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101.
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
102.
103.
A neutralizing antibody selected from plasma cells that binds to group 1 and group 2 influenza A hemagglutinins 总被引:2,自引:0,他引:2
Corti D Voss J Gamblin SJ Codoni G Macagno A Jarrossay D Vachieri SG Pinna D Minola A Vanzetta F Silacci C Fernandez-Rodriguez BM Agatic G Bianchi S Giacchetto-Sasselli I Calder L Sallusto F Collins P Haire LF Temperton N Langedijk JP Skehel JJ Lanzavecchia A 《Science (New York, N.Y.)》2011,333(6044):850-856
The isolation of broadly neutralizing antibodies against influenza A viruses has been a long-sought goal for therapeutic approaches and vaccine design. Using a single-cell culture method for screening large numbers of human plasma cells, we isolated a neutralizing monoclonal antibody that recognized the hemagglutinin (HA) glycoprotein of all 16 subtypes and neutralized both group 1 and group 2 influenza A viruses. Passive transfer of this antibody conferred protection to mice and ferrets. Complexes with HAs from the group 1 H1 and the group 2 H3 subtypes analyzed by x-ray crystallography showed that the antibody bound to a conserved epitope in the F subdomain. This antibody may be used for passive protection and to inform vaccine design because of its broad specificity and neutralization potency. 相似文献
104.
Melosh NA Boukai A Diana F Gerardot B Badolato A Petroff PM Heath JR 《Science (New York, N.Y.)》2003,300(5616):112-115
We describe a general method for producing ultrahigh-density arrays of aligned metal and semiconductor nanowires and nanowire circuits. The technique is based on translating thin film growth thickness control into planar wire arrays. Nanowires were fabricated with diameters and pitches (center-to-center distances) as small as 8 nanometers and 16 nanometers, respectively. The nanowires have high aspect ratios (up to 10(6)), and the process can be carried out multiple times to produce simple circuits of crossed nanowires with a nanowire junction density in excess of 10(11) per square centimeter. The nanowires can also be used in nanomechanical devices; a high-frequency nanomechanical resonator is demonstrated. 相似文献
105.
Nanoscopically confined polymer films are known to exhibit substantially depressed glass transition temperatures (Lg's) as compared to the corresponding bulk materials. We report here that pentacene thin films grown on polymer gate dielectrics at temperatures well below their bulk Tg's exhibit distinctive and abrupt morphological and microstructural transitions and thin-film transistor (TFT) performance discontinuities at well-defined growth temperatures. The changes reflect the higher chain mobility of the dielectric in its rubbery state and are independent of dielectric film thickness. Optimization of organic TFT performance must recognize this fundamental buried interface viscoelasticity effect, which is detectable in the current-voltage response. 相似文献
106.
The ecological role and biogeochemical relevance of extracellular DNA in the oceanic sediments are unknown. Our global estimates indicate that up to 0.45 gigatons of extracellular DNA are present in the top 10 centimeters of deep-sea sediments, representing the largest reservoir of DNA in the world oceans. We demonstrate that extracellular DNA accounts for about one fifth of the total organic phosphorus regeneration and provides almost half of the prokaryotic demand for organic phosphorus. It therefore plays a key role in deep-sea ecosystem functioning on a global scale. 相似文献
107.
Johnson AP Cleaves HJ Dworkin JP Glavin DP Lazcano A Bada JL 《Science (New York, N.Y.)》2008,322(5900):404
Miller's 1950s experiments used, besides the apparatus known in textbooks, one that generated a hot water mist in the spark flask, simulating a water vapor-rich volcanic eruption. We found the original extracts of this experiment in Miller's material and reanalyzed them. The volcanic apparatus produced a wider variety of amino acids than the classic one. Release of reduced gases in volcanic eruptions accompanied by lightning could have been common on the early Earth. Prebiotic compounds synthesized in these environments could have locally accumulated, where they could have undergone further processing. 相似文献
108.
Treusch S Hamamichi S Goodman JL Matlack KE Chung CY Baru V Shulman JM Parrado A Bevis BJ Valastyan JS Han H Lindhagen-Persson M Reiman EM Evans DA Bennett DA Olofsson A DeJager PL Tanzi RE Caldwell KA Caldwell GA Lindquist S 《Science (New York, N.Y.)》2011,334(6060):1241-1245
Aβ (beta-amyloid peptide) is an important contributor to Alzheimer's disease (AD). We modeled Aβ toxicity in yeast by directing the peptide to the secretory pathway. A genome-wide screen for toxicity modifiers identified the yeast homolog of phosphatidylinositol binding clathrin assembly protein (PICALM) and other endocytic factors connected to AD whose relationship to Aβ was previously unknown. The factors identified in yeast modified Aβ toxicity in glutamatergic neurons of Caenorhabditis elegans and in primary rat cortical neurons. In yeast, Aβ impaired the endocytic trafficking of a plasma membrane receptor, which was ameliorated by endocytic pathway factors identified in the yeast screen. Thus, links between Aβ, endocytosis, and human AD risk factors can be ascertained with yeast as a model system. 相似文献
109.
Simone Palma Favaro Yardlei Carlos AlbaAnderson Dias Vieira de Souza Antonio Camilo Arguelho ViannaAntonia Railda Roel 《Scientia Horticulturae》2011
The purpose of this study was to evaluate the physico-chemical characteristics and the post-harvest loss of mass of curly lettuce (Lactuca sativa L.) cv. Verônica that was grown in a protective environment with applications of biopesticides. The curly lettuce was treated by spraying with neem oil, cassava flour wastewater (manipueira), biofertiliser or the control treatment of deltamethrin. We determined the weight, circumference, dry matter, ash, crude protein, total phenols and minerals profile for the heads of lettuce. After harvesting, the lettuce was packed into opened plastic bags and kept at 5 °C for 5 days to evaluate its weight loss. No differences were observed among the treatments for the physico-chemical parameters. The lettuce that was sprayed with manipueira or biofertiliser had the greatest weight loss during storage. The achievement of similar yields with cheaper products suggests a benefit of using organic bioinsecticides. 相似文献
110.
Sampedro I Aranda E Rodríguez-Gutiérrez G Lama-Muñoz A Ocampo JA Fernández-Bolaños J García-Romera I 《Journal of agricultural and food chemistry》2011,59(7):3239-3245
Byproducts generated from food industries, such as olive oil mills, have been studied to decrease harmful pollution and their environmental consequences. In this work, a new thermal pretreatment and saprobic fungal incubation to detoxify alperujo (two-phase olive mill waste) have been evaluated in view of its use as fertilizer in agriculture. The sequential use of both methods simplifies the thermal conditions and incubation times of the fungal treatment. Optimization of the thermal treatment from 150 to 170 °C for 45 and 15 min, respectively, reduced the incubation time with Coriolpsis rigida from 20 to 10 weeks needed to reduce phytotoxic effects on tomato plants. Therefore, the combination of thermal and biological treatments will allow the development of the potential benefits of alperujo to improve nutrients in agricultural soil. 相似文献