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261.
Patricia N. Manley William J. Zielinski Claudia M. Stuart John J. Keane Amy J. Lind Cathy Brown Beth L. Plymale Carolyn O. Napper 《Environmental monitoring and assessment》2000,64(1):139-152
Monitoring at large geographic scales requires a framework for understanding relationships between components and processes of an ecosystem and the human activities that affect them. We created a conceptual model that is centered on ecosystem processes, considers humans as part of ecosystems, and serves as a framework for selecting attributes for monitoring ecosystems in the Sierra Nevada. The model has three levels: 1) an ecosystem model that identifies five spheres (Atmosphere, Biosphere, Hydrosphere, Lithosphere, Sociocultural), 2) sphere models that identify key ecosystem processes (e.g., photosynthesis), and 3) key process models that identify the "essential elements"that are required for the process to operate (e.g., solar radiation), the human activities ("affectors") that have negative and positive effects on the elements (e.g., air pollution), and the "consequences"of affectors acting on essential elements (e.g., change in primary productivity). We discuss use of the model to select attributes that best reflect the operation and integrity of the ecosystem processes. Model details can be viewed on the web at http://www.r5.fs.fed.us/sncf/spam_report/index.htm(Appendix section). 相似文献
262.
Kelly R. Bright Enue E. Sicairos-Ruelas Patricia M. Gundy Charles P. Gerba 《Food and environmental virology》2009,1(1):37-41
The antiviral properties of zeolite (sodium aluminosilicate) powders amended with metal ions were assessed using human coronavirus
229E, feline infectious peritonitis virus (FIPV), and feline calicivirus F-9. Zeolites containing silver and silver/copper
caused significant reductions of coronavirus 229E after 1 h in suspension. The silver/copper combination yielded a >5.13-log10 reduction within 24 h. It was also the most effective (>3.18-log10) against FIPV after 4 h. Other formulations were ineffective against FIPV. On plastic coupons with incorporated silver/copper-zeolites,
>1.7-log10 and >3.8-log10 reductions were achieved for coronavirus 229E and feline calicivirus within 24 h, respectively. Silver/copper zeolite reduced
titers of all viruses tested, suggesting that it may be effective against related pathogens of interest [i.e., SARS coronavirus,
other coronaviruses, human norovirus (calicivirus)]. Of note, it was effective against both enveloped and nonenveloped viruses.
Metal-zeolites could therefore possibly be used in applications to reduce virus contamination of fomites and thus the spread
of viral diseases. 相似文献
263.
264.
Félix J. González-EstébanezSergio García-Tejero Patricia Mateo-Tomás Pedro P. Olea 《Agriculture, ecosystems & environment》2011,144(1):262-270
Irrigation effects on biodiversity are poorly known, particularly in Mediterranean agro-ecosystems. In this study we analyzed irrigation effects on butterfly species richness, abundance and diversity as well as on species composition in a farmed landscape under Mediterranean climate. The study area consisted of four contiguous agricultural sub-areas with a decreasing degree of intensification: irrigated, mixed (dry and irrigated), dry and environmentally protected (i.e. Special Protection Area, SPA) dry farmland. Forty one km-transects (ten per sub-area) were searched for butterflies in 2008 and 2009. Contrary to expectations, species richness (alfa, beta and gamma diversity) was highest in both years in the most intensified sub-area (i.e. irrigated) followed by SPA, dry and mixed sub-areas. Landscape characteristics accounted for most of the between-subareas differences in species richness. Species richness was negatively related to mean field size at the landscape level and positively related to the number of trees and large shrubs along transects. Therefore, the higher number of butterfly species recorded in the irrigated farmland could be due to a more complex landscape. In contrast, butterfly abundance was highest in cereal steppes (i.e. dry and SPA sub-areas), with abundance being negatively affected by mean field size. Inter-annual change in butterfly abundance was much sharper in rainfed (i.e. dry and SPA) than in irrigated (i.e. irrigated and mixed) sub-areas. Irrigated farmland may provide more favorable conditions for butterflies by buffering the (year-to-year and summer) drought periods characterising Mediterranean climate. Species composition differed among sub-areas, with differences being partly explained by field size and number of trees and shrubs along transects. Our study suggest an important role of landscape characteristics in boosting butterfly biodiversity in intensively managed irrigated croplands and emphasizes the importance of encouraging studies on farmland butterfly diversity in different (bioclimatic) regions allowing the design of region-specific agri-environmental schemes. 相似文献
265.
