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141.
自然灾害综合区划的基本类别及定量方法 总被引:11,自引:2,他引:9
依据区域灾害系统论原理,提出了以灾害强度、灾害势、抗灾力和灾度4个状态参量描述的区域自然灾害系统状态,建议以之为基础,将自然灾害综合区划分为灾害强度区划、灾害势区划、抗灾力区划和灾度我划4个基本类别、并结合自然灾害综合区划定量方法的讨论,以实例说明了上述基本类别类别划分的可行性。 相似文献
142.
Hiroshi Mitomo Kazunobu Sasada Kenji Nishimura Fumio Yoshii Naotsugu Nagasawa 《Journal of Polymers and the Environment》2004,12(2):95-103
Poly(-caprolactone) (PCL) was blended with diatomaceous earth (diatomite) and irradiated with -rays to introduce cross-linking between PCL molecules or both components. The unwashed diatomite containing a little of a volatile component showed high efficiency of introduction of cross-linking, whereas that with no volatile component showed low efficiency of introduction of cross-linking. Elongational viscosity, melt viscosity, and modulus of PCL/diatomite blend irradiated at various doses were significantly improved. Enzymatic degradation of the PCL/diatomite blend became faster than that of the PCL, though that of the blend irradiated became slower. 相似文献
143.
ABSTRACT: A review of literature pertaining to the relative rates of evaporation from vegetation covered and open water bodies is presented. The review indicates that the only reliable experiments capable of correctly addressing this question are those conducted in situ. Experiments of this nature show the ratio of vegetation covered (swamp) evaporation to open water evaporation to generally be less than unity over extensive surfaces and to only approach unity for vegetation that is young and vigorous. Recent experimental evidence presented within a theoretical context, however, indicates that even in the latter situation the ratio may never reach unity. Consequently, over large lakes and reservoirs, the presence of vegetation may actually be a water conservation mechanism, with the eradication of the vegetation leading to significantly increased evaporative water losses. 相似文献
144.
Differences between scientist and policy-maker response types and times, or the “how” and “when” of action, constrain effective
water resource management in suburbanizing watersheds. Policy-makers are often rushed to find a single policy that can be
applied across an entire, homogeneous, geopolitical region, whereas scientists undertake multiyear research projects to appreciate
the complex interactions occurring within heterogeneous catchments. As a result, watershed management is often practiced with
science and policy out of synch. Meanwhile, development pressures in suburban watersheds create changes in the social and
physical fabric and pose a moving target for science and policy. Recent and anticipated advances in the scientific understanding
of urbanized catchment hydrology and pollutant transport suggest that management should become increasingly sensitive to spatial
heterogeneities in watershed features, such as soil types, terrain slopes, and seasonal watertable profiles. Toward this end,
policy-makers should encourage funding scientific research that characterizes the impacts of these watershed heterogeneities
within a geopolitical zoning and development framework. 相似文献
145.
Milford C. Theobald M. R. Nemitz E. Sutton M. A. 《Water, Air, & Soil Pollution: Focus》2001,1(5-6):167-176
Continuous micrometorological measurements of ammonia (NH3)exchange were made for a period of 19 months (May 1998–November 1999) over intensively managed grassland in southern Scotland. This study focused on the influence of management activities, such as cutting and fertilising, on vegetation-atmosphere exchange of NH3. Measurements were conducted within the European project GRAMINAE (GRassland AMmonia INteractions Across Europe) within which the Scottish site forms one of 6 sites in an E–W transect across Europe. NH3 emissions were enhanced (up to 300 ng m-2 s-1) after cutting followed by larger emissions after fertilising (up to 1400 ng m-2 s-1). Annual budget calculations show the intensive grassland acted as a net source (1.8 kg N ha-1 yr1) although fluxes were bi-directional with deposition dominating in the winter and emission in the summer. Initial modelling of the NH3 exchange using a `canopy compensation point' model has been conducted for key periods. The dynamics of the fluxes during these key periods, such as before and after cutting and fertilising, may be reproduced by introducing different values of the apoplastic ratio, = [NH4
+]/[H+]. 相似文献
146.
《中国现代化报告2007——生态现代化研究》回顾了世界生态现代化的历程,总结了经验,介绍了世界生态现代化的基本原理,分析并评价世界各国生态现代化的水平,进而提出中国生态现代化的战略思考。这个研究报告指出了人类社会发展的方向一一生态现代化,为此我国必须进一步落实科学发展观,加快实施可持续发展战略,充分发挥后发优势,努力实现跨越式发展,走综合生态现代化的道路。 相似文献
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150.
Jolanta Liwkowicz Joanna Kowalska 《International journal of occupational safety and ergonomics》2013,19(1):81-88
Because they cause burns that are difficult to heal, acids are dangerous, and steps should be taken to ensure that the human skin does not come into contact with them. For this purpose safety gloves are generally used by workers who have to handle acids. Such gloves need to be tested to ensure that they are acid resistant. Standard EN 374 (European Committee for Standardization [CEN], 1993c) specifies a method of testing the permeation of liquid chemicals, on a molecular level, through glove material, but it may be difficult to ensure the fitness of the joints of a two-compartment cell, when gloves are lined with jersey. To deal with this a simple pH-meter method to test the permeation of acid and alkali solutions through safety gloves has been developed. The permeation of H2S04, HCI, HN03, and CH3COOH through gloves made from neoprene, nitrile, and PVC was tested. This method seems to be simple and economical. 相似文献