曲柄摇杆机构的三圆图解设计法

这里探讨了对给定行程速比系数K，摇杆摆角ψ，另外再给定摇杆长度l3(机架长度l4)、曲柄长度l1(连杆长度l2)等，找出如何运用辅助圆图解设计曲柄摇杆机构的方法。     

流体在环形狭缝中流动时园柱体的微振动

本文讨论了在两个园柱体的环形狭缝中不可压缩流体的流动．在一定的假设下，运用流体力学方程和流体对柱体的作用方程，导出了附加质量和转动惯量、振动频率和衰减系数．并对文（１）中的某些结果进行了必要的修正．     

Recent investigations on some cubic Laves phase compounds of rare earth and transition metals

Pseudobinary alloy, Tb_0·27Dy_0·73Fe_2−δ , belonging to C-15 cubic Laves phase having MgCu₂-type structure, possesses large magnetostriction and high magnetomechanical coupling coefficient. The advantages of this material over existing piezoelectric materials, particularly for SONAR applications, are highlighted. Recent results on the influence of cobalt (Co) on magnetic and magnetomechanical properties of Tb_0·27Dy_0·73Fe₂ are discussed.     

粒界缓冲型展宽效应对PTC材料温度系数的影响

本文利用相变扩张理论分析了粒界缓冲型展宽效应对BaTiO_3系PTC陶瓷的介电系数及温度系数a_r的影响,指出了晶粒尺寸和温度系数的关系。     

Explosive Random‐Coefficient AR(1) Processes and Related Asymptotics for Least‐Squares Estimation

Abstract. Large sample properties of the least‐squares and weighted least‐squares estimates of the autoregressive parameter of the explosive random‐coefficient AR(1) process are discussed. It is shown that, contrary to the standard AR(1) case, the least‐squares estimator is inconsistent whereas the weighted least‐squares estimator is consistent and asymptotically normal even when the error process is not necessarily Gaussian. Conditional asymptotics on the event that a certain limiting random variable is non‐zero is also discussed.     

铁铝酸盐复合膨胀水泥化学预应力机理及其应用研究

本文阐述铁铝酸盐自应力混凝土的主要物理力学特征.研究了限制膨胀应变与配筋率之间的定量函数关系.通过正交试验和方差分析,确定了复合外加剂对其性能的影响.针对其在自应力管中的应用,提出多层中空圆柱理论计算模型,按弹性理论计算出自应力管初始应力分布规律.对比以前的线性理论计算误差,给出相应的修正系数.本文对类似的自应力混凝土,具有普遍的指导意义.     

Analysis of low load transients for the Vandellòs-II NPP: Application to operation and control support

The Technical University of Catalonia (UPC) has been jointly working with the Asociación Nuclear Ascó-Vandellòs (ANAV) for a number of years in order to establish, qualify and use best estimate (BE) models for the reactors under the control of ANAV. ANAV is the consortium that is responsible for operation of the Ascó and Vandellòs-II reactors. The reactors are Westinghouse-design three-loop PWRs with an approximate electrical power of 1000 MW. The existing integral plant models for each plant are currently used for many different purposes among which are support of plant operation and control. Quite a number of studies have been done in order to improve both safety and plant competitiveness. Most of these dynamic analyses were carried out in relation to transients starting at nominal full power or at least, very close to full power. This paper develops a specific use of the Vandellòs-II plant model for operation and control support at low power involving new ranges of system actuation parameters. It also examines scenarios that are somewhat different from those typically analysed. The study starts showing the results of an assessment case, which is a start-up test and provides some additional qualification, and subsequently attempts to establish calculations to support both an improvement in feed water controls and to set up operating recommendations for low-load manual operation of feed water turbo-pump. Both results hopefully, will produce an outcome, which leads to an improvement in safety and reduces reactor trip probability.     

卷边槽钢压杆考虑板组约束作用的屈曲系数

卷边槽钢压杆的局部屈曲具有相关性。《冷弯薄壁型钢结构技术规范》(GB50018-2002)提出适用于各种不同截面的板组约束系数的统一计算公式来考虑这种相关性。但由于板组组成的多样性,其是否合理,有待于进一步研究。借助ANSYS有限元分析软件,对卷边槽钢压杆局部屈曲进行分析,得到考虑板组约束作用的屈曲系数,并和国内外规范进行比较。结果表明,计算结果和英国规范吻合较好,我国规范偏于安全较多。借鉴英国规范的形式,给出考虑板组约束作用的屈曲系数的计算公式,这些公式可供进一步修订规范时参考。     

Vibrational Mode in Two-Dimensional Dust Monolayer with Finite Size Dust Grains

Vibrational mode in a two-dimensional dust monolayer is investigated by considering the finite size of dust grains. Each dust grain is assumed to be a negative point charge and a dipole moment due to the inhomogeneous charge distribution on its surface. The dispersion relation of the vibrational mode is derived. Both the self-excited and externally excited cases are discussed. It is shown that the mode is sensitive to the direction of the dipole moment.     

均布压力作用下厚壁圆管弯矩计算方法的探讨

建立了厚壁圆管弯矩计算公式，通过分析的均布压力作用下厚壁圆管与薄壁圆管压力相对误差，给出了厚壁圆管与薄壁圆管分类原则，了解和掌握这一原则对工程师大有禅益。