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991.
G. S. Kalacheva E. S. Zadereev V. G. Gubanov I. V. Gribovskaya 《Russian Journal of Ecology》2000,31(2):113-117
The chemical composition of water conditioned by colonies ofMoina macrocopa and involved in the regulation of their life cycle was analyzed in comparison with water samples from natural water bodies.
Dechlorinated tap water was used as the control medium. The results showed that metabolism of crustaceans leads to an increase
in the concentrations of phosphorus and nitrogen in all forms, the appearance of protein and carbohydrate fractions, and changes
in the composition of lipid fractions in the water conditioned by their colonies. The contents of all organic components are
very low, which makes their identification difficult. Concentrations of substances identified in the conditioned water do
not exceed those occurring in nature. 相似文献
992.
R. Janikowski R. Kucharski A. Sas-Nowosielska 《Environmental monitoring and assessment》2000,60(1):89-102
Errors in environmental resource management over the years have created pollution problems in some areas which are difficult to handle, regardless of the development of knowledge and technologies. This is particularly true in the case of soil pollution. The negative effects of persistent pollutants have been observed for a long time. For instance, lead and cadmium remain in the soil for centuries, during which time they are absorbed by plants and simultaneously cause secondary air pollution. The authors made an attempt to describe and assess the possible options of dealing with the problem of contaminated land in Katowice District. Considering the necessity of a multilateral approach, a pairwise comparison technique has been chosen as the most suitable to show the complexity of the problem. The different variants of actions aimed at preventing the pollutants from getting into the food chain were analyzed against a set of criteria, consisting of the following issues: time, cost, effectiveness, social acceptance, feasibility. The relative importance of actions were judged by the team of experts using the Saaty method. Also, a two-perspective assessment (the two different stakeholders), which involves considering the perspective of an owner of a piece of contaminated land and an ecologist has been performed. The results of comparative, multicriteria and multi-perspective assessment indicate the following:- the best method for contaminated agricultural land management is willful and controlled cultivation,- other recommended actions are deep ploughing and phytoremediation,- there is not much acceptance for the other methods. 相似文献
993.
Decision–support systems in the field of integrated water management could benefit considerably from social science knowledge,
as many environmental changes are human-induced. Unfortunately the adequate incorporation of qualitative social science concepts
in a quantitative modeling framework is not straightforward. The applicability of fuzzy set theory and fuzzy cognitive maps
for the integration of qualitative scenarios in a decision–support system was examined for the urbanization of the coastal
city of Ujung Pandang, Indonesia. The results indicate that both techniques are useful tools for the design of integrated
models based on a combination of concepts from the natural and social sciences.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
994.
Abstract: Extinctions can leave species without mutualist partners and thus potentially reduce their fitness. In cases where non‐native species function as mutualists, mutualism disruption associated with species’ extinction may be mitigated. To assess the effectiveness of mutualist species with different origins, we conducted a meta‐analysis in which we compared the effectiveness of pollination and seed‐dispersal functions of native and non‐native vertebrates. We used data from 40 studies in which a total of 34 non‐native vertebrate mutualists in 20 geographic locations were examined. For each plant species, opportunistic non‐native vertebrate pollinators were generally less effective mutualists than native pollinators. When native mutualists had been extirpated, however, plant seed set and seedling performance appeared elevated in the presence of non‐native mutualists, although non‐native mutualists had a negative overall effect on seed germination. These results suggest native mutualists may not be easily replaced. In some systems researchers propose taxon substitution or the deliberate introduction of non‐native vertebrate mutualists to reestablish mutualist functions such as pollination and seed dispersal and to rescue native species from extinction. Our results also suggest that in places where all native mutualists are extinct, careful taxon substitution may benefit native plants at some life stages. 相似文献
995.
北京市土地利用分布与水质响应空间关系研究 总被引:2,自引:0,他引:2
以北京市16个水质监测断面和饮用水源地作为研究对象,利用2009—2010年16个水质监测自动站监测数据与2009年北京市土地利用数据,分析不同缓冲区内土地利用与过境水质之间的响应关系。研究结果表明,耕地产生的农业非点源污染对水质影响明显;在大尺度区域增加林地面积比例有利于改善水质;离水源近的农村居民用地对水质产生负面影响;工业建设用地对水质影响在较大尺度上更为显著。 相似文献
996.
以丹阳净水厂为例,选取大气非正常排放模式,预测了液氯钢瓶阀门泄漏及爆炸对周围环境和保护目标的影响,并模拟了钢瓶爆裂事故的后果,计算出事故发生时的初始警戒区半径,提出了相应的氯气泄漏防范措施。 相似文献
997.
998.
999.
高效液相色谱-原子荧光光谱联用分析土壤中形态砷 总被引:2,自引:0,他引:2
采用高效液相色谱(HPLC)-原子荧光光谱(AFS)联用技术分析土壤中亚砷酸盐[As(Ⅲ)]、二甲基砷(DMA)、一甲基砷(MMA)和砷酸盐[As(Ⅴ)]等4种形态砷,以磷酸为提取剂、抗坏血酸为还原剂,优化了水浴提取条件。As(Ⅲ)、DMA、MMA和As(Ⅴ)在7 min之内实现了完全分离,在1.00μg/L~100μg/L范围内线性良好,实验室检出限分别为0.25μg/L、0.36μg/L、0.39μg/L和0.51μg/L,土壤标准样品平行测定的RSD≤7.4%,加标回收率为79.5%~95.0%,提取率为74.6%~90.4%。 相似文献
1000.
There is an international divide between net emissions importers and net emissions exporters, with industrialised nations mainly falling into the former and emerging economies the latter. Integrating emissions transfers into climate policy, so as not to disadvantage export-intensive countries, has been suggested to increase participation in international emissions reduction commitments. Consumption-based scenarios are presented for the UK identifying the geographic and sectorial source of emissions to meet future consumer demands given the current international climate policy landscape. The analysis is applied to the UK yet the discussion is applicable to international climate policy; assigning national responsibility for global emissions reductions; and extending the mitigation potential for net importing countries. Two trajectories for UK consumption emissions are calculated in which (1) international reduction targets are consistent with those pledged today equating to four degrees of temperature rise and (2) international reduction targets achieve a two degree future. By 2050 it is estimated that UK consumption emissions are 40–260% greater than UK territorial emissions depending on the strength of global reduction measures, and assuming the UK meets its 80% reduction in 1990 emissions by 2050 target. Cumulative emissions are presented alongside emissions trajectories, recognising that temperature rise is directly related to every tonne of carbon emitted. Whilst this paper argues that the current UK emissions targets underestimate the UK's contribution to global mitigation for two degrees, it shows how expanding the focus of policy towards consumption introduces new opportunities for reduction strategies at scale. The paper advocates the implementation of consumption-based emissions accounting which reveals underexploited policy interventions and increases the potential to break down barriers that exist between industrialised and emerging economies in international climate policy. 相似文献