中国煤电和核电的环境影响与健康风险比较

将煤电与核电的环境影响和健康风险从全燃料链角度进行比较 ,结果表明 ,煤电燃料链的环境影响和健康风险比核电燃料链大。     

农业资源型技术创新三环模式及链接特性

本文将农业资源系统理论与农业技术创新学的理论与方法相结合,重点阐述了基于科技价值链的农业资源型技术创新三环模式及链接机制.农业资源型技术创新实质上就是以提高各类农业资源利用率为核心的农业技术改造和技术革新.农业资源型技术创新价值链是指从农业技术创新源到科技成果产业化开发的全过程中,由一系列相互独立、相互联系的创新主体链接起来的,使其科技开发价值不断增值的农业资源型技术创新链条集合体.其技术生命有机体在其发育成长的三个阶段形成了由相关功能节点链接而成的三个关键创新环,即研发创新环、孵化创新环和市场创新环,称为农业资源型技术创新三环模式.在农业资源型技术创新过程中,由各功能节点组配链接成链接单元,再由链接单元链接成关键创新环,进而构成三环模式链条集合体系统网络,这一"点→元→环→链→网"的逐级链接过程,表现出定向有序性、无限多样性、互利共生性和价值递增性等创新价值链接的规律性特性.     

Individual risk analysis of high-pressure natural gas pipelines

Transmission pipelines carrying natural gas are not typically within secure industrial sites, but are routed across land out of the ownership of the pipeline company. If the natural gas is accidentally released and ignited, the hazard distance associated with these pipelines to people and property is known to range from under 20 m for a smaller pipeline at lower pressure to up to over 300 m for a larger pipeline at higher pressure. Therefore, pipeline operators and regulators must address the associated public safety issues.This paper focuses on a method to explicitly calculate the individual risk of a transmission pipeline carrying natural gas. The method is based on reasonable accident scenarios for route planning related to the pipeline's proximity to the surrounding buildings. The minimum proximity distances between the pipeline and buildings are based on the rupture of the pipeline, with the distances chosen to correspond to a radiation level of approximately 32 kW/m². In the design criteria for steel pipelines for high-pressure gas transmission (IGE/TD/1), the minimum building proximity distances for rural areas are located between individual risk values of 10⁻⁵ and 10⁻⁶. Therefore, the risk from a natural gas transmission pipeline is low compared with risk at the building separated minimum distance from chemical industries.     

Domestic or imported? An assessment of carbon footprints and sustainability of seafood consumed in Australia

The distance between where food is produced and consumed is increasing, and is often taken as evidence of an unsustainable global food system. Seafood is a highly traded commodity yet seafood sustainability assessments do not typically consider the impacts of the movement of products beyond the fishery or farm. Here we use life cycle assessment to examine the carbon footprint of the production and distribution of select seafood products that are consumed in Australia and determine differences in the sustainability of imports and their domestically produced counterparts. We found that the distance food is transported is not the main determinant of food sustainability. Despite the increased distance between production and consumption, carbon footprints of meals from imported seafood are similar to meals consisting of domestically produced seafood, and sometimes lower, depending on the seafood consumed. In combining LCA with existing seafood sustainability criteria the trade-offs between sustainability targets become more apparent. Carbon ‘footprinting’ is one metric that can be incorporated in assessments of sustainability, thereby demonstrating a broader perspective of the environmental cost of food production and consumption.     

An approach to preimplantation diagnosis of β-thalassaemia

Using the polymerase chain reaction (PCR), it was possible to amplify a single copy fragment of the β-globin gene from 2–32 human embryonic cells obtained from arrested preimplantation embryos. For the detection of β-thalassaemia mutations, allele specific priming of the PCR using nested primers was employed using approximately 10 pg of DN A from individuals known to carry these mutations. This approach was successful in detecting the presence or absence of five Asian Indian β-thalassaemia mutations that were selected for this study. In spite of meticulous precautions against contamination, false-positive amplification was observed, a problem that will have to be overcome before this approach can be used in clinical practice.     

Morphology, composition, and sources of individual aerosol particles at a regional background site of the YRD, China

Aerosol samples were collected at Lin'an, a background site of Yangtze River Delta(YRD).Morphology, size, composition, and mixing state of individual aerosol particles were characterized by transmission electron microscopy(TEM) coupled with energy dispersive X-ray spectroscopy(EDS), and the soluble ions of PM_(1.0) were studied by aerosol mass spectrometer(AMS). The daily average AMS mass concentrations of sulfate, nitrate, and ammonium were about 5.8, 8.6, and 5.6 μg/m~3, respectively. Individual aerosol particles were classified into seven types: S-rich, K-rich, organic matter(OM), soot, fly ash, metal, and mineral. S-rich particles were dominant in all size bins, and 51%(by number) of S-rich particles were internally mixed with other particles. The fraction of organic coating particles was 13.7% in morning, 25.2% in afternoon, and 11% in evening, suggesting that the strong photochemical process during afternoon produced more secondary organic aerosols(SOA) on the surface of inorganic particles. Fly ash and metal particles were abundant during the day, suggesting the influence of emissions from coal-fired power plants and steel plants. The results indicate that the intense industrial emissions in the YRD significantly transported to the background areas. PM_(2.5) concentration may be lower in background air than in urban air but complex mixing state of aerosol particles indicates that the long-range transported particles substantially influenced the background air quality.     

