表面安装技术在我国电视行业中的应用前景

<正> 一、表面安装技术概述随着电子工业的发展,提出了高密度、高可靠性的要求,于是产生了一种小型化或微型化、具有无引线或短引线结构、能够在绝缘布线板上进行表面组装的元器件,这种元器件称为表面安装元器件(SurfaceMount Component简称SMC)。随着SMC的产生,同时也出现了相应的安装技术既表面安装技术SMT(Surface Mount Technigue)。这种技术是在六十年代初期开始应用的,但仅局限于有限的范围。近几年来,随着SMC的兴起和蓬勃发展,使得长期以来一直沿用的传统通孔安装技术(Through Hole Technigue简称THT)发生了重大的变革,表面安装技术标志着电     

Hg2 + 离子传感器的最新研究进展

综述了汞离子传感器的最新研究进展，主要介绍了利用光化学传感器、离子选择电极和生物传感器检测汞离子的状况，重点分析比较了功能材料和传感器特性。在此基础上，介绍了我们的研究情况，通过两个阶段的固相反应合成了汞离子传感器，并且通过激光脉冲沉积(PLD)技术把靶材(汞离子传感器)制备在光寻址电位传感器(LAPS)的表面上，形成薄膜，实现了汞离子传感器的微型化。     

电化学传感器及其在芯片实验室中的应用

芯片实验室是一种微型化的生化分析仪器 ,而电化学传感器具有灵敏度高、易微型化、功耗小、成本低的特点 ,特别是它与目前的微电子机械系统技术兼容 ,因此它在芯片实验室发展过程显示出了诱人的应用前景。介绍了电化学传感器的原理、分类及其在芯片实验室中的应用。     

水下爆炸压力传感器技术研究综述

压力是水下爆炸测量的重要参数,相应的传感器技术决定了整体压力测试水平的高低,因此有必要对水下爆炸压力传感器技术的应用及发展现状进行总体性的把握;首先从传感器敏感元件的选择、国内外在中远场、近场压力测量技术等方面概述了自由场压力传感器技术的发展现状,并指出了现在自由场压力测量中存在的一些问题;其次,论述了结构物表面压力测量技术的研究进展,总结了测试难点及对传感器性能要求,并对目前的测试现状进行了评述,指出了结构物表面压力测量传感器技术的发展方向;最后,对水下爆炸压力传感器技术进行了总结并提出了发展趋势。     

微型化Clark氧传感器

叙述运用微电子平面工艺和微机械加工技术实现的微型化Ｃｌａｒｋ氧传感器及其应用实例－微型葡萄糖传感器。     

RFID与传感器网络集成方法研究

RFID技术与无线传感器网络的融合是当今信息领域亟需解决的热点、难点问题。简单介绍RFID和无线传感器网络,论述两种技术融合的研究意义,提出RFID与传感器网络集成方法的研究方案。     

信息纵横

新型微型微压传感器东北传感技术研究所推出一种微型微压传感器，该种传感器前端采用表面齐平安装，提高了动态性能，其固有频率大于３ｋＨｚ，安装尺寸为Ｍ８×１，测量范围０～２０ｋＰａ。由于对传感器的芯片结构进行了特殊设计，可以用于负压测量，并且正、负压力的对...     

基于微/纳米加工技术的微型电化学免疫传感器研究

生物传感器的研制越来越趋向于微型化、集成化、智能化以及无创伤的方向发展.研制基于微/纳米加工技术的电化学免疫传感器顺应了这一趋势,利用微电子机械系统(MEMS)技术在硅基芯片上制备微型三电极系统和SU-8微型池,并采用自组装单层膜和纳米金修饰微型电极表面用于抗体的固定化,研制出新型的电化学免疫传感器.研究表明,这种微型电化学免疫传感器易于实现批量生产,便于集成,检测过程只需要少量的样品,大大降低有毒试剂的消耗,减少环境污染,同时具有分析成本低,响应时间快,检测下限低和适用于现场快速检测等优点.     

