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921.
922.
本文从ML3.1级地震震群的活动与矿区的地震地质构造背景出发,结合矿山的开采、抽排水等人为因素,对该地震通过波形对比分析,成因讨论认为:这次地震为诱发构造型矿震。 相似文献
923.
本文根据酵母废液的水质特点,采用了常温升流式厌氧污泥床处理工艺,即温度在26.8-28.0℃,进水COD为7129-9823mg·l^-1时,达到CDO去除率66.0-71.0%,同时,沼气产率为2.4-3.0L·l^-1·d^-1,沼气中烷含量为61.5-69.1%。该法耗能小,沼气可回收,经济效果明显。 相似文献
924.
Wei Luo Yonglong Lu Yan Zhang Wenyou Fu Bin Wang Wentao Jiao Guang Wang Xiaojuan Tong John P. Giesy 《Journal of environmental management》2010,91(12):2599-2607
Concentrations of As and selected metals were determined in surface soils of the Miyun Reservoir watershed of Beijing, China. The degree to which concentrations of As and metals exceeded the corresponding background concentration of soils was: Cr > Cu > Zn > As > Ni with no apparent anthropogenic contamination with Cd and Pb. Based on the results of a combination of multivariate statistics and geostatistical analysis, greater concentrations of Cr and Ni in soils were determined to be primarily from iron ore mining near where the Chaohe River enters the northeast portion of the reservoir. Agricultural activities were responsible for the observed elevated concentrations of Cu and Zn in soils. Relatively great concentrations of As were found in soils near the upstream regions of the Baihe River in Chicheng County where small gold mining activities have taken place. The greatest potential for adverse effects of Cr and Cu occurred along the eastern shore of Miyun Reservoir. 相似文献
925.
Clean processing of copper converter slag to reclaim cobalt and copper could be a challenge. An innovative and environmentally sound approach for recovering valuable metals from such a slag has been developed in the present study. Curing the slag with strong sulphuric acid, without re-smelting or roasting as practiced currently in the industry, render it accessible to leaching, and more than 95% of cobalt and up to 90% of copper was extracted together with iron by water leaching, leaving silica behind in a residue. The copper in the leach liquor was recovered by cementation with iron and the dissolved iron crystallized as ferrous sulphate monohydrate. The cobalt in the mother-liquor rich in iron was recovered by either cementation or sulphide precipitation. Operation variables in the new process were also investigated and optimized. 相似文献
926.
Julie R. Marentette Grace Wang Stephanie Tong Natalie M. Sopinka Matthew D. Taves Marten A. Koops Sigal Balshine 《Behavioral ecology and sociobiology》2011,65(12):2239-2249
Activity levels are modulated by trade-offs between reducing predation risk and the need to move in order to find food or
mates. Because these trade-offs affect males and females differently, many species show sex-specific movement, dispersal patterns,
and spatial navigation capacities, with the sex that gains the most from territory ownership often dispersing less. Unlike
mammals and birds, sex differences in movement among fishes remain poorly studied, and the connections between tests of movement
propensity in the laboratory and in the field are rarely made. Here, we examine the differences in movement between male and
female round goby (Neogobius melanostomus) in both laboratory and field settings. This fish species is invasive in North America and currently undergoing further range
expansions. In the laboratory, round goby males were more active and explored a novel environment more readily than did females.
A large-scale mark–recapture study in Lake Ontario over two years revealed that males moved more than females between years,
but there were no within-year sex differences. Thus, round goby display male-biased movement patterns, providing a comparison
point to dispersal patterns in other taxa. Understanding sex-specific movement of round goby in the field will also help predict
dispersal and population dynamics, both in areas where round goby have already become established and where they are continuing
to invade. 相似文献
927.
