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71.
72.
Vulnerability of land systems to fire: Interactions among humans,climate, the atmosphere,and ecosystems 总被引:3,自引:0,他引:3
Sandra Lavorel Mike D. Flannigan Eric F. Lambin Mary C. Scholes 《Mitigation and Adaptation Strategies for Global Change》2007,12(1):33-53
Fires are critical elements in the Earth System, linking climate, humans, and vegetation. With 200–500 Mha burnt annually,
fire disturbs a greater area over a wider variety of biomes than any other natural disturbance. Fire ignition, propagation,
and impacts depend on the interactions among climate, vegetation structure, and land use on local to regional scales. Therefore,
fires and their effects on terrestrial ecosystems are highly sensitive to global change. Fires can cause dramatic changes
in the structure and functioning of ecosystems. They have significant impacts on the atmosphere and biogeochemical cycles.
By contributing significantly to greenhouse gas (e.g., with the release of 1.7–4.1 Pg of carbon per year) and aerosol emissions,
and modifying surface properties, they affect not only vegetation but also climate. Fires also modify the provision of a variety
of ecosystem services such as carbon sequestration, soil fertility, grazing value, biodiversity, and tourism, and can hence
trigger land use change. Fires must therefore be included in global and regional assessments of vulnerability to global change.
Fundamental understanding of vulnerability of land systems to fire is required to advise management and policy. Assessing
regional vulnerabilities resulting from biophysical and human consequences of changed fire regimes under global change scenarios
requires an integrated approach. Here we present a generic conceptual framework for such integrated, multidisciplinary studies.
The framework is structured around three interacting (partially nested) subsystems whose contribute to vulnerability. The
first subsystem describes the controls on fire regimes (exposure). A first feedback subsystem links fire regimes to atmospheric
and climate dynamics within the Earth System (sensitivity), while the second feedback subsystem links changes in fire regimes
to changes in the provision of ecological services and to their consequences for human systems (adaptability). We then briefly
illustrate how the framework can be applied to two regional cases with contrasting ecological and human context: boreal forests
of northern America and African savannahs. 相似文献
73.
74.
L. Tudorachi 《Environmental Forensics》2014,15(3):213-218
The right to a healthy environment is of capital importance, which is why this matter calls for a detailed study, taking into account implications of both chemistry and law. The present study describes the current level of environmental protection, significant pieces of legislation, and five case studies regarding human rights violations. It reveals reports concerning air quality in Romania and in Europe. A large body of evidence emphasizes that permanent legislation revisions and new legal implementations place Europe on the right track, but plenty of issues remain to be solved until main pollutant emissions drop and the environmental situation becomes at least satisfactory. 相似文献
75.
Atmospheric emissions of some POPs in Europe: a discussion of existing inventories and data needs 总被引:2,自引:0,他引:2
Accurate and complete information on the emissions of persistent organic pollutants (POPs) are essential for interpreting historical, current and future contamination levels in remote areas. However, this information is also crucial for decision makers aiming at further reduction of the environmental loading of these substances on a regional scale. In this study, we identify and discuss specific POP emission inventory features that are deemed essential to understand, predict and control the behaviour of such substances on a European scale. It is shown that the scientific value of official emission data is limited (e.g. for deriving source–receptor relationships on a European scale), as there is insufficient information on spatial, temporal and compound coverage. Likewise, we argue that non-official emission data (i.e. research-driven emission inventories), which are based on aggregated statistics, may be of limited value for the identification of further emission control strategies. It is thus argued that future emission inventories should be developed in a format that is suitable to serve both policy- and research-oriented applications. Further improvement of official emission data with respect to research-driven features seems to be the most sensible way to proceed. Finally, the empirical basis of current emission inventories remains weak, and further research on emission identification and characterisation seem needed (a) to gain confidence in predicted source–receptor relationship as well as (b) for the development of sound control strategies. 相似文献
76.
Jaroslav Hynt Miloslav imek Petr Br
ek Sren O. Petersen 《Agriculture, ecosystems & environment》2007,120(2-4):269-279
Cattle overwintering areas common in central Europe may represent significant point sources of the important greenhouse gases, nitrous oxide (N2O) and carbon dioxide (CO2). A 2-year field study was carried out in order to estimate the emissions of N2O and CO2 from soil in a cattle overwintering area located in the southwest of the Czech Republic. The measurements were performed at three sampling locations along a gradient of animal impact (severe, moderate, slight) to test the hypothesis that emissions of CO2 and N2O are positively related to the degree of impact. In addition to CO2 and N2O fluxes determined by using non-vented manual closed chambers, soil mineral nitrogen (NH4+ and NO3−), pH and temperature were determined to assess their regulatory role and impact on gas fluxes. The overwintering area was about 4 ha and it had been used for overwintering of about 90 cows since 1995. Deposition of animal excreta resulted in a significant accumulation of nitrogen in the soil during winter, but most of the N2O was emitted during a few short periods in spring and/or in late autumn. Maximum N2O fluxes of up to 2.5 mg N2O-N m−2 h−1 were recorded at the most impacted location near the animal house, where the highest concentrations of soil mineral nitrogen also occurred. The emissions of CO2 showed a completely different pattern to those of N2O, being correlated with soil temperature; the highest emissions thus occurred in June–July, while very low fluxes were found in winter. Emission values ranged from about 0 to 700 mg C-CO2 m−2 h−1. Furthermore, the effect of animal impact on CO2 emissions was opposite to that on N2O fluxes, as the highest CO2 fluxes were mostly recorded at the least impacted location, where respiration of plants most likely increased overall CO2 production. The results show that cattle overwintering areas are important sources of greenhouse gases, including N2O and CO2. Fluxes of these two gases are, however, differently distributed over the year, which also suggests that they are controlled by different environmental and soil factors. 相似文献
77.
