An efficient controller structure with minimum roundoff noise gain

Based on a polynomial operator approach, a new sparse controller structure is derived, which is actually an improved version of the recently proposed structure [Li, G. (2004). A polynomial-operator-based DFIIt structure for IIR filters. IEEE Transactions on Circuits and Systems II, 51, 147-151]. The performance of the proposed structure is analyzed by deriving the corresponding expression of roundoff noise gain and the problem of finding optimized sparse structures is solved efficiently with a genetic algorithm (GA). A numerical example is given, which shows that the newly developed structure can achieve much better performance than some well-known structures and particularly outperforms the traditional optimal fully parametrized realization greatly in terms of reducing roundoff noise and implementation complexity.     

澳大利亚进口焦煤煤质特性与结焦特性研究

通过质量检测、煤的岩相分析和20kg试验焦炉炼焦试验，对澳大利亚两种进口焦煤诺维茨煤和峰景煤的煤质和结焦特性进行了研究，两种进口焦煤低灰、低硫，为单一煤层煤，煤质稳定，配煤炼焦有利于焦炭质量稳定。峰景煤和国内柳湾煤的结焦性能相当，诺维茨煤的结焦性能与国内恒山煤和祁县煤的结焦性能接近。     

镀锌层上有机物无铬钝化涂层的耐蚀性

选择了一种无毒的水溶性丙烯酸树脂（AC）加入至钼酸盐、磷酸盐中（M）得到一种钝化液（ACM），对镀锌层进行钝化处理以代替有毒的铬酸盐钝化。通过盐雾试验、扫描电镜、电化学测试等手段，研究了该纯化膜的耐蚀性及耐蚀机理。结果表明，热浸镀锌层采用该无毒钝化液进行钝化，可以推迟镀锌层出现白锈的时间，其抗蚀性已接近铬酸盐钝化水平；ACM钝化膜耐蚀性的提高是由于钝化膜中的钼酸盐与丙烯酸树脂产生交联作用，抑制钝化膜裂纹的扩展，同时由于膜层中钼酸盐的缓蚀作用，提高了镀锌层的抗蚀性。     

T型薄壁管节点应力集中系数有限元分析

通过有限元的方法,分析了T型薄壁管节点受平面内弯矩作用下的疲劳行为,得到了应力最大值的位置和拟合出用于预测T型薄壁管节点受平面内弯矩作用下的应力集中系数的参数公式。     

由拱管组成的复合管段固定支架受力计算

根据工程设计的实践，介绍了由拱管和波纹补偿器所组成的复合管段的固定支架受力计算方法和注意事项。     

Bone growth and bone development in the presence of implants or after induced leg-lengthening studied using the Oxford Scanning Proton Microprobe

To respond to varying environmental demands the bone tissue in the body is under continual reconstruction throughout life. It is known that metallic elements are important for maintaining normal bone structure, but their roles are not well understood. More information about the effects of metal excess or deficiency is needed to help in the development of metallic bone implants and to improve the treatment of bone fractures and defects. The Oxford Scanning Proton Microprobe (SPM) is being applied in two studies involving metal ions in bone: (1) bone regrowth and bonding to titanium bone implants may be influenced by diffusion of Ti ions into the bone. We are using microPIXE to determine the metal ion content of bone developing in contact with implants of pure Nb, Ti and Ti alloys. (2) Bone lengthening as a surgical procedure is induced by fracturing the bone and allowing it to heal with a small gap between the fractured ends created by the use of external fixators. The gap can be slowly increased during the healing process to stimulate the production of new bone. The enzymes and other constituents of the developing bone need certain metals for their function. Using experimental animals we have studied the concentrations of the metals and whether a deficiency of trace metals limits the optimum rate of bone lengthening.     

论色彩心理学在环境艺术设计中的应用

本文主要讨论环境艺术设计中如何利用色彩心理学进行色彩设计,安置基调色、配合色以及各种色彩的调配。     

Adaptive fuzzy decentralized control for nonlinear large-scale systems based on high-gain observer

An adaptive fuzzy decentralized backstepping output-feedback control approach is proposed for a class of nonlinear large-scale systems with completely unknown functions,the interconnections mismatched in control inputs,and without the measurements of the states.Fuzzy logic systems are employed to approximate the unknown nonlinear functions,and an adaptive high-gain observer is developed to estimate the unmeasured states.Using the designed high-gain observer,and combining the fuzzy adaptive control theory with backstepping approach,an adaptive fuzzy decentralized backstepping output-feedback control scheme is developed.It is proved that the proposed control approach can guarantee that all the signals of the closed-loop system are semi-globally uniformly ultimately bounded(SUUB),and that the observer errors and the tracking errors converge to a small neighborhood of the origin by appropriate choice of the design parameters.Finally,a simulation example is provided to show the eectiveness of the proposed approach.     

基于启发式规则优化的网页元素提取方法

网页信息提取方法中的启发式规则,是识别网页标签信息、利用网页节点分析结果、针对网页不同内容、完成信息提取的重要手段。本研究在对现有启发式规则进行研究分析的基础上,提出了几种优化的启发式规则,实现对网页标题、发布时间、来源以及正文内容等元素信息的精准提取。本研究进一步提出了运用编辑距离算法实现正文内容提取准确率的判定,并提出阙值优化方法,克服了正文提取中噪声节点多、内容识别不完全的缺陷,大大提高了提取的准确度。