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961.
Dapeng Zhang Windson July Martínez Elizabeth S. Johnson Eduardo Somarriba Wilberth Phillips-Mora Carlos Astorga Sue Mischke Lyndel W. Meinhardt 《Genetic Resources and Crop Evolution》2012,59(2):239-252
Cacao (Theobroma cacao L.) is an important economic crop in the Bolivian Amazon. Bolivian farmers both cultivate cacao, and extract fruits from
wild stands in the Beni River region and in valleys of the Andes foothills. The germplasm group traditionally used is presently
referred to as “Cacao Nacional Boliviano” (CNB). Using DNA fingerprinting technology based on microsatellite markers, we genotyped
164 Bolivian cacao accessions, including both cultivated and wild CNB accessions sampled from the Amazonian regions of La
Paz and Beni, and compared their SSR profiles with 78 reference Forastero accessions from Amazonian cacao populations, including
germplasm from the Ucayali region of Peru. Results of multivariate ordination and analysis of molecular variance show that
CNB cacao has a unique genetic profile that is significantly different from the known cacao germplasm groups in South America.
The results also show that cultivated CNB and wild CNB populations in the Beni River share a similar genetic profile, suggesting
that the cultivated CNB is of indigenous origin in Bolivia. The level of genetic diversity, measured by allele richness and
gene diversity in the Bolivian cacao, is moderately high, but was significantly lower than gene diversity in the other Amazonian
cacao populations. Significant spatial genetic structure was detected in the wild CNB population, using analysis of autocorrelation
(rc = 0.232; P < 0.001) and Mantel tests (Rxy = 0.276; P < 0.001). This finding is also highly valuable to support in situ conservation and sustainable use of CNB genetic diversity in Bolivia. 相似文献
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Daniel J Andrade Rosangela S Falconi Diego S Siqueira Crislany L Barbosa Antonio S Ferraudo Carlos AL Oliveira 《Pest management science》2013,69(1):81-87
BACKGROUND: Leprosis is one of the most serious citrus plant diseases. Leprosis‐affected plants, especially sweet orange [Citrus sinensis (L.) Osbeck], which is the most widely cultivated citrus fruit worldwide, show reduced photosynthetic capacity and severe defoliation. The aim was to evaluate the relationship between the Brevipalpus phoenicis (Geijskes) vector mite and citrus leprosis disease in Pera sweet orange plants grafted on different rootstocks. Data were analysed using numerical classification and conventional statistical analysis (ANOVA). RESULTS: Both viruliferous and non‐viruliferous B. phoenicis populations increased in number on plants maintained at low soil water content. Among the evaluated rootstocks, Sunki mandarin proved least favourable for mite population increase. Furthermore, the viruliferous mite population increased more rapidly than the non‐viruliferous mite population. CONCLUSION: The Cleopatra rootstock showed low variability in leaf nitrogen content, low mite number and low leprosis severity, thereby producing the most favourable results. Under appropriate moisture conditions, the Sunki rootstock produced the best results, showing the least severe leprosis. Rangpur lime rootstock grown in soil with varying water content showed the greatest variation in foliar nitrogen content, mite number and severity of leprosis and is considered to be the most difficult rootstock to manage. Copyright © 2012 Society of Chemical Industry 相似文献
965.
