构建农村和谐社会应加强农村环境保护

我国农村环境问题严重,必须采取多种措施加强农村环境保护,为构建农村和谐社会做贡献。     

浅议经评审的最低评标价法

经评审的最低评标价法是国际上普遍认可和通行的建筑工程招标方法。它有利于提高施工企业生产经营管理水平,节能降耗,向管理要效益,提高市场竞争力,最终促进施工企业生产力发展。就低价竞标的优点、存在问题及完善措施的具体做法做了叙述和探讨。     

水运工程监理工作的事前控制

结合工程监理实践．论述水运工程监理事前控制的必要性及主要工作、问题及对策。     

Fundamental formulation for frictional contact with graded materials

In the paper, we develop the fundamental solutions for a graded half-plane subjected to concentrated forces acting perpendicularly and parallel to the surface. In the solutions, Young's modulus is assumed to vary in the form of E(y) = E0e(ay) and Poisson's ratio is assumed to be constant. On the basis of the fundamental solutions, the singular integral equations are formulated for the unknown traction distributions with Green's function method. From the fundamental integral equations, a series of integral equations for special cases may be deduced corresponding to practical contact situations. The validity of the fundamental solutions and the integral equations is demonstrated with the degenerate solutions and two typical numerical examples.     

山区高速公路设计中应注意的几个问题

山区地形变化多端，在高速公路路线设计中，应灵活运用曲线定线，同时注重线形的连续性，使路线与地形相协调；在选择顺河绕行和隧道贯通方案时要谨慎比选；对山区生态环境的保护工作也要从路线设计之初予以考虑。     

浅谈公路桥梁的养护管理

随着交通建养工作的开展,其薄弱环节——桥梁养护管理也越来越为人们所重视。通过列举分析桥梁维修养护工作中常见的问题,研究解决问题的措施,可以达到提高桥梁养护管理水平的目的。     

计算机联锁图表的作用及改进探讨

主要介绍计算机联锁图表的作用,分析目前计算机联锁图表存在的一些问题。为适应计算机联锁车站的工程特点,提出对现有计算机联锁图表编制的改进原则和编制方法。     

STUDY ON INTELLIGENT DEVELOPMENT AND BEHAVIORAL PROBLEMS OF IRON－DEFICIENT SCHOOL CHILDREN

ＳＴＵＤＹＯＮＩＮＴＥＬＬＩＧＥＮＴＤＥＶＥＬＯＰＭＥＮＴＡＮＤＢＥＨＡＶＩＯＲＡＬＰＲＯＢＬＥＭＳＯＦＩＲＯＮ－ＤＥＦＩＣＩＥＮＴＳＣＨＯＯＬＣＨＩＬＤＲＥＮ（洪琦）（姚凯南）（刘灵）（赵兵健）ＨｏｎｇＱｉ；ＹａｏＫａｉｎａｎ；ＬｉｕＬｉｎｇ；Ｚｈ...     

The dynamic study of locomotives under saturated adhesion

In order to study the dynamic behaviours of locomotives under saturated adhesion, the stability and characteristics of stick–slip vibration are analysed using the concepts of mean and dynamic slip rates. The longitudinal vibration phenomenon of the wheelset when stick–slip occurs is put forward and its formation mechanism is made clear innovatively. The stick–slip vibration is a dynamic process between the stick and the slip states. The decreasing of mean and dynamic slip rates is conducive to its stability, which depends on the W/R adhesion damping. The torsion vibration of the driving system and the longitudinal vibration of the wheelset are coupled through the longitudinal tangential force when the wheelset alternates between the stick and the slip states. The longitudinal oscillation frequencies of the wheelset are integral multiples of the natural frequency of torsion vibration of the driving system. A train dynamic model integrated with an electromechanical and a control system is established to simulate the stick–slip vibration phenomenon under saturated adhesion to verify the theoretical analysis. The results show that increases of the longitudinal axle guidance stiffness and the motor suspension stiffness are beneficial to the stick–slip vibration stability and the locomotive's traction ability. The optimised matching of the longitudinal axle guidance stiffness and the motor suspension stiffness are helpful to avoid longitudinal resonance when the stick–slip vibration occurs.     

交通枢纽型商业中心的问题探讨及改善策略分析

城市商业中心区是城市中交通拥堵的多发地带,而交通枢纽及商业混合区域更是给交通带来了巨大的压力。文中结合镇江市城际枢纽站商业中心区的实例,对城市交通枢纽及商业混合区域的交通问题剖析,并对交通枢纽型商业中心区的交通改善策略进行了相应研究。通过采用公交优先、布置交通设施、构建先进的停车系统、合理组织交通流等措施,为该类地区的交通改善和治理提出对策,使得交通枢纽型商业中心的交通组织更加合理有序,尽可能地减少交通拥堵,促进城市和谐发展。