Induction of mosaic sex-linked recessive lethals in the different germ cell stages of Drosophila melanogaster by bleomycin

The dead-end filtration characteristics of the dimorphic yeast Kluyveromyces marxianus var. marxianus (formerly fragilis) NRRLy2415 were investigated for a range of mean cell morphologies, ranging from predominantly yeast-like to predominantly filamentous. Semiautomated image analysis was used to measure the mean cell specific surface area, Sv, and the mean ratio of cell length to equivalent cylindrical diameter, Ldm, in each broth. The method of Ju and Ho (Biotechnol. Bioeng. 1988, 32, 95-99) was used to show that for broths with Ldm values between 1.72 and 10.03, the voidage of cell pellets formed by centrifugation increased with increasing Ldm. In the pressure range 30-180 kPa, the specific filter cake resistance, alpha, was found to be related to pressure, DeltaP, through the equation alpha = alpha0(1 + kcDeltaP). The dependence of alpha0/Sv2 on Ldm was found to be qualitatively consistent with the pellet voidage data and the Carman-Kozeny equation. Considerably better agreement with the experimental data was obtained when the Kozeny constant, K, was treated as variable and related to Ldm through the equation K = 4.83 + 7.08 log10 Ldm. The cake compressibility constant, kc, was found to increase with increasing Ldm, a phenomenon consistent with the wide range of voidages that can be displayed by beds of long cylinders.     

济南珍珠泉大厦深基坑土钉支护技术

介绍了济南珍珠泉大厦基坑支护工程中，土钉在杂填土及淤泥质土中的应用及相应的处理措施。     

卫星通信技术的新进展

本文对国内外卫星通信的最新发展作了详尽论述;并综合概括了未来卫星通信技术的发展趋势;最后,对卫星通信市场进行了预测。     

低轨小型卫星的发展和应用

本文介绍低轨小卫星的发展和应用前景。低轨小卫星,体积和重量小,轨道低,功能单一,智能化,制造和发射都很容易,投资费用低,受到用户的普遍欢迎,有广阔的发展和应用前景。 小卫星在近几年发展迅速,应用广泛,已经受到世界各国的重视。在许多方面,已经应用小卫星和计划中应用小卫星的例子很多,本文只作简要介绍,目的在于引起人们的重视,发展我国的小卫星事业。     

海湾战争后防空系统及雷达电子设备的新发展

本文针对海湾战争后的新形势,介绍了战略防御的新构想、战术防空导弹系统及21世纪的防空概念,论述了AEW、AWACS、战场监视目标攻击雷达及其它雷达的最新发展情况,此外,还对国外的反隐身技术进展情况作了介绍。     

我国矿业城市实现可持续发展的途径分析

详细分析我国矿业城市可持续发展所面临的社会、经济、资源和生态环境等问题，提出了我国矿业城市应树立可持续发展目标及其内涵，系统分析矿业城市可持续发展的结构和模式，结合我国矿业城市发展存在的主要问题，以矿业城市可持续发展理念为指导，提出我国矿业城市实现可持续发展的途径及其建议。     

护坡排桩兼作地下室外墙承重结构的设计与施工

护坡排桩兼作地下室外墙承重结构的设计与施工刘引兰康忠山张家骥福满楼大酒店位于石家庄市中山东路１８６号，建筑面积约１万ｍ２，地上１０层，地下２层，框架结构，筏形基础。基坑开挖深度－１３．０ｍ，室内外高差０．６ｍ。该工程施工场地狭窄，基坑开挖时无法放坡。...     

地面NFJ耐磨面层施工工艺

1 NFJ简介 NFJ为耐磨、防锈、金属骨料的简称.耐磨面层为铁道部建筑科学研究院研究成果,应用于地面面层具有如下效果:抗压强度高(可达60～70MPa)、耐磨(重量磨耗率＜0.1%)、防锈(金属骨料可露天堆放,被水浸淋后无锈迹,可于使用前才与水泥拌合,地面面层施工后无锈迹)、面层表面光洁、不起砂、不起灰、耐磨寿命≥50年.     

Glomerular tip lesions--a newly described glomerular change

Glomerular tip lesion is a newly described histopathological lesion characterized by a focal and segmental widening of the mesangial matrix without hypercellularity together with capillary dilatation, hyaline exudation on the inside of capillary walls and occurrence of vacuolized cells, localized to the peripheral segments of the glomerular tuft. Clinically, these patients have a pronounced nephrotic syndrome with slightly reduced renal function, but terminal renal failure is seldom seen, even after many years of disorder. Two characteristic case histories are presented. The classification of this lesion among the glomerular disorders is at present uncertain. It may represent a transitional form between minor lesion nephritis and focal segmental sclerosis, a separate disorder, or a functional lesion associated with high proteinuria.     

新型蜜胺流化剂在混凝土工程中的应用

介绍了新型蜜胺流化剂在混凝土工程中的应用特性，通过配制大流动、商品及现浇混凝土，证明该流化剂具有坍落度损失少，流化保塑性好，减水增强，节省水泥，加快施工进度等特性。