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141.
Assessment of Genetic Variability in the Coding Sequence of Melatonin Receptor Gene (MTNR1A) in Tropical Arid Sheep Breeds of India 下载免费PDF全文
VK Saxena BK Jha AS Meena HK Narula D Kumar SMK Naqvi 《Reproduction in domestic animals》2015,50(3):517-521
Seasonal behaviour in sheep, which varies in tropical and temperate environmental conditions, is a matter of study, because it can provide a clue to address the problem of seasonality in sheep. Melatonin receptor is the membrane‐bound G‐coupled receptor, sensing the message of photoperiodic cues thorough melatonin. Restriction fragment length polymorphism (RFLP) studies were carried out to assess the variability of gene at G612A and C606T SNPs in MTNR1A gene, which have been studied to be markers for out‐of‐season breeding. Allelic frequency distribution corresponded to higher frequency of GG and CC genotype, in tropical arid sheep breed in comparison with temperate region sheep breed. PCR amplification of MTNR1A gene of 30 animals was performed and single nucleotide polymorphisms (SNPs) identification was carried out using Lasergene software. Seven SNPs/mutations were identified, but most of them were synonymous, except the one G706A, leading to substitution of valine by isoleucine. Polyphen‐2 analysis of G706A mutation revealed that it is a benign mutation. Two important SNPs C426T and G555A, which were identified in temperate sheep breeds, could not be traced in Magra and Marwari breeds of sheep. Thus, the Magra and Marwari breeds of tropical, arid region demonstrated the presence of both polymorphic SNPs markers G612A and C606T, associated with out‐of‐season breeding. GG and CC genotypes were having a higher prevalence in the studied population. 相似文献
142.
Ancient mantle in a modern arc: osmium isotopes in izu-bonin-mariana forearc peridotites 总被引:2,自引:0,他引:2
Mantle peridotites drilled from the Izu-Bonin-Mariana forearc have unradiogenic 187Os/188Os ratios (0.1193 to 0.1273), which give Proterozoic model ages of 820 to 1230 million years ago. If these peridotites are residues from magmatism during the initiation of subduction 40 to 48 million years ago, then the mantle that melted was much more depleted in incompatible elements than the source of mid-ocean ridge basalts (MORB). This result indicates that osmium isotopes record information about ancient melting events in the convecting upper mantle not recorded by incompatible lithophile isotope tracers. Subduction zones may be a graveyard for ancient depleted mantle material, and portions of the convecting upper mantle may be less radiogenic in osmium isotopes than previously recognized. 相似文献
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Potential magnitude of future vegetation change in eastern north america: comparisons with the past 总被引:2,自引:0,他引:2
Increases in atmospheric trace gas concentrations could warm the global average temperature 1.5 degrees to 4.5 degrees C by the end of the next century. Application of climate-pollen response surfaces to three climate model simulations of doubled preindustrial atmospheric CO(2) levels shows that the change in the equilibrium distribution of natural vegetation over eastern North America over the next 200 to 500 years could be larger than the overall change during the past 7,000 to 10,000 years and equivalent to the change that took place over the 1,000- to 3,000-year period of most rapid deglaciation. Some plant ranges and abundance maxima could shift as much as 500 to 1000 km during the next 200 to 500 years; such changes would have dramatic impacts on silvicultural and natural ecosystems. Although unprecedented vegetation change is likely if climate changes as predicted, forecasting the exact timing and patterns of change will be difficult. 相似文献
145.
Haustorial morphology of the cone-rust pathogen, C. conigenum, was investigated among naturally infected female strobili of three Guatemalan pines, P. maximinoi, P. pseudostrobus, and P. oocarpa. Among the three pine species, haustorial shapes and sizes were more variable in P. maximinoi and P. oocarpa than in P. pseudostrobus. The haustorial shapes and sizes were more variable in parenchyma cells of the cortex, xylem, and pith than in the cells in the phloem, xylem rays, and tracheids. The haustoria were also present in larger numbers in the parenchyma cells of the cortex, xylem, and pith than in phloem parenchyma cells and tracheids. In living cells, the tips of some haustoria were appressed to the host nuclei. 相似文献
146.
