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991.
992.
993.
Anahi S. Vieira Priscila S. Pinto Walter Lilenbaum 《Tropical animal health and production》2018,50(2):229-238
Leptospirosis is a bacterial systemic infection which affects domestic animals and wildlife, as well as humans. Many wild animals act as reservoirs of leptospires. Nevertheless, the real role of wildlife animals as source of infection to livestock and humans, as well as the most important reservoirs and leptospiral strains remains unclear. This systematic review assesses the available data about wildlife and their biomes in Latin America, concerning to leptospiral infection. In addition, we discuss the development of the research on leptospirosis in wildlife in this region. After the application of exclusion criteria, 79 papers were analyzed, comprising 186 species, 122 genus, 53 families, and 19 orders from four classes. Mammals were the most studied class, followed by Amphibian, Reptile, and Aves. The Icterohaemorrhagiae serogroup was predominant in most biomes and many orders. A small number of antigens detected the majority of seroreactive animals of each class, and a smaller panel may be used at microscopic agglutination test. Further studies must always consider edaphoclimatic conditions besides only host class or species, in order to obtain a broader understanding of the wild epidemiological cycle of leptospirosis in the region. In conclusion, direct and indirect evidences demonstrate that leptospirosis is largely widespread among wildlife in all biomes of Latin America. Moreover, more research on the role of wildlife on the epidemiology of leptospirosis and its impact on livestock and public health are required, particularly focusing on direct detection of the agent. 相似文献
994.
Quantitative trait loci for phytate in rice grain and their relationship with grain micronutrient content 总被引:6,自引:0,他引:6
James C. R. Stangoulis Bao-Lam Huynh Ross M. Welch Eun-Young Choi Robin D. Graham 《Euphytica》2007,154(3):289-294
Phytate (inositol-hexa-phosphate) has an important role in plants but it also may have anti-nutritional properties in animals
and humans. While there is debate within the plant breeding and nutrition communities regarding an optimum level in grain,
there appears to be little information at the molecular level for the genetics of this trait, and its association with important
trace elements, in particular, Fe and Zn. In this preliminary study, quantitative trait loci (QTL) for grain phytates, Zn
and Fe in glasshouse-grown rice lines from an IR64 × Azucena doubled haploid population were identified. Correlations between
phytate and essential nutrients were also studied. Transgressive segregation was found for most traits. Phytate and total
P concentrations had one QTL in common located on chromosome five with the (high concentration) allele contributed from Azucena.
There were significant positive correlations between phytate and inorganic phosphorus (P), total P, Fe, Zn, Cu and Mn concentrations
for both grain concentration and content. However, the QTLs of phytate were not located on the same chromosomal regions as
those found for Fe, Zn and Mn, suggesting that they were genetically different and thus using molecular markers in breeding
and selection would modify the phytate level without affecting grain micronutrient density. 相似文献
995.
Reducing overall water diversions for agriculture, while maintaining or increasing production to keep up with increasing world
population, has been and will continue to be a challenge. Yet there is not good agreement regarding the programs needed to
improve the productivity of agricultural water use, nor what increases are feasible. It is recognized that field irrigation
is inherently nonuniform. So also is the distribution of water to users and water delivery service nonuniform. Here, we suggest
that crop-scale irrigation uniformity can be examined at a project scale by understanding how field, farm and project irrigation
systems contribute to nonuniformity. We also discuss the interrelation between project scale uniformity and the relative irrigation
water supply, and their combined impact on project productivity. We provide an example which relates internal measures of
project performance (e.g., water distribution operations) and external measures of project performance (e.g., project-wise
water productivity). 相似文献
996.
Eddy covariance (EC) systems are being used to assess the accuracy of remote sensing methods in mapping surface sensible and
latent heat fluxes and evapotranspiration (ET) from local to regional scales, and in crop coefficient development. Therefore,
the objective was to evaluate the accuracy of EC systems in measuring sensible heat (H) and latent heat (LE) fluxes. For this
purpose, two EC systems were installed near large monolithic weighing lysimeters, on irrigated cotton fields in the Texas
High Plains, during the months of June and July 2008. Sensible and latent heat fluxes were underestimated with an average
error of about 30%. Most of the errors were from nocturnal measurements. Energy balance (EB) closure was 73.2–78.0% for daytime
fluxes. Thus, daylight fluxes were adjusted for lack of EB closure using the Bowen ratio/preservation of energy principle,
which improved the resulting EC heat flux agreement with lysimetric values. Further adjustments to EC-based ET included nighttime
ET (composite) incorporation, and the use of ‘heat flux source area’ (footprint) functions to compensate ET when the footprint
expanded beyond the crop field boundary. As a result, ET values remarkably matched lysimetric ET values, with a ‘mean bias
error ± root mean square error’ of −0.03 ± 0.5 mm day−1 (or −0.6 ± 10.2%). 相似文献
997.
