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101.
Mercury Vapor Determination in Hospitals   总被引:1,自引:0,他引:1  
The measurements of metallic mercury vapor were carried out in seven local hospitals, where mercury-containing products are widely used, as well as in one residence to check effectiveness of decontamination after mercury spillage. Hopcalite as a solid sorbent was used in active and passive sampling methods, and mercury was analyzed by CV-AAS technique. Good agreement was found between results of mercury measurements using active samplers (pumped hopcalite adsorption tubes) and passive (diffusion) monitors applied in indoor atmosphere. The results indicated the presence of metallic mercury vaporization sources in the assessed hospital rooms but in the majority of cases mercury levels did not exceed 1 g/m3 i.e. Polish permissible concentration for residence. However, in some of the hospital rooms, elevated concentrations of mercury vapor were found and airborne levels of up to 13.9 g/m3 were recorded. Higher concentrations of mercury vapor were observed in autumn season when compared to summer.  相似文献   
102.
A Method of Mercury Removal from Topsoil Using Low-Thermal Application   总被引:3,自引:0,他引:3  
Mercury contamination in the environment is problematic due to the unusual physical properties and well-recognized toxicity of this common metal. The bioavailability of mercury depends strongly on its chemical speciation. Anthropogenic mercury and its compounds appear in soil as hot spots located close to industrial facilities that used or produced mercury. The nature of the chemical production process, transportation and disposal practices often determined the chemical composition and distribution of mercury in the surrounding soils. Current ex situ soil remediation methods are expensive, produce undesirable side effects to the environment and usually involve transportation of contaminated soil.In this project, sponsored by the U.S. Department of Energy, a low-cost, simple approach to removing mercury from soil was evaluated. The process uses low-temperature thermal desorption of volatile metallic mercury and its compounds, and subsequent vapor capture.The project consisted of laboratory and plot-scale experiments. The laboratory efforts evaluated theoretical calculations of mercury removal as a function of time and temperature. The plot-scale experiment was a practical application of the laboratory results. For both experiments, mercury-polluted soil was obtained from a chemical production facility located in southern Poland. In laboratory experiments, at temperature 373 K total mercury concentration decreased in soil by nearly 32%. In plot-scale experiments, at temperature 440 K, about 60–70% of total mercury was removed from the soil.At the end of the experiment, a test of soil biological activity was performed to check if the high temperature applied to the soil did not impair the soil growth properties. There was no negative effect of temperature found.  相似文献   
103.
The ASTM Method D4994-89 has been used in the United States for almost two decades to assess the virological quality of biosolids. However, the efficiency of this method for recovery of different enteric viruses has never been determined. The method was found to recover several different enteroviruses and adenovirus 2 with an efficiency ranging from 18.1 ± 5.5 to 24.6 ± 7.8%.  相似文献   
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Adam Rose   《Environmental Hazards》2007,7(4):383-398
Economic resilience is a major way to reduce losses from disasters. Its effectiveness would be further enhanced if it could be precisely defined and measured. This paper distinguishes static economic resilience—efficient allocation of existing resources—from dynamic economic resilience—speeding recovery through repair and reconstruction of the capital stock. Operational definitions are put forth that incorporate this important distinction. The consistency of the definitions is examined in relation to antecedents from several disciplines. The effectiveness of economic resilience is evaluated on the basis of recent empirical studies. In addition, its potential to be enhanced and eroded is analyzed in various contexts.  相似文献   
108.
Ground water beneath the U.S. Department of Energy Pantex Plant is contaminated with the high explosive RDX (hexahydro-1,3,5-trinitro-1,3,5 triazine). The USDOE Innovative Treatment and Remediation Demonstration (ITRD) program identified in situ oxidation by permanganate as a technology fit for further investigation. We evaluated the efficacy of KMnO(4) to transform and mineralize RDX by determining degradation kinetics and carbon mass balances using (14)C-RDX. Aqueous RDX solutions (2-5 mg L(-1)) and RDX-contaminated slurries (50% solids, w/v) were treated with KMnO(4) at 1000, 2000, 4000, and 20000 mg L(-1). Treating an aqueous RDX solution of 2.8 mg L(-1) with 20000 mg KMnO(4) L(-1) decreased RDX to 0.1 mg L(-1) within 11 d while cumulative mineralization proceeded for 14 d until 87% of the labeled carbon was trapped as (14)CO(2). Similar cumulative mineralization was obtained when Pantex aquifer material was included in the solution matrix. Other experiments using 4000 mg KMnO(4) L(-1) showed that initial RDX concentrations (1.3-10.4 mg L(-1)) or initial pH (4-11) had little effect on reaction rates. Attempts to identify RDX degradates and reaction products showed that N(2)O was a product of permanganate oxidation and constituted 20 to 30% of the N balance. Time-course measurements of a (14)C-RDX solution treated with KMnO(4) revealed few (14)C-labeled degradates but through liquid chromatography-mass spectrometry (LC-MS) analysis, we present evidence that 4-nitro-2,4-diaza-butanol is formed. Aquifer microcosm studies confirmed that the transformation products not mineralized by KMnO(4) were much more biodegradable than parent RDX. These results indicate permanganate can effectively transform and mineralize RDX in the presence of aquifer material and support its use as an in situ chemical oxidation treatment for the Pantex perched aquifer.  相似文献   
109.
Along term ecological research was carried out in a Hungarian oak forest, in "Bükk" National Park starting with 1972. During the faunistical studies 3,602 insect species and more than 200,000 individuals were collected. The dominant orders were Coleoptera (1,051 species), Lepidoptera (803 species), Hymenoptera (470 species) and Diptera (400 species). The relative species abundance (RSA) for all insects collected in all years of sampling period suggests a rather J shape curve than a not clear scaling property. This means that we were able to identify almost three quarters of the insect species from one ha European oak forest during the survey (from 1987 to 2003), and two third of the staphylinides expected. Considering the staphylinid fauna a total number of 160 species and 4,022 individuals were collected. The most widely occurring species in dominance order were: Ocypus biharicus, Pseudocypus mus, Atheta gagatina, Philonthus quisquiliarius, Oxypoda acuminate, Platydracus chalcocephalus, Atheta crassicomis, Latrimaeum atrocephalum, Haploglossa puncticollis, Philonthus succicola and Anotylus mutator. The pooled value of alpha diversity was 1.51. The Shannon-Weiner Index (H') was relatively high (3.29) in comparison with other studies.  相似文献   
110.
Uncommon heavy metals,metalloids and their plant toxicity: a review   总被引:4,自引:0,他引:4  
Heavy metals still represent a group of dangerous pollutants, to which close attention is paid. Many heavy metals are essential as important constituents of pigments and enzymes, mainly zinc, nickel and copper. However, all metals, especially cadmium, lead, mercury and copper, are toxic at high concentration because of disrupting enzyme functions, replacing essential metals in pigments or producing reactive oxygen species. The toxicity of less common heavy metals and metalloids, such as thallium, arsenic, chromium, antimony, selenium and bismuth, has been investigated. Here, we review the phytotoxicity of thallium, chromium, antimony, selenium, bismuth, and other rare heavy metals and metalloids such as tellurium, germanium, gallium, scandium, gold, platinum group metals (palladium, platinum and rhodium), technetium, tungsten, uranium, thorium, and rare earth elements yttrium and lanthanum, and the 14 lanthanides cerium, dysprosium, erbium, europium, gadolinium, holmium, lutetium, neodymium, promethium, praseodymium, samarium, terbium, thulium and ytterbium.  相似文献   
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