Preparation and Properties of Hydroxyethyl Methacrylate Chemically Modified Temperature-Sensitive Microgels

A novel series of poly (N-isopropylacrylamide-co-hydroxyethyl methacrytate) (p (NIPAM-co-HEMA))microgels were prepared through precipitation polymerization. Nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV) and dynamic light scattering (DLS) were employed to characterize the microgels. The experimental results indicate that the prepared microgels with narrow distribution remain good temperature sensitivity after incorporation of functional -OH groups. In marked contrast to the general rule, incorporation of hydrophilic HEMA makes the volume-phase-transition temperature shift to the lower temperature due to the strong intermolecular H-bonding between amide and -OH groups, -OH and -OH groups.     

浅谈桥梁初始缺陷基桩屈曲

针对高速公路桥梁基桩在施工过程中可能产生的初始缺陷,采用常规有限元法、非线性有限元法、失稳路径的弧长法分析了存在初始缺陷时桥梁基桩屈曲的规律。     

Geometrical design of blade＇s surface and boundary control of Navier-Stokes equations

In this article a new principle of geometric design for blade＇s surface of an impeller is provided. This is an optimal control problem for the boundary geometric shape of flow and the control variable is the surface of the blade. We give a minimal functional depending on the geometry of the blade＇s surface and such that the flow＇s loss achieves minimum. The existence of the solution of the optimal control problem is proved and the Euler-Lagrange equations for the surface of the blade are derived. In addition, under a new curvilinear coordinate system, the flow domain between the two blades becomes a fixed hexahedron, and the surface as a mapping from a bounded domain in R2 into R3 , is explicitly appearing in the objective functional. The Navier-Stokes equations, which include the mapping in their coefficients, can be computed by using operator splitting algorithm. Furthermore, derivatives of the solution of Navier- Stokes equations with respect to the mapping satisfy linearized Navier-Stokes equations which can be solved by using operator splitting algorithms too. Hence, a conjugate gradient method can be used to solve the optimal control problem.     

混凝土空心板梁外观质量缺陷与防治

针对混凝土空心板梁预制生产过程中产生的外观质量缺陷 ,分析成因并提出修补方法和预防措施 ,使梁的外观质量得到了提高。     

铸铁件缺陷分析及对策

基于实例对铸铁件生产中的气孔、粘砂和表面缩陷等缺陷进行了分析,并进行了工艺改进,消除了这几类铸造缺陷.     

铸渗技术制备金属基表面复合材料的研究进展

铸渗是一种制备金属基表面复合材料的新技术。本文对铸渗技术制备金属基表面复合材料进行了综述并对铸渗金属基表面复合材料的形成机理进行了分析和讨论，对铸渗金属基表面复合材料的应用进行了介绍。     

FIDIC合同条件中缺陷责任期的监理

我国的公路建设正在向国际化发展,作为世行所认可的FIDIC合同条件,给各国的公路建设提供了行动的指南。缺陷责任期是公路建设中非常重要的一个阶段。结合FIDIC合同条件阐述了在缺陷责任期内如何做好监理工作。     

钻孔灌注桩的几种质量缺陷原因与预防处治实践

着重结合工程实际对桥梁钻孔灌注桩缺陷的形成原因进行分析,并将几种较成功的处理方法作介绍,供同行交流。     

连续T梁腹板缺陷分析与修复处治

预应力混凝土T梁桥是我国公路桥梁的常见桥型,实际应用中腹板缺陷时有发生。针对某预应力混凝土连续T梁腹板缺陷,通过影响分析和结构计算,分析应力与变形状态,提出处治措施,供同类型问题处治的设计与施工借鉴。