D/A转换器及其应用

文中述及D／A芯片的进展、D／A模块、芯片的特点、应用，对设计与使用有较大参考价值。     

Analysis of dispersion properties in square hollow fiber

A hollow fiber with new cross section was studied by means of a numerical simulator based on the finite-difference time-domain (FDTD) method. Its guiding mechanism was the right angle internal reflection. Results show that light can be confined into the air core due to the right angle guiding mechanism that was implemented with the hollow square glass. Distributions of the transverse electric field intensity as well as dispersion properties of the fundamental mode were given. This fiber can be used in optical communication, gas sensing, enhanced Raman scattering, CO/sub 2/ laser guidance, and particle transport.     

拔尖人才培养模式下的工程图学教学研究

为适应拔尖创新人才培养的需要,提高工程图学教学效果,本文提出了工程图学课程的改革方案,进行了实践研究。采用中英双语教学模式,开展基于构型创新设计的工程图学实验课与自主型交互式机械设计制图实验课。培养了学生的创新思维与工程意识,锻炼了其动手实践能力,提高了学生团队合作素质,为专业知识的学习打好基础,取得了理想的教学效果。     

基于多目标决策方法的反应离子刻蚀机约束环优化设计研究

从反应离子刻蚀设备腔室内部结构细节角度出发,研究腔室约束环对以450 mm为代表大晶圆尺寸刻蚀机流场影响。与同类研究相比,本文旨在突出研讨仿真模型的精确性与边界条件比较设置准则的重要性。本文首先介绍刻蚀机腔室约束环的结构及其功能并提出高精度粘度修正的实现方法并计算腔室流体气压分布。提出了腔室气压分布的多目标问题,采用遗传算法求解,并通过多目标决策对优化结果进行评价和排序,得到最适合的优化结果。最后,给出约束环设计结果并得出约束环可以优化腔室内气流分布轮廓的结论。     

刻蚀机装备设计中的序贯试验设计方法研究

450mm晶圆刻蚀机开发中大量应用确定性仿真来模拟腔室内部物理、化学环境,并通过仿真结果指导装备结构的详细设计。为控制仿真试验的采样规模以缩短开发周期,本文详细介绍一种新型的基于采样密度和非线性度的序贯设计方法。此方法通过蒙特卡洛方法,在设计空间中获得采样密度信息,进而对低采样密度区域增加采样点。另外,通过对每个采样的领域进行发掘,以获得采样的梯度和非线性度信息,进而对高度非线性的区域增加采样点。以450mm刻蚀机约束环设计模型和Goldstein-Price模型为背景,采用拉丁超立方和新型序贯设计方法同时采样,以代理模型精度和特征捕捉能力两个角度来对比采样结果的优劣,结果证明,在达到同样精度的前提下,新型序贯设计方法能有效减小采样规模,符合刻蚀装备设计的需要。     

Numerical analysis of LEC growth of GaAs with an axial magnetic field

A set of numerical analyses for momentum and heat transfer for a 3 in. (0.075 m) diameter Liquid Encapsulant Czochralski (LEC) growth of single-crystal GaAs with or without an axial magnetic field was carried out using the finite-element method. The analyses assume a pseudosteady axisymmetric state with laminar flows. Convective and conductive heat transfers, radiative heat transfer between diffuse surfaces and the Navier-Stokes equations for both melt and encapsulant and electric current stream function equations for melt and crystal are considered together and solved simultaneously. The effect of the thickness of encapsulant, the imposed magnetic field strength as well as the rotation rate of crystal and crucible on the flow and heat transfer were investigated.     

C-S-H凝胶的制备与性能研究

利用水热合成法制备了C-S-H凝胶,重点研究了不同的制备工艺、原材料与钙硅比对C-S-H凝胶结构的影响。经过详尽的X衍射(XRD)与核磁共振(NMR)分析表明,制备的样品都具备C-S-H凝胶的峰型特征;活性反应法相对于沉淀反应法制备的C-S-H凝胶层间距小、聚合度低;证实了C-S-H凝胶的层状结构,且层间距随钙硅比的增大而减小;Q~2/Q~2值与直链平均长度随钙硅比的增大而减小。     

混合氨基酸铜络合物的杀菌活性

针对各种单一氨基酸铜络合物、混合氨基酸铜络合物及一些重金属混合氨基酸络合物，分别测定了它们对白粉病原菌、稻瘟病原菌和小麦根腐病原菌的毒性．实验结果表明，在混合氨基酸铜络合物中起主要杀菌作用的是谷氨酸铜、甘氨酸铜、丙氨酸铜和苏氨酸铜．     

Characterization of prolidase activity using capillary electrophoresis with tris(2,2'-bipyridyl)ruthenium(II) electrochemiluminescence detection and application to evaluate collagen degradation in diabetes mellitus

A new method for prolidase (PLD, EC 3.4.13.9) activity assay was developed based on the determination of proline produced from enzymatic reaction through capillary electrophoresis (CE) with tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)3(2+)] electrochemiluminescence detection (ECL). A detection limit of 12.2 fmol (S/N = 3) for proline, corresponding to 1.22 x 10(-8) units of prolidase catalyzing for 1 min was achieved. PLD activity determined by CE-ECL method was in agreement with that obtained from the classical Chinard's one. CE-ECL showed its powerful resolving ability and selectivity as no sample pretreatment was needed and no interference existed. The clinical utility of this method was successfully demonstrated by its application to assay PLD activity in the serum of diabetic patients in order to evaluate collagen degradation in diabetes mellitus (DM). The results indicated that enhanced collagen degradation occurred in DM.     

肯基亚克8102井钻井液技术

为解决肯基亚克盐下油田压力高、温度高、矿化度高、密度高等钻井液技术问题,在对该地层特性、岩性和储层特点进行研究的基础上,研发出了适合该区域的两性离子聚磺盐水钻井液.现场应用表明,该钻井液较好地解决了高密度盐水钻井液流变性、盐层井壁稳定、漏喷同层和高密度盐水钻井液的防卡等问题,实现了全井无事故及复杂情况的记录;井径规则,平均井径扩大率为5.62%;润滑防卡措施效果明显,起钻最大提升阻力不超过10t,无任何阻卡情况.肯基亚克8102井钻井液的流变性得到明显优化,流变参数显著降低,与未采用该技术的邻井235井相比,表观黏度降低42%,塑性黏度降低40%,动切力降低46%,静切力降低58%,可将密度为1.95 g/cm<'3>的钻井液的黏度维持为70～90 s.