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81.
A cross-sectional study was conducted to determine the seroprevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to investigate the risk factors related to antibodies against T. gondii and N. caninum in dogs of the city of Campina Grande, state of Paraiba, Northeast region of Brazil. For this purpose, 286 blood samples were collected from dogs during the rabies vaccination campaign, in September 2003, and on this occasion questionnaires addressing epidemiological aspects of the infections were given to each dog owner. The sera were analyzed for anti-T. gondii and anti-N. caninum antibodies by indirect fluorescent antibody tests. Of the total of 286 dogs, 129 were positive for T. gondii (titer16) with a prevalence value of 45.1% (95% CI=39.24-51.07%). For N. caninum, 24 dogs were positive (titer50), with a prevalence value of 8.4% (95% CI=5.45-12.23%). Antibodies to T. gondii and N. caninum were found simultaneously in 14 dogs (4.9%; 95% CI=2.7-8.08%). For T. gondii infection, the risk factors associated with seroprevalence was the age of the animals, with dogs older than one year presenting higher values of odds ratio, and co-habitation of cats in the household. For N. caninum infection, dogs that have street contact had higher odds of seropositivity than dogs that remained exclusively in a domestic environment.  相似文献   
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In silvopasture system, the coexistence of eucalyptus seedlings with other species may result in growth reduction, especially during eucalyptus early development.Therefore, studies elucidating how forage species affect the eucalyptus growth can provide important information for their rational management aiming to obtain the maximum gain of the system. The aim of this work was to evaluate the effect of increasing densities of Urochloa brizantha cv.Marandu in the early development of Eucalyptus urograndis. An experiment was conducted in 20 L pots, in an open and semi-controlled area, during 90 days after planting of eucalyptus. A completely randomized design with four replications was used, in a 6 9 7 factorial system, meaning six evaluation periods and seven densities of U. brizantha: 0(control), 22, 33, 44, 67, 89 and111 plants m-2. Fortnightly, eucalyptus height, stem diameter and chlorophyll fluorescence(Fv/Fm) were evaluated. At the end of experimental period, the net assimilation rate, stomatal conductance and transpiration rate of eucalyptus plants were determined, in addition to the dry matter of eucalyptus(leaves and stem) and U. brizantha (leaves). In coexistence with 111 plants m-2, eucalyptus had reduction of 63.9% on total dry matter and 72.7% on leaf area, compared to the control. From the density of22 plants m-2, U. brizantha negatively interfere significantly the growth of E. urograndis. Up to 8 plants m-2 there are no reductions greater than 5% in eucalyptus height and stem diameter.  相似文献   
84.
The coffee leaf miner, Leucoptera coffeella, is the most important pest of Coffea arabica plantations in Brazil, and all cultivars are susceptible to the insect. However, distinct reactions have been observed in other species, such as C. congensis and C. canephora. In this work, the occurrence of antixenotic response was surveyed in individuals of Coffea species, selected for resistance to the leaf miner at both field and laboratory conditions. Tests performed on young plants from C. arabica cultivars Icatu Precoce IAC 3282, Mundo Novo IAC 515-20, Tupi IAC 1669-33 and Catuaí Amarelo IAC 62 demonstrated that these were preferred for oviposition when pooled with seedlings from C. canephora cv. Apoat? IAC 2258. Apoat? was also preferred over C. racemosa for oviposition. Similar results were observed in tests using detached leaves, and higher amount of eggs was counted in the cv Obat? IAC 1669-20 and Catuaí Vermelho IAC 81, and lower oviposition frequency was observed in C. canephora cv. Guarini IAC 1598. C. congensis showed an oviposition frequency between C. arabica and C. canephora. Also, the results suggest that the frequency of oviposition is co-related with the plant resistance level, during larvae infection.  相似文献   
85.
We identified 22 polymorphisms in the adipocyte fatty-acid binding protein (FABP4) gene, a strong positional candidate gene for the FAT1 locus in porcine chromosome 4. The most informative polymorphism, an insertion/deletion in intron 1, together with a single nucleotide polymorphism in intron 3, was genotyped in a cross between Iberian and Landrace pigs. After performing QTL, single marker, and haplotype analyses, we showed that there were at least 2 quantitative trait genes in the FAT1 region and that the FABP4 polymorphism was tightly associated to fatness. A comparison of allelic frequencies in a panel of pig breeds suggested that the Del2634C polymorphism was under indirect selection. We also showed that FABP4 is tightly associated to fatness but not growth. Furthermore, a haplotype analysis suggests that there is genetic heterogeneity at the FAT1 locus within the Landrace breed.  相似文献   
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87.
Abstract. The paper highlights the advantages of modelling to simulate dynamic processes and to couple environmental data more closely with effects on crops. The CERES-Maize crop model and the DSSAT software package were selected for the work and the region of the Triângulo Mineiro in the state of Minas Gerais was selected as the study area. The results showed that there are differences in the potential production of the Latosols of the Triângulo Mineiro and this should be taken into account when extrapolating or transferring technology for other regions within the same cerrado ecosystem of central-west Brazil. It is essential to improve the number of points with weather data collection since, as demonstrated for Frutal, the climate of the Triângulo can determine differences in potential agricultural production as well as risk for production. The study showed that the use of crop models can improve land suitability evaluations, for land use planning, or establishing strategies for rural funding.  相似文献   
88.

BACKGROUND

Transgenic maize (Zea mays L.) event TC1507 (Herculex® I insect protection), expressing Cry1F δ‐endotoxin derived from Bacillus thuringiensis var. aizawai, was commercialized in 2003 in the Americas. Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) susceptibility to Cry1F was monitored annually across several regions in Argentina using diagnostic concentration bioassays. Reduced performance of TC1507 maize against S. frugiperda was reported in 2013. A resistant population was established in the laboratory and the dominance of Cry1F resistance was characterized.

RESULTS

During 2012–2015, high‐survivorship of several populations was observed in the resistance monitoring program. Reciprocal crosses of a Cry1F‐resistant population with a Cry1F‐susceptible population were evaluated to calculate effective dominance (DML) based on mortality levels observed at 100 µg/ml Cry1F. Two additional dominance levels (DLC and DEC) were calculated using lethal (LC50) or effective concentration (EC50) derived from concentration–response bioassays. Estimates indicated that Cry1F resistance in S. frugiperda in Argentina was either highly recessive (DML = 0.005) or incompletely recessive (DLC < 0.26 and DEC < 0.19).

CONCLUSION

This study is the first documented confirmation and characterization of S. frugiperda Cry1F field‐evolved resistance in Argentina. The resistance to Cry1F in S. frugiperda populations collected in Argentina, is autosomal and incompletely recessive similar to the resistance reported in Brazil. © 2017 The Authors. Pest Management Science published by John Wiley © Sons Ltd on behalf of Society of Chemical Industry.  相似文献   
89.
Tropical Animal Health and Production - We aimed to evaluate the chemical composition, production yield, and economic viability of Minas Frescal cheese produced with milk from buffaloes...  相似文献   
90.
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