浅谈门式刚架轻型钢结构厂房中抗风柱的设置

通过对抗风柱上下端的节点几种形式进行分析比较,提出建议性的节点连续方式。     

羟基磷灰石涂层人工关节的应用研究

采用人工合成高纯度的羟基磷灰石粉末，喷涂在具有注册证的钛合金和钴铬钼合金人工关节上。通过生物学基础检测、动物实验和临床试用，证明所制作的各种羟基磷灰石涂层人工关节，能诱发骨质生长，起生物固定作用，对治疗丧失功能的骨胳效果甚佳。     

氧气合理利用决策支持系统和空分装置操作仿真系统

分析了钢铁企业空分系统能源管理的特点 ,并开发出降低空分能耗的应用软件 :氧气合理利用决策支持系统和空分装置操作仿真系统。前者可为决策者提供全面的辅助决策信息和决策支持以降低氧气放散 ,实现氧气的合理利用 ;后者既可实现空分装置运行操作的仿真 ,也可实现空分装置的仿真实验和仿真操作 ,为实施空分装置的节能优化运行提供技术支持     

Investigation on vapor-cooled current leads operating in a pulse mode

This paper describes transient numerical modeling for thermal characteristic of vapor-cooled current leads under pulse operation. The transient thermal analysis considers the temperature difference between a helium gas flow and a copper lead with temperature dependent properties of helium gas, copper and stainless steel. The numerical analysis was validated by an experiment with commercially available 100 A vapor-cooled current leads. A proper overloading factor calculation and the effect of intermediate cooling are presented for the current leads under pulse operation, which can significantly reduce heat input to a cryostat.     

Life Calculations for Header – PGV-1000 Steam Generator Connector Weld Joints under NPP Service Conditions

The procedure for calculating the life of header – steam generator connector weld joints is proposed. It allows for running out the material plasticity reserve upon static cyclic elastoplastic loading as well as operating conditions, local stress concentrations, and residual stresses after welding.     

Analysis of the Ductile Strength of Welds Weakened by Notches in Longitudinally Welded Pipes of Large Diameter by the Method of Slip Lines

We study the stressed state of an inhomogeneous welded joint containing an interlayer of a more high-strength material under the action of tensile loads. It is assumed that the contact boundary has a cracklike defect. We deduce analytic dependences of the fracture load on the mechanical inhomogeneity of the joint, thickness of the interlayer, and depth of the defect. The maximum depth of the defect to which the joint is insensitive is established. The proposed theoretical results are innovative and agree with the experimental data obtained for specimens cut out from a pipe of 14KhGS steel.     

量子计算机进展

对近几年量子计算机从实验室走向实用化的重要进展作了一个简要综述。概述了量子计算机的优点，给出了不需要量子交缠的量子计算方法以及量子计算机的程序——量子幺正操作的特性，介绍在克服退相干所带来的困难方面所取得的进展以及大尺度和实用化方面的进展，最后给出概要的评述。     

SLIMLINE+K型多功能撬装双滚筒试井绞车简介

SLIMLINE K型多功能撬装双滚筒试井绞车为整体式结构，多用于海上平台，可进行电子压力计和机械压力计试井，以及井下工具的投放、震击、打捞等完井作业。该试井绞车采用先进的数控技术，使起下纲丝／电缆实现自动化控制，该系统能够对斜井、定向井进行随钻测试。     

Damage mechanism in weldment of 2.25Cr-1Mo steel under creep-fatigue loading

The purpose of this study is to clarify damage process of “Type IV cracking” in weldment of a 2.25Cr-1Mo steel and to propose a micro damage prediction method. From continuous observation under a creep-fatigue test, it was found that spherical shape voids initiated and grew on grain boundaries in fine grain region and these voids grow continuously by changing their shape to crack-like. Both spherical and crack-like void growth rate equations were derived from the proposed void growth model. It was indicated that measured void growth rate under the creep-fatigue loading was well predicted by the growth rate equations.     

The stiffness matrix in elastically articulated rigid-body systems

Discussed in this paper is the Cartesian stiffness matrix, which recently has received special attention within the robotics research community. Stiffness is a fundamental concept in mechanics; its representation in mechanical systems whose potential energy is describable by a finite set of generalized coordinates takes the form of a square matrix that is known to be, moreover, symmetric and positive-definite or, at least, semi-definite. We attempt to elucidate in this paper the notion of “asymmetric stiffness matrices”. In doing so, we show that to qualify for a stiffness matrix, the matrix should be symmetric and either positive semi-definite or positive-definite. We derive the conditions under which a matrix mapping small-amplitude displacement screws into elastic wrenches fails to be symmetric. From the discussion, it should be apparent that the asymmetric matrix thus derived cannot be, properly speaking, a stiffness matrix. The concept is illustrated with an example.