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101.
学龄儿童肺功能水平影响因素的研究   总被引:1,自引:0,他引:1  
用逐步回归分析方法对与室内、外空气污染和机体状况等有关的因素对广州市学龄儿童肺功能 (FVC、FEV1 、PEFR和 FEF2 5~ 75 )水平的影响进行研究。结果提示 ,影响肺功能水平的主要因素是内因 ,身高的影响最明显 ,呼吸系统疾病或症状发生与肺功能水平下降有关 ;室外空气污染使肺功能水平下降 ,SO2 、NOx 和 PM2 .5 的影响明显 ,PM2 .5 的影响明显大于 PM1 0 和 TSP;居室或厨房通风不良、家庭烹饪用不洁燃料对儿童肺功能的生长不利 ;被动吸烟对女性儿童肺功能有不利影响。对各种影响因素 ,PEFR和 FEF2 5~ 75 比 FVC和 FEV1 更为敏感  相似文献   
102.
Environmental Science and Pollution Research - Sealing layers made of two alkaline paper mill by-products, fly ash and green liquor dregs, were placed on top of 50-year-old sulfide-containing...  相似文献   
103.
Environmental Science and Pollution Research - Microbial fuel cell (MFC) is a sustainable technology to treat cattle manure slurry (CMS) for converting chemical energy to bioelectricity. In this...  相似文献   
104.
105.
The role of the Siberian musk deer in the diets of the Amur tiger, brown bear, and Asian black bear has been studied in the Sikhote-Alin State Biosphere Reserve in 1992 to 2016. Information has been collected from 763 tiger feeding sites, and the contents of tiger feces have been analyzed. Radiotelemetry has been used to evaluate tiger–musk deer relationships. The musk deer accounted for 0.26% of all animal species found to be eaten by the tiger. Musk deer remains in feces of the tiger, brown bear, and Asian black bear occurred with frequencies of 1.3, 0.2, and 0.3%, respectively. A case of musk deer avoiding the presence of brown bear is described.  相似文献   
106.
社会经济和资源禀赋的区域差异导致耕地非农化压力表现出明显的空间异质性。开展耕地非农化压力测算并揭示其时空格局演变,是实现土地资源优化配置的基础。从经济因素、社会因素、产业结构和资源禀赋4个方面构建耕地非农化压力指数评价指标体系,采用熵值法计算各指标权重,继而计算1990~2014年中国31省的耕地非农化压力指数,并在此基础上开展了耕地非农化压力的时空格局分析。结果表明:(1)从空间格局分布来看,中国耕地非农化压力空间分布呈现明显的地理梯度,总体上呈现从东到西依次递减的态势。(2)从时间变化趋势来看,不同地区各省份之间的耕地非农化压力指数变化呈现多元化趋势。东部沿海地区,山东、浙江、江苏的耕地非农化压力指数处于上升阶段,上海、福建的压力指数变化趋势逐渐趋稳,广东的压力指数呈现下降趋势。中部地区,河南、河北、山西、江西的耕地非农化压力指数趋稳,陕西、湖北以及四川、重庆等西南地区省份的压力指数呈上升趋势。西部沿边3省(云南、西藏、新疆)的耕地非农化压力呈现了一致的下降趋势。(3)从时空格局结合来看,耕地非农化压力不同的省份其变化趋势呈现出截然不同的走向。在耕地非农化压力较大的地区,耕地非农化经历了从制度驱动向发展推动的阶段,经济增长的倒"U"型轨迹明显,经济增长与耕地非农化之间的关系逐渐脱钩。在耕地非农化压力居中或较小的地区,产业发展滞后,土地比较收益较低,耕地的社会保障作用、生态作用对耕地非农化的影响较大,从而增加了部分省份的耕地非农化压力。  相似文献   
107.
Data on the ratio of stable carbon isotopes in xylotrophic fungi and their xylic substrates are presented for the first time. It is shown that coniferous substrates are more enriched in the heavy carbon isotope, compared to deciduous substrates. In both cases, however, their carbon isotope composition is characterized by low variability and does not correlate with the species or physiological type of decomposer fungus but shows a statistically significant correlation with the degree of wood mineralization. The ratio of stable carbon isotopes in the fungi depends on that in their substrates but is shifted in favor of the heavier isotope. This trophic shift lacks species specificity, is equally manifested in decomposers of deciduous and coniferous substrates, remains unchanged along the latitudinal climatic gradient, and is positively correlated with the carbon isotope composition of substrates, in the absence of correlation with the degree of their mineralization.  相似文献   
108.
Experiments have been performed to evaluate the impact of weak permanent horizontal magnetic field of about 400 A/m on seed formation in the main magnetic orientation types of radish, the north-south (NS) and west-east (WE) types. The results show that external magnetic field exposure retards plant progression through all stages of ontogeny but does not alter the ratio of NS and WE types. Under its effect, the numbers of pods and seeds and seed weight decrease in the NS-type but increase in the WS-type plants. Therefore, external magnetic field acts as an ecological factor that differentiates the responses of radish plants depending on the type of their magnetic orientation. Differences in the sensitivity of plants to magnetic field exposure are explained by specific features of their physiological status.  相似文献   
109.
Studies in the vicinities of copper smelters and in undisturbed areas of the Middle Urals have been performed to evaluate the effect of industrial pollution with heavy metals on macro- and micromorphological parameters of kidneys (weight, weight index, the spectrum and frequency of histopathologies) in the bank vole (Clethrionomys glareolus Schreber, 1780) and on the accumulation of Cu, Zn, Cd, and Pb in this organ. It has been found that the kidneys of voles from polluted areas accumulate considerable amounts of heavy metals, with their concentrations increasing with age and/or sexual maturation. The kidney weight, index, and the frequency and severity of the majority of observed nephropathies also increase upon change in the reproductive-age status of animals. These parameters show no dependence on the degree of industrial pollution: at individual level, none of the heavy metals accumulated in the kidneys has produced any effect on the frequency and severity of nephropathies. These results contradict the prevailing opinion that toxicants play the determinant role in the development of nephropathies in small mammals inhabiting polluted areas. Therefore, the causes of nephropathies should be sought among other factors, not related to pollution.  相似文献   
110.
Levels and distribution of Dechloranes in sediments of Lake Taihu,China   总被引:1,自引:0,他引:1  
The occurrence and spatial distribution of dechloranes including mirex, dechlorane plus (DP), dechlorane (Dec) 602, Dec 603, and Dec 604 in surficial sediments of Lake Taihu were investigated in this study. The concentrations of mirex and DP ranged from below detection limit (BDL) to 1.29 ng g?1 dw and 0.051 to 2.10 ng g?1 dw, respectively. Dec 602, Dec 603, and Dec 604 on the other hand, were BDL in any of the samples. The contamination levels of DP were higher than that of Mirex at 21 of all 22 sampling sites. Levels of mirex and DP in the lake sediments were correlated when an extremely high mirex value was removed. Both mirex and DP levels were correlated with the amount of organic matters in the sediment samples. Spatial distribution of mirex and DP suggested that these two chemicals in the lake had similar input sources except for one site. Comparison to previously reported flame retardants’ levels in the sediments shows that DP levels were similar with the levels of tetrabromobisphenol A, hexabromocyclododecane but lower than PBDEs and organophosphates levels in Lake Taihu. The higher levels in the north-east part of Lake Taihu adjacent to two major cities: Wuxi and Suzhou, indicated that city effluent might be a major source for DP contamination in the lake.  相似文献   
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