长江中游城市群太阳辐射长期变化特征及其与气象要素的关系研究

基于长江中游5个气象辐射站点1961年以来的每日太阳辐射成分及其他气象观测数据,应用线性回归、相关分析、Pettitt突变检验等方法,探讨了近半世纪以来长江中游城市群太阳辐射的变化特征,指明地面接收太阳辐射的突变年份,并分析了太阳辐射与相关气象要素的关系。结果表明:近53年来长江中游地面接收太阳总辐射呈现先下降("变暗")、后上升("变亮")的趋势,该区域的辐射变化与全球范围内的"变暗"及"变亮"的变化趋势是一致的。日照时数与太阳辐射呈现较为显著的正相关性,相关系数r为0.63;而降水量则与太阳辐射呈现负相关性,相关系数r为–0.41。太阳辐射的这种突变变化也直接导致了气温的变化,在"变暗"阶段,太阳辐射与最高气温、气温日较差呈现出显著的正相关性,相关系数分别达到0.61和0.82,但其与最低气温、平均气温的相关性则不显著;在"变亮"阶段,太阳辐射与最高气温、气温日较差、平均气温呈现出正相关性,相关系数分别为0.56、0.62以及0.46,但其与最低气温的相关性则不显著。     

城市景观格局与大气颗粒物污染的关系研究

随着城市化和工业化发展,大气颗粒物对城市空气环境造成了严重污染,选取西安市作为研究区,分析不同时间和空间尺度下城市景观格局与大气颗粒物污染的关系。通过GIS软件、Fragstats4.2软件和SPSS软件对西安市2014年土地利用数据和2014年整年的大气颗粒物监测数据进行分析,结果显示,西安市土地利用类型分布较为集中;西安市大气颗粒物浓度的空间分布特征为浓度从市中心至城郊呈梯度递减趋势,在整体上呈现西北高于东南的倾向,大气颗粒物污染物浓度峰值基本都集中出现在建设用地范围内(PM10:102.7μg/m^3;PM2.5:99.7μg/m^3);相关性结果证实了城市景观格局与大气颗粒物浓度的空间分布特征。研究结果为中国西部内陆城市大气颗粒物污染控制、土地利用规划以及生态建设提供参考。     

重庆市主城区气象要素与空气质量相关性研究

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。     

“十一五”期间常州市水环境质量变化关联分析

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。     

Correlation Between Economic Development Level and Landscape Pattern in Beijing Peri-urban Areas

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...     

First report on development of quantitative interspecies structure-carcinogenicity relationship models and exploring discriminatory features for rodent carcinogenicity of diverse organic chemicals using OECD guidelines

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.     

Dose-response modeling for developmental neurotoxicity data

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.     

鼻咽癌与土壤环境中化学元素的相关性研究

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。     

A process-convolution approach to modelling temperatures in the North Atlantic Ocean

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.     

海河干流表层沉积物总磷、总铁和有机质的含量及相关性分析

采用深水表层沉积物采样器采集海河干流8个断面的表层沉积物,测定不同粒径表层沉积物的总磷(TP)、总铁(TFe)和有机质(OM)含量,并采用多元线性回归分析方法对TP与TFe和OM含量进行相关性分析.结果表明:海河干流表层沉积物的颗粒组成除光华桥断面分布较均匀外,其余各断面主要以砂粒(>54%)为主;沉积物的TP含量为29.00～78.99 μmol/g,TFe含量为595.67～719.91 μmol/g,w(OM)为3.77%～8.79%;同一断面不同粉砂粒之间的TP,TFe和OM含量没有显著性差异(P>0.05),而不同断面之间的差异十分显著(P<0.01).TP与OM和TFe的相关分析结果显示:除金刚桥、外环河桥与中心桥外,其余断面的TP与TFe和OM均具有良好的相关性(R2>0.85).