Prospects for the continued development of environmentally-realistic toxicity test susing microorganisms

The focus of environmental regulations has changed significantly since the introduction of the bioassay as a standard means of assessing environmental impact. Prominent in this change is an increasing emphasis on protecting the integrity of natural ecosystems, which incorporate community- and system-level properties as well as organismal and population processes. Consequently, support for the use of multispecies testing has widened to include not only ecologists in academia but environmental scientists in the regulatory and industrial sector as well. The reason for this trend is clear: the additional environmental realism gained from tests utilizing communities of organisms allows for greater insight into the potential hazard of chemicals and other forms of human activity to natural ecosystems that cannot be obtained from single species tests alone. Many of the problems cited for multispecies testing early in their evolution as a hazard assessment tool have been refuted or overcome. In particular, the u     

某型直升机成品环境鉴定试验工作管理

装备环境适应性的提高有赖于环境工程工作的全面开展,环境工程管理和环境试验是环境工程工作的两大方面。在产品设计定型阶段,通常把环境鉴定试验作为环境质量特性把关的重要手段。以某型直升机新研改型成品为例,通过开展一系列环境工程管理工作,探索出了一套适宜直升机环境鉴定试验管理的方法,规范了试验要求,提升了试验的有效性,保证了该型机环境鉴定试验的权威性,为型号设计定型提供了有力保障,为后续机型的环境工程工作的开展积累了经验。     

武器装备温度冲击试验数值模拟

根据GJB 150．5-86中提供的军用设备温度冲击试验方法,对武器装备和设备做了数值模拟分析。结果表明,由于隔热层的存在,温度冲击对武器装备内部设备的影响非常小,而单独针对设备的温度冲击试验对设备的影响则是非常严酷的。因此,该试验方法对于有隔热层而不会经受急剧的极端温度变化的设备是不适用的。     

不同自然暴露方法对聚丙烯老化的影响

采用直接大气暴露、玻璃板下暴露和百页窗下暴露3种自然暴露方法,研究了聚丙烯塑料外观、力学性能和熔融指数在海南自然暴露过程中的变化,考察了光、热、氧对聚丙烯老化的影响。结果表明：自然环境下,光和热均是引起聚丙烯老化降解的主要因素．并且光的作用更强．氧对聚丙烯老化的影响很小：冲击强度对聚丙烯的老化相当敏感．海南自然暴露9个月时．直接大气暴露的聚丙烯试样冲击强度保持率下降至原始的10％左右。     

直接测量法测试温度稳定性研究

阐述了温度试验中温度稳定的重要性。通过对测试方案、测试设备、测试过程及结果的分析,对如何应用直接测量法测试试验样品非工作状态下温度稳定进行了探索和研究。根据测试结果分析了影响试验样品温度稳定的因素,并指出了直接测量法的优越性。     

异噻唑啉酮的灭藻效应及其生物毒性试验

研究了异噻唑啉酮在海水中的灭藻效应,确定了其对于代表性藻类的浓度-反应关系,并且对其进行了生物毒性试验。根据试验结果采用概率单位法进行数据处理,得出异噻唑啉酮对卤虫无节幼体96 h的半致死浓度(LC50)为10.4 mg／L,并对剂量反应方程进行x2检验,结果表明符合精度要求,计算出的96h-LC50真实可靠。该杀生剂在低浓度下对海洋单细胞藻类有较高的杀灭效应,而且生物毒性较小,是比较适合化学法处理船舶压载水的杀生剂。     

Future use and development of prenatal diagnosis. Consumers' attitudes

The rapid progress of prenatal diagnosis and genetic tests makes it important to investigate attitudes towards this development. A total of 40 women and 20 men with personal experience of prenatal diagnosis for chromosome aberrations were interviewed about their moral opinion of the development. The majority (88 per cent) considered it certain or probable that all new methods developed will also be used in the future. The majority (62 per cent) were hesitant about testing for common disorders, e.g., diabetes mellitus and rheumatoid arthritis, but regarded it justified in some situations. One-third of the individuals (31 per cent) wanted some kind of restrictions for the use of the tests, but only 13 per cent recommended legislation for this purpose. The majority (84 per cent) believed that ethical principles are influenced by scientific progress. In most aspects, the women and their partners had similar attitudes. However, 82 per cent of the women but only 20 per cent of the men considered that the couple itself should decide about prenatal diagnosis. The results demonstrated a considerable respect regarding the difficult choices associated with the development of prenatal diagnosis, also among those who have decided in favour of the test. The study indicated a greater need for autonomy among women than among men.     

碳钢和耐候钢加速腐蚀实验研究

通过对Q235碳钢和09CuPCrNi耐候钢的周期浸润加速腐蚀实验所得到的锈层结构的XRD和拉曼光谱分析表明:γ-Fe2O3、γ-FeOOH和α-FeOOH是构成锈层的主要腐蚀产物.锈层中最终形成的稳定的α-FeOOH腐蚀产物所占比例和分布都将影响耐候钢的耐蚀性能.耐候钢中的Cr可在表面形成致密的氧化膜,同时Cr在缺陷处沉淀析出,可以加速锈层中缺陷的愈合,从而可抵御大气中水气及其有害离子的侵入,防止基体金属进一步腐蚀.因此,增加耐候钢中的Cr的含量将有助于提高耐候钢的耐蚀性能.     

