Adaptive motion control using neural network approximations

In this paper, we present a new adaptive technique for tracking control of mechanical systems in the presence of friction and periodic disturbances. Radial Basis Functions (RBFs) are used to compensate for the effects of nonlinearly occurring parameters in the friction and periodic disturbance model. Theoretical analysis, such as stability and transient performance, is provided. Furthermore, the performance of the adaptive RBF controller and its non-adaptive counterpart are compared.     

斗晏水电站混凝土面板堆石坝趾板设计

阐述了江西省重点建设项目斗晏水电站混凝土面板堆石趾板设计，并重点介绍较大断层上趾板设计处理方式。     

纵横波测井资料在储层评价中的应用

将弹性波基础理论，Gasman理论，Biot理论和实验研究结果相结合，探讨了沉积岩地层中速度和弹性模量，弹性模量和孔隙度，剪切模量和孔隙度，速度和孔隙度，孔隙度和Biot系数之间的关系，利用从各种声学测井资料中提取出的P波和S波时差（或速度）定量评价地层孔隙度和骨架物质，辅以泥质指示测井曲线，可以计算地层孔隙度，饱和度，岩性等参数，在M，Krief方法的基础上，采用优化算法寻求适合于任何岩性地层的孔隙度与Biot系数之间的关系式，提高了Biot系数的计算精度，该评价方法有坚实的实验基础和理论基础，评价结果与实验室岩心分析数据吻合。     

中国石油未来油气勘探重点领域分析

根据近几年来的研究认识与勘探成果分析,未来几年中国石油油气勘探主要集中于如下五大重点领域:大面积低渗透岩性油气藏、成熟区复杂隐蔽油气藏、前陆盆地复杂构造油气藏、海相碳酸盐岩油气藏和渤海湾滩海第三系油气藏。     

MEMS光开关及其与光纤组装方式的研究

光开关是一种在光路中应用极其广泛的光无源器件,可用于扫描、投影、通讯等多种不同的领域,其中用于全光通讯中连接光纤之间的光开关日渐成为人们关注的焦点.高性能、低成本、又能大量生产的MEMS光开关很好地满足了全光网络对器件的要求.本文对这种MEMS光纤光开关的类型、特点以及研究现状进行了介绍,并给出了MEMS光开关与输入输出光纤的组装与自组装以及主要方式.     

Analysis on the effectiveness of the 20-H rule for printed-circuit-board layout to reduce edge-radiated coupling

This paper presents the quantified study of the electromagnetic radiation mechanism of the 20-H rule using a numerical approach that has not yet been systematically addressed. The 20-H rule is a rule-of-thumb layout technique recommended to minimize radiated fields propagating from the edges of a printed circuit board (PCB) coupling onto nearby structures. Propagating electromagnetic fields may corrupt adjacent cable assemblies, sheet metal enclosures, and aperture openings. The magnitude of this design rule is investigated using the full-wave finite-difference time-domain (FDTD) method. An analysis on whether benefits exist from use of this rule is examined and under what conditions the rule is valid when correctly implemented. The purpose of this paper is to provide insight into the validity of the 20-H rule, recognizing that every PCB will have different simulation results. FDTD is used to capture a snapshot view of field propagation. This view allows one to determine the validity of the 20-H rule at a single point of time within a dynamic structure and what may be expected when digital components are finally added to a PCB assembly, which generally negates simulated results.     

Influence of CYP3A5 polymorphism on tacrolimus blood concentrations in renal transplant patients

Objective Tacrolimus is an immunosuppressive drug with narrow therapeutic range and wide interindividual variation in its pharmacokinetics. Tacrolimus is a substrate of cytochrome P450(CYP)3A5. The aim of this study was to evaluate whether the A6986G polymorphism is associated with tacrolimus concentration /dose ratio. Methods Fifty-two Chinese renal transplant patients were enrolled in this study. Their body weight, dosage and concentration of tacrolimus were observed. CYP3A5 genotype was determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Results A significant association was found between tacrolimus levels per dose/kg/d and CYP3A5 gene A6986G polymorphism (P<0.001). The CYP3A5 * 3 * 3 patients have a significantly higher tacrolimus level/dose than CYP3A5 * 1 * 1 and CYP3A5 * 1 * 3. Conclusions CYP3A5 gene A6986G polymorphism is associated with tacrolimus pharmacokinetics and dose requirements. Pharmacogenetic methods could be employed prospectively to help the dose selection and to individualize immunosuppressive therapy according to the result. Foundation item: Project (03GZ3072) supported by the Science and Technology Department of Hunan Province; project (2004035206) supported by the China Postdoctoral Foundation and project (30300383) supported by the National Natural Sciences Foundation of China     

A new colloidal precursor cooperative conversion route to nanocrystalline quaternary copper sulfide

A novel milk-like Cu-thiourea colloid has been synthesized. Nanocrystalline quaternary copper sulfide Cu₂FeSnS₄ was obtained through the Cu-thiourea colloidal precursor cooperative conversion route at low temperature. The samples were characterized by means of X-ray powder diffraction, transmission electron microscopy, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, and X-ray energy dispersive spectroscopy techniques. The reaction details and features were described and discussed.     

马尾松木材中性脱脂工艺的研究

采用全因素试验法，对马尾松木材进行过热乙醇溶液脱脂处理，以获取马尾松木材高效脱脂工艺技术。试验结果显示：（1）脱脂温度对马尾松松脂溶出量的影响极显著，且溶出量随着脱脂温度的升高而增大；（2）脱脂时间对马尾松松脂溶出量的影响极显著，且溶出量随着脱脂时间的延长呈先增大后减小的趋势；（3）脱脂浴比对马尾松松脂溶出量的影响极显著，且溶出量随着脱脂浴比的延长呈先增大后减小的趋势；（4）利用过热乙醇溶液对马尾松木材进行脱脂，其最佳工艺是脱脂时间为130℃、脱脂时间为8h、浴比1：8。