二半山常规籼稻区种植早熟杂交稻初探

为加速我县二半山水稻品种的更新换代,种子站近年来积极引进适合我县二半山常规籼稻区新品种,但由于在新的市场机制下,可供引进的常规水稻新品种越来越少,即使筛选出一个新品种,在生产中的使用年限也只3～5年,品种更新速度已成为生产中最突出的问题,针对我县海拔1450-1700m二半山区水稻品种更新换代,种子站于2003年引进早熟杂交稻试验成功,改变了我县高二半山区不能种植杂交稻的历史。2004年示范20余亩,平均亩产达到了469.7公斤,较对照增长13.7％。     

基于CPLD半整数分频器的设计

本设计是应用CPLD器件的特点和应用范围,利用VHDL硬件描述语言以及原理图的输入方式设计出占空比可调的半整数分频器,从而满足根据更改N值来实现不同分频系数分频器的设计要求。     

Singularities Analysis of Paradoxical Mechanism and Parallel Manipulators

Parallel manipulator is associated with a set of functions defined by its closure constraints. In this paper, using Lie algebra method, we provide a study on the singularities of parallel manipulators, their relations with the second order of the closure functions, and the tangent space of the configuration space of the manipulator. The transverse condition criterion is applied to analyze the behavior of the singularities. This gives a downright explication why the 6R paradoxical mechanisms work in their singular configurations, and allows to gain insight on configuration space singularities and to choose the adequate design parameters for the parallel manipulator.     

N（2，2，0）代数的一类同余分解

对N(2,2,0)代数给出了一类同余分解,探讨了其商代数的代数结构以及自然同态下一类逆象的代数结构.     

Genetic analysis and molecular mapping of a presenescing leaf gene psll in rice （Oryza sativa L.）

A rice psl1 （presenescing leaf） mutant was obtained from a japonica variety Zhonghua 11 via radiation of ^60Co-γ in M2 generation. Every leaf of the mutant began to wither after it reached the biggest length, while the leaves of the wild variety could keep green for 25--35 d. In this study, genetic analysis and gene mapping were carried out for the mutant identified. The SSR marker analysis showed that the mutant was controlled by a single recessive gene （psl1） located on chromosome 2. Fine mapping of the psl1 locus was conducted with 34 new STS markers developed around psl1 anchored region based on the sequence diversity between Nipponbare and 93-11. The psl1 was further mapped between two STS markers, STS2-19 and STS2-26, with genetic distances of 0.43 and 0.11 cM, respectively, while cosegregated with STS2-25. A BAC contig was found to span the psl1 locus, the region being delimited to 48 kb. This result was very useful for cloning of the psl1 gene.     

(L)ukasiewicz命题逻辑系统中的赋值决定公式问题

为了在经典逻辑学中建立Fuzzy分离规则的推理模式，Zadeh提出了赋值决定公式问题（VDF问题），并已于二值命题逻辑以及Lukasiewicz三值和p＋1值命题逻辑中得到解决．文中在更一般的Lukasiewicz命题逻辑系统中建立了VDF问题的求解理论，首先给出了一般的Lukasiewicz命题逻辑系统中VDF的合理性条件，其次构造性地解决了Ln、La和Lc中的VDF问题．     

关于量子力学中效应代数上的收敛理论及不变量

本文介绍了量子力学中效应代数的研究进展。指出利用无穷矩阵理论研究其上的收敛理论和不变量，对建立量子力学的数学基础有重要意义。     

单一与混合体系的透明有机材料的性能比较

介绍了由甲苯二异氰酸酯(TDI)与各类二醇反应制备透明有机材料的过程。比较了单一大链与混合大链制备的透明有机材料的性能，指出混合大链制备的透明有机材料具有良好的机械性能和光性能以及良好的热挠曲温度。     

点集拓扑的40个问题

给出了点集拓扑40个问题,是点集拓扑问题的一部分.     

铁路机务段信息化建设刍议

文章对当前铁路机务段信息化建设现状进行了分析，对机务段信息化建设提出了建议，并对机务段信息系统主要内容进行了简要描述。