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931.
The number of environmental impact assessment (EIA) screenings in Denmark has increased dramatically since 2000. This is a consequence of increased pig production as well as the concentration of production on larger farms. In the same period, EIA rules have developed primarily due to an increased focus on the protection of groundwater and Natura 2000 sites. In particular, the implementation of Natura 2000 in Danish legislation has increased the demands on many farms. In its rulings on appealed cases, the Nature Protection Board of Appeal has strengthened its demands, and this is mirrored in screening practices. In this paper, the demands formulated in the guidelines of local authorities were analysed in order to investigate how the protection of groundwater, coastal waters, lakes and Natura 2000 sites develops through EIA screening. It is concluded that the level of protection has improved, and that the main cause for this is not EIA regulations as such, but the positive role which the implementation of the Natura 2000 objectives has played in this development. However, it was also found that the formulation of demands varies greatly between the counties, thus often resulting in ambiguity and leaving room for quite different practices in different counties. 相似文献
932.
Emission of the greenhouse gases nitrous oxide and methane from constructed wetlands in europe 总被引:1,自引:0,他引:1
Søvik AK Augustin J Heikkinen K Huttunen JT Necki JM Karjalainen SM Kløve B Liikanen A Mander U Puustinen M Teiter S Wachniew P 《Journal of environmental quality》2006,35(6):2360-2373
The potential atmospheric impact of constructed wetlands (CWs) should be examined as there is a worldwide increase in the development of these systems. Fluxes of N(2)O, CH(4), and CO(2) have been measured from CWs in Estonia, Finland, Norway, and Poland during winter and summer in horizontal and vertical subsurface flow (HSSF and VSSF), free surface water (FSW), and overland and groundwater flow (OGF) wetlands. The fluxes of N(2)O-N, CH(4)-C, and CO(2)-C ranged from -2.1 to 1000, -32 to 38 000, and -840 to 93 000 mg m(-2) d(-1), respectively. Emissions of N(2)O and CH(4) were significantly higher during summer than during winter. The VSSF wetlands had the highest fluxes of N(2)O during both summer and winter. Methane emissions were highest from the FSW wetlands during wintertime. In the HSSF wetlands, the emissions of N(2)O and CH(4) were in general highest in the inlet section. The vegetated ponds in the FSW wetlands released more N(2)O than the nonvegetated ponds. The global warming potential (GWP), summarizing the mean N(2)O and CH(4) emissions, ranged from 5700 to 26000 and 830 to 5100 mg CO(2) equivalents m(-2) d(-1) for the four CW types in summer and winter, respectively. The wintertime GWP was 8.5 to 89.5% of the corresponding summertime GWP, which highlights the importance of the cold season in the annual greenhouse gas release from north temperate and boreal CWs. However, due to their generally small area North European CWs were suggested to represent only a minor source for atmospheric N(2)O and CH(4). 相似文献
933.
Intensive manure application is an important source of diffuse phosphorus (P) pollution. Phosphorus availability from animal manure is influenced by its chemical speciation. The major objective of this study was to investigate the P speciation in raw and anaerobically digested dairy manure with an emphasis on the calcium (Ca) and magnesium (Mg) phosphate phases. Influent and effluent from an on-farm digester in Wisconsin were sampled and sieved, and the 25 to 53 microm size fraction was dried for X-ray powder diffraction (XRD) and P K-edge X-ray absorption near edge structure (XANES) analyses. Struvite (MgNH4PO4.6H2O) was identified in both the raw (influent) and anaerobically digested (effluent) manure using XRD. Qualitative analysis of P K-edge XANES spectra indicated that the Ca orthophosphate phases, except dicalcium phosphate anhydrous (DCPA) or monetite (CaHPO4), were not abundant in dairy manure. Linear combination fitting (LCF) of the P standard compounds showed that 57.0 and 43.0% of P was associated with DCPA and struvite, respectively, in the raw manure. In the anaerobically digested sample, 78.2% of P was present as struvite and 21.8% of P was associated with hydroxylapatite (HAp). The P speciation shifted toward Mg orthophosphates and least soluble Ca orthophosphates following anaerobic digestion. Similarity between the aqueous orthophosphate (aq-PO4), newberyite (MgHPO4.3H2O), and struvite spectra can cause inaccurate P speciation determination when dairy manure is analyzed solely using P K-edge XANES spectroscopy; however, XANES can be used in conjunction with XRD to quantify the distribution of inorganic P species in animal manure. 相似文献
934.
