Prenatal diagnosis of the fragile X using thymidine induction

Eleven pregnancies in ten patients at risk for the fragile X were monitored by amniocentesis or chorion villus biopsy and induction of the fragile site using thymidine, methotrexate and FUdR. Three female fetuses and one male fetus were found to have the fragile X. The results obtained using thymidine induction were superior to those using methotrexate induction and probably better than those obtained using FUdR induction.     

Hydrogen storage and distribution systems

Hydrogen storage and transportation or distribution is closely linked together. Hydrogen can be distributed continuously in pipelines or batch wise by ships, trucks, railway or airplanes. All batch transportation requires a storage system but also pipelines can be used as pressure storage system. Hydrogen exhibits the highest heating value per weight of all chemical fuels. Furthermore, hydrogen is regenerative and environment friendly. There are two reasons why hydrogen is not the major fuel of toady’s energy consumption: First of all, hydrogen is just an energy carrier. And, although it is the most abundant element in the universe, it has to be produced, since on earth it only occurs in the form of water. This implies that we have to pay for this energy, which results in a difficult economic task, because since the industrialization we are used to consuming energy for free. The second difficulty with hydrogen as an energy carrier is the low critical temperature of 33 K, i.e. hydrogen is a gas at room temperature. For mobile and in many cases also for stationary applications the volumetric and gravimetric density of hydrogen in a storage system is crucial. Hydrogen can be stored by six different methods and phenomena: high pressure gas cylinders (up to 800 bar), liquid hydrogen in cryogenic tanks (at 21 K), adsorbed hydrogen on materials with a large specific surface area (at T < 100 K), absorbed on interstitial sites in a host metal (at ambient pressure and temperature), chemically bond in covalent and ionic compounds (at ambient pressure), oxidation of reactive metals e.g. Li, Na, Mg, Al, Zn with water. These metals easily react with water to the corresponding hydroxide and liberate the hydrogen from the water. Finally, the metal hydroxides can be thermally reduced to the metals in a solar furnace.     

火电厂烟气脱硫工艺国产化初探

火电厂排放的SO2形成酸雨已严重危害人类生存环境。国家把解决烟气脱硫问题纳入大政方针之中，强制要求火电厂必须安装烟气脱硫装置。文章介绍了几种目前国际上较为成熟的脱硫工艺，并对各种工艺进行了比较，分析了国内烟气脱硫市场，并就脱硫技术国产化问题提出若干看法。     

单细胞凝胶电泳技术在环境污染物检测中的应用

主要介绍了单细胞凝胶电泳技术(SCGE),包括SCGE的原理、方法及其在环境污染物检测中的应用,该技术可用多种污染物的检测且灵敏度高,具有广阔的应用前景。即SCGE对大气污染物、重金属、醛类及辐射污染的检测,具有高度敏感性,是具有广阔应用前景的新技术。     

紫外—双氧水和亚铁离子体系对硝基苯光降解的研究

研究了以５００Ｗ直管高压汞灯为光源，在双氧水和亚铁离子的体系中，对硝基苯进行光降解的可能性。结果表明，在实验条件下，本系统对硝基苯有明显的降解效果。浓度为５０ｍｇ／Ｌ的硝基苯经过６０ｍｉｎ的光照，其降解率可达９１．７％。此外，还探讨 铁离子浓度、双氧水浓度、硝基苯浓度、ｐＨ值等因素对光降解的影响。     

我国环境信息技术应用回顾与展望

２１世纪人类将全面进入知识经济时代。专家预测 ,到２１世纪中叶主导知识经济社会的仍是信息。在此期间 ,信息系统是资金投入的重点 ,数据转化为信息、信息转化为知识、知识转化为智慧、智慧转化为科学决策 ,信息与知识管理、存储、传递和应用将对决策起着重要的指导作用。面对新世纪知识经济的挑战 ,必须从战略高度来认识并建设我国环境信息系统。１我国环境信息发展历程１ １我国环境信息基础设施建设“七五”期间 ,我国开始环境信息标准化和环境数据库的开发研究。经过十几年的努力 ,国家环境信息化进展较快 ,取得了一定成效。《国家环…     

土壤中嗪草酮迁移和降解的研究

 通过两季马铃薯大田试验，研究了嗪草酮在灌溉沙壤土中的消失和移动情况。结果表明，表层土壤中，嗪草酮施用后最初7～15天内其含量急剧降低，此后随时间推移降低幅度平缓，1993年和1994年试验结束时的残留量分别为5.9μg/kg和2.3μg/kg。两年共采集的379个土样（分布在15～75cm各土层）中只有5个检测到有嗪草酮。1994年大田135cm土层处的水样中，嗪草酮的检测率高达66％，检测浓度范围为0.06～15.85μg/kg，平均浓度为1.94μg/kg。相比较，嗪草酮在大田试验中的消失速率远大于实验室控制条件下的降解速率。     

水泥负载TiO2光催化降解染料水溶液的研究

研究了以ＴｉＯ２为催化剂，且将ＴｉＯ２涂布在模拟工业水处理浅池的水泥质池底表面，以直管高压汞灯为光源，对有机染料酸性玫瑰红Ｂ和晒化绿Ｂ进行光催化降解的可行性。结果表明，在实验条件下，本系统对以上染料有显著的光降解作用，浓度为２５ｍｇ／Ｌ的上述二种染料溶液，经３０ｍｉｎ光照，其降解率分别达８８．２％，此外，还探讨了染料浓度，染料体积、染料溶液ＰＨ值等因素对光降解的影响。     

三峡库区小城镇水环境与工业产业结构优化模型——以万州区分水镇为例

以长江上游三峡库区腹部的重庆市万州区分水镇为研究对象,根据2005年分水镇工业各行业的结构特点及各行业对水环境的污染特点,建立水环境--经济工业结构多目标优化模型,选取工业生产总值最大和COD排放量最小作为优化目标,量化分水镇2010年工业结构,选择出符合当地经济发展"十一五"规划目标和水环境保护目标的工业结构优化方案,提出具体的工业产业发展建议,达到减少工业污染物对境内长江次级河流瀼渡河的污染,有效地改善瀼渡河水质状况,同时保证分水镇社会、经济、水环境的可持续发展的目的.文章同时也对三峡库区小城镇的工业产业结构优化调整,获得既符合经济发展目标又满足水环境保护要求的合理的工业产业结构,提供可借鉴的思路和方法.