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801.
A prenatal diagnosis was carried out on a 9-week-old fetus at risk for autosomal dominant polycystic kidney disease (ADPKD). Ten members of the family were previously typed using five DNA markers linked to the PKD1 locus on chromosome 16, and one marker linked to the putative PKD2 locus on chromosome 2. The polymerase chain reaction (PCR) was used to amplify the D16S125 locus. Pairwise and multipoint lod scores indicated that the family was most likely segregating a PKD1 mutation. The fetus inherited the disease haplotype from the affected parent. Diagnostic accuracy was greater than 99 per cent, taking into account the possibility of genetic heterogeneity.  相似文献   
802.
803.
Seasonal variation of above ground and belowground biomass of Spartina maritima and Halimione portulacoides, decomposition rates of belowground detritus in litterbags, and carbon partitioning in plant components and sediments were determined in two Tagus estuary marshes with different environmentalconditions. Total biomass was higher in the saltier marsh from 7,190 to 6,593 g m-2 dw and belowground component contributed to more than 90%. Litterbag experiment showed that 30 to 50% of carbonis decomposed within a month (decomposition rate from 0.024 to 0.060 d-1). Slower decomposition in subsequent periods agrees with accumulation of carbon concentration in sediment. Atmospheric carbon annually transferred to the plant belowground biomass is stored more efficiently in sediments of Corroios than Pancas.  相似文献   
804.
Summary Tamarins of the genus Saguinus feed on a wide range of arthropods and small vertebrates, which compose a critical component of their diet. This paper examines the foraging patterns and capture success of the Avila-Peres saddle-back (S. fuscicollis avilapiresi) and the red-capped moustached tamarin (S. mystax pileatus) in very stable mixed-species groups, and whether and how any foraging benefits for either species resulted from their association. Moustached tamarins actively searched for prey items which were mainly well exposed on the midstorey foliage. Saddle-back tamarins, on the other hand, foraged at lower heights, largely by manipulating a variety of microhabitats potentially concealing embedded prey. The foraging activity of the numerically dominant and larger-bodied moustached tamarins often resulted in prey items escaping to lower substrates, usually the forest leaf-litter. The beating effect of this species substantially facilitated captures of large, mobile prey items by saddle-backs, which were highly adept at locating and retrieving flushed prey. It is estimated that, while saddle-backs obtained 66–73% of their prey biomass from flushed items, this proportion was substantially lower (2–9%) for moustached tamarins. Commensal insectivory appears to involve a highly asymmetric benefit to saddle-backs, and a low cost to moustached tamarins, which partly explains the stability of mixed-species groups. Correspondence to the present address  相似文献   
805.
806.
The Tinto and Odiel rivers are seriously affected by acid mine drainage (AMD) from the long-term mining activities in Iberian Pyrite Belt (IPB). As a consequence, the Huelva estuary is heavily contaminated by metals and metalloids. This study presents an estimation of the seasonal variation, and the dissolved contaminant load transported by both rivers from February 2002 to September 2004. Besides, toxicity and bioaccumulation tests with the sediments of the estuary have been conducted in order to measure the mobility of the toxic metals. Results show that the Tinto and Odiel rivers transport enormous quantities of dissolved metals to the estuary: 7900 t yr(-1) of Iron (Fe), 5800 t yr(-1) Aluminium (Al), 3500 t yr(-1) Zinc (Zn), 1700 t yr(-1) Copper (Cu), 1600 t yr(-1) Manganese (Mn) and minor quantities of other metals and metalloids. These values represent 37% of the global gross flux of dissolved Zn transported by rivers in to the ocean, and 15% of the global gross flux of dissolved Cu. These metals and metalloids usually sink in the estuarine sediments due to pH and salinity changes. The increase of salinity in the estuary favours the adsorption and trapping of metals. For this reason, the mobility and bioavailability of metals such as Zn, Cd and Cu is higher in sediments located in the area of fresh water influence that in sediments located in the marine influenced area of the estuary, showing a higher percentage of fractionation and bioaccumulation of these metals in the station influenced by the fresh water environment.  相似文献   
807.