Adrian Ponce de León Door Alejandro Romo Chacón Carlos Acosta Muñiz. 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(2):223-229
Fire blight, one of the most severe diseases of apple and pear, is caused by the bacterium Erwinia amylovora. One control method is the use of antibiotics like streptomycin; however, streptomycin is the only antibiotic registered to control fire blight. A total of 107 E. amylovora strains were isolated from apple orchards located in Cuauhtémoc and Guerrero, Chihuahua, two major apple-producing areas in Mexico, showing 40 and 24 % streptomycin-resistant strains, respectively. The identification of E. amylovora strains was performed by polymerase chain reaction (PCR) amplification of a 900-bp region located within the non-transferable pEA29 plasmid and by amplification of a specific 1,269-bp region located on the E. amylovora chromosome. The 107 isolates tested carried the pEA29 plasmid, and 36 % of the isolates from both locations showed high resistance to streptomycin at levels that ranged from 200 to ≥1,000 μg ml?1 streptomycin. The strA-strB and aadA genes, which encode enzymes that inactivate streptomycin, and a mutation in codon 43 of the rpsL gene that confers high resistance to the antibiotic were examined to determine the mechanism of streptomycin resistance. In total, 95 % of the resistant strains showed a single base pair mutation in codon 43 of the rpsL gene, causing an amino acid substitution in ribosomal protein S12. The presence of strA-strB and aadA genes or the rpsL mutation was not identified in the other 5 % of resistant strains, suggesting the existence of a new streptomycin resistance mechanism in E. amylovora. 相似文献
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The prevailing paradigm states that cancer cells acquire multiple genetic mutations in oncogenes or tumor suppressor genes whose respective activation/up-regulation or loss of function serve to impart aberrant properties, such as hyperproliferation or inhibition of cell death. However, a tumor is now considered as an organ-like structure, a complex system composed of multiple cell types (e.g., tumor cells, inflammatory cells, endothelial cells, fibroblasts, etc.) all embedded in an inflammatory stroma. All these components influence each other in a complex and dynamic cross-talk, leading to tumor cell survival and progression. As the microenvironment has such a crucial role in tumor pathophysiology, it represents an attractive target for cancer therapy. In this review, we describe the mechanism of action of trabectedin and plitidepsin as an example of how these specific drugs of marine origin elicit their antitumor activity not only by targeting tumor cells but also the tumor microenvironment. 相似文献
969.
Soledad Morillo-García Nerea Valcárcel-Pérez Andrés Cózar María J. Ortega Diego Macías Eduardo Ramírez-Romero Carlos M. García Fidel Echevarría Ana Bartual 《Marine drugs》2014,12(3):1438-1459
Diatoms, a major component of the large-sized phytoplankton, are able to produce and release polyunsaturated aldehydes after cell disruption (potential PUAs or pPUA). These organisms are dominant in the large phytoplankton fraction (>10 µm) in the Strait of Gibraltar, the only connection between the Mediterranean Sea and the Atlantic Ocean. In this area, the hydrodynamics exerts a strong control on the composition and physiological state of the phytoplankton. This environment offers a great opportunity to analyze and compare the little known distribution of larger sized PUA producers in nature and, moreover, to study how environmental variables could affect the ranges and potential distribution of these compounds. Our results showed that, at both tidal regimes studied (Spring and Neap tides), diatoms in the Strait of Gibraltar are able to produce three aldehydes: Heptadienal, Octadienal and Decadienal, with a significant dominance of Decadienal production. The PUA released by mechanical cell disruption of large-sized collected cells (pPUA) ranged from 0.01 to 12.3 pmol from cells in 1 L, and from 0.1 to 9.8 fmol cell−1. Tidal regime affected the abundance, distribution and the level of physiological stress of diatoms in the Strait. During Spring tides, diatoms were more abundant, usually grouped nearer the coastal basin and showed less physiological stress than during Neap tides. Our results suggest a significant general increase in the pPUA productivity with increasing physiological stress for the cell also significantly associated to low nitrate availability. 相似文献
970.
Alonso Pardo-Vargas Ingrid de Barcelos Oliveira Paulo Roberto Soares Stephens Claudio Cesar Cirne-Santos Izabel Christina Nunes de Palmer Paix?o Freddy Alejandro Ramos Carlos Jiménez Jaime Rodríguez Jackson Antonio Lamounier Camargos Resende Valeria Laneuville Teixeira Leonardo Castellanos 《Marine drugs》2014,12(7):4247-4259