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41.
Silver, gold, copper and platinum nanoparticles (NPs) were grown on surfaces in the form of patterns by the exposure of laser radiation onto droplets of metal ion solutions and the aid of a reducing agent. The generation of patterns from metallic NPs was achieved by combining induced growth of NPs and nanostructures by laser incidence directly on surfaces and optical image formation techniques for transferring the patterns. Near-UV (363.8 nm) and visible (532 nm) laser wavelengths were used for the laser-induced growth of NPs into microstructures on glass, quartz, stainless steel, silicon, and gold-on-silicon substrates. The sizes of the patterns formed were on the micrometer scale and the sizes of the transferred patterns were on the millimeter scale. The patterns formed were generated by optical transference of image and interference of laser beams. Ag and Au substrates were highly active in surface enhanced Raman spectroscopy (SERS). The enhanced Raman activity was measured for SERS probe molecules: 9H-purin-6-amine (adenine) and 1,2-bis (4-pyridyl)-ethane analytes on Ag and Au substrates, respectively. The enhancement factors obtained were 1.8×10(5) and 6.2×10(6), respectively.  相似文献   
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43.
The aim of this paper is the detailed analysis of different well-known thermodynamic efficiencies usually used to characterize hermetic compressors. Attention is focussed on the volumetric efficiency, the isentropic efficiency, and the combined mechanical–electrical efficiency. A procedure is presented to detach these efficiencies into their main components (physical sub-processes) to get deeper insight on the overall behavior.The volumetric efficiency is split into partial efficiencies related to pressure drop and heat transfer effects, supercharging effects, superdischarging effects, leakages, etc. The isentropic efficiency is detached using two different points of view: the work associated to the individual sub-processes (compression, discharge, expansion, suction), and the work associated to the underpressures, overpressures, and between the inlet and outlet mean compressor pressures. Finally, the combined mechanical–electrical efficiency is related to the heat transfer losses/gains, and to the exergy transfers and exergy destroyed.Even though some of the concepts introduced in the paper can be applied to different kinds of compressors, the discussion is specially focussed on hermetic reciprocating compressors. An advanced simulation model developed by the authors has been used to generate data to illustrate the possibilities of the detailed thermodynamic characterization proposed. The criteria developed are useful tools for comparison purposes, to characterize compressors, and to assist designers during the optimization process.  相似文献   
44.
Some Zn-Cr-O-based catalysts for the synthesis of methylpyrazine from ethylenediamine and propylene glycol were prepared through the sol-gel technique, from aqueous nitrates and polyacrylic acid. The oxide mixtures so obtained were analysed by several techniques, including scanning electron microscopy, electron probe microanalysis, X-ray diffraction, electron spin resonance (ESR), sorption-desorption of nitrogen, etc. The catalytic activity was tested by the pulse-reactor technique and with a temperature-programmed desorption-reaction apparatus. All the data were compared with those previously collected on similar catalysts prepared either by the wet-mixing procedure or by coprecipitation. It was found that the structure of the solid depends strongly on the method of preparation, besides the chemical composition. The selectivity to the desired product peaked for Zn/Cr=3 and the smaller the crystal size of the powder, the better the catalyst was found to perform. The ESR signal generated by the Cr3+ ions may constitute a useful tool for monitoring both the intimate structure and the catalytic behaviour of the material.  相似文献   
45.
Castleman's disease (angiofollicular hyperplasia of the lymphatic nodes) can exceptionally appear as a retroperitoneal mass of difficult differential diagnosis relative to other malignant retroperitoneal masses. Because of its rarity, one case report of a retroperitoneal mass with histologic study corresponding to Castleman's disease is contributed. A revision of the different histologic varieties of Castleman's disease, specific treatment and prognosis is included.  相似文献   
46.
The time course of the vinblastine(-sulfate; 10 mg/kg body weight, single injection)-induced enlargement and subsequent regression of the autolysosomal compartment was studied by electron microscopic morphometrical and cell biochemical methods in order to gain information concerning some key problems of this major route of intralysosomal degradation of the cell's endogenous macromolecules and structures. Detailed analysis of the dynamics of the total autophagic vacuole (AV) compartment and its different subcompartments (early, advanced, late, and fused AVs), as well as of changes of rough-surfaced endoplasmic reticulum (RER) showed: 1. Pancreatic acinar cells react to vinblastine biphasically, i.e. two expansion phases of the AV compartment, the first in the 0 to 90 min and the second in the 2 to 8 h post-injectional periods, were detected. 2. Fusions of AVs are not inhibited by vinblastine, at least during the second expansion phase when cytoplasmic volume fraction (CVF) of fused AVs steadily increased until the 12th h. Fusion of early, advanced and late AVs or composition of fused complex vacuoles (AVc) are somehow regulated, as the proportion of the three AV stages from the CVF of AVc, was maintained constant throughout the second expansion phase. 3. Stimulation of autophagosome formation and resulting substrate overload seems to be the primary mode of action by which vinblastine causes the enormous expansion of the autolysosomal compartment. 4. Degranulation of the rough-surfaced endoplasmic reticulum (RER) membranes occurs in a biphasic fashion, similarly to the volume and surface changes of the AV compartment, thus supporting our previous hypothesis, that labilization or change of RER may have a role in the formation of autophagosomes. 5. Vinblastine-induced autophagocytosis is a selective process, as mitochondria, Golgi elements and zymogen granules are very much underrepresented, whereas RER is more than twice overrepresented in the volume of early AVs, when compared to their volume fraction in the whole cytoplasm. 6. Immunogold electron microscopy revealed the presence of ubiquitinylated proteins in advanced and late, but not in early AVs.  相似文献   
47.
