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171.
日本于2001年4月1日生效的一项新法规规定,从国外进口不在所列名单中的转基因产品被视为非法。日本政府开始对进口货物进行检测,以确保其中不含不在名单中的转基因产品,如果含有且在目前阶段可以被检测出来,则必须对其进行标识。日本政府已批准了37种通过生物技术生产出来的产品。  相似文献   
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The need for cross-disciplinary scientific inquiries that facilitate improved natural resource management outcomes through increased understanding of both the biophysical and human dimensions of management issues has been widely recognized. Despite this broad recognition, a number of obstacles and barriers still sometimes challenge the successful implementation of cross-disciplinary approaches. Improving understanding of these challenges and barriers will help address them and thereby foster appropriate and effective utilization of cross-disciplinary approaches to solve natural resource management challenges. This research uses a case study analysis of the United States National Estuarine Research Reserve System to improve understanding of the critical factors that influence practitioners’ decisions related to incorporating social science into their natural resource management work. The case study research is analyzed and evaluated within a Theory of Planned Behavior framework to (1) determine and describe the factors that predict practitioners’ intent to incorporate social science into their natural resource related activities and (2) recommend potential strategies for encouraging and enabling cross-disciplinary approaches to natural resource management. The results indicate that National Estuarine Research Reserve practitioners’ decisions related to incorporating social science are primarily influenced by (1) confidence in their own capability to incorporate social science into their work and (2) beliefs about whether the outcomes of incorporating social science into their work would be valuable or beneficial.  相似文献   
174.
A field method is reported for the speciation of arsenic in water samples that is simple, rapid, safe to use beyond laboratory environments, and cost effective. The method utilises solid-phase extraction cartridges (SPE) in series for selective retention of arsenic species, followed by elution and measurement of eluted fractions by inductively coupled plasma mass spectrometry (ICP-MS) for “total” arsenic. The method is suitable for on-site separation and preservation of arsenic species from water. Mean percentage accuracies (n = 25) for synthetic solutions of arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MA), and dimethylarsinic acid (DMA) containing 10 μg l−1 As, were 98, 101, 94, and 105%, respectively. Data are presented to demonstrate the effect of pH and competing anions on the retention of the arsenic species. The cartridges were tested in the UK and Argentina at sites where arsenic was known to be present in surface and groundwaters, respectively, at elevated concentrations and under challenging matrix conditions. In Argentinean groundwater, 4–20% of speciated arsenic was present as MA and 20–73% as AsIII. In UK surface waters, speciated arsenic was measured as 7–49% MA and 12–42% DMA. Comparative data from the field method using SPE cartridges and the laboratory method using liquid chromatography coupled to ICP-MS for all water samples provided a correlation of greater than 0.999 for AsIII and DMA, 0.991 for MA, and 0.982 for AsV (P < 0.01).  相似文献   
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Lee RT  Shaw G  Wadey P  Wang X 《Chemosphere》2001,43(8):1063-1070
Soils initially contaminated with 36Cl in the chloride form were subjected to solid–liquid extractions using a variety of reagents including deionised water and 1 M sodium hydroxide (NaOH). 1 M NaOH was found to result in the greatest recovery of 36Cl from the soils, a result which provided initial evidence that radioactive chlorine became attached to humic substances present naturally within the soils. Deionised water and 1 M NaOH extracts were subjected to analysis involving separation by gel filtration chromatography (GFC). It was found that 36Cl in 1 M NaOH extracts associated preferentially with low molecular weight (LMW) fractions of humic substances whereas, in deionised water extracts, 36Cl appeared to be present exclusively in the chloride form. Previous literature evidence, mainly from highly organic forest soils, suggests that conversion of stable chlorine from chloride to organic forms can occur as a result of biological action. The present paper also presents good evidence for the specific attachment of stable chlorine (37Cl) to a LMW humic fraction, again demonstrated using GFC separation. Current risk assessments of the deep geological disposal of solid radioactive wastes containing 36Cl typically assume a very low degree of sorption based on the notion that the predominant environmental species of radiochlorine is chloride. This paper concludes with a brief discussion on the implications of organochlorine formation in the biosphere for assessment of the radiological impact of deep geological disposal of solid radioactive wastes.  相似文献   
178.
Potent estrogenic hormones are consistently detected in the environment at low concentration, yet these chemicals are strongly sorbed to soil and are labile. The objective of this research was to improve the understanding of the processes of sorption, mobility, and transformation for estrogens in natural soils, and their interaction. Equilibrium and kinetic batch sorption experiments, and a long-term column study were used to study the fate and transport of 17beta-estradiol and its primary metabolite, estrone, in natural soil. Kinetic and equilibrium batch experiments were done using radiolabeled 17beta-estradiol and estrone. At the concentrations used, it appeared that equilibrium sorption for both estrogens was achieved between 5 and 24 h, and that the equilibrium sorption isotherms were linear. The log K(oc) values for 17beta-estradiol (2.94) and estrone (2.99) were consistent with previously reported values. Additionally, it was found that there was rate-limited sorption for both 17beta-estradiol (0.178 h(-1)) and estrone (0.210 h(-1)). An approximately 42 h long, steady-flow, saturated column experiment was used to study the transport of radiolabeled 17beta-estradiol, which was applied in a 5.00 mg L(-1) solution pulse for 44 pore volumes. 17beta-estradiol and estrone were the predominant compounds detected in the effluent. The effluent breakthrough curves were asymmetric and the transport modeling indicated that sorption was rate-limited. Sorption rates and distributions of the estrogens were in agreement between column and batch experiments. This research can provide a better link between the laboratory results and observations in the natural environment.  相似文献   
179.
The degradability of several degradable polymers was examined using three types of degradation environments. These include exposure in a laboratory-scale composting test system containing material representative of the organic fraction of municipal solid waste (MSW), exposure in a thermal hydrolytic environment consisting of water at 60‡C, and exposure in a thermal-oxidative, dry oven environment of 60‡C. The results of the investigation clearly indicate that, in addition to chemical and biological activity which can lead to polymer degradation, physical restructuring and reorganization of the macromolecular structure may also occur at temperatures typically found in a compost environment, resulting in changes in the mechanical properties of the polymer films. In the case of the polyethylene-modified polymers evaluated in this study, all behaved similarly, but differently from the other polymer types. The polyethylene-based films appeared to be susceptible to oxidative degradation and should degrade in a composting environment providing that there is sufficient air in contact with the film for a sufficient period of time. However, when exposed in a laboratory composter, it appears that although ideal temperature-time curves may be obtained, the test time period was insufficient in comparison to the induction period required to achieve the desired thermal oxidative degradation. Issued as NRCC No. 37620.  相似文献   
180.
Book reviews     
Local Politics and Participation in Britain and France

