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271.
通过测定液体与废白土粉末之间的接触角及液体与蜡之间的液液界面张力,对水基表面活性剂乳液的溶剂及配方进行了优选,得到最佳的水基面活性剂乳液的组成为:质量分数0.2%的十二烷基苯磺酸钠+体积分数为2.5%的乙醇+体积分数为25%的混合烃(正己烷+苯,等体积)+体积分数为72.5%的水。实验证明,用该水基表面活性剂乳液处理废白土,蜡的回收率可达80%,同时不破坏白土的颗粒结构。  相似文献   
272.
Climatic change and urbanization effect in China during the last 39 years were investigated. It is found that a warming of about 0.23℃ for the annual temperature has been noticed from 1951 to 1989. The warmings of about 0.78 ℃ in winter and 0.34 3℃ in spring have been shown. It is also presented that a cooling of about -0.27℃ in summer has been indicated. The bigger cities are warmer than smaller cities in China. The dried trends in the annual precipitation during the last 39 years were presented. The precipitation decreased obviously in summer all over China. The bigger cities were drier than smaller cities.  相似文献   
273.
Two strains of bacteria were isolated from nitrile polluted soils, and identified as Corynebacterium boffmanii and Arthrobacter flavescens. Acetonitrile, propionitrile, butyronitrile and acrylonitrile were degraded by these bacteria to yield corresponding amides, carboxylic acids and ammonia. The nitrile-degrading abilities of these strains were investigated. The removal rates for the nitrile were nearly 100%, after these bacteria were grown in medium containing 10000 ppm of aceto-, propio-, or butyronitrile at 28 ℃ for 24h. When the reaction mkture consisting of 5000 ppm of above mentioned nitriles or acrylonitrile and 20g (dry cell) /L resting cells of the two strains in 0.06mol/L phosphate buffer (pH7.5) was incubated separately at 25 ℃ with moderate shaking for 15 or 45 min, the nitrile could be degraded completely. The optimum growth conditions for C.hoffmanii and A.flavescens were studied as well.  相似文献   
274.
Climatic changes can be separated into two parts: natural changes -and human activity influenced on climatic changes. The observed data could not only show the effects caused by human activity. Several simulated results as simulated by the GCMs induced by the greenhouse effects in China .have been analysed. It is shown that an obvious warming of about 3-6℃ in winter and 2-5℃ in summer in China as simulated by the GCMs induced by doubling CO2 have been found. There are getting drier or wetter regions in China due to doubled CO2 as simulated by most of models. Comparing the simulated results with the observed data in China, some simulated results are able to be believed. The GCMs should be improved, especially in the regional areas.  相似文献   
275.
利用粉末冶金 /挤压的方法制作了一种新型的Cu C滑动集电材料 ,并对该材料的机械物理、摩擦磨损性能进行了检测 ,结果证明该材料具有较高的抗拉强度、适中的表面硬度、较低的电阻率、优良的摩擦磨损性能 ,是一种较为优良的电力机车滑板材料。其性能测试结果和铁道部标准要求相比 ,优于铁道部标准要求。  相似文献   
276.
半干法喷射烟气脱硫试验研究   总被引:1,自引:0,他引:1  
介绍了半干法喷射烟气脱硫试验 ,研究了钙硫比、雾化水量、进口SO2 浓度、湿度等主要因素对脱硫率的影响规律 ,对布袋除尘器的辅助脱硫也进行了研究。结果将有助于改进半干法脱硫技术 ,并为进一步的工业应用提供了参考数据。  相似文献   
277.
The sunlight photodegradation half-lives of 20 mg/L acetochlor were 151, 154 and 169 days in de-ionized water, river water and paddy water, respectively. When exposed to ultraviolet (UV) light, acetochlor in aqueous solution was rapidly degraded. The half-lives were7.1, 10.1, and 11.5 min in de-ionized water, river water and paddy water, respectively. Photopreduets of acetochlor were identified by gas chromatography/mass spectrometry(GC/MS) and found at least twelve photoproducts resulted from dechlorination with subsequent hydrtrxylation and cyclization processes. The chemical structures of ten photoproducts were presumed on the basis of mass spectrum interpretation and literature data. Photoproducts are identified as 2-ethyl-6-methylaniline; N, N-diethylaniline ; 4, 8-dimethyl-2-oxo- 1,2,3,4- tetrahydroquino-line; 2-oxo-N-(2-ethyl-6-methylphenyl)-N-(ethoxymethyl) acetamide; N-(ethoxymethyl)-2‘-ethyl-6‘-methylformanilide; 1-hydroxyaeetyl-2-ethoxyl-7-ethylind ole; 8-ethyl-l-ethoxymethyl-2-oxo-1, 2, 3, 4-tetrahydroquinoline; 4, 8-dimethyl-l-ethoxymethyl-2-oxo-1, 2, 3, 4-tetrahydroquinoline; 2-hydroxy-2‘-ethyl-6‘-methyl-N-(ethoxymethyl) acetanilide and a compound related to acetochlor. The other two photoproducts were detected by GC/MS although their chemical structure was unknown.  相似文献   
278.
城市户外热环境的舒适性研究   总被引:5,自引:0,他引:5  
介绍了户外热环境舒适性评价的几种方法,提出了户外热环境舒适评价指标OTCD,指出了在室内OTCD能与PMV很好吻合,并且OTCD的各项参数便于测量。  相似文献   
279.
研究不同浓度的Cd对铅锌矿区和非矿区重金属超累积植物——小花南芥真菌根际pH的影响,以便更有效地减轻重金属污染。  相似文献   
280.
北京市二个主要工业区汞污染及其来源的初步研究   总被引:17,自引:2,他引:17  
为了调查北京市汞污染状况及其来源,选择二个主要工业区石景山区和朝阳区为研究对象.共采集表层土壤26个,剖面样品4个,对照土壤样品4个,并且在冬季采集降雪样品和枯叶样品,分析汞含量.结果表明,燃煤烟尘排放的汞是北京市汞的主要来源,汽车尾气和化工厂泄漏可使局部汞含量增高,表层土壤中汞含量为007—275mg/kg.土壤剖面中的汞含量在0—100cm土层中均较高,其含量与土壤有机质和碳酸盐含量正相关.降雪中汞在07—37mg/L之间,明显高于背景值,其中大部分吸附在颗粒物上.枯叶中汞主要是从土壤吸收,并且有可能被雨水淋溶出来.  相似文献   
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