智能型电子式变频电动执行器及其应用

针对原有电动执行器只有以低速运行，通过极强的微调才能修正微小偏差这一缺点，提出智能型电动执行器与各种阀体譬合，利用数字化变频技术，改造目前采用模拟技术的电动执行器，使之具有变速运行、动态响应块，调节定位精度高、稳定性好，故障率低、使用寿命长和应用场合广泛的特点。     

1,5-己二烯交联烯烃聚合物的合成及其抗剪切稳定性

以金属配合物为催化剂、1,5-己二烯为交联剂,采用本体聚合法合成了交联超高相对分子质量烯烃类聚合物(简称交联聚合物)。用傅里叶变换红外光谱、核磁共振、凝胶渗透色潜表征交联聚合物的结构和相对分子质量。用旋转黏度计和超声波仪研究了1,5-己二烯用量对交联聚合物溶液表观黏度的影响及交联聚合物的相对分子质量对交联聚合物溶液抗剪切稳定性的影响。实验结果表明,在最佳聚合条件(单体80mL、助催化剂0．4mL、CS-1催化剂0．090g、1,5-己二烯0．40mL、0℃、24 b)下所合成的交联聚合物的重均相对分子质量为7．7×106,数均相对分子质量3．6×106。加入少量1,5-己二烯能提高交联聚合物的抗剪切能力,同时也能提高交联聚合物的相对分子质量。交联聚合物的相对分子质量越大,抗剪切稳定性越好。1,5-己二烯用量约为0．1 mL时(单体40 mL),交联聚合物溶液的表观黏度达到最大值(16．8 mPa·s)。     

基于CVSD编码的无线语音系统方案的设计

简要介绍了连续可变斜率增量(CVSD)调制的原理。与目前应用较为广泛的其它语音编码方式相比较,CVSD拥有更优的数字特性。着重介绍了由CML公司研制开发的基于CVSD的语音编码芯片———CMX649的特点及相关的应用方式。CMX649能够成功地应用在广泛的语音编码系统中,尤其适合无线语音系统应用。在此基础上,给出了一种实用性很强的低成本、低功耗无线语音系统的设计与应用方案。该方案可提供清晰可靠的语音传输,可广泛应用于农村地区,具有广阔的市场空间。     

水泥浆失水制约下套管与井眼间隙的研究

通过对水泥浆失水规律的室内试验分析以厦对注水泥顶替过程中水泥浆失水桥堵套管与井眼间隙问题的研究，建立了顶替过程中滤失层不发生水泥浆失水而桥堵环形空间的临界失水量计算模型，提出了调配水泥浆失水性能和确定合理套管井眼间隙的具体方法，对注水泥现场施工和井身结构设计具有一定的指导意义。     

RF磁控溅射制备钛酸锶钡BST纳米薄膜

钛酸锶钡(BST)薄膜作为一种高K介质材料在微电子和微机电系统等领域具有广阔的应用前景,人们已对BST薄膜的制备工艺技术和介电性能进行了大量的研究。BST纳米薄膜的制备工艺直接影响和决定着薄膜的介电性能(介电常数、漏电流密度、介电强度等)。对RF磁控反应溅射制备BST纳米薄膜的工艺技术进行了综述。从溅射靶的制备、溅射工艺参数的优化、热处理、薄膜组分的控制,及制备工艺对介电性能的影响等方面,对现有研究成果进行了较全面的总结。     

Corrosion morphology of AZ91D exposed in an atmospheric environment

The focused ion beam technique was employed to investigate the atmospheric corrosion morphology of AZ91D. It was found that the α matrix of the alloy was preferentially corroded in the areas adjacent to intermetallic phases. The most interesting finding was that the corrosion products in corrosion cavities were pelletlike, which has never been reported before.     

Optimal Spectral-Galerkin Methods Using Generalized Jacobi Polynomials

We extend the definition of the classical Jacobi polynomials withindexes α, β>−1 to allow α and/or β to be negative integers. We show that the generalized Jacobi polynomials, with indexes corresponding to the number of boundary conditions in a given partial differential equation, are the natural basis functions for the spectral approximation of this partial differential equation. Moreover, the use of generalized Jacobi polynomials leads to much simplified analysis, more precise error estimates and well conditioned algorithms.Mathematics subject classification 1991. 65N35, 65N22, 65F05, 35J05     

Structure, properties, and thermal stability of nanocrystallite Fe-Ti-N soft magnetic films

We deposited Fe-Ti-N magnetic films with a high sputtering power of 7 W/cm/sup 2/. When the composition of the films was in the range of Fe-Ti(3.9 at.%)-N(8.8 at.%) to Fe-Ti(3.3 at.%)-N(13.5 at.%), the films were composed of /spl alpha/' and Ti/sub 2/N precipitates. With the addition of nitrogen, 4/spl pi/M/sub s/ became higher than that of pure iron, reaching a maximum of 23.8 kG. At the same time, H/sub c/ was reduced to a minimum of 1.12 Oe. The best films can meet the needs of the recording head in dual-element giant magnetoresistive/inductive heads, yielding high storage density (10 Gb/in/sup 2/). The incorporation of N in /spl alpha/-Fe brought about the /spl alpha/' phase with its higher saturation magnetization. Ti additions inhibited the equilibrium decomposition /spl alpha/'/spl rarr//spl alpha/+/spl gamma/'. Because H/sub C//sup D//spl prop/D/sup 6/, where D is average grain diameter, grain size control is very important. The nitrogen induces severe distortion of the /spl alpha/' lattice, which can cause the grains to break into pieces and reduce the grain size. High sputtering power also led to the formation of fine grains, with diameter in the order of 14 nm. Probably Ti/sub 2/N is preferentially precipitated on the grain boundary, pinning the grain boundary and stabilizing the grain size during high-temperature heat treatment. The temperature limit for stability of the structure and its associated low coercivity was not less than 520/spl deg/C.