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101.
102.
Muegge BD Kuczynski J Knights D Clemente JC González A Fontana L Henrissat B Knight R Gordon JI 《Science (New York, N.Y.)》2011,332(6032):970-974
Coevolution of mammals and their gut microbiota has profoundly affected their radiation into myriad habitats. We used shotgun sequencing of microbial community DNA and targeted sequencing of bacterial 16S ribosomal RNA genes to gain an understanding of how microbial communities adapt to extremes of diet. We sampled fecal DNA from 33 mammalian species and 18 humans who kept detailed diet records, and we found that the adaptation of the microbiota to diet is similar across different mammalian lineages. Functional repertoires of microbiome genes, such as those encoding carbohydrate-active enzymes and proteases, can be predicted from bacterial species assemblages. These results illustrate the value of characterizing vertebrate gut microbiomes to understand host evolutionary histories at a supraorganismal level. 相似文献
103.
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105.
Amyloidosis induced in mice by Escherichia coli endotoxin 总被引:7,自引:0,他引:7
Amyloidosis was produced in mice by repeated subcutaneous injections of 0.5-or 0.005-milligram amounts of Escherichia coli endotoxin. Of the two strains of mice examined, amyloidosis was induced more readily in one than in the other. The ability of endotoxin to induce amyloidosis lends support to the view that stimulation of reticuloendothelial cells leads to amyloid formation. 相似文献
106.
Erythropoiesis in the rat: differential rates of DNA synthesis and cell proliferation 总被引:2,自引:0,他引:2
F C Monette J LoBue A S Gordon P Alexander P C Chan 《Science (New York, N.Y.)》1968,162(858):1132-1134
Direct in vivo estimates of DNA synthesis time in early and late erythroblasts were obtained by using the H(3)- and C(14)-thymidine double-la-beling technique. A double-emulsion autoradiographic procedure was used to resolve the two isotopes. Early erythroblasts were found to proliferate at a rate about five times that of late cells. This results primarily from a shorter mean DNA synthesis time in early cells (2.5 hours) than in late cells (6.5 hours). 相似文献
107.
The retina of the newborn human infant 总被引:2,自引:0,他引:2
I Abramov J Gordon A Hendrickson L Hainline V Dobson E LaBossiere 《Science (New York, N.Y.)》1982,217(4556):265-267
We have examined a pair of eyes from a normal, full-term infant who died at 8 days as a result of accidental injury. Eyes were obtained immediately after death, fixed, and sectioned for light microscopy. Results from both eyes were substantially the same. The macular region was still drastically immature at 1 week. Even though a foveal depression existed, all cell layers were still present across it. Furthermore, the inner nuclear layer was divided into two separate layers. The receptor layer was reduced to one or two cells thick; receptors had both inner and outer segments, but they were very short and stumpy. The region of immaturity covered about 5 degrees of the retina. These findings suggest that the central region of a human infant's retina is probably not fully functional at birth. 相似文献
108.
Integration and stable germ line transmission of genes injected into mouse pronuclei 总被引:27,自引:0,他引:27
Genetic material has been successfully transferred into the genomes of newborn mice by injection of that material into pronuclei of fertilized eggs. Initial results indicated two patterns of processing the injected DNA: one in which the material was not integrated into the host genome, and another in which the injected genes became associated with high molecular weight DNA. These patterns are maintained through further development to adulthood. The evidence presented indicates the covalent association of injected DNA with host sequences, and transmission of such linked sequences in a Mendelian distribution to two succeeding generations of progeny. 相似文献
109.
Hovis WA Clark DK Anderson F Austin RW Wilson WH Baker ET Ball D Gordon HR Mueller JL El-Sayed SZ Sturm B Wrigley RC Yentsch CS 《Science (New York, N.Y.)》1980,210(4465):60-63
The Coastal Zone Color Scanner (CZCS) on Nimbus-7, launched in October 1978, is the only sensor in orbit that is specifically designed to study living marine resources. The initial imagery confirms that CZCS data can be processed to a level that reveals subtle variations in the concentration of phytoplankton pigments. This development has potential applications for the study of large-scale patchiness in phytoplankton distributions, the evolution of spring blooms, water mass boundaries, and mesoscale circulation patterns. 相似文献
110.
Submarine thermal sprirngs on the galapagos rift 总被引:2,自引:0,他引:2
Corliss JB Dymond J Gordon LI Edmond JM von Herzen RP Ballard RD Green K Williams D Bainbridge A Crane K van Andel TH 《Science (New York, N.Y.)》1979,203(4385):1073-1083
The submarine hydrothermal activity on and near the Galápagos Rift has been explored with the aid of the deep submersible Alvin. Analyses of water samples from hydrothermal vents reveal that hydrothermal activity provides significant or dominant sources and sinks for several components of seawater; studies of conductive and convective heat transfer suggest that two-thirds of the heat lost from new oceanic lithosphere at the Galápagos Rift in the first million years may be vented from thermal springs, predominantly along the axial ridge within the rift valley. The vent areas are populated by animal communities. They appear to utilize chemosynthesis by sulfur-oxidizing bacteria to derive their entire energy supply from reactions between the seawater and the rocks at high temperatures, rather than photosynthesis. 相似文献