Because of the lack of reports, the base levels of microbial contamination on stored fuels are unknown in tropical regions and it is unclear whether these levels have some influence on fuel quality parameters. Therefore, fungal quality in automobile fuels stored across Costa Rican territory was evaluated during two years according to the standard ASTM D6974-04. For a total of 96 samples, counts and identification of molds and yeasts were performed on regular gas, premium gas and diesel taken from the bottom and superior part of the container tanks. The highest contamination was found on the bottom of the tanks, where an aqueous phase was usually identified, showing populations over the ones present in the hydrocarbon itself (up to 108 CFU/L). Diesel was the most contaminated fuel (up to 107 CFU/L); however, an alteration on the physicochemical parameters was not observed in any kind of fuel. Seventy-five mold strains were isolated, Penicillium sp. being the most common genus (45.8% of the samples), and ten yeast strains, from the genera Candida sp. and Rhodotorula sp. Four of the yeasts were able to grow on diesel as the sole carbon source, at concentrations ranging from 0.5% to 25%. Increasing the frequency of tank cleaning, adding antimicrobial agents and monitoring microbial populations are recommended strategies to improve microbial quality of stored fuels.  相似文献   
808.
Adenoviruses are a highly important public health issue, since they are among the most persistent and ubiquitous viruses present in water and associated with a variety of clinical manifestations. The aim of this study was to use molecular techniques for the detection of adenovirus in public and recreational water supplies in Goiania, Brazil. From December 2007 to November 2008, 54 water samples were collected in 5 different sites in 2 lakes and 2 rivers of the city. The samples were filtered in a positively charged nylon membrane, and the DNA was extracted using the phenol–chloroform–isoamyl alcohol method. Semi-nested PCR was used to detect adenovirus DNA, and sequence analysis of the semi-nested PCR products was performed to identify the recovered viruses. Adenovirus DNA was detected in 43% (24 of 54) of samples collected. Considering all examined sites, MP1 presented the highest occurrence of adenovirus (6 positive from 10 collected samples), followed by MP2 (3 positive from 6 collected samples), JL (10 positive from 21 collected samples), VB (3 positive from 9 collected samples), and BB (2 positive from 8 collected samples), respectively. The methodology employed proved to be feasible, fast, low-cost, and suitable to be used as screening approach on adenovirus detection in water for public sanitation companies.  相似文献   
809.
Protected Areas and Conservation of Biodiversity in the Tropics   总被引:7,自引:0,他引:7  
Abstract: We compared deforestation rates and the extent of fragmentation inside and outside protected areas in the Sarapiquí region of Costa Rica. We determined deforestation rates using remotely sensed images with supervised classification. We georeferenced the processed images and then transformed them to vector format for final mapping and parameter quantification. The deforestation rate in protected areas was low and declined sharply from 0.56% annually between 1976 and 1986 to 0.16% from 1991 to 1995. Outside the protected areas, the rate decreased from 3.6% in 1976–1986 to 2.8% in 1986–1991, but it increased again to 3.2% in 1991–1995. Fragmentation outside the protected areas increased considerably: the number of patches increased from 537 in 1976 to 1231 in 1996, while during the same period the average size of patches decreased from 0.95 to 0.25 km2. Forest landscapes in the Sarapiquí region are likely to lose considerable biodiversity because of the past forest loss and fragmentation even without further increases in deforestation and fragmentation.  相似文献   
810.
This paper includes the proposals made in the report “Basis for a National Strategy for Coastal Zone Management” prepared for the Portuguese Ministry of Environment, Territorial Planning and Regional Development. The final version of that report was presented in June 2006. This paper describes a theme framework followed by a discussion of concepts. Nine Primary Principles, eight Principal Objectives, and 37 Strategic Options for an Integrated Coastal Zone Management are then presented. These Strategic Options are set hierarchically according to their sequential priority, identifying the dominant types of Associated Measures. The analysis of these arrives at a set of Structural Measures, which interlink and aggregate various actions and propose a new method of integrated management for the coastal zone, which includes the “Legal Basis of Coastal Zone”; the Organization System; the Action Plan and Monitoring.  相似文献   
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