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81.
The effect of pyrimethanil on the levels of cell wall degrading enzymes secreted by Botrytis cinerea Pers. was investigated in diseased plant tissues and in liquid B. cinerea cultures. Total proteinase activity isolated from infected carrot slices which were treated with 5.0 μM pyrimethanil was decreased by 76%, 3 d after inoculation. Polygalacturonase, cellulase, proteinase and laccase activities were all decreased in the medium of three day-old cultures grown in the presence of pyrimethanil. The pyrimethanil concentrations resulting in 50% reduction in total enzyme activities (IC50) were approximately 0.25 μM for polygalacturonase, cellulase and proteinase, and approximately 1.0 μM for laccase. No significant growth inhibition was observed at these pyrimethanil concentrations. Pyrimethanil did not inhibit the enzymes directly, nor did it inhibit the synthesis of cytosolic proteins. Therefore, it was proposed that the fungicide inhibits protein secretion at a post-translational stage in the secretory pathway. Large differences were found in the effects of pyrimethanil on the growth of B. cinerea in liquid cultures and on agar plates, depending on the composition of the medium. In liquid media containing cellulose and protein as carbon and nitrogen sources, growth inhibition occurred at 5.0 μM pyrimethanil, whilst no growth inhibition was observed with 50 μM pyrimethanil in malt extract. Similarly, growth occurred on potato/dextrose agar (PDA) at 0.5 μM pyrimethanil, but no growth was seen at this concentration on agars containing cellulose and protein. Thus it appears that pyrimethanil is most active in media where the fungus has to utilise extracellular enzymes to mobilise the nutrients it requires for growth. 相似文献
82.
Richard J. Hamilton 《Pest management science》1993,37(2):141-146
The abiogenic and biosynthetic origins of mineral and vegetable oils are contrasted and the importance of soybean, palm, rape seed and sunflower as the major source of fatty acids is highlighted. The cheaper oils derived from animal sources also provide fatty acids. The extraction and refining processes for vegetable oils are explained, the composition of typical vegetable oils is discussed and the importance of the glyceride structure to the physical properties of the oils is emphasised. Stability, volatility and viscosity of vegetable oils are considered. Production of fatty acids by fat-splitting methods and the formation of methyl esters by inter-esterification are outlined. Mineral oil compositions are detailed and their properties explained. 相似文献
83.
Jonathan H. Foreman D.V.M. Stephen M. Reed D.V.M. Norman W. Rantanen D.V.M. M.S. Richard M. DeBowes D.V.M. M.S. Pamela C. Wagner D.V.M. M.S. 《Journal of Equine Veterinary Science》1983,3(5):154-164
Since the normal absorption of CSF occurs in the cerebral veins and venous sinuses, any obstruction to the normal flow and absorption of CSF will result in accumulation of CSF central to the site of obstruction. Such accumulation within the cranium is defined as hydrocephalus.A foal was presented with an enlarged and an abnormally-shaped skull, but with normal behavior. The filly's condition deteriorated. Radiographs showed a domeshaped cranial vault with compression of the frontal sinus region. Massive hydrocephalus with little normal cerebral tissue left was diagnosed with ultrasound.Surgery was attempted to relieve the pressure. Eventually the foal was euthanized. Post-mortem confirmed the radiographic and ultrasound diagnosis. Since there was a lack of demonstrable obstruction, the authors suspected the foal had suffered from the Arnold-Chiari syndrome. 相似文献
84.
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87.
Mycotoxin photosensitivity 总被引:1,自引:0,他引:1
J L Richard 《Journal of the American Veterinary Medical Association》1973,163(11):1298-1299
88.
Richard T. Mayer C.W. Fisher J. Cocke A.C. Bridges J.K. Olson 《Pesticide biochemistry and physiology》1982,17(1):24-34
The fluorescent insect growth regulator 5[[[5-(dimethylamino)-1-naphthalenyl]amino]-1,3-benzodioxole (DNSAB) forms a metabolite complex with house-fly microsomal cytochrome P-450. Formation of the metabolite complex is dependent on the presence of NADPH and O2; NADH supports the reaction at a reduced rate. The presence of antibodies to house-fly cytochrome c (P-450) reductase in reaction mixtures inhibits the complex formation, indicating that the reductase is necessary for transfer of electrons from NADPH to cytochrome P-450 to complete the reaction. In the oxidized form, the metabolite complex has a single absorbance maximum at 431 nm, whereas the reduced form has two absorbance maxima at 426 (major) and 455 nm (minor). The pH of the media affects the extinction of the 426- and 455-nm Soret bands; increased pH decreases the extinction of the 426-nm band and increases the extinction of 455-nm band. Formation of the DNSAB metabolite-cytochrome P-450 complex decreases the amount of CO-reactive cytochrome P-450 by 24%. The metabolite complex is not dissociable by treatment with ferricyanide or by using centrifugation techniques. Dissociation is accomplished by addition of DNSAB to the oxidized metabolite complex. Kinetic analysis of the complex formation gives apparent Km and Vmax values at 2.55 ± 1.0 μM and 1.1 ± 0.4 × 10?2 ΔA min?1 nmol?1 cytochrome P-450, respectively. Addition of juvenile hormone [(E,E)-cis-methyl-10,11-epoxy-7-ethyl-3,11-dimethyl-2,6-tridecadienoate; JH] to the reaction medium competitively inhibits the formation of the metabolite complex giving an inhibition constant of 16 μM. DNSAB synergized the lethal effects of JH against Aedes aegypti larvae threefold; however, JH did not synergize DNSAB. These data suggest that DNSAB may acquire its hormonal qualities by complexing a species of cytochrome P-450 that metabolizes JH, thereby prolonging the in vivo lifetime of this hormone. 相似文献
89.
90.
Adin DB Hill RC Scott KC 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(5):724-726
Parenteral veterinary furosemide is a 50-mg/mL solution with a pH of 8.0-9.3. The purpose of this study was to determine whether a commonly used veterinary formulation of 50 mg/mL of furosemide solution could be diluted in vitro without precipitation. Furosemide 50 mg/mL was diluted to concentrations of 10 and 5 mg/mL with 5% dextrose in water (D5W), 0.9% saline, lactated Ringer solution (LRS), and sterile water. Acidic sterile water and basic sterile water solutions were made by the addition of hydrochloric acid and sodium hydroxide, respectively, for use as controls to assess the effect of pH extremes for each concentration. After furosemide dilution, the final pH of each sample was measured, and samples were grossly and microscopically examined for clarity and crystal formation immediately and 1, 3, 5, and 8 hours after dilution. Gross precipitation and microscopic crystals were immediately observed in the acidic controls. Solutions of 5 mg/mL in LRS and 0.9% saline became slightly cloudy immediately, but no crystals were observed microscopically for 8 hours. Solutions of 10 mg/mL in D5W, 0.9% saline, LRS, and sterile water and solutions of 5 mg/mL in D5W and sterile water and the basic control were grossly clear, and no microscopic crystals were observed for 8 hours. On the basis of the results obtained in this in vitro investigation, this veterinary formulation of furosemide 50 mg/mL can be diluted without precipitation to a concentration of 10 mg/mL with D5W, 0.9% saline, LRS, or sterile water and to 5 mg/mL with D5W or sterile water and held for 8 hours. 相似文献