我国工业企业研发现状及创新绩效研究

本文首先对我国工业企业研发投入现状、创新绩效水平进行分析,结果表明我国工业企业的研发状况和创新水平跟随整体经济的波动而变化,但并未体现出对整体经济的驱动作用。此外,技术获取的对外依赖性逐渐降低,但国内替代路径的发展不足导致依赖性减小的速度减缓。其次,本文对工业企业创新中最为重要的国有工业企业的创新现状进行了观察和分析,发现国有工业企业对我国基础性创新的贡献显著。最后,根据之前的研究结果提出相关的政策性建议。     

XYn型分子柔度通用线性关系式

根据分子柔度和规则，分别导出了ＸＹ＿３（Ｄ＿（３ｈ））、ＸＹ＿４（Ｄ＿（４ｈ））、ＸＹ＿４（Ｔ＿ｄ）、ＸＹ＿５（Ｄ＿（３ｈ））、ＸＹ＿５（Ｃ＿（４ｖ））和ＸＹ＿６（Ｏ＿ｈ）型分子柔度的通用线性关系式，并对关系式的正确性和用途作了讨论。     

多级神经元网络A／D转换及其级联实现

在对利用神经元网络实现Ａ／Ｄ转换的几种方法进行模拟分析的基础上，引入多级神经元的概念．采用下三角权连接结构，提出具有下三角权连接结构的多级神经元网络．对４ｂｉｔＡ／Ｄ转换进行了计算机模拟，效果良好．模拟结果表明，既有效地克服了迟滞现象，又减少了神经元和连接权的数量．在进行高比特转换时，采用级联实现可简化设计方法，便于推广和大规模集成应用．     

Vitamin D receptors in heart: Effects on atrial natiuretic factor

We report that receptors for vitamin D exist in distinct regions of the heart in female and male mice, predominantly in the right atrium where most of the cardial atrial natriuretic peptide (ANF) is produced. Tritiated 1,25-dihydroxyvitamin D₃ (1,25-D₃, vitamin D, soltriol) and ANF are colocalized in nuclei and cytoplasm respectively in identical cardiomyocytes. Changes of ANF tissue and blood levels under dietary deficiency and treatment with 1,25-D₃ suggest direct genomic actions of vitamin D on myoendocrine cells of the atrium for the regulation of ANF manufacture and secretion. These results were obtained by combining thaw-mount autoradiography with immunocytochemistry using tritiated 1,25-D₃ and an antibody against rat ANF. This antibody was also used in a radioimmunoassay to determine atrial natriuretic factor in plasma, atria and ventricles of normal or vitamin D-deficient mice.     

增强型51单片机可编程时钟输出功能及其应用

介绍了增强型5单1片机的可编程时钟输出功能及其实际应用，利用此功能设计了电路简单、精度高、性能稳定、抗干扰能力强、性价比高的4-20mA电流输出电路．     

单片机在分析化学中的应用

通过介绍由8051建立的单片机数据处理系统，将分析化学的电位滴定实验仪器与单片机系统结合起来，解决分析化学实验中的数据处理问题，并给出了有关硬件和软件设计。     

Gene conversion in the chicken immunoglobulin locus: A paradigm of homologous recombination in higher eukaryotes

Gene conversion was first defined in yeast as a type of homologous recombination in which the donor sequence does not change. In chicken B cells, gene conversion builds the antigen receptor repertoire by introducing sequence diversity into the immunoglobulin genes. Immunoglobulin gene conversion continues at high frequency in an avian leukosis virus induced chicken B cell line. This cell line can be modified by homologous integration of transfected DNA constructs offering a model system for studying gene conversion in higher eukaryotes. In search for genes which might participate in chicken immunoglobulin gene conversion, we have identified chicken counterparts of the yeastRAD51, RAD52, andRAD54 genes. Disruption and overexpression of these genes in the chicken B cell line may clarify their role in gene conversion and gene targeting.     

S.D.球化剂对铸态锰白口铸铁碳化物团球化作用的研究(一)

团球状碳化物是白口铸铁组织中较好的碳化物形态，而铸态团球化处理工艺是最简便的处理 工艺。本文讨论了一种新型球化剂──Ｓ．Ｄ．球化剂对低碳中锰白口铸铁碳化物团球化处理的作用。 通过对显微组织的观察以及通过Ｘ光衍射对基体奥氏体含量的测定表明，当Ｓ．Ｄ．球化剂加入量为 ４％时，碳化物团球化效果最好；而合金锰含量为８．５－９．５ ％即可获得单相的奥氏体基体组织。此 时，合金材料既抗磨又富有韧性，ａＫ值达６．６１ｋｇ－ｍ／ｃｍ２．     

用微型计算机计算平面共振分子的电子结构

本文是用BASIC语言编写的Hückel近似计算程序,在APPLEⅡ~+上获得通过.可用于计算无杂原子的平面共轭体系的轨道能量本征值,轨道波函数,电荷密度,键级,自由度等.可供量子化学和结构化学的实验教学参考.