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As an important traditional labor-intensive industry of both India and China, the cocoon silk industry has long made great contributions to the ecological environment protection, rural economic development and the increase in export income of both countries. India is not only a very important cocoon silk trading partner, but an important production competitor of China. In recent years, there has been a large increase in the production and trade of the cocoon silk between China and India; however, China relies heavily on Indian market, which leads to a tendency of further deterioration in the silk trade environment between both countries. The present article makes an empirical study of the cocoon silk resources of the two countries and the scale, product mix and market structure of China-Indian silk trade from 2001 to 2007. Overall silk trading volumes from China to India and market concentration rate are on the increase because of the superiority of Chinese cocoon silk production over that of India. Owing to scattered market share and export that mainly focused on raw materials product, there has been a phenomenon of price reduction and quantity increase. India carries out fierce competition with China in the international market and even imposes antidumping sanction on Chinese silk, which are key factors restricting further increase between China-India trade. Based on the abovementioned facts, the authors aim to put forward suggestions for steadily developing the production and trade of China's silk. 相似文献
444.
Based on shift-share method, this article employs re- gional share, structural shift and competitive shift to analyze the structural benefit and competitive position of agricultural structure in western China by comparing with agriculture, foresting, stockbreeding and fishing before and after Conversion of Farmland to Forest and Grassland (CFFG). Then authors draw following conclusion: while CFFG program has been put in practice, the agricultural structure in western China has some typical characteristics, such as growth faster, structural predominance obvious and more competitive. But the contributiveness from the competition is not too much yet, and the structural benefit of forest estate and stockbreeding are restrained. 相似文献
445.
Incorporating layer- and local-scale heterogeneities in numerical simulation of unsaturated flow and tracer transport 总被引:1,自引:0,他引:1
Feng Pan Ming Ye Jianting Zhu Yu-Shu Wu Bill X. Hu Zhongbo Yu 《Journal of contaminant hydrology》2009,103(3-4):194-205
This study characterizes layer- and local-scale heterogeneities in hydraulic parameters (i.e., matrix permeability and porosity) and investigates the relative effect of layer- and local-scale heterogeneities on the uncertainty assessment of unsaturated flow and tracer transport in the unsaturated zone of Yucca Mountain, USA. The layer-scale heterogeneity is specific to hydrogeologic layers with layerwise properties, while the local-scale heterogeneity refers to the spatial variation of hydraulic properties within a layer. A Monte Carlo method is used to estimate mean, variance, and 5th, and 95th percentiles for the quantities of interest (e.g., matrix saturation and normalized cumulative mass arrival). Model simulations of unsaturated flow are evaluated by comparing the simulated and observed matrix saturations. Local-scale heterogeneity is examined by comparing the results of this study with those of the previous study that only considers layer-scale heterogeneity. We find that local-scale heterogeneity significantly increases predictive uncertainty in the percolation fluxes and tracer plumes, whereas the mean predictions are only slightly affected by the local-scale heterogeneity. The mean travel time of the conservative and reactive tracers to the water table in the early stage increases significantly due to the local-scale heterogeneity, while the influence of local-scale heterogeneity on travel time gradually decreases over time. Layer-scale heterogeneity is more important than local-scale heterogeneity for simulating overall tracer travel time, suggesting that it would be more cost-effective to reduce the layer-scale parameter uncertainty in order to reduce predictive uncertainty in tracer transport. 相似文献
446.
Qiu Cai Mei-Li Long Ming Zhu Qing-Zhen Zhou Ling Zhang Jie Liu 《Environmental pollution (Barking, Essex : 1987)》2009,157(11):3078-3082
Cadmium (Cd) and Lead (Pb) are environmental pollutants. Environmental samples and bovine tissues were collected from the areas around a lead–zinc smelter in Guizhou, China for Cd, Pb, zinc (Zn) and copper (Cu) analysis. Cd in soil (10 mg/kg) and feed (6.6 mg/kg) from the polluted areas was 10 times higher than the Chinese Standards, resulting in higher Cd in bovine kidney (38 mg/kg) and liver (2.5 mg/kg). Pb in feed (132 mg/kg) from the polluted area was much higher than unpolluted areas, causing higher Pb levels in bovine tissues. Environmental Zn was elevated, but bovine tissue Zn was normal. Cu in bovine liver decreased with increased Cd and Pb. Metals in drinking water and in bovine muscle were within the Standard range. Thus, in the areas of this lead–zinc smelter, the environment has been contaminated with Cd and Pb, which has been transferred to cattle through the food chain. 相似文献
447.
Influence of titanium dioxide nanoparticles on speciation and bioavailability of arsenite 总被引:2,自引:0,他引:2
Sun H Zhang X Zhang Z Chen Y Crittenden JC 《Environmental pollution (Barking, Essex : 1987)》2009,157(4):1165-1170
In this study, the influence of the co-existence of TiO2 nanoparticles on the speciation of arsenite [As(III)] was studied by observing its adsorption and valence changing. Moreover, the influence of TiO2 nanoparticles on the bioavailability of As(III) was examined by bioaccumulation test using carp (Cyprinus carpio). The results showed that TiO2 nanoparticles have a significant adsorption capacity for As (III). Equilibrium was established within 30 min, with about 30% of the initial As (III) being adsorbed onto TiO2 nanoparticles. Most of aqueous As (III) was oxidized to As(V) in the presence of TiO2 nanoparticles under sunlight. The carp accumulated considerably more As in the presence of TiO2 nanoparticles than in the absence of TiO2 nanoparticles, and after 25-day exposure, As concentration in carp increased by 44%. Accumulation of As in viscera, gills and muscle of the carp was significantly enhanced by the presence of TiO2 nanoparticles. 相似文献
448.
河北省海岸带土壤盐渍化研究 总被引:3,自引:0,他引:3
孙娟 《中国环境管理干部学院学报》2009,19(2):72-75
在当今土地资源日益短缺的年代,作为一种土地资源,盐渍化土地越来越重要,越来越受到社会的普遍关注。本文通过分层采集土样,对整个河北省海岸带的土壤盐渍化进行了研究,在借鉴国内外先进经验的基础上,提出了土壤盐渍化防治和综合利用应视各国、各地具体情况而定,并指出盐渍土未来的研究趋势应以利用新技术、探寻新的改良方法及与农业生态和环境保护研究密切线合这三个方面为主。 相似文献
449.
污水处理中紫外消毒方法与传统消毒方法相比之下具有不需要投加化学药剂、不产生有毒有害副产物、消毒效率高、操作简单、便于运行管理等特点。本文着重介绍了目前用于消毒的紫外灯的种类,并阐述了浊度、微生物种类、光复活性能等影响紫外消毒效果的因素,最后对未来紫外消毒方法发展的前景做出了分析。 相似文献
450.