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21.
A single base substitution in exon 10 of the glucocerebrosidase gene was detected in families affected by Gaucher disease (GD) type III. This mutation, which results in the substitution of proline for leucine in position 444 of glucocerebrosidase, has been shown to result in type III GD in a Swedish population. Three fetuses at risk for GD type III were diagnosed as homozygous for the mutation and the pregnancies were terminated. In a fourth pregnancy, one parent was excluded as being a carrier and the risk of having a child affected by GD was ignored. Direct analysis of common mutations causal to GD is now available and improves prenatal diagnosis in families where the molecular defect has been characterized.  相似文献   
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23.
The terrestrial chapter of the Circumpolar Biodiversity Monitoring Programme (CBMP) has the potential to bring international multi-taxon, long-term monitoring together, but detailed fundamental species information for Arctic arthropods lags far behind that for vertebrates and plants. In this paper, we demonstrate this major challenge to the CBMP by focussing on spiders (Order: Araneae) as an example group. We collate available circumpolar data on the distribution of spiders and highlight the current monitoring opportunities and identify the key knowledge gaps to address before monitoring can become efficient. We found spider data to be more complete than data for other taxa, but still variable in quality and availability between Arctic regions, highlighting the need for greater international co-operation for baseline studies and data sharing. There is also a dearth of long-term datasets for spiders and other arthropod groups from which to assess status and trends of biodiversity. Therefore, baseline studies should be conducted at all monitoring stations and we make recommendations for the development of the CBMP in relation to terrestrial arthropods more generally.  相似文献   
24.
Alumina used in the production of primary aluminium contains Be which partly vaporises from the cryolite bath into the workroom atmosphere. Since Be may be toxic at lower exposure levels than previously thought, the personal exposure to Be among workers in 7 Norwegian primary smelters has been assessed. In total, 480 personal Respicon? virtual impactor full shift air samples have been collected during 2 sampling campaigns and analysed for water soluble Be, Al and Na using inductively coupled plasma optical emission spectrometry. In addition, water soluble F(-) has been measured by ion chromatography. The Be air concentrations in the inhalable, thoracic and respirable aerosol fractions have been calculated. The Be concentrations in the inhalable aerosol fraction vary between the different smelters. The highest GM concentration of Be in the inhalable fraction (122 ng m(-3), n = 30) was measured in the prebake pot room of a smelter using predominantly Jamaican alumina where also the highest individual air concentration of 270 ng m(-3) of Be was identified. The relative distribution of Be in the different aerosol fractions was fairly constant with the mean Be amount for the two sampling campaigns between 44-49% in the thoracic fraction expressed as % of the inhalable amount. Linear regression analysis shows a high correlation between water soluble Be, Al, F and Na describing an average measured chemical bulk composition of the water soluble thoracic fraction as Na(5.7)Al(3.1)F(18). Be is likely to be present as traces in this particulate matter by replacing Al atoms in the condensed fluorides and/or as a major element in a nanoparticle sized fluoride. Thus, the major amount of Be present in the work room atmosphere of Al smelter pot rooms will predominantly be present in combination with substantial amounts of water soluble Al, F and Na.  相似文献   
25.
Methods for household waste composition studies   总被引:1,自引:0,他引:1  
The question is how to conduct household waste composition studies. The review is divided into three parts: overview of known methods, sampling theory, and the waste components. Twenty methods are listed and commented on. There is no adopted, working international standard. In accordance with Pierre Gy's Theory of Sampling, the seven types of sampling errors, when collecting and splitting solid samples, are described and commented on in relation to sampling of household solid waste. It is concluded that the most crucial choices in household waste composition studies are: to divide the investigation into relevant number and types of strata; to decide the required sample size and number of samples; to choose the sampling location, i.e., sampling at household level or sampling from loads of waste collection vehicles; and to choose the type and number of waste component categories to be investigated. Various classifications of household waste components used in composition studies are listed and discussed. Difficulties and weaknesses of the reviewed methods are discussed and concluded in suggested questions for further research.  相似文献   
26.
