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961.
Jennifer L. Murrow Cindy A. Thatcher Frank T. van Manen Joseph D. Clark 《Environmental Modeling and Assessment》2013,18(2):159-170
Habitat loss and fragmentation are the greatest threats to the endangered Florida panther (Puma concolor coryi). We developed a data-based habitat model and user-friendly interface so that land managers can objectively evaluate Florida panther habitat. We used a geographic information system (GIS) and the Mahalanobis distance statistic (D 2) to develop a model based on broad-scale landscape characteristics associated with panther home ranges. Variables in our model were Euclidean distance to natural land cover, road density, distance to major roads, human density, amount of natural land cover, amount of semi-natural land cover, amount of permanent or semi-permanent flooded area–open water, and a cost–distance variable. We then developed a Florida Panther Habitat Estimator tool, which automates and replicates the GIS processes used to apply the statistical habitat model. The estimator can be used by persons with moderate GIS skills to quantify effects of land-use changes on panther habitat at local and landscape scales. Example applications of the tool are presented. 相似文献
962.
Joseph C. Feng Surindar S. Sidhu Cecilia C. Feng 《Journal of environmental science and health. Part. B》2013,48(6):639-654
Abstract The spatial distribution of hexazinone and two primary metabolites were measured in forest soil for two years following the aerial application of a granular formulation, PRONONE 10G, in northern Alberta. Residues were quantified using solid‐phase extraction and capillary gas chromatography. Initial deposition rates of two hexazinone treatments averaged 2.3 ± 0.5 and 4.1 ± 0.8 kg/ha for each triplicated plots. One year after application, residues of hexazinone averaged 0.25 ± 0.09 and 0.40 ± 0.02 kg/ha in 2.3 and 4.1 kg/ha treatment, respectively, in the 0–10 cm surface soil; and were distributed vertically in soil depths of 0–10, 10–20, and 20–30 cm at ratios of 10:11:2 and 10:5:2, respectively, in 2.3 and 4.1 kg/ha treatment. Metabolites A and B amounted to 15 and 30% of hexazinone, respectively. Two years after application, the vertical movement of hexazinone in soil was quantifiable to the 40‐cm depth in both 2.3‐ and 4.1‐kg/ha treatment plots. Trace amounts of hexazinone were detected at 130 cm only in the 2.3‐kg/ha plot, which is likely due to the more freely downward movement of hexazinone to deeper horizons along decayed root channels. 相似文献
963.
We studied the impact of demographic diversity on individual attachment and firm unit performance in a relatively diverse organization. We implemented cross‐level regression to study gender and race/ethnic categorical, relational, and organizational demography in a sample of 26 units part of a regional restaurant chain. At the individual level, we found that diversity climate (DC) moderates the impact of relational and categorical demography on affective organizational commitment, organizational identification, and intention to quit. At the organizational level, we found that DC moderates the impact of organizational diversity on firm productivity and return on profit. We discuss the importance of organizational DC as organizational context on individual attachment, and implications for firm effectiveness in diverse organizations. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
964.
Peter O. Otieno Joseph O. Lalah Munir Virani Isaac O. Jondiko Karl-Werner Schramm 《The Environmentalist》2011,31(4):382-393
The increasing number of incidences of alleged wildlife poisoning with Furadan in Kenya has sparked off a strong lobby fronted
by wildlife conservationists against Furadan use in the country and prompted this study. The worst-case scenario was in 2004
in Athi River, where a massive number of 187 African white-backed vultures (Gyps africanus) and hyenas were found dead at a spot where poisoning was suspected to have occurred through a Furadan-laced camel carcass
bait. This study was initiated by the Peregrine Fund—Africa Project, and the objective was to provide evidence for Furadan
exposure, its misuse and involvement in vulture poisoning and potential impact on areas near two wildlife conservancies in
two most affected districts. The study found evidence for ready availability of Furadan 5G in local veterinary retail shops
and its illegal misuse by pastoralists and farmers against wildlife to protect their animals and crops. Analysis of soil,
water and plants taken from the farms and water sources by high-perfomance liquid chromatography (HPLC) and gas liquid chromatography–mass
spectrometry (GC–MS) found residues of carbofuran, 3-hydroxycarbofuran and 3-ketocarbofuran, indicating that Furadan was used
extensively in farming causing residual environmental distribution and contamination and posing risks to small birds and mammals.
Forensic analysis of residues in beaks, feet and crop content of the dead vultures as well as in a laced camel carcass bait
and soil samples from one site of poisoning also showed carbofuran and its two metabolites supporting allegations of Furadan
involvement in wildlife poisoning and high-mortality cases of African white-backed vultures (Gyps africanus) in Kenya. 相似文献
965.
Iheoma M. Adekunle Joseph A. Ogundele Olusegun Oguntoke Oluseyi A. Akinloye 《Environmental monitoring and assessment》2010,170(1-4):467-474
Assessment of lead in blood (BLL) and lead in urine (ULL) of some non-occupationally exposed, nonsmoking 214 pregnant Nigerian women, aged 17 to 49 years, and resident in Lagos was carried out using atomic absorption spectrometry with control subjects consisting of 113 nonpregnant women. From results, the mean BLL and ULL (μg/dL) for pregnant women (59.5 ± 2.1; 29.4 ± 1.1) were significantly (p?<?0.01) higher than the values obtained for nonpregnant women (27.7 ± 1.1; 9.2 ± 0.6). BLL found in women in the first, second, and third trimesters were 57.2 ± 2.3, 61.6 ± 2.2, and 63.1 ± 1.8, respectively. ULL could not serve to predict BLL due to weak correlations (r?=???0.06 to +?0.15; p?>?0.10). Study is a contribution to blood and urine lead status of Nigerian pregnant women, being relevant for healthcare management purposes, public health decision making, and possible primary prevention activities. 相似文献
966.
