A Solenoid-Type Inductor Fabricated by MEMS Technique

A solenoid-type inductor for high frequency application is realized using a micro-electro-mechanical systems (MEMS) technique.In order to achieve a high inductance value and Q factor,UV-LIGA,dry etching technique,fine polishing and electroplating technique are adopted.The dimensions of the inductor are 1500μm×900μm×70μm,having 41 turns with a coil width of 20μm separated by 20μm spaces and a high aspect ratio of 3.5∶1.The maximum measured inductance of the inductor is 6.17nH with a Q factor of about 6.     

3.3V逻辑系统的廉价隔离5V电源

3.3V逻辑系统有时需要一个外设功能的隔离电源。这可使用某些 dc-dc变换器。假若在电路中有备用的倒相器,则只用4个倒相器和少量分立元器件就可以产生一个廉价的解决方案。 本文给出的设计采用4个倒相器产生一个带互补输出的方波RC振荡器(见图)。输出倒相器驱动开关晶体管(ZTX451),而晶体管又驱动一个市售的低功耗变压器。变压器(76253/35)可用于带MAX253IC的3V～5V的电源系统。在本文所示的电路中,分立的倒相器和晶体管模仿IC的基本功能并且产生200kHz的振荡器频率。     

基于性能的输电塔地震易损性分析

本文以某高压输电塔为研究对象,同时考虑了结构本身的随机性和地震作用的随机性,采用了非线性屈曲分析及动力响应分析对结构的抗震性能、地震反应进行了分析。在基于性能的分析框架下,通过蒙特卡罗数值模拟获得了输电塔的抗震能力曲线,并分析了其统计特性,计算得到结构的地震易损性曲线,为输电塔的抗震防灾规划提供风险评估的数据基础。     

中国建材企业“走出去”北京宣言

正建筑材料是显示人类文明文化的主要标志之一。中国建筑材料的历史悠久,为人类文明发展做出了巨大贡献。如今,中国建材行业正在践行"创新提升、超越引领"的发展战略,已经开始由产品"走出去"为主转向以资本"走出去"为主的国际化经营转型,以最新的建材产品和准备以最新的技术装备融入广泛的国际市场。参加"中国建材企业‘走出去’座谈会"的全体代表,就中国建材产品、技术、装备加快"走出去"步伐,为奠定中国建材工业创新提升、超越引领世界建材工业迈出新的征程形成共识。为此,     

Processing Research on Shaping Porous 316L Stainless Steel via SLS

The principles of selective laser sintering (SLS) were applied in this experiment .The influence of laser power, scan distance, scan speed and other processing parameters of fiber laser on the pore properties, elastic modulus, and micro morphology, etc were investigated in this paper. Tests were conducted on 316L stainless steel powder. The results showed that porous metal material that meets the requirements of porous bionic human bone material (porosity of 33.4%-37.8%, average pore radius of 94.2-178 μm, ...     

设计适合工业、电信和医疗应用的鲁棒隔离式I~2C/PMBus数据接口

正工业和仪器仪表(II)、电信以及医疗应用的一个关键要求便是用于传输数据的可靠接口。I2C总线是一种双线制双向总线,用于集成电路之间的低速、短距离通信。I2C是由飞利浦公司于20世纪80年代早期为单个电路板上的IC开发,其应用依然在不断增长。电源管理总线(PMBus)是一种速度相对较慢的双线式通信协议,该协议基于I2C,可针对电源进行数字管理。PMBus协议定义了一种开放标准数字电源管理协议,能为与电源转换器或其他连接器件通信提供便利。     

大连华信(国际)软件园,大连,中国

<正>大连市位于辽东半岛的南端,海浪、山丘的光影,呈现出滨海城市的自然景色,沿城际干道西行,海风瑟瑟,感受到远离市区的郊外氛围。软件园用地位于城市干道与山腰之间升起的一块狭窄坡地上,距市中心约30km的樱桃沟。建筑布局只好依等高线两侧延伸,主体建筑所在的台地高出城市道路20m,绿色的山坡看起来很美,充满了山地建筑的诱惑。依山就势布置建筑组合,沿S形道路盘山而上几乎是唯一的选择。     

Memristive Artificial Synapses for Neuromorphic Computing

Neuromorphic computing simulates the operation of biological brain function for information processing and can potentially solve the bottleneck of the von Neumann architecture.This computing is realized based on memristive hardware neural networks in which synaptic devices that mimic biological synapses of the brain are the primary units.Mimicking synaptic functions with these devices is critical in neuromorphic systems.In the last decade,electrical and optical signals have been incorporated into the synaptic devices and promoted the simulation of various synaptic functions.In this review,these devices are discussed by categorizing them into electrically stimulated,optically stimulated,and photoelectric synergetic synaptic devices based on stimulation of electrical and optical signals.The working mechanisms of the devices are analyzed in detail.This is followed by a discussion of the progress in mimicking synaptic functions.In addition,existing application scenarios of various synaptic devices are outlined.Furthermore,the performances and future development of the synaptic devices that could be significant for building efficient neuromorphic systems are prospected.     

低视力病因组成及预防

本文通过对173名低视力患者进行病史问诊、屈光检查和裂隙灯检查,给予低视力助视器验配,并对低视力患者病因进行统计,对低视力患者的病因有了更多认识.对于低视力应做到未雨绸缪,根据低视力形成的原因,采取预防为主、提前干预的有效方案进行防控.     

Influence of Surface-Active Elements on Fluid Flow of MIG Weldpool

A mathematical model describing the behavior of metal inert gas (MIG) welding isformulated in the paper. By means of numerical simulation, the influence of surface-active elements on fluid flow of MIG weldpool is studied. The calculation resultsshow that by adding surface-active elements, the fluid flow behavior is drasticallychanged and the flow fluid flows from lower to upper in vertical direction at the rearof weldpool (w>0). The physical phenomenon is explained from the viewpoint of fluidflow behavior of weldpool that the properties of weld metal is greatly improved andthe content of diffused hydrogen is reduced, thus providing a basis for developing newwelding materials.