Double-skin envelopes are an attractive design option for high-end buildings. They allow architects to combine completely transparent external facades with an internal skin, which can also be transparent, or partially opaque. Between both skins there is an air channel that is used to collect or evacuate the solar radiation absorbed by the facade. This design may be a solution for reducing thermal overheating, which is common in completely transparent facades in Mediterranean climates. A numerical code was developed to analyze and predict the thermal behaviour of these facades. This code was applied to the analysis of the ‘standard’ geometry of a double-skin facade. A parametric study was carried out for typical Mediterranean climates to determine the influence of different variables, such as the position of blinds, the introduction of solid–liquid phase-change materials (PCM) and the use of low-ε glazing, etc. In order to characterize the thermal performance of the facades, two coefficients were defined that relate the indoor and enthalpic gains to the solar radiation. If they are designed carefully, ventilated facades will exhibit a significantly better passive behaviour than conventional glazed facades and also allow energy to be collected in the form of hot air to be used to reduce energy consumption in winter.  相似文献   
48.
The optimal and safer interleukin-2 (IL-2) dose for treatment of chronic hepatitis C virus (HCV) infection has been studied in 33 HCV-RNA positive patients with chronic hepatitis C. Patients were randomly allocated to receive 5 days per week during 12 weeks IL-2 doses of: 0.9 MIU (n = 10), 1.8 MIU (n = 10), or 3.6 MIU (n = 13). After 12 weeks, responder patients stopped treatment, whereas nonresponders received 12 additional weeks of IL-2 at the next higher dose: 1.8, 3.6, or 5.4 MIU. As a whole, after the first 12 weeks of IL-2 alanine aminotransferase (ALT) levels significantly decreased (P < .001) with respect to the baseline values (140 +/- 63 vs. 70 +/- 30 IU/L). At the end of treatment (24 weeks), the mean ALT level (80 +/- 50 IU/L) continued significantly lower (P < .001) than the baseline one, and 24% of patients normalized ALT levels; according to dosage, ALT normalization was: 0% for 0.9 MIU, 25% for 1.8 MIU, 5% for 3.6 MIU, and 18% for 5.4 MIU. HCV-RNA levels decreased during treatment, but in none of the patients became undetectable. All patients had a local reaction at the injection site with induration, erythema, and swelling, which was dose-related. The dose of 5.4 MIU was poorly tolerated and was reduced to 3.6 MIU in 4 of 11 patients. No changes in hematological parameters were observed. At the end of follow-up (6 months) four of eight responder patients continued with normal ALT. In conclusion, IL-2 treatment for chronic hepatitis C induced a biochemical response in 8 of 33 (24%) patients at the end of therapy while at the end of follow-up, 4 of 33 (8%) patients remained with normal ALT. The dose of 1.8 MIU is well tolerated and seems to be the most efficacious.  相似文献   
49.
The rate of capillary filtration in the lower limbs after hydroxyethylrutosides administered in various doses and by different routes was studied in patients with chronic venous insufficiency. Capillary filtration rate decreased immediately after intravenous and from 55 to 85 minutes after oral administration, depending on the dose. The slow-release tablets produced a definite falt in capillary filtration 240 minutes after administration.  相似文献   
50.
It can be seen that the technique of using properly selected filters to provide rigidly defined monochromatic bands with which to observe the fundus presents interesting and challenging information that is as yet mainly untapped. The applications quoted present only a small part of the areas that can be investigated. The technique is basically standard, but advances can still be made in optimizing filters. The question of what band width to use for a given application is by no means solved and presents a challenging avenue of inquiry. It should be pointed out that the use of color film with interference filters offers no advantage. The only dimension being recorded at each point in the film is reflectivity of the structure at the wavelength of the filter being used. Documenting the color of this wavelength by the use of color film is a fruitless exercise.  相似文献   
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