氯化石蜡产品中短链和中链同系物的指纹分布

使用气相色谱-电子捕获负化学电离质谱（GC-ECNI-MS）,对包含CP-42、CP-52和CP-70三种常见氯含量的22个CPs产品进行了测定,分析了不同氯含量的CPs产品中短链氯化石蜡（SCCPs）和中链氯化石蜡（MCCPs）同系物的分布模式.SCCPs同系物呈现5种分布特征,分别是CP-42型、三类CP-52型和CP-70型,MCCPs同系物呈现4种分布特征,分别是CP-42型和三类CP-52型,CP-70产品中MCCPs同系物未呈现出一致的分布规律.CPs生产原料石蜡中烷烃的成分组成和CPs生产工艺的不同,是造成产品同系物分布模式不一致的原因.通过统计学分析,得到CPs产品中SCCPs和MCCPs同系物的指纹分布,这是开展环境中CPs的源解析、迁移转化、归趋和毒性风险评价等研究的有利工具.     

三重属性的承载力约束下中国水资源利用效率动态演进特征分析

基于水资源"资源禀赋-社会经济-生态环境"三重属性约束建立承载力测算模型,创新性地将水资源承载力作为投入要素,构建SFA效率测算模型,运用2003～2017年中国31个省份面板数据,应用Kernel密度估计和Markov链对水资源使用效率的动态演进特征进行分析.结果表明:①中国大部分省份水资源承载力在稳步提升,西北、华北、东北和华中地区呈较低水平,西南、华南等地区呈较高水平;②中国所有省份水资源利用效率均保持稳定增长,西部地区比中、东部地区增长幅度更大,整体呈现东高西低,南高北低的空间态势;③中国水资源利用效率动态演进存在多极化和趋同化现象,部分省份存在梯度效应,同时具有俱乐部收敛特征,流动性差,马太效应凸显.为实现水资源、社会和环境的协调耦合,降低区域间资源使用效率差异,提升水资源利用效率,提出需要充分考虑水资源承载力,统筹全国及区域水资源供需协调发展战略,构建水权交易市场等建议.     

Prenatal diagnosis of NADH:ubiquinone oxidoreductase deficiency

NADH:ubiquinone oxidoreductase (complex I of the mitochondrial respiratory chain) deficiency is a severe disorder with an often early fatal outcome. Prenatal diagnosis for complex I defects currently relies mainly on biochemical assays of complex I in fetal tissues such as chorionic villi (CV), and is only in a minority of cases possible by means of mutational analysis of nuclear-encoded genes of complex I. We report on our experience to date with prenatal diagnosis in pregnancies at risk for complex I deficiency. We measured complex I activity in native CV and/or cultured CV in 23 pregnancies in 15 families. In accordance with the results of the investigations in CV, 15 children were born clinically unaffected. Two prenatally diagnosed unaffected fetuses and two prenatally diagnosed affected fetuses were lost prematurely with spontaneous or provoked abortions, respectively. Two affected children were born (prenatally found to be affected). In two pregnancies a discrepancy between native and cultured cells was found. We conclude that prenatal diagnosis for complex I deficiency can be reliably performed. Pitfalls were encountered in using cultured CV as a result of maternal cell contamination (MCC). Future research on pathogenic nuclear mutations underlying complex I deficiency will extend the possibilities for prenatal diagnosis at the molecular level. Copyright © 2001 John Wiley & Sons, Ltd.     

江淮流域大洪水的因子分析及成因链初步构造

结合 1998年长江流域的特大洪水 ,提出了洪水成因链的概念 ,分析了各个物理因子对江淮洪水的影响。指出影响江淮洪水的物理因子都是层层相接、环环相扣的 ,它们组成了一个互相联系、互为因果的洪水成因链。成因链上物理因子之间的正反馈作用和消长作用 ,导致成因链上各个因子的致洪理论都不能完全地自圆其说 ,因而也无法完全确定地用于洪水预测。只有深入探讨洪水成因链上物理因子之间的正反馈作用和消长作用 ,对它们进行全面综合的诊断分析 ,才能提高江淮洪水预测的准确率。