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191.
Patancheru and Bolaram are satellite industrial towns nearHyderabad with over 300 large andmedium scale pharmaceutical, heavy engineering, paints, paperand chemical factories. The industriesof the area generate a cumulative 8 × 106 l/day ofeffluents which are being directly dischargedon to surrounding land, irrigation fields, and surface waterbodies which finally enter into theNakkavagu River a tributary of the Manzira River. The presentstudy on abundance and distributionpattern of toxic trace elements indicates the quantitativeaspect of pollution in the Nakkavagu Basin.Migration patterns drawn for TDS, toxic elements such as Cu,As, Se, Zn, B, Cr and iron indicate thatpollutants discharged by the industries are entering thesurface and groundwater system (aquifers) andare also migrating towards the Manzira River furtherdeteriorating the entire hydrological setup of the area.Entry and dispersion of pollutants in the hydrological systemis shown by distribution diagrams. Aconservative estimate indicates that the effect of pollutantson the agricultural lands and water bodiesextends 0.25 to 0.5 km to either side of the Nakkavagu Riverover a length of 25 km. In addition tothis, the movement of pollutants with ground water in thedownstream direction worsened thehydrological system and increased the possibility ofgeo-accumulation of pollutants in biota. Openwells, dug wells and tanks have become useless and redundantas the concentrations of Cu, Se, As,B, Cr and Fe have increased to 5 to 10 times the permissiblelimits. Several villages have beenaffected by the toxic pollutants in the area. The groundwatersystem is polluted over a large area asshown in elemental migration diagrams and is not potable.Tentatively an area of 20 sq km can becategorized as the worst affected by various pollutants. 相似文献
192.
基于在稀硫酸介质中,银催化过二硫酸铰氧化铬(Ⅲ)的反应,以硫酸钡在乙酸钠介质中共沉淀Cr(6+),微孔滤膜过滤制成薄样,XRFA法测定,本文建立催化XRFA法测定痕量银。 相似文献
193.
Elemental Analysis of Water and Sediments by External Beam Pixe Part 3: Axios (Vardar) River, Greece
E. Papadopoulou-mourkidou G. A. Mourkides A. A. Katsanos P. K. Kakanis 《Chemistry and Ecology》1986,2(4):335-350
The Axios (Vardar) River originates from the south west part of Yugoslavia, transverses Greece, and discharges into the Thermaikos bay in the north Aegean Sea.
The proton induced X-ray emission (PIXE) method with external beam was used for the elemental analysis of water and sediment samples, while measurements of water temperature, dissolved oxygen content, conductivity, pH, and the water flow were made in situ. Water samples were also analysed for total phosphates, nitrates, chlorophyll, and BOD. The data collected for a 16-month period indicate that the Axios River is polluted as far as the metal content is concerned; its primary productivity is low and it is slightly enriched during its course into the Greek territory. 相似文献
The proton induced X-ray emission (PIXE) method with external beam was used for the elemental analysis of water and sediment samples, while measurements of water temperature, dissolved oxygen content, conductivity, pH, and the water flow were made in situ. Water samples were also analysed for total phosphates, nitrates, chlorophyll, and BOD. The data collected for a 16-month period indicate that the Axios River is polluted as far as the metal content is concerned; its primary productivity is low and it is slightly enriched during its course into the Greek territory. 相似文献
194.
I. V. Shtangeeva 《Chemistry and Ecology》1995,11(2):85-95
Neutron activation analysis was used for the determination of the elemental composition of different plants and soils. Variations in concentrations of elements during the day were found. Mean concentrations, standard deviations and relationships between elements in soils and different parts of plants were studied. It was shown that the behaviour of chemical elements in samples from urban and unpolluted areas have significant differences. 相似文献
195.