Kahl G Ingwersen J Nutniyom P Totrakool S Pansombat K Thavornyutikarn P Streck T 《Journal of environmental quality》2007,36(4):1205-1216
During recent decades, a change in land use in the mountainous regions of Northern Thailand has been accompanied by an increased input of agrochemicals. We identified lateral water flow and pesticide transport pathways and mechanisms in a Hapludult on a sloped litchi orchard in Northern Thailand. During two rainy seasons, two micro-trench experiments were performed at the plot scale (2 by 3 m). The first experiment was performed at the footslope of the orchard; the second was performed at a midslope position. Two salt tracers (bromide and chloride) and two pesticides {methomyl [S-methyl-N-(methylcarbamoyloxy)thioacetimidate] and chlorothalonil (2,4,5,6-Tetrachlor-1,3-benzdicarbonitril)} were applied in stripes parallel to the slope 150 and 300 cm away from the trench. At the trench, soil water was collected by wick samplers. Tensiometers and time-domain reflectometry probes were installed. At the end of the experiment, soil samples were taken and analyzed for residual concentrations of tracers and pesticides. Lateral subsurface flow of water occurred exclusively along preferential flow paths and was mainly observed at 0- to 30- and 60- to 90-cm depth. Lateral transport of pesticides was negligible, but both pesticides were found beneath the application area at 90 cm depth. Therefore, they may pose a groundwater contamination risk. The amount of wick flow and the location of interflow were mainly a function of rain amount and antecedent soil water suction. During dry periods, water flow was restricted to the topsoil. After heavy rain events and wet periods, interflow was mainly observed in the subsoil. The cumulative rain amount between samplings necessary to induce interflow was 20 mm. At the footslope, the interflow was seven times higher, and the network of water-bearing pores increased compared with the midslope position. 相似文献
935.
Uda M Sassa S Taniguchi K Nomura S Yoshimura S Kondo J Iskander N Zaghloul B 《Die Naturwissenschaften》2000,87(6):260-263
Some of the pigments painted on the Funerary Stele of Amenemhat (ca. 2000 B.C.) exhibited at the Egyptian Museum, Cairo and
on the walls of the Tomb of Userhat (ca. 1450 B.C.), a rock-cut tomb in Thebes, Egypt, were investigated in situ using both
a convenient home-made hand-held type of X-ray diffractometer and a commercial X-ray fluorescence spectrometer in a complementary
way under touch-free conditions. CaCO3 · 3MgCO3 (huntite) was found in the white-painted parts of these two ancient monuments. An arsenic (As)-bearing phase was detected
in the yellow-painted parts of the latter monument. The occurrence of huntite in Egypt has not been reported previously.
Received: 8 October 1999 / Accepted in revised form: 10 March 2000 相似文献
936.
937.
<正> 岩石化学分析结果的表征对于了解各种岩石之间的物质差别具有特别重要的意义。因为从这样的表征可以得出有关岩石成因的推论和有关岩石演化趋向的结论。显然,适用于得出这种推论和结论的各种物质参数之 相似文献
938.
Feigning death is a method of self-defense employed among a wide range of prey species when threatened by predator species. This paper reports on death-feigning behavior by the fire ant, Solenopsis invicta, during intraspecific aggression among neighboring fire ant workers. Days-old workers responded to aggression by death feigning, weeks-old workers responded by fleeing and months-old workers responded by fighting back. By feigning death, days-old workers were four times more likely to survive aggression than older workers. From a proximate perspective, retaliation by young workers against aggressive older workers is certain to fail. With their relatively soft exoskeleton, young workers would be prone to injury and death and unable to execute an effective attack of biting or stinging older workers with harder exoskeletons. From an ultimate perspective, death feigning allows young workers to survive and contribute to brood care and colony growth, both of which are essential to queen survival and fitness. 相似文献
939.
A pentachlorophenol (PCP) mineralizing bacterium was isolated from the secondary sludge of pulp and paper mill and identified
as Pseudomonas stutzeri strain CL7. This isolate used PCP as its sole source of carbon and energy and was capable of degrading this
compound as indicated by stoichiometric release of chloride and biomass formation. P. stutzeri (CL7) was able to mineralize a high
concentration of PCP (600 mg/L) than any previously reported Pseudomonad with PCP as sole carbon source. As the concentration
of PCP increased from 50 to 600 mg/L, the reduction in the cell growth was observed and the PCP degradation was more than 90%
in all studied concentrations. This isolate was able to remove 66.8% of PCP from the secondary sludge of pulp and paper mill when
supplemented with 100 mg/L of PCP and grown for two weeks. This study showed that the removal e ciency of PCP by CL7 was
found to be very e ective and can be used in PCP remediation of pulp paper mill waste in the environment. 相似文献
940.
前言 根据契利安—安第斯(Chilcan And-es)地区近年来的地球化学研究结果,Arm-brust 等(1971)和 Oyarzun(1971,1974认为 Rb 和 Sr 是产于蚀变安山岩和玄武岩中斑岩铜矿床的潜在指示剂,但后者发现这对于蚀变花岗岩侵入体作地球化学对比不太适合。Warren 等(1974)提出把 Ba 和 Sr 作为寻找火山岩中矿体的地球化学手段。这些应用的地球化学和地质学根据与斑岩铜矿床有关的某些类型的热液蚀变中 Rb 的普遍富集和 Sr 的减少有关。 相似文献