利梁理论,设计了一种新型的微型同位素辐射能收集器二维机电模型。该模型解决了一维机电模型无法涵盖的诸多问题。算例分析表明:本模型能较准确地描述实验过程和预测实验结果。通过对结果进行分析,得出了影响微悬臂梁的位移、梁的往返周期和梁中存储能量的一系列因素。     

集中荷载作用下悬臂梁的侧向稳定性分析

针对在自由端作用集中荷载的悬臂梁,通过一定的合理简化,建立了悬臂梁的平衡微分方程,并采用近似解法,利用改进的欧拉公式,推导出了悬臂梁失稳临界荷载的计算公式,同时利用ANSYS程序对算例进行了分析,所得结果与理论计算值吻合较好。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.