Tracey N. Johnson Patricia L. KennedyTim DelCurto Robert V. Taylor 《Agriculture, ecosystems & environment》2011,144(1):338-346
In 2006-2010, effects of four different cattle stocking rates (0, 14.4, 28.8, and 43.2 animal unit months) were compared, representing 0%, 20%, 32%, and 46% utilization of vegetation by domestic livestock, on vegetation structure (as indexed by visual obstruction), and songbird population and apparent nest density, community composition, and diversity in a Pacific Northwest bunchgrass prairie in northeastern Oregon, USA. Overall paddock-level visual obstruction decreased and structural heterogeneity increased with increasing stocking rates, and those effects carried over 1 year after grazing had ceased. Most species were able to locate nesting sites regardless of differences in visual obstruction, except western meadowlark and vesper sparrow, for which obstruction was lower in paddocks with higher stocking rates. Apparent nest density for grasshopper sparrows was negatively affected by higher stocking rates. Grazing effects on absolute songbird population density were restricted to negative effects of higher stocking rates on savannah sparrows, but this relationship was not observed until 1 year after grazing had ceased. Songbird community composition differed between control and heavily-grazed paddocks, driven by an increase in the proportion of horned larks and a decrease in the proportion of savannah sparrows in heavily-grazed paddocks from pre-treatment to post-treatment years. Bird diversity indices were unaffected by stocking rate. Negative effects of high stocking rates on densities of two species and the absence of any clear positive effect for the other three species suggest high stocking rates as applied in this experiment may not provide suitable habitat for all grassland songbirds. The absence of negative responses of density to low and moderate stocking rates suggests these grazing regimes generally provided suitable habitat for all species. 相似文献
266.
Patricia Fitzpatrick Alberto FonsecaMary Louise McAllister 《Journal of Cleaner Production》2011,19(4):376-384
Much debate has taken place within the mineral policy community about whether or not meaningful progress has been made towards more sustainable practices. This paper investigates the changing approaches towards sustainable development undertaken by the Mining Association of Canada (MAC) over a period of approximately 20 years. The analysis begins in the early 1990s when MAC initiated the Whitehorse Mining Initiative (WMI) and concludes in 2010 when the association was operating under a strategy entitled Towards Sustainable Mining (TSM). The goal is to consider the nature of the learning that has taken place towards sustainability within the mineral industry using the case of a leading national mining association. The investigation was undertaken through a literature review as well as key informant interviews with stakeholders affected by the Canadian Mining Industry. Findings suggest that MAC’s approach to sustainable development has shifted from an ambitious and holistic partnership involving a range of stakeholders to a focused, member-specific agenda that addresses a few performance issues. The transition to TSM was based on lessons learned through working with the WMI and subsequent efforts. It reflects broader corporate tendencies to address social and ecological issues through corporate social responsibility initiatives. The implications of these trends suggest that voluntary initiatives in and of themselves should not be expected to replace the comprehensive regulatory responsibilities historically provided by government. 相似文献
267.
Shechtman O Classen S Stephens B Bendixen R Belchior P Sandhu M McCarthy D Mann W Davis E 《Traffic injury prevention》2007,8(1):78-86
PURPOSE: The Federal Highway Administration (FHWA) proposed guidelines for highway design to increase the safe driving ability of older drivers; however, little empirical evidence exists to support the effectiveness of these guidelines. The purpose of this study was to investigate the effects of implementing these guidelines (in 4 pairs of intersections) on safe driving performance of older and younger drivers using a high-fidelity driving simulator. DESIGN AND METHODS: We replicated four intersection pairs (improved versus unimproved) in a high-fidelity, virtual reality driving simulator. Simulator scenarios were created from actual road locations, replicating road geometrics and traffic control devices. The simulator's controls were integrated with an actual vehicle to make the driving experience as realistic as possible. Kinematic measures were obtained from the simulator in conjunction with driving errors recorded by trained driving evaluators sitting in the cab of the car. Thirty-nine subjects, 19 younger and 20 older adults, participated in the study. RESULTS: For the kinematic data we found greater lateral control, as indicated by significantly smaller maximum yaw during the turn phase, at all of the improved intersections when compared to the unimproved intersections. We found some significant age differences, but mostly in only one of the intersection-pairs. For the behavioral data, there were significant differences in driving errors between improved and unimproved intersections in two intersection-pairs; however, there were no significant differences in driving errors between the older and younger drivers. IMPLICATIONS: The findings suggest that both young and older drivers may benefit from roadways with safety features recommended by the FHWA guidelines as indicated by the increased lateral control of the vehicle when negotiating these intersections. These findings generate critical information for those involved in the design of roadway systems. 相似文献
268.
