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941.
The SO2 emission sources of the Chengdu-Chongqing economic zone were divided into 556 emissions units according to four different categories, which are city, industry, point sources, and area sources. The CALPUFF model was used to calculate the contribution of each unit, and consequently obtain an influence-transferring matrix. To ensure that the SO2 concentrations of 46 cities and counties in the Chengdu-Chongqing economic zone meet air quality standards, an emission optimization model was developed to calculate optimal emissions of each emission unit under different development scenarios. The result showed the optimal emissions of SO2 by different provinces and industries. To achieve the target of restricting and optimizing development, corresponding planning programs were developed for every district.  相似文献   
942.
柴瑜  李智 《环境科学与管理》2009,34(12):187-189
清洁生产审核是企业实现清洁生产最为有力和高效的工具之一,如今已广泛应用于各行各业。某卷烟厂结合自身清洁生产工作现状,采用清洁生产审核思路和程序,在审核过程中查找生产的薄弱环节,从生产的各个方面系统分析问题及其产生原因,并提出、实施了系列针对性清洁生产方案。该卷烟厂开展清洁生产审核的实践证明,清洁生产审核为企业走可持续发展道路奠定了坚实的基础,是企业实现环境效益和经济效益的双赢必由之路。  相似文献   
943.
The black soil region in Northeast China is an important region for cereal grain production in the country. However, several decades of overexploitation and unsustainable land use practices have caused substantial loss of soil and soil productivity. The dominant soil erosion processes in the black soil region are water, wind and meltwater erosion, of which water erosion on the slope farmland is the major contributor to soil erosion. According to landforms and characteristics of soil and water loss, the black soil region of Northeast China can be classified as the rolling hill area, the low mountain–hill ravine area, and the farming-pastoral area. As a result, land use strategies, including the Three Defense Lines control pattern, the Pyramid Style control pattern, and the control pattern of Minimum Exploiture and Maximal Protection, are proposed for the three respective areas. Moreover, conservation tillage and participatory management are the promising measures that have not been widely implemented in the black soil region until now.  相似文献   
944.
自然遗产地国家公园模式发展的影响因素与空间扩散   总被引:3,自引:0,他引:3  
以自然生态环境保护与公共游憩为基本目标的国家公园模式被视为一种遗产保护和旅游发展融合互促的成熟模式。文章探讨国家公园模式在全球的空间扩散过程及其驱动因素,研究发现:①公益化价值取向是国家公园模式发展的主要动力;②经济发展水平提高反而会造成国家公园供给空间的缩小;③发展中国家与发达国家存在明显差异,环境关注度和旅游发展水平是发达国家的主要影响因素,而发展中国家的国家公园的发育与环境关注度不相关,与旅游发展水平呈负相关;④国家公园模式呈全球扩散趋势,空间重心的转移受国家宏观政治背景、 生态环境保护等因素的影响。  相似文献   
945.
气固再循环半干法烧结机烟气脱硫工艺中几个问题的探讨   总被引:2,自引:2,他引:0  
阐述了烧结机烟气脱硫的必要性,分析了采用的主要脱硫工艺及特点,介绍了气固再循环半干法脱硫工艺(GSCA)及其技术特点。结合邯钢的运行实际,分析了该工艺存在的问题,提出了解决的办法,为该工艺的稳定高效运行提供了参考。  相似文献   
946.
Ecologists increasingly use plot-scale data to inform research and policy related to regional and global environmental change. For soil chemistry research, scaling from the plot to the region is especially difficult due to high spatial variability at all scales. We used a hierarchical Bayesian model of plot-scale soil nutrient pools to predict storage of soil organic carbon (oC), inorganic carbon (iC), total nitrogen (N), and available phosphorus (avP) in a 7962-km2 area including the Phoenix, Arizona, USA, metropolitan area and its desert and agricultural surroundings. The Bayesian approach was compared to a traditional approach that multiplied mean values for urban mesic residential, urban xeric residential, nonresidential urban, agricultural, and desert areas by the aerial coverage of each land-use type. Both approaches suggest that oC, N, and avP are correlated with each other and are higher (in g/m2) in mesic residential and agricultural areas than in deserts or xeric residential areas. In addition to traditional biophysical variables, cultural variables related to impervious surface cover, tree cover, and turfgrass cover were significant in regression models predicting the regional distribution of soil properties. We estimate that 1140 Gg of oC have accumulated in human-dominated soils of this region, but a significant portion of this new C has a very short mean residence time in mesic yards and agricultural soils. For N, we estimate that 130 Gg have accumulated in soils, which explains a significant portion of "missing N" observed in the regional N budget. Predictions for iC differed between the approaches because the Bayesian approach predicted iC as a function of elevation while the traditional approach employed only land use. We suggest that Bayesian scaling enables models that are flexible enough to accommodate the diverse factors controlling soil chemistry in desert, urban, and agricultural ecosystems and, thus, may represent an important tool for ecological scaling that spans land-use types. Urban planners and city managers attempting to reduce C emissions and N pollution should consider ways that landscape choices and impervious surface cover affect city-wide soil C, N, and P storage.  相似文献   
947.
