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31.
The aim of the study was to evaluate the possibility of supplementation with inorganic forms of selenium (Na2SeO4 and Na2SeO3) in concentrations of 0, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 and 1.5 mM of three medicinal mushroom species: Agrocybe aegerita, Hericium erinaceus and Ganoderma lucidum. Tested mushroom species grew in Se additions of 0–0.6 mM (A. aegerita and H. erinaceus), while growth of G. lucidum bodies was observed for 0–0.8 mM. For the latter mushroom species, the total Se content was the highest. Content of Seorg was diverse; for control bodies it was the highest for G. lucidum (only organic forms were present), lower for A. aegerita (84% organic forms) and the lowest for H. erinaceus (56% organic forms). Accumulation of Se(IV) was generally significantly higher than Se(VI) for all tested mushroom species. There was no significant decrease of A. aegerita or G. lucidum biomass with the exception of G. lucidum bodies growing under 0.8 mM of Se species addition (15.51 ± 6.53 g). Biomass of H. erinaceus bodies was the highest under 0.2 (197.04 ± 8.73 g), control (191.80 ± 6.06 g) and 0.1 mM (185.04 ± 8.73 g) of both inorganic salts. The addition to the medium of Se salts brought about macroscopic changes in the fruiting bodies of the examined mushrooms. Concentrations exceeding 0.4 mM caused diminution of carpophores or even their total absence. In addition, colour changes of fruiting bodies were also recorded. At Se concentrations of 0.4 and 0.6 mM, A. aegerita fruiting bodies were distinctly lighter and those of H. erinaceus changed colour from purely white to white-pink.  相似文献   
32.
A laboratory experiment was performed to examine the remobilization of indicator polychlorinated biphenyls (iPCBs) from sediments and its results were applied to the real-world data for explaining the transport of PCBs in river. Seven PCB concentrations were determined in three series of model water–sediment systems (3 g of river sediment, three different volumes of distilled water (0.5, 0.25, and 0.15 ml), and 5 mg of biocide) after 11 days of incubation. Solid-phase extraction was used for separation of analytes from the aqueous phase and solvent extraction for isolation of analytes from the sediments, respectively. The extracts were analyzed for individual iPCB congeners using gas chromatography–mass spectrometry method. For each series of the experiment, the concentrations of PCBs in aqueous phase were similar. The average sediment/water partition coefficient value was 104?l/kg. The solubility of individual PCB congeners in water did not influence the desorption of PCBs from the sediment. Although the dominant form of PCBs in a water–sediment system occurs as suspended and colloidal fractions, these compounds are transported mostly in a dissolved form. Suspended and colloidal matter is a major sink for PCBs in low-energy aquatic environments. In contrast, the dissolved PCBs are readily transported in running waters. The mobilization of PCBs from sediments to aqueous phase, with respect to their solubility in water, seems to be limited, thus reducing the risk of secondary pollution.  相似文献   
33.
Temporal and spatial patterns of micropollutants in urban receiving waters   总被引:1,自引:0,他引:1  
Based on a monitoring program over the course of a year, we characterize the temporal and spatial distribution of selected micropollutants in an urban watershed within the city of Leipzig, Germany. Micropollutants revealed a ubiquitous presence in untreated and treated wastewater, surface water and groundwater. The loads of 4-nonylphenol in the effluents of the municipal wastewater treatment plant followed a seasonal trend, whereas the loads of all other micropollutants were highly variable and not correlated to seasons. In the surface water, load seasonality of caffeine, galaxolide and tonalide resulted from a rapid removal with increased water temperature. The loads of 4-nonylphenol and of caffeine in the colder months increased when rainfall occurred. In the groundwater, complex spatial and temporal patterns were apparent and were related to varying input, retardation and removal processes. As a consequence, an assessment of micropollutants in urban waters should consider different micropollutants' temporal and spatial variability.  相似文献   
34.
