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921.
A dynamic aquatic model (DynA model) was previously developed to predict the fate of a chemical in aquatic scenarios characterized by daily or periodic changes in several input parameters. DynA model is here calibrated with data obtained from the literature in specific unsteady state scenarios, such as those of rice fields. The results obtained for two herbicides (cinosulfuron and pretilachlor) in rice paddy scenarios revealed the capability of the model to accurately predict water and sediment concentrations, as shown by some statistical indicators. Modelling efficiency (EF) values of 0.86-0.99 for the water compartment and of 0.77-0.84 for sediment show the good agreement between predicted and measured concentrations. An "external validation" was performed using measured data for a different herbicide (molinate) applied in a Portuguese paddy rice scenario. A sensitivity analysis for this volatile chemical revealed the influence of some climatic parameters (e.g. temperature) to the model outcomes, such as water and sediment concentrations. This confirmed the capability of DynA model as an efficient tool for the pesticide risk assessment in dynamic scenarios.  相似文献   
922.
A discussion of some of the deficiencies of Superfund and hazardous chemical site investigation and remediation is presented. Of concern is the adequacy of defining the constituents of concern; stormwater‐runoff monitoring; evaluating excessive bioaccumulation of hazardous chemicals in edible organisms; the extent and degree of groundwater pollution; modeling of pollutant transport in the vadose zone; translocation of subsurface pollutants to surface via plant roots, leaves, and flowers; protection of groundwater quality for nonpriority pollutants that impact aesthetic quality; and deficiencies in the quality of site data reports. Examples of these types of problems are discussed with suggestions on the approach that should be followed to improve the quality of site investigation and remediation. © 2004 Wiley Periodicals, Inc.  相似文献   
923.
In the present study, a meta‐analysis was carried out to clarify the association between disinfection byproducts (DBPs) in drinking water and human cancer risk worldwide. Kidney, colorectal, esophagus, urinary bladder, brain, breast, leukemia, lung, and rectum cancers were selected to perform this analysis. According to preferred reporting items for systematic review and meta‐analysis protocol (PRISMA) guidelines, the relevant studies were identified and selection criteria (inclusion and exclusion criteria) were applied. Next, effective subgroups in these studies (gender, type of drinking water source, and type of DBPs) were analyzed. The quality of the studies was evaluated using the Newcastle‐Ottawa Scale. In addition, this overall study included analyses of 16 case–control and 3 cohort studies. The overall odds ratio (OR) with 95% confidence intervals (CI) between DBPs and cancer risk was 1.01 (95% CI, 0.94–1.09). The summary ORs of cancer risk were 1.04 (95% CI, 0.89–1.19) for kidney; 0.98 (95% CI, 0.87–1.09) for colorectal; 1.07 (95% CI, 0.84–1.29) for esophagus; 0.93 (95% CI, 0.80–1.06) for pancreatic; 1.00 (95% CI, 0.83–1.18) for brain; 1.13 (95% CI, 0.99–1.26) for breast; 0.93 (95% CI, 0.72–1.13) for leukemia; and 1.18 (95% CI, 1–1.36) for lung cancers. The results of this meta‐analysis suggested that there is not a significant association between DBPs in water and cancer risk. In addition, subgroup analysis shows a positive association with colorectal and kidney cancer risk in men, as well as colon and breast cancers in females. Studies of both genders have shown a significant association between lung and pancreatic cancers. Moreover, this study finds a significant relationship between cancer rate and consumers of city water and bottled water sources. In analyzing different types of DBPs in water, chlorine and trichloromethane show a significant association in increasing cancer risk.  相似文献   
924.
925.
Journal of Material Cycles and Waste Management - The chemical characterization of the food waste allowed to discriminate between the pre-preparation and post-preparation residues from a...  相似文献   
926.
