磨削模架产生的问题及解决方法

导柱、导套属于模架的配合件,其加工的尺寸精度和形位精度要求很高,零件之间要相互配合.针对磨削导柱、导套出现的问题提出一些解决方法,从而提高了加工效率,保证了导柱、导套的配合精度.     

曝气沉砂池的除砂性能研究

对南方某污水厂曝气除砂系统的处理性能进行了研究。结果显示:1进水含砂、砂斗沉砂和砂水分离器出砂的粒径级配差异明显,曝气沉砂池对粒径0.15 mm的砂粒去除率较高;2砂粒在曝气沉砂池底的分布并不均匀,大部分砂粒沉降于池底后半段,其中粒径为0.1~0.2 mm的砂粒主要分布于池底中间位置,而粒径为0.2~0.6 mm的砂粒主要分布于池底后端,砂粒的沉降并不完全符合自由沉淀理论;3曝气不利于砂粒的沉降,曝气强度对除砂率的影响存在最佳值,该曝气沉砂池的最佳曝气量范围为100~150 m3/h;4曝气量一定的情况下,水平流速对除砂率的影响要大于停留时间的影响。     

广西那比水电站环境敏感问题分析及防治措施

通过全面了解那比水电站工程概况及项目区环境概况,对本工程建设的主要环境敏感问题,包括工程建设对河流水文情势的影响、那比水电站库区渭寒沟金矿对库区水质的影响以及工程建设对库区生态环境的影响进行分析,在此基础上提出减免主要环境不利影响的措施,并通过采取有效措施,将项目建设带来的对环境不利的影响降到最低限度,从而为环境所接受。     

URBAN BUILT ENVIRONMENTS,ACCESSIBILITY, AND TRAVEL BEHAVIOR IN A DECLINING URBAN CORE: THE EXTREME CONDITIONS OF DISINVESTMENT AND SUBURBANIZATION IN THE DETROIT REGION

The research explores the impact of socioeconomic and racial variables on accessibility to urban amenities and travel in compact urban built environments that have traditionally been viewed as improving access to daily destinations and promoting nonmotorized travel: urban environments characterized by high densities, mixed land uses, and high connectivity. The study focuses on six neighborhoods in the Detroit region. Two neighborhoods are within the city itself, and predominantly poor and Black, and four of the neighborhoods are in the region surrounding the city, and they are predominantly wealthy and White. This study at the neighborhood scale enables an analysis into how class and race affect accessibility and travel in neighborhoods experiencing urban disinvestment and decline. The research shows that the traditional relationship between high densities, mixed land uses, high connectivity, greater accessibility, and pedestrian activity is significantly weaker in declining inner cities.     

湿法磷酸工业中不锈钢应用综述

分析了湿法磷酸料浆的腐蚀特点,讨论了湿法磷酸工业用不锈钢的选择与应用要求,对当今湿法磷酸工业用不锈钢的特点、应用和发展做了点评.介绍并评定了湿法磷酸工业用主要不锈钢的化学成份、力学性能、耐腐蚀性能和工艺性能,为磷酸设计、设备制造和磷酸生产提供了有意义的参考数据.     

基于AMF-RPC框架的.NET for flash网络应用程序

Flash动态网站已成为"数据驱动的富媒体应用程序"开发的核心,基于AMF-RPC框架的Flash Remoting技术,能够实现完美的.NET for flash网络应用程序。本文主要介绍AMF-RPC技术,以及在这种技术框架下实现asp.net与flash完美结合。     

Effects of Beverages on Alcohol Metabolism: Potential Health Benefits and Harmful Impacts

Nonalcoholic beverages are usually consumed accompanying alcoholic drinks, and their effects on alcohol metabolism are unclear in vivo. In this study, the effects of 20 nonalcoholic beverages on alcohol metabolism and liver injury caused by alcohol were evaluated in mice. Kunming mice were orally fed with alcohol (52%, v/v) and beverages. The concentrations of ethanol and acetaldehyde in blood as well as the activities of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in liver were assessed to indicate alcohol metabolism. The levels of aspartate aminotransferase (AST) and alanine transaminase (ALT) in serum as well as the levels of malonaldehyde (MDA) and superoxide dismutase (SOD) in liver were measured to reflect the alcohol-induced liver injury. The results showed that the treatment of soda water, green tea and honey chrysanthemum tea could accelerate ethanol metabolism and prevent liver injuries caused by alcohol when companied with excessive alcohol drinking. They might be potential dietary supplements for the alleviation of harmful effects from excessive alcohol consumption. On the contrary, some beverages such as fresh orange juice and red bull are not advised to drink when companied with alcohol consumption due to their adverse effects on ethanol induced liver injury.     

涡轮萃取塔在林可霉素萃取中的应用研究

林可霉素是一种高效广谱抗生素,有着广泛的应用。目前在工业生产中,大多采用多级混合澄清槽从发酵液中萃取林可霉素,但混合澄清槽存在占地面积大、溶剂储存量大、操作费用高,操作环境差等问题。涡轮萃取塔是一种高效的萃取塔,有着占地面积小、溶剂储存量低、萃取效率高等优点。在直径50 mm小型涡轮萃取塔中对林可霉素进行了研究:在不同相比、不同转数条件下,研究了林可霉素的传质情况及液滴直径大小分布特征。实验结果表明:在相同流量的情况下,随着转速增高,分散相滞留率随之增高,林可霉素的萃取效果越好。在相同转速、轻相流量不变的情况下,重相流量越低,林可霉素的萃取效果越好。研究结果表明:涡轮萃取塔用于林可霉素的萃取是可行的。     

中国核电的安全与发展

<正>福岛核事故没有改变核电发展的总趋势2011年3月11日13时46分,日本本州岛附近海域发生里氏9.0级特大地震,并引发高达14米的特大海啸,致使日本福岛第一核电站应急柴油发电机不能启动,导致全厂断电,堆芯失去冷却,燃料元件熔化,从而造成大     

The Comparison of Measurement Methods for Air-Kerma Rate in Narrow-Spectrum Series

The air-kerma is one of the most important physical quantities in ionizing radiation dosimetry. The measurement of airkerma rate in narrow-spectrum series is th...