Using the reproductive capacity of fish appears to be a suitable approach for risk assessment in the aquatic environment since fish are a typical representative thereof and in addition they are of considerable societal value. Generally the early embryonic stages are considered to be one of the most sensitive parts of a fish's life cycle. A method has been developed to use the state of health of live, naturally spawned fish embryos from plankton samples for biological effects monitoring. During the years 1985–1987 in the southern North Sea and in 1991–1992 in the whole of the North Sea fish eggs were sampled from surface waters and examined for developmental abnormalities. Elevated embryo malformation rates were detected in the plume of the major rivers Elbe and Rhine as well as along the eastern coast of England. Occurring malformations are thought to be pollution-related and may be used to define areas of environmental deterioration. The method is discussed in view of its suitability for biological effects monitoring using malformations in fish embryos as biomarkers.  相似文献   
35.
Sorption dynamics of organic and inorganic phosphorus compounds in soil   总被引:1,自引:0,他引:1  
Phosphorus retention in soils is influenced by the form of P added. The potential impact of one P compound on the sorption of other P compounds in soils has not been widely reported. Sorption isotherms were utilized to quantify P retention by benchmark soils from Indiana, Missouri, and North Carolina when P was added as inorganic P (Pi) or organic P (beta-D-glucose-6-phosphate, G6P; adenosine 5'-triphosphate, ATP; and myoinositol hexaphosphate, IP6) and to determine whether soil P sorption by these organic P compounds and Pi was competitive. Isotherm supernatants were analyzed for pH and total P using standard protocols, while Pi and organic P compounds were assayed using ion chromatography. Under the controlled conditions of this study, the affinity of all soils for P sources followed the order IP6 > G6P > ATP > Pi. Each organic P source had a different potential to desorb Pi from soils, and the order of greatest to least Pi desorption was G6P > ATP > IP6. Glucose-6-phosphate and ATP competed more directly with Pi for sorption sites than IP6 at greater rates of P addition, but at the lesser rates of P addition, IP6 actually desorbed more Pi. Inositol hexaphosphate was strongly sorbed by all three soils and was relatively unaffected by the presence of other P sources. Decreased total P sorption due to desorption of Pi can be caused by relatively small additions of organic P, which may help explain vertical P movement in manured soils. Sorption isotherms performed using Pi alone did not accurately predict total P sorption in soils.  相似文献   
36.
Genetic counseling for prenatal diagnosis of autosomal trisomy is complex because of the uncertainty of outcome, which is important for management decisions. Compilation of cases of prenatally diagnosed autosomal trisomies in amniocytes has been done previously in an attempt to elucidate the clinical phenotype of these pregnancies. It has been greater than a decade since these studies were completed. To update this work, we reviewed cases reported in the literature since that time. These cases are correlated with the prior reports to increase knowledge about outcomes and to hopefully improve the data available for genetic counseling. The risk of abnormal outcome can be summarized as: very high risk (>60%) for 47,+2/46; 47,+9/46; 47,+16/46; 47,+20/46; and 47,+22/46; high risk (40–59%) for 47,+5/46; 47,+14/46; and 47,+15/46; moderately high risk (20–39%) for 47,+7/46 47,+12/46; and 47,+17/46; moderate risk (up to 19%) for 47,+6/46 and 47,+8/46, and none were low risk. 47,+6/46 was originally indeterminate, 47,+7/46 was originally moderate risk, 47,+9/46 was originally high risk, and 47,+17/46 was originally low risk. © 2015 John Wiley & Sons, Ltd.  相似文献   
37.
