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851.
通过介绍喷雾降温蒸发冷却技术,指出国内首次将喷雾降温蒸发冷却技术大量应用在室外无建筑为依托的广场,实施了对室外空气进行等焓、降温、加湿处理;对比分析了西安和上海的典型气象年逐时参数,提出喷雾降温蒸发冷却技术在中等湿度地区、干燥地区会比高等湿度地区有较大应用前景和价值。 相似文献
852.
H. KaraagacM. Parlak 《Thin solid films》2011,519(7):2055-2061
AgGaS2 (AGS) thin films were deposited onto glass substrates by sequential thermal evaporation of AgGaS2 single crystalline powder and excess silver (Ag) interlayer. Systematic optimization to obtain single phase AgGaS2 thin films was carried out by changing the thickness of the excess silver layer. The structure and composition of as-grown and annealed films were studied by means of X-ray diffraction and energy dispersive X-ray analysis, respectively. The optical properties of AGS thin films determined by transmittance and reflection measurements showed that they had quite high absorption coefficient with the values around 104 (cm−1). The calculated band gap values were found to be between 2.30 and 2.75 eV depending on annealing temperature. The refractive index (n) and extinction coefficient (k) of the films were determined by the envelope method. Finally, photo-electrical measurements under different illumination intensities were carried out, and different sensitizing and recombination centers were defined. 相似文献
853.
Growth and optical applications of centimeter-long ZnO nanocombs 总被引:1,自引:0,他引:1
Ke Yu Qiuxiang Zhang Jin Wu Lijun Li Yu’e Xu Shaohua Huang Ziqiang Zhu 《Nano Research》2008,1(3):221-228
Ultralong ZnO nanocombs have been synthesized on silicon substrates with a high growth rate of ∼7 μm/s using a simple “thermal evaporation and condensation” method promoted by Cu catalysts. The lengths of the ZnO nanocombs
range from several millimeters to more than one centimeter and the diameters of the branches are about 300 nm. The growth
mechanism of the ultralong nanocombs and the catalytic behavior of the copper are discussed. The nanocombs were readily separated
and their applications as optical polarizer and grating were investigated. The results show that the ultralong ZnO nanocombs
can act as effective optical components in miniaturized integrated optics systems.
This article is published with open access at Springerlink.com 相似文献
854.
Mirac Alaf Mehmet Oguz Guler Deniz Gultekin Mehmet Uysal Ahmet Alp Hatem Akbulut 《Vacuum》2008,83(2):292-301
In this work, microstructural and physical properties were studied in the tin oxide films deposited by thermal evaporation of Sn films on stainless steel substrates followed by in situ D.C. plasma oxidation at 200 °C substrate temperature. The surface properties were studied by scanning electron microscopy, X-ray diffraction, atomic force microscopy and four-point probe electrical resistivity. The typical calculated grain size of the films deposited by thermal evaporation was between 28 nm and 66 nm and the texture structure was found to be dependent on the thermal deposition pressure. A cassiterite structure of SnO2 was produced by D.C. plasma oxidation with the main diffraction peaks of the (101), (200), (211), (310) and (221) planes at the 25% and 50% O2 partial pressure conditions. However, at 12.5% O2 partial pressure oxidation conditions, amorphous tin oxide structure and crystalline SnO phases were detected. Increasing thermal deposition pressure resulted in preferential texture formation at (211) and (310) planes. The surface structure investigation of the produced films by SEM and AFM studies showed large SnO2 islands with approximately 1.0 μm and 1.5 μm sized nodules, and they are called as grape-like structures. The grape-like grains possess nano grains, which are between 20 nm and 30 nm in diameter calculated by Scherer's formula. The grape-like grains were seen to be separated by large cavities and the size of these cavities and nano grains was seen to be larger when the O2 partial pressure is increased. The four-point probe resistivity of the films, grown at different oxidation temperatures, decreased with the increase in oxygen partial pressure. The values of resistivity for SnO2 phase were measured as low as 10−5 Ω-cm and observed to decrease with increasing thermal deposition pressure and oxygen partial pressure. 相似文献
855.
