卫生间盥洗室渗漏的防治

本介绍了管道穿楼层处防漏的正确方法及便槽、便坑防渗漏的措施，同时又介绍了发生渗漏后修补的方法。     

DXB_2-12型电镜透镜电源原理分析与故障维修

本文概述了ＤＸＢ２—１２型电镜的透镜电源原理及几例特殊故障的分析要点和检修方法。     

气制动阀密封特性测试技术的研究

讨论了密封特性压力测试法的局限性,论述了差压测试法的优越所在及实现方法。差压法比传统的压力法,可提高气制动阀密封特性测试精度达100倍。差压法不仅适用于气制动阀密封特性测试,而且还可应用于一般气动系统的泄漏量测试。     

Survival of Clarias gariepinus fry in earthen ponds: Effects of composts and leaks

To inform decisions on improving the yields of African catfish Clarias gariepinus fingerlings in earthen ponds, the hypothesis that composts and leaks were partly responsible for usually low and variable fry survivals was tested, through comparison of treatments and simple regression. The occurrence of amphibians was significantly higher (P < 0.05) and survival of fry was significantly lower (P < 0.02) in ponds with composts than in those without. The survival of fry and fingerlings in earthen ponds was negatively correlated with their night leaking rates and regression analysis yielded the equations y = − 13.31x + 82.56 for fry and y = − 6.97x + 95.29 for fingerlings, where y is the survival of fry or fingerlings in a holding pond and x is the leaking rate of the pond. Realizing how negatively the existence of composts and leaks could affect the survival of fry and fingerlings, fertilizing unfenced ponds with composts and sterilizing nursery ponds by drying were proscribed.