Mice deficient for Rb are nonviable and show defects in neurogenesis and haematopoiesis.

The retinoblastoma gene, a prototypic tumour-suppressor gene, encodes a nuclear phosphoprotein (Rb). To understand better the role of Rb in development and in tumorigenesis, mice with an insertional mutation in exon 20 of the Rb-1 locus were generated. Homozygous mutants die before the 16th embryonic day with multiple defects. The haematopoietic system is abnormal; there is a significant increase in the number of immature nucleated erythrocytes. In the nervous system, ectopic mitoses and massive cell death are found, particularly in the hindbrain. All spinal ganglion cells die, but the neural retina is unaffected. Transfer of the human retinoblastoma (RB) mini-transgene into the mutant mice corrects the developmental defects. Thus, Rb is essential for normal mouse development.     

三维温度场中的多通道干涉层析

本文论述了非对称温度场的干涉层析法原理,提出了一种利用多路F-P干涉仪来进行三维温度场的多通道干涉层析的新方法,并用计算机模拟计算了各通道的最佳夹角。应用该方法测量了非轴对称双芯火焰,定量给出了其三维温度分布值。     

Heat Treatment of WC-Co Hardmetals and Transformation Temperature of Cobalt Phase

The Present work has found that the transverse rupture stren -gth of WC-Co hardmetals can be improved by queuching heat treatment. The increment of transverse rupture strength (4TRS) was dependent on the cobalt content of hardmetal. The higher the cobalt content of hardmetal is, the more the increment of transverse rupture strength is. The main reason is that the transformation of face centered cubic cobalt stabilized at high temperature to hexagonal close packed cobalt can be depressed by quenching. The transformation temperature of hexagonal close packed cobalt binder phase was determined by differential thermal analysis. It was found that the transformation temperature increases with increase of cobalt content of hardmetal. The reason is that the cobalt binder phase of high cobalt hardmetal contains higher tungsten content than that of low cobalt hardmetal after quenching.     

石墨/聚苯硫醚导电高聚物的结晶形态、微观多相结构和电导机制

在聚苯硫醚(PPS)中掺入不同浓度的石墨,经共混、研磨、压型,在熔点下制成G/PPS导电高聚物。电导率从10~(-16)S/m上升到2S/m作出了“σ-y”曲线。曲线和前人同类物质曲线有显著不同。以高分辨透射电镜,SEM,X射线,XPS,FTIR-PAS技术研究了G/PPS的结晶形态、电荷转移、电子结构变化以及C—S键合作用的现象。发现G/PPS导电高聚物中有六方晶体石墨、G/PPS分层取向层状结构、G/PPS分层卷折结构、G/PPS交错薄层结构等四种共存的微多相。用C—S键合增强、有序度涨落的观点,讨论了电导机制。为提高材料性能和开发应用提供重要的信息。     

非光滑系数的双曲型拟微分算子方程解的奇性传播

M.Beals(1982年)与M.Reed(1984年)相继研究了非光滑系数的拟微分算子方程解的奇性传播,并找到到了一般结果的应用。本文讨论另一类非光滑系数的拟微分算子方程解的奇性传播,在本文的结尾,我们给出了所得奇性传播定理的应用。     

二阶完全非线性椭圆方程古典解先验估计的注记

本文改进前文二阶完全非线性椭椭圆型方程古典解的一些先验估计的结果。该文中所有结论在条件Fs去除后仍成立。 [1]中讨论了如下问题 F(D~2u,Du,u,x)=0 在Ω;u=0在Ω(1)其中Ω为R~(n~2)中的有界区域。本文改进[1]的引理2.1,除去[1]中条件F_s的限制同样获     

非齐次双边生灭过程的积分型泛函

本文引进一类非齐次双边生灭过程模型,并讨论了它的积分型泛函.     

最优化与不等式

本文通过讨论三种类型的约束优化问题,利用Kuhn—Tucker条件导出著名的钟开莱不等式、算术一几何平均不等式, Cauchy—Schwarz不等式,HoIder不等式及其推广。     

计及转子阻尼效应的定子谐波漏抗

给出考虑转子谐波对定子谐波的阻尼作用时,鼠笼式异步电动机定子绕组谐波漏抗的计算方法.这一方法在参数计算准确度方面优于传统方法;同时对变极调速异步电动机,当其定子磁势谐波含量比正规绕组较大时,其电磁计算尤为重要。     

全液压汽车起重机伸缩臂专用绘图软件研制

本系统以通用绘图软件包ＡｕｔｏＣＡＤ为支撑软件，用ｐａｓｃａｌ语言编程，实现了变参绘图，以人机交互方式对数据进行修改和维护，建立友好人机界面，在单用户微机上完成伸缩臂图形的自动输出。