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521.
We reviewed the use of captive European starlings (Sturnus vulgaris) in scientific research published between 2000 and 2004. We estimated the numbers of birds used and documented their origin and the range of husbandry regimes employed with the aim of comparing current practice with the new European guidelines for husbandry of laboratory animals. Over the five-year period, 106 primary articles report the use of an estimated total of 2490 captive starlings. The majority of birds were caught from the wild either as adults or fledglings, and only 3% were hand-reared from chicks. There was considerable variation in husbandry. In the majority of cases, standards fell below those currently recommended as best practice in the UK and cited in new European guidelines. The median volume of home cages employed was 0.42 m3 (0.13-5.1 m3, interquartile range), whereas current recommendations suggest a minimum of 1.0 m3 for a singly-housed bird. The median volume of space allowed per bird was 0.13 m3/bird (0.08-1.05 m3/bird, Q1-Q3), whereas current recommendations suggest a minimum of 0.33 m3/bird. Only 27% of the articles mentioned providing any form of environmental enrichment for birds in their home cages. We recommend that more research be conducted into the welfare of starlings to inform legislation and guidelines, and thus maximize the welfare of captive animals. 相似文献
522.
Carbon and Electron Flow in Mud and Sandflat Intertidal Sediments at Delaware Inlet, Nelson, New Zealand 总被引:4,自引:22,他引:4 下载免费PDF全文
Douglas O. Mountfort Rodney A. Asher Edward L. Mays James M. Tiedje 《Applied microbiology》1980,39(4):686-694
An investigation of carbon and electron flow in mud and sandflat intertidal sediments showed that the terminal electron acceptor was principally sulfate and that the carbon flow was mainly to CO2. Studies with thin layers of sediment exposed to H2 showed that methane production accounted for virtually none of the H2 utilized, whereas sulfate reduction accounted for a major proportion of the gas uptake. At all sampling sites except one (site B7), rates of methanogenesis were low but sulfate concentrations in the interstitial water were high (>18 mM). At site B7, the sulfate concentrations declined with depth from 32 mM at 2 cm to <1 mM at 10 cm or below, and active methanogenesis occurred in the low-sulfate zone. Sulfate-reducing activity at this site initially decreased and then increased with depth so that elevated rates occurred in both the active and nonactive methanogenic zones. The respiratory index (RI) [RI = 14CO2/(14CO2 + 14CH4)] for [2-14C]acetate catabolism at site B7 ranged from 0.98 to 0.2 in the depth range of 2 to 14 cm. Addition of sulfate to sediment from the low-sulfate zone resulted in an increase in RI and a decrease in methanogenesis. At all other sites examined, RI ranged from 0.97 to 0.99 and was constant with depth. The results suggested that although methanogenesis was inhibited by sulfate (presumably through the activity of sulfate-reducing bacteria), it was not always limited by sulfate reduction. 相似文献
523.
Role of Sulfate Reduction Versus Methanogenesis in Terminal Carbon Flow in Polluted Intertidal Sediment of Waimea Inlet, Nelson, New Zealand 下载免费PDF全文
An investigation of the terminal anaerobic processes occurring in polluted intertidal sediments indicated that terminal carbon flow was mainly mediated by sulfate-reducing organisms in sediments with high sulfate concentrations (>10 mM in the interstitial water) exposed to low loadings of nutrient (equivalent to <102 kg of N · day−1) and biochemical oxygen demand (<0.7 × 103 kg · day−1) in effluents from different pollution sources. However, in sediments exposed to high loadings of nutrient (>102 kg of N · day−1) and biochemical oxygen demand (>0.7 × 103 kg · day−1), methanogenesis was the major process in the mediation of terminal carbon flow, and sulfate concentrations were low (≤2 mM). The respiratory index [14CO2/(14CO2 + 14CH4)] for [2-14C]acetate catabolism, a measure of terminal carbon flow, was ≥0.96 for sediment with high sulfate, but in sediments with sulfate as little as 10 μM in the interstitial water, respiratory index values of ≤0.22 were obtained. In the latter sediment, methane production rates as high as 3 μmol · g−1 (dry weight) · h−1 were obtained, and there was a potential for active sulfate reduction. 相似文献
524.
Alexander Sullivan Priyank K. Purohit Nowlan H. Freese Asher Pasha Eddi Esteban Jamie Waese Alison Wu Michelle Chen Chih Y. Chin Richard Song Sneha R. Watharkar Agnes P. Chan Vivek Krishnakumar Matthew W. Vaughn Chris Town Ann E. Loraine Nicholas J. Provart 《The Plant journal : for cell and molecular biology》2019,100(3):641-654
525.
Effect of maternal diabetes on the embryo,fetus, and children: Congenital anomalies,genetic and epigenetic changes and developmental outcomes 下载免费PDF全文
526.
