助催化剂对TiCl_4/MgCl_2催化丙烯高温聚合的影响

研究了助催化剂种类(三甲基铝、三异丁基铝、三正己基铝、三乙基铝和甲基铝氧烷)及其含量对无内、外给电子体的TiCl4/MgCl2催化剂催化丙烯高温(100℃)聚合性能的影响,并用结晶分级分析、示差扫描量热和凝胶渗透色谱等方法分析了所得聚丙烯的结晶熔融行为和微观结构。实验结果表明,聚合温度从70℃升至100℃时,TiCl4/MgCl2催化剂的定向能力基本不变;100℃聚合时,以烷基化能力较弱的三异丁基铝为助催化剂时TiCl4/MgCl2催化剂的活性最高,而采用烷基化能力最强的三甲基铝为助催化剂时TiCl4/MgCl2催化剂的活性最低;100℃聚合时,助催化剂的种类对TiCl4/MgCl2催化剂的定向能力影响很小。     

高速线材生产的弹簧钢盘卷的表面脱碳分析

从金相角度对高线生产的弹簧钢盘卷的表面脱碳进行了分析，找出相关的影响因素，并针对实际情况提出了相应的改进方法。     

EXPERIMENTAL INVESTIGATIONS ON LONGITUDINAL DISPERSION CHARACTERISTICS OF TIDAL RIVERS

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＵｎｄｅｒｔｈｅｉｎｆｌｕｅｎｃｅｏｆｎａｔｕｒａｌｔｉｄｅｓ,ｔｈｅｉｎｔｅｒａｃ ｔｉｏｎｓｂｅｔｗｅｅｎｆｌｏｗｆｅａｔｕｒｅｓａｎｄｐｏｌｌｕｔａｎｔｌｏｎｇｉｔｕｄｉｎａｌｄｉｆｆｕｓｉｏｎｉｎｔｉｄａｌｒｉｖｅｒｓａｒｅｉｍｐｏｒｔａｎｔｆｏｒｗａｔｅｒｅｎｖｉ ｒｏｎｍｅｎｔｒｅｃｔｉｆｉｃａｔｉｏｎｉｎｅｓｔｕａｒｉｎｅｒｅｇｉｏｎｓ.Ｔｈｅｄｉｆｆｕ ｓｉｏｎａｎｄｔｒａｎｓｐｏｒｔｏｆｐｏｌｌｕｔａｎｔｉｎｎａｔｕｒａｌｒｉｖｅｒｓｆａｌｌｉｎ ｔｏｍ…     

东营凹陷南斜坡储集层成岩作用及对储集性能的影响

东营凹陷南斜坡孔店组岩石类型以岩屑长石砂岩为主 ,长石砂岩和岩屑砂岩次之 ,其中岩屑长石砂岩含量超过 90 %。砂岩成岩作用包括压实作用、胶结作用、溶蚀作用、交代作用等 ,其中胶结作用使储层原生孔隙迅速变差 ,而溶蚀作用是次生空隙发育的主要因素。孔店组砂岩成岩作用进入晚成岩A期 ,期间经历了早成岩A期、B期。影响成岩作用的主要因素为构造演化背景、岩石成分、沉积环境、孔隙流体性质等。     

Elastic solutions of a cylindrical rod containing periodically distributed inclusions with axisymmetric eigenstrains

Summary. In this paper, we give the elastic solution for a special type of microstructure – a circular cylindrical rod containing periodically distributed inclusions along its axial direction. Each inclusion has the same uniform axisymmetric transformation strain (eigenstrain). Analytical elastic solutions are obtained for the displacements, stresses and elastic strain energy of the rod. The effects of microstructure and its evolution (growth of inclusions) on the elastic stress and strain fields as well as the strain energy of the rod are quantitatively demonstrated. As a result of such microstructure evolution nominal stress-strain relation with strain softening is derived for a rod under uniaxial tension.     

Postbuckling analysis of plates on an elastic foundation by the boundary element method

The postbuckling behavior of plates on an elastic foundation is studied by using the boundary element method (BEM). A new fundamental solution of lateral deflection is derived through the resolution theory of a differential operator, and a set of boundary element formulae in incremental form is presented. By using these formulae, the BEM solution procedure becomes relatively simple. The results of a number of numerical examples are compared with existing solutions and good agreement is observed. It shows that the proposed method is effective for solving the postbuckling problems of plates with arbitrary shape and various boundary conditions.     

时序电路逻辑初始化问题研究

讨论同步时序电路初始化问题,提出了一种基于电路存储元件逻辑定级和可控性分析的同步时序电路逻辑初始化方法。同时也给出了针对ISCAS89电路的一些实验结果。     

Cu－MnO_2同槽电解半工业试验研究

提出了Ｃｕ－ＭｎＯ＿２同槽电解的新工艺，在同一电解槽同时得到电铜和电解二氧化锰两种产品，该新工艺具有低电耗、低酸雾污染和低酸耗等优点．     

具有初曲率板弯曲的边界元分析

由于具有初曲率板弯曲问题的控制微分方程较复杂，直接求解原问题基本解推导边界积分方程较为困难。本文通过引入等效荷载，将此问题的控制微分方程化成与普通板弯曲基本方程形式相同的微分方程，利用一般求解板弯曲问题的边界元法迭代求解，建立了分析具有初曲率板弯曲问题的边界元法。算例表明本方法理论准确、精度良好。     

T_C≥400°C高温PTC陶瓷的研制

利用国产原料，采用传统的陶瓷材料制备工艺，研制了居里温度ＴＣ≥４００°Ｃ的高温ＰＴＣ陶瓷，制成了居里温度ＴＣ＝４１２°Ｃ，电阻Ｒ≤１０３Ω，ｌｇ（Ｒｍａｘ／Ｒｍｉｎ）＝４的高性能ＰＴＣ热敏陶瓷材料