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991.
C.H.D. Magadza 《Environmental monitoring and assessment》2000,61(1):193-205
Climate change impacts on African human settlements arise from a number of climate change-related causes, notably sea level changes, impacts on water resources, extreme weather events, food security, increased health risks from vector home diseases, and temperature-related morbidity in urban environments.Some coastlines and river deltas of Africa have densely populated low-lying areas, which would be affected by a rise in sea level. Other coastal settlements will be subjected to increased coastal erosion. Recent flooding in East Africa highlighted the vulnerability of flood plain settlements and the need to develop adaptive strategies for extreme weather events management and mitigation. In the semi arid and arid zones many settlements are associated with inland drainage water sources. Increases in drought will enhance water supply related vulnerabilities. Inter-basin and international water transfers raise the need for adequate legal frameworks that ensure equity among participating nations.Similarly, water supply and irrigation reservoirs in seasonal river catchments might fail, leading to poor sanitation in urban areas as well as food shortage. Hydroelectric power generation could be restricted in drought periods, and where it is a major contributor to the energy budget, reduced power generation could lead to a multiplicity of other impacts. States are advised to develop other sources of renewable energy.Temperature changes will lead to altered distribution of disease vectors such as mosquitoes, making settlements currently free of vector borne diseases vulnerable. Rapid breeding of the housefly could create a menace associated with enteric disorders, especially in conditions of poor sanitation.The dry savannahs of Africa are projected as possible future food deficit areas. Recurrent crop failures would lead to transmigration into urban areas. Pastoralists are likely to undertake more trans-boundary migrations and probably come into conflict with settled communities.Adaptive measures will involve methods of coastal defences (where applicable), a critical review of the energy sector, both regionally and nationally, a rigorous adherence to city hygiene procedures, an informed agricultural industry that is capable of adapting to changing climate in terms of cropping strategies, and innovations in environment design to maximise human comfort at minimum energy expenditure. In the savannah and arid areas water resource management systems will be needed to optimise water resource use and interstate co-operation where such resources are shared.Climate change issues discussed here raise the need for state support for more research and education in impacts of climate change on human settlements in Africa. 相似文献
992.
993.
灵水湖为岩溶大泉出口形成的水体,具有优良的水质和几乎恒定的水温,但近年来水生生态系统却发生退化,湖底水草几近绝迹。为了寻找退化原因,利用沉积物的有机碳及其同位素、总氮、烧失量、C/N比值环境代用指标,以及~(210)Pb测年来重建过去环境。结果显示,灵水湖沉积物具有稳定的沉积速率(1.769 cm/a),1957~2013年,δ~(13)C_(org)在-29.6‰~-20.3‰之间波动,与TOC有很好的负相关关系,C/N显示有机碳主要来源于内源的湖泊生物;1960至1990年期间,降雨量、气温和湖水最高水位与δ~(13)C_(org)均有一定的对应关系,是此阶段影响有机碳碳同位素的主要因素;而1990至2013年,尽管有机碳主要来源不变,但与降雨量、气温和湖水水位等无明显对应关系,说明影响此阶段有机碳碳同位素的还有人类活动等其它原因。总结该区水生环境演化模型,认为区域尺度的人类活动是导致局部尺度(泉口)环境变化的主要原因。 相似文献
994.
以经典Mincer收入方程为基础。通过引入教育、经验与区域变量。对1990年和2000年我国人力资本收益率及其影响因素进行估计。形成了关于我国人力资本发展阶段特征的基本判断。模型结果支持了正规教育对人力资本的影响由线性向非线性的变化。并且在平均收益率方面中等教育有着潜在优势;在经验因素中。工作前的经验比工作后的经验对收入影响更显重要;东部地区人力资本的形成与其他地区存在显着的差异。而东部以外的地区之间人力资本形成模式差异则不明显。 相似文献
995.
核电厂人因事故预防的定量化决策 总被引:4,自引:4,他引:0
人因事故的分析与预防是核电厂安全运行和管理的重要内容。笔者提出的系统安全性层次分析法主要从两种角度考虑系统的安全性:专家能力权值和安全性矩阵的建立。采用专家判断矩阵确定事故原因对系统安全性的重要度排序。举例某核电厂事故定量分析进行说明,在对事故进行原因分析基础上,构建事故影响因素层次模型,利用层次分析法分析得出事故原因重要度排序由高到低依次为组织管理、操作人员、人机界面、培训与设备状态,并据此提出了相应的预防与改进措施,为安全性要求较高的复杂工业系统提供事故预防的定量化决策依据。 相似文献
996.
Kontoleon Andreas 《中国人口.资源与环境(英文版)》2009,7(2):59-66
Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for development of local communities residing in these reserves. The village ecosystem of Zhuanjinglou Village in Wolong Nature Reserve includes population, farming and livestock (domestic and alpine) and forest ecosystem. An emergy analysis of agro-ecosystem (including the farming and livestock ecosystem) and energy consumption in Zhuanjinglou Village indicates that livestock ecosystem plays an important role in village ecosystem, which may be the source of great pressure on the state of the local environment. The increasing ratio of electricity in energy consumption may play a positive role for environmental conservation. Despite some successful experiences, there are some remaining issues that need to be addressed in the ecological rehabilitation of the village ecosystem. 相似文献
997.
湿地生态系统服务功能评价模式的不足与改进 总被引:2,自引:0,他引:2
本文基于对湿地生态系统服务功能评价研究发展历程的回顾,结合湿地资源保护面临的严峻形势以及社会经济发展对评价研究的现实要求,重点剖析了湿地生态系统服务功能的现状评价模式在研究定位、评价内容、评价方式和评价体系建设几个方面存在的主要不足,在此基础上提出相应的改进思路和方案.认为评价模式的改进应当以维持湿地生态系统健康和支撑区域社会经济可持续发展为研究目标,面向湿地生态系统管理方向补充评价内容,完善评价体系,强调人为活动干扰对湿地生态系统服务的影响及反馈分析,重视人类社会对服务功能需求的评价,并详细阐述干扰评价、需求评价和服务功能供需平衡分析的主要内容、方法和难点,总结湿地管理的意识和手段在服务功能评价各环节的体现. 相似文献
998.
利用人GCSF基因组基因和cDNA基因作为目的片段,将其受控于2.6kb的小鼠乳清酸蛋白(WAP)基因的调控区下,通过显微注射法获得了两只整合有人GCSF转基因小鼠,通过繁殖建立了稳定的转基因系.一些表型参数测定表明,转基因鼠与正常鼠无明显差别,为对转基因动物进行安全性评价提供了依据 相似文献
999.
Blood lead concentration is still most commonly used to assess the degree of exposure to environmental lead. However, blood lead levels are relatively transient and so tissues such as hair which store lead over longer periods need to be explored as bioindicators of lead toxicity. The results of such an investigation into hair are presented. These results indicate that there are significant differences in scalp-hair levels between the African, East Indian and Chinese racial groups in the multiracial adult population of Trinidad, West Indies. However, no significant differences were found for the pubic hair levels among the three races. The percentage of sulphur or the carbon: sulphur ratios in scalp hair did not influence the scalp-hair lead levels in the general population, although a significant difference in the carbon:sulphur ratios was observed between the African and East Indian racial groups. 相似文献
1000.
清代的环境保护思想 总被引:1,自引:1,他引:0
丁俊娜 《中国环境管理干部学院学报》2005,15(2):97-99
清代的"天人合一"、"与天争胜"、倡导保护自然资源、反对暴殄天物的思想对我国的环境保护事业具有史鉴意义. 相似文献