福州洪山大桥支座整体更换施工的方法和措施

本文针对国道316线福州洪山大桥支座整体更换工作中所采用的主要施工方法和措施进行介绍,对类似桥梁的养护工作具有指导意义。     

Frequency response function of magnetic bearings using high-temperature superconductor

A high-temperature superconductor YBa₂Cu₃O_7-x with strong pinning force has allowed stable magnetic suspension with no control to be developed. Two types of superconducting magnetic bearings (SMB) using YBCO and permanent magnet were assembled. The two types are radial and axial. The dynamic stiffness of each SMB as it was cooled down under a magnetic field by liquid nitrogen was measured both radially and axially. As a result, it was found that the spring constants of these SMBs were almost as large as a practically desirable value; however, their damping coefficients were lower than the practical level. These findings are useful as one of the data bases for development of an optimum SMB design to support the weight of rotors in an axial direction.     

An examination of the effect of composite constituent properties on the notched-strength performance of composite materials

The effect of matrix and fiber properties on the strengths and failure processes of notched, continuous-fiber composite specimens has been investigated. Bearing, open and filled hole tension and compression tests were conducted on AS-4/3501-6, IM-8/3501-6, AS-4/APC-2 and IM-8/APC-2 specimens. Failure characteristics of tested specimens were studied by fractographic techniques. Failure progression was tracked by means of incremental loading, radiography and fractographic inspection.     

高应力水平下滚动轴承疲劳寿命试验研究

通过在三种不同的强化负荷下进行深沟球轴承疲劳寿命试验，并与常规试验一组结果对比。结果表明，适当地加大滚动轴承疲劳寿命试验负荷，可以大大缩短试验时间，而疲劳寿命依然服从Ｗｅｉｂｕｌ分布，且与常规试验结果基本一致，同时疲劳破坏的形式仍是表面下萌生裂纹，然后扩展至表面形成剥落。     

超高吨位灌注桩静载试验中的预应力混凝土反力装置

在复兴大桥超高吨位灌注桩的静载试验,预应力混凝土反力装置替代了传统的钢梁反力系统。这套装置主要包括预应力锚桩、预应力承台与预应力反力梁。试验结果表明,直接获得超高吨位大直径嵌岩桩的极限承载力相当不易,而对这类问题预应力混凝土反力装置是值得考虑的。     

As Hangs the Flexible Line: Equilibrium of Masonry Arches

In 1675, English scientist Robert Hooke discovered “the true... ...manner of arches for building,” which he summarized with a single phrase: “As hangs the flexible line, so but inverted will stand the rigid arch.” In the centuries that followed, Hooke’s simple idea has been used to understand and design numerous important works. Recent research at MIT on the interactive analysis of structural forces provides new graphical tools for the understanding of arch behavior, which are useful for relating the forces and geometry of masonry structures. The key mathematical principle is the use of graphical analysis to determine possible equilibrium states.     

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本文介绍了陕北气区陕35井第一次下光油管(即不带封隔器)酸化的施工情况,并结合该地区的地层压力特征分析了光油管酸化施工的可行性及应用限度。     

K202A压缩机电机轴瓦超温的原因及对策

K202A压缩机的电机轴瓦采用的是动压轴承,经常持续升温。其主要原因是由于滑动轴承和轴之间是半液体摩擦,润滑油在轴颈及轴瓦之间没有形成具有足够压力的油膜,造成滑动轴承和轴局部形成半液体摩擦而产生大量的热量,又无法被带走引起的。文章通过验算K202压缩机电机滑动轴承温度,分析影响滑动轴承运行温度的因素,提出在原滑动轴承上开油楔及加装一台齿轮油泵为滑动轴承强制润滑,并且通过联轴器把电机和压缩机连接起来,用压缩机轴瓦托起电机轴,使电机轴颈和轴瓦之间处于液体摩擦状态,可有效地降低滑动轴承的运行温度。     

浅析朱赛普·特拉尼的代表作法西斯大厦

介绍了法西斯大厦的基本情况，通过对朱赛普·特拉尼的代表作法西斯大厦的空间结构、承重结构、围护结构、立面结构的分析，以使人们更深刻地理解特拉尼的建筑思想，探索其积极的现实意义。     

下扬子北缘前陆盆地构造变形样式

下扬子北缘前陆盆地经历了印支、燕山、喜山等多期构造改造,构造环境经开裂扩张—碰撞拼合—拉伸断陷等多次转换,最终形成了上部拉伸、中部逆冲推覆、下部拆离滑脱的"三层楼阁"式分层构造变形组合的构造几何学模式.其构造变形主要受中三叠世扬子地块与华北地块的陆—陆碰撞造山作用控制,具有横向上强弱分带、垂向上形变分层的特征.可划分为伸展变形、冲断褶皱变形、拆离滑脱变形等3种构造变形样式.