不等厚板过渡削薄对接焊缝的超声波探伤

不等厚板经过渡削薄处理后的对接焊缝,由于厚度的不均匀,射线穿透时的衰减不一样,对射线检测带来很大的麻烦。常用的超声波探伤方法在定位和定级方面比较困难,本文给出利用现在先进的数字式超声波探伤仪进行准确探伤的方法。     

The role of the surface free energy in the selection of a suitable excipient in the course of a wet-granulation method

Pellets containing metronidazole were produced in a centrifugal granulator, with hydroxypropylcellulose (Klucel LF®) as binding agent, and corn starch, microcrystalline cellulose (Vivapur 101®) and lactose as excipients. The wettability of the pharmaceutical powders was assessed by means of contact angle measurements, and the dispersive and polar surface energies were determined. The spreading coefficients, the work of adhesion and the work of cohesion were calculated and correlated with the pellet properties (friability, bulk and tapped density, and porosity). The aim was to investigate the role of the surface free energy of one- and two-component powder compositions in pellet production. The interactions between the particles were found to be connected with the measured pellet parameters. It was concluded that, in the course of the growth of the pellets, the particle sizes of the pharmaceutical powders and the interactions between them are important. If the work of cohesion of the binder is lower than the work of cohesion of the substrate and the work of adhesion, then the optimal amount of the binding agent is that which coats the particles uniformly in minimal quantity and in continuous layer.     

凉水塔技术研究与探讨

通过对我厂引进的大型进口设备———Marley—600型冷却塔进行技术改造情况的介绍,具体分析了进口材料与国产材料的本质区别,并具体介绍了我厂的使用情况。此次技术改造在大化肥行业是首次进行,并取得了成功。论证了进口设备走国产化道路的必然性及可行性,从而为我国的其他大型Marley—600型冷却塔设备走国产化道路作了较好的铺垫。     

塔板布置的计算机辅助设计

提供了一种简单而有效的利用计算机辅助进行塔板布置的方法。给出了相应的计算内容和程序。有较好的通用性。适用于浮阀塔板和筛孔塔板。     

各向异性板弯曲的数值解

提出一种计算各向异性板挠度的数值方法。导出与铰支和自由边界条件相对应的虚结点位移递推公式。为说明该方法，对45°单向复合材料板的挠度进行了两个实例计算，并对计算结果的正确性作了实验验证。     

阴图PS版感光层的光交朕

阴图ＰＳ版感光层的光交朕曹曙光，王仁祥，曹维孝（北京大学化学与分子工程学院，北京１００８７１）关键词重氮树脂；成膜树脂；阴图ＰＳ版；光交联阴图ＰＳ版感光层主要是由成膜树脂和感光树脂组成。感光树脂一般是二苯胺或取代二苯胺重氮树脂．成膜树脂类型较多。就成...     

珍珠岩助滤剂在天然卤水精制中的应用

通过实验 ,得出在天然卤水制小苏打的生产过程中 ,使用珍珠岩助滤剂对天然卤水精制是可行的。     

压力容器用封头制造质量控制和专业化生产发展方向

中国法规首次对压力容器等特种设备用封头实施制造资格许可和强制的监督检验制度。本文根据法规标准的规定,对压力容器封头制造质量控制和专业化生产发展方向的要求作一系统的综述,以提高压力容器产品的整体质量,确保特种设备安全万无一失。     

Forces required to jettison a simulated S92 passenger exit: Optimal helicopter underwater egress training techniques

This paper outlines the first known examination of the forces required to jettison a simulated exit used during helicopter underwater egress training (HUET). To capture the forces placed on the simulated cabin exit, a purpose build force plate was designed to replace an existing simulator exit used during HUET. A 25-point map was created to identify specific jettison forces required across the entire exit surface. Ten participants completed a total of 120 underwater egress sequences in–air and in-water from a normal flight and fully compressed crash attenuating seat position. The results indicate that the force required to jettison the simulated exit is significantly different in relationship to location on the exit surface. From the results, it can be concluded that helicopter underwater egress training protocols should ensure that offshore candidates are informed of the different force requirements as well as have the opportunity to practice jettisoning a high physical fidelity exit from a fully compressed crash attenuating seat.     

基于条件随机场的低图像质量车牌字符分割

提出一种基于条件随机场的车牌字符分割算法,能够对光照不均、相机拍摄角度造成的低图像质量的车牌图像,特别是日益增多的车牌边框与字符相连接车牌图像进行有效的字符分割。算法首先进行车牌图像校正,然后利用标注车牌数据进行模型学习,对车牌图像像素列进行分类识别,最后组合成车牌字符分割结果。理论分析与实验结果验证了算法的有效性。