时间序列AR模型参数的积分求解法

基于对时间序列实质的分析，提出了旨在减少序列的随机误差影响以及提高拟合精度的ＡＲ模型参数的积分求解法．重点讨论了ＡＲ（１）模型及ＡＲ（ｐ）模型参数的积分求解法，并与最小二乘法在计算机上进行了仿真比较．结果表明，采用积分求解法所得的ＡＲ模型参数的估计精度比最小二乘法的高．     

二值点阵图像的放大与缩小方法研究

着重研究了二值点阵图像的放大、缩小方法，针对二值点阵灰度图和工程图现有的缩小和放大算法及存在的问题，提出了基于区域特征的图像变换思想，以图块为单位进行图像的放大、缩小．据此，提出了对二值灰度图和工程图进行放大、缩小的改进算法并进行分析。     

损伤材料中扩展裂纹的应力场

利用Ｇｕｒｓｏｎ本构理论，导出了损伤材料在平面应力条件下准静态定常扩展Ｉ型裂纹近裂纹线应力场和裂纹前方塑性区尺寸的解析表达式。研究结果表明：随着材料损伤量的增加，裂纹尖端处应力降低；裂纹尖端处应力不存在奇异性；裂纹前方塑性区尺寸受材料损伤程度的影响。     

三维各向异性非线性位场边值问题的多媒质有限元分析

基于变分有限元法，建立了各向异性非线性媒质中三维位场边值问题多媒质单元有限元分析的标量和矢量位分析模型，推导了单元分析的实用分析格式。讨论结合两种典型的八节点六面体多媒质等参单元进行，所得分析结果已成功应用于电力变压器铁芯磁场的三维分析与计算。     

单角煤粉燃烧炉中煤粉着火与稳燃的数学模型

将煤粉空气两相流在着火前和着火期间基本上仍遵从的射流发展规律作为模型基础，考虑了煤粉颗粒与气相间的速度滑移与温度滑移。气相场按射流规律发展井计及颗粒群对气相温度、速度、浓度变化的影响；颗粒群则按Ｌａｇｒａｎｇｅ处理方法追踪颗粒变化史。模型首次采用了挥发分与环境氧气匹配达着火限方能产生挥发分火焰的概念并取得了与实验现象一致的计算结果。     

煤中痕量元素分布特征的聚类分析研究

测定了青山烟煤、合山烟煤、莱阳无烟煤、加福无烟煤、河南贫煤、黄石贫煤和韶关贫煤等七种不同煤样中的Ａｓ，Ｃｒ，Ｃｏ，Ｐｂ，Ｎｉ，Ｖ，Ｃｕ，Ｃｄ，Ｂｅ，Ｇｅ等１０种痕量元素的含量，并用聚类分析法分别对１０种痕量元素和七种煤样进行分类研究，解释了这些痕量元素在煤中的分布特征。     

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。     

Presynaptic release probability influences the locus of long-term potentiation.

The quantal hypothesis proposes that chemical synaptic transmission involves the probabilistic release of multimolecular packets of transmitter. Analysis of the resulting trial-to-trial fluctuations in postsynaptic response can provide estimates both of the number of quanta released and of the size of their postsynaptic effect. This in turn permits the quantification of the relative contributions of pre- and postsynaptic factors to the strength of a given synapse. Quantal analysis of excitatory synapses in the hippocampus has proved difficult and has led to contradictory conclusions when applied to long-term potentiation. Here we report the use of a combination of quantal analysis procedures to provide evidence that both pre- and postsynaptic changes can contribute substantially to the maintenance of long-term potentiation in the CA1 region of the hippocampus. The initial setting of the presynaptic release mechanism seems to determine their relative importance.     

Probing met repressor-operator recognition in solution.

The three-dimensional crystal structure of the Escherichia coli methionine repressor, MetJ, complexed with a DNA operator fragment is described in an accompanying article. The complex exhibits several novel features of DNA-protein interaction. DNA sequence recognition is achieved largely by hydrogen-bond contacts between the bases and amino-acid side chains located on a beta-ribbon, a mode of recognition previously hypothesized on the basis of modelling of idealized beta-strands and DNA, and mutagenesis of the Salmonella phage P22 repressors Arc and Mnt. The complex comprises a pair of MetJ repressor dimers which bind to adjacent met-box sites on the DNA, and contact each other by means of a pair of antiparallel alpha-helices. Here we assess the importance of these contacts, and also of contacts that would be made between the C-helices of the protein and DNA in a previous model of the complex, by studying mutations aimed at disrupting them. The role of the carboxy-terminal helix face in operator binding was unclear, but we demonstrate that recognition of operator sequences occurs through side chains in the beta-strand motif and that dimer-dimer interactions are required for effective repression.