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961.
Climatic change will result in great changes in vegetation. In this paper, a biogeographical model, the BIOME1, was used to
predict potential vegetation distribution in China under climate change. Firstly, the BIOME1 was validated according to the
climate–vegetation relationships in China. Kappa statistics showed that the validated BIOME1 was able to capture the geographical
patterns of vegetation more accurately. Then, the validated BIOME1 was used to predict the distribution of vegetation of China
under two climatic scenarios produced by a Regional Circulation Model, RegCM2/CN. The simulation results showed obvious northward
shifts of the boreal, temperate deciduous and evergreen and tropical forests, a large expansion of tropical dry forest/savanna
and reduction of tundra on the Tibetan Plateau. Three vulnerable regions sensitive to climate changes are pointed out, i.e.,
Northern China, the Tibetan Plateau and Southwestern China (mainly Hengduan Mountains in Yunnan Province and west of Sichuan
Province). In recent decades, China has experienced dramatic industrialization and population growth, which exert strong pressure
on the environment of China. The consequences of climate changes warrant more attention for maintaining a sustainable environment
for China. 相似文献
962.
Sonja Peterson 《Environmental Modeling and Assessment》2006,11(1):1-17
The analysis of climate change is confronted with large uncertainties that need to be taken into account to arrive at meaningful
policy recommendations. The main contribution of economics to this interdisciplinary task is to provide formal frameworks
and techniques for analyzing climate policy in the context of uncertainty. This paper will give an overview of existing approaches
and findings to provide a broad picture of what economics can contribute to the debate. 相似文献
963.
SAGAR V. KRUPA 《Environmental monitoring and assessment》1997,46(1-2):73-88
Our knowledge of global climate change has many uncertainties.Whether global air temperature will increase, by how much, and when,are subject to debate, but there is little doubt that troposphericconcentrations of several trace gases are increasing. While possibleincreases in the average air temperature is a product of these changes,the increases in the trace gases alone will have an effect on agriculture.Increases in the ambient concentrations of carbon dioxide are expectedto have a positive net effect on crop production. In contrast, anyincreases in the penetration of surface-level ultraviolet-B (280–320 nm)radiation, and known increases in surface ozone concentrations, areconsidered to have adverse effects on certain crops. Our presentknowledge of the joint effects on crops of elevated levels of carbondioxide, ultraviolet-B radiation and ozone, and possible alterations in airtemperature and precipitation patterns, is virtually zero. Therefore, anypredictions of the effects of global climate change on agriculture aresubject to significant uncertainties. In contrast, coupling of climatechange (only temperature and precipitation) models to crop productionhas led to a number of future scenarios. In spite of theirpresent limitations, results from these efforts can be useful in planningfor future agriculture. 相似文献
964.
天津市空气质量时间变化规律及相关性分析 总被引:12,自引:1,他引:12
按时间段对天津市环境空气监测国控点2005年的SO2、NO2和PM10监测数据进行统计分析,SO2、NO2和PM10时间变化规律呈现典型的双峰双谷型,SO2、NO2污染呈现明显的季节性,而PM10污染相对稳定。对SO2、NO2和PM10在全年、采暖期和非采暖期的时间变化进行相关性分析,结果表明,除了非采暖期NO2和SO2相关性不显著外,其它均存在较强的相关性。 相似文献
965.
Many governments use technology incentives as an important component of their greenhouse gas abatement strategies. These carrots are intended to encourage the initial diffusion of new, greenhouse-gas-emissions-reducing technologies, in contrast to carbon taxes and emissions trading which provide a stick designed to reduce emissions by increasing the price of high-emitting technologies for all users. Technology incentives appear attractive, but their record in practice is mixed and economic theory suggests that in the absence of market failures, they are inefficient compared to taxes and trading. This study uses an agent-based model of technology diffusion and exploratory modeling, a new technique for decision-making under conditions of extreme uncertainty, to examine the conditions under which technology incentives should be a key building block of robust climate change policies. We find that a combined strategy of carbon taxes and technology incentives, as opposed to carbon taxes alone, is the best approach to greenhouse gas emissions reductions if the social benefits of early adoption sufficiently exceed the private benefits. Such social benefits can occur when economic actors have a wide variety of cost/performance preferences for new technologies and either new technologies have increasing returns to scale or potential adopters can reduce their uncertainty about the performance of new technologies by querying the experience of other adopters. We find that if decision-makers hold even modest expectations that such social benefits are significant or that the impacts of climate change will turn out to be serious then technology incentive programs may be a promising hedge against the threat of climate change. 相似文献
966.
