Traveling-wave piezoelectric linear motor Part I: the stator design.

A new type of piezoelectric linear motor incorporating a traveling wave has been developed. The linear motor is comprised of a stator and a carriage. The stator design, which consists of a meander-line structure and gear teeth mounted on the meander-line structure, is the focus of this article. The meander-line structure is constructed with bimorph actuators arranged in a line. These actuators are driven by two phased sets of alternating current (ac) in order to generate a traveling wave. The traveling wave is transferred to the gear teeth, by which the carriage is driven. Modeling of the stator is derived by use of a strain energy method. The performance of various materials is evaluated by analytical and experimental methods. The analytical and the experimental results are quite approximate. Modal analysis is investigated using ANSYS. Appropriate modes associated with ultrasonic levels of resonant frequency are selected to obtain desired motion and to enhance the output performance. Surface speed for various applied input voltage are studied and indicate a nearly linear relationship. The stator in combination with the carriage makes up the linear motor.     

中国石油石蜡基橡胶油系列产品在橡胶工业中的应用

中国石油研制生产的健康环保型石蜡基橡胶填充油系列产品，具有浅颜色、低芳烃、高饱和烃含量等特征，是中国石油的优质特色产品。该系列产品在国内橡胶行业中已得到广泛应用，其中，KP6025、KP6030石蜡基橡胶油通过了2001年中国石油润滑油公司的鉴定，该产品的研制成功，填补了这一领域的国内空白，产品性能优于国外同类产品，为国内橡胶企业的产品结构调整创造了条件，推动了我国橡胶产业向国际先进水平的发展，具有重大的经济和社会效益。主要综述了中国石油石蜡基橡胶油的应用与评价情况。     

有环境约束时完成一族跟踪任务的力控制

本文为工业机器人提出了一种极点配置控制法，这种控制方法的优点有：一是它的积分作用消除了机器人的微小扰动和稳态误差；二是能任意设置系统的极点，因此能保证闭环系统的稳定性和规定状态变量的暂态响应；三是加入了加速度反馈，抑制了由电枢电感所引起的机械手的振动，最后，给出了ＰＵＭＡ５６２机器人的计算机仿真和实验结果验证了此控制法的有效性。     

不完全信息下的最终报价仲裁

基于争议双地仲裁人的裁决值有不同的概率估计，而这些估计是双方共同知识这一前提分析最终报价中仲裁，把它构造成一个不完全信息的非零和对策模型。然后给出了局部、全局Ｎａｓｈ平衡报价策略存在唯一的充分条件，最后探讨了双方认识存在的差异对争议人报价行为的影响。     

Preparation and Properties of Sintering Additives Coated Si3N4 from Heterogeneous Nucleation Processing

The sintering additives such as Al2O3 and /or Y2O3 were coated on the surfaces of Si3N4 particles via heterogeneous nucleation processing using a buffered pH solution as the precipitation reagent .They nucleated and grew only on the surfaces of Si3N4 and did not form sol particles in solution by TEM observation .The isoelectric point(IEP) of coated Si3N4 was different from that of as-received Si3N4.The IEP of Al(OH)3-coated Si3N4 occurred at pH8.4, which is close to that of alumina .When Al(OH)3-coated Si3N4 particles were coated with Y(OH)3,the IEP of coated Si3N4 powder shifted from pH8.4 to pH9.2 ,similar to that of yttria.In addition ,the rheological data showed that Al2O3 and /or Y2O3 coated Si3N4 suspension is nearly Newtonian and that added Si3N4 suspension shows a shear rate thinning behavior.     

超声波在金属凝固中的应用与发展

简要介绍了超声波及其基本特性，综述了高能超声对金属凝固过程作用方面的研究和应用状况，提出超声处理是改善金属凝固组织，提高力学性能的有效方法，并对21世纪超声凝固细晶技术的前景进行了展望。     

磨损自补偿添加剂在成品油中的摩擦学效应

利用四球试验机考察了二聚酸－3－氯－2－羟基丙单酯（DAE）在4种成品油中的摩擦学性能。试验结果表明，DAE添加剂在L－HM68液压油和L－DAB100空压机油中具有良好的适应性，使其承载能力增强，摩擦系数降低及耐磨性增强；DAE在L－CKE涡轮蜗杆油中使耐磨性增强；DAE在L－CKC150齿轮油中虽使承载能力提高，减磨性增强，但有使耐磨性减小的趋势，说明DAE在不同的油中有不同的性能。     

热敏电缆在拉拔减径工艺过程中的性能变化

在拉拔减径工艺的初始阶段，装填于热敏电缆中的氧化物陶瓷热敏材料粉的体积将发生收缩，随后体积不再发生变化。对于不经过热处理的样品，理论分析和实验结果表明，体积收缩停止后，其每米电阻值不随尺寸变化而改变。由于安装等因素引起的芯线电极的位置偏差不公带来样品电阻较大的变化。对于经过热处理的样品，其电阻值在热处理前后及拉拔减径过程中都有较大的变化（可达几个数量级），变化规律较为紊乱。实验分析发现，热处理后的     

Extraction of Anthocyanin Pigments from Purple Sunflower Hulls

The anthocyanin pigments in hulls of purple sunflower seeds were extracted using three solvent systems, 50:1:49 ethanol-acetic acid-water (EAW), 0.01M acetic acid (AAc), or water containing SO₂. Solvent, extraction time, size of ground hulls, pH of extracting solvent, hulls/solvent ratio, and concentration of SO₂ in water, were investigated. All were significant factors affecting yield of extracted anthocyanins. EAW and SO₂ were more effective extractants than AAc. Optimum conditions from response surface optimization for the extraction with sulphurous water were: SO₂ at 200 mg/L, hull size 20 mesh, extraction time 5 min at 22°C, and solvent/hulls ratio = 20.     

The As-prepared surfaces of C-axis-oriented Nd1Ba2Cu3Oy thin films characterized using scanning probe microscopes

Recently, superconducting Nd₁Ba₂Cu₃O_y (Ndl23) thin films with high superconducting transition temperature (T _c) have been successfully fabricated at our institute employing the standard laser ablation method. In this paper, we report the results of surface characterization of the Nd123 thin films using an ultrahigh vacuum scanning tunneling microscope/spectroscopy (UHV-STM/STS) and an atomic force microscope (AFM) system operated in air. Clear spiral pattern is observed on the surfaces of Nd123 thin films by STM and AFM, suggesting that films are formed by two-dimensional island growth mode. Contour plots of the spirals show that the step heights of the spirals are not always the integer or half-integer number of thec-axis parameter of the structure. This implies that the surface natural termination layer of the films may not be unique. This result is supported byI-V STS measurements. The surface morphology of the Nd123 thin films is compared with that of thec-axis-oriented Y₁Ba₂Cu₃S_y thin films. Surface atomic images of the as-prepared Nd123 thin films are obtained employing both STM and AFM. STS measurements show that most of the surfaces are semiconductive. The results of STS measurements together with the fact that we are able to see the surface atomic images using scanning probe microscopes suggest that exposure to air does not cause serious degradation to the as-prepared surfaces of Nd123 thin films.