全文获取类型
收费全文 | 497篇 |
免费 | 63篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 47篇 |
综合类 | 33篇 |
化学工业 | 83篇 |
金属工艺 | 13篇 |
机械仪表 | 17篇 |
建筑科学 | 5篇 |
矿业工程 | 4篇 |
能源动力 | 302篇 |
轻工业 | 1篇 |
水利工程 | 1篇 |
石油天然气 | 7篇 |
武器工业 | 20篇 |
无线电 | 4篇 |
一般工业技术 | 17篇 |
冶金工业 | 13篇 |
自动化技术 | 4篇 |
出版年
2024年 | 3篇 |
2023年 | 18篇 |
2022年 | 17篇 |
2021年 | 17篇 |
2020年 | 22篇 |
2019年 | 13篇 |
2018年 | 16篇 |
2017年 | 11篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 24篇 |
2013年 | 28篇 |
2012年 | 27篇 |
2011年 | 37篇 |
2010年 | 27篇 |
2009年 | 35篇 |
2008年 | 26篇 |
2007年 | 26篇 |
2006年 | 26篇 |
2005年 | 20篇 |
2004年 | 25篇 |
2003年 | 21篇 |
2002年 | 24篇 |
2001年 | 18篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 1篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 3篇 |
排序方式: 共有571条查询结果,搜索用时 78 毫秒
1.
The devolatilization and volatile combustion of a single coal particle in spouted and spout-fluid beds have been studied. The results showed that the flame extinction time increases with the particle diameter, and decreases with the bed temperature. When the bed temperature and the air flow rate were fixed, the operation modes (spouted or spout-fluid bed) showed less effect on the mean flame extinction time. A mathematical model of the spouted bed mode for preignition and postignition periods has also been developed assuming the devolatilization rate to be controlled by heat transfer and multireaction pyrolysis kinetics based on volatile products. Ignition, heat transfer back from the volatile flame to the particle surface, variation in flame temperature, and the hydrodynamics of SB are taken into account. The model predictions, with some adjusting parameters, were in good agreement with experimental results. 相似文献
2.
为了延长微型涡喷发动机燃烧室的使用寿命,针对燃烧室壁面高温区进行全覆盖气膜冷却研究. 在KJ-66微型涡喷发动机试车实验的基础上,比较实际燃烧工况下,排布方式和燃烧室外环的扩张孔对气膜冷却效果及燃烧室整体性能的影响. 结果表明,在实际微型涡喷发动机模型中,顺排的平均综合冷却效率低于叉排,但对壁面的综合降温效果优于叉排. 随着扩张孔出口直径的增大,气膜冷却效果逐渐改善,但会影响燃烧室出口温度分布的均匀性. 由于燃烧室后排冷却孔的影响,二次流射入主流会发生偏转,提升了气膜的冷却效果. 整体而言,全覆盖气膜冷却在实际燃烧工况下对燃烧室壁面有着很好的冷却作用,扩张型气膜孔能够有效改善燃烧室外环的气膜冷却效果. 相似文献
3.
催化燃烧具有环保、高效、节能等诸多优点.综述了甲烷高温催化燃烧的研究现状,对甲烷燃烧催化剂材料的研究进展做了较详细的介绍,并阐述了甲烷高温催化燃烧反应器的研究进展. 相似文献
4.
5.
The modes of initiation and propagation of corrosion attack on a series of high-temperature alloys were studied in synthetic gas mixtures at 900°C. The gas mixtures were intended to simulate the oxygen and sulfur partial pressures experienced in reducing zones in a coal-fired fluidized-bed combustor and comprised mixtures of CO, CO2, and SO2. The alloys studied were candidates for in-bed heat exchanger tubing for an air-heater cycle operating at 843°C and 300–500 psig and so ranged from type 300-series stainless steels to nickel-base alloys. With the exception of two FeCrAlY alloys and types 304 and 347 stainless steels, it was found that sulfidation corrosion could be initiated on all the alloys within 0.25 hr; the rate of propagation of the corrosive attack depended on the flux of SO2 in the environment and on the nickel content of the alloys. The presence of iron in the alloys appeared to slow the initiation of sulfidation, by forming a continuous iron oxide layer. The effects of various alloying additions are discussed, and a schematic model for the initiation of sulfidation is proposed. 相似文献
6.
