Relationships between changes of kernel nutritive components and seed vigor during development stages of F1 seeds of sh 2 sweet corn

The changes of kernel nutritive components and seed vigor in F₁ seeds of sh ₂ sweet corn during seed development stage were investigated and the relationships between them were analyzed by time series regression (TSR) analysis. The results show that total soluble sugar and reducing sugar contents gradually declined, while starch and soluble protein contents increased throughout the seed development stages. Germination percentage, energy of germination, germination index and vigor index gradually increased along with seed development and reached the highest levels at 38 d after pollination (DAP). The TSR showed that, during 14 to 42 DAP, total soluble sugar content was independent of the vigor parameters determined in present experiment, while the reducing sugar content had a significant effect on seed vigor. TSR equations between seed reducing sugar and seed vigor were also developed. There were negative correlations between the seed reducing sugar content and the germination percentage, energy of germination, germination index and vigor index, respectively. It is suggested that the seed germination, energy of germination, germination index and vigor index could be predicted by the content of reducing sugar in sweet corn seeds during seed development stages. Project supported by the National Natural Science Foundation of China (No. 30370911) and Education Department of Zhejiang Province, China (No. 20070147)     

非线性波动方程的双曲函数级数解法

采用双曲函数的幂级数表示一类非线性波动方程的特定显示行波解，根据领头项分析，这种函数级数解可以被截面为只有几项的形式－截为解，由此进一步得到它的扭状孤状波解、钟状孤波解，从而物理学上许多著名方程都可作为该方程的特殊情形而得到相应的二组孤波解。     

浅谈模拟电子技术课程中"反馈"判别方法的教学

本文对模拟电子技术课程中有关“反馈”的判别方法，诸如正、负反馈，电压、电流反馈以及串联、并联反馈等做了详细的分析比较．     

用实验室常规仪表提高RLC串联谐振中Q值测量精度的方法

本文介绍了用常规仪表提高RLC串联谐振中Q值测量精度的方法,并对教学实验室中的电阻箱、空心电感线圈、电容箱、常规仪表等器材对测量精度的影响作了分析,并用实验数据加以说明。     

Numerical Simulation of the Flat Ribbon Wound Explosion Containment Vessels Subjected to Internal Blast Loading

In order to constitute engineering design methods of the flat ribbon wound explosion containment vessels, the dynamic response of such vessels subjected to internal explosion loading is simulated using LS-DYNA3D. Three winding angles, 10°, 15°and 20°, are considered. It is shown that among ribbon vessels investigated, the center displacement of outermost ribbons of the vessel with 10°winding angle is the smallest under the same blast loading. The response of vessels loaded in inner core is local. From the center of the cylindrical shell to the bottom cover, the maximum strain gradually decreases. The ribbons are subjected to tension in the length direction and compression in the width direction. Blasting shock energy concentrates on where is close to center section of blasting. For comparison, numerical simulation of a monobloc thick-walled explosion containment vessel is also investigated. It can be found that the biggest deformation of the flat ribbon wound explosion containment vessels is bigger than that of the monobloc thick-walled explosion containment vessel in the center section of blasting under the same TNT. Numerical results are approximately in agreement with experimental ones. It is proved that the ribbon vessels have the valuable properties of " leak before burst at worst" compared with the monobloc vessels through numerical simulation.     

关于正整数的六边形数部分

对任意正数n,设b(n)表示n的最大六边形数部分,即就是b(n)=m(2m-1),如果m(2m-1)≤n<(m+1)(2m+1),m∈N.主要目的是研究由b(n)组成的一类Dirichlet级数的收敛性,并对一些特殊的情况给出一个有趣的计算公式.     

傅里叶系数公式推导的一个注记

指出现行教材中推导傅里叶系数会式的三种方法，并对每种方法进行点评，在此基础上，从逼近论的角度出发。应用多元函数极值的相关知识，提出了傅里叶系数公式的另一种推导方法，克服了现行分析教材在处理这个问题上的不足、缺陷。     

函数项级数一致收敛定义的推广及其应用

利用数列对用定义判别函数项级数一致收敛的方法进行推广，找到函数项级数一致收敛的充分条件和充要条件，提供了证明函数项级数一致收敛的一般方法。     

p维向量型随机Dirichlet级数的增长性

通过引入辅助级数∑n=1^∞Une-Eλn^n，分别研究了P维向量型随机Dirichlet级数在收敛平面和收敛半平面上的增长性，证明了p维向量型随机Dirichlet级数和辅助级数在一定条件下增长级a．s．相等．     

非线性代数方程的数值计算及收敛速度分析

用计算机对非线性代数方程给出不同的数值计算方法,并讨论其收敛速度。