E. Madejón A. I. Doronila P. Madejón A. J. M. Baker I. E. Woodrow 《Agroforestry Systems》2012,84(3):389-399
The effect of the addition of biosolids combined with a native arbuscular mycorrhizal inoculum on growth of a eucalypt (Eucalyptus cladocalyx), and on trace element stabilization of arsenical sulphidic gold mine tailings was tested. A glasshouse trial was established
using four substrates: tailings (T); tailings with a layer of topsoil (TS); tailings amended with 100 t ha−1 biosolids (LB), and tailings amended with 500 t ha−1 biosolids (HB). Half of the pots were inoculated with a mixture of Glomus sp. (WUM51–9227), Scutelospora aurigloba (WUM51–53) and Acaulospora laevis (WUM46) culture mix, and others were uninoculated controls. Two seeds per pot were sown. Leaf and stem weights, leaf area
and plant height were measured for each plant. Nutrients and trace element concentrations in leaves and stems were determined.
Addition of biosolids significantly increased mycorrhizal colonization (both ectomycorrhizal and arbuscular mycorrhizal)
in roots. Biosolids clearly increased the very early establishment and growth of the eucalypts. In general, mycorrhizal inoculum
increased plant biomass production and nutrient uptake. Trace element concentrations in trees of the biosolid-amended pots
were in general high, however, mycorrhizal inoculation could reduce the uptake of toxic elements by plants. 相似文献
998.
Siamak Rahmanpour David Backhouse Heather M. Nonhebel 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(4):429-433
The glucosinolate-myrosinase defence system, specific to Brassicales plants, produces toxic volatile compounds during mechanical
injury or pathogen attack. The reaction of this system to oxalic acid, known as a pathogenicity factor of Sclerotinia sclerotiorum, is not fully understood. The hydrolysis of glucosinolates was studied at varying conditions in the presence of oxalic acid
in the substrate. In a bioassay, colonies of the pathogen were exposed to volatiles from hydrated mustard powder used as a
myrosinase and glucosinolate source. The glucosinolate-myrosinase (GSL-M) system was activated in the presence of oxalic acid
at a concentration and pH similar to that expected in vivo. Volatile production was inhibited only when the pH fell to 3 or below. It is unlikely that oxalic acid plays a significant
role in disarming the GSL-M system during infection of Brassica hosts. 相似文献
999.
R. Pontzen H. Scheinpflug 《European journal of plant pathology / European Foundation for Plant Pathology》1989,95(1):151-160
With three plant pathogens,Botrytis cinerea, Venturia inaequalis and Puccinia graminis f. sp.tritici, the time course of sterol biosynthesis during spore germination was examined by labeling experiments along with the question whether this pathway could be inhibited by triazole fungicides. Conidia ofB. cinerea andV. inaequalis are able to synthesize sterols immediately after the beginning of the germination process when the germ tubes have not yet emerged. On the contrary uredospores ofP. graminis start sterol biosynthesis after 6 to 8 h germination time almost at the end of the germ tube phase, indicating that sterol reserves of the spores are likely to be used for the germ tube growth.The sterol C-14 demethylation appeared to be the rate limiting step within the sterol biosynthetic pathway: the half life of 24-methylenedihydrolanosterol was less than 1 h forB. cinerea. It was more than 1 h forV. inaequalis and 3 h forP. graminis. Independent of these differences in the time course of sterol biosynthesis and in the C-14 demethylation rate, the synthesis of sterols in germinating spores was strongly inhibited by triazole fungicides in all three pathogens examined. In contrast toP. graminis, this inhibition could be demonstrated withB. cinerea andV. inaequalis even in ungerminated conidia, indicating that the fungicides were rapidly taken up and reached their target within 1 or 2 h. These results are discussed along with the question whether spore germination can be used as a bioassay for the estimation of sensitivities of triazole fungicides. 相似文献
1000.
Associations of cyanobacterial communities in a typical chernozem contaminated with oil (0.05, 0.5, and 5% of the soil weight) were investigated. The high concentration of oil in the soil favored the development of other microorganisms (mostly, hydrocarbon oxidizers) on the surface and in the colonial mucus of cyanobacteria. 相似文献