首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 115 毫秒
1.
采用有限元软件模拟了能量高斯分布的连续激光辐照金属靶材的温度场,分析了激光光斑半径和辐照时间对靶材温升的影响,对靶材温升速率随时间的变化情况作了探讨.结果表明:靶材升温区域主要集中在激光辐照区,温升区域随激光光斑半径和辐照时间的增大而扩大,靶材温升速率随辐照时间而变化,辐照前期,温升速度较快,辐照后期,温升速度较慢.  相似文献   

2.
杜立峰  肖谦裔  张蓉竹 《红外与激光工程》2016,45(7):721001-0721001(5)
搭建了涡旋光在多层介质膜中的传输模型,分析了涡旋光垂直入射下膜系内的温升分布。结果表明,膜系内的温升分布与涡旋光入射面密切相关。当涡旋光在初始面入射时,膜系的温升区域集中在入射中心。当涡旋光在空间中传输一定距离后再入射膜系时,膜系温升区域向入射中心的两侧发散,且最大温升大于初始面入射时的温升。当传输距离足够远时,膜系最大温升随传输距离的增加而减小。另外,在一定传输距离内,膜系最大温升随拓扑荷数的增大而增加。传输距离足够远时,最大温升随拓扑荷数的增大而减小。  相似文献   

3.
本文在理论和试验两个方面探讨了离子注入中的热效应和温升现象。注入样品的温升对离子注入层的性能有直接影响。分析了理论计算注入样品温升的一些情况。给出了实际测量注入样品温升的几种试验方法。阐明了控制注入样品温升的若干可能途径。  相似文献   

4.
姜克  江皇君 《电子质量》2011,(12):51-52,65
简述在故障条件下按摩电器绕组温升过高的普遍现象。对按摩电器中的变压器绕组温升提出了多种控制方法以满足安全要求;阐述了利用电阻法测试电动机转子绕组温升存在的关键问题,分析了影响测量不确定度的因素,对正确测量电动机转子绕组温升提出了一些观点。  相似文献   

5.
基于二次吸收发热模型,考虑了激光介质的端面效应,对有限尺寸的管状YAG激光器介质温升进行了计算分析.结果表明,介质横截面上的温升呈环状分布,激光管壁中心部分的温升最大,内壁和外壁的温升较小,且外壁温升低于内壁温升.聚光腔反射率越大、厚度越厚、泵浦功率越大、吸收系数越大,都会使得介质内的温差升高,从而使得热效应不断加剧.  相似文献   

6.
通过分析电缆绝缘参量的温度效应和老化特征,明确运行中矿用高压电缆的介质损耗不可忽略,并据此建立了老化对在役矿用XLPE电缆温升影响的评估方法.根据单芯电缆温升计算式,给出了兼顾老化因素的三芯电缆温升解析式,进行稳态温升预测.基于导体损耗的温度正相关性,利用ANSYS有限元仿真软件,建立热电耦合迭代模型来确认理论模型,并对电缆温升进行仿真计算.算例对比分析了老化电缆水树附近和老化电缆整体的温升,为实际运行中电缆的状态监测提供参考依据.  相似文献   

7.
大电流电器设备在温升试验中需要使用截面积比较大的铜排,而大截面铜排的导热能力强,使得铜排另端的电源或电连接端子形成的热源对试验设备温升有较大干扰,可能导致试验误差.建立一维有限差分模型分析了大电流温升试验中铜排长度对试品温升造成的误差,给出了为减小误差而必须采用的铜排最小长度.其结论对大电流配电板设计中的温升问题有一定参考作用.  相似文献   

8.
随着科学技术的不断发展,电源适配器的种类也越来越多,而电源适配器产品销售必需经过国家的CCC认证,温升测试是其中必不可少的一项安全检测环节。该文通过电源适配器在不同测试条件和测试环境下的温升试验,分析温升试验的差异之处,正确认识温升测试的方法及影响因素,以期为业界相关检验检测人员提供技术上的帮助。  相似文献   

9.
随着信息技术的不断发展,开关电源是各类电子信息设备不可或缺的一部分,变压器又是开关电源中的一个重要元器件,其性能的优劣直接关系到开关电源是否可以安全可靠的工作.利用热电偶温升测试法对开关电源中变压器进行正常温升以及故障状态下的温升测试.该文从试验条件,试验方法以及试验结果等方面对变压器的温升进行判定.  相似文献   

10.
阐述电气设备温升试验和热仿真分析的过程。温升试验记录了设备在不同工作条件下的温度变化,得出了设备的热特性。利用热仿真分析技术,预测设备在不同工作条件下的温升状况。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

16.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

17.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

18.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.  相似文献   

19.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

20.
Call for Papers     
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号