Sediments collected from Tap Mun (within Tolo Harbour) and Yim Tin Tsai (outside Tolo Harbour) were extracted sequentially
and the copper, cadmium, and chromium contents were determined. Total contents of copper, cadmium, chromium, and arsenic were
also detected by acid digestion. The level of heavy metal extracted was higher in sequential extraction (which extracted all
forms of metal ions) than total acid digestion. Among the four heavy metals studied, only copper showed a significantly higher
(P<0.001) level in samples collected from Yim Tin Tsai (16.10 mg/kg) than that from Tap Mun (3.19 mg/kg). Such a difference
in copper level is mainly attributed to the significantly higher (P<0.05) levels of copper in the organic, carbonate, and sulfide forms, whereas there was no significant difference (P>0.05) in the exchangeable and sorbed forms.
Green-lipped mussel (Perna viridis) samples collected from the two sites were dissected into seven parts (gill, byssus, siphon, shell, digestive gland, soft
tissue, and adductor muscle) and the concentrations of copper, cadmium, chromium, and arsenic were measured. The highest concentration
of copper was obtained in the byssus. A higher concentration of copper was also noted in the mussels collected from Yim Tin
Tsai than those collected from Tap Mun. No specific trend was revealed for the other metals tested. Chromium and arsenic concentrations
were found to be independent of the body size of the mussels. Copper had a lower concentration in larger mussels and cadmium
level was found to decrease with size. In addition, the mussels collected from Tap Mun were much larger than those collected
from Yim Tin Tsai. 相似文献
196.
Probability plots of trace element concentrations may be used to partition, or segregate, sample data into its constituent
populations. Two populations are typically present in data from sites requiring remedial action, one representing clean, uncontaminated
soil or sediment (background) and the other representing contaminated ground. The use of such plots in the analysis and evaluation
of environmental data permits a statistical characterization of the background populations, from which defensible cleanup
criteria may be developed. These criteria will be environmentally conservative, yet will minimize the amount of soil removed
in a remedial action. An example is given from a successful cleanup of a surface impoundment. 相似文献
197.
198.
Qin Shao Machelle D. Wilson Christopher S. Romanek Keith A. Hobson 《Environmental and Ecological Statistics》2004,11(3):323-337
A temporal record of environmental conditions is often contained within accretionary biological tissue. These records can provide knowledge of the environmental conditions that existed at the time the tissue was formed. In this study, we look at trace element concentrations and isotopic ratios of carbon and nitrogen as contained in baleen from bowhead whales in the eastern and western Arctic Ocean. Time series techniques, including maximum likelihood method and likelihood ratio tests, are applied to analysis of data and inference about their mean structures. 相似文献
199.
本文讨论了川西前陆盆地气田区上三叠统和侏罗系地层水K+ +Na+ 、Ca2 + 、Mg2 + 、Br-与Cl-离子、矿物 (胶结物和充填物 )碳氧同位素和水的氢氧同位素成分组成以及相互关系。气田区上三叠统流体来源以地层海陆相沉积物质为主 ,并与渗流水混合 ,形成“下部流体”。有气藏的侏罗系内流体 (称“上部流体”)与“下部流体”的水化学和同位素组成相近 ,且具有同一演化趋势 ,表明它来源于下部流体并与侏罗系层内的渗流水发生过混合作用。本文提出该气田流体具跨层流动、二次混合演化特征 ,认为大规模的流体对流混合促进了上三叠统内天然气的运移聚积 ,在三叠系内有利构造圈闭中形成原生或残留气藏并向上运移 ,在侏罗系内有利圈闭中形成“次生”气藏。 相似文献
200.
Ten male buffalo calves were randomly allotted into five groups of two each. Four groups were fed with cadmium, molybdenum, cadmium-molybdenum, and copper-cadmium-molybdenum respectively for 130 days to determine the elements' metabolic interactions in calves. These results indicated that cadmium and molybdenum could increase the accumulation of molybdenum and cadmium in liver and kidneys in buffalo calves, but copper could not. reduce to normal the levels of molybdenum and cadmium in liver and kidneys caused by cadmium-molybdenum. In addition, we found the copper concentrations in liver and kindeys was significantly greater in treatment calves than in controls. 相似文献