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91.
The roles of tumor necrosis factor (TNF)-alpha and the facilitative glucose transporter (GLUT) 4 on the induction of insulin resistance in peripheral tissues of cancer patients was examined by quantitative competitive PCR on biopsies of abdominal rectal muscle from patients with gastrointestinal cancer. The degree of insulin resistance in these patients was measured by the euglycemic hyperinsulinemic glucose clamp using a high physiologic insulin concentration (100 microU/ml). Quantitative competitive PCR was carried out using DNA competitors constructed by deleting 20-30 bp between the two primer annealing sites. Decreased glucose uptake (M value) in peripheral tissues was accompanied by a significantly increased TNF-alpha mRNA in skeletal muscle (r=0.867, p=0.0025). GLUT4 mRNA, however, was positively correlated with M values (r=0.739, p=0.015). The amounts of mRNAs for TNF-alpha and GLUT4 in skeletal muscle were not correlated. Serum TNF-alpha concentrations remained below the limit of detection. These findings suggest that the insulin resistance in peripheral tissues of cancer patients is in part due to the induction TNF-alpha mRNA and the down regulation of GLUT4 mRNA in peripheral tissues.  相似文献   
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Finding a fast, reliable, and reproducible approach for an accurate analysis of complex lipid mixtures of emulsifiers is crucial for the food and beverages, pharmaceuticals, personal care products, cosmetics, and agrochemicals industries. In the current study, a comprehensive qualitative and quantitative nuclear magnetic resonance (NMR) spectroscopy analysis of a high monoester mixture of soybean oil (HMMS) was conducted using 1H, 13C, and 31P NMR of 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane (CTDP) derivatives. The HMMS was produced by enzymatic alcoholysis of soybean oil and 1.2-propanediol in a supercritical CO2 system. Compositional distribution analysis, quantified by aliphatic carbons with 13C NMR, showed that HMMS is composed of more unsaturated fatty acids, comprised of polyunsaturated fatty acids (PUFA) (60 ± 1.1%) and monounsaturated fatty acids (MUFA) (22 ± 0.8%), than saturated fatty acids (18 ± 0.9%). The 31P NMR quantification of HMMS demonstrated that, out of the total amount of monoacylglycerols (MAG), they are composed of 21 ± 2.9% of 2-MAG and 4 ± 0.3% of 1-MAG. Among the three techniques, 31P NMR spectroscopy proved to be a practical methodology with high reproducibility for the precise detection and quantification of partially esterified glycerols and free fatty acids in complex lipid mixtures.  相似文献   
94.
Experimental work aimed at understanding the role of dislocation loops in limiting phonon mediated thermal transport in ceramics is presented. Faulted dislocation loops, having diameters of a few nanometers, were introduced by irradiating a polycrystalline cerium dioxide sample with 1.6 MeV protons at 700°C. XRD analysis indicated that irradiated samples retained their crystalline structure and exhibit very little lattice expansion suggesting a low concentration of point defects. Further microstructure characterization using transmission electron microscopy revealed that interstitial type faulted dislocation loops were primarily created as expected for these irradiation conditions. Thermal conductivity of the damaged layer was measured using a modulated thermoreflectance approach. Analysis of the experimental data using the classical Klemens-Callaway approach reveals that the conductivity reduction is primarily due to dislocation loops, while point defects and voids play only a minor role. These results provide experimental confirmation that faulted loops offer a unique arrangement for displaced atoms that leads to an unusually large reduction of thermal conductivity.  相似文献   
95.
One of the most serious problems when doing program analyses is dealing with function calls. While function inlining is the traditional approach to this problem, it nonetheless suffers from the increase in analysis complexity due to the state space explosion. Craig interpolation has been successfully used in recent years in the context of bounded model checking to do function summarization which allows one to replace the complete function body with its succinct summary and, therefore, reduce the complexity, but unfortunately this technique can be applied only to a pair of unsatisfiable formulae. In this work-in-progress paper we present an approach to function summarization based on Craig interpolation that overcomes its limitation by using random model sampling. It captures interesting input/output relations, strengthening satisfiable formulae into unsatisfiable ones and thus allowing the use of Craig interpolation. Evaluation results show the applicability of this approach; in our future work we plan to do a more extensive evaluation on real-world examples.  相似文献   
96.
Wetting is a surface phenomenon that commonly occurs in nature and has an enormous influence on human life. Slippery liquid-infused porous surfaces have recently been developed to support the growing demand for anti-fouling coatings. While short-chain fluorinated compounds, commonly used to reduce the surface energy of substrates, are banned due to environmental toxicity, silane-based compounds are expensive and barely scalable. In this sense, silicone-based chemistry may match the gap as a real alternative. However, the grafting approaches demonstrated so far suffered from either slow binding kinetics or are applied under harsh conditions. Here, it is demonstrated that polydimethylsiloxanes graft to virtually any substrate when illuminated by UV light serving simultaneously as a reducing surface energy agent and infusing lubricant. This procedure is applied on metals, metal oxides, and ceramics of various surface morphologies. The proposed approach is simple, fast, scalable, environmentally friendly, and of low-cost, yet forms stable lubricant-infused slippery surfaces by a one-pot process. Due to the biocompatibility of silicone-based compounds, the process is examined on plain medically applicable substrates such as scalpel blades and glass lenses that display enhanced corrosion resistance, reduced friction through incision, and repel blood staining and bacterial adhesion without deteriorating their mechanical and optical characteristics.  相似文献   
97.
Hypoxia, which commonly accompanies tumor growth, depending on its strength may cause the enhancement of tumorigenicity of cancer cells or their death. One of the proteins targeted by hypoxia is glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and we demonstrated here that hypoxia mimicked by treating C6 rat glioblastoma cells with cobalt chloride caused an up-regulation of the enzyme expression, while further elevation of hypoxic stress caused the enzyme aggregation concomitantly with cell death. Reduction or elevation of GAPDH performed with the aid of specific shRNAs resulted in the augmentation of the tumorigenicity of C6 cells or their sensitization to hypoxic stress. Another hypoxia-regulated protein, Hsp70 chaperone, was shown to prevent the aggregation of oxidized GAPDH and to reduce hypoxia-mediated cell death. In order to release the enzyme molecules from the chaperone, we employed its inhibitor, derivative of colchicine. The compound was found to substantially increase aggregation of GAPDH and to sensitize C6 cells to hypoxia both in vitro and in animals bearing tumors with distinct levels of the enzyme expression. In conclusion, blocking the chaperonic activity of Hsp70 and its interaction with GAPDH may become a promising strategy to overcome tumor resistance to multiple environmental stresses and enhance existing therapeutic tools.  相似文献   
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99.
Conclusions Tips made of MgO can operate in argon at 2400°C for up to 5 h.Tips of ZrO2 are suitable for measuring temperatures up to 2400°C for several minutes and for longer periods up to 1900°C both in vacuum and in atmospheres of nitrogen and argon.Long tips should be fitted to graphite rods.  相似文献   
100.
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