Assessment and management of fetal agenesis of the corpus callosum

Prenatal counselling for fetal agenesis of the corpus callosum is difficult as the prognosis until now has been so uncertain. We have reviewed the current world English literature to provide the best probabilistic information for prospective parents. In total, there are 70 cases where the diagnosis was made prenatally. The diagnosis of apparently isolated agenesis of the corpus callosum (in the absence of other sonographically detectable anomalies) appears to carry an excellent prognosis, with an 85 per cent chance of a normal developmental outcome and a 15 per cent risk of handicap. Fetal karyotyping is recommended as there is a 1 in 10 risk of aneuploidy. If other anomalies are detected prenatally, the outcome is very poor. Termination of pregnancy is advised in these circumstances.     

The application of life cycle assessment to design

This paper explores the practical application of life cycle assessment (LCA) to product system development. While life cycle assessment methods have been studied and demonstrated extensively over the last two decades, their application to product design and development has not been critically addressed. Many organizational and operational factors limit the integration of the three LCA components (inventory analysis, impact assessment and improvement assessment) with product development. Design of the product system can be considered a synthesis of individual decisions and choices made by the design team, which ultimately shape the system's environmental profile. The environmental goal of life cycle design is to minimize the aggregate environmental impacts associated with the product system. Appropriate environmental information must be supplied to decision makers throughout each stage of the development process to achieve this goal. LCA can serve as a source of this information, but informational requirements can vary as the design moves from its conceptual phase, where many design choices are possible, to its detailed design and implementation. Streamlined approaches and other tools, such as design checklists, are essential. The practical use of this tool in product development also depends on the nature and complexity of the product system (e.g. new vs. established), the product development cycle (time-to-market constraints), availability of technical and financial resources, and the design approach (integrated vs. serial). These factors will influence the role and scope of LCA in product development. Effective communication and evaluation of environmental information and the integration of this information with cost, performance, cultural and legal criteria will also be critical to the success of design initiatives based on the life cycle framework. An overview of several of these design initiatives will be presented.     

西江沿岸地带工业资源开发策略

西江沿岸地带是一个工业不发达的待开发民族区域,但它拥有多方面工业资源优势,而且工业开发环境条件良好。作者认为,优势的工业资源开发必须在全方位开放与资源深度利用的基础上以轻型为主导的策略,重点建设制糖、水果加工、水电、有色金属为主的原材料及加工等若干工业基地。布局上以西江干流和区内铁路干线为“轴”,结合重点工业“点”,稳定提高中部,重点开发东部,创造条件开发西部,实现“点轴结合,逐步推进”的工业资源区域开发策略。     

生态农业建设中的水资源生命周期及系统功能响应

论文从生命周期角度，对原先自然环境恶劣、通过生态农业建设取得了良好效果的3个生态农业县的水资源利用进行了全过程研究。结果表明，水资源生命周期过程的进展情况受多种因素影响。目前，各生态农业县水资源生命周期过程仍处在发育的初级阶段。这一过程的完整性与系统生态、经济和社会功能的提高成正比。     

不同生物接触氧化方法对藻类的去除效果比较及其途径分析

比较了3种生物接触氧化法对富营养化水源水中藻类的去除效果，探讨其去除藻类的途径。试验结果表明：淹没式曝气生物陶粒滤池（I型）在4-6m/h过滤速度条件下，对藻类总数的去除效率稳定，平均为70%左右；采用YDT弹性立体填料的中心导流筒曝气生物接触氧化法（Ⅱ型）与直接微孔曝气生物接触氧化法（Ⅲ型），在试验初期对藻类总数的去除率较低，平均去除率分别为60.2%、51.6%。但随着生物膜厚度的增加，试验后期对藻类的去除效果逐步得到提高，平均达70%以上。生物膜对藻类的生物絮凝、吸附、生物膜的脱落沉降等是生物接触氧化法去除藻类的主要途径。     

8级大震的预测研究讨论

两个8级地震的预测在某种程度上被验证了。一个是 2001 年11月14 日昆仑山口西 8.1 级大震,另一个是 2003年9 月27日中蒙俄交界处的7.9 级地震(矩震级为 8级)。基于月球最北直下点的引潮力触发效应和8级大震的三性法分析,我们预测在2005～2008年间,西藏南部和附近地区可能再次发生 8级大震。     

用BaCl2滴定法快速测定硫酸盐的研究

用铬酸钡光度法、EDTA滴定法、间接原予吸收法、离子色谱法等方法测定SO4^2-检测上限都很低（12—200mg／L），且只适用于清洁水，若水样混浊则会引起较大的误差。有的地下水，SO4^2-浓度高迭44000mg／L，用BaCl2滴定法测定SO4^2-：测试水样，以溴酚蓝做酸碱指示剂，加1：50盐酸，调为pH=3．5，加入30ml异丙醇，以钍试荆做终点指示荆，滴加0．01mol／L BaCl2，砖红色为终点，根据BaCl2用量计算SO4^2-浓度。本方法快捷、准确、测定范围大，上限可迭2000mg／L，克服了光度法测定浑浊水样引起误差大的缺点。     

谈双鸭山市气象特征及地形特征对空气质量的影响

双鸭山市采暖期污染较重是因为采暖期燃煤量大、低矮分散的面源多的缘故,同时气象因素及地形特征对空气质量的影响也起着相当大的作用,采用2005年空气质量监测数据,进行双鸭山市气象特征及地形特征对空气质量影响分析,得出空气较稳定的取暖期和具有山风、谷风、局地环流的地形特征是形成双鸭山市空气污染的主要原因之一,并针对地形特征及气象特征对双鸭山市空气质量的影响提出空气污染治理措施.     

阳极溶出伏安法连续测定底泥中的总镉和总铅

底泥样品经盐酸-硝酸-氢氟酸-高氯酸消解后,用1 1盐政溶解残渣,以高氯酸做支持电解质,采用阳极溶出伏安法的标准加入法,连续测定样品中的总镉和总铅.该方法测定土壤标准样品中镉和铅的相对标准偏差分别为5.6%和4.6%,相对误差分别为2.4%和～1.7%;测定自采底泥样品中镉和铅的相对偏差分别为7.7%和8.1%,方法的重复性好;测定土壤标准样品中镉加标回收率为94.0%～106.8%,铅加标回收率为95%～103.8%;自采样品中镉加标回收率为93.0%～105.6%,铅加标回收率为90.0%～105.0%,方法的准确度较高.实验中,镉和铅的半波电位稳定,峰形对称.     

电凝聚过程中消除电极钝化方法的研究进展

电凝聚法是一种对环境二次污染很小的废水处理技术，具有广阔的应用前景。但是,因其电化学过程中可溶性铝或铁阳极的钝化现象而限制了其高效低能耗应用。从电凝聚电极过程的分析入手，讨论了电极钝化的本质原因及消除电极钝化的措施,并介绍了笔者采用自行研制的交变脉冲电凝聚专用电源,彻底消除电极钝化方面的研究进展。