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排序方式: 共有610条查询结果,搜索用时 15 毫秒
601.
Bursztyka J Debrauwer L Perdu E Jouanin I Jaeg JP Cravedi JP 《Journal of agricultural and food chemistry》2008,56(12):4832-4839
Vinclozolin is a dicarboxymide fungicide that presents antiandrogenic properties through its two hydrolysis products M1 and M2, which bind to the androgen receptor. Because of the lack of data on the biotransformation of vinclozolin, its metabolism was investigated in vitro in precision-cut rat liver slices and in vivo in male rat using [ (14)C]-vinclozolin. Incubations were performed using different concentrations of substrate, and the kinetics of formation of the major metabolites were studied. Three male Wistar rats were fed by gavage with [ (14)C]-VZ. Urine was collected for 24 h and analyzed by radio-HPLC for metabolic profiling. Metabolite identification was carried out on a LCQ ion trap mass spectrometer. In rat liver slices and in vivo, the major primary metabolite has been identified as 3',5'-dichloro-2,3,4-trihydroxy-2-methylbutyranilide (M5) and was mainly present as glucuronoconjugates. M5 is produced by dihydroxylation of the vinyl group of M2. Other metabolites have been identified as 3-(3,5-dichlorophenyl)-5-methyl-5-(1,2-dihydroxyethyl)-1,3-oxazolidine-2,4-dione (M4), a dihydroxylated metabolite of vinclozolin, which undergoes further conjugation to glucuronic acid, and 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3,4-dihydroxy-butanoic acid (M6), a dihydroxylated metabolite of M1. 相似文献
602.
Chen B Han A McClements DJ Decker EA 《Journal of agricultural and food chemistry》2010,58(22):11993-11999
The oxidation of edible oil yields both primary and secondary oxidation products (e.g., hydroperoxides, carbonyls, hydrocarbons, and epoxides), which produce undesirable sensory and biological effects. Consequently, the suppression of lipid oxidation in food matrices is of great importance. The rate and extent of lipid oxidation in many heterogeneous foods are strongly affected by the physicochemical characteristics of water-oil interfaces. This study examined the ability of dioleoylphosphatidylcholine (DOPC) and water to form association colloids within bulk oil, as well as their impact on lipid oxidation kinetics. Attenuation was used to show the DOPC and water concentrations at which association colloids existed without altering the optical properties of the oil. Interfacial tension and fluorescence spectrometry showed the critical micelle concentration (CMC) of DOPC in stripped soybean oil was around 650 μM at room temperature. Small-angle X-ray scattering (SAXS) and fluorescence probes showed that water had a very strong impact on the properties of the association colloids formed by DOPC. Measurement of primary and secondary lipid oxidation products revealed that the association colloids formed by DOPC had a pro-oxidant effect. The characterization of association colloids could provide a better understanding of the mechanisms of lipid oxidation in bulk oils and provide insights into new antioxidant technologies. 相似文献
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Oliver Fried Ingolf Kühn Julian Schrader Van Sinh Nguyen Erwin Bergmeier 《Paddy and Water Environment》2018,16(2):359-378
Which plant species can be found on rice field bunds and what are the prevailing life forms? Which plant communities occur and what are the main environmental drivers and phytogeographic patterns shaping these communities? How do species diversity and composition differ between bunds and paddies? To answer these questions, 133 vegetation relevés using the Braun-Blanquet method were collected in lowlands and uplands of Vietnam and the Philippines between 2012 and 2015. Soil samples were collected and farmers were interviewed. Properties of soil, climate, and geography were assessed, further structural parameters, landscape heterogeneity, seasonality, management and intensity of cultivation. Hierarchical UPGMA cluster analysis and NMDS ordinations were performed to visualize variation in plant community composition and the determinants. We found 302 vascular plant species, of which 94 species are red listed by the IUCN (under category “Least concern”). Therophytes and helophytes are the prevailing life forms. Six clusters of plant communities were classified, and temperature, soil acidity, land use intensity and nutrient availability were identified (according to relevance) as explanatory variables. Bunds revealed higher species richness than paddies and bunds in mountain areas were more species-rich than those in the lowlands. We conclude that the composition of bund communities provides valuable information on environmental and biogeographical conditions of the local rice landscapes, and that it is probably the best applicable and most reliable indicator of management intensity. 相似文献
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Edgar VZQUEZ-NEZ Julian M. PEA-CASTRO Fabin FERNNDEZ-LUQUEO Eduardo CEJUDO Maria G. de la ROSA-ALVAREZ Maria C. GARCA-CASTAEDA 《土壤圈》2018,28(5):697-712
In recent years, there has been an increasing interest in finding sustainable strategies for the efficient removal of contaminants from soils. The objective of this review is to examine the biochemical principles of specific genetic modifications in plants, their applications in the field for specific contaminants as phytotechnologies, and their international regulation. In addition, the review presents some biological aspects of rhizosphere-related phenomena, the interactions of organic and inorganic pollutants with plants, and the performance of the phytotechnologies across the continents. During the last few decades, at least eight genera of genetically modified plants (GMPs) have been tested and used for soil remediation with outstanding results. Arabidopsis, Nicotiana, and Oryza are the plant genera most widely studied. Specific plant genes such as metal transporters, chelators, metallothioneins, phytochelatins, and oxygenases have been transferred to plants to improve the elimination of contaminants in soil. We discuss some important aspects of gene manipulation and its application for removal of diverse contaminants. A key challenge faced by phytotechnologies is the final disposal of the generated biomass, from a safety aspect. We argue that the commercial success of phytotechnologies depends on the generation of valuable biomass on contaminated land and its use for bioenergy generation. The use of such technologies would promote a broader understanding of the importance of plants, especially GMPs, in the environment and their contribution to environmental sustainability. 相似文献
609.
Betanodavirus is the causative agent of the viral nervous necrosis (VNN) or viral encephalopathy and retinopathy disease in marine fish. This disease is responsible for most of the mass mortalities that occurred in marine fish hatcheries in Malaysia. The genome of this virus consists of two positive-sense RNA molecules which are the RNA1 and RNA2. The RNA1 molecule contains the RdRp gene which encodes for the RNA-dependent RNA polymerase and the RNA2 molecule contains the Cp gene which encodes for the viral coat protein. In this study, total RNAs were extracted from 32 fish specimens representing the four most cultured marine fish species in Malaysia. The fish specimens were collected from different hatcheries and aquaculture farms in Malaysia. The RNA1 was successfully amplified using three pairs of overlapping PCR primers whereas the RNA2 was amplified using a pair of primers. The nucleotide analysis of RdRp gene revealed that the Betanodavirus in Malaysia were 94.5-99.7% similar to the RGNNV genotype, 79.8-82.1% similar to SJNNV genotype, 81.5-82.4% similar to BFNNV genotype and 79.8-80.7% similar to TPNNV genotype. However, they showed lower similarities to FHV (9.4-14.2%) and BBV (7.2-15.7%), respectively. Similarly, the Cp gene revealed that the viruses showed high nucleotide similarity to RGNNV (95.9-99.8%), SJNNV (72.2-77.4%), BFNNV (80.9-83.5%), TPNNV (77.2-78.1%) and TNV (75.1-76.5%). However, as in the RdRp gene, the coat protein gene was highly dissimilar to FHV (3.0%) and BBV (2.6-4.1%), respectively. Based on the genome analysis, the Betanodavirus infecting cultured marine fish species in Malaysia belong to the RGNNV genotype. However, the phylogenetic analysis of the genes revealed that the viruses can be further divided into nine sub-groups. This has been expected since various marine fish species of different origins are cultured in Malaysia. 相似文献
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