Isolation of antimicrobial agent from the marine algae Cystoseira hakodatensis

Cystoseira hakodatensis is an unutilised brown algae belonging to family Sargassaceae. A crude methanol extract from the algae showed inhibitory effects on the growths of Bacillus cereus and Bacillus licheniformis. To isolate the major antimicrobial agent, a sequential active‐guided isolation procedure was applied: liquid–liquid extraction, column chromatography and bio‐autography. A marked antimicrobial agent (active α) was isolated in hydrophobic fraction and was determined to phenolics without carbohydrates and proteins by phytochemical test. Regarding the antimicrobial potential, the isolated active α showed better inhibitory effects against B. cereus and B. licheniformis at 2 and 4 times of lower concentrations (62.5 and 31.3 μg mL^?1) in comparison with epigallocatechin gallate. These results showed that C. hakodatensis is a potential source of antimicrobial agent capable of preventing the growth of the two bacteria.     

一种微透镜阵列的研制

介绍一种利用表面张力的作用、以光纤作材料、用分离的自聚焦透镜制作微透镜阵型的方法，这种方法具有制作工艺简单、无须昂贵设备等优点，用此方法实际制作了具有良好连续面型的微透镜阵列，并对制作的微透镜阵列进行了测试，效果较好。     

低密度微泡沫压井液的研究与应用

吐哈油田部分区块地层压力系数小于0.9,常规水基压井液对储层伤害大,若使用油基压井液成本高,环境污染严重。通过实验优选出了一种低密度水基微泡沫压井液。该压井液具有密度低、泡沫强度高、稳定性好、携砂能力强等优点。现场应用表明,低密度微泡沫压井液稳定时间大于48 h,密度在0.70~0.99 g/cm3之间可调,抗油污染能力强,抗油大于8%,抗温在100℃以上,岩心污染后渗透率恢复值大于80%;并且施工方便,成本低,具有储层保护能力,使用微泡沫压井液的井表皮系数在0.20~2.34之间。     

High-load, squeeze action linear bearings with beam deflection

The literature provides little information on high-speed, high-normal-load, plain linear bearings, although the case for two rigid surfaces in relative linear motion can readily be solved by assuming squeeze action resistance. A new genus of internal combustion engines based on the Stiller-Smith mechanism incorporates connecting rods constrained by linear bearings, with the central normal load on the rod restricted by an oil film. A general analysis takes into account the bending of the rod, when the distributed oil film pressure resists the distributed load on the elastic rod. Design charts result that yield the dimensionless velocity at which the rod sinks in the oil as a function of the dimensionless load and the bearing clearance, and predict the deflection of the beam. The rod clearance history simulations for the Stiller-Smith engine compare favourably with computations for the rigid beam, confirming the analysis technique.     

单轴-平面W型复合锶铁氧体的制备及其吸波特性研究

用草酸盐共沉淀和微量掺杂法研制六角晶系W型Ni,Zn,Co,Al多元复合锶铁氧体，通过调节Ni2W同Co2W的摩尔比例，可使该种铁氧体易磁化方向从C单轴型向垂于C轴的平面型转化，控制置换锶铁氧体中部分Fe3 的微量掺杂Al3 ，可以调整4πMs值，提高磁晶各向异性场，测试分析了5种不同含Co量的W型复合锶铁氧体粉料涂层的吸波特性，发现其自然共振吸收峰随Co含量增加向低频方向偏移，最高吸收峰可达32．8dB，是适用于电子隐形技术的高品位的微波吸收剂。     

Possibilities and extension of XRD material response analysis in failure research for the advanced evaluation of the damage level of Hertzian loaded components

Due to clearly distinguishable damage symptoms, it is differentiated between the surface and sub‐surface failure mode of rolling bearings. Material states red out by X‐ray diffraction (XRD) residual stress measurements point to a variety of loading conditions especially at raceway surfaces that are associated with several competing failure mechanisms. The corresponding lifetime reduction can range from the lower fatigue strength region to material ratcheting in extreme cases. Relevant position of the microstructural changes and nature of the failure mechanisms are characterized. The time alteration of the XRD material parameters measured at or near the surface and at the depth of the maximum equivalent stress correlates, in a different manner, with the statistical parameter of the 10 % bearing life. Both failure modes are illustrated by concrete examples. Contaminated lubricant and boundary lubrication, which represent practically important surface‐induced failures, are discussed in more detail. Gray staining, i.e. shallow pitting, often occurs without distinct indication of global material aging by means of XRD characteristics. Here, scanning electron microscopy observations and electron microprobe analyses point to corrosion fatigue as acting surface failure mechanism. The interaction between material and lubricant under complex loading regimes particularly of mixed friction and corrosion opens further failure research areas in the field of tribology.     

住宅建筑结构中隔震技术的应用和经济评价

对当前隔震系统做了简单介绍 ,介绍了基础隔震的技术和施工方法等。讨论在住宅结构中推广隔震技术的方法 ,对各种类型的住宅结构做经济评价 ,讨论推广的可能性和难点。     

发电机用DJL350磁极钢板的开发与应用

本文论述了高强度冷轧磁极板的试制性研究，应用性研究及在开生桥机组上的实施。通过与国外材料的对比，研究了材料的化学成分、力学性能、磁性能、金相组织及其与性能的关系。并对其实际应用效果进行了分析总结。     

单片机在监控同步电动机运行功率因数中的应用

介绍如何利用单片机自动控制同步电动机运行时的功率因数。