Surveys at southwestern China were conducted from November 2004 to July 2005 in three habitat types. A total 3319 individual of 69 bird species were recorded. Although urbanization was presumed to be responsible for decreasing species richness and diversity, our results showed bird species richness, diversity and density in urban habitats were not different in rural habitats. Whereas, the wasteland with low human disturbances, was the lowest bird species richness, diversity and density than others habitats. We inferred habitats structural complexity, large forest patches, native trees and human litter sustain many bird species in campus and park. However, human disturbances, habitats substrate and predation from domestic animals may reduce species richness and diversity. Therefore, we suggested that high vegetative cover should be in urban areas, because it may increase the number of bird species, support larger populations of insectivores, and perhaps create suitable habitat for some ground nesters. Moreover, by recreating or preserving natural islands decreased human disturbance and predation from domestic animals. 相似文献
928.
“一带一路”沿线国家水资源禀赋及开发利用分析 总被引:2,自引:2,他引:0
水资源是基础性的战略资源,开展“一带一路”沿线国家水资源研究对于促进“一带一路”的科学建设具有重要意义。基于世界银行与联合国粮农组织水资源数据库,从水资源开发利用角度入手,分析“一带一路”沿线国家水资源自然禀赋、利用状况,在此基础上进一步分析水资源开发潜力。结果表明:(1)从水资源禀赋来看,“一带一路”沿线国家地表水、地下水和水资源总量均以俄罗斯、中国、东南亚和南亚地区相对较高,中亚、西亚等地区相对较低;人均水资源量则以中东欧、俄罗斯和东南亚地区较高,西亚、南亚地区较低;“一带一路”沿线国家外来水依赖率整体表现为跨境河流下游高,上游及海岛国家低。(2)就水资源利用而言,“一带一路”沿线国家用水量整体呈现“东多西少”的格局,人均用水量表现为“中亚最高,周边较低”的特点;用水结构亚洲国家多以农业用水为主,中东欧国家则多以工业用水为主。(3)水资源开发潜力分析发现,阿拉伯半岛地区各国水资源开发潜力很低,中东欧及东南亚地区水资源开发潜力很高。 相似文献
929.
以全氟辛烷磺酸(PFOS)为目标去除物,选取牛血清蛋白(BSA)为典型蛋白质类有机物,考察了BSA及其浓度,以及BSA与无机离子共存时,离子强度、离子种类对聚酰胺纳滤膜去除水中PFOS的影响.研究发现,原液中存在BSA时,PFOS的去除率有显著提高,而且BSA浓度越高,PFOS的去除率越高;当BSA与无机离子共存时,离子强度越大,PFOS去除率越高.这可能是因为BSA不但会吸附一部分PFOS,还会造成膜污染,BSA浓度越大,膜污染越严重,膜的筛分能力越强,且膜面与PFOS之间的静电排斥力越大,从而提高了PFOS的截留率.而无机离子的存在减小了BSA分子之间及与膜面之间的静电排斥力,使BSA污染层更加厚实,进一步增强了膜的筛分能力.此外,Ca2+提高PFOS去除率的能力优于Na+. 相似文献
930.
Ecosystem service(ES) trade-offs have been broadly recognized and studied over the past decade. However, how to coordinate the relationships among ES trade-offs to achieve win–win outcomes remains a considerable challenge for decision makers. Here, we summarize the current approaches applied to minimize ES trade-offs for win–wins and analyze the trade-offs among different ESs and their drivers. Based on a systematic review of the literature from 2005 to 2018, we identified 170 potentially relevant articles, 47 of which were selected for the review,recording 70 actual or potential trade-offs. Analysis of these case studies showed that trade-off pairs between provisioning services and regulating services/biodiversity accounted for 80% of total pairs. Furthermore, more than half of the ES trade-offs were driven by land use/land cover changes. Harvest and resource demand, natural resource management, and policy instruments were also among the main drivers. Four approaches to coordinate ES trade-offs were identified, including ecosystem, landscape-scale, multi-objective optimization, and policy intervention(and other) approaches. Based on the above, we recommend a rigorous understanding of the roles of different stakeholders, spatial scales of management, trade-off dynamics, and integrated implementation of diverse approaches to coordinate ES trade-offs in order to better achieve win–win outcomes. 相似文献