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The nitrogen cycle,scientific uncertainty and policy relevant science

science China(Life sciences) 2005年第Z2期48卷 807-817页

作者： David Norse Department of Geography University College London WCIH OBTUK

Much of the research on the nitrogen cycle aims to improving scientific understanding but is not focused specifically on removing or reducing the scientific uncertainties that constrain policy makers in the formulation of appropriate responses to old or emerging environmental problems. Policy makers, for example, commonly find it difficult to assess the spatial or temporal importance of the various risks to human and ecosystem health that stem from man's interference with the natural N cycle. This paper will justify this conclusion by reference to the findings of a recent study on non-point pollution from crop production in China. The findings concern the perceived risks of groundwater nitrate to human health; uncertainties about critical NOx levels and their interactions with other pollutants; various other dimensions of man's impact on the N cycle. The paper will go on to suggest a more systematic process or pathway by which scientists can select and design their research in a manner that could give more effective support to policy makers.

关键词： Policy relevant science, non-point pollution in China, scientific uncertainty and research design.

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science, the Environment and Aquaculture

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Bulletin of the Chinese Academy of sciences 2002年第2期16卷 106-109页

作者： Liu Jian(Bureau of science and Technology for Resources and Environment,CAS) Bureau of science and Technology for Resources and Environment CAS

This paper first analyzes the problems of natural resources, the environment and agriculture in China. Secondly, it discusses the challenge of sustaining a healthy aquaculture. Thirdly, the role of science and technology in environmental management is described in detail, explaining the interaction between research and implication for govemment policymaking and local authority implementation. Finally, the institutes of the Chinese Academy of sciences (CAS) concerned with studies of aquatic ecosystem management are introduced as examples.

关键词： science, the environment and aquaculture

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THE SPACE APPLICATION ACHIEVEMENTS OF THE CHINESE UNMANNED SPACECRAFT "SZ-3"

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空间科学学报 2002年第Z1期22卷 166-176页

作者： SUN Huixian Center for Space science and Applied Research The Chinese Academy of Sciences Beijing 100080 P.R. China

During the 3rd mission of Chinese Unmanned Spacecraft the application sys tem of "SZ-3" (Shenzhou, a divine ship) gets a great success, all its goals are achieved. Many areas of science and breakthrough technology, including earth observation, earth environment monitoring, space material, space life science etc., are carried out in the mission. There are 44 payload instruments *** the instruments are working well during the orbit flight and a lot of good results are obtained. Many areas, for example the moderate resolution imag ing spectroradiometer, the solar ultraviolet spectral irradiance monitor and the space protein crystallization facility perform better than required and expected.A brief introduction of the experiments and the achievements of the mission is given in this paper.

关键词： CMODIS, Space life science, Earth observation, Space material,Earth environment monitoring, Space environment monitoring

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Packing and film thickness theories for the mix design of high-performance concrete

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2016年第10期17卷 759-781页

作者： Pui-Lam NG Albert Kwok-Hung KWAN Leo Gu LI Department of Civil Engineering The University of Hong Kong Pokfulam Hong Kong China Faculty of Civil Engmeering Vilnius Gediminas Technical University Vilnius Lithuania Schoo of Cicil and Transportation Engmeering Guangdong University of Technology Guangzhou 510006 China

A high-performance concrete （HPC） is required to have superior performance in various aspects such as workability,strength, durability, dimensional stability, segregation stability, and passing ability. The mix design of HPC is rather complicatedbecause the number of ingredients in HPC is usually more than those in conventional concrete and some of the required propertiesare conflicting with each other in the sense that improvement in one property would at the same time cause impairment of anotherproperty. However, there is still lack of understanding regarding how the various mix parameters should be optimised forachieving best overall performance. Most practitioners are still conducting mix design primarily through trial concrete mixing,which is laborious, ineffective, and often unable to timely respond to fluctuations in the properties of raw materials. To addressthese issues, the authors have been developing the packing and film thickness theories of concrete materials, in order to revamp themix design philosophy of HPC in terms of the water film thickness （WFT）, paste film thickness （PFT）, and mortar film thickness（MFT） in the concrete. Based on the findings from an extensive experimental programme, suitable ranges ofWFT, PFT, and MFThave been recommended.

关键词： Concrete mix design, Concrete science, Film thickness, High-performance concrete, Packing density, Sustainability

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