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181.
182.
This study explores the pharmacokinetics of 22-S-hydroxycholesterol (22SHC) in vivo in rats. We also carried out a metabolic study to explore whether the beneficial effects observed of 22SHC on glucose and lipid metabolism in vitro could be seen in vivo in rats. In the pharmacokinetic study, rats were given 50 mg/kg of [3H]22-S-hydroxycholesterol before absorption, distribution and excretion were monitored. In the metabolic study, the effect of 22SHC (30 mg/kg/day for 3 weeks) in rats on body weight gain [chow and high-fat diet (HFD)], serum lipids triacylglycerol (TAG) content and gene expression in liver and skeletal muscle were examined. Results showed that 22SHC was well absorbed after oral administration and distributed to most organs and mainly excreted in feces. Rats receiving 22SHC gained less body weight than their controls regardless whether the animals received chow diet or HFD. Moreover, we observed that animals receiving HFD had elevated levels of serum TAG while this was not observed for animals on HFD supplemented with 22SHC. The amount of TAG in liver was reduced after 22SHC treatment in animals receiving either chow diet or HFD. Gene expression analysis revealed that two genes (carnitine palmitoyltransferase 2 and uncoupling protein 3) involved in fatty acid oxidation and energy dissipation were increased in liver. Ucp3 expression (both protein and mRNA level) was increased in skeletal muscle, but insulin-stimulated glucose uptake and TAG content were unchanged. In conclusion, 22SHC seems to be an interesting model substance in the search of treatments for disorders involving aberrations in lipid metabolism.  相似文献   
183.
Engineering levels of porosity in hierarchical zeolites is a vibrant area of research with remarkable application potential. To gain practical relevance, the superior properties observed for the as‐synthesized powders have to be preserved when they are shaped into suitable technical geometries. Herein, mechanically stable millimeter‐sized bodies are prepared by granulation of mesoporous ZSM‐5 zeolite powders using an attapulgite clay binder. Alkaline treatment of conventional zeolite granules is demonstrated to be unsuitable for this purpose. Multiple techniques are applied to characterize mesoporous zeolite granules with respect to their conventional zeolite counterparts, thus establishing the impact of binder inclusion and granulation on their respective properties. The intrinsic structure and acidity of the zeolite are retained post‐structuring. Gas adsorption and mercury porosimetry confirm the presence of interconnected micro‐, meso‐, and macropores. A wide range of imaging techniques permits visualization of the particle properties, phase distribution, and consequent origins of the distinct levels of porosity within the zeolite granules. The superior adsorption properties of the hierarchical ZSM‐5 zeolite granules are demonstrated using cyclohexane, toluene, and isopropyl alcohol as probe molecules.  相似文献   
184.
185.
Increasing energy consumption, shortages of fossil fuels, and concerns about the environmental impact of energy use, especially emissions of carbon dioxide, give fresh impetus to the development of renewable energy sources. With the advent of renewable energy, it is now indispensable that efficient energy storage systems have to be developed. One of the most promising storage systems to be employed in stationary energy storage applications are lithium-based batteries (LIB), mainly due to their high energy density, high power, and nearly 100 % efficiency. Within the scope of this paper, we carry out a patent search using the patent database PatBase® to assess the development status of LIB technology. The analysis of the generated patent sample reveals disproportionately high growth rates in LIB patent applications over the last years compared to other selected energy-related technologies. Breaking down patent application growth by the different components of LIB shows the principal drivers of growth. The purpose of this paper is to provide current research trends and prospects for the main LIB materials and designs.  相似文献   
186.
The effect of thermal treatment on the catalyst structure and the CO oxidation performance of a Au/TiO2 catalyst supported on a carbon composite material has been studied. X-ray absorption spectroscopy shows that the carbon composite stabilises the TiO2 and prevent agglomeration of the particles. The activity measurements show that both Au and TiO2 need to be present in order to obtain catalytic activity. The catalytic performance was found to be strongly affected by thermal treatments of the active phase prior to the reaction. The thermal treatments have an effect on the ordering of the TiO2 structure, and on the CO oxidation activity. Heat treatment after Au deposition has a positive effect on the CO oxidation performance. This is attributed to the introduction of a stronger interaction between the oxide and Au which improves the catalytic activity. This also indicates that the TiO2 support and the Au–TiO2 interface play important roles in the CO oxidation reaction.  相似文献   
187.
The light-induced degradation of lignin was studied using spruce MWL impregnated on handsheets prepared from cotton linters. The sheets were irradiated with simulated sunlight and the lignin was extracted. Solutions of untreated and irradiated lignin were studied by 1H and 13C NMR spectroscopy. The results showed that α- and β- ether and α-β bond cleavage were the main reactions. The main degradation products were vanillin and vanillic acid. The amount of terminal groups containing aromatic aldehyde and carboxyl groups also incre- ased on irradiation. The existing α- C=O groups were transformed mainly to carboxyl groups. However, the results indicate that new α- C=O groups were generated on irradiation. The methoxyl content decreased and some degradation of aromatic rings took place. However, no formation of quinoid structures was observed. Degradation of phenylcoumaran units was evident, α- Ether cleavage in phenylcoumarans could possibly lead to formation of stilbenes and stilbene derived chromophores.  相似文献   
188.
Calibration mixtures containing Ni0 and V4+ in the range from 500 to 4000 ppm have been prepared using various supports (silica, alumina, titania and ultrastable Y zeolite (USY)) with different particle sizes. ESR measurements revealed a linear relation between the impregnated metal amounts and the registered ESR signal integrals and/or intensities, suitable for the determination of the NiO (reduced to Ni0) and V4+ contents in FCC catalysts, respectively. The amount of NiO in a FCC equilibrium catalyst was determined to about 1300 ppm of a total of 2500 ppm Ni compound present in this sample, whereas the amount of V4+ was estimated to about 1800 ppm of a total of 2800 ppm vanadium species. Hence, this catalyst contains about 1000 ppm V5+. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
189.
The evolution of floral scent as a plant reproductive signal is assumed to be driven by pollinator behavior, with little attention paid to other potential selective forces such as herbivores. I tested 10 out of the 13 compounds emitted by dioecious Cirsium arvense, Canada thistle, including 2-phenylethanol, methyl salicylate, p-anisaldehyde, benzaldehyde, benzyl alcohol, phenylacetaldehyde, linalool, furanoid linalool oxides (E and Z), and dimethyl salicylate. Single compounds (and one isomer) set out in scent-baited water-bowl traps trapped over 10 species of pollinators and 16 species of floral herbivores. The two dominant components of the fragrance blend of C. arvense, benzaldehyde and phenylacetaldehyde, trapped both pollinators and florivores. Other compounds attracted either pollinators or florivores. Florivores of C. arvense appear to use floral scent compounds as kairomones; by advertising to pollinators, C. arvense also attracts its own enemies.  相似文献   
190.
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