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491.
国家社会经济发展的国际比较与评价 总被引:1,自引:0,他引:1
提出了正确评价中国社会的发展和进步是很重要的,简要介绍了国际组织,学者进行国际比较所采和的几种主要方法,着重介绍了用社会进步指数方法来确定1980年、1986年中国在亚洲的地位,社会进步指数包括七个方面的19年指标,用非加权和加权两种方法分别计算各国的社会进步指数,在计算加权的社会进步指数中采用了主分量分析方法来确定权数,该方法避免了人们的主观因素,提高了计算的准确度,非加权方法的计算结果表明,中 相似文献
492.
陈治怀 《中国民航学院学报》1994,12(1):15-22
本文应用SLAM—Ⅱ计算机模拟语言编制了Cessna—152飞机的进近着陆程序。SLAM—Ⅱ模拟语言具有数值积分功能,使连续过程的程序编写大为简便。用该程序计算分析了Cessna—152进近着陆过程中飞机各种运动参数对飞行员操纵的响应。 相似文献
493.
舒忠正 《南京航空航天大学学报》1986,(3)
本文叙述了在IBM-PC/XT个人计算机上,使用LISP语言研制的人机对奕一字棋程序中,如何成功地运用了启发式搜索法来设计该智能程序。並说明了该程序的设计思想,流程图及其运行情况。 相似文献
494.
将结构元件的弹性模量、泊松比、几何尺寸定义为随机场,并将随机场离散成随机变量,将抗拉强度定义为随机变量,采用Monte Carlo随机有限元法(MCSFEM),给出了元件危险点应力的随机分布。由危险点应力分布、材料的p-S-N曲线和Miner理论给出了概率名义应力法,计算常幅载荷下元件的寿命分布,并利用剩余寿命模型计算元件的可靠度。给出了两个算例,结果表明:计算结果与试验结果吻合良好。 相似文献
495.
A learning-based approach for solving wall shear stresses from Shear-Sensitive Liquid Crystal Coating(SSLCC) color images is presented in this paper. The approach is able to learn and establish the mapping relationship between the SSLCC color-change responses in different observation directions and the shear stress vectors, and then uses the mapping relationship to solve wall shear stress vectors from SSLCC color images. Experimental results show that the proposed approach can solve wall shear s... 相似文献
496.
《中国航空学报》2022,35(8):143-157
The damage effect assessment of anti-ship missiles combines system science and weapon science, which can provide reference for the assessment of battlefield damage situation. In order to solve the difficulty of heterogeneous data aggregation and the difficulty in constructing the mapping between factors and damage effect, this paper analyzes the specific damage process of the anti-ship missile to the ship, and proposes a synthetic Evidential Reasoning (ER) – Adaptive Neural Fuzzy Inference System (ANFIS) to assess the damage effect. To solve the problem of fuzziness and uncertainty of criteria in the assessment process, the belief structure model is used to transform qualitative and quantitative information into a unified mathematical structure, and ER algorithm is used to fuse the information of lower-level criteria. In order to solve the problem of fuzziness and uncertainty of the information contained in the first-level variables, and the strong non-linear characteristics of the mapping between first-level variables and damage effect, the ANFIS with self-adaptation and self-learning is constructed. The map between the three first-level variables and damage effect is established, and the interaction process of the various factors in the damage effect assessment are clear. Sensitivity analysis shows that assessment model has good stability. The result analysis and comparative analysis show that the process proposed in this paper can effectively assess the damage effect of anti-ship missiles, and all criteria data are objective and comparable. 相似文献
497.
The interaction between an elastic structure and electrodynamic shakers commonly exists in Ground Flutter Simulation Tests(GFST) with multi-point excitations, causing a considerable discrepancy between the practical excitation forces and desired ones. To investigate the excitation force characteristics on a cantilever beam excited by a voltage-sourced electrodynamic shaker,the coupled shaker-beam system is modeled to derive the excitation force formula using Hamilton’s principle and Galerkin’s a... 相似文献
498.
499.
《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2023,71(3):1769-1783
Lunar final approach navigation is critical for pin-point lunar landing in future missions. This study investigates the use of lunar gravity gradient measurements for autonomous navigation of a lunar probe during the final approach phase. As the spacecraft approaches the Moon, the strength of gravity gradient signals improves. A spaceborne gravity gradiometer can precisely measure local gravity gradients, and the latest lunar gravity model GL1500E is used to provide reference values. The employed truncation degree and order of the gravity model are increased stepwise considering the decreasing altitude of the spacecraft in order to reach a compromise between computational costs and model accuracy. An iterative Kalman filter is developed for coupled orbit and attitude estimation using gravity gradient measurements and attitude quaternions obtained from star sensors. A simulated spacecraft with a gradiometer noise level of 0.01 E is considered. Simulation results show that the spacecraft’s position converges rapidly and achieves an accuracy of less than 100 m at the last epoch. 相似文献
500.
地面模型是根据IAEA174号报告研建的用于校准便携式γ能谱仪、γ辐射仪的计量标准装置,最初主要用于地质勘查。2016年至2018年,新研建了钾含量30 %(YK3)和铀含量1 %(YU4)的两个模型,并确定了模型量值。远离模型表面中心位置的剂量率较低,随着中心点的接近,剂量率逐渐上升,YK3和YU4的剂量率坪区分别为模型中心点及周围半径约40 cm和50 cm范围内,在坪区内剂量率变化均不大于0.6 %;在参考点3.0 cm上的剂量率分别为320.8 nGy·h-1和4.3×104 nGy·h-1;超过3.0 cm时,剂量率随高度呈非线性变化;根据不同高度上的理论计算和实测结果比对,在40 cm高度实测范围以内,YK3实测结果与理论计算结果相对偏差在3 %范围以内,120 cm高度实测范围内,YU4实测结果与理论计算结果相对偏差在2 %范围以内。 相似文献