《Advanced Powder Technology》2023,34(3):103962
Based on the coal self-preheating combustion technology, this research proposed a novel internal fluidized bed combustor (IFBC) with an internal separator for stable preheating of fuel. In order to verify feasibility and operation stability of IFBC, cold experiment, electrical capacitance tomography (ECT) and computational particle fluid dynamic (CPFD) simulation were performed in a laboratory-scale IFBC. The effects of superficial air velocity (Ug) and return valve structure on the operation and gas-solid flow characteristics were investigated. The results revealed that the CPFD prediction agreed well with the experiment values. The pressure balance curve presented an “8″ shape distribution, and the particle volume fraction (PVF) showed ‘core-annular’ distribution features. With the increase of Ug, the PVF in the standpipe increased, and the discharge pattern of the return valve changed from continuous discharge to intermittent discharge, and the solid circulation flux showed a trend of increasing first and then decreasing. With the decrease of the outlet opening of return valve (Φ), the gas–solid flow behavior in standpipe experienced a transition from gas leakage, stabilizing material seal, and blocking state. For Ug = 2 m/s, Φ = 50 %, an effective solid seal in the return valve was established and IFBC has a stable circulation and operation. 相似文献
7.
J. L. Le H. C. Bai A. A. Mishunin A. V. Starov 《Combustion, Explosion, and Shock Waves》2003,39(3):292-299
Results of an experimental study of a full scramjet model operating on kerosene, which was performed in an IT-302M hotshot wind tunnel based at the Institute of Theoretical and Applied Mechanics of the Siberian Division of the Russian Academy of Sciences, and an experimental study of a model operating on hydrogen, which was performed in a hotshot wind tunnel with fire heating based at the China Aerodynamic Research and Development Center, are reported. The tests were performed for Mach numbers 5 and 6 for flow parameters close to in-flight conditions. An optimal system for kerosene injection under these conditions was determined, and the thrust characteristics of the engine model were examined. The possibility of controlling kerosene combustion in tests in the short-duration wind tunnel was analyzed, and special features of fuel ignition in a short combustor were considered. Intense combustion of kerosene was achieved with upstream injection of more than 3% of hydrogen, which allowed obtaining effective thrust. The distributions of static pressure and force characteristics of the model in the case of kerosene and hydrogen combustion were compared. 相似文献
8.
朱晓珊 《沈阳工程学院学报(自然科学版)》2012,8(2):134-136
建立燃气轮机燃烧室点火前的流体流动计算模型,利用计算流体力学软件,对3组不同速度流体的流动情况进行了模拟计算分析燃烧筒流道内的速度场,压力场,对比燃烧筒内在不同压力和速度下流场内流体的流动,模拟计算区域的流场,然后实际进行点火实验,验证模拟结果,发现流场分布最均匀最有利于点火. 相似文献
9.
应用燃烧试验台完成了某重型燃气轮机DLN(Dry-low NOx)燃烧室烧天然气时,燃料分配比例对燃烧特性影响的试验研究。试验结果表明:对于预混-扩散混合燃烧燃烧室,在总余气系数不变的情况下,增加预混燃料比例有利于燃烧室出口温度场均匀性提高,特别是周向温度分布系数(OTDF)对燃料分配比例尤为敏感;仅靠增加预混燃料不能降低NOx含量,预混均匀性是决定NOx的关键因素。这一结论为燃机的设计、改进提供了可靠参考和依据。 相似文献
10.
合成气燃气轮机燃烧室的试验研究 总被引:2,自引:0,他引:2
对某分管型燃气轮机燃烧室及其两个用于燃烧中热值合成气的改造方案在中压全尺寸试验台上进行了考核和实验研究。试验采用的等容积流率模化准则,即采用与真实燃烧室相同的尺寸、燃料、过量空气系数以及燃料和空气进口温度,而空气的总压和流量以及燃料的流量取为真实参数的1/6。试验结果表明2个改造方案的性能参数,包括燃烧效率、总压损失、出口温度分布、火焰筒壁面温度分布和火焰的稳定性(贫燃料熄火极限)都能够满足设计要求。此外,与原型燃烧室燃烧轻柴油的工况相比,2个改造方案在燃烧合成气时燃烧室主燃区的火焰筒壁面温度升高,而燃烧室的NOx排放大大降低,火焰的稳定性得到明显改善。因此保持火焰筒开孔规律不变,增大气体燃料喷射孔面积并增强旋流对燃烧室进行改造,使其能够高效洁净地燃烧中热值合成气,该方法是可行的。 相似文献