Fetal renal anomalies and genetic syndromes

Renal abnormalities are some of the commonest and most easily detectable anomalies on ultrasound. Many are an isolated finding but the prognosis may be altered considerably by the detection of other anomalies which could indicate a genetic disorder or syndrome. It is often easier to detect presupposed anomalies and the purpose of this article is to introduce and discuss those syndromes that may present with a renal abnormality on ultrasound. Common renal findings are presented with the range of additional anomalies that should be sought and suggested diagnostic tests. It should be remembered that although for many genetic conditions specific mutation analysis is now available, this usually requires pre‒pregnancy investigations. Furthermore, in some cases the definitive diagnosis may not be suspected until post mortem. By this time it may be too late to establish a cell line to confirm the suspicion using laboratory methods. It is therefore important to take tissue samples antenatally where possible, or at delivery, as postnatal samples may have a high culture failure rate. Copyright © 2001 John Wiley & Sons, Ltd.     

河湾路基侵蚀机理与防治措施

着重对河湾路基侵蚀机理进行了理论分析与试验研究。通过对弯道环流的形成，发展特性以及凹岸路基边坡泥沙运动规律及对路基侵蚀试验成果进行分析，发现凹岸路基的侵蚀主要是由河湾水流对路基边坡的淘刷以及路基的崩塌而引起，并提出了各种抵抗河湾路基侵蚀的防治措施。     

硝化抑制剂的加量对生化需氧量值影响的探讨

BOD作为衡量水体受有机污染程度的重要指标,其反映的可生化降解性是其他参数无法替代的。在5日生化培养时间内,硝化作用的耗氧量取决于是否存在足够数量的能进行此种氧化作用的微生物,许多二级生化处理的出水和受污染较久的水体中,往往含有大量硝化微生物,因此测定这种水样时应抑制其硝化反应。通过对特定水体硝化抑制剂添加与否及加量多少对BOD5测定结果的影响,分析并探讨抑制特定水体硝化过程的最佳条件。在严格质量控制的基础上,对特定行业和环境水体的实际样品进行硝化抑制剂添加与否和加量及时间培养曲线等对比实验,通过所得到的比对数据以化学需氧量值与BOD5之间关系为基准,对硝化抑制剂的加量进行了探究。     

Regulating post-implantation fetal sex selection: a UK perspective

This article reviews the current and potential laws relevant to post-implantation fetal social sex selection and considers whether they could provide an effective deterrent and control of the practice, if the United Kingdom decided that such control were desirable. It concludes that enacting, drafting and enforcing of any legislation throws up many difficult practical and ethical issues. These issues need to be debated and further information collected before any legislation is rushed into. Copyright © 2006 John Wiley & Sons, Ltd.     

城镇化、居民生活能源消费与生活碳排放之间关系的实证研究

利用中国1995年－2012年居民生活能源消费数据,通过协整检验、格兰杰因果关系检验等方法对城镇化、居民生活能源消费与碳排放之间关系进行了实证研究,结果发现：城镇化、居民生活能源消费与碳排放存在长期均衡关系;城镇化程度的提高会降低CO2排放;生活能源消费的增加是CO2排放提高的重要原因。居民生活能源消费与CO2排放之间存在着双向格兰杰因果关系。提出稳步推进新型城镇化进程、合理进行生活能源消费、调控城乡居民生活能源消费等建议。     

磁河有机污染物在饱和土壤中迁移转化试验研究

通过静态吸附、静态降解和动态土柱试验,研究了磁河废水中有机污染物在土壤饱水条件下的迁移转化行为.实验结果经线性拟合和参数估算,得到弥散系数D=0.0036m2/d,分配系数K_d=0.19cm3/g,降解系数K=0.68 d-1.表明磁河有机污染物在土壤中有较强的吸附和降解能力.      

全烧垃圾流化床炉飞灰制备免烧砖的性能研究

开展了水泥固化全烧垃圾循环流化床焚烧炉飞灰特性及其制备免烧砖的研究.同时,分析了飞灰的特性,研究了水泥用量对砖体抗压强度和重金属浸出毒性的影响,并对固化前后飞灰在不同p H值溶液环境下的重金属渗滤特性和基于改进RCR连续提取法的重金属形态分布进行了对比研究.结果表明:飞灰中Cd、Cu、Pb、Ni的浸出浓度分别达到1.76、60.29、5.36、1.48 mg·L-1,远超出生活垃圾填埋标准的规定,Cd、Zn、Cu的酸可交换态部分很高,分别为48%、21.26%、20.72%.水泥基材具有良好的稳定效果,添加量达到30%时,免烧砖中重金属的浸出毒性已远低于标准值.随着水泥掺量的提高,免烧砖的抗压强度呈上升趋势,当水泥比例为30%时,强度可达到12.8 MPa,35%水泥比例的砖体,其抗压强度则达到国标建筑用砖的MU15级.与原始飞灰相比,砖体中重金属在不同渗滤液p H下的浸出趋势并未改变,浸出量却显著下降,p H的适应范围变宽.另外,重金属中酸可交换态部分降至低于1%,主要转变成了可还原态,对环境的污染风险大幅降低.     

Coping with the environmental effects of point-source discharges

Current methods for assessing the environmental impact of point source discharges in the United States are reviewed. The emphasis of many assessments of damage from pollution is shifting from chemical or technological standards to biological standards, i.e., the protection of biological integrity in the receiving system. The importance of integrating information from chemical measurements, toxicity tests, and field surveys in impact assessment is re-emphasized. Ways in which environmental professionals can improve methods for assessing damage from pollution and its control are discussed.     

微生物腐蚀监测方法研究进展

近年来,随着石油与天然气资源的大力开发,油气集输管道的腐蚀问题引起了人们的广泛关注,其中微生物腐蚀是导致管线服役失效的一大重要因素.建立快速有效的微生物检测方法及微生物腐蚀监测技术,可对腐蚀状态做出预判,为管道安全运作提供保障.针对这个问题,文中概述了微生物腐蚀机制,详细总结了各类微生物检测方法.从电化学角度出发,系统...