Classen S Shechtman O Stephens B Davis E Justiss M Bendixen R Belchior P Sandhu M Posse C McCarthy D Mann W 《Traffic injury prevention》2007,8(1):69-77
OBJECTIVE: To test the effectiveness of the FHWA guidelines for intersection design. METHODS: In an experimental design we used kinematics measures from an instrumented vehicle and behavioral (error) data collected during on-road evaluations to quantify the effects of improved versus unimproved intersections (turn phase) and to determine if these intersections were safer (vehicular stability and driver confidence) for both older (65-85 years) and younger (25 -45) drivers. We analyzed kinematics data with a 2 x 2 repeated measures ANOVA and behavioral data (driving errors yes, no) with Wilcoxon sign rank test (within subject variable: intersection improved vs. unimproved) and Wilcoxon rank sum test (between subject variable: age, younger vs. older driver). RESULTS: Kinematics measures (turn phase), showed three maneuvers had statistically significantly lesser side forces (measured by lateral acceleration and combined acceleration) for the improved conditions, and four maneuvers had statistically significantly greater, yet appropriate, speeds for the improved conditions. Lesser side forces indicated improved lateral stability and increased speed indicated greater confidence. Drivers made fewer errors on two of the improved intersections; but across all maneuvers, older drivers appeared to make fewer errors on the improved intersections. CONCLUSIONS: This study brings empirical intersection design and safety information for engineers and city planners to consider as they plan and develop intersections. Future researchers may want to use the conceptual and analytical framework of this study to determine the effectiveness of other FHWA guidelines. Given that these intersection design guidelines benefit younger and older drivers alike, plausible policy-making opportunities are opened in the design of safe roadway systems, to benefit the broad spectrum of adult drivers. 相似文献
269.
Pauline Vuarin Roland Allemand Joffrey Moiroux Joan van Baaren Patricia Gibert 《Die Naturwissenschaften》2012,99(11):903-912
Energy allocation is determined by resource availability and trade-offs among traits, and so organisms have to give some traits priority over others to maximize their fitness according to their environment. In this study, we investigated the geographic variations in life history traits and potential trade-offs in populations of the parasitoid Leptopilina heterotoma (Hymenoptera: Figitidae) originating from the north and the south of the Rh?ne–Sa?ne valley (over a gradient of 300?km, South-East France). We measured a set of traits related to reproduction, maintenance, and mobility using several estimators of each of these main functions determined at different times. We did not find any clear differences between populations from contrasting areas, whereas the southern populations, which were all assumed to be exposed to similar environmental conditions, displayed contrasting patterns of energy allocation. Thus, the most likely explanation seems to be that the evolution of the life history of L. heterotoma is probably shaped by local selective pressures, such as microclimate, microhabitats, or intensity of competition, rather than by regional ecological conditions. Using our study as an example, we discuss the interest of considering several traits and using different ways of measuring them, concluding that multiple measurements should be performed in future studies to ensure the robustness of the results. 相似文献
270.
Introduction: The aims of this study were to provide further evidence of validity and reliability for the Driving Anger Expression Inventory (DAX) French adaptation (Villieux & Delhomme, 2008, Le Travail Humain, 71(4), 359-384) and to investigate the relationships between driving anger, how people express their anger while driving, and traffic violations among young drivers in France. Method: The French adaptations of the DAX, of the Driving Anger Scale (DAS), and of the Extended Violations Scale were administered to a sample of 314 drivers. Results: Confirmatory factor analysis of the French DAX items yielded a three factors solution with 11 items, which obtained better goodness-of-fit to the data. Cronbach α reliabilities for DAX factors ranged from .71 to .79. Aggressive forms of anger expression correlated positively with driving anger and traffic violations whereas the 'Adaptive/Constructive Expression' factor correlated negatively with these variables. Discussion: Globally, our results replicated earlier findings and showed that DAX factors are useful predictors of self reported violations and complement established measures like the DAS. Impact on Industry: Implications for driver education and interventions were examined. 相似文献