Asplenia associated with situs ambiguus, symmetric liver, bilateral trilobulated lungs, and a complex heart defect was diagnosed on autopsy in a 14-day-old infant. Furthermore, examination of the brain displayed agenesis of the corpus callosum (ACC) with pachygyria and hydrocephalus. The characteristic association of asplenia with visceroatrial heterotaxia is traditionally named after the Swedish pediatrician, Ivemark. Although exceptional, association of Ivemark syndrome with callosal agenesis has been reported recently. The concept of ‘developmental fields’ describes morphogenetically reactive units of the embryo determining and controlling the development of complex structures in a hierarchical manner. Lateralization defects such as situs inversus, asplenia or polysplenia due to defective left–right axis development, as well as decussation defects such as ACC, are considered as defects of the primary developmental field. Therefore, additional callosal agenesis in Ivemark syndrome may be a coherent and synchronic defect in the primary developmental field rather than a causally independent malformation. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
38.
It was expected that there would be informal rules of several kinds for working relationships. In the first study subjects rated 33 common rules and a number of relationship-specific rules for three work roles. It was found that certain rules were strongly endorsed for work-mates, superiors and subordinates. These provide a maintenance function by regulating general and relationship-specific sources of conflict. Rules about cooperation, help and fairness applied strongly to work-mates, rules about consideration and skilful use of power to supervisors, rules about using initiative and accepting orders and criticism to subordinates. Rules about reward were also obtained and these tended to be task-focused rather than intimacy sustaining. In the second study one hundred and twenty-four subjects rated the degree of dissatisfaction which they would feel for 11 types of rule violation by each of four work colleagues varying in degree of intimacy. Some level of dissatisfaction was expressed for each rule violation particularly maintenance rules, and the degree of expressed dissatisfaction increased with increased closeness to the work colleague. Study I was replicated in three other countries — Italy, Hong Kong and Japan, and cross-cultural comparisons were made. While there was some cross-cultural consistency for certain maintenance rules, there were cultural differences both in the type of rules endorsed and the strength of endorsement. Japanese relationships in particular were most dissimilar to other countries, characterized by greater homogeneity of overall rule structure within the four work roles, and by lower levels of intimacy and emotional expressiveness towards the other person in each relationship.  相似文献   
39.
Fly ash extracts were fed to male hamster (single dose), male rat (single dose and multiple dose), pregnant and lactating female rat (multiple dose). The retention of four isomers, 2,3,7,8-TCDD, 2,3,7,8-TCDF, 1,2,3,7,8-PnCDD and 2,3,4,7,8-PnCDF, was studied in the liver of the adults, foetuses and liver of the sucklings.

Liver retention was structure dependent and different for both species. Transportation of the isomers via the mother milk was 50–100 times more effective than via the placenta.

After a single intravenous dose of fly ash extract to male rats the elimination of these four isomers was studied in the liver, during a period of 10 days. Elimination rates for 2,3,7,8-TCDD, 1,2,3,7,8-PnCDD and 2,3,4,7,8-PnCDF were in the same range. Pharmacokinetic calculations were done on both tetra congeners, to obtain information about the validity of the published Ke values in the multiple dose experiments with male rats.

For 2,3,7,8-TCDF the Ke value was applicable, but for 2,3,7,8-TCDD the validity of the Ke could not be determined.  相似文献   

40.
Alkan Olsson J  Berg K 《Ambio》2005,34(7):507-512
The objective of this study was to increase the knowledge of local stakeholders' acceptance of model-generated data when used as a communication tool in water quality management. The R?nne? catchment in the southwest of Sweden was chosen as the study area. The results indicate the model-generated data served as a uniting factor. Simultaneously, the stakeholders were concerned with presented data, the main problems being sources of pollution, which were not accounted for, lack of trustworthiness when measuring pollution, and the uncertainty of the impact of natural variation and delayed effects. Four clusters of factors were identified as influencing stakeholders' acceptance of the model-generated data: confidence in its practical applications, confidence in the people involved in or providing material for the dialog (such as experts, decision-makers, and media), the social characteristics of the participants (such as age and profession), and the way of communicating the data (such as tone of communication, group composition, duration, and geographical scope of the dialog). The perception of the fairness of the practical application of given model-generated data was also an important factor for acceptance.  相似文献   
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