Directionally controllable squeeze film damper using liquid crystal

Liquid crystals (LC) are characterized by its phase, which appears as an intermediate state between crystalline solid and isotropic liquid. This intermediate, phase is caused by orientation of molecules, and it can be controlled by an externally applied electric or magnetic field. Subjected to an electric field, the viscosity of the LC varies according to the applied electric field strength, which is called the electroviscous effect. This paper describes an application study of the electroviscous effect of a LC to a controllable squeeze film damper (SFD) for a rotating machine. A prototype controllable SFD using a LC was constructed and its performance was studied. It should be noted that the present SFD can produce anisotropic damping force for a flexible rotor at the supporting position, which enables us to stabilize a flexible rotor in a wide range of its rotating speed.     

钢管剪切正圆度的研究与实践

在分析钢管冲压剪切过程中剪切力变化以及钢管变形原因的基础上，采用变态对数曲线方程设计了新型的刀片形状曲线，大大地提高了钢管剪切正圆度。同时进一步提出了钢管的无变形剪切方法-双向切割法。     

用方向加速法求解结构的可靠度指标

针对现有结构可靠度指标计算中高度非线性功能函数导数计算复杂的问题，探索采用方向加速法来进行可靠度指标计算，避免了导数计算，简化了计算方法。     

Modelling direct sequence pseudonoise(dspn) satellite reception with directional antennas in the dense scatterer mobile environment

A geometric propagation model is developed for simulating the reception of direct sequence pseudonoise (DSPN) satellite signals by a directional or omni antenna in the dense scatterer mobile environment. The model is first validated for narrowband signals by a direct comparison of both simulated cumulative signal strength statistics and simulated diffuse Doppler spectra with classical theory. The model is then used to predict fading statistics for DSPN signaling, either with omni or directional antennas. As expected, the mitigation of fading is closely related to the ratio of DSPN chip duration to delay spread of the scatterer medium for both the omni and directional antennas.     

80m高钢筋砼烟囱的爆破拆除

论述了控制爆破拆除钢筋砼烟囱的方案设计与力学计算、爆破参数确定、施工方法、安全防护措施、震动监测和爆破效果.     

用于钻水平井的低密度水包油乳化钻井液

针对任平1井水平钻井的特点,研制了一种低密度、高油水比的水包油乳化钻井液。考察了乳化剂、增粘剂和配制工艺对乳状液性能的影响,评定了钻井液性能,介绍了现场应用情况。该钻井液性能稳定,润滑性好,净化井眼的能力强,能满足水平段钻井的要求。     

定向爆破拆除高危烟囱的实践

通过对已产生纵向裂缝、倾斜和基部风化剥蚀严重的高危烟囱的定向（向倾斜相反方向）倒塌爆破实践表明：设计中选用爆破参数及施工措施是有效的。     

转运站框架式厂房的爆破拆除

合山电厂转运站待拆五层钢筋混凝土框架式厂房西侧与被保护的引风机房相隔仅 0 3m ,北侧与工具房相连 ,南侧与需要保护的油池相邻。爆破切口布置在二层 ,并把最后一排柱的爆破部位提高到引风机房顶部以上 0 5m处 ,避免了后坐对引风机房的影响。通过预处理 ,将厂房与工具房分离。架设防护结构 ,阻挡飞石 ,保护了油池。文中介绍了爆高和爆破参数的选择、预处理、起爆破网路设计和安全防护措施。     

塔河油田特殊钻井条件下的录井技术

该文阐述了定向井、水平井和欠平衡钻井技术对传统录井方法的影响:钻时偏大、失真,岩屑细、代表性差,荧光常达12级、无意义,全烃值一般在5%以上,难以有效划分油气层;指出在特殊钻井条件下掌握设计指导思想,卡准重要层位是录井工作的关键,重点要参考组分分析数据、定量荧光分析数据和综合录井其它信息才能准确识别油气层。     

定向凝固的进展对高纯铝偏析法提纯工艺的影响

铝提纯工艺为高纯铝发展的关键。现在国内外通用的高纯铝制备工艺为三层液电解法和分步冷凝法。由于能耗高或提纯效率低，这两种工艺都不能完全满足当今工业发展的需要。针对当前广泛采用的凝固偏析法，结合定向凝固的新进展，讨论了改进结晶方式，提高提纯效率和生产效率的工艺方法。