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101.
腹下无隔道大偏距跨声速S弯进气道气动特性的实验研究(英文) 总被引:2,自引:1,他引:2
An investigation on the ventral diverterless high offset S-shaped inlet is carried out at Mach numbers from 0.600 to 1.534, angles of attack from -4° to 9.4°, and yaw angles from 0° to 8°. Results indicate: (1) a large region of low total pressure exists at the lower part of the inlet exit caused by the counter-rotating vortices in the S-shaped duct; (2) the performances of the inlet at Mach number 1.000 reach almost the highest, so the propulsion system could work efficiently in terms of aerodynamics; (3) the total pressure recovery increases slowly at first and then remains unvaried as the Mach number rises from 0.6 to 1.0, however, it does in an opposite manner in the conventional diverter-equipped S-shaped inlet; (4) the performances of the inlet are generally insensitive to angles of attack from -4° to 9.4° and yaw angles from 0° to 8° at Mach number 0.850, and angles of attack from -2° to 6° and yaw angles from 0° to 5° at Mach number 1.534. 相似文献
102.
民用发动机污染排放及低污染燃烧技术发展趋势 总被引:17,自引:15,他引:17
针对民用发动机污染排放的现状,介绍了低污染燃烧技术发展概况及趋势,国际民航组织(ICAO)颁布的《航空发动机的排放》标准,以及中国民用航空局(CAAC)对排气污染物的规定,分析了排气污染物的生成机理和主要影响因素以及改善措施.对6种先进低污染燃烧室(分级、变几何、催化、贫油预混预蒸发燃烧室(LPP)、富油燃烧/淬熄/贫油燃烧技术(RQL)以及双环预混旋流(TAPS)等燃烧室)的工作原理与特点、以及应用状况作了简要分析.其中分级燃烧技术构成了先进低污染燃烧室设计的技术基础,而LPP,RQL与TAPS燃烧室为三种很有发展前途的低污染燃烧室.此外,还介绍了贫油直接喷射、燃料电池以及主动燃烧控制等三种新型的低污染燃烧技术,虽然实现这些技术难度较大,但有广阔的应用前景. 相似文献
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105.
连续爆轰发动机的二维数值模拟研究 总被引:2,自引:3,他引:2
介绍了连续爆轰发动机(Continuous detonation engine,简称CDE)的物理模型及爆轰波传播的物理机理,并对CDE流场的波结构进行了分析.使用两步化学反应模型对简化的CDE模型做了二维数值模拟研究.计算了圆柱面展开二维平面的多个爆轰循环过程.模拟结果较好地匹配了相关CDE实验所获得的流场结构.数值计算结果使我们可以更加透彻地理解CDE各方面的参数,对于CDE的进一步研究具有一定的指导意义. 相似文献
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Li Guangchao Zhu Huiren Fan Huiming Department of Aeroengines Northwestern Polytechnical University Xi’an China 《中国航空学报》2008,21(5):385-392
Discharge coefficients of 3-in-1 hole of three inclination angles and three spacing between holes are presented which described the discharge behavior of a row of holes. The inlet and outlet of the 3-in-1 hole both have a 15° lateral expansion. The flow conditions considered are mainstream turbulence intensities and density ratios of secondary flow to mainstream. The momentum flux ratios varied in the range from 1 to 4. The comparison is made of the discharge coefficients of three shaped holes to find an optimal hole with low flow loss. The results show that the discharge coefficients of 3-in- 1 hole are highest in three shaped holes and therefore this article is focused on the measurements of discharge coefficients of 3-in-1 hole for various geometries and aerodynamic parameters. The measured results of 3-in-1 hole indicate that turbulence intensities, density ratios and momentum flux ratios have weak influence on discharge coefficients for inclination angle of 20°. The high turbulence intensity yields the small discharge coefficients for inclination angle of 45° and 90°. The increased both momentum flux ratios and density ratios lead to the increased discharge coefficients for inclination angle of 45° and 90°. The increased inclination angle causes the rapidly increased discharge coefficients. There is a weak dependence of discharge coefficients on hole pitches. 相似文献
109.
Foreign Object Damage to Fan Rotor Blades of Aeroengine Part Ⅱ: Numerical Simulation of Bird Impact 总被引:1,自引:0,他引:1
Guan Yupu Zhao Zhenhua Chen Wei Gao Deping 《中国航空学报》2008,21(4):328-334
Bird impact is one of the most dangerous threats to flight safety. The consequences of bird impact can be severe and, therefore, the aircraft components have to be certified for a proven level of bird impact resistance before being put into service. The fan rotor blades of aeroengine are the components being easily impacted by birds. It is necessary to ensure that the fan rotor blades should have adequate resistance against the bird impact, to reduce the flying accidents caused by bird impacts. Using the contacting-impacting algorithm, the numerical simulation is carded out to simulate bird impact. A three-blade computational model is set up for the fan rotor blade having shrouds. The transient response curves of the points corresponding to measured points in experiments, displacements and equivalent stresses on the blades are obtained during the simulation. From the comparison of the transient response curves obtained from numerical simulation with that obtained from experiments, it can be found that the variations in measured points and the corresponding points of simulation are basically the same. The deforming process, the maximum displacements and the maximum equivalent stresses on blades are analyzed. The numerical simulation verifies and complements the experiment results. 相似文献
110.
变攻角下孔隙射流对高负荷扩压叶栅气动性能的影响 总被引:1,自引:0,他引:1
本文对采用孔隙射流的某大折转角雎气机叶栅进行了实验研究.给出了不同攻角下叶栅流道内的静压分布、表面极限流线以及出口流场的气动参数,通过在不同叶高处开孔探讨了孔隙射流位置对大负荷扩压叶栅气动性能的影响。实验结果表明,孔隙位置对端壁静压的影响不大;开多孔方案对叶栅气动性能的影响要强于单孔方案:在设计攻角下,孔隙射流能够改善角区流动,同时降低叶片中部损失,单孔方案的最佳开孔位置位于25%相对叶高处,质量平均能量损失系数相对原形叶栅降低4.75%,开多孔方案巾能量损失相对原形叶栅最多降低5.52%:在负攻角下.孔隙射流导致叶栅性能下降,而在正攻角下,孔隙射流大幅提高叶栅性能,能量损失系数相对原形叶栅最多降低12.7%。 相似文献