Arsenic (As) contamination of water and soil has become a subject of prime interest due to its direct effect on human health through drinking water and food. In present study two varieties (CSG-8962 and C-235) of chickpea, Cicer arietinum L., which is a major supplementary food in many parts of India and a valuable source of protein, has been selected to estimate the level of arsenate in root and shoot of five day old seedlings vis-à-vis effect of arsenate on seedling growth and induction of thiols including glutathione (GSH) and phytochelatins (PCs) and their homologues. Both varieties accumulated arsenate to similar levels and most of the metalloid was confined to roots, only about 2.5% was translocated to shoot. Plant growth was also not affected significantly in both the varieties. Arsenate exposure significantly induced the levels of thiols including PCs and homophytochelatins (hPCs). The induction of thiols was much higher in roots than shoots and was greater in var C-235 between the two tested ones. Thus, both varieties tolerated and detoxified arsenic through chelation with GSH, PCs and hPCs, primarily in roots, however var C-235 performed better  相似文献   
948.
Benthic marine invertebrates with long-lived larvae are believed to have dispersal capabilities that contribute to maintaining genetic uniformity among populations over large geographical scales. However, both hydrological and biological factors may limit the actual dispersal of such larvae. We studied the population genetic structure of the edible common sea urchin Paracentrotus lividus (Lamarck, 1816), to explore its dispersal patterns in the Atlanto-Mediterranean region and, more specifically, to ascertain the role of the Strait of Gibraltar in shaping the genetic structure of this species. For this purpose, we analysed 158 individuals for the mitochondrial 16S rRNA gene and 151 of these for the nuclear single-copy intron adenine nucleotide transporter (ANT) from 16 localities from the Atlantic and Mediterranean basins, spanning over 4,000 km. Mitochondrial 16S rRNA shows higher genetic diversity in the Mediterranean than in the Atlantic and reveals a sharp break between the populations of both basins, probably as a consequence of the barrier imposed by the Almería–Orán hydrological front, situated east of the Strait of Gibraltar. Both markers suggest that a recent population expansion has taken place in both basins, most probably following the Messinian salinity crisis. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
949.
Bostrychus sinensis is a facultative air breather that inhabits waters of a wide range of salinities. This study aimed to elucidate whether branchial and intestinal osmoregulatory acclimation occurred in B. sinensis transferred from 5‰ water through a progressive increase in salinities to seawater. Our results indicate that B. sinensis acted as a hyperosmotic regulator in 5‰ water, but exhibited hypoosmotic hypoionic regulation in seawater. During short- (1 day) and medium- (10 days) term acclimation to seawater, there were only minor perturbations in plasma osmolality and [Na+], which returned to control levels after 45 days of exposure to seawater. Branchial Na+/K+-ATPase activity was unaffected by 1, 10 or 45 days of exposure to seawater. However, prolonged (45 days) acclimation to seawater led to a significant increase in Na+/K+-ATPase α-subunit protein abundance. Taken together, these results indicate that there could be changes in the expression of Na+/K+-ATPase isoforms and/or post-translational modification of Na+/K+-ATPase in the gills of fish exposed to seawater. Immunofluorescence microscopy revealed that acclimation to seawater for 10 days only resulted in no change in branchial Na+/K+-ATPase protein expression, but there were increases in protein expression of cystic fibrosis transmembrane regulator (CFTR)-like chloride channel and Na+:K+:2Cl cotransporter (NKCC; probably NKCC1). Indeed, NKCC was undetectable in gills of fish kept in 5‰ water by Western blotting, but it became weakly detectable in fish exposed to seawater for 10 days and prominently expressed in fish exposed to seawater for 45 days. Therefore, our results indicate that branchial CFTR-like chloride channel and NKCC1 were the determining factors in the transition between hyperosmotic regulation and hypoosmotic hypoionic regulation in B. sinensis. Furthermore, the intestine of B. sinensis also served as an important osmoregulatory organ, since there were significant increases in both the activity and protein abundance of intestinal Na+/K+-ATPase in fish acclimated to seawater for 45 days. The effectiveness of branchial and intestinal osmoregulatory acclimation in B. sinensis during seawater acclimation led to only a minor increase in plasma osmolality, and thus resulted in relatively unchanged free amino acid contents in muscle and liver.  相似文献   
950.
In this article, we show how a disease could bias stable isotope analyzes of trophic networks and propose a strategy in the choice of tissues to be analyzed. In the past few years, a new pathology (brown muscle disease or BMD) affecting the posterior adductor muscle of Ruditapes philippinarum has emerged in Arcachon Bay. BMD induces a necrosis of muscle tissues which become infused by conchiolin and hence calcified. As muscle of mollusks are often used for trophic food webs studies through stable isotopic analyzes, this work investigated the effect of BMD on carbon and nitrogen isotopic ratios of anterior and posterior adductor muscles of clams collected in February and August 2007. Infected clams displayed a lower condition index and a posterior adductor muscle δ13C enrichment of 1.2‰ in February and 0.7‰ in August. δ15N of posterior muscles was however not affected by the disease. Anterior muscle of diseased clams remained healthy and displayed the same isotopic signature as both posterior and anterior muscular tissues of healthy clam. Acidification significantly depleted δ13C in posterior muscles of infected clams, suggesting calcification, contrary to anterior muscles of infected clam and to both muscles of healthy clams, where no effect was observed. An X-ray diffractometry analysis confirmed the presence of CaCO3 (aragonite). Trophic food web studies relying on stable isotope ratios should utilize only healthy animals or anterior adductor muscles when expertise in mollusk pathology is lacking.  相似文献   
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