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111.
GBF现浇混凝土空心楼盖的施工   总被引:2,自引:0,他引:2  
介绍了新型建材GBF(高强度复合薄壁管)现浇混凝土空心楼盖新技术的施工、GBF管的检测以及施工中较难掌握的一些技术要领和现场施工经验。  相似文献   
112.
A failure analysis case study is presented for a two-piece aerosol containing tetrafluoroethane, commonly referred to as Refrigerant 134a. A gentleman was preparing to recharge the air conditioning system of an automobile when the bottom exploded off the aerosol container, propelling the body of the aerosol container like a rocket, which hit the man in the eye and blinded him in that eye. The aerosol was never connected to the air conditioner, therefore backpressure from the air conditioner (AC) compressor was ruled out as a cause for the explosion. The objective of the study was to determine why the aerosol exploded. Several recently developed test methods were used, including two types of heat-to-burst tests and a puncture chamber to measure the pressure-versus-temperature behavior of aerosols. More common test methods were also used, such as water bath pressure tests, hydro pressure burst tests, pneumatic pressure burst tests, hardness measurements, weight measurements, metallography, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and an accident scenario recreation. A semi-empirical correlation between the hardness and weights of the container bottoms was used to determine the explosion temperature and/or pressure. This semi-empirical correlation agrees in principle with an analysis of the explosion pressures using finite-element analysis (FEA). The root cause for the explosion was determined to be a lack of strength of the bottom of the two-piece aerosol coupled with heating the aerosol to temperatures significantly above room temperature.  相似文献   
113.
This study examined organizational family-responsive policies, perceptions of the organization as family supportive, and supervisor support as issues that may be salient to the experience of conflict between paid employment (work) and family roles. Data were collected from 355 managerial personnel in New Zealand. Although work-family conflict and psychological strain were strongly linked, the availability of organizational policies had no significant association with levels of conflict or strain, whereas policy usage was related only to work-to-family interference and not to family-to-work interference. On the other hand, perceptions of the organization as family supportive and supervisor support for work-family balance displayed significant relationships with key variables, highlighting the importance of these variables for interventions designed to ameliorate the negative impact of work-family conflict on managerial well-being. Implications for the effective implementation of family-responsive interventions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
114.
煤粉粒度对高炉风口前燃烧性能的影响   总被引:9,自引:2,他引:7  
马政峰  吴铿  左兵  宋建成  魏欣  窦庆和  魏群 《钢铁》2003,38(7):35-38
安钢炼铁厂在喷吹瘦煤后,将小于0.074mm的比例由70%放宽到30%,使磨煤能力提高了21%。采用自行设计的风口取样器,研究了风口前气体成分和煤粉燃烧率的变化。当煤粉粒度变粗后,风口前循环区变长,放宽煤粉粒度与高富氧、高风温配合,能使高炉得到较好的经济效益。  相似文献   
115.
通过例句讲解了until的用法,辨析了until与till、before的异同,并列举了高中英语和大学英语部分课文及习题中的例句。  相似文献   
116.
钕电解阳极过电位的测定   总被引:2,自引:0,他引:2  
用慢扫描示波法测定了钕电解的阳极过电位 .考察了温度、阳极电流密度、Nd2 O3添加量、电解质组成等因素对阳极过电位的影响 ,探讨了降低阳极过电位的可能途径 .结果表明 ,阳极过电位随阳极电流密度的增加而增大 ,随温度的升高而减小 ,一定范围内 ,阳极过电位与阳极电流密度的对数呈线性关系 ,满足塔菲尔方程 ;电解质中LiF和Nd2 O3浓度增加 ,阳极过电位降低 ;适当控制阳极电流密度、升高温度、增加电解质中LiF和Nd2 O3的浓度并尽可能减小极间距 ,均有利于降低阳极过电位  相似文献   
117.
遗传算法的改进及其在电力系统无功优化中的应用   总被引:1,自引:0,他引:1  
针对无功优化的动态、多目标、多约束以及非线性特点,提出了基于简单遗传算法的改进算法,在简单遗传算法的基础上,添加了自适应控制和适应度排序思想,并对算法终止准则进行了改进。以IEEE14节点标准测试系统为例对该算法进行了有效性验证。仿真结果表明,该方法对电力系统的无功优化效果良好。  相似文献   
118.
The main purpose of the study reported here was to investigate the relative importance of complexity of syllable structure and task differences in measuring phonological awareness in low-literacy adults. This study is a replication of a study with children conducted by S. A. Stahl and B. A. Murray (1994). Results indicated that the complexity of syllable structure did indeed better describe the construct of phonological awareness in low-literacy adults. At the same time, the authors also found some differences in the pattern of literacy acquisition for their Spanish adults in comparison with child literacy acquisition in English. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
119.
Fluorapatite/hydroxyapatite solid solution has better biological properties than other apatites, especially used as films or coatings. In this work, sol-gel preparation and in vitro behavior of fluorapatite/hydroxyapatite solid solution films on titanium alloy were investigated. Ca(NO3)2-4H20 and PO(OH)x(OEt)3-x were selected as precursors, and hexafluorophosphoric acid (HPFo) was used as a fluorine containing reagent. The Ca and P precursors were mixed with HPFo to keep the Ca/P molar ratio 1.67. The mixtures refluxed for 12 h were used as dipping sols for the preparation of the films. The phase of the films obtained at 600℃ was apatite. The F contents in the films increased with the concentrations of HPF6 in the dipping sols. The solid solution films were shown to have better stability than hydroxyapatite films, and a reasonably good bioactivity in the in vitro evaluation.  相似文献   
120.
尖晶石型软磁铁氧体纳米材料的制备研究进展   总被引:11,自引:0,他引:11  
介绍了软磁铁氧体纳米材料的特性,综述了近年来具有尖晶石结构的软磁铁氧体纳米材料的制备方法。其中包括:化学共沉淀法,水热法,溶胶-凝胶法,喷雾热解法,微乳液法,相转化法,超临界法,冲击波合成法,微波场下湿法合成,爆炸法,高能球磨法,自蔓延高温合成法等。详细介绍了各种制备方法的特点,研究进展及其发展趋势。  相似文献   
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