超临界流体技术在非均相催化反应中的应用研究

利用超临界流体良好的溶解性能和扩散性能可以很好地解决非均相催化剂的失活问题。介绍了超临界流体的特性及其化学反应的基础理论,进一步探讨了超临界流体技术在非均相催化反应和酶催化反应方面的应用研究,并指出其存在的问题和发展方向。     

Solubility and henry''s law constant for alcohols in water

A new correlation which provides reliable solubility values down to very, very low concentrations is presented for solubility of alcohols in water. The correlation is based on boiling point temperature of the alcohol and can be used for engineering studies involving health, safety and environmental considerations. Results for water solubility and Henry's law constant are provided for a wide variety of alcohols. Representative solubility values (parts per million by weight) are 74,000 for n-butanol (C₄H₁₀O) and 4.0 for 1-dodecanol (C₁₂H₂₆O).     

准直管水射流流动特性的研究

在后混合磨料射流或准直管磨料射流中，为使水射流的动量能够充分传递给磨料，往往需要用准直管同轴套住水射流，以避免因流的侵入。准直管水射流流动特性是影响准直管磨料射流混合和加速磨料效果的主要因素，利用可视化实验和动量守恒原理对准直管水射流的流动特性进行了研究，其结果表明：准直管水射流流动特性状态随压力变化而变化；高压准直管水射流具有扩散流动段、平行流动段和回气流动段；高压准直管水射流的打击力具有沿程损失和出口损失。此外，还推导出了高压准直管水射流打击力的计算公式。     

大气氢氧自由基测量技术研究进展

大气氢氧自由基在对流层大气化学中占有重要地位，但由于其浓度极低而活性极高，所以至今没有合适的测量方法。文章通过总结２０多年来大气氢氧自由基测量技术研究的成果，分析讨论了大气氢氧自由基浓度测量的研究现状和发展趋势。     

高浓度含磷废水治理工艺研究

介绍了"混凝沉淀 砂滤"处理高浓度含磷废水的运行情况及工程治理效果,结果表明:对于磷酸盐(以P计)浓度高达100mg/l的酸洗磷化废水,处理后的出水磷酸盐(以P计)≤0.3mg/l,出水完全可达到v污水综合排放标准tm(GB8978-1996)一级排放标准.     

应用多级模糊模式识别优选轧钢工艺

钢材轧制质量的优劣评价标准之间不存在明显的判定界面和完全准确科学的评价指标。它具有中介过渡性即模糊性的特点。利用多级模糊识别与级别特征值方法对中厚板轧制质量及其相应的轧制工艺制度进行模糊识别与优选 ,其结果与实际工作中的应用情况吻合。     

黄河径流序列标度不变性分析及趋势预测研究

长期以来，影响黄河干流梯级电站可持续发展的因素，除了关键技术因素、经济因素和环境因素，还有对未来径流趋势的认知不足。可见研究黄河干流径流变化趋势，对于黄河干流梯级电站可持续发展具有重要的现实意义。论文利用非趋势的波动分析法，对黄河干流贵德、头道拐和花园口3个水文站径流的标度不变性和未来变化趋势进行了分析和预测。结果显示，3个水文站的径流量将会减少，这将对黄河干流梯级电站可持续发展不利。     

工业污染土壤中Cd的分布特征及化学形态分析

对工业污染地中重金属Cd的分布及存在的化学形态进行了深入系统的研究.结果表明:此类污染土壤在中性条件下,可溶态(水溶态、交换态和有机态)Cd含量较低,分别为0.68%、12.7%和12.4%,不可溶态Cd(颗粒态)约为74.4%.而在偏酸性介质中,可溶态Cd含量较高,约为74.9%,具有明显的可迁移转化倾向.     

Arsenic uptake and transport of Pteris vittata L.as influenced by phosphate and inorganic arsenic species under sand culture

In order to understand the similarity or difference of inorganic As species uptake and transport related to phosphorus in As-hyperaccumulator,uptake and transport of arsenate(As(V))and arsenite(As(III))were studied using Pteris vittata L.under sandculture.Higher concentrations of phosphate were found to inhibit accumulation of arsenate and arsenite in the fronds of P.vittata.The reduction in As accumulation was greater in old fronds than in young fronds,and relatively weak in root and rhizome.Moderateincreases,from 0.05 to 0.3 mmol/L,in phosphate reduced uptake of As(III)more than As(V),while the reverse was observed at highconcentrations of phosphate(1.0 mmol/L).Phosphate apparently reduced As transport and the proportion of As accumulated in frondsof P.vittata when As was supplied as As(V).It may in part be due to competition between phosphorus and As(V)during transport.Incontrast,phosphate had a much smaller effect on As transport when the As was supplied as As(III).Therefore,the results from presentexperiments indicates that a higher concentration of phosphate suppressed As accumulation and transport in P.vittata,especially inthe fronds,when exposed to As(V);but the suppression of phosphate to As transport may be insignificant when P.vittata exposed toAs(III)under sand culture conditions.The finding will help to understand the interaction of P and As during their uptake process in P.vittata.     

关于hyperaccumulator中文译名的探讨

植物修复技术是环境科学与技术的热点和前沿领域,hyperaccumulator作为植物修复技术的核心和及hyperaccumulator内容的文献也增长迅速,但从已发表的文献来看,国内对“hyperaccumulator”的中文翻译很不统一.这种“一词多译”的现象很不利于学术交流.为了规范和统一hyperaccumulator的中文译名,本文从hyperaccumulator的定义和科学内涵探讨其中文译名的准确性.