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161.
Alamgir Hossain Jamal Naser Monzur Alam Imteaz 《Environmental Modeling and Assessment》2011,16(4):359-367
This paper presents comprehensive 3D numerical investigations on depositions of particles flowing through a horizontal pipe
loop consisting of four bends. The multiphase mixture model available in FLUENT 6.2 was used in this study. In this numerical
simulation, five different particle sizes have been used as secondary phases to calculate real multiphase effect in which
inter-particle interaction has been considered. The deposition of particles along the periphery of the pipe wall was investigated
as a function of particle size and fluid velocity. The simulations showed that near the upstream of the bends, maximum particle
concentration occurred at the bottom of the pipe. However, downstream the bends, the maximum particle concentration occurred
at an angle of 60° from the bottom. The larger particles clearly showed deposition near the bottom wall except downstream.
As expected, the smaller particles showed less tendency of deposition and lesser at higher velocity. This numerical investigation
showed qualitative agreement with the experiments conducted by Commonwealth Scientific and Industrial Research Organisation,
Melbourne team for similar conditions. 相似文献
162.
Konstantinos C. Makris Dibyendu Sarkar Jason Salazar Pravin Punamiya Rupali Datta 《Environmental science and pollution research international》2010,17(1):195-202
Background, aim, and scope
Alum (aluminum sulfate) is the currently preferred chemical amendment for phosphorus (P) treatment in poultry litter (PL). Aluminum-based drinking-water treatment residuals (Al-WTRs) are the waste by-product of the drinking-water treatment process and have been effectively used to remove P from aqueous solutions, but their effectiveness in PL water extracts has not been studied in detail. Elevated cost associated with alum could be minimized by using the equally effective WTRs to remove soluble P from PL, and they can be obtained at a minimal cost from drinking-water treatment plants. 相似文献163.
Leila Mehrparvar Siyamak Safapour Mousa Sadeghi-Kiakhani Kamaladin Gharanjig 《Environmental Chemistry Letters》2016,14(4):533-539
The classical use of synthetic dyes is causing issues of environmental pollution and heath risk. As a consequence natural dyes are gaining interest, but the use of natural dyes still includes toxic reagents such as metals as mordants and acids to enhance color and yield. Therefore, we designed a new chitosan-polypropylene imine dendrimer hybrid at 0–2000 mg/L to treat wool before dyeing with cochineal. We compared dye exhaustion, color depth, color characteristics, and color fastness of the new process with dyed pristine and metal mordanted wool. Results show that wool pretreatment improved dye exhaustion from 48 to 88 %, shifted saturation point toward lower dye concentration from 3000 to 1000 mg/L, and improved color depth from 13.68 for pristine wool and 15.17 for metal mordanted wool to 23.89 for the new process. 相似文献
164.
International environmental agreements (IEAs) can coordinate abatement of transboundary pollutants. This paper investigates
how heterogeneous countries facing a stock pollutant might structure such an agreement. In particular, we examine how an IEA
might be implemented with a set of monetary transfers. The focus is on transfers that are time invariant, linear in emissions,
and consistent with budget balance. There is a range of such schemes that would induce efficient emissions. We provide a simple
and intuitive characterization of these penalties and describe how specific proposals might be chosen in order to facilitate
compliance and implementation. Our proposals are illustrated with a simple example. We show that heterogeneity reduces the
scope for penalty schemes to jointly satisfy desirable properties. 相似文献
165.
Kazuharu Yoshizuka Syouhei Nishihama Hideki Sato 《Environmental geochemistry and health》2010,32(4):297-302
The objective of this study was to survey the cation and anion contents of geothermal waters to gather fundamental information
on geographical variations. Sixteen sites in hot spring areas on the island of Kyushu in Japan were studied. The study focused
on the arsenic content of the samples. Very high arsenic concentrations (more than 0.1 mg/l) were detected in most of the
geothermal waters sampled. High contents of boron and fluoride (more than 1.0 mg/l) were also detected in some samples. Arsenic
removal was performed on a laboratory scale using columns packed with a magnetite-type adsorbent. The reduction of arsenic
contamination to a concentration of less than 0.01 mg/l could be achieved in the early stages of adsorption (bed volume = 200). 相似文献
166.
