不变子空间的一个性质

给出了不变子空间的一个性质.应用此性质推广了文[1]中的定理1,并给出了几个推论.     

{Na2[μ2-(C6H4O2)2](C6H4OOH)2}4-的结构及其在固态合溶液中的NMR比较

The new compound （NH3CH2CH2NH3）2{Na2[μ2-（C6H4O2）2]（C6H4OOH）2} has been synthesized and characterized by elemental analysis, IR, UV, NMR and single crystal X-ray diffraction. The yellow crystals crystallized in the triclinic system with space group P-1 and a=0.6091（2） nm, b= 1.0274（3） nm, c= 1.2466（4） nm, α=89.073（6）°, β=89.376（6）°, γ=78.873（5）°, V=0.7653（4） nm^3, Z= 1, R1=0.0568, wR2=0.1198. Every sodium ion coordinates in trigonal prismatic fashion with two O atoms from a terminal chelating catecholato ligand and four O atoms from bridging P2 catecholato ligands, Two neighboring NaO6 trigonal prisms are face-shared and centrosymmetric with regard to the inversion center consisting of four tri-bridging O atoms to form a binuclear cluster {Na2[μ2-（C6H4O2）2]}^2- anion. The comparison of ^13C NMR spectrum of tlie complex in solid state with that in solution indicated that the rapid exchange between the bridging [μ2-（C6H4O2]^2- and terminal [C6H4OOH]^- ligands was present in solution.     

中间包液面波动的物理模拟

本文根据相似原理,按照13的模型,用水来模拟中间包内钢液的波动情况.在实验中,考虑到有无坝堰,不同坝堰组合,改变液面高度和引进浸入式水口等因素,用浪高仪来测量不同测点的波高,从而优化出最佳组合,找出了影响液面波动的敏感因素,从而为优化设计中间包、确定合理的拉速、减少卷渣的发生提供了有利的依据.     

对SERS衬底表面杂质的处理研究

化学沉积法制备的SERS衬底表面有时会引入杂质分子,所以在进行分子的SERS研究时,时有杂质的拉曼峰干扰。实验尝试利用KCl溶液浸泡除去银镜表面杂质的方法,取得了预期的效果。并把处理后的银镜用于分子的检测研究。这种方法简单易行,为分子的SERS研究提供了一条便利途径。     

La_(1-x)Sr_xMnO_3/TiO_2(x=0.2,0.15,0.04)异质pn结的整流特性

采用磁控溅射法制备的La1-xSrxMnO3(LSMO)/TiO2异质pn结表现出很好的整流特性.室温电流电压特性曲线显示随着Sr掺杂的增加,扩散电压增大,这可能由于Sr掺杂的增加导致载流子浓度增大所致.电流电压变温特性曲线显示随着测量温度的降低,扩散电压增大,这可能由于随着测量温度的变化导致界面电子结构的变化所致.值得提出的,异质pn结电阻随温度变化曲线表现出单层LSMO的金属绝缘相变特性,并且在低测量温度时表现出随着测量温度的降低结电阻增大,这可能是由于宽带隙的TiO2的引入导致.     

Proper application of a kind of matrix construction method in physical parameter identification of dynamic model

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硫酸盐对KDP晶体完整性的影响

本文利用高分辨X射线衍射技术,在"点籽晶"陕速生长法基础上,研究了掺杂K2SO4对KDP晶体锥面及柱面扇形结构完整性的影响.结果表明,在5×10-5的掺杂条件下,K2SO4对KDP晶体不同扇形区域的影响略有不同,其原因主要在于[SO42-]与KDP晶体各扇形相互作用不同有关.     

Homotopy solution of the inverse generalized eigenvalue problems in structural dynamics

The structural dynamics problems, such as structural design, parameter identification and model correction, are considered as a kind of the inverse generalized eigenvalue problems mathematically. The inverse eigenvalue problems are nonlinear. In general, they could be transformed into nonlinear equations to solve. The structural dynamics inverse problems were treated as quasi multiplicative inverse eigenalue problems which were solved by homotopy method for nonlinear equations. This method had no requirements for initial value essentially because of the homotopy path to solution. Numerical examples were presented to illustrate the homotopy method.     

变速轴向运动三参数模型黏弹性梁的稳定性

本文研究了速度变化的轴向运动三参数模型黏弹性梁在主参数共振以及组合参数共振范围内的稳定性.轴向运动梁的黏弹性本构关系采用三参数模型并引入了物质时间导数.运用渐进摄动法,直接求解梁的控制微分方程并导出了当运动参数激励频率接近某一阶固有频率2倍或接近某两阶固有频率之和时主参数共振和组合参数共振的稳定性条件.在解谐参数和激励振幅平面上,可以找出由于共振而产生的失稳区域.数值结果给出了梁的刚度系数、黏弹性系数及轴向平均速度对失稳区域的影响.在发生组合共振和主共振时,随着刚度系数E1的变大,失稳区域变小;刚度系数E2的变大,失稳区域变大.随着黏弹性系数的变大,失稳区域变小.发生组合共振时,随着平均速度的变大,失稳区域变小;发生主共振时,随着平均速度的变大,失稳区域变大.