Albert Mabileau, George Moyser, Gerraint Parry, Patrick Quantin. 1989. 281 pp. Price £30.00.

ISBN: 0 521 34576 6.

The Rural State?: Limits to Planning in Rural Society

Paul Cloke and Jo Little. 1990, Oxford University Press. 287 pp.

Price £30.00.

ISBN: 0 19 823287 X

Urbanisation in History: A Process of Dynamic Interactions. International Studies in Demography.

Edited by Ad van der Woude, Jan de Vries, and Akira Hayami. Clarendon Press, Oxford, 1990. 371 pp. Price £40.00.

Housing and Social Inequality

Jenny Morris and Martin Winn

Integrated Land‐Use and Transport Modelling — Decision Chains and Hierarchies

Tomas de la Barra

Beyond Green Belts — Managing Urban Growth in 21st Century

Regional Studies Association (1990). 64 pp. Price £9.95.

Learning from Rotterdam

M. J. Vroom and J. H. A. Meeus.

173 pp. Nichols, New York. Price £25.

Reviewing the Quality of Environmental Statements

N. Lee and R. Colley

EIA Centre, University of Manchester, 1990.

Occasional Paper 25, 46 pp. Price: £3.00.

Knowledge and Public Policy: the search for meaningful indicators

Judith Innes. Transaction Publishers, New Brunswick. 352 pp. Price: £16.95.

Urban Problems: An Applied Urban Analysis

Michael Pacione. Routledge, 1990.

Living with Inner City Policies: Two Essays on Inner City Life and Inner City Policies

Meryl Aldridge and John Edwards, Department of Social Policy, Royal Holloway and Bedford New College. Social Policy Papers No. 2, 1989.

Information Technology in Geography and Planning: including principles of GIS

Bracken and Webster, Routledge, London 1990. 444 pp.

Housing and Social Change in Europe and the USA

Michael Ball, Michael Harloe and Maartje Martens. Routledge, 222 pp. Price: £10.99.

Land and Property Development: Changing Context

Edited by Healey and Nabarro. 212 pp. Price: £39.50.  相似文献   

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