混凝土刚构桥高大边跨不平衡现浇施工技术

以黄延高速公路葫芦河特大桥施工为背景，介绍边跨现浇施工中，通过及时改变合龙顺序，缩短边跨现浇段长度，在边跨采用不平衡悬浇与托架现浇相结合的方法，成功解决了边跨高墩跨大的施工难题，为以后工程施工提出有益的探索。     

锚杆支护在整治高地应力软岩隧道大变形的效应分析

根据乌鞘岭隧道工程实例阐述了高地应力软岩隧道大变形的特点，及其整治措施，通过模型计算对施作锚杆隧道与没有施作锚杆隧道的应力以及位移进行了比较，并论述了锚杆支护对于整治大变形的重要作用。     

Testing circular symmetry

The author addresses the problem of testing circular data for reflective symmetry about an unknown central direction and proposes a simple omnibus test based on the sample second sine moment about an estimation of this direction. Under quite general conditions, for an underlying distribution which is reflectively symmetric, the large‐sample asymptotic distribution of the test statistic is standard normal. Randomization and bootstrap variants of the test are also introduced, and the operating characteristics of different versions of the test are investigated in a Monte Carlo study. The large‐sample and bootstrap versions of the test are applied in the analysis of two illustrative examples drawn from the circular statistics literature.     

Saddlepoint approximations for some models of circular data

In this article we provide saddlepoint approximations for some important models of circular data. The particularity of these saddlepoint approximations is that they do not require solving the saddlepoint equation iteratively, so their evaluation is immediate. We first give very accurate approximations to P-values, critical values and power functions for some optimal tests regarding the concentration parameter under wrapped symmetric α-stable and circular normal models. Then, we consider an approximation to the distribution of a projection of the two-dimensional Pearson random walk with exponential step sizes.     

滚珠直旋副滚道弹性接触分析

滚珠直旋副是一种将直线运动转换为旋转运动的滚珠丝杠传动，其特点是具有较大的螺旋升角。本文就这类传动钢球与丝杠及螺母的弹性接触问题进行理论分析，建立弹性接触变形及额定负荷表达式，并就接触强度和接触刚度的有关影响因素进行了讨论。     

拒不说明巨额财产来源罪探讨

本文从维护廉政制度角度,提出“拒不说明巨额财产来源”侵害的是国家机关的正常活动和廉政制度双重客体;表现为行为人拒不履行保持公正廉洁的特定义务;其犯罪主体是国家工作人员:其主观方面是由故意构成。据上设“拒不说明巨额财产来源罪”成立。     

关于一集类圆柱投影的探讨

本文所要探讨的是一集类圆柱投影。它不同于伪圆柱投影,而属于标准线型投影族的一个新类型;其中包含着两个新型的等面积投影。     

Large sample interval estimation for the logarithmic series distribution

It is assumed that a large random sample of fixed size n is drawn from a logarithmic series distribution with parameter $tH and that it is desired to estimate e by means of two-sided confidence interval. Using asymptotic results, charts of confidence intervals are prepared for n = 50, 100, 200, 500 and 1,000, and confidence coefficients 0.90 and 0.95.     

穿层钻孔周围煤体次生应力变形及瓦斯流动规律的研究

从煤层钻孔周围煤体发生的次生应力和变形出发,建立了受煤体次生应力、瓦斯压力等因素影响的煤体变透气性系数的新数学模型,并以此改进了钻孔周围瓦斯流动的本构方程。通过对白皎煤矿20102试验区穿层钻孔周围瓦斯流场的解算,证明该模型和本构方程与实际相符,同时对常、变透气性也做了对比。     

Fixed‐Effects Dynamic Panel Models,a Factor Analytical Method

We consider the estimation of dynamic panel data models in the presence of incidental parameters in both dimensions: individual fixed‐effects and time fixed‐effects, as well as incidental parameters in the variances. We adopt the factor analytical approach by estimating the sample variance of individual effects rather than the effects themselves. In the presence of cross‐sectional heteroskedasticity, the factor method estimates the average of the cross‐sectional variances instead of the individual variances. The method thereby eliminates the incidental‐parameter problem in the means and in the variances over the cross‐sectional dimension. We further show that estimating the time effects and heteroskedasticities in the time dimension does not lead to the incidental‐parameter bias even when T and N are comparable. Moreover, efficient and robust estimation is obtained by jointly estimating heteroskedasticities.