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721.
It is unclear why some firms suffer greater negative consequences than others following a product recall. To shed light on this question, we extend attribution theory to the firm level to explore how consumers engage in an attributional process following product recalls that shapes their responses to firms. Integrating attribution theory and the demand side theoretical perspective, we assert that consumer judgments of responsibility toward manufacturers are shaped by causal data regarding the locus of causality (i.e., manufacturer or supplier) and controllability (i.e., prior knowledge or awareness) of a recalled product's potential for harm. We then examine the impact of product recall characteristics on judgments of responsibility and firm‐level outcomes using an experimental test involving responses from 320 subjects. Our findings suggest that judgments of responsibility are attributed to the manufacturing firm more when consumers are given causal information indicating that the firm is the source of, or is aware of, a product's defects. The results also indicate that judgments of responsibility can have costly firm‐level consequences in the form of reputational damage, diminished consumer purchase intentions, and increased legal damage recommendations. We discuss theoretical contributions, practical implications, and opportunities for further research.  相似文献   
722.
Congenital nephrosis of the Finnish type (CNF) is rare outside Finland, where the incidence may be as high as 1 in 2000 live births. Neonates with the disorder develop renal failure within the first months of life and without renal transplantation, the prognosis is extremely poor. This case report describes a woman's three pregnancies, two of which were affected with CNF.  相似文献   
723.
The fish at sites located throughout the large, seasonally closed Wilson Inlet, on the southern coast of Western Australia, were sampled bimonthly between September 1987 and April 1989. Seine nets were used to sample nearshore shallow waters, while gill nets were employed in slightly more offshore and deeper waters. Twenty species were recorded in the shallows, of which the three species of atherinid and the three species of goby comprised >97% of the total catch. In terms of number of individuals, the 27 species recorded in gill nets in the deeper waters were dominated by Cnidoglanis macrocephalus and Platycephalus speculator, and to a lesser extent Engraulis australis, Aldrichetta forsteri, Sillaginodes punctata and Arripis georgianus. Fifty-five percent of the species recorded in the nearshore shallow waters and 18% of those in offshore deeper waters spawn within Wilson Inlet; these species contributed 98.5 and 63.0%, respectively, to the total catches in those waters. Classification and ordination showed that the composition of the fauna in the shallows was similar at all sites throughout the large basin and did not change conspicuously with season. However, the composition of catches taken in offshore waters differed between the lower part of the basin and the middle and upper regions of the basin, which in turn differed from those in the saline reaches of a tributary river. The four diagnostic species of the lower estuary were all marine species, while the three diagnostic species in the river included a marine species (Mugil cephalus) that often penetrates far upstream in other systems, and a species which was confined to the rivers (Acanthopagrus butcheri). The composition of the fish fauna in the offshore waters of the lower estuary between the middle of spring and middle of autumn was different in 1987/1988 (when the estuary mouth was open for only the first two months of that period) from that in 1988/1989 (when the mouth was open for the whole of that period). This difference is related to the greater number of marine species that were retained in the first of these years, when the estuary was open to the ocean for only a short period. The greater retention of marine species in 1987/1988 than in 1988/1989 probably reflects a far lower level of freshwater flusing and/or a less marked decline in salinity.  相似文献   
724.
Following a brood size manipulation experiment on the common swift (Apus apus) in which different levels of parental effort were created, brood reduction occurred in all five nests manipulated to four chicks and in two of the five manipulated to three young. This provided an opportunity for looking in detail at the parental investment decisions concerning allocation strategies between parent and young during the process of brood reduction. The data recorded here were analysed on a visit-by-visit basis regarding changes in parental and chick body masses, the mass of prey delivered and the estimated mass of parental self-feeding. The results show that food delivery rates did not increase in proportion to the number of chicks in the broods. This reduction in delivery rates per chick resulted in lower chick masses and ultimately in the death of one or more chicks in the larger broods. The resulting low parental body masses for adult birds feeding larger broods suggested that these parents could not have raised all their young without risking their own survival. There was a tendency for parents from nests that experienced brood reduction to feed themselves instead of allocating most of the food gathered to the young. After brood reduction, parents regained lost body mass and their young fledged at masses only slightly lower than normal. The differential allocation decisions regarding parental self-feeding which resulted in brood reduction were largely responsible for keeping the parents in good enough condition to care for the surviving nestlings. Therefore, this study clearly demonstrates that brood reduction can operate through the differential allocation of food between parent and young in a way that can have adaptive consequences for the survival of parents and their young. Correspondence to: T.L.F. Martins  相似文献   
725.
Previous work has shown that under elevated predation risk, male guppies (Poecilia reticulata) switch from courtship to less conspicuous coercive mating attempts. This behavioural transition is traditionally interpreted as a 'risk-sensitive' response that makes males less conspicuous to predators. However, predation risk leads to behavioural changes (such as schooling and predator inspection) in females that may result in coercive mating attempts being more profitable in high-risk situations. Here, we tested the hypothesis that the switch to coercive mating by male guppies in high-risk situations is mediated by adjustments in female behaviour, rather than directly by the predator. We used replicate models resembling a known guppy predator to simulate predation risk in wild-caught guppies from a high-predation population in Trinidad. Our results revealed that males performed proportionately more coercive mating attempts when presented with a female that had been exposed previously to a model predator compared to when males were paired with non-exposed females. Total mating activity (combined rates of courtship and forced mating attempts) did not differ significantly among the two treatment groups, indicating that overall mating activity is unaffected by predation risk. Importantly, when we subsequently presented both sexes concurrently with a predator model, total mating activity and the proportion of forced mating attempts remained unchanged in the high-risk treatment. Taken together, these results indicate that the transition from courtship to forced mating attempts under elevated predation risk is mediated by changes in female behaviour, which we suggest may favour the use of coercive mating under high predation risk.  相似文献   
726.