Gemma Gutiérrez Ángel Cambiella José M. Benito Carmen Pazos José Coca 《Journal of hazardous materials》2007
A simple batch vacuum evaporation process for the treatment of several oil-in-water (O/W) emulsions is reported. The experiments were carried out with waste emulsions from an industrial copper rolling process and with model emulsions prepared in the laboratory. No detailed information on the formulation of the industrial waste O/W emulsions was available. Several model emulsions were formulated using the same base oil (an 85–15% (w/w) mixture of a synthetic poly-α-olefin and a trimethylol propane trioleate ester, respectively) and one of the three following surfactants: Brij-76 (polyethylene glycol octadecyl ether, non-ionic), CTAB (hexadecyltrimethyl ammonium bromide, cationic), and Oleth-10 (glycolic acid ethoxylate oleyl ether, anionic). Experimental results show a strong influence of operating conditions, such as pressure or bath temperature, on the evaporation performance. As a general trend, the higher the values of these parameters, the higher the pollutant content in the obtained aqueous effluent. The presence of surfactants increase the evaporation rate, especially at low operating vacuum pressures, the solubility of oil molecules in water and the evaporation temperature of model O/W emulsions. Furthermore, COD reductions higher than 99.5% for the treated waste O/W emulsions were achieved. 相似文献
856.
857.
本文用一种新的分析方法闪蒸-气相色谱(FE—GC)来研究中药鱼腥草的挥发性组分,用质谱鉴定了其挥发性物质的化学组成,并和传统的水蒸气蒸馏法进行了对比。结果表明:该方法简单、快速、可靠,样品粉末可直接用于分析,不需要复杂费时的前处理过程,且样品需要量少。这对鱼腥草化学成分整体性研究和有效成分提取方法的开发具有非常重要的意义。 相似文献
858.
有色冶炼行业产生的高盐废水存在成分复杂、难以直接回用、处理难度大等难题。首先分类阐述了处理高盐废水的热蒸发法、电化学法和膜处理法,随后对上述技术的原理、技术特点、优缺点和应用情况进行了详细分析与总结。最后,对有色冶炼行业高盐废水处理技术发展趋势进行了展望。 相似文献
859.
The present work is carried out to study the evaporation of Na2O from CaO–Al2O3–SiO2–TiO2–MgO–Na2O slags with high basicity and high alumina in the temperature range of 1500–1560°C. The ratio of evaporation was determined by monitoring the Na2O content change of the slag melt under isothermal reduction conditions. The results show that the evaporation ratio increases with increasing the temperature. Higher basicity and increasing concentrations of Na2O, Al2O3 are also found to increase the evaporation ratio of Na2O, while MgO addition only slightly enhances the evaporation ratio. With TiO2 content increasing, the evaporation ratio first increases and then decreases. The evaporation rate of Na2O appears to be controlled by chemical reaction at the slag/gas interface in the beginning, followed by a mixed reaction-mass transfer regime, and finally a liquid-phase mass transport step. The apparent activation energy is 134.74?kJ?mol?1 for the chemical reaction regime and 268.53?kJ?mol?1 for the liquid-phase mass diffusion step. 相似文献
860.
Diamond-like carbon (DLC) thin films are extensively utilized in the semiconductor, electric and cutting machine industries owing to their high hardness, high elastic modulus, low friction coefficients and high chemical stability. DLC films are prepared by ion beam-assisted deposition (BAD), sputter deposition, plasma-enhanced chemical vapor deposition (PECVD), cathodic arc evaporation (CAE), and filter arc deposition (FAD). The major drawbacks of these methods are the degraded hardness associated with the low sp3/sp2 bonding ratio, the rough surface and poor adhesion caused by the presence of particles. In this study, a self-developed filter arc deposition (FAD) system was employed to prepare metal-containing DLC films with a low particle density. The relationships between the DLC film properties, such as film structure, surface morphology and mechanical behavior, with variation of substrate bias and target current, are examined. Experimental results demonstrate that FAD-DLC films have a lower ratio, suggesting that FAD-DLC films have a greater sp3 bonding than the CAE-DLC films. FAD-DLC films also exhibit a low friction coefficient of 0.14 and half of the number of surface particles as in the CAE-DLC films. Introducing a CrN interfacial layer between the substrate and the DLC films enables the magnetic field strength of the filter to be controlled to improve the adhesion and effectively eliminate the contaminating particles. Accordingly, the FAD system improves the tribological properties of the DLC films. 相似文献