用Ω展开方法讨论化学体系的涨落

运用ＶａｎＫａｍｐｅｎ提出的Ω展开方法，对两个化学反应系统：进行了研究，建立了这两个反应系统组分浓度的一阶矩和二阶矩。     

绕水平圆柱层流自然对流数值模拟

从Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程和能量方程入手，利用有限差分方法摸拟绕水平圆柱定常层流自然对流流动，采用流函数涡量无量纲方程，非均匀网格剖分，二阶精度差分格式，非均匀圆柱表面温度分布，计算了瑞利数Ｒａ在１０４～１０６，普朗特数Ｐｒ在０．７～１００范围内的各种非均匀表面温度分布下的绕水平圆柱自然对流，特别是在圆往表面温度局部低于室温情况下，计算出了回流。全部结果与实际情况及已有的实验计算结果吻合。     

光弹性法和焦散线法研究联结零件接触应力

采用经典的三维光弹性实验技术和新兴的焦散线实验方法，分别研究了螺栓联结件的三维接触应力及其接触影响区域。所得实验结果为汽缸盖接触联结系统的设计、机械螺栓联结零件的有限元计算及其可靠性分析，提供了实验依据，并开拓了焦散线法实验的应用范围。     

大坝变形信息判据与分析

应用概率统计原理，对水库大坝变形观测中的变形值与随机因素干扰建立了变形数学模型。为排除干扰，提取真正变形信息，正确判据和分析大坝变形状态与规律提供理论依据。该数学模型在水库的实际应用中获得良好效果。     

求解k阶线性递归方程组的一种更有效的并行算法

将求解ｋ（ｋ≥２）阶线性递归方程组问题转化为求矩阵序列部分积问题，在ＳＩＭＤ共享存储模型上提出了求解ｋ阶线性递归方程组的一种新的有效并行算法．研究表明，本算法的加速和效率比现有算法均有较大的改善．     

使过半数规则具有传递性的偏好断面的规模

证明了当ｎ＞３时，使过半数投票表决的结果具有传递性的个人偏好序的最大数目大于２￣（ｎ－），从而否定了Ｃｒａｖｅｎ猜想。文中给出了最大偏好序的递推公式以及确定相应约束集的三条规则。     

Thymic selection process induced by hybrid antibodies

Thymus-derived (T) lymphocytes using the alpha beta T-cell antigen receptor (TCR) recognize fragmented antigen in conjunction with surface molecules encoded by genes of the major histocompatibility complex (MHC). Peripheral T lymphocytes preferentially see antigen presented by self rather than by foreign MHC molecules, and autoreactive T lymphocytes are deleted. Thus, the peripheral T-lymphocyte repertoire is skewed towards recognition of antigen in the context of self-MHC and towards tolerance to self-antigens. During T-lymphocyte development in the thymus, this repertoire is formed by the interaction of TCR with MHC molecules resulting in positive and negative selection phenomena. Hybrid antibodies (HAbs) that carry binding sites to the TCR and to a surface marker on another cell can engage all T lymphocytes regardless of their specificity. It should be possible to mimic selection processes in normal animals with HAb that specifically link members of a TCR family to MHC molecules on the thymic stroma. We have probed T-lymphocyte development with HAbs linking V beta 8-positive TCR to either class I or class II MHC products in thymic organ culture. Thymocytes exposed to either HAb in an early stage of maturation respond with a significant increase in the frequency of V beta 8-carrying cells. At a later stage of development V beta 8-positive thymocytes are depleted. These results illustrate the succession of positive and negative selection in the developing thymus of normal mice.     

Self-tolerance eliminates T cells specific for Mls-modified products of the major histocompatibility complex

In mice the product of the Mlsa locus is an unusual antigen capable of interaction with certain products of the major histocompatibility locus (MHC) to form a ligand for a large portion of the T-cell alpha/beta receptor repertoire, including nearly all receptors that use V beta 8.1. The presence of Mlsa/MHC during T-cell development results in the deletion of T cells that express V beta 8.1, documenting the importance of clonal deletion in establishing tolerance to self antigens.     

Analysis of the relationship between age of larvae at mutagen treatment and frequency and size of spots in the wing somatic mutation and recombination test inDrosophila melanogaster

The relationship between the induction of mutant clones and the time of mutagen treatment was studied in the somatic mutation and recombination test (SMART) in wing cells ofDrosophila melanogaster. Larvae trans-heterozygous for the recessive marker mutations multiple wing hairs (mwh) and flare (flr) were produced. Batches of these larvae were then treated with mutagen at different ages spanning all three larval instars. Methyl methanesulfonate was fed acutely for 2 h by immersing the larvae in a solution of the mutagen mixed with powdered cellulose. Wings of the surviving adult flies were mounted and scored for the presence of spots. The frequency and size of single and twin spots were recorded separately. Twin spots are produced exclusively by mitotic recombination, whereas single spots can results from various types of mutational and exchange events. There exists a clear correlation between time of induction and frequency as well as size of the single spots. In young larvae only few but very large spots are induced, whereas in older larvae the frequencies are considerably increased but the sizes are smaller. The twin spots show a different relationship. Practically no twin spots are found in very young and in very old larvae. The results demonstrate that in the wing spot test the optimal age of the larvae for mutagen treatment is 72 h.     

Active sliding between cytoplasmic microtubules

Microtubules are versatile cellular polymers that play a role in cell shape determination and mediate various motile processes such as ciliary and flagellar bending, chromosome movements and organelle transport. That a sliding microtubule mechanism can generate force has been demonstrated in highly ordered structures such as axonemes, and microtubule-based force generation almost certainly contributes to the function of mitotic and meiotic spindles. Most cytoplasmic microtubule arrays, however, do not exhibit the structural regularity of axonemes and some spindles, and often appear disorganized. Yet many cellular activities (such as shape changes during morphogenesis, axonal extension and spindle assembly) involve highly coordinated microtubule behaviour and possibly require force generated by an intermicrotubule sliding mechanism, or perhaps use sliding to move microtubules rapidly into a protrusion for stabilization. Here we show that active sliding between cytoplasmic microtubules can occur in microtubule bundles of the amoeba Reticulomyxa. A force-producing mechanism of this sort could be used by this organism to facilitate the extension of cell processes and to generate the dynamic movements of the cytoplasmic network.