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排序方式: 共有596条查询结果,搜索用时 15 毫秒
1.
Pierre Darcy Patrick Da Costa Henry Mellotte Jean-Michel Trichard Grald Djga-Mariadassou 《Catalysis Today》2007,119(1-4):252-256
To comply with the new regulations on particulate matter, car manufacturers more and more commonly use diesel particulate filters (DPF). The working of these systems needs to periodically burn soot that has been accumulated during the loading of the DPF. This paper describes the kinetics of the non-catalytic and catalytic oxidation of real diesel soot with oxygen. From these experiments, mechanisms for catalyzed and non-catalyzed soot oxidation have been proposed. 相似文献
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声波吹灰技术是提高锅炉换热效率,保证锅炉安全运行的重要手段之一.在不同压缩空气压力和流量条件下,试验对比研究了Φ80 mm×290 mm和Φ90 mm×300 mm 2种整体式耐高温高效声波吹灰器声场特性,获得了声波频率和声压值大小,确定了吹灰器声波作用的有效范围,分析了几何特征尺寸对声波的影响. 相似文献
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基于改进型Elman神经网络,建立了电站锅炉受热面污染在线监测软测量模型,为锅炉吹灰优化策略提供了理论依据。将软测量模型与传统吹灰程控系统融合所形成的智能吹灰程控系统采用模块化方法构建,集灰污在线监测、数据分析、信息管理和优化指导、控制功能一体化。该系统有助于加强吹灰管理,指导运行人员及时、合理吹灰、优化吹灰,达到提高机组安全性和经济性的目的。 相似文献
5.
Franco Cataldo 《Fullerenes, Nanotubes and Carbon Nanostructures》2005,13(3):239-257
A series of selected halomethanes were treated with the submerged carbon arc using graphite electrodes at 10A. CCl4 and CHCl3 produce abundant soot which is double in comparison to the soot produced by arcing CH2Cl2 and is one order of magnitude higher than the amount of soot produced by arcing hydrocarbons such as n-hexane or decalin and two orders of magnitudes higher in comparison to the amounts of soot produced by arcing alcohols. It was found a anticorrelation between the amount of polyynes present in the solution of the arced solvent and the amount of soot produced by arcing. In the case of CCl4 and CHCl3 no polyynes were detected by liquid chromatographic analysis (HPLC-DAD), while polyynes were detected in CH2Cl2 and are present in higher concentration in arced hydrocarbon solutions. The soot produced from halomethanes was analyzed by FT-IR spectroscopy in comparison to the soot produced by arcing hydrocarbons and alcohols. Furthermore, the soot from halomethanes was analyzed by HPLC-DAD after extraction with acetonitrile and found to contain a mixture of halogenated polycyclic aromatic hydrocarbons (PAHs). Also CHClBr and CH2I2 were arced between graphite electrodes. The former compound produces free bromine and soot; bromine causes halogenation of the polyynes. In the case of the latter compound, free iodine is released from the arc and the amount of soot produced is comparable to that obtained by arcing CH2Cl2. 相似文献
6.
Isabel C. Jaramillo Chethan K. Gaddam Randy L. Vander Wal Chung-Hsuan Huang Joseph D. Levinthal JoAnn S. Lighty 《Combustion and Flame》2014
The oxidation kinetics, under different pressures, of soot samples obtained from different liquid fuels and two standards (a commercial black carbon sample and a reference diesel soot) was studied. Soot samples were generated in a flat-flame, premixed burner under heavily-sooting conditions and captured on a water-cooled stabilization plate located above the burner surface. The collected soot was oxidized using a high-pressure thermogravimetric analyzer (HTGA). TGA operation was optimized to reduce mass transfer effects by adjusting the oxidizer flow rate and initial sample mass. Further corrections for mass transfer were accomplished by computing the effectiveness factors for intraparticle, interparticle, and external mass transfer. Two pressures were evaluated (1 and 10 atm) and O2 concentration was varied between 10 and 21%. 相似文献
7.
The details of the chemical and physical mechanisms of the soot formation process in combustion remain uncertain due to the highly complex nature of hydrocarbon flames, and only a few principles are firmly established mostly for atmospheric conditions. In spite of the fact that most combustion devices used for transportation operate at very high pressures (e.g., aircraft gas turbines up to 40 atm, diesel engines exceeding 100 atm), our understanding of soot formation at these pressures is not at a desirable level, and there is a fundamental lack of experimental data and complementary predictive models. The focus of this review is to assess the experimental results available from laminar co-flow diffusion flames burning at elevated pressures. First, a brief review of soot formation mechanisms in diffusion flames is presented. This is followed by an assessment of soot diagnostics techniques, both intrusive and non-intrusive, most commonly used in soot experiments including the laser induced incandescence. Then the experimental results of soot measurements done at elevated pressures in diffusion flames are reviewed and critically assessed. Soot studies in shock tubes and in premixed flames are not covered. Smoke point fuel mass flow rate is revisited, and shortcomings in recent measurements are pointed. The basic requirements for tractable and comparable measurements as a function of pressure are summarized. Most recent studies at high pressures with aliphatic gaseous fuels show that the soot yield displays a unified behaviour with reduced pressure. The maximum soot yield seems to reach a plateau asymptotically as the pressure exceeds the critical pressure of the fuel. Lack of experimental data on the sensitivity of soot morphology to pressure is emphasized. A short summary of efforts in the literature on the numerical simulation of soot formation in diffusion flames at high pressures is the last section of the paper. 相似文献
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汽车排放的氮氧化物(NOx)和碳烟颗粒物(PM)会对环境和人类健康造成严重的危害,但是现有的技术仅能对NOx或PM的排放实现单独净化。与其他尾气净化技术相比,柴油机颗粒物-氮氧化物减排系统(DPNR)兼具NOx和PM净化效果,成为下一代NOx和PM协同净化的首选催化系统。本文综述了DPNR催化反应机理以及系统中NOx和PM系统净化用的贵金属催化剂的研究进展;总结了Pt基催化剂在不同条件下同时消除NOx和PM的催化活性,系统地讨论了Ba、K、Mn等元素掺杂对Pt基催化剂的影响。同时归纳比较Ag基、Ru基与Pt基催化剂在PM氧化和NOx消除方面的区别,为研究开发同时消除NOx和PM的高效催化剂提供参考。 相似文献