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171.
Mosaicism for the Wolf-Hirschhorn syndrome, del(4)(p16), is extremely rare and has not been reported in association with a numerical chromosome abnormality. We report the prenatal diagnosis of mosaic del(4)(p16) and non-mosaic trisomy 21 in a 16-week female fetus. The pregnancy ended in spontaneous abortion at 34 weeks secondary to fetal demise. The fetus had features of both 4p – and trisomy 21.  相似文献   
172.
    
Genetic counseling for prenatal diagnosis of autosomal trisomy is complex because of the uncertainty of outcome, which is important for management decisions. Compilation of cases of prenatally diagnosed autosomal trisomies in amniocytes has been done previously in an attempt to elucidate the clinical phenotype of these pregnancies. It has been greater than a decade since these studies were completed. To update this work, we reviewed cases reported in the literature since that time. These cases are correlated with the prior reports to increase knowledge about outcomes and to hopefully improve the data available for genetic counseling. The risk of abnormal outcome can be summarized as: very high risk (>60%) for 47,+2/46; 47,+9/46; 47,+16/46; 47,+20/46; and 47,+22/46; high risk (40–59%) for 47,+5/46; 47,+14/46; and 47,+15/46; moderately high risk (20–39%) for 47,+7/46 47,+12/46; and 47,+17/46; moderate risk (up to 19%) for 47,+6/46 and 47,+8/46, and none were low risk. 47,+6/46 was originally indeterminate, 47,+7/46 was originally moderate risk, 47,+9/46 was originally high risk, and 47,+17/46 was originally low risk. © 2015 John Wiley & Sons, Ltd.  相似文献   
173.
Independent teams undertook environmental monitoring of particular concentrations of major construction projects forming part of Hong Kong’s U.S. $20 billion airport infrastructure programme located in dense urban areas. The team combination of environmental specialists with experienced civil engineers enabled pragmatic mitigation measures to be developed and accepted by the construction personnel with the result that potentially significant adverse impacts were averted. The authors discuss the mechanism and success of this innovative approach.  相似文献   
174.
Persistent Organic Pollutants (POPs) threaten human health and the global environment. Recognizing their dangers many countries began to limit or ban POPs production, use, and release in the 1990s. Eventually the Stockholm Convention on POPs, was adopted in 2001 and entered into force in 2004. The Global Environment Facility (GEF) provides financial support to developing country Parties for the implementation of the Stockholm Convention. The GEF’s POPs investment portfolio focuses on: 1) strengthening the capacity of developing country Parties to implement the Stockholm Convention; 2) establishing and supporting partnerships to develop and implement National Implementation Plans (NIPs), and 3) demonstrating and deploying best technologies and practices to reduce POPs emission, including development of safe alternatives. Since 2001 the GEF has committed US$568.8 million to POPs projects and leveraged some US$1474.5 million in co-financing from partners in the public and private sectors, bringing the total value of the GEF POPs portfolio to over US$2 billion. With GEF support, 108 developing country Parties have developed their NIPs. The GEF also financed 109 projects for the implementation of the Convention. Upon completion, these GEF POPs investments will contribute to the disposal of more than 70,000 tons of Polychlorinated Biphenyls (PCBs) oil, contaminated equipments, and waste, more than 40,000 tons of obsolete POPs pesticides and associated waste, and reducing dioxin/furan and mercury emission by introducing environmentally sound technologies and best practices. This paper summarizes: 1) direct and indirect GEF investments to support the goals of the Stockholm Convention; 2) investment case studies on PCB, DichloroDiphenylTrichloroethane (DDT), chlordane and mirex, medical waste, obsolete POPs and engaging civil society; and 3) lessons learned in terms of GEF financing strategies, best technologies and environmental practices to address POPs.  相似文献   
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177.
Abstract: Previous investigations observed significant seepage losses from the Rio Grande to the shallow aquifer between Socorro and San Antonio, New Mexico. High‐resolution telescopic modeling was used along a 10‐km reach of the Rio Grande and associated drains and canals to evaluate several management alternatives aimed at improving river conveyance efficiency. Observed data consisted of ground‐water and surface‐water elevations, seepage rates along the Rio Grande and associated canals and drains, and borehole geology. Model calibration was achieved by adjusting hydraulic conductivity and specific storage until the output matched observed data. Sensitivity analyses indicated that the system was responsive to changes in hydrogeologic properties, especially when such alterations increased vertical connectivity between layers. The calibrated model predicted that removal of the low flow conveyance channel, a major channel draining the valley, would not only decrease river seepage by 67%, but also decrease total flow through the reach by 75%. The decreased flow through the reach would result in increased water logging and an average increase in ground‐water elevations of 1.21 meter. Simulations of the system with reduced riparian evapotranspiration rates or a relocated river channel also predicted decreased river seepage, but to a much lesser degree.  相似文献   
178.