967.
C. Schlumpf J. Behringer G. Dürrenberger C. Pahl-Wostl 《Environmental Modeling and Assessment》1999,4(1):1-12
Participatory Integrated Assessment (PIA) is an approach which aims at developing methods which allow to combine evaluations
of experts and lay people in the field of Integrated Assessment. Thus, policy recommendations derived from PIA exercises are
informed by scientific judgments and by valuations of “non-scientists”. For any PIA methodology the provision of insights,
facts and figures about the policy problem at hand is crucial.
In this paper we describe a PIA methodology which combines the social science research instrument “focus group” with a specific
computer information tool, the “Personal CO2 Calculator” (PCC). The tool supports citizens in discussing and recommending measures on climate change policy. Based on
our experiences, we plead for information instruments that are tuned to and assist concrete target groups with their specific
interests. This helps that policy recommendations derived from PIA exercises are based on both scientific knowledge as well
as citizens' and stakeholders' policy preferences.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
968.
M.K.B. Lüdeke O. Moldenhauer G. Petschel-Held 《Environmental Modeling and Assessment》1999,4(4):315-326
Starting from the basic assumption of the syndrome concept that essentially all of the present problematic civilization–nature interactions on the global scale can be subdivided into a limited number of typical patterns, the analysis of the response of these patterns (syndromes) to climate change can make a major contribution to climate impact research, surmounting the difficulties of more common sectoral ceteris paribus impact studies with respect to their systemic integration. In this paper we investigate in particular the influence of climate on the regional proneness or disposition towards one of the most important syndromes with respect to famines and malnutrition, the Sahel Syndrome. It describes the closely interlinked natural and socioeconomic aspects of rural poverty driven degradation of soil and vegetation on marginal sites. Two strategies of global climate impact assessment on a spatial 0.5°×0.5° grid were pursued: (a) As a measure for the climate sensitivity of the regional proneness, the absolute value of the gradient of the disposition with respect to the global field of 3} 12 monthy normals of temperature, irradiation and precipitation is calculated. (b) The disposition was evaluated for two different climate forecasts under doubled atmospheric CO2 concentration. For both strategies two new quantitative global models were incorporated in a fuzzy-logic-based algorithm for determining the disposition towards the Sahel Syndrome: a neural-net-based model for plant productivity and a waterbalance model which calculates surface runoff considering vertical and lateral fluxes, both driven by the set of 36 monthly climatological normals and designed to allow very fast global numerical evaluation.Calculation (b) shows that the change in disposition towards the Sahel Syndrome crucially depends on the chosen climate forecast, indicating that the disagreement of climate forecasts is propagated to the impact assessment of the investigated socio-economic pattern. On the other hand the regions with a significant increase in disposition in at least one of the climate scenario-based model runs form a subset of the regions which are indicated by the local climate sensitivity study (a) as highly sensitive – illustrating that the gradient measure applied here provides a resonable way to calculate an upper limit or worst case of negative climate impact. This method is particularly valuable in the case of uncertain climate predictions as, e.g., for the change in precipitation patterns. 相似文献
969.
970.
Sergey Venevsky 《Mitigation and Adaptation Strategies for Global Change》2006,11(1):241-268
The conceptual scheme of integrated assessment of vulnerability to climate change in Siberian forests is elaborated and applied
to the extensive area in Siberia covered by Larch forests. Forest stakeholders on the provincial level are identified to be
the most relevant for an integrated impact assessment. Organisation of the assessment study as a combination of
'top-down' and 'bottom-up' approaches is suggested. Major biophysical vulnerability indexes and regional syndromes are identified
as the growing stock and current increment averaged by administrative unit. Models and data suitability and quality for an
analysis of biophysical vulnerability in conditions of climate change are studied for Siberian forests and future development
trends are identified. An application of the elaborated conceptual scheme, which employs two models of different type and
forest inventory data, is presented for the Larch area. 相似文献