The salinity of industrial wastewater evaporation ponds was artificially increased from 3-7% to 12-16% (w/v), in an attempt to reduce the activity of sulfate-reducing bacteria (SRB) and subsequent emission of H2S. To investigate the changes in bacterial diversity in general, and SRB in particular, following this salination, two sets of universal primers targeting the 16S rRNA gene and the functional apsA [adenosine-5'-phosphosulfate (APS) reductase alpha-subunit] gene of SRB were used. Phylogenetic analysis indicated that Proteobacteria was the most dominant phylum both before and after salination (with 52% and 68%, respectively), whereas Firmicutes was the second most dominant phylum before (39%) and after (19%) salination. Sequences belonging to Bacteroidetes, Spirochaetes and Actinobacteria were also found. Several groups of SRB from Proteobacteria and Firmicutes were also found to inhabit this saline environment. Comparison of bacterial diversity before and after salination of the ponds revealed both a shift in community composition and an increase in microbial diversity following salination. The share of SRB in the 16S rRNA gene was reduced following salination, consistent with the reduction of H2S emissions. However, the community composition, as shown by apsA gene analysis, was not markedly affected. 相似文献
527.
528.
Patterns of nucleotide polymorphism distinguish temperate and tropical wild isolates of Caenorhabditis briggsae 下载免费PDF全文
Caenorhabditis briggsae provides a natural comparison species for the model nematode C. elegans, given their similar morphology, life history, and hermaphroditic mode of reproduction. Despite C. briggsae boasting a published genome sequence and establishing Caenorhabditis as a model genus for genetics and development, little is known about genetic variation across the geographic range of this species. In this study, we greatly expand the collection of natural isolates and characterize patterns of nucleotide variation for six loci in 63 strains from three continents. The pattern of polymorphisms reveals differentiation between C. briggsae strains found in temperate localities in the northern hemisphere from those sampled near the Tropic of Cancer, with diversity within the tropical region comparable to what is found for C. elegans in Europe. As in C. elegans, linkage disequilibrium is pervasive, although recombination is evident among some variant sites, indicating that outcrossing has occurred at a low rate in the history of the sample. In contrast to C. elegans, temperate regions harbor extremely little variation, perhaps reflecting colonization and recent expansion of C. briggsae into northern latitudes. We discuss these findings in relation to their implications for selection, demographic history, and the persistence of self-fertilization. 相似文献
529.
High nucleotide polymorphism and rapid decay of linkage disequilibrium in wild populations of Caenorhabditis remanei 下载免费PDF全文
The common ancestor of the self-fertilizing nematodes Caenorhabditis elegans and C. briggsae must have reproduced by obligate outcrossing, like most species in this genus. However, we have only a limited understanding about how genetic variation is patterned in such male-female (gonochoristic) Caenorhabditis species. Here, we report results from surveying nucleotide variation of six nuclear loci in a broad geographic sample of wild isolates of the gonochoristic C. remanei. We find high levels of diversity in this species, with silent-site diversity averaging 4.7%, implying an effective population size close to 1 million. Additionally, the pattern of polymorphisms reveals little evidence for population structure or deviation from neutral expectations, suggesting that the sampled C. remanei populations approximate panmixis and demographic equilibrium. Combined with the observation that linkage disequilibrium between pairs of polymorphic sites decays rapidly with distance, this suggests that C. remanei will provide an excellent system for identifying the genetic targets of natural selection from deviant patterns of polymorphism and linkage disequilibrium. The patterns revealed in this obligately outcrossing species may provide a useful model of the evolutionary circumstances in C. elegans' gonochoristic progenitor. This will be especially important if self-fertilization evolved recently in C. elegans history, because most of the evolutionary time separating C. elegans from its known relatives would have occurred in a state of obligate outcrossing. 相似文献
530.
W. Powell E. M. Borrino M. J. Allison D. W. Griffiths M. J. C. Asher J. M. Dunwell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,72(5):619-626
Summary From an F1 hybrid between the two barley (Hordeum vulgare L.) cultivars Golden Promise and Mazurka a series of doubled haploid (DH) lines were generated both from microspores by anther culture and from immature zygotic embryos after hybridization withH. bulbosum. The DH lines from both sources were used to monitor the segregation of the five major genes, rachilla hair length, DDT susceptibility, height, C hordein polymorphism and mildew resistance. Whereas the microspore-derived samples showed significant departures from the expected 11 ratio for three of the five genes, theH. bulbosum lines showed deviation for only one gene. Analysis of linkage data also showed differences between the two series of DH lines. Cytogenetic analysis revealed a mean chiasma frequency in theH. bulbosum lines which was very similar to the F1 hybrid. In contrast, four of the ten microspore derived lines examined showed a reduced chiasma frequency. One showed evidence of translocation heterozygosity. 相似文献