Currently, the blast furnace (BF) to basic oxygen furnace (BOF) is the dominant steel production route in the steel industry. The direct CO2 emission in this process system exceeds 1 t of CO2/t of crude steel produced. Different ferrous burden materials, for instance iron ore and scrap, can be used in various proportions in this steelmaking route. This paper analyses how energy use, conversion costs, and CO2 emissions can be influenced by the use of different ferrous burden materials when producing crude steel. An optimisation mixed integer linear programming (MILP) model has been applied for analysis. By the use of the optimisation model, it is possible to highlight some issues of special importance, such as best practices to increase production at low conversion cost, or best practices to increase production at low CO2 emission. It is found out that more benefits will be gained when using the system-oriented analysis to the steelmaking process. Furthermore, a comprehensive view of the trade-offs between the objectives of Cost and CO2 can provide useful information for decision makers to generate strategies under the future emission trading.  相似文献   
27.
Accelerated pavement wear is one of the major environmental disadvantages of studded tyres in northern regions and results in increased levels of PM10. Measurements of PM10 in a road simulator hall have been used to study the influence of pavement properties, tyre type and vehicle speed on pavement wear. The test set-up included three different pavements (one granite and two quartzite with different aggregate sizes), three different tyre types (studded, non-studded, and summer tyres) and different speeds (30–70 km h?1). The results show that the granite pavement was more prone to PM10 production compared to the quartzite pavements. Studded winter tyres yield tens of times higher PM10 concentrations compared to non-studded winter tyres. Wear from summer tyres was negligible in comparison. It was also shown that wear is strongly dependent on speed; every 10 km h?1 increase yielded an increase of the PM10 concentration of 680 μg m?3 in one of the simulator experiments.  相似文献   
28.
P. Dahl  G. Lindstrm  K. Wiberg  C. Rappe 《Chemosphere》1995,30(12):2297-2306
The absorption of polychlorinated biphenyls, dibenzo-p-dioxins and dibenzofurans was studied in four breast-fed infants. The absorption was measured by comparing the estimated total intake and the excretion in faeces, during 48 hours, at three different time points; 1, 2 and 3 months post parta. The levels of the analysed compounds in the human milk are typical for Sweden, i.e 20 ppt toxic equivalents for the dibenzo-p-dioxins and dibenzofurans and for the polychlorinated biphenyls 16 ppt toxic equivalents. For most of the congeners the absorption is found to be over 95%. Higher excretion is noticed for heptachlorinated and octachlorinated dioxins.  相似文献   
29.
A denuder/filter system constructed for solvent-free personal exposure measurements was evaluated for separation of vapour and particulate 4,4'-methylenediphenyl diisocyanate (4,4'-MDI) generated from heated PUR-foam. The two different phases were collected in the denuder and on the filter, respectively, by chemosorption on a polydimethylsiloxane (SE-30)-dibutylamine (DBA) stationary phase. Both repeatability and the total mass concentration of 4,4'-MDI were similar to that obtained from the reference method, in this case an impinger/filter system. The penetration of particles through the denuder at 300 ml min(-1) was nearly 100% in the particle size range 25 to 700 nm, which fits well with the Gormley-Kennedy equation. Denuder/filter sampling of the 4,4'-MDI aerosol at 500 ml min(-1) yielded a phase distribution that was in accordance with the results from the reference method. The method limit of detection was 6 ng m(-3) and 4 ng m(-3) for the denuder and filter, respectively, when using an air sampling flow rate of 300 ml min(-1) and a sampling period of 15 min. This is well below the Swedish occupational exposure limit (OEL) of 50 and 100 microg m(-3) for an 8-hour working day and a 5-min period, respectively.  相似文献   
30.
Large size often confers a fitness advantage to female insects because fecundity increases with body size. However, the fitness benefits of large size for male insects are less clear. We investigated the mating behavior of the mayfly Baetis bicaudatus to determine whether the probability of male mating success increased with body size. Males formed mating aggregations (swarms) ranging from a few to hundreds of individuals, 1-4 m above the ground for about 1.5-2 h in the early morning. Females that flew near swarms were grabbed by males, pairs dropped to the vegetation where they mated and then flew off individually. Some marked males returned to swarms 1, 2 or 3 days after marking. Larger males swarmed near spruce trees at the edges of meadows, but the probability of copulating was not a function of male body size (no large male advantage). Furthermore, the potential fitness advantage of mating with larger, more fecund females was not greater for large males (no size-assortative mating). However, the sizes of copulating males were significantly less variable than those of non-mating males collected at random in swarms. Intermediate male size may be optimal during mating because of trade-offs between flight agility and longevity or competitive ability. Results of this study are consistent with the hypotheses that there is stabilizing selection on adult male body size during mating, and that male body size in this species may be influenced more by selection pressures acting on larvae than on adults.  相似文献   
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