167.
This work is a part of a wider study involving the economic and environmental implications of managing construction and demolition waste (CDW), focused on the operation of a large scale CDW recycling plant. This plant, to be operated in the Lisbon Metropolitan Area (including the Setúbal peninsula), is analysed for a 60 year period, using primary energy consumption and CO2eq emission impact factors as environmental impact performance indicators.Simplified estimation methods are used to calculate industrial equipment incorporated, and the operation and transport related impacts. Material recycling – sorted materials sent to other industries, to act as input – is taken into account by discounting the impacts related to industrial processes no longer needed.This first part focuses on calculating the selected impact factors for a base case scenario (with a 350 tonnes/h installed capacity), while a sensitivity analysis is provided in part two. Overall, a 60 year global primary energy consumption of 71.4 thousand toe (tonne of oil equivalent) and a total CO2eq emission of 135.4 thousand tonnes are expected. Under this operating regime, around 563 thousand toe and 1465 thousand tonnes CO2eq could be prevented by replacing raw materials in several construction materials industries (e.g.: ferrous and non-ferrous metals, plastics, paper and cardboard). 相似文献
168.
Jesús M. Avilés Deseada Parejo Tomás Pérez-Contreras Carlos Navarro Juan J. Soler 《Die Naturwissenschaften》2010,97(2):181-186
A considerable number of bird species carry feathers to their nests. Feathers’ presence in the nests has traditionally been
explained by their insulating properties. Recently, however, it has been suggested that feathers carried to the nests by females
of the spotted starling (Sturnus unicolor L.) could have an ornamental function based on their ultraviolet (300–400 nm) and human-visible longer wavelength (400–700 nm)
coloration. In our population, 95.7% of feathers found inside next-boxes occupied by nesting starlings were rock dove fly
feathers. Of these feathers, 82.7% were naturally positioned with their reverse side oriented toward the entrance hole and
42.4% of all found feathers were situated within the nest-cup. Here we experimentally assess the signaling function of ultraviolet
coloration of feathers in nests of spotless starlings by providing nests with a number of pigeon flight feathers that were
respectively treated on their obverse, reverse, both, or neither side with a UV blocker. Starlings placed 42.5% of the experimental
feathers in the nest-cup irrespective of the UV block treatment. Orientation of feathers toward the entrance hole was not
related with their ultraviolet radiation. However, feathers placed within the nest-cup were more likely found with their reverse
side oriented toward the entrance hole confirming our correlative findings. These results suggest a minor role of ultraviolet
coloration on feather location by spotless starlings. 相似文献
169.
The Role of Disaggregation of Asset Values in Flood Loss Estimation: A Comparison of Different Modeling Approaches at the Mulde River,Germany 总被引:3,自引:0,他引:3
Anja Wünsch Ulrich Herrmann Heidi Kreibich Annegret H. Thieken 《Environmental management》2009,44(3):524-541
In loss estimation there is a spatial mismatch of hazard data that are commonly modeled on an explicit raster level and exposure
data that are often available only for aggregated administrative units. Usually disaggregation methods that use ancillary
information to distribute lumped exposure data in a finer spatial resolution help to bridge this gap. However, the actual
influence of different mapping techniques and ancillary data on the final loss estimation has not been analyzed yet. In this
paper three methods are applied to disaggregate residential building assets using two kinds of land use/land cover (LULC)
data. The resulting disaggregated assets are validated and compared using census data of the residential building number on
the community and constituency level. In addition, the disaggregated assets are taken to estimate residential building losses
due to the flood in August 2002 in 21 municipalities on the River Mulde in Saxony, Germany. Losses are calculated with the
help of four loss models. In general, disaggregation helps to decrease the error variance within the loss estimation. It must,
however, be stated that the application of sophisticated disaggregation methods does not lead to significant improvements
compared to the straightforward binary method. Therefore more effort should instead be put into the provision of high-resolution
LULC data. Finally, the remaining uncertainties in loss estimation are high and demand further improvements in all modeling
aspects. 相似文献
170.