一、设连续系统函数H(s)在虚轴上收敛,其幅频响应函数为H(j),试证幅度平方函数 H()?=H()(-s) sjo 二、其离散系统的系统函数z2+3z+2H(z)=2z-(K-1)z+1

研究了一种通过水热碱法-酸液回流-煅烧，从含钛电炉熔分渣中分离提取、制备纳米结构六钛酸钾晶须材料的新方法.采用扫描电子显微镜、透射电子显微镜、X射线衍射、X射线荧光光谱等表征手段，详细探讨了煅烧过程中钛钾摩尔比、煅烧温度、保温时间和水浸对最终产物物相和微观形貌的影响.含钛电炉熔分渣在水热温度为200℃，水热反应时间为24 h，碱液浓度达12 mol·L-1时，经酸液回流后所得偏钛酸呈一维单晶纳米棒状结构.随着钛钾摩尔比从1.50增加至1.75，煅烧温度从800℃升高到1100℃，保温时间从0.5h延长至7h，制备得到的六钛酸钾晶须的纯度、结晶性及长径比逐渐提高.当钛钾摩尔比为1.75，煅烧温度为1100℃，保温5 h，水浸2 h后可制备得到尺寸均一的六钛酸钾纳米晶须

针对线性不确定系统,研究了其执行器失效情况下鲁棒容错H∞动态输出反馈控制设计问题.基于连续型执行器故障模型,利用线性矩阵不等式(LMI)方法提出了线性不确定系统动态输出反馈H∞容错控制器存在的充分条件,给出了动态输出反馈H∞控制器的设计方法.所获得的控制器不仅能使故障系统鲁棒稳定,并且能达到给定的H∞性能指标.仿真实例证明了所提出设计方法的有效性

基于二次稳定性理论,研究了不确定离散时滞系统的鲁棒H∞控制问题.采用线性矩阵不等式的方法,讨论了有记忆状态反馈鲁棒H∞控制问题,得到了确保鲁棒H∞控制器存在的充分条件和H∞状态反馈控制器的设计方法.最后举例说明了该方法的正确性

The difference betWeen the systems of CaO-SiO2-H2O and CaO-SiO2-Al(OH)3-H2O, was studied,especially the effect of Al3+ on the crystallinity of tobermorite was focussed. As a result, in the system of CaO-SiO2-H2O, tobermorite formed early, howevey, with reaction time forward, tobermorite was replaced by xonotlite. So far as CaO-SiO2-Al(OH)3-H2O was concemed, hydrothermal reaction was carried out under the same condition as CaO-SiO2-H2O to study the morphological changes of tobermorite crystals. It was found that Al3+ accelerated the crystal growth of tobermorite to some extent and was in favor of platy crystals. Moreover, with the Al3+ content increasing in the starting material, the morphology of tobermorite did not change magnificently, but platy crystals became more and more eminent. As soon as the Al2O3