新型传感器连连看

传感器的作用是将一种能量转换成另一种能量形式,而这样的转换越来越多地应用在了民用、工业甚至军用领域。近些年,传感器不仅朝着智能化和微型化发展,还在技术与形式上有了不少创新。本期我们将关注一些新型的传感器,并从技术和市场方面加以分析。     

用于农药残留快速检测的酶生物传感器研究进展

酶生物传感器以快速、操作简单、易于微型化等优势成为农药残留在线监测领域的研究热点。综述了近年来国内外农残速测酶生物传感器中所用酶的种类、酶固定化技术的发展与现状。探讨了影响酶生物传感器工业化进程的瓶颈,并展望了其发展趋势。     

Modulation of the diffusion coefficient of a hapten-modified redox species as a basis for an amplified electrochemical affinity assay

An affinity assay was developed that is based on the modulation of the diffusion coefficient of an electroactive label upon complementary recognition leading to an increase of the molecular weight. Using an electroanalytical technique, which is correlated to the diffusion coefficient of the redox species, e.g., cyclic voltammetry, the decrease of the diffusion coefficient can be monitored as a decrease of the diffusion-limited current. Signal amplification was achieved by redox recycling using a microelectrode that is positioned in close distance to a conducting surface. The amplification rate can be adapted by varying the distance between the microelectrode and the conducting surface. As a model system for molecular recognition, the biotin–streptavidin system has been chosen using a ferrocene-labeled biotin derivative as electroactive species. The generality of the approach was proved by extension of the basic assay to related sandwich assays and by miniaturization using a wall-free droplet cell.     

Geometrically progressive stub loading scheme for miniaturization of transmission line‐based components

This paper presents a novel slow wave structure (SWS) using geometrically progressive loaded shunt stubs for miniaturization of microstrip lines. It is observed that, compared to the conventional periodically stub loaded SWS, the proposed technique renders further miniaturization of around 20%, theoretically. Apart from that, this technique also helps in suppression of higher pass bands inherently present in SWSs. A detailed analysis of this technique has been carried out with corresponding design scheme. For proof of concept, this miniaturization scheme is applied to a rat‐race coupler designed at 2 GHz, where 75% reduction in overall footprint is observed. The simulated and measured results are found to be in good agreement with the proposed theory.     

基于ARM11的微库仑综合分析仪的研制

利用微库仑滴定技术的测量原理设计一款基于ARM和WinCE6.0实时操作系统的嵌入式新型微库仑分析仪。硬件设计包括电解电极采集信号电路、炉温控制电路、进样器电路、积分电路、背压检测电路、串口通信电路及质量流量控制电路;软件设计包括积分起始点和终点的判定、滴定曲线绘制、峰形面积计算、样品含量计算、参数设置以及利用校准法得到样品浓度。实验结果表明,该系统具有精度高、测量速度快、小型化、一体化、智能化等优点,能够测量固体、液体、气体中的硫、氯、氮等元素的含量,对今后同类系统的研发有一定的参考价值。     

基于nRF24LE1的手持式RFID系统设计

本文介绍了一种基于nRF24LE1射频芯片的手持式RFID系统的设计和实现方法。采用2．45GHz有源RFID技术,结合ARM嵌入式系统以及倒F型单极天线技术实现了多模块、小型化、多功能的RFID系统。实测结果表明,所设计的RFID系统的性能能够满足应用需求。     

Miniaturized flowthrough microdispenser with piezoceramic tripod actuation

In this paper, the further development of a silicon flowthrough microdispenser is described. Previously reported designs of the dispenser used bimorph, and later multilayered, piezoelectric actuator elements for the generation of droplets. The introduction of a multilayered actuator significantly reduced the voltage amplitude needed to dispense droplets. Dispenser properties relevant for chemical analysis systems, e.g., reduced sample volume, internal surface area, and dispersion, were improved by miniaturization of the device. A new actuator design, the tripod, is presented to enable further dispenser miniaturization and to facilitate device assembly. Tripod actuators were manufactured using a prototyping process, based on micromilling, for multilayer piezoceramic components. A building technique for miniaturized electrical interconnects, based on microstructured flexible printed circuits, is also suggested in line with the prospect of future miniaturization. The microfluidic properties of the tripod-actuated dispenser were evaluated. Stable droplet generation in the frequency range from 0 to 3 kHz was demonstrated, providing a maximum dispensed flow rate of 7.8 /spl mu/L/min.     

