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51.
Resistance in Triticeae to fusarium head blight (FHB) is quantitatively inherited. Metabolomics as a tool was used to better understand the mechanisms of resistance and to identify potential FHB resistance biomarker metabolites in barley. Five FHB-resistant two-row barley genotypes (CIho 4196, Zhedar-1, Zhedar-2, Fredrickson, and Harbin-2r) and one FHB-susceptible genotype (CH 9520–30) were each inoculated with either pathogen-suspension or mock-solution. Disease severity, quantified as the proportion of spikelets diseased, varied among genotypes, being the greatest in CH 9520–30. Spikelets were sampled, metabolites extracted with aqueous methanol, and analyzed using an LC-ESI-LTQ-Orbitrap system. A pair wise, resistant vs. susceptible, t-test identified 1774 significant treatment peaks. Canonical discriminant analysis of peak abundance allowed the genotypes to be sorted into three clusters: (i) CH9520-30, (ii) Harbin-2r, (iii) the remaining four genotypes. The t-test was further used to identify resistance-related (RR) and pathogenesis-related (PR) metabolites. The pathogen-produced virulence factor deoxynivalenol (DON), and its detoxification product, DON-3-O-glucoside (D3G) were designated as resistance indicator (RI) metabolites. Metabolites (RR, PR, or RI) occurring in at least two resistant genotypes, showing a two-fold or greater abundance in resistant vs. susceptible lines, and also known to have plant defense functions were selected as potential FHB resistance biomarker metabolites. These included phenylalanine, p-coumaric acid, jasmonate, linolenic acid, total DON produced (TDP), and the proportion of DON converted to D3G (PDC). Total DON was the lowest in CIho 4196, while PDC was the highest in Zhedar-2. The application of RR, PR, and RI metabolites as potential biomarkers to enhance resistance is discussed.  相似文献   
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The catalytic activity of sulfated titania (ST) calcined at a variety of temperatures has been investigated for selective catalytic reduction (SCR) of NO by NH3. The NO removal activity of ST catalyst mainly depends on its sulfur content, indicating critical role of sulfur species on the surface of TiO2. The role of sulfur is mainly the formation of acid sites on the catalyst surface. The presence of both BrØnsted and Lewis acid sites on the surface of sulfated titania has been identified by IR study with the adsorption of NH3 and pyridine on ST. The reduction of the intensity of IR bands representing BrØsted acid sites is more pronounced than that revealing Lewis acid sites as the calcination temperature increases. It has been further clarified by IR study of ST500 catalyst evacuated at a variety of temperatures. The NO removal activity also decreases with the increase of the catalyst calcination temperature. It simply reveals that BrØnsted acid sites induced by sulfate on the catalyst surface are primarily responsible for the enhancement of catalytic activity of ST catalyst containing sulfur for NO reduction by NH3.  相似文献   
53.
SiC-coated film onto carbon fibers as a barrier of oxidation resistance and reaction between carbon fibers and metals was investigated. The chemical vapor deposition of silicon carbide onto carbon fibers was performed at various temperatures ranging from 700 to 1000°C using triisopropylsilane vapor carried by hydrogen gas. The strength of the SiC-coated carbon fibers was decreased due to deterioration of fibers and chemical attack of hydrogen on the surface of carbon fibers during the coating process. The oxidation and the thermal resistance of the SiC-coated carbon fibers compared to the uncoated carbon fibers were improved at temperature range of 600–800°C and 1000–1200°C, respectively. Morphological change by air oxidation at temperature range of 500–800‡C was also investigated for the SiC-coated and the uncoated carbon fibers, respectively. The SiC-coated film between carbon fiber and aluminum was sufficient as a barrier of reaction on carbon fiber reinforced aluminum at temperature of above 1000°C.  相似文献   
54.
High-pressure electroosmotic pumps (EOPs) operate on the principle that electroosmotic flow (EOF) can be generated through a packed-bed capillary by applying an electric field through it. In this paper, a novel packed-bed EOP design using nanosilica particles is described. The packed-bed capillary was fabricated using a capillary of 5 cm x 530 mum i.d. close packed with silica particles having an average particle size of 20-30 nm. The flow rates, pressures and pressure/flow rate (P-Q)characteristics, electric properties of the pump and the influence of phosphate buffer concentration on the pump were carefully studied. By increasing the pressure, decreasing the applied voltage, and the electric current, the thermodynamic efficiency was about 1%-2% for inorganic buffers and 3%-5% for organic solvents or their mixture without ions.  相似文献   
55.
The master-alloy ingots for casting bulk metallic glasses are routinely prepared by arc melting a mixture of pure elements. This paper addresses the difficulty in achieving complete and homogeneous melting of refractory component additions in Zr-based BMGs using the above procedure, and its influences on the microstructure and thermal behavior of alloys.  相似文献   
56.
In this study, nickel oxide was prepared through the calcination of extrusion dripped chitosan/nickel nitrate beads. The morphology and structural properties of the products were studied using various characterization techniques. Uniformly distributed nickel oxide was formed as observed from the studies of surface morphology where the processing parameters play a huge role on the resulting morphology. TEM results have shown that nickel oxide with crystallite sizes of 10–30 nm was obtained. The Fourier‐transform infrared spectra studies show an intense peak at 525 cm?1, which is attributed to the vibration of Ni–O bond. Furthermore, the XRD results show NiO diffraction peaks correspond to (111), (200), (220), (311), and (222) which indicates that a bunsenite structure with a face‐centered cubic phase was produced in this study. The usage of 500°C as the lower limit in this study is justified due to the complete removal of the templating material as seen in the thermalgravimetric analysis studies. Furthermore, it was obtained that the largest surface area of nickel oxide synthesized using this technique is 48.024 m2/g with pore sizes of 19.843 nm. The usage of chitosan as a green template for the synthesis of nanoparticles has shown promising results which allows a more economical and sustainable approach for the fabrication of nanomaterials.  相似文献   
57.
激光二极管是宽带调幅光纤发射系统的核心器件。光纤系统依赖于激光的稳定性,但未受调节控制的激光二极管特性却常因制造误差、温度和使用日久所造成的参数改变而变得不稳定。因此,光纤通信系统需要专用电路来控制重要的激光二极管参数,以确保它们稳定操作。虽然激光控制电路都  相似文献   
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The ultimate tensile strain of anodic films formed on 2024-T4 aluminum was evaluated as a function of pH in environments of 10−3M and 1·0M KNO3, using resistive and capactive techniques. In the resistive technique, ultimate tensile strain was defined as the strain at which a discontinuous increase in anodic current was observed; in the capacitive technique, film failure was marked by a discontinuity in the slope of the capacitance versus strain curve. The ultimate tensile strain was seen to be significantly greater at the zero-point-of charge of the oxide (pH 8) than at higher or lower pH; in the capacitive measurements the ultimate tensile strain had an average value of 0·97 at pH 8 and 0·87 for measurements made at pH values of 4, 7 and 9. Dielectric behavior of the anodic films was seen to be different only in degree from that of films formed on pure aluminum. Changes in capacitance associated only with exposure were measured and taken into account. Capacitance behavior with strain was modeled by two linear regions; the first was attributed to elastic deformation of the film and the second, after failure, to the growth of regions of metal covered only with a thin, spontaneously-formed oxide.  相似文献   
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