Stone, Wesley W. and Robert J. Gilliom, 2012. Watershed Regressions for Pesticides (WARP) Models for Predicting Atrazine Concentrations in Corn Belt Streams. Journal of the American Water Resources Association (JAWRA) 48(5): 970‐986. DOI: 10.1111/j.1752‐1688.2012.00661.x Abstract: Watershed Regressions for Pesticides (WARP) models, previously developed for atrazine at the national scale, are improved for application to the United States (U.S.) Corn Belt region by developing region‐specific models that include watershed characteristics that are influential in predicting atrazine concentration statistics within the Corn Belt. WARP models for the Corn Belt (WARP‐CB) were developed for annual maximum moving‐average (14‐, 21‐, 30‐, 60‐, and 90‐day durations) and annual 95th‐percentile atrazine concentrations in streams of the Corn Belt region. The WARP‐CB models accounted for 53 to 62% of the variability in the various concentration statistics among the model‐development sites. Model predictions were within a factor of 5 of the observed concentration statistic for over 90% of the model‐development sites. The WARP‐CB residuals and uncertainty are lower than those of the National WARP model for the same sites. Although atrazine‐use intensity is the most important explanatory variable in the National WARP models, it is not a significant variable in the WARP‐CB models. The WARP‐CB models provide improved predictions for Corn Belt streams draining watersheds with atrazine‐use intensities of 17 kg/km2 of watershed area or greater.  相似文献   
179.
Validation of a hybrid life-cycle inventory analysis method   总被引:2,自引:0,他引:2  
The life-cycle inventory analysis step of a life-cycle assessment (LCA) may currently suffer from several limitations, mainly concerned with the use of incomplete and unreliable data sources and methods of assessment. Many past LCA studies have used traditional inventory analysis methods, namely process analysis and input-output analysis. More recently, hybrid inventory analysis methods have been developed, combining these two traditional methods in an attempt to minimise their limitations. In light of recent improvements, these hybrid methods need to be compared and validated, as these too have been considered to have several limitations. This paper evaluates a recently developed hybrid inventory analysis method which aims to improve the limitations of previous methods. It was found that the truncation associated with process analysis can be up to 87%, reflecting the considerable shortcomings in the quantity of process data currently available. Capital inputs were found to account for up to 22% of the total inputs to a particular product. These findings suggest that current best-practice methods are sufficiently accurate for most typical applications, but this is heavily dependent upon data quality and availability. The use of input-output data assists in improving the system boundary completeness of life-cycle inventories. However, the use of input-output analysis alone does not always provide an accurate model for replacing process data. Further improvements in the quantity of process data currently available are needed to increase the reliability of life-cycle inventories.  相似文献   
180.
Irreversible environmental changes are occurring along the Colorado River in the Grand Canyon as a result of regulation of the river flow by the Glen Canyon Dam. The questions of primary importance in managing this great natural resource are 1) in what manner and how rapidly are the physical and ecological adjustments taking place, and 2) is the increased use of the river for recreational boating contributing to the degradation? Human use along the Colorado River is limited, for the most part, to the relic, pre-dam fluvial deposits colloquially called “beaches.” With the new river regime these deposits are positioned well above the present high-water stage, 27,000 cubic feet/second (cfs), or 765 cubic meters/second (cms), so they are not replenished periodically as they were prior to construction of the dam in 1963. The dominant natural processes now are aeolian sand transport and mass wasting. The float-trip passengers use the river beaches for hiking, camping, and. lunch stops. At the most desirable sites thirty to forty people camp on the beaches each night over a four to five month season. Human impact includes incorporation of campsite litter, burial of chemically treated waste, and the direct stress associated with people walking on the vegetation and unstable sedimentary deposits. Results of our investigations indicate that the rate of degradation at the most heavily used sites exceeds the capacity of aeolian processes to reestablish natural landscapes. Therefore, careful management of float trjps is needed if these environments are to be maintained in a natural state rather than a “sand-box” state.  相似文献   
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