A novel super compact half‐mode substrate‐integrated waveguide filter using modified complementary split‐ring resonator

A novel super compact filter based on half‐mode substrate‐integrated waveguide (HMSIW) technology loaded by the modified complementary split‐ring resonator (MCSRR) is proposed. The working principle of the proposed filter is based on the evanescent‐mode propagation technique. According to this technique, by loading the complementary split‐ring resonator (CSRR) on the metal surface of the substrate‐integrated waveguide (SIW) structure, an additional passband below the SIW cutoff frequency can be obtained. In order to miniaturize the physical size of the conventional CSRR, a new method is introduced. In the proposed MCSRR unit‐cell, the meander slots are carved inside all of the interior space of the ring. Accordingly, the length of the slot is increased which leads to an increase in the inductor and capacitor of the proposed structure without occupying the extra space. Therefore, the electrical size of the proposed MCSRR unit‐cell is reduced. Consequently, the resonance frequency of the proposed MCSRR unit‐cell is decreased compared to the conventional CSRR with the same sizes. Namely, the lower resonance frequencies can be achieved by using this technique without increasing the size of the unit‐cell. In order to confirm the miniaturization technique, two HMSIW filters loaded by the proposed MCSRR unit‐cell are designed, fabricated, and experimental verifications are provided. The results show that a miniaturization about 67% is achieved.     

3DS MAX三维动画在化学动力学MCAI课件中的应用

《物理化学》中化学动力学一章讨论化学反应速率和机理。在此 中，有一些化学反应动态过程的理论处理（如碰撞和过渡状态理论）是很难在黑板上形象地加以描述的。３ＤＳ ＭＡＸ提供了能将这些概念和理论以及反应动态过程在三维空间加以形象描述和模拟的有力工具。本文介绍了用３ＤＳ ＭＡＸ动画技术（放样制作造型、布尔运算、材质设计和动画制作）制作模拟双分子反应过程的位能面ＭＣＡＩ课件的过程。在此课件中，一个由三原子组     

Simulation of the surface profile of the groove bottom enveloped by milling cutters in single screw compressors

In machining of a single screw compressor, the milling technique of screw rotor grooves with cylindrical milling cutters has far higher machining efficiency than turning. But, the screw groove bottom surface produced by the flat end of milling cutters will fail to mesh with the flat tooth tip hermetically, and thus give rise to compressed gas leakage. This paper carries out a mathematic simulation of the screw groove bottom surface profiles. The research brings screw groove bottom profiles machined by different cylindrical milling cutters to light, and provides some references for designing the column envelope meshing pairs in single screw compressors.     

Group signature implies public-key encryption with non-interactive opening

In this paper, we show that public-key encryption with non-interactive opening (PKENO) can be constructed from an arbitrary group signature (GS) scheme which is secure in the dynamic group setting and provides opening soundness. Moreover, the resulting PKENO construction is efficient if the underlying GS scheme is efficient and the message space of the PKENO scheme is restricted to short messages. Hence, our result not only shows that the existence of this type of GS implies the existence of PKENO, but also that designing a practical GS scheme is as difficult as designing a practical PKENO scheme. Our transform is constructed by carefully investigating the relationship between the functionalities of GS and that of PKENO, and developing a novel (but specific) multiple encryption technique. This multiple encryption technique plays an important role for simultaneously achieving both practical efficiency and security.