Liquid crystalline polyesters with two-dimensional mesogenic units

Summary A series of thermotropic, liquid crystalline (LC) polyesters was prepared in which the mesogenic group contained an unusually large, polarizable pendant group in an attempt to increase intermolecular interactions so as to impart a more isotropic character to the mechanical properties of the solid polymer. The series included repeating units containing main chain, polymethylene flexible spacers of increasing lengths. All of the polymers formed stable nematic LC phases and had relatively low melting temperatures, but recrystallization from the melt was very slow in each case. Dedicated to Prof. Dragutin Fleš on the occasion of his 70th birthday     

破片式战斗部优化设计技术研究

侧重研究了破片式战斗部装药外形的优化设计技术。提出了装药外形与破片飞散特性（如破片飞散角，分布带宽等）之间的数学描述；建立了圆弧和对数螺线装药外形母线与战斗部其他设计参数间的数学模型。在假定约束条件下，优化设计了破片了聚焦式战斗部的结构参数；静爆试验结果表明，破片分布与理论计算吻合较好。     

Effect of Processing Temperature on the Morphology of Silicon Carbide Whiskers

Two kinds of SiC whiskers were annealed at temperatures similar to those for the processing of ceramic matrix composites. The morphology and structure of the as-received and postannealed whiskers were investigated by SEM, TEM, and XRD, and the influence of processing temperature on the mechanical properties of ceramic matrix composites was discussed.     

MX345芯片及单片机控制

MX345芯片用于产生模拟信令—CTCSS单音.本文在介绍MX345编码/解码器工作原理的基础上,设计出MX345芯片与单片机的接口电路.最后给出控制软件.     

WATCHDOG在汽轮发电机组状态监测系统中的应用

本文介绍一种适合于汽轮发电机组状态监测系统的“看门狗”功能,它可以在很短时间内发现由于外界干扰而导致的计算机的锁死,并马上自动使计算机恢复正常运行。从而提高在线状态监测系统的可靠性。     

Crystallite growth characteristics in superfine zirconia powders and compacts

Crystallite growth characteristics of coprecipitated superfine zirconia powders have been investigated. It was found that the crystallite growth in powders follows a cubic law at 800 and 1000°C; however, the crystallite size data for compacts of both Y-TZP and YSZ cannot be fitted with a traditional parabolic or cubic law, but with a linear relation between crystallite size and the logarithm of time. In addition, it was also found that the degree of agglomeration of the powders can affect the crystallite growth.     

广西某矿区托帕石的宝石学特征

广西某矿区的脉石矿物——黄玉分三个世代,其中第三世代的黄玉晶体无色透明,重量大于0.9克拉,瑕疵不明显,密度(3.50)、硬度(7.8430)和折射率(1.6330)等特征均达宝石级,经系统研究测试,可以命名为托帕石(Topaz)。     

大系统的局部分散镇定

本文给出了一种计算范德蒙矩阵逆的模的方法.利用这种方法,得到了可以用局部分散 状态反馈镇定的一类大系统.与过去的结果比较容易计算,且不要求关联项中很多元素为零.     

二硫代磷酸硫化氧钼与硫,磷添加剂的复配特性研究

研究了二烷基二硫代磷酸硫化氧钼（ＭｏＤＴＰ）摩擦改进剂及其与硫、磷、硫－磷型添加剂复合的抗磨减摩性能。试验表明，经过适当复配后，这类合活性元素的添加剂对ＭｏＤＴＰ的抗磨减摩性能均有增效作用，同一类型添加剂的活性愈高，增效作用愈显著。同时利用扫描电镜和Ｘ－射线能谱仪进行摩擦副表面膜的形貌照相及元素分析，对复合作用的机理进行了初步探讨。     

Evaluation of accuracy of measuring intraocular pressure by handheld non-contact applanation tonometer

PURPOSE: To evaluate the accuracy of measuring intraocular pressure by handheld non-contact applanation tonometer. METHOD: 58 patients' (113 eyes) intraocular pressure were measured by Keeler, non-contact tonometer and R 900 Goldmann applanation tonometer and the results of measurement of intraocular pressure by the two kinds of tonometers were compared. RESULT: The mean intraocular pressure measured by non-contact is 16.31 +/- 5.59 mmHg and 17.49 +/- 6.13 mmHg (1 mmHg = 0.1333 kPa) by Goldmann applanation tonometer, respectively. There was no statistical significance to be found (P > 0.05) between the two methods. By linear correlation and regression analysis, a positive correlation was found between the two methods (r = 0.8942, b = 0.8154). CONCLUSION: The handheld non-contact tonometer has the same accuracy and reliability of measurement of intraocular pressure comparing with Goldmann applanation tonometer, and it can be used in glaucoma clinic and screening.