We examined the genetic relationship among putative parents, offspring, and helpers in 224 red-cock-aded woodpeckers (Picoides borealis) from the Sandhills of North Carolina. Comparison of DNA similarity with a pedigree constructed from 3,823 individually-marked birds observed from 1979 to 1992 provided verification of observed relatedness in the sampled population (R 2 = 0.87, df = 14, P < 0.001). In this population, breeding pairs may or may not have helpers, most of which are males that remain on their natal territory. Our sample included helpers assisting their parents, helpers assisting a related male and an unrelated female, and helpers assisting an unrelated pair. Band by band comparison and examination of similarity among DNA profiles indicated that all offspring from non-helped nests were sired by their putative parents (n = 28 families). Similarly, all but one offspring in helped nests were also sired by their putative parents (n = 16 families). In the exceptional case, the offspring evidently was sired by a male external to the group. Analysis of similarity values supported the conclusion that matings by helpers or extra-group males are rare or non-existent. Our results indicate that in this species advantages gained by individuals remaining on their natal territories as helpers do not generally include siring offspring. Correspondence to: S. Haig  相似文献   
727.
Seven cases of triploidy were encountered by the Prenatal Diagnosis Program at Dartmouth–Hitchcock Medical Center over an 8-year period through associated pregnancy complications. We describe the characteristic findings that facilitate prenatal diagnosis and management. Our experience includes fetuses with major central nervous system abnormalities (spina bifida aperta, holoprosencephaly) and anterior abdominal wall defects, which are detectable with routine prenatal diagnostic screening examinations (ultrasound and AFP). In addition, we stress the importance of recognizing obstetric complications and associated cystic placental changes, which are quite common among triploid conceptuses. Molar changes associated with triploidy have a more benign prognosis than that associated with diploid moles. Such molar changes may relate to the presence of a diploid paternal chromosome complement. The usefulness of cytofluorometric DNA determinations in helping to confirm a clinical suspicion of triploidy is emphasized. These cases are presented in an effort to facilitate prenatal recognition and management of this common cytogenetic condition and prevent unnecessary Caesarean section deliveries.  相似文献   
728.
1-Bromo-propane (1-BP) is a replacement for high-end chlorofluorocarbon (HCFC) solvents. Its reaction rate constant with the OH radical is, on a weight basis, significantly less than that of ethane. However, the overall smog formation chemistry of 1-BP appears to be very unusual compared with typical volatile organic compounds (VOCs) and relatively complex because of the presence of bromine. In smog chamber experiments, 1-BP initially shows a faster ozone build-up than what would be expected from ethane, but the secondary products containing bromine tend to destroy ozone such that 1-BP can have a net overall negative reactivity. Alternative sets of reactions are offered to explain this unusual behavior. Follow-up studies are suggested to resolve the chemistry. Using one set of bromine-related reactions in a photochemical grid model shows that 1-BP would be less reactive toward peak ozone formation than ethane with a trend toward even lower ozone impacts in the future.  相似文献   
729.
Two approaches were used to investigate the influence of dissolved oxygen (DO) and substrate availability on the formation and dynamics of "bioactive zones" in a water-saturated porous medium. A bioactive zone is defined as a region where a microbial community is sufficiently active to metabolize bioavailable substrates. In the first approach, microbial activity was characterized by monitoring the spatial and temporal variability of DO and aqueous substrate (salicylate and naphthalene) concentrations during miscible-displacement experiments. In the second approach, microbial activity was monitored using multiple fiber optics emplaced in the porous medium to detect luminescence produced by Pseudomonas putida RB1353, a bioluminescent reporter organism that produces light when salicylate (an intermediate of naphthalene degradation) is present. The results of both approaches show that the location and size of the bioactive zones were influenced by in situ DO and substrate availability. When DO was not a limiting factor (i.e., lower substrate input concentrations), the bioactive zone encompassed the entire column, with the majority of the microbial activity occurring between the inlet and midpoint. However, as the availability of DO became limiting for the higher substrate input experiments, the size of the bioactive zone shrank and was ultimately limited to the proximity of the column inlet.  相似文献   
730.
Pregnant Long Evans rats received 1.0 μg/kg of dioxin toxic equivalents (TEQ) by oral gavage on the 15th gestational day (GD 15), using a dosing mixture that contained two polychlorinated dioxins, four polychlorinated furans and three non-ortho polychlorinated biphenyls (PCBs). Rats were sacrificed on GD 16, GD 21 and postnatal day 4 (PND 4). The lipid content of fetus, pup, placenta and maternal liver, serum and adipose tissue were determined. Treated GD 16 and GD 21 fetuses had identical lipid content to the control group, yet the lipid content of treated pups on PND 4 was 32% higher than that of the control group. On the other hand, the lipid content of placenta, liver, and serum from the treated dams was 44–50%, 24%, and 38% lower than that of the control group, respectively. Thus, a low-dose mixture of dioxin-like compounds can cause changes in lipid content. The lipid content of offspring was not affected until they were exposed via lactation.  相似文献   
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