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171.
综合考虑了溶质元素与基体元素的原子半径、电负性以及外层电子数的立方根对溶质元素固溶度的影响,推导出二元合金的固溶度定量方程,提出了多元高温合金固溶极限曲线的预测新方法,并将其应用于计算镍基和钴基三元合金相图的γ/(γ+σ)相界和γ(γ+μ)相界。结果表明,计算的固溶极限曲线与已知相图的固溶极限曲线较吻合,与Md值法计算的相界比较,该方法具有较高的精度。 相似文献
172.
Li-xue Zou Shao-yan CuiJian Zhong Zong-chun YiYan Sun Yu-bo FanFeng-yuan Zhuang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
Hematopoietic progenitor cell proliferation can be alternated on either spaceflight or under simulated microgravity experiments on the ground; however, the underlying mechanism remains largely unknown. In the present study, we have demonstrated that exposure of human erythropoietin (EPO)-dependent leukemia cell line UT-7/EPO cells to conditions of simulated microgravity with a rotary culture instrument significantly inhibited the cellular proliferation rate. Adding higher concentrations of EPO to the culture medium failed to improve the inhibitory status. Cell apoptosis was detected by fluorescence staining of cell nuclei and a flow cytometry assay using Annexin V/PI double staining. This microgravity-induced apoptosis in UT-7/EPO cells could be blocked by a pancaspase inhibitor Z-VAD-FMK. Immunoblotting demonstrated that rotary culture resulted in a reduction of the expression of Bcl-xL, an anti-apoptotic protein, and the cleavage of caspase-3. Furthermore, rotary culture reduced surface localization and protein content, as well as the mRNA expression of erythropoietin receptor (EPOR) of UT-7/EPO. Take together, the findings indicated that simulated microgravity may induce mitochondrial related apoptosis of UT-7/EPO cell through depressing the EPO–EPOR pathway. 相似文献
173.
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175.
Zhen Zhong Fei Li Jianguo Yan Peng Yan James M. Dohm 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
This paper presents a FORTRAN computer program. The program as code will be used for lunar parameter inversions based on gravity/topography admittance. This will be done by assuming that the lunar lithosphere is modeled as a thin elastic spherical shell. The parameters discussed here include; load ratio, crustal thickness, subsurface load depth, crustal density and elastic lithosphere thickness. The admittance of the best-fitting model can be found through automatically adjusting misfits between one theoretical admittance and an observed one. The results in this paper indicate that this research’s theoretical model is reasonable for exploring the best-fitting parameters. In addition, this code is not only able to automatically and simultaneously calculate the global optimum solution of the parameters studied, but also performs well in computational speed. The code can be easily modified to include more parameter inversions; such as the inversion for subsurface density anomaly and the case of considering infilling material in some lunar mare basins. 相似文献
176.
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178.
为了降低飞机限时派遣(TLD)的运行成本,提出了全权限数字式电子控制(FADEC)系统TLD分析的运行成本优化方
法。构建了TLD分析的典型马尔可夫模型,推导了该模型各状态稳态频度公式,从而建立了系统单位时间运行成本与派遣时间间
隔的函数关系,并以此作为运行成本优化的目标函数;推导了发动机控制系统平均安全性水平表达式,建立了平均安全性水平对
派遣时间间隔的约束。针对FADEC系统建立了3种不同的形式的系统单位时间运行成本函数模型,并提出了相应的派遣间隔决
策建议。结果表明:应用基于成本优化的FADEC系统TLD分析方法进行带故障派遣决策,能够在满足安全性要求的情况下,降低
飞机运行成本。 相似文献
179.
Li-xue Zou Shao-yan CuiJian Zhong Zong-chun YiYan Sun Yu-bo FanFeng-yuan Zhuang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
Hematopoietic progenitor cell proliferation can be altered in either spaceflight or under simulated microgravity experiments on the ground, however, the underlying mechanism remains unknown. Our previous study showed that exposure of the human erythropoietin (EPO)-dependent leukemia cell line UT-7/EPO to conditions of simulated microgravity significantly inhibited the cellular proliferation rate and induced cell apoptosis. We postulated that the downregulation of the erythropoietin receptor (EPOR) expression in UT-7/EPO cells under simulated microgravity may be a possible reason for microgravity triggered apoptosis. In this paper, a human EPOR gene was transferred into UT-7/EPO cells and the resulting expression of EPOR on the surface of UT-7/EPO cells increased approximately 61% (p < 0.05) as selected by the antibiotic G418. It was also shown through cytometry assays and morphological observations that microgravity-induced apoptosis markedly decreased in these UT-7/EPO–EPOR cells. Thus, we concluded that upregulation of EPOR in UT-7/EPO cells could inhibit the simulated microgravity-induced cell apoptosis in this EPO dependent cell line. 相似文献
180.