复杂条件下的大直径泥水盾构掘进参数控制

对盾构掘进参数进行了详细试验,对不同地层条件下刀盘扭矩与刀具磨损情况之间的关系进行了详细分析,并探讨了盾构姿态的控制方法,同时对同步注浆参数及泥水循环系统做以简要介绍,总结了掘进参数、泥浆密度等在盾构掘进中的重要地位。     

某厂常压热水锅炉房的改造

本文分析了常压热水锅炉的优劣,并对某厂的热水锅炉房进行改造。主要通过调整膨胀水箱的位置和重新对热水循环泵选型两方面,将有压锅炉房改造为常压锅炉房。     

Resting Study of Tracer Experiment on Catalytic Wet Oxidation Reactor under Micro-gravity and Earth Gravity Conditions

The International Space Station（ISS） employs catalytic wet oxidation carried out in a Volatile Reactor Assembly （VRA） for water recycling. Previous earth gravity experiments show that the VRA is very effective at removing polar, low molecular weight organics. To compare the reactor performance under micro-gravity and Earth gravity conditions, a tracer study was performed on a space shuttle in 1999 by using 0.2% potassium carbonate as the chemical tracer. In this paper, the experimental data were analyzed and it is indicated that the reactor can be considered as a plug flow one under both micro-gravity and earth gravity experimental conditions. It has also been proved that dispersion is not important in the VRA reactor under the experimental conditions. Tracer retardation was observed in the experiments and it is most likely caused by catalyst adsorption. It is concluded that the following reasons may also have influence on the retardation of mean residence time ： （1） the liquid can be held by appurtenances, which will retard the mean residence time; （2） the pores can hold the tracer, which can also retard the mean residence time.     

Oxygen isotope variation in the water cycle of the Yamzho lake Basin in southern Tibetan Plateau

Given the potential use of stable isotope in the paleoclimate reconstruction from lacustrine records as well as in the local hydrology cycle, it is crucial to understand the processes of stable isotope evolution in catchment in the Tibetan Plateau region. Here we present a detailed study on the water oxygen isotope based on 2 years observation including precipitation, river water and lake water in the Yamzho Lake, south of the Tibetan Plateau. Temporal variation of local precipitation 5180 shows an apparent ＂monsoon cycle＂. In monsoon season, 5180 in waters is lower. In non-monsoon season, δ^18O in precipitation and lake water is higher and higher river δ^18O exists in spring, probably reflecting the effect of land surface evaporation, together with the higher δ^18O values in spring precipitation. It is also found that the surface lake water δ^18O varies seasonally and annually. The lower lake water δ^18O in the late summer is apparently related to the summer monsoon precipitation. The mean δ^18O value of lake water in 2007 is 1.2‰ higher than that in 2004, probably due to the less monsoon precipitation in summer of 2007, as can be confirmed from the precipitation data at the Langkazi meteorological data. It is also found that an obvious shift of vertical lake water δ^18O reflects the fast mixture of lake water. δ^18O values of lake water are over 10‰ higher than those of precipitation and river water in this region due to the evaporation fractionation. The modeled results show that the evaporation process of the lake water is sensitive to relative humidity, and the present lake water δ^18O reflects a relative humidity of 51% in the Yamzho Lake. It shows that the lake will take 30.5 years to reach present lake water δ^18O given a large shift in the input water δ^18O. The modeled results also reveal that surface lake water temperature and inflow δ^18O have slight effect on the isotopic balance process of lake water in the Yamzho Lake.     

西南喀斯特峰丛山区雨水资源有效利用

雨水资源是总水资源,地表水和地下水是其派生资源.雨水资源利用是水资源的直接利用,是减少蒸发和渗漏等水量损失的有效利用.西南喀斯特峰丛山区是湿润气候区内的特殊干旱缺水区,该区的水循环和水资源过程有别于非喀斯特区,水资源利用开采应按其水循环规律和水资源过程,采用不同利用模式及其系统组合,提高雨水资源直接利用率,缓解干旱缺水程度.     

新疆气候转型及其对全球变化的影响

随着全球变暖趋势的发展，新疆气候也发生着相应转变，主要表现在：气温上升；降水增加；冰川消融；河川径流增加；湖泊水位上升，面积扩大；洪水灾害频繁；沙土暴天气减少；土壤盐渍化趋势加重等。气候转型的原因可能是，空气中水汽增加和有利的天气形势；全球显变暖驱动水循环加快。     

基于热流固耦合的热水循环泵转子强度分析

基于Workbench平台,采用热-流-固耦合方法对热水循环泵内的转子系统施加温度和压力载荷进行计算,得到基圆直径D3=214 mm、D3=216 mm和D3=218 mm下转子系统的热流密度及等效应力的分布,讨论了不同蜗壳基圆直径对转子系统结构强度的影响规律,同时对转子系统进行模态分析.研究结果表明,泵轴与轮毂配合段的配合面以及叶轮螺母与叶轮的配合面上出现了热流密度最大值;基圆直径的改变对叶轮螺母上的热流密度以及最大等效应力影响很小;转子系统在第三阶模态下由轴线沿径向振动,最大变形出现在距中心轴线最远的叶轮外缘.     

质量与发展循环经济之实践

金东纸业〈江苏〉股份有限公司在十几年的经济发展过程中,注重发展循环经济,把走循环经济之路视为企业生存之本、发展之本,探索质量与循环经济发展之路。金东的实践告诉世人造纸企业完全可实现经济效益、社会效益、环境效益同步发展,且相互促进、取得共赢     

基于ARM的电热水循环采暖器控制系统设计

文章介绍一种实用的水循环电热采暖器的组成及其控制系统的软、硬件设计方法.该系统采用纳米材料加热体,利用ARM控制对水温、水位、房间温度等参数的检测,并进行超温、缺水、漏电等保护,提高了系统的可靠性.     

通过水循环控制饮用水中亚硝酸盐的研究

以含有亚硝酸盐的自来水为研究对象,稳压泵为动力对水样进行水循环处理,考察循环水和静置水中亚硝酸盐的变化.实验结果表明,循环自来水与静置自来水中亚硝酸盐的质量浓度差值随着时间延长而增加,循环360 h后循环水中亚硝酸盐质量浓度为静置水质量浓度的112%.循环水的亚硝酸盐和硝酸盐之间存在着显著负线性相关性.另外,净水器出水后的循环水和静置水中亚硝酸盐的质量浓度均会增加,但循环水中亚硝酸盐增加量小于静置水中亚硝酸盐增加量,且质量浓度控制在002 mg/L以下.因此,将水循环应用到净水器中可解决出水中存在的亚硝酸盐含量超标的问题,提高水质安全,具有广阔的应用前景.