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71.
Teresa P. Caams Immaculada Vias Josep Usall Rosario Torres Marina Anguera Neus Teixid 《Postharvest Biology and Technology》2008,49(1):96-106
Infection of citrus fruit by postharvest pathogens often occurs in the field prior to harvest; therefore, it could be advantageous to apply biocontrol agents before harvest, which would reduce initial infection and then remain active and control pathogens in storage and under commercial conditions. The objective of the present work was to evaluate the effectiveness of different formulations of Pantoea agglomerans applied preharvest for controlling postharvest diseases on citrus. Results confirmed the protective effect of the additive Fungicover (FC) on populations of P. agglomerans exposed to non-conducive field conditions. In general, when osmotic-adapted and lyophilised P. agglomerans cells were used in bacterial treatments, these treatments showed greater survival rates than treatments with non-osmotic-adapted or fresh cells under field conditions. However, this superiority was only found when Fungicover was also added to suspensions of bacterial treatments. Therefore, bacterial treatments with Fungicover had population levels of P. agglomerans cells 1.2 and 2.8 log CFU cm−2 higher than bacterial treatments without Fungicover during field experiments. These results allowed us to conclude that it is possible to improve environmental stress tolerance and ecological competence of P. agglomerans cells by integrating certain formulation strategies. Consequently, the improved formulation of P. agglomerans provided an effective control for orange fruit against natural postharvest pathogen infections and artificial infections of Penicillium digitatum with values of decay reduction higher than 50%. These latter results also demonstrated that it is possible to control postharvest pathogens using bacterial preharvest treatments. 相似文献
72.
"食品毒理学"动物实验通常需要使用较多实验动物给予毒物处理以满足课堂教学的需要,当前,飞速发展的信息时代下,各种新型教学技术手段极大地变革了高校实验课的教学形态。虚拟仿真实验教学系统和问卷星这2种新型教学手段相结合的方式,能够更加高效地辅助"食品毒理学"完成实验教学,提高教学效率,最大程度减少实验动物使用量,从而加深学生对于毒理学动物实验所倡导的3R (替代Reduction,减少Replacement,优化Refinement)原则的认识。 相似文献
73.
“食品工程原理”课程在食品类专业学生工程能力培养中起着重要的作用。在分析前期教学问题的基础上,围绕教学内容、方法、技巧和手段等进行了以提高学生工程能力为目的的课程教学实践与探索,旨在为提高该课程教学质量提供一定参考。 相似文献
74.
"食品感官评定"与实际生产联系非常紧密,具有很强的实用性。传统教学多采用课堂讲授的教学方式,灌输多启发少,以学习理论知识为主,不能很好地做到理论与实践的紧密结合。教研团队针对"食品感官评价"课程的特点,在教学过程中实施案例教学法,不仅能实现学生更好地掌握理论知识,还能够调动其学习积极性,加强学生对所学知识的理解,帮助学生理论联系实践。 相似文献
75.
Worldwide, many nations impose blending of their transport fuels with biofuels, approximating 10% globally by 2020, to contribute to energy security while reducing emission of green house gasses (GHG). Food riots, scientific insights that question the GHG benefits and raised concern about the loss of biodiversity, have lead to the formulation by various governments of sustainability criteria for biofuels to comply with. In this paper, we assess this conditionality and argue that large-scale biofuels production will be unable to comply with these criteria in 2020, and can therefore not be qualified as sustainable. 相似文献
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79.
Lisa Bjørnlund Søren Mørk Mette Vestergård Regin Rønn 《Biology and Fertility of Soils》2006,43(1):1-11
The aim was to study the effects of P fertilization and leaf aphid attack on the trophic interactions of bacteria and bacterial feeders in the rhizospheres of barley plants. The density of protozoa peaked in the rhizospheres of plants fertilized with N and P, whereas nematodes peaked in the rhizospheres of plants to which only N had been added. Fingerprinting of bacterial communities by length heterogeneity polymerase chain reaction revealed differences in community structure between NP rhizospheres and N rhizospheres as well as aphid-related differences within N rhizospheres. Specifically, α-proteobacteria increased with P addition. To evaluate if differences in bacteria in terms of their quality as food could partly explain the observed differences in protozoan and nematode abundances, growth of the flagellate Cercomonas sp. was assessed with 935 bacteria isolated from the different treatments. This assay indicated that bacterial isolates were of higher food quality to Cercomonas sp. in NP than in N rhizospheres when plants were subjected to aphid attack. Bacteria of high and low food quality for Cercomonas sp., respectively, were fed to the nematode Caenorhabditis elegans and larval production examined. α-Proteobacteria supported the growth of Cercomonas sp. well, whereas Actinobacteria did not. In contrast, C. elegans reproduced poorly on most α-proteobacteria but were able to reproduce well on some Actinobacteria. These results suggest that the different response of protozoa and nematodes to P addition could be mediated through a food quality-related change in community composition of bacteria and that leaf aphid attack may interfere with nutrient effects on bacterial assemblages of rhizospheres. 相似文献
80.
Liliane Ruess Alexei Tiunov Dominique Haubert Max M. Häggblom 《Soil biology & biochemistry》2005,37(5):945-953
Stable isotope analysis has been used as a powerful tool in food web studies in terrestrial ecosystems. In addition the occurrence and abundance of fatty acids may serve as indicator for feeding strategies of soil animals. Here we combine both approaches and investigate the fatty acid composition, δ13C values of bulk tissues and individual fatty acids in soil organisms. The fungi Chaetomium globosum and Cladosporium cladosporioides were isotopically labelled by fructose derived from either C3 or C4 plants, and the fungal-feeding nematode Aphelenchoides sp. was reared on C. globosum. Fungi and nematodes were used as diet for the Collembolan Protaphorura fimata. The sugar source was fractionated differently by fungal lipid metabolism in a species-specific manner that points to a sensitivity of physiological processing to the non-random distribution of 13C/12C isotopes in the molecule. As a general trend stearic acid (18:0) was depleted in 13C compared to the precursor palmitic acid (16:0), whereas its desaturation to oleic acid (18:1 ω9) favoured the 13C-rich substrate.Fatty acid profiles of P. fimata varied due to food source, indicating incorporation of dietary fatty acids into Collembolan tissue. Individuals feeding on fungi had lower amounts in C20 fatty acids, with monoenoic C20 forms not present. This pattern likely separates primary consumers (fungivores) from predators (nematode feeders). The isotopic discrimination in 13C for bulk Collembola ranged between −2.6 and 1.4‰ and was dependent on fungal species and C3/C4 system, suggesting differences at metabolic branch points and/or isotope discrimination of enzymes. Comparison of δ13C values in individual fatty acids between consumer and diet generally showed depletion (i.e. de novo synthesis) or no changes (i.e. dietary routing), but the fractionation was not uniform and affected by the type of ingested food. Fatty acid carbon isotopes were more variable than those of bulk tissues, likely due to both the distrimination by enzymes and the different lipid origin (i.e. neutral or polar fraction). 相似文献