Joseph Sherma 《Journal of environmental science and health. Part. B》2013,48(6):417-430
Techniques and applications of thin layer chromatography (planar chromatography) for the separation, detection, qualitative and quantitative determination, and preparative isolation of pesticides and their metabolites and some related pollutants are reviewed for the period from November 1, 2010 to November 1, 2012. Analyses are described for a variety of samples types and pesticide classes. In addition to references on residue analysis, studies such as pesticide structure – retention relationships, identification and characterization of natural and synthesized pesticides, metabolism, degradation, mobility, lipophilicity, and mechanism of action are covered. 相似文献
967.
Although most researchers now espouse a person‐by‐situation interactionist approach, there remains much work to be carried out to fully understand how different features of the environment interact with personality to influence behavior. Thus, this study sought to examine the moderating effects of three group‐level constructs on the relationships between two personality traits (conscientiousness and extraversion) and individual performance and counterproductive behaviors. Specifically, using trait activation theory as an organizing framework, we considered the moderating effects of the following: (i) a previously unexamined construct called core group evaluations (CGEs); (ii) group conscientiousness composition; and (iii) group extraversion composition. Data were obtained from a sample of university football players (N = 225–252 from 40 groups). The results indicated that CGEs moderated the relationships between individual conscientiousness and both performance (subjective) and counterproductive behaviors. Group conscientiousness composition also moderated the relationships between individual conscientiousness and both performance (objective and subjective) and counterproductive behaviors. Lastly, group extraversion composition moderated the relationship between individual extraversion and counterproductive behaviors. These findings highlight the importance of considering a team's CGEs, as well as the personality composition of team members when investigating the effects of conscientiousness and extraversion on individual performance and counterproductive behaviors. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
968.
Effects of Increasing Urbanization on the Ecological Integrity of Open Space Preserves 总被引:3,自引:0,他引:3
This article analyzes the effects of increasing urbanization on open space preserves within the metropolitan area of Phoenix,
Arizona, USA. Time series analysis is used in 10-year increments over 40 years to study urban landscape change. Three landscape
metrics—(1) matrix utility (measures intensity of adjacent land uses), (2) isolation (measures distances to other open space
patches), and (3) connectivity (measures physical links to other open space patches and corridors)—are used to assess changes
in landscape patterns and serve as indicators of urban ecological integrity of the open space preserves. Results show that
in the case of both open space preserves, general decline in indicators of urban ecological integrity was evident. The matrix
utility analysis demonstrated that increasing intensity of land uses adjacent to preserve is likely to increase edge effects,
reducing the habitat value of interior or core habitat areas. Isolation analysis showed that both preserves have experienced
increasing isolation from other open space elements over time. Also, connectivity analysis indicated that terrestrial connections
to other open space elements have also deteriorated. Conclusions of this research demonstrate that while preservation of natural
areas as open space is important in an urban context, intense development of surrounding areas reduces the urban ecological
integrity significantly. 相似文献
969.
The US is entering into a new era in space. The Vision for Space Exploration (VSE) (Bush, 2004) announced by the US President has been fleshed out during the Exploration Systems Architecture Study (ESAS) (ESAS Team Final Report, 2005) and work has been underway since then to develop a generation of launch vehicles to implement the preferred 1.5 launch architecture identified in the study. The 0.5 part of the launch set indicates the smaller Crew Launch Vehicle in the new set designated Ares I by NASA. The Ares I was selected by the team because analysis had shown that its complement of a solid first stage, with a liquid H2/O2 cryogenic second stage offered the best potential balance among cost, risk and performance. In particular the risk that this conceptual design would impose on the crew once matured was forecasted to be an order of magnitude better than the current matured crewed launcher set, the Soyuz and the Space Shuttle (Isakowitz, 2004). This forecast relied heavily on the experience of the heritage systems upon which the concept was based, specifically the heritage of the Shuttle solid rocket boosters and the experience with cryogenic upper stage engines from the Apollo and Shuttle era. Even with this strong heritage in play, it was recognized by the ESAS Risk Analysts that it would be necessary to mature the design with a set of test flights prior to placing the crew at risk. However the question was and is: “How many test flights are necessary before a crewed flight should be attempted?”This is the question that this paper addresses. That is, it is clear that the number of test flights is related to the desired safety level and that this, in turn, is related to what safety goal should be assigned to enable the crewed flight. Further, demonstration of goal achievement is again in turn related to how much of the heritage base can be captured in the new design. In the extreme, for a completely “new” design, the demonstration would be bounded by the requirements of the identical, repeatable experiments of classical probability theory (Mises, 1957). Even if the tens, or even hundreds of launches that this would require would be financially possible, tests of developmental systems are seldom, if ever, identical and repeatable because the design is modified to address the failure events observed. On the other hand, if the design was completely identical to the heritage then the heritage demonstrated reliability could be subsumed compared to the goal without further testing. This paper addresses the role of heritage in a developmental environment in the establishment of a minimum goal for the initiation of crewed missions and the testing required for its demonstration. 相似文献
970.