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421.
Sonia Chelinho Xavier Domene Paolo Campana Pilar Andrés Jörg Römbke José Paulo Sousa 《Journal of Soils and Sediments》2014,14(3):584-599
Purpose
The main objective of the present study was to evaluate the toxicity of two reference chemicals, Carbendazim and Phenmedipham, for the compostworm Eisenia andrei (effects of Carbendazim) and the potworm Enchytraeus crypticus (effects of Phenmedipham) in 12 Mediterranean soils with contrasting soil properties. The observed toxicity was also compared to that obtained for OECD standard soil, used as a control.Materials and methods
The soils were selected to be representative for the Mediterranean region and to cover a broad range of soil properties. The evaluated endpoints were avoidance behavior and reproduction. Soils were also assembled in two groups according to their pedological properties.Results and discussion
Toxicity benchmarks (AC50s) obtained for E. andrei avoidance behavior in carbendazim-contaminated soils were generally higher for sandy soils with low pH. The toxic effects on the reproduction of the compostworms were similar in the six tested soils, indicating a low influence of soil properties. The avoidance response of E. crypticus towards Phenmedipham was generally highly variable in all tested soils. Even though, a higher toxicity was observed for more acidic soils. The EC50s for reproduction of the latter species varied by a factor of 9 and Phenmedipham toxicity also tended to be increasing in soils with lower pH, except for the soils with extreme organic matter content (0.6 and 5.8%).Conclusions
A soil effect on chemical toxicity was clearly confirmed, highlighting the influence that test soils can have in site-specific ecological risk assessment. Despite some relationships between soil properties and toxicity were outlined, a clear and statistically significant prediction of chemical toxicity could not be established. The range of soil properties was probably narrow to give clearer and more consistent insights on their influence. For the four groups of tests, the toxicity observed for OECD soil was either similar, lower, or generally higher if compared with Mediterranean soils. Moreover, it did represent neither the organic matter content found in Mediterranean soils nor their textural classes. 相似文献422.
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Microbiologists have long been puzzled by the finding that the gut mucosa does not respond to the myriad varieties of bacteria that normally reside in the gut. As Xavier and Podolsky explain in their Perspective, this may be because bacteria that are indigenous to the gut have learned ways to switch off pathways in gut epithelial cells that lead to switching on of genes involved in inflammation (Neish et al.). 相似文献
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Shav-Tal Y Darzacq X Shenoy SM Fusco D Janicki SM Spector DL Singer RH 《Science (New York, N.Y.)》2004,304(5678):1797-1800
Understanding gene expression requires the ability to follow the fate of individual molecules. Here we use a cellular system for monitoring messenger RNA (mRNA)expression to characterize the movement in real time of single mRNA-protein complexes (mRNPs) in the nucleus of living mammalian cells. This mobility was not directed but was governed by simple diffusion. Some mRNPs were partially corralled throughout the nonhomogenous nuclear environment, but no accumulation at subnuclear domains was observed. Following energy deprivation, energy-independent motion of mRNPs was observed in a highly ATP-dependent nuclear environment; movements were constrained to chromatin-poor domains and excluded by newly formed chromatin barriers. This observation resolves a controversy, showing that the energetic requirements of nuclear mRNP trafficking are consistent with a diffusional model. 相似文献
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Mathieu Diribarne Anne Vaiman Michel Péchayre E. Pailhoux Xavier Mata Gérard Guérin Stéphane Chaffaux 《Journal of Equine Veterinary Science》2009
Association of seven candidate genes with cryptorchidism was investigated in the Thoroughbred. A pedigree composed of 23 cryptorchids and 24 nonaffected horses, sharing a common ancestor, was constituted. Sixteen microsatellite markers were developed either from bacterial artificial chromosomes (BAC) isolated for each candidate gene or by in silico screening. DNA from our pedigree was genotyped for these microsatellites. Statistical analysis of the allelic and genotypic frequencies observed with these markers did not reveal any association between the candidate genes and the cryptorchidism phenotype in our horse panel. 相似文献