兰州市污水管网工程中顶管施工技术应用与探讨

结合兰州市污水处理厂14#路段污水管网工程,对黄土地质条件下顶管推力进行了计算,并进一步从施工方案选择、施工工艺、流程以及顶管施工减阻、纠偏和测量控制等方面对顶管施工技术进行了较全面的论述.所述施工技术方案适用于兰州地区工程地质属于卵石层、透水性强、地下水丰富、地下水和河床水互补的实际情况,可供今后同类型工程参考.     

元素的Z^＊/r对元素的原子、离子及单质性质的影响

系统探讨了元素的Z^＊/r对元素的原子性质、离子性质、单质性质的广泛影响。     

Neuroreplacement therapy and stem cell biology under disease conditions

Recent advances in stem cell technology are expanding our ability to replace a variety of cells throughout the body. In the past, neurological diseases caused by the degeneration of neuronal cells were considered incurable because of a long-held 'truism'; neurons do not regenerate during adulthood. However, this statement has been challenged, and we have now found much evidence that the brain is indeed capable of regenerating neurons after maturing. Based on this new concept, researchers have shown neural differentiation of stem cells and recovery of function following transplantation of these cells into the brain. These results may promise a bright future for clinical applications of stem cell strategies in neurological diseases; however, we must consider the pathophysiological environments of individual diseases that may affect stem cell biology. Before we begin to develop clinical applications, we must consider environmental factors that have not been discussed in the current preclinical studies. Here, we study cases of Alzheimer's disease and schizophrenia and discuss the effects of environmental factors under disease conditions.Received 15 January 2003; received after revision 7 April 2003; accepted 8 April 2003     

(k+1)-连通无K_(1,r)-图是Hamilton-连通的两个充分条件

一个图若不含与Ｋ１,ｒ（ｒ３）同构的导出子图,则称它为无Ｋ１,ｒ－图．本文将运用Ｔ－插点方法,通过对图的独立集的邻域交的研究,给出（ｋ＋１）－连通无Ｋ１,ｒ－图（ｒ４）是Ｈａｍｉｌｔｏｎ－连通的两个充分条件．     

Jacobi Inversion Problem for the Modified Jaulent-Miodek Hierarchy

IntroductionTheseparabilityoftheHamilton-Jacobiequa-tionandtheclassicalPoissonstructureforafinite-dimensionalintegrableHamiltoniansystem(FDIHS)playsanimportantroleinconstructingsolutionsandintheunderstandingofthecompleteintegrabilityofanFDIHS[1,2].Recently,muchin-teresthasdevelopedinthestudyofseparationofvariablesforcompletelyintegrableHamiltoniansystems[3-12].ForsomeFDIHSs,theLaxmatrixandr-matrixprovideaneffectivewaytoinvestigatetheseparationofvariables.Ithasbeenshownthateachequation…     

关于Ramsey数r(3,q)下界公式的一点注记

本文证明了一类特殊的循环图是（3,q）—图,从而得到当q≥9且q是奇数时,r（3,q）≥8（q—8） 2     

Substance P-induced fibrinolysis in the forearm of healthy humans

Physiological saline with or without substance P (50 ng/ml) was infused into the humeral artery in 6 healthy males. Indices of fibrinolytic activity (whole blood diluted lysis time, euglobulin lysis time, lysis areas in non-heated fibrin plates produced by plasma or euglobulin precipitate, plasminogen plasma levels, ₂-macroglobulin, Cl-inhibitor, and ₂-antiplasmin) were evaluated in the homolateral antecubital vein before and after 5 min of substance P or saline infusion. After substance P the fibrinolytic activity increased, as can be seen from the shortening of lysis times (p<0.01) and enlargement of the lysis areas (p<0.01). A reduction of plasminogen plasma levels (p<0.01), associated with a decrease in ₂-anitplasmin (p<0.01), was also found. Alpha₂-macroglobulin and Cl-inhibitor were instead unaltered by the peptide. The saline infusion, on the other hand, was unable to modify any of the examined indices. We concluded that exogenous substance P given intra-arterially increases fibrinolytic activity in locally-sampled venous blood through a mechanism which remains to be elucidated.     

Sech~2(βr)型势阱中相对论粒子的束缚态

在Sech2(βr)型标量势与矢量势相等的条件下,严格求解了s波的Klein-Gordon方程和Dirac方程,给出了标量粒子和旋量粒子的束缚态波函数以及能谱所满足的方程。     

L-smooth半预开集与L-smooth半预不定映射

以文献[5]为基础，在L—smooth拓扑空间中定义了r-半预开集、r-半预闭集、r-半预内部、r-半预闭包，研究了它们的一些基本性质；同时，引入了L—smooth半预不定映射、L-smooth半预不定开映射、L—smooth半预不定闭映射及L—smooth半预不定同构映射的概念，给出了它们的等价刻画，并系统的讨论了它们之间的关系，推广了已有的结果。