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31.
32.
Tunicamycin enhances the antiviral and anticellular activity of interferon   总被引:1,自引:0,他引:1  
The inhibitory effects of interferon on virus multiplication and cell growth are significantly enhanced by treatment with tunicamycin. Potentiation of antiviral activity was found only with enveloped viruses and not with nonbudding viruses. Changes in the plasma membrane of treated cells may account for this effect, since enveloped viruses bud from the cell surface as a terminal step.  相似文献   
33.
Thin zeolite films are attractive for a wide range of applications, including molecular sieve membranes, catalytic membrane reactors, permeation barriers, and low-dielectric-constant materials. Synthesis of thin zeolite films using high-aspect-ratio zeolite nanosheets is desirable because of the packing and processing advantages of the nanosheets over isotropic zeolite nanoparticles. Attempts to obtain a dispersed suspension of zeolite nanosheets via exfoliation of their lamellar precursors have been hampered because of their structure deterioration and morphological damage (fragmentation, curling, and aggregation). We demonstrated the synthesis and structure determination of highly crystalline nanosheets of zeolite frameworks MWW and MFI. The purity and morphological integrity of these nanosheets allow them to pack well on porous supports, facilitating the fabrication of molecular sieve membranes.  相似文献   
34.
In the present investigation we have succeeded in obtaining a high frequency of regeneration of plantlets via somatic embryogenesis from callus derived from immature inflorescence explains of Triticum aestivum var, ‘Sonalika’. The explants were cultured on MS medium supplemented with 2,4-D, casein hydrolysate and coconut milk. A large number of embryoids germinated, to form plantlets on the medium when 2, 4-D was omitted altogether or provided at low concentration. Plantlets were transferred to soil under natural environmental conditions and were shown to have the normal chromosome number of 2n = 6x = 42. Experiments with nineteen other varieties show that there is a marked effect of genotype both on initiation of callusing as well as on regeneration. So far ‘Sonahka’ has proved to be the most responsive among varieties tested by us. With callus of the variety ‘Sonalika.’, we also conducted an investigation on long-term retention of regenerative potential. During Song-term culture, for about 12 months, the morphogenic potential gradually diminished and was finally lost, but the regeneration potential could be restored by subculturing at very short intervals.  相似文献   
35.
Pseudomonas aeruginosa LES4, an isolate of tomato rhizosphere was found to be positive for several plant growth-promoting attributes like production of indole acetic acid, HCN and siderophore, solubilization of inorganic phosphate along with urease, chitinase and β-1-3-glucanase activity. In addition, it showed strong antagonistic effect against Macrophomina phaseolina and Fusarium oxysporum. P. aeruginosa LES4 caused halo cell formation and other morphological deformities in mycelia of M. phaseolina and F. oxysporum. Root colonization was studied with Tn5 induced streptomycin resistant transconjugants of spontaneous tetracycline-resistant LES4 (designated LES4tetra+strep+) after different durations. The strain was significantly rhizospheric competent, as 17.4% increase in its population was recorded in sesame rhizosphere. Seed bacterization with LES4 resulted in significant increase in vegetative growth parameters and yield of sesame over non-bacterized seeds. However, application of LES4 with half dose of fertilizers resulted in growth equivalent to full dose treatment, without compromising with the growth and yield of sesame. Moreover, the oil yield increased by 33.3%, while protein yield increased by 47.5% with treatment of half dose of fertilizer along with LES 4 bacterized seeds, as compared to full dose of fertilizers.  相似文献   
36.
Centrioles and basal bodies are essential for the formation of cilia, flagella, and centrosomes. They exhibit a characteristic ninefold symmetry imparted by a cartwheel thought to contain rings of SAS-6 proteins. We used cryoelectron tomography to investigate the architecture of the exceptionally long cartwheel of the flagellate Trichonympha. We found that the cartwheel is a stack of central rings that exhibit a vertical periodicity of 8.5 nanometers and is able to accommodate nine SAS-6 homodimers. The spokes that emanate from two such rings associate into a layer, with a vertical periodicity of 17 nanometers on the cartwheel margin. Thus, by using the power of biodiversity, we unveiled the architecture of the cartwheel at the root of the ninefold symmetry of centrioles and basal bodies.  相似文献   
37.
Foliar extracts of Annona squamosa (Family: Annonaceae) were screened for antimicrobial and insecticidal activity against the common microbial infestants of pulses and the stored grain pest pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae). Flavonoids isolated from aqueous extracts of A squamosa showed antimicrobial activity against all the common microbial contaminants of pulses and 80% insecticidal activity against C chinensis at a concentration of 0.07 mg ml-1. Various physico-chemical tests, chromatographic and spectroscopic studies with partially purified aqueous extract indicated the presence of flavonol type flavonoids. This may provide a useful beginning for the development of botanical pesticides for post-harvest safeguard of pulses.  相似文献   
38.
The present paper assesses the fertilization and hatching rates of an artificial fertilization series (n=1153) using fresh and cryopreserved sperm from 49 specimens of turbot Scophthalmus maximus (L.), carried out to confirm the results of a previous study, with the ultimate aim of transferring these cryo‐preservation techniques to commercial hatcheries. No significant differences were found between the fertilization rates of the two groups (fresh and cryopreserved sperm) when their respective fertility rates were >69.2%, which was the case in 75% of all fertilizations. Likewise, no significant differences in hatching rates were found. In order to use the cryopreserved sperm more efficiently, a key concern for commercial use of this technique, we also experimented with a lower sperm:diluent ratio (1:1) than used previously at our centre. We also compared the traditional 0.5‐mL straws with 2‐mL cryotubes able to contain a higher volume of sperm, finding no significant differences in the resulting fertilization and hatching rates. In conclusion, the use of cryopreservation for turbot sperm presents major advantages for broodstock management in commercial hatcheries.  相似文献   
39.
40.
Plants in their natural environment are constantly subjected to various abiotic and biotic stressors and, therefore, have developed several defense mechanisms to maintain fitness. Stress responses are intricate and require various physiological, biochemical, and cellular changes in plants. The reaction mechanisms in plants subjected to drought, salinity, or heat stress alone have been explained in numerous studies. However, the field conditions are significantly different from the controlled lab...  相似文献   
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