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881.
Environment Systems and Decisions - Early warning systems for weather events are becoming widespread as technological capacities develop. For warnings to be effective, they must allow enough lead... 相似文献
882.
McLaughlin JP Vintró LL Smith KJ Mitchell PJ Zunić ZS 《Journal of environmental radioactivity》2003,64(2-3):155-165
Following the detection of 236U in depleted uranium (DU) ammunition used during the Balkans conflict in the 1990s, concern has been expressed about the possibility that other nuclides from the nuclear fuel cycle and, in particular, transuranium nuclides, might be present in this type of ammunition. In this paper, we report the results of uranium and plutonium analyses carried out on a depleted uranium penetrator recovered from a target site in southern Serbia. Our data show the depleted nature of the uranium and confirm the presence of trace amounts of plutonium in the penetrator. The activity concentration of (239+240)PU, at 45.4+/-0.7 Bq kg(-1), is the highest reported to date for any penetrator recovered from the Balkans. This concentration, however, is comparable to that expected to be present naturally in uranium ores and, from a radiological perspective, would only give rise to a very small increase in dose to exposed persons compared to that from the DU itself. 相似文献
883.
884.
Íñigo Oleagordia Montaña Joaquín Navarro Hevia Almudena Gómez-Ramos 《Journal of Land Use Science》2016,11(3):310-330
The environment provides many necessary services for a plethora of human activities related to that are being acknowledged as our ecosystems degrade; therefore, ecosystem-based solutions are becoming increasingly more important. Hydrologic restorations (HRs) apply this type of ecosystem approach; there are multiple examples around the Mediterranean area executed since the beginning of the twentieth century. One good example of these restoration-type solutions can be seen in the badlands of Saldaña (Palencia, Spain). This case has been particularly successful in stopping gully erosion from badlands. Despite its importance for the well-being of the inhabitants of Saldaña and surroundings, the economic effects of these services which were put into place by this HR have never been assessed. In the present study, four different and compatible ecosystem restored services have been valued in monetary terms. For their aggregation, an innovative approach has been taken using the analytic hierarchy process methodology, so the weight of each ecosystem service (ES) can be determined. The economic flow of these ESs has been calculated in terms of annual income and updated values, from which natural capital increase in the population of Saldaña can be assessed. After analysing the results, it can be concluded that the village has earned more than seven million euros, which, in turn, generates important benefits to its inhabitants. 相似文献
885.
886.
László?Zsolt?GaramszegiEmail author Anders?Pape?M?ller 《Behavioral ecology and sociobiology》2012,66(1):107-119
Hamilton and Zuk (Science 218:384–387, 1982) supported their influential hypothesis of parasite-mediated sexual selection based on a positive interspecific correlation
between the prevalence of blood parasites and the expression of male displays in birds. However, subsequent studies provided
mixed support for this relationship after considering several confounding factors. Here, we revisit this fundamental prediction
by refining the analyses through implementation of recent methodological advancements. First, we distinguish between prevalence
data obtained through microscopic and molecular tools, as PCR-based detection methods may be more sensitive for detecting
infection. Second, we use quantitative estimates of both acoustic and visual signals of males, in which color measurements
adopt the perspective of avian vision. Third, applying modern phylogenetic comparative approaches, we correct for phylogenetic
inertia as well as heterogeneity in sampling effort. Fourth, we distinguish between prevalence transition states, as we compare
species with and without evidence of infection and also monitor changes in parasite prevalence only in species in which blood
parasites are detected. We show that given the considerable variation among populations, the repeatability of prevalence at
the within-species level is modest. We failed to detect a strong interspecific relationship between the prevalence of blood
parasites and sexual traits. However, we found that an evolutionary increase from zero to non-zero prevalence is likely to
be accompanied by an increase in trait expression in males, but further increase from non-zero prevalence to a higher level
of infection tends to be associated with a reduced degree of trait elaboration. Our results provide some support to the Hamilton
and Zuk hypothesis, but the relationship between blood parasites and male displays varies among traits depending on degree
of infection. 相似文献
887.
M.?KoskiEmail author L.?Yebra J.?Dutz S.?H.?J?nasd?ttir C.?Vidoudez H.?H.?Jakobsen G.?Pohnert J.?C.?Nejstgaard 《Marine Biology》2012,159(3):643-660
We studied the effect of a developing Skeletonema marinoi/Phaeocystis spp. bloom on Calanus finmarchicus hatching success, early naupliar survival and metabolism. Our focus was (1) on the development of reproductive rates during
a bloom initiation, peak and decline in relation to the production of potentially toxic algal metabolites and (2) on the proportional
importance of female nutrition versus naupliar food environment for the production of viable nauplii. Despite polyunsaturated
aldehyde (PUA) production by both S. marinoi and Phaeocystis sp., we did not observe any harmful effects on hatching success or naupliar survival and condition in any stages of the short-term
(<1 week) algal bloom. Hatching success appeared to be controlled by egg lipid composition, while the beneficial effect of
a high food concentration was reflected in naupliar RNA:DNA ratio, protein content and total production of viable nauplii.
The egg lipids reflected seston lipids, indicating that the egg fatty acid composition was not modified by the females. Our
results suggest that unselective feeding and/or retention of specific lipids can induce qualitative food limitation, although
recruitment during the S. marinoi/Phaeocystis sp. bloom was high. 相似文献
888.
József Vuts Till Tolasch Lorenzo Furlan éva Bálintné Csonka Tamás Felf?ldi Károly Márialigeti Teodora B. Toshova Mitko Subchev Amália Xavier Miklós Tóth 《Chemoecology》2012,22(1):23-28
The presence of geranyl octanoate, previously found in pheromone gland extracts of Agriotes lineatus females, was also demonstrated in gland extracts of A. proximus females. Similar to A. lineatus, geranyl butanoate was present only in trace amounts in A. proximus female gland extracts. In air entrainment samples of female A. lineatus and A. proximus beetles, the relative ratio of geranyl butanoate and geranyl octanoate was higher than that in gland extracts. In addition,
comparison of a segment of the mitochondrial cytochrome c oxidase subunit I gene of feral specimens of A. lineatus and A. proximus showed >99% similarity. Both pheromone profile and nucleotide sequence analysis delineate close relationship between the
investigated taxa and postulate taxonomic revision. Further studies on sympatric populations of A. lineatus and A. proximus are underway to investigate and better understand possible processes of species diversification. 相似文献
889.
890.
M. Dolores G. López-de-Hierro Gregorio Moreno-Rueda 《Behavioral ecology and sociobiology》2010,64(3):317-324
Brood parasitism could be a selective pressure on each female to have a type of egg that permits recognition. House sparrows
(Passer domesticus) undergo conspecific brood parasitism and can recognise parasitic eggs. In this study, we analyse the effect of relative
size in experimental parasitic eggs compared to the host eggs. We modified egg colour and the spot pattern to determine the
influence of these characteristics on egg rejection. Furthermore, we examine whether egg rejection increases with “stimulus
summation”. Our results show that egg rejection is not affected by relative egg size. However, changes in the spot pattern
proved to exert the highest influence on egg rejection (32.4% of trials), significantly higher than when only egg colour is
changed (3.8%). Therefore, our results suggest that parasitism may be a pressure favouring the maintenance of spotted eggs
in house sparrow. 相似文献