Broz J Grabic R Kilián J Lojkásek M Marklund S Ocelka T Pekárek V Pribyl J Tydlitát V Výska J 《Chemosphere》2000,41(12):1948-1911
The effect of synthetic and mineral oils on the formation of polyaromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in emissions from a spark ignition engine was studied on a Skoda Favorit engine fueled with leaded gasoline. The test cycle simulated urban traffic conditions on a chassis dynamometer, in accordance with the ECC 83.00 test. The data for selected PAHs as well as PCDDs, PCDFs, and PCBs congener profiles are presented. PCDD/Fs emissions for an unused oil and the oil after 10000-km operation varied from 300 to 2000 fmol/m3, PCBs emissions from 75 to 178 pmol/m3, and PAHs emissions from 150 to 420 microg/m3. The content of PCBs in oils varied from 2 to 920 mg/kg. 相似文献
78.
建立了碳排放权省区分配模型,在中国2020年和2030年碳强度目标约束下,分阶段进行碳排放权的省区分配.结果表明:2016~2020年,中国各地区碳排放权分配相差悬殊.碳排放权配额最多的5个省份分别是经济发展水平和历史碳排放量均处于全国前列的广东、江苏、内蒙古、山东和山西地区,配额最少的5个省份依次是安徽、吉林、甘肃、宁夏和贵州.同时,各地区面临不同的减排压力.山西、山东、辽宁和陕西在2016年初始节点的碳空间严重不足,需要承担较大的减排压力.而广东、江苏和上海等地减排压力相对乐观.2021~2030年,各省份的碳排放权分配与第1阶段分配结果大体一致,所有省份在2030年碳排放空间均有盈余.但是部分地区(如新疆、陕西、吉林、青海、甘肃、宁夏和贵州等)截至2030年碳排放剩余空间相对有限,按期完成减排目标仍然存在较大压力.考虑到各省区面临不同的减排任务和压力,制定差异化的减排政策并在政策上给予适当的扶持是保证中国减排目标顺利达成的关键. 相似文献
79.
通过科学合理地划分河段实现栖息地分类管理是恢复流域生物完整性的重要内容之一.湖泊流域入湖河流空间尺度小、坡降大、生态学过程差异性显著的特点导致其河段类型复杂多样,与河流流域河段类型的大尺度特征具有明显区别,因此,河流流域河段划分指标及其方法不适用于湖泊流域,亟需发展以栖息地分类管理为目的的湖泊流域河段划分方法.本文通过回顾河流分类的概念、划分依据及划分方法的发展历程,明确了湖泊流域河段划分理论基础,提出了基于保护目标制定的湖泊流域河段划分方法,为恢复湖泊流域生物完整性提供了更为精细的管理单元.同时,以滇池流域为例,通过筛选与大型底栖动物敏感种群和濒危种群显著相关的环境因子,建立了由地貌类型、土地利用方式、河水来源、河道人工化情况及水体营养程度构成的指标划分体系;在实现各划分指标空间化的基础上,利用空间叠加聚类技术手段,将滇池流域入湖河流划分为9个河段类型,为滇池流域水生态系统健康恢复提供了科学依据. 相似文献
80.
Antonio D. Dorado Shafik Husni Guillem Pascual Carles Puigdellivol David Gabriel 《Waste management (New York, N.Y.)》2014,34(2):344-351
Emissions of volatile organic compounds (VOCs) from the compost maturation building in a municipal solid waste treatment facility were inventoried by solid phase microextraction and gas chromatography–mass spectrometry. A large diversity of chemical classes and compounds were found. The highest concentrations were found for n-butanol, methyl ethyl ketone and limonene (ppmv level). Also, a range of compounds exceeded their odor threshold evidencing that treatment was needed. Performance of a chemical scrubber followed by two parallel biofilters packed with an advanced packing material and treating an average airflow of 99,300 m3 h?1 was assessed in the treatment of the VOCs inventoried. Performance of the odor abatement system was evaluated in terms of removal efficiency by comparing inlet and outlet abundances. Outlet concentrations of selected VOCs permitted to identify critical odorants emitted to the atmosphere. In particular, limonene was found as the most critical VOC in the present study. Only six compounds from the odorant group were removed with efficiencies higher than 90%. Low removal efficiencies were found for most of the compounds present in the emission showing a significant relation with their chemical properties (functionality and solubility) and operational parameters (temperature, pH and inlet concentration). Interestingly, benzaldehyde and benzyl alcohol were found to be produced in the treatment system. 相似文献