排序方式: 共有34条查询结果,搜索用时 15 毫秒
1.
2.
The canonical form of multivariable linear system are determined by a set of invariants. For a given system, there may be several sets of invariants, therefore different canonical form, in essence, can be obtained. In this paper the nice selector determining the set of invariants has been discussed and a new conception of the nice selective pattern determining the nice selector has been proposed. We put stress on discussion of the natural nice selective pattern and the related canonical form, and made some comparisons with the well known Popov's canonical form. Finally, a identification algorithm have been given for identifing the canonical form corresponding to natural nice selective pattern. 相似文献
3.
柱上衍生反相高效液相色谱法测定疾藜提取物中痕量铅 总被引:1,自引:0,他引:1
提出了微波消解样品,在线衍生测定疾藜提取物中痕量铅的反相高效液相色谱方法.双水杨醛邻苯二胺为衍生剂,用DiamonsilTM C18色谱柱(4.6 mm×150 mm,5um)作为固定相,甲醇-水-衍生剂(64.5:34.0:1.5体积比)为流动相,检测波长为275 nm,柱温30℃.样品中铅在0.10~0.63 ng范围内呈线性,铅的平均回收率为99.5%,相对标准偏差(n=7)为1.8%. 相似文献
4.
进一步改进边界元方法以克服振动声辐射计算中解的非唯一性 总被引:3,自引:0,他引:3
章利用基于三次B样条插值的边界元方法,对振动体外部声辐射问题进行了研究,对CHIEF法及其改进方法作了进一步的改进,提出在加权余量意义下,通过把内部Helmholtz积分方程与其对内点坐标取导后的方程式作线性叠加,在域外构作的一个小体积块上进行积分以形成补充方程,经与表面Helmholtz积分方程相结合,来求解任意频率下的声辐射问题,并以脉动球和摆动球作为算例,说明本提出的方法能够有效地克服在特殊频率处解的非唯一性问题。 相似文献
5.
6.
7.
多变量线性系统的规范形是由一组不变量决定的。对给定的系统可以有不同的不变量组,因而也就有本质上不同的规范形。本文讨论了决定不变量组的适宜选择,并提出了在辨识中决定适宜选择的选择路线的概念。着重讨论了自然适宜选择以及相应的规范形,并和常见的Popov规范形作了比较。最后,对自然适宜选择下的规范形给出了整套辨识算法。 相似文献
8.
凤仙花植株不同部位微量元素含量的比较分析 总被引:2,自引:0,他引:2
The samples of pueraria lobata ohwi were digested by HNO3 + HClO4 .contents of the next trace elements Fe,Zn,Cu,Mn,Ca,Mg,Co,Cr,Ni,Cd,Pb and Al in the bloom,base,stem,and leaf of Impatiens balsamina have been determined by Flame Atomic Absorption method.The result show that the recovery is about 97.5%-103.2%,and the RSD<2.7%,with good accuracy and precision.The order of the content of the trace elements of high to low is as follows:leaf>stem>bloom>base.The importance of essential trace elements Zn,Fe,Mn,Cu for human each has a higher content.In addition,toxic trace elements such as lead,arsenic and cadmium are also found. 相似文献
9.
利用电磁理论对表面传导电子发射显示器件的单个子像素在笛卡尔坐标系内建立合理的电学物理模型,对内部电场强度和电势进行了深入研究,推导出了模型不同部分的面电荷密度、电场强度和电势的表达式.为了形象地表征其电学特性,利用MATLAB 6.5对电场强度和电势的分布情况进行了模拟,从理论上对模拟曲面给出了合理的解释,分析了子像素内部电子的发射机理和电学行为,并与电子多重散射模型和惯性离心模型进行了对比,解释了SED阳极电流形成的重要原因.在误差允许的范围内,本模型有关电场强度分布的结论与惯性离心模型一致. 关键词:表面传导电子发射显示遂穿效应面电荷密度电场强度 相似文献
10.