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941.
Artur Dzialuk Małgorzata Mazur Krystyna Boratyńska Jose M. Montserrat Angel Romo Adam Boratyński 《Annals of Forest Science》2011,68(8):1341-1350
• Introduction, Material and Methods
The genetic structure and diversity of ten natural populations of Juniperus phoenicea L. from the western part of the species range have been studied using random amplified polymorphic DNA (RAPD) markers. 相似文献942.
Carlos?A.?Acu?aEmail author Ann?R.?Blount Kenneth?H.?Quesenberry Kevin?E.?Kenworthy Wayne?W.?Hanna 《Euphytica》2011,179(2):227-235
Manipulating apomixis for fixing tetraploid bahiagrass (Paspalum notatum Flüggé) hybrids exhibiting superior agronomic characteristics would be a valuable tool for the genetic improvement of this
species. The objectives were to create a second generation of hybrids by crossing sexual first-generation tetraploid hybrids
(FGTH) and unrelated apomictic FGTH or ecotypes, determine the segregation for mode of reproduction, and estimate the resulting
genetic variation and heterosis for several agronomic characteristics. The segregation for mode of reproduction was analyzed
using mature embryo sac observations. Field measurements and visual ratings were used to evaluate the growth habit, production
of inflorescences, cool-season growth and freeze resistance of hybrids. A ratio of 4.6:1 between sexual and apomictic hybrids
was observed. Only 3% of the progeny was classified as highly apomictic. The low proportion of highly apomictic progeny restricts
the feasibility of this breeding approach. Large genetic variation was observed among hybrids for growth habit, cool-season
growth and freeze resistance. The proportion of hybrids exhibiting heterosis was high for plant height, cool-season growth,
and freeze resistance. The tetraploid bahiagrass germplasm contains a large diversity for traits of agronomic importance that
can be exploited for the genetic improvement of this species. 相似文献
943.
Alejandro Bernardo Falcón-Rodríguez Daimy Costales Juan Carlos Cabrera Miguel Ángel Martínez-Téllez 《Pesticide biochemistry and physiology》2011,100(3):221-228
Enzymatic defense responses and protection against Phytophthora nicotianae were studied in tobacco plants treated with chitosan of different molecular weights (MW) and degrees of acetylation (DA). The concentration and mode of chitosan application affected enzymatic induction in tobacco leaves. β-1,3-Glucanase (EC 3.2.1.6) activity required 10 times the polymer concentration relative to the oligochitosan mixture to induce the highest activity above control when treated by foliar spray, indicating the influence of molecular weight in this response. PAL (EC 4.3.1.5) and POD (EC 1.11.1.6) activities increased above control as a result of the influence of polymer degree of acetylation when treatments were applied by foliar spray. A higher DA favored PAL activity, whereas a lower DA induced higher POD activity. Using an in vitro bioassay, it was found that the three chitosan compounds caused a reduction of the infection index of P. nicotianae in tobacco plants that was dependent on elicitor concentrations. There was a significant relationship between the reduction of the infection index and an increase in PAL activity when chitosan was applied by foliar spray and by substrate drench to the plant rhizosphere. These results demonstrate the influence of chitosan physico–chemical properties in plant-induced resistance and the relevance of particular responses in plant protection against pathogens. 相似文献
944.
Rosalía Núñez-Pastrana Guadalupe Fabiola Arcos-Ortega Ramón Armando Souza-Perera Carlos Alberto Sánchez-Borges Yumi Elena Nakazawa-Ueji Francisco Javier García-Villalobos Adolfo Alberto Guzmán-Antonio José Juan Zúñiga-Aguilar 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(4):669-683
945.
Felipe André Sganzerla Graichen José Antônio Martinelli Caroline de Lima Wesp Luis Carlos Federizzi Márcia Soares Chaves 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(3):497-510
Crown rust, caused by Puccinia coronata f. sp. avenae, can cause significant damage in all regions where oats (Avena sativa L.) are cultivated. The primary means of controlling crown rust has been through genetic resistance, although in most cases
resistance has been quickly overcome by the pathogen. More durable partial or non-specific resistance may possess different
mechanisms from those underlying genes with specific effects. We studied the epidemiological and histological components of
crown rust resistance with potential use in plant protection. Among the components evaluated, pustule density showed the clearest
effect on resistance, while the latent period was not an important component. Cell death associated with the accumulation
of autofluorescent and phenolic compounds was common in the resistant genotypes, but temporally distinct for the genotypes
studied. Genotype Pc68/5*Starter, which has race-specific resistance, showed rapid cell death that prevented the development
of pathogen colonies. Conversely, with cultivar URS 21 and genotypes 04B7113-1 and 04B7119-2, cell death and associated accumulation
of autofluorescent and phenolic compounds was delayed until pathogen colonies were already established. Pathogen colonies
developed normally in susceptible plants genotypes, and had usually produced sporogenic tissue by 5 days after inoculation.
The data suggest that the resistance mechanisms, especially hypersensitivity and phenolic compound production, active in resistant
plants are similar but may be differently expressed over time. The temporal variation in the expression of hypersensitivity
and phenolic compound production reflects the level of field resistance in these genotypes. 相似文献
946.
