Cu_4Ti晶体结构的高分辨电子显微术研究

Cu—Ti合金富Cu端的相结构一直为人们所关注。由于样品中难于避免多相共生及氧化存在,采用X射线测定结构时不同作者得到了不同的β相单胞:①Cu_3Ti结构(β_K),②Cu_4Ti结构(β_P,单胞参数为a=0.453,b=0.434,c=12.93nm,Pnma空间群)。此外,Ecob等依据电子衍射图支持了β_P—Cu_4Ti的结构,但却认为钛原子位置必须修正,才能解释(010)和(001)禁止衍射出现强度为此我们重新考察了Cu_4Ti的结构。Cu_4Ti的[100]与[001]衍射谱(图1a.b)中,对于OKL衍射当K+L为奇数以及对于HKO衍射当H为奇数均为消光,说明了滑移面n_(100)与a_(001)的存在。且Cu_4Ti相的所有衍射均可被β_P结构解释。为确定钛原子的位置,我     

准原位拉伸1420Al-Li合金的织构变化

1420Al-Li合金以其高比强度,高比刚度以及优良的低温性能,良好的耐腐蚀性和成型性而成为航空航天理想的轻质结构材料。本文对1420Al-Li合金进行了准原位拉伸试验,利用场发射扫描电子显微镜上安装的背散射电子衍射仪(EBSD-Channel5)对试样进行取向分析。EBSD结果表明:拉伸之前,1420Al-Li合金试样中存在弱织构{001}<100>;拉伸之后,弱织构消失,试样拉伸区存在近似于{001}<100>的{018}<018>织构。拉伸过程中晶粒绕晶带轴[001]和[010]发生转动,引起合金试样拉伸前后织构的变化。     

两种取向镍基单晶高温合金拉伸变形行为原位研究

本文基于课题组开发的原位拉伸测试系统，结合扫描电镜(SEM)与数字图像相关方法(DIC),研究了[001]和[314]取向的二代镍基单晶高温合金在室温下的拉伸变形断裂行为和微观结构演变之间的关系。结果显示，镍基单晶高温合金的力学性能具有各向异性。室温下镍基单晶高温合金的拉伸变形主要以滑移带剪切γ′相为主，其中[001]取向试样开启■、■滑移系，表现为交叉滑移；而[314]取向开启■滑移系，表现为单滑移。不同晶体取向激活的滑移系统及数量不同，滑移引起的塑性变形区扩展方向不同，由此造成不同的延伸率。室温下，不同取向的合金为类解理断裂机制。不同晶体取向的合金，开启滑移系的数目与难易程度不同，呈现出不同的断口形貌特征。     

时效Mn—Cu合金中的复相结构

锰含量大于～30at.%的Mn-Cu合金是一种具有良好机械性能的高阻尼合金。当代高技术条件下潜艇螺旋桨对高阻尼合金的需求,进一步推动了对该合金的研究[1]。对Mn-Cu合金的微观结构已有报道[2～4]。Mn含量>82at.%的合金室温淬火fcc结构的γ相发生四方转变,得到具有fct结构的微孪晶组织,合金具有高阻尼性能。当Mn含量低于约80at.%时,固溶态合金的阻尼本领(SDC)很低,须经中温时效处理才能获得高阻尼性能,时效态合金在TEM下显示织尼衬度。对织尼衬度所对应的微结构至今仍未得到令人满意的解释。本文根据电子衍射分析说明,时效Mn-Cu合金的微结…     

低温退火对铁硅合金中立方织构形成的影响

利用光学显微镜、SEM、TEM和EBSD分析研究了Fe-3.2%Si合金在低温初次再结晶退火和较低温度下二次再结晶退火后立方织构的形成。结果表明：采用低温退火可以在初次再结晶组织中获得（100）[001]织构及（hk0）[001]织构,并且这种初次再结晶组织在较低的二次再结晶温度下可演化成比较集中的立方织构。     

Cu—Zn—Al合金马氏体结构的电镜研究

一般认为Cu—Zn—Al合金电子浓度大于1.454时,马氏体为18R和2H两种类型的长周期结构,其基面(001)面上的原子有序排列,X射线分析初步判断18R型马氏体为单斜晶系,点阵参数为a=4.45A,b=5.29A,c=38.3A,β=88.7°。但X射线法难于肯定地排除它是基面原子无序排列,因而b与c都减半的9R结构,因为18R中的超结构反射强度非常弱。此外,还须区别β=90°的N18R与β(?)90°的M18R两种结构。为此,对Cu—Zn—Al合金中马氏体的结构进行了电子显微镜研究。     

Al—Li—Cu—Mg—Zr合金中Z相和T相的HREM观测

Al-Li-Cu-Mg-Zr合金以其低密度、高强度引起宇航界的广泛关注。该合金的组元较多,析出相很复杂,继T_2准晶相发现之后,M.Audier等人报导了一系列与其结构单元相近的其它合金相如R、C、Z、τ等相,至今对这些合金相结构关系的研究也取得了初步进展。本文主要研究该合金中Z相和T相的晶体缺陷及其结构关系。所研究合金的化学成份(wt·%)为Al-3.20Li-1.16Cu-4.04Mg-0.26Zr,热处理状态为510℃/0.5hr固溶处理,水淬,120℃×24hr时效。制成电镜薄样后在JEOL-2000EX电镜上作高分辨工作。     

化学镀Ni—Cr—P合金工艺研究

论述了化学镀Ｎｉ—Ｃｒ—Ｐ合金的可行性，指出：镀液的配制方法对镀层含铬量有较大影响，将Ｃｒ￣（６＋）还原为Ｃｒ￣（３＋），并形成Ｃｒ￣（３＋）活性络离子后再加入镀液，控制其它条件在最佳范围，可使镀层含铬量达１％以上。镀液中的铬合剂、稳定剂对镀层质量、镀层组成、沉积速度有较大影响。化学镀过程中应严格控制ｐＨ值，因为它对沉积过程有极大影响。化学镀Ｎｉ—Ｃｒ—Ｐ合金镀层具有较小的电阻温度系数，适用于电子零部件的表面处理。     

Bi—Sr—Ca—Cu—O系超导相中共生结构的会聚束观察

按照Bi:Sr:Ca:Cu=1:1:1:2的原子比制成Bi-Sr-Ca-Cu-O单晶样品,超导转变温度约为85K·采用会聚束及选区电子衍射的方法在 Philips EM420电子显微镜上对其结构进行研究,结果证明,这是一种正交结构·由图d的[001]带轴衍射图(EDP)可知单胞的a=5.4A,b=27.7A,而在c方向至少存在3种不同周期·较多的情况如图a所示:由全图及暗场的对称性可知其点群为mmm,箭头所指的一阶Laue环表明了[001]方向c=30A的周期排列。但在同一种样品中还发现了如图b和c中上下箭头所指的双重一阶Laue环现象,这显然是[001]方向不同周期排列共生所产生的效果计算表明,     

Ni—TM—P合金的自催化沉积

综述了获得成功沉积过程的自催化(化学镀)技术,像已被使用的Ni和Ni-P合金,以模具作为预备试样获得了优先的沉积,讨论了一系列Ni-P和Ni-TM-P自催化合金之间的关系及电化学和动力学参数,表面分析和镀后加工。     

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.     

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.     

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.     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

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.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

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.     

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