挤扩多盘桩土体极限承载力影响因素的研究

根据挤扩多盘桩桩土效应及土体极限承载力的理论分析和试验研究的成果,对挤扩多盘桩土体极限承载力的多种影响因素进行了定性或定量的分析,为进一步综合考虑各项因素进行挤扩多盘桩基础设计,提供了理论依据。     

静压敞口钢管桩在某仓库改建中的应用

以上海某仓库楼电梯间的基础设计和施工为例，着重介绍了在场地狭小、大型施工机械无法进场、紧邻周边建筑物的情况下，采用静压敞口钢管桩成功穿越饱和黏土层的方法．工程达到预定设计要求，为类似工程的设计和施工提供了参考．     

锌锰干电池的一种代汞缓蚀剂

通过实验，筛选出一种新型缓蚀剂，这种缓蚀剂用于锌锰干电池中.完全可以代替汞（盐）。将这种缓蚀剂加入浆糊层中代替汞（盐），并制作了R20S电池，通过测量电池各项电性能，均达到或超过GB7112-86国家标准.贮存一年后放电容量保持新电池的94％。     

喷气涡流纺喷孔数量对喷嘴内气流场的影响

为了研究喷孔数量对喷嘴内气流场的影响,应用FLUENT流体计算软件对喷嘴内部气流场进行数值模拟,并结合OriginPro对不同喷孔数量时喷嘴内部气流场状况进行比较和分析,深入解析喷孔数量对涡流场的影响。研究表明：喷孔数量对喷嘴内部气流场的特性影响较为明显,随着喷孔数量的增多,气流在喷嘴中形成的旋转运动增强,喷嘴入口处用以吸引纤维的负压也随之增大,对纱线的加捻特性也就越强。     

水力喷射压裂孔内压力分布研究

水力喷射压裂工艺是集水力射孔和压裂一体的新型油田增产技术。在室内实验基础上， 运用流体力学计算方法， 对水力喷射压裂孔道内压力场进行计算， 得到了井下水力射流在地层孔道内的压力及速度分布， 揭示了喷嘴空间位置、 喷嘴数量、 孔道形状、 喷嘴压降和喷嘴直径对孔道压力的影响规律。结果表明：高速射流之间具有很强的独立性， 喷嘴空间位置和喷嘴数量不会影响孔道内压力； 水力射流在不同形状孔道内产生的压力相同； 孔道压力随喷嘴压降和喷嘴直径的增大而增加。     

Modified maximum likelihood estimator for the mixing distribution in a finite mixture

Using the likelihood equations, a method based on the generalized inverse of matrices is proposed to derive closed-form estimates for the mixing proportions in a finite mixture, when the component distributions are known.     

粉煤灰对高强混凝土性能的影响

在泵送混凝土中掺入适量的粉煤灰,特别是与减水剂复合使用时,不仅经济效益显著,而且能改善混凝土的性能.研究了粉煤灰高强混凝土中粉煤灰的细度、掺量对混凝土流动性、可泵性及强度的影响,最后给出了煤灰在高强混凝土中的最优掺量,可为工程应用借鉴.     

Semiparametric Mixtures of Generalized Exponential Families

Abstract.  A semiparametric mixture model is characterized by a non-parametric mixing distribution Q (with respect to a parameter θ ) and a structural parameter β common to all components. Much of the literature on mixture models has focused on fixing β and estimating Q . However, this can lead to inconsistent estimation of both Q and the order of the model m . Creating a framework for consistent estimation remains an open problem and is the focus of this article. We formulate a class of generalized exponential family (GEF) models and establish sufficient conditions for the identifiability of finite mixtures formed from a GEF along with sufficient conditions for a nesting structure. Finite identifiability and nesting structure lead to the central result that semiparametric maximum likelihood estimation of Q and β fails. However, consistent estimation is possible if we restrict the class of mixing distributions and employ an information-theoretic approach. This article provides a foundation for inference in semiparametric mixture models, in which GEFs and their structural properties play an instrumental role.     

Asymptotic results for model robust regression

Since the mid 1980's many statisticians have studied methods for combining parametric and nonparametric models to improve the quality of fits in a regression problem. Notably Einsporn (1987) proposed the Model Robust Regression 1 estimate (MRRl) in which the parametric function, f, and the nonparametric functiong were combined in a straightforward fashion via the use of a mixing parameter, λ This technique was studied extensively atsmall samples and was shown to be quite effective at modeling various unusual functions. In this paper we have asymptotic results for the MRRl estimate in the case where λ is theoretically optimal, is asymptotically optimal and data driven, and is chosen with the PRESS statistic (Allen, 1971) We demonstrate that the MRRl estimate with λchosen by the PRESS statistic is slightly inferior asymptotically to the other two estimates, but, nevertheless possesses positive asymptotic qualities.     

高压水射流与机械联合作用处理堵塞油管

在油田开发过程水泥浆堵塞油管现象时有发生。传统的处理方法是将这些堵塞的油管报废,结果造成很大的浪费。在系统研究高压水射流流动规律和动力特性基础上,深入分析了水力与机械联合破岩机理,根据不同使用条件和适用对象,对水射流参数进行了调整,对钻头切削齿和喷嘴布置进行合理的设计。首创了一种高压水射流处理水泥堵塞油管新技术,设计制造了清洗堵塞油管专用设备和工具,现场实验取得了突破性进展。