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991.
基于重庆主城区2010-2012年逐日的气象要素和大气环境质量监测数据,对气象条件与空气污染指数(API)进行相关性研究,分析气象条件影响空气质量的机制及协同作用,明确显著影响空气质量的气象要素。结果表明,当天的空气质量与前一天的空气质量相关性非常显著;各气象要素之间存在明显的协同作用,共同影响主城的空气质量;主城空气质量与大部分气象要素之间存在着相关性。其中空气污染指数与降雨、风速的相关性尤为密切。以期本研究成果能为重庆蓝天行动提供技术支持。  相似文献   
992.
随着技术水平提升及生活水平的提高,家电产品的更新换代也越来越快,废旧家电的末端治理问题亟待优化。以北京市为例,运用等维灰数递补动态预测方法研究4类主要家电的销量,发现自2010年起,北京市的家电销售量迅猛增长,并在此基础上预测了2013--2016年废旧家电的产生量,并就规范当前回收体系提出可行一性建议。  相似文献   
993.
张浩 《四川环境》2012,(1):70-75
深入考察水环境质量变化的情况、分析水环境质量变化的规律,需要比较分析水环境质量的变化及与社会经济发展、自然条件的相关性,才能更准确地把握水环境的变化轨迹。对常州市"十一五"期间水环境环境质量变化与社会经济发展及水资源量等指标进行比较和相关性分析。结果表明:"十一五"期间,常州市通过大力开展主要污染物减排,调整产业结构,加强污水集中处理力度等有效措施,主要污染物排放量明显下降,水环境质量明显改善。  相似文献   
994.
With the rapid changes of demographic and socio-economic structure, various ecological and environmental problems have emerged in peri-urban areas. Studies on the correlation between socio-economic development and eco-environmental preservation are inadequate. This paper analyzes the landscape pattern of peri-urban areas to address this issue. First, it studies the differentiation of economic development levels in Beijing peri-urban areas. Then, it explores the correlation between economic development level...  相似文献   
995.
Kar S  Roy K 《Chemosphere》2012,87(4):339-355
Different regulatory agencies in food and drug administration and environmental protection worldwide are employing quantitative structure-activity relationship (QSAR) models to fill the data gaps related with properties of chemicals affecting the environment and human health. Carcinogenicity is a toxicity endpoint of major concern in recent times. Interspecies toxicity correlations may provide a tool for estimating sensitivity towards toxic chemical exposure with known levels of uncertainty for a diversity of wildlife species. In this background, we have developed quantitative interspecies structure-carcinogenicity correlation models for rat and mouse [rodent species according to the Organization for Economic Cooperation and Development (OECD) guidelines] based on the carcinogenic potential of 166 organic chemicals with wide diversity of molecular structures, spanning a large number of chemical classes and biological mechanisms. All the developed models have been assessed according to the OECD principles for the validation of QSAR models. Consensus predictions for carcinogenicity of the individual compounds are presented here for any one species when the data for the other species are available. Informative illustrations of the contributing structural fragments of chemicals which are responsible for specific carcinogenicity endpoints are identified by the developed models. The models have also been used to predict mouse carcinogenicities of 247 organic chemicals (for which rat carcinogenicities are present) and rat carcinogenicities of 150 chemicals (for which mouse carcinogenicities are present). Discriminatory features for rat and mouse carcinogenicity values have also been explored.  相似文献   
996.
A 3D marine seismic survey of the Odoptu license area off northeastern Sakhalin Island, Russia, was conducted by DalMorNefteGeofizika (DMNG) on behalf of Exxon Neftegas Limited and the Sakhalin-1 consortium during mid-August through early September 2001. The key environmental issue identified in an environmental impact assessment was protection of the critically endangered western gray whale (Eschrichtius robustus), which spends the summer–fall open water period feeding off northeast Sakhalin Island in close proximity to the seismic survey area. Seismic mitigation and monitoring guidelines and recommendations were developed and implemented to reduce impacts on the feeding activity of western gray whales. Results of the acoustic monitoring program indicated that the noise monitoring and mitigation program was successful in reducing exposure of feeding western gray whales to seismic noise.  相似文献   
997.
The fact that maternal exposures to some chemicals during pregnancy can adversely affect the structure and function of the nervous system in the offspring is well established. Government agencies have for a long time been concerned with regulation of developmental neurotoxicants and safe perinatal exposures. However, despite this concern, current guidelines provide only broad and nonspecific recommendations and lack clear directions for a model based approach to risk estimation. In this paper we propose a dose-response model for the nonquantal data obtained from developmental neurotoxicological experiments. To account for the critical issue of the correlation among responses from pups in the same litter, the so called intralitter correlation, a hierarchical distributional structure is used to derive the underlying unconditional distribution of responses. The maximum likelihood method is used to estimate model parameters and the covariance matrix of the estimates is derived. An example is used to illustrate the results.  相似文献   
998.
利用土壤元素数据2069448个,鼻咽癌死亡调查资料22560例,研究了鼻咽癌死亡率与土壤环境中61个元素质量分数的相关性。结果表明,汞、铅、硒、针、锡、钛、钽、溴、碘元素质量分数与鼻咽癌死亡率呈非常显著的正相关;铪元素质量分数与鼻咽癌死亡率呈显著的正相关;铟、镱、镥、铀、锆、铋、碲元素质量分数与鼻咽癌死亡率呈较显著的正相关。锰、钠、镁、钙、锶元素质量分数与鼻咽癌死亡率呈非常显著的负相关;钾、钡元素质量分数与鼻咽癌死亡率呈较显著的负相关。钒、铷、铯、银、铝、镓、铊、钪、钇、镧、铈、钕、钆、镝、钬、铒、铥、钼、钨、铁、砷、镉、钴、铬、铜、氟、镍、锌、锂、铍、硼、镨、钐、铕、铽、锗、锑元素质量分数与鼻咽癌死亡率无明显的相关性。  相似文献   
999.
This paper develops a process-convolution approach for space-time modelling. With this approach, a dependent process is constructed by convolving a simple, perhaps independent, process. Since the convolution kernel may evolve over space and time, this approach lends itself to specifying models with non-stationary dependence structure. The model is motivated by an application from oceanography: estimation of the mean temperature field in the North Atlantic Ocean as a function of spatial location and time. The large amount of this data poses some difficulties; hence computational considerations weigh heavily in some modelling aspects. A Bayesian approach is taken here which relies on Markov chain Monte Carlo for exploring the posterior distribution.  相似文献   
1000.
在云南热区营造山桂花、西南桦、马尖相思、高阿丁枫等4种人工林,只要经营得当,对林地土壤理化性质并不造成重大影响,不会引起地力迅速衰退。4种人工林土壤变化的大致趋势是:1993~1995年肥力大多略呈下降趋势,1995~1997年有所上升。  相似文献   
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