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排序方式: 共有825条查询结果,搜索用时 15 毫秒
821.
822.
Elizabeth León-García Gilber Vela-Gutiérrez Oscar A. Del Ángel-Coronel Cristobal Torres-Palacios Javier De La Cruz-Medina Miguel A. Gómez-Lim Hugo Sergio García 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(4):380-387
A healthy lifestyle includes fruits and vegetables consumption. Tomato is one of the most consumed vegetables, although it is susceptible to physical damage through postharvest handling, thus leading to important losses. Softening is an important variable during tomato ripening; excessive softening is undesirable and leads to postharvest losses. TomloxB plays an important role in ripening, mainly in the loss of cellular integrity caused by fatty acids released from the lipid matrix of membranes that initiate oxidative deterioration, which is in turn carried into senescence. In order to increase postharvest life, we produced transgenic tomato plants via Rhizobium radiobacter with tomato lipoxygenase B (TomloxB) antisense constructs under control of the cauliflower mosaic virus (CaMV) 35S promoter. Lipoxygenase activity and firmness were measured in tomato fruit and the fatty acids profile was determined. Transgenic fruits were maintained for 40 days at room temperature in optimal conditions, whereas wild type fruits remained in similar conditions for only six days. Firmness in pink and red stages was significantly lower in wild type fruits than in two transgenic lines. Linolenic acid was the most important fatty acid consumed by lipoxygenase in both turning and pink stages of ripening. Lipoxygenase activity was smaller in transformed fruits in comparison with the wild type. These results suggest that silencing the TomloxB gene promoted significant changes in the physiology of transformed tomatoes, being the increase in postharvest life the most important. 相似文献
823.
Rodrigo Javier Vargas Silvia Maria Guimarães de Souza Alexandre Melo Kessler & Sueli Regina Baggio 《Aquaculture Research》2008,39(6):657-665
The jundiá (Rhamdia quelen) is a siluriform with great potential for aquaculture in South America. Fish oil is a raw material in diets for fish. However, the fisheries that provide fish oil have reached their limit of sustainability. Thus, the use of alternative sources for this ingredient is primordial. The aim of this study was to evaluate the performance and body composition of the jundiá fed with different sources of the vegetable oils. Jundiá (1.0±0.2 g) were fed for 31 days with five isonitrogenous (37%) and isoenergetic (19 kJ g?1) diets, in which the following oils were added: 50 g kg?1 corn oil (CO), 50 g kg?1 fish oil (FO), 50 g kg?1 linseed oil (LO), 33.4 g kg?1 fish oil and 16.7 g kg?1 linseed oil (1/3LO), 16.7 g kg?1 fish oil and 33.4 g kg?1 linseed oil (2/3LO). The performance did not show differences between treatments. The final fatty acid profile and n‐3/n‐6 ratio of the fish were highly influenced by the diet. Fish‐fed diets with linseed and/or fish oil showed superior n‐3/n‐6 ratios to the minimal recommended by the World Health Organization; whereas fish fed diets with corn oil showed an inferior value. Albeit in the present study the commercial size of fish was not attained, these results show a clear tendency. The desaturation/elongation capacity was evidenced, in this species, for the first time. Linseed oil can be utilized as a substitute for fish oil in diets of jundiá without affecting their performance and for producing good‐quality fish. However, more studies are necessary to confirm these results for commercial size. 相似文献
824.
Luciano Lazzarini Wolff Edson Fontes de Oliveira Javier Lobón-Cerviá 《Ecology of Freshwater Fish》2023,32(1):195-208
Fish ecomorphological analyses often deal with several traits simultaneously, making it challenging to interpret general patterns, and have not addressed the longitudinal component of streams in morphology-habitat relationships. We identified ecomorphotypes of fishes and correlated their morphological variation with food, structural/hydrological variables, and abundances to detect their links with diet and local-scale habitat categories. Eighteen morphometric traits were obtained from specimens collected by electrofishing in a coastal Atlantic stream in Brazil. To test for morphology-habitat associations, headwaters, middle, and mouth reaches were divided into shorter sampling sites, with the middle reach being classified into riffle, run, and pool mesohabitats. Multivariate analyses highlighted the morphological variations and associated the form categories of 18 fish species with food and habitat categories. It resulted in four combined trophic and habitat ecomorphotypes: (1) benthic AB/lithophilic, composed of smaller to longer loricariids, detritivores, of fast-water, and pebbly habitats; (2) benthic C/lithophilic of very fast-waters, algal and detritus scrapers, with longer intestines than the other benthic species, wider suctorial mouths, inhabitants of headwaters, and riffles habitats; (3) nektobenthic/lithophilic with streamlined bodies, invertebrate feeders, and dwellers of faster-water, cobbly habitats; and (4) nektonic/limnophilic composed mainly by characins, which had strong correlations with terrestrial insect consumption, and lentic/pool, sandy habitats. The morphology–environment correlations linked these ecomorphotypes to the broad habitat gradient arrayed in longitudinal and local scales. These results permit inferring the larger form patterns expected for local fish assemblages and emphasise the fish trait categorisation as a possible surrogate to reveal broader ecomorphological associations. 相似文献
825.
Tortilla chips were slow dried after baking and then fried in fresh soybean oil. Control chips were not dried before frying. Final oil content of sun-dried tortilla chips was significantly (P < 0.05) lower than those receiving the control treatment. As a result of drying, the structure of the tortilla chips was tighter before frying but expanded significantly during frying. An attempt was made to produce tortilla chips with the same characteristics of the sun-dried chips using impinging hot-air drying techniques. Results indicated that tortilla chips drying rate was mostly affected by air temperature; texture was crispier at higher air temperatures; shrinkage of the piece was higher at lower convective heat transfer coefficient; and microstructure looked smoother at higher air temperature. 相似文献