井眼倾斜角和倾斜方位对裸眼完井地层出砂的影响

结合等效塑性应变准则定量地研究了井眼倾斜角和倾斜方位对裸眼完井砂岩油藏出砂的影响。计算结果表明,在一定的应力和地层条件下,井斜角在0~45°时,随着井斜角的增加,井壁内的塑性应变最大值和塑性区范围都不断增加,出砂的趋势增大;当井斜角在45°~90°时,随着井斜角的增加,井眼内最大塑性应变逐渐减小,出砂趋势减小。井斜角相同,但井眼倾斜方位不同的井,井壁内产生塑性变形的区域不同,塑性变形的程度也不同,从防砂的角度,井眼,尤其水平井眼应该沿原地最小水平主应力方向,或尽可能靠近最小主应力方向。     

欧洲主权债务危机与欧元的前景

由美国次贷危机引发的全球性金融危机对欧洲大陆的冲击使欧洲长期积累的财政和债务问题逐步转变为主权债务危机。欧债危机的持续发酵主要是由欧元区内货币政策与财政政策脱节、高社会福利与低经济增长矛盾以及危机爆发后救助迟缓、乏力等因素导致的,同时它也是欧元区在建立之初就一直存在的严重的结构性缺陷所带来危害的集中体现。欧债危机对欧元区的稳定造成了极大冲击,给欧元未来的命运蒙上了一层阴影。欧元区未来的结局可能是促使欧债危机国家退出欧元区,而这对欧洲一体化进程则是沉重的打击。     

Computing optimal adjustment schemes for the general tool-wear problem

An important problem in process adjustment using feedback is how often to sample the process and when and by how much to apply an adjustment. Minimum cost feedback schemes based on simple, but practically interesting, models for disturbances and dynamics have been discussed in several particular cases. The more general situation in which there may be measurement and adjustment errors, deterministic process drift, and costs of taking an observation, of making an adjustment, and of being off target, is considered in this article. Assuming all these costs to be known, a numerical method to minimize the overall expected cost is presented. This numerical method provides the optimal sampling interval, action limits, and amount of adjustment; and the resulting average adjustment interval, mean squared deviation from target, and minimum overall expected cost. When the costs of taking an observation, of making an adjustment, and of being off target are not known, the method can be used to choose a particular scheme by judging the advantages and disadvantages of alternative options considering the mean squared deviation they produce, the frequency with which they require observations to be made, and the resulting overall length of time between adjustments. Computer codes that perform the required computations are provided in the appendices and applied to find optimal adjustment schemes in three real examples of application.     

The mad estimator: when is it non-linear? applications to two-way design models

The mean absolute deviation (MAD) estimator has recently received a great deal of attention as applied to full-rank linear regression models. This paper provides a necessary and sufficient condition for the MAD estimator to be a non-linear estimator, in which case conditions for the variance of the MAD estimator to be larger or smaller than those for OLS are, in general, unknown. The non-linearity of the MAD estimator is examined for several two-way designs; in particular (1) randomized block design (2) two-way nested design (3) two-way classification with interaction and (4) partially balanced incomplete block design     

社会认知偏差:群体性事件生成的社会心理启动根源

社会认知偏差是群体性事件生成的深层次社会心理现象,通过对山东部分地区进行抽样调查,并结合近几年来全国群体性事件典型案例的分析发现,生成群体性事件的社会认知偏差,主要包括事件诱因责任归因偏差、行为模式结果预期偏差和行为结果价值偏差。因此,改善法的实施现状,消除社会认知偏差;提高公众法律意识,优化社会认知;建立心理危机干预队伍,合理引导社会认知,是群体性事件社会认知偏差的有效干预对策。     

一种适用于空心电子束的慢波系统的理论

提出了一种新型同轴慢波系统——紧密缠绕螺旋线介质棒加载盘荷波导,解析推导了其色散方程和耦合阻抗的表达式,并给出了数值计算结果。结果表明:新型导波结构作为行波管的慢波系统,不但可使行波管具有相对较宽的频带,又可使其具有较高的耦合阻抗。     

电潜泵举升系统温度压力耦合计算方法研究

电潜泵温度场的准确计算对于设备的选型和正常生产意义重大。针对前人的方法往往没有考虑到压力对温度分布的耦合作用或仅仅假设生产系统中为单相流体的实际，建立了电潜泵举升系统     

城市旅游经济与生态环境系统耦合协调度比较研究——以上海、西安为例

基于协同论、可持续发展理论,在构建概念模型和数学模型的基础上,运用上海市和西安市2001-2009年的统计数据,对不同类型城市旅游经济与生态环境的耦合关系及协调发展演变过程做对比研究,结果发现：（1）城市旅游经济和生态环境系统之间普遍存在着相互影响、相互制约的耦合互动关系;（2）旅游经济与生态环境的相互作用与反馈是决定二者耦合关系的直接原因,而城市产业结构、旅游资源、市场客源、城市化进程、地理位置、气候环境方面的差异则是形成耦合关系的深层次基础;（3）耦合协调度评价模型能有效判断城市旅游经济与生态环境耦合关系与协调发展的状态,是研究旅游可持续发展的重要工具。     

Flexible regression modeling

The author proposes a new method for flexible regression modeling of multi‐dimensional data, where the regression function is approximated by a linear combination of logistic basis functions. The method is adaptive, selecting simple or more complex models as appropriate. The number, location, and (to some extent) shape of the basis functions are automatically determined from the data. The method is also affine invariant, so accuracy of the fit is not affected by rotation or scaling of the covariates. Squared error and absolute error criteria are both available for estimation. The latter provides a robust estimator of the conditional median function. Computation is relatively fast, particularly for large data sets, so the method is well suited for data mining applications.     

论元散曲中屈原评价的文化意义

元人对屈原基本上都是持一种嘲讽的态度。这种价值评判的形成 ,与元人的生存环境有着非常直接的关系。价值向度的变形来自于生存环境的险恶。同时 ,与历史上对屈原的消极评价也不无关联