CKZB型32次定时钟

<正> CKZB型32次定时钟主要用于学校、机关等单位的打铃控制,也可用于路灯、广告牌等电器的定时启停。它具有以下主要功能:(1)打铃控制。一天内可设定最多32次响铃或16次开和16次关的动作。(2)有普通响铃、预备铃和开关通断三种输出方式。普通响铃方式是在每次定时时间的头20s内响铃。预备铃方式是在每次定时时间先响铃5s,停30s后再响铃20s。开关通断方式是在单次定时时间接通电源,在双次定时时间切断电源。(3)可选择每日循环定时或周一～周五循环定时,周六、周日不定时(双休日不响铃)。(4)内置3.6V/60mAH可充电电池,市电停电时定时钟可维持工作数百小时。     

超100 Gbit/s高速正交频分复用传输技术

光纤通信网络已进入速率超100 Gbit/s时代,并向400 Gbit/s/1 Tbit/s迅速发展。目前在400 Gbit/s/1 Tbit/s 速率以上的多数试验中,高速 O-OFDM(光正交频分复用)可行的传输方案有 CO-OFDM(相干探测光 OFDM)、AO-OFDM(全光OFDM)和混合型电光 OFDM三种系统。文章对比分析了三种高速 O-OFDM系统发射端和接收端结构,综述了三种系统在高速光纤传输中的性能优缺点以及下一步研究的重点。     

40Gb/s单信道光纤传输系统性能仿真分析

利用Optisystem仿真软件,对40Gb/s单信道传输系统中归零(RZ)调制和非归零(NRZ)调制两种格式进行仿真,并且对基于RZ调制格式下的单信道40Gb/s的色散补偿进行了仿真,比较了前置补偿、后置补偿和对称补偿的传输性能.仿真结果表明:在长距离传输时RZ调制格式优于NRZ调制格式,三种补偿方式中对称补偿效果最优.     

集成电路与IP芯核

1MS/s的16位逐次逼近A/D转换器 Analog Devices最近推出的AD7677是16位A/D转换器,采样速度为1MS/s,INL指标为1 LSB。差分输入、不存在流水线延迟。有三种采样速度不同的工作方式:采样速度为1 MS/s,用于异步采样;采样速率为800 kS/s的“正常”方式;最高采样速率为666 kS/s的“脉冲”方式,这时功耗随吞吐量而改变,适合于电池供电的系统。AD7677的S/(D+N)指标典型值     

语音的波形编码及其实时执行

数字语音编码主要解决如何压缩输出信息的比特率,以提高线路复用率。本文在简述了有关这一领域的概况之后,着重阐述了三种语音波形编码的主要原理及其实时执行方式,即自适应差分脉码调制(ADPCM);子频带编码(SBC)及自适应变换编码(ATC)。前两种结构较简单,可用单片数字信号处理机(DSP)获得实时实现;后一种结构复杂,且进行分块处理,故实时执行时需采用数组处理机。三种方式分别将比特率压缩至32、16及9.6Kbit/s的范围内。文中对所涉及的硬件结构亦作了一定的介绍。     

用时域谐波定标的数字语音编码

本文给出了一种以9.6Kb/s数据率实时工作的新的数字语音编码器.该系统由时域谐波定标(TDHS)及子频带编码(SBC)两种不同的语音压缩算法组成.阐述了TDHS的基本原理,简述了几种不同的音调检测方法.本文最后对用DSP硬件实时执行该系统的几种方式作了讨论.     

光通信系统传输性能的对比分析

分析了载波抑制归零码(CSRZ)、差分相移键控(DPSK)和差分正交相移键控(DQPSK)三种调制格式的频域特性,并使用Optisystem软件对这三种码在40Gb/s光通信系统中的灵敏度、非线性效应和色散容限进行了对比。     

浅谈如何将VLAN技术应用于实践

陈海聪计算机网络技术的发展犹如戏剧舞台,你方唱罢我登台。从传统的以太网(10Mb/s)发展到快速以太网(100Mb/s)和千兆以太网(1000Mb/s)也不过几年的时间,性能先进的千兆网技术其核心交换机采用三层交换机,它能很好地支持虚拟局域网(VLAN)技术。本文着重介绍了VLAN的工作原理、优点和应用。     

基于枝节加载的内嵌式三频滤波器设计

利用λ/4(λ为波长)的多模谐振器(MMR),通过输入、输出端共用短路过孔,采用内嵌方式设计了一款WLAN频段(2.4GHz/5.2GHz)的双频滤波器,在此基础上,通过开路枝节加载方式,设计了一款中心频率为2.3GHz/3.3GHz/5.5GHz的三频段滤波器。滤波器尺寸为11mm×9mm,满足小型化的要求。利用HFSS12软件设计并仿真,得到验证结果。实验结果表明,双频段和三频段滤波器的损耗参数s11和s21均达到标准,可适用于无线通信系统。     

WZS—101型中速数据系统设备

IDR的概念最早于1978年提出,这是一种新的综合数字通信业务。国际通信卫星组织(INTELSAT)于1984年第59次董事会首次批准工作于A、B和C标准地球站IDR数字载波的性能要求。1986年又批准E_3、F_3和E_2、F_2标准站也可用IDR业务。提出IDR的目的是在传输56kb/s(对SGPC)和120mb/s(对TDMA)速率之间确定一种数字卫星通信方式。 IDR是英文intermediate data rate的缩写,译成中文为中速数据,其传输速率为64kb/s～44.736Mb/s_0~-IDR采用时分复用(TDM)、频分多址(FDMA)传输方式,本质上是TDM/PSK/FDMA。IDR基带为     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

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.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Cost-effective test solutions for smart card and other integrated flash applications

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.     

An improved parallel thinning algorithm with two subiterations

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.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

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.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

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.     

Study of waveguide coupling efficiency in hybrid silicon lasers

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.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.