多维超几何分布的最可能成功数

超几何分布是一种重要的离散型概率分布,本文利用反证法以及比较法求出了三维超几何分布的最可能成功次数,并在此基础上,求出了多维超几何分布的最可能成功次数.     

高素质人才加入公务员队伍的制约因素和对策研究

治国重在治吏,善治来于"善吏",政府的社会作用是通过全体公务员的有效工作体现出来。随着我国公务员制度的逐步完善,公务员的素质已有所提高,但高素质人才占公务员总体的比例仍然不高,这与我国的人才外流、公务员制度运行及人才服务体系不健全等现象也有一定关系。本文通过对我国公务员队伍现状的分析,指出了阻碍高素质人才加入公务员队伍的原因,并相应地提出了吸引和激励更多高素质的人才加入到公务员队伍对策。     

Application of structural curvature of coalbed floor on CBM development in the Zaoyuan block of the southern Qinshui Basin

Based on controls of structural style and the position in coalbed methane(CBM)development,we used a method of curvatures to study its relations with CBM development parameters.We calculated structural curvatures of contours of the No.3coal seam floor of the Shanxi Formation in the Zaoyuan block of the Qinshui Basin and analyzed its relations with development parameters of coalbed methane wells.The results show that structural curvature is negatively related to coal reservoir pressure,while positively related to permeability.With an increase in structural curvature,the average production of coalbed methane wells increases at first and then decreases,reaching the highest production at 0.02 m-1 of structural curvature.Therefore,structural curvature can be an important index for potential evaluation of coalbed methane development and provide a basis for siting coalbed methane wells.     

Monitoring slope deformation using a 3-D laser image scanning system:a case study

An ILRIS-36D 3-D laser image scanning system was used to monitor the Anjialing strip mine slope on Pingshuo in Shanxi province.The basic working principles,performance indexes,features and data collection and processing methods are illustrated.The point cloud results are analyzed in detail.The rescale range analysis method was used to analyze the deformation characteristics of the slope.The results show that the trend of slope displacement is stable and that the degree of landslide danger is low.This work indicates that 3-D laser image scanning can supply multi-parameter,high precision real time data over long distances.These data can be used to study the distortion of the slope quickly and accurately.     

有限导流垂直裂缝产能及影响因素研究

从渗流理论出发,利用瞬时源、连续源的思想,结合卷积公式、Laphce变换等方法,建立了有限导流垂直裂缝井的产能计算模型,对模型导出的积分方程采用边界元方法(BEM)在Laplace空间进行了求解,利用Stehfest数值反演.获得了实空间的解,从而给出了准确计算有限导流垂直裂缝井产量的方法.此外,还通过定量计算分析了裂缝各设计参数对产量的影响方式和影响程度.通过分析可知,压裂井的日产量随裂缝长度、裂缝渗透率、裂缝宽度的增加而增大,但其产量增加的幅度随三种因素的增大而逐渐减小,因此在实际的油藏水力压裂设计时,应结合压裂成本和增益来考虑合适的设计参数.对压裂井产量预测和水力压裂油藏工程设计具有一定价值.     

适度出砂技术在海上稠油油田的应用研究

通过理论计算和室内出砂模拟实验,分别从地层出砂、井筒附近防砂以及井筒内的携砂生产三方面时适度出砂开采方式进行了研究.结果表明:地层出砂对储层物性有所改善,不同粒径段颗粒出砂1%后,渗透率增幅为20%左右,其中细微砂粒(<39 μm)的产出对渗透率提高贡献最大,为21,07%-37.60%;防砂管和地层环空间砂粒的堆积对产能影响很大,环空无砂时产能提高1.71倍,但当环空充满砂时产能仅提高14.70%;只有当井筒内的流体流速大于等于砂粒的沉降末速时产出砂才能被携带出井筒.该开采方式在渤海稠油油田得到成功应用.     

Relationship of hydrocarbon and source-rock in Nos.3-5 tectonic belts of the Lenghu area, northern Qaidam Basin

Based on analyses of the components of crude oil hydrocarbons and carbon isotopes, the content of normal alkane de-creased from 49.00% to 20.10% when moving from the No.3 to No.5 tectonic belt of the Lenghu area of the Qaidam Basin, while cycloalkanes increased from 30.00% to 52.20% and aromatic and branch chain alkanes increased gradually as well. The maturity of sterane in crude oil is higher than that of its source-rock, which shows that the hydrocarbons were generated from a deep source-rock of high maturity around the tectonic belts of the Lenghu area. The analysis of the characteristics of carbon isotopes also shows that these isotopes of hydrocarbon compounds in the No.4 and No.5 tectonic belt are apparently heavier than those in the No.3 belt. The results of our research show that the hydrocarbons in the No.3 tectonic belt are mainly from a relatively rich sapropelic substance, while the hydrocarbons in the No.4 and No.5 tectonic belt originated mainly from organic matter of a rela-tively rich humic type substance.     

铒离子注入晶体硅的射程分布和离散研究

用400 keV能量的铒离子垂直注入晶体硅(Si)样品中。利用卢瑟福背散射技术研究了能量为400 keV、剂量为5×1015ions/cm2的铒离子注入Si晶体的平均投影射程、射程离散和深度分布。测出的实验值和TRIM 98得到的理论模拟值进行了比较,发现实验值跟TRIM 98模拟计算的理论值符合较好。     

大学教学与科研关系的探讨

大学职能的发展历经了从教学主导到教学科研并举的演变。教学与科研在大学的发展历程和具体运作过程中存在着不可避免的矛盾。二者结合是优化资源配置、发展创新教育的最佳途径,对大学进行有效的分层定位是协调二者关系的关键。具体包括在宏观战略上明确定位,同时加强组织重构、分类管理等。此外,大学文化之于教学与科研和谐也十分重要。     

电容器引线焊接机冲压切边凸轮的三维精确造型

根据电容器引线焊接机冲压切边模具中的凸轮设计要求,利用Pro/ENGINEER软件找出凸轮随动件滚子中心的轨迹,通过可变截面扫描间接得到凸轮的三维精确模型。为类似零件的建模提供一种行之有效的方法,并为后续的仿真分析和制造加工提供一种依据。