Miguel L. Villarreal Robert H. Webb Laura M. Norman Jennifer L. Psillas Abigail S. Rosenberg Shinji Carmichael Roy E. Petrakis Philip E. Sparks 《Land Degradation \u0026amp; Development》2016,27(4):1106-1121
Decades of intensive off‐road vehicle use for border security, immigration, smuggling, recreation, and military training along the USA–Mexico border have prompted concerns about long‐term human impacts on sensitive desert ecosystems. To help managers identify areas susceptible to soil erosion from anthropogenic activities, we developed a series of erosion potential models based on factors from the Universal Soil Loss Equation (USLE). To better express the vulnerability of soils to human disturbances, we refined two factors whose categorical and spatial representations limit the application of the USLE for non‐agricultural landscapes: the C‐factor (vegetation cover) and the P‐factor (support practice/management). A soil compaction index (P‐factor) was calculated as the difference in saturated hydrologic conductivity (Ks) between disturbed and undisturbed soils, which was then scaled up to maps of vehicle disturbances digitized from aerial photography. The C‐factor was improved using a satellite‐based vegetation index, which was better correlated with estimated ground cover (r2 = 0·77) than data derived from land cover (r2 = 0·06). We identified 9,780 km of unauthorized off‐road tracks in the 2,800‐km2 study area. Maps of these disturbances, when integrated with soil compaction data using the USLE, provided landscape‐scale information on areas vulnerable to erosion from both natural processes and human activities and are detailed enough for adaptive management and restoration planning. The models revealed erosion potential hotspots adjacent to the border and within areas managed as critical habitat for the threatened flat‐tailed horned lizard and endangered Sonoran pronghorn. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
147.
An adult dog with a persistent elevation in alkaline phosphatase enzyme activity was started on mitotane for suspected hyperadrenocorticism. One month later, the dog was presented for intermittent anorexia and acute icterus. The dog's liver enzyme activities and total bilirubin were markedly elevated, prothrombin time was prolonged, and blood urea nitrogen and glucose were low. Histopathology revealed marked, centrilobular, hepatocellular loss. After discontinuation of the mitotane, the dog recovered with supportive care and was normal 3 months later, which was consistent with mitotane-associated hepatic failure. 相似文献
148.
Webb C Bedwell C Guth A Avery P Dow S 《Veterinary immunology and immunopathology》2006,112(3-4):129-140
Oxidative stress and abnormal glutathione metabolism is thought to play an important role in various diseases of cats. However, current assays for the reduced form of glutathione (GSH) are time-consuming and semi-quantitative and do not allow assessment of GSH concentrations in individual cell populations. Therefore, we developed a flow cytometric assay for rapid determination of intracellular GSH concentrations in feline blood leukocytes. The assay was based on the ability of the non-fluorescent substrate monochlorobimane (mBCl) to form fluorescent adducts with GSH in a reaction catalyzed by the enzyme glutathione-S-transferase. Using flow cytometry, we found that mBCl was sensitive and specific for intracellular detection of the reduced form of GSH in feline leukocytes. Intracellular GSH concentrations were also stable for at least 24h in EDTA preserved whole blood samples stored at 4 degrees C. Neutrophils and monocytes from normal cats had significantly higher intracellular concentrations of GSH than T cells and B cells. The effects of FIV infection on intracellular GSH concentrations in cats were assessed using flow cytometry. We found that neutrophils from FIV-infected cats had significantly increased GSH concentrations, whereas intracellular GSH concentrations were significantly decreased in CD4(+) and CD8(+) lymphocytes from FIV-infected cats, compared to age-matched control animals. We conclude that a flow cytometric assay based on mBCl may be used to accurately and rapidly assess the effects of various disease states and treatments on GSH concentration in cat leukocytes and to help assess intracellular oxidative stress. 相似文献
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150.
Hart ML Suchodolski JS Steiner JM Webb CB 《Journal of Feline Medicine and Surgery》2012,14(4):240-245
This study was designed to test the hypothesis that in cats with chronic diarrhea the daily administration of a proprietary synbiotic (Proviable-DC) would result in an improvement in stool character, as assessed by the owner. Adult cats with chronic diarrhea were recruited for the study and screened for systemic diseases. Fecal flotation, wet mount, immunofluorescence assay (IFA) for Giardia and Cryptosporidium species, and Tritrichomonas species polymerase chain reactions (PCRs) were used to screen for intestinal parasitism. The synbiotic was administered for 21 days; otherwise, no changes were made to ongoing treatment(s) or diet. The severity of the diarrhea was assessed using a standardized fecal scoring system and the owner's subjective perception before, and after, supplementation. The mean fecal score for the 53 cats completing the study decreased from 6.0 to 4.4, representing a significantly (P <0.001) firmer stool character. Seventy-two percent of owners perceived an improvement in their cat's diarrhea following a 21-day course of synbiotic supplementation. 相似文献