二重高阶对称破缺分歧点和它们的数值确定

本文考虑带Z_××Z₂对称性的两参数非线性的二重高阶对称破缺分歧点。利用对称性,我们提出了相应的正则扩张系统来确定这类分歧点。同时指出存在两条平方音叉式分歧点的道路通过该点。     

14N核四极共振自旋系统自旋-晶格弛豫时间的测量

¹⁴N核四极共振自旋系统的自旋-晶格弛豫是一种双指数弛豫。本文介绍了¹⁴N核四极共振自旋系统的自旋-晶格弛豫时间的3种测量方法,利用可变多面体方法对实验数据进行拟合,获得了¹⁴N核四极共振自旋系统的自旋-晶格弛豫时间T_1s和T₁₁,对有关文献中关于核四极共振弛豫时间的测量的3个观点提出了质疑。     

分析结构跳跃问题的自适应参数增量迭代方法

通过对Riks切线弧长法和Crisfield圆弧长法的综合及改进,本文提出分析结构跳跃问题的自适应参数增量迭代方法,并建立相应理论基础。最后文中给出中心分布压力作用下圆底扁球壳跳跃问题的数值结果,以验证它的有效性。     

Uniform strength design of beams with non-zero minimum flexural rigidity under multiple loadings

The analytical method for uniform strength design (U.S.D.) of statically indeterminate beams is extended to deal with a preassigned constraint of non-zero minimum flexural rigidity and multiple load cases. And a numerical method of finding the U.S.D. is presented. Therefore we have a uniform procedure of solution of U.S.D. to beams with arbitrary cross-sectional shape and acted upon by several loadings and subjected to the constraint of minimum flexural rigidity.     

Numerical analysis of edge effect in laminated composite structures

In order to further study free edge effect in composite laminates, a new method is developed. This method is based on the perturbation and modified method of least square. In this paper, we emphatically discuss the solution within the boundary layer region, the socalled inner solution. As an example, we will discuss structures composed of two and four symmetric laminates. Project Supported by the Science Fund of the Chinese Academy of Science.     

S树兰烯( 烯)类似物的合成

本文报导了树兰烯(即钴钯烯)的几个类似物(6a-d和7a-d)的合成, 并讨论了有关这些化合物的形成反应的构象效应。     

An exact analytic method applied to nonhomogeneous ring- and stringer-stiffened cylindrical shells

In this paper, the nonlinear axial symmetric deformation problem of nonhomogeneous ring- and stringer-stiffened shells is first solved by the exact analytic method. An analytic expression of displacements and stress resultants is obtained and its convergence is proved. Displacements and stress resultants converge to exact solution uniformly. Finally, it is only necessary to solve a system of linear algebraic equations with two unknowns. Four numerical examples are given at the end of the paper which indicate that satisfactory results can be obtained by the exact analytic method.     

5-(2,3-二羟丙基)嘧啶的合成及其高碘酸盐氧化

近十年来,呋喃和嘧啶的并合体系之一的呋喃并[2,3-d]嘧啶的合成受到了一定的注意.对其衍生物的肌肉松弛、利尿、抗敏、镇静等作用及抗癌作用曾进行了研究.两个主要的合成途径是由取代4-羟基嘧啶与a-卤代羰基化合物缩合,或从2-氨基呋喃-3-甲腈或酮与胺或甲酰胺环化.     

宁波企业科技创新投入与产出关联度实证分析

运用灰色关联度测定理论,通过对宁波企业科技创新投入和产出指标的设定,运用实证分析法,计算宁波企业2001～2007年科技投入因素与产出指标之间的关联度及其综合排名.研究结果表明：技术改造投入、研究与发展人员投入、科技项目投入对产出指标影响最为显著,而技术引进、研究与发展经费的支出对产出指标影响最不显著.     

近红外漫反射光谱法测定川藏道地药材菥蓂子中黑芥子苷含量

提出了用近红外光谱技术快速测定川藏道地药材菥蓂子中指标成分黑芥子苷含量的方法。对黑芥子苷含量在1.962%～3.917%范围的不同来源的菥蓂子,根据其在12 500～3 600 cm-1的近红外吸收光谱,采用偏最小二乘法(PLS)建立了校正模型,比较了光谱不同预处理方法对校正结果的影响。当采用最大最小归一化法时能最有效地提取光谱的信息,此时校正集相关系数(r)为0.989 8,校正集标准偏差(SEC)为0.023 3, 预测集标准偏差(SPE)为0.111 2。该方法快速简便,适合于重要指标成分的快速分析。