The International Union for Conservation of Nature (IUCN) Red List Categories and Criteria is a quantitative framework for classifying species according to extinction risk. Population models may be used to estimate extinction risk or population declines. Uncertainty and variability arise in threat classifications through measurement and process error in empirical data and uncertainty in the models used to estimate extinction risk and population declines. Furthermore, species traits are known to affect extinction risk. We investigated the effects of measurement and process error, model type, population growth rate, and age at first reproduction on the reliability of risk classifications based on projected population declines on IUCN Red List classifications. We used an age‐structured population model to simulate true population trajectories with different growth rates, reproductive ages and levels of variation, and subjected them to measurement error. We evaluated the ability of scalar and matrix models parameterized with these simulated time series to accurately capture the IUCN Red List classification generated with true population declines. Under all levels of measurement error tested and low process error, classifications were reasonably accurate; scalar and matrix models yielded roughly the same rate of misclassifications, but the distribution of errors differed; matrix models led to greater overestimation of extinction risk than underestimations; process error tended to contribute to misclassifications to a greater extent than measurement error; and more misclassifications occurred for fast, rather than slow, life histories. These results indicate that classifications of highly threatened taxa (i.e., taxa with low growth rates) under criterion A are more likely to be reliable than for less threatened taxa when assessed with population models. Greater scrutiny needs to be placed on data used to parameterize population models for species with high growth rates, particularly when available evidence indicates a potential transition to higher risk categories.  相似文献   
927.
In the western Amazon Basin, recent intensification of river‐level cycles has increased flooding during the wet seasons and decreased precipitation during the dry season. Greater than normal floods occurred in 2009 and in all years from 2011 to 2015 during high‐water seasons, and a drought occurred during the 2010 low‐water season. During these years, we surveyed populations of terrestrial, arboreal, and aquatic wildlife in a seasonally flooded Amazonian forest in the Loreto region of Peru (99,780 km2) to study the effects of intensification of natural climatic fluctuations on wildlife populations and in turn effects on resource use by local people. Shifts in fish and terrestrial mammal populations occurred during consecutive years of high floods and the drought of 2010. As floods intensified, terrestrial mammal populations decreased by 95%. Fish, waterfowl, and otter (Pteronura brasiliensis) abundances increased during years of intensive floods, whereas river dolphin and caiman populations had stable abundances. Arboreal species, including, macaws, game birds, primates, felids, and other arboreal mammals had stable populations and were not affected directly by high floods. The drought of 2010 had the opposite effect: fish, waterfowl, and dolphin populations decreased, and populations of terrestrial and arboreal species remained stable. Ungulates and large rodents are important sources of food and income for local people, and large declines in these animals has shifted resource use of people living in the flooded forests away from hunting to a greater reliance on fish.  相似文献   
928.
Landscape‐scale alterations that accompany urbanization may negatively affect the population structure of wildlife species such as freshwater turtles. Changes to nesting sites and higher mortality rates due to vehicular collisions and increased predator populations may particularly affect immature turtles and mature female turtles. We hypothesized that the proportions of adult female and immature turtles in a population will negatively correlate with landscape urbanization. As a collaborative effort of the Ecological Research as Education Network (EREN), we sampled freshwater turtle populations in 11 states across the central and eastern United States. Contrary to expectations, we found a significant positive relationship between proportions of mature female painted turtles (Chrysemys picta) and urbanization. We did not detect a relationship between urbanization and proportions of immature turtles. Urbanization may alter the thermal environment of nesting sites such that more females are produced as urbanization increases. Our approach of creating a collaborative network of scientists and students at undergraduate institutions proved valuable in terms of testing our hypothesis over a large spatial scale while also allowing students to gain hands‐on experience in conservation science.  相似文献   
929.
Environmental Science and Pollution Research - Canadian Water Quality Index (CWQI) provides protection for freshwater life promoting healthy ecosystems and safeguarding human health. Biological...  相似文献   
930.
Recent increases in ivory poaching have depressed African elephant populations. Successful enforcement has led to ivory stockpiling. Stockpile destruction is becoming increasingly popular, and most destruction has occurred in the last 5 years. Ivory destruction is intended to send a strong message against ivory consumption, both in promoting a taboo on ivory use and catalyzing policy change. However, there has been no effort to establish the distribution and extent of media reporting on ivory destruction events globally. We analyzed media coverage of the largest ivory destruction event in history (Kenya, 30 April 2016) across 11 nation states connected to ivory trade. We used an online‐media crawling tool to search online media outlets and subjected 5 of the largest print newspapers (by circulation) in 5 nations of interest to content analysis. Most online news on the ivory burn came from the United States (81% of 1944 articles), whereas most of the print news articles came from Kenya (61% of 157 articles). Eighty‐six to 97% of all online articles reported the burn as a positive conservation action, whereas 4–50% discussed ivory burning as having a negative impact on elephant conservation. Most articles discussed law enforcement and trade bans as effective for elephant conservation. There was more relative search interest globally in the 2016 Kenyan ivory burn than any other burn in 5 years. Ours is the first attempt to track the reach of media coverage relative to an ivory burn and provides a case study in tracking the effects of a conservation‐marketing event.  相似文献   
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