Jose M. Espuny Tomas Dolores M. Simon-Pujol F. Congregado G.Suarez Fernandez 《Soil biology & biochemistry》1982,14(6):557-560
The influence of 457 bacteria isolated from soil on spore germination by Aspergillus flavus was studied by light and scanning microscopy. Bacteria were found to be in physical association with the fungus. The bacteria were tested for antagonism against 11 fungal phytopathogens. A number of the bacterial antagonists displayed a wide spectrum in their activity against the fungi. 相似文献
947.
Tillage-induced soil erosion or redistribution increases spatial variation of several soil properties and often reduces the productive capacity of soil resources. Our objectives were to identify the extent of this type of erosion by observing the changes in soil morphological properties in the field and analysing its possible effects on soil productivity. The study was initiated in 2001 and conducted at two irrigated sites located approximately at Terena, Alandrol, 80 km east of Évora, Portugal. They were planted to corn (Zea mays L.) during this study, but have a long history of agricultural use with a trend toward increasing intensity in recent years. Soils in the field studies are classified mainly as Calcaric Regosols, Calcaric Cambisols, Luvisols and small areas of Fluvisols. The amount of erosion was estimated by simulation and verified by describing the lithology and measuring soil carbonates. The presence of carbonates in the superficial Ap horizons of soils that were previously devoid of this compound, provide evidence of soil redistribution: (1) in soils derived from calcareous parent material, this is the result of a re-carbonation process; (2) in soils derived from non-calcareous parent material the presence of carbonates in the superficial Ap horizons results from a carbonation process. On both sites, A and B, approximately 17% of the soils sampled were either carbonated or re-carbonated. Carbonation and re-carbonation of soil profiles confirmed that tillage had redistributed the soil-ploughing layer over time. Decreased corn yield was also observed as slope increase. If current agricultural practices are continued in this area, a decrease in soil quality and maximum yield on higher slopes can be expected. 相似文献
948.
Edurne Aguiriano Magdalena Ruiz Rosario Fité Jose M. Carrillo 《Genetic Resources and Crop Evolution》2006,53(8):1543-1552
In this work gliadin proteins were used to analyse the genetic variability in a sample of the durum wheat Spanish collection
conserved at the CRF-INIA. In total 38 different alleles were identified at the loci Gli-A1, Gli-A3, Gli-B5, Gli-B1, Gli-A2 and Gli-B2. All the gliadin loci were polymorphic, possessed large genetic diversity and small and large differentiation within and
between varieties, respectively. The Gli-A2 and Gli-B2 loci were the most polymorphic, the most fixed within varieties and the most useful to distinguish among varieties. Alternatively,
Gli-B1 locus presented the least genetic variability out of the four main loci Gli-A1, Gli-B1, Gli-A2 and Gli-B2. The Gli-B1 alleles coding for the gliadin γ-45, associated with good quality, had an accumulated frequency of 69.7%, showing that the
Spanish germplasm could be a good source for breeding quality. The Spanish landraces studied showed new gliadin alleles not
catalogued so far. These new alleles might be associated with specific Spanish environment factors. The large number of new
alleles identified also indicates that durum wheat Spanish germplasm is rather unique. 相似文献
949.
Jiménez JB Orea JM Montero C Ureña AG Navas E Slowing K Gómez-Serranillos MP Carretero E De Martinis D 《Journal of agricultural and food chemistry》2005,53(5):1526-1530
Resveratrol is known as a grapevine secondary metabolite with fungicide activity. Its exogenous application on harvested grapes resulted in the reduction of microbial flora growth, and consequently, prolonged shelf life, without affecting the nutritional quality of the fruit. Resveratrol treatment also resulted in being effective on fruit that normally does not accumulate such metabolites as, for example, tomatoes, apples, avocado pears, and peppers. As a result, all treated fruits maintained their post-harvest quality and health longer than the untreated ones. This study demonstrates the potential use of resveratrol as a natural pesticide to reduce post-harvest fungi development on a broad spectrum of fruit types. 相似文献
950.
Mortier L Huet AC Daeseleire E Huyghebaert G Fodey T Elliott C Delahaut P Van Peteghem C 《Journal of agricultural and food chemistry》2005,53(18):7142-7149
Anticoccidials are compounds that are widely used as feed additives to prevent and treat coccidiosis. They are licensed for use in a prescribed concentration and during a certain time interval for broilers and pullets but not for laying hens. It was shown in the past that carry-over at the feeding mill is found to be the main reason for the presence of residues in eggs. An animal experiment was set up to investigate the effect of carry-over at the feeding mill on the presence of residues of anticoccidials in eggs. For the compounds diclazuril, robenidine, halofuginone and nicarbazin in combination with narasin, two concentration levels were tested: the maximum allowed concentration for broilers (100%) and a concentration corresponding to 5% carry-over during feed preparation. Also dimetridazole was included in the experiment but only at one concentration level. Eggs were sampled during treatment (14 days) and for a period of 30 days after withdrawal of the anticoccidial-containing feed. Residues were determined, and deposition and depletion curves were generated. Analyses were performed by ELISA and LC-MS/MS. For all compounds, substantial residues could be found in the 5% groups, which points out the risk of carry-over at the feeding mill. The distribution of the residues between egg yolk and white was determined by analyzing both fractions. 相似文献