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81.
简要介绍了“风云二号”静止气象卫星的地面应用系统、主要包括指令控制与数据接收站、数据处理中心、卫星运行控制中心三大组成部分以及三者之间的信息流程,最后介绍了由该系统输出的气象产品。  相似文献   
82.
在推导了多冲量最优解的必要条件的基础上,给出了一种卫星相位保持的多冲量次优控制方法。由于摄动和截断误差等对控制的影响,在多次冲量的求解时应该使用中间修正。计算表明,加中间修正的多冲量次化控制方法具有很好的鲁棒性。  相似文献   
83.
车载遥测跟踪站天线展开后,需要进行远场标校复查。由于受标校距离、天线仰角以及周围环境等各种条件的限制,使得主天线、引导天线的光电轴匹配检查难以保证精度要求,从而影响跟踪性能。针对这些问题,本文提出在近场条件下直接悬挂信标机进行标校复查,以保证光电轴匹配精度。并针对YQ- 312 S频段遥测跟踪车载站的实际推出角度转换公式。最后给出实例  相似文献   
84.
在实际应用中往往采用多测向站来测定位置信息。对多个测向站测量数据的综合处理,关系到如何正确应用所得测向数据信息的重要问题。针对多个测向站的冗余方案,给出了数据融合的应用方法。  相似文献   
85.
随着民航机场建设的加强,机场导航台遥控方式的选择渐渐提上议程。针对无线控遥的特点和功能,提出了利用以PC机为主的无线遥控原理的硬件模型。  相似文献   
86.
In its function as an ITRS Combination Centre, DGFI is in charge with the computation of an ITRF2008 solution. The computation methodology of DGFI is based on the combination of datum-free normal equations (weekly or session data sets, respectively) of station positions and Earth orientation parameters (EOP) from the geodetic space techniques DORIS, GPS, SLR and VLBI. In this paper we focus on the DORIS part within the ITRF2008 computations. We present results obtained from the analysis of the DORIS time series for station positions, network translation and scale parameters, as well as for the terrestrial pole coordinates. The submissions to ITRF2008 benefit from improved analysis strategies of the seven contributing IDS analysis centres and from a combination of the weekly solutions of station positions and polar motion. The results show an improvement by a factor of two compared to past DORIS data submitted to ITRF2005, which has been evaluated by investigating the repeatabilities of position time series. The DORIS position time series were analysed w.r.t. discontinuities and other non-linear effects such as seasonal variations. About 40 discontinuities have been identified which have been compared with the results of an earlier study. Within the inter-technique combination we focus on the DORIS contribution to the integration of the different space geodetic observations and on a comparison of the geodetic local ties with the space geodetic solutions. Results are given for the 41 co-location sites between DORIS and GPS.  相似文献   
87.
Molecular biology experiments on the International Space Station (ISS) continue to face challenges of sample harvesting and sample return to earth for post flight analysis; however, the use of Kennedy Space Center Fixation Tubes filled with RNALater has proven to be a robust solution to many of these challenges. While it is clear that one direction of future spaceflight experimentation may be towards enhanced on-orbit analytical capabilities, the rapid progress of earth-bound analytical capacity dictates that facile return of molecular biology samples from the ISS will continue to be a mainstay of space life sciences research and flight operations. In this paper we present a case study of the successful performance of KFTs and RNALater over a broad set of operational conditions of ascent configuration, on-orbit experiment use, on-orbit storage and sample return configurations that are unique to ISS current operations and constraints. We also provide observations on performance limits and discuss deployment opportunities and scenarios that are consistent with continued successful ISS molecular biology experimentation.  相似文献   
88.
在固定单站无源定位算法中,基于角度(Direct of Arrival)、角度变化率(Direct of Arrival Rate-of-Change)、多普勒频率(Doppler Frequency)和多普勒频率变化率(Doppler Frequency Rate-of-Change)4个观测信息实现定位(即DDFRC定位)算法仅通过单次观测即可实现对目标辐射源的定位。文中通过转移观测的卡尔曼滤波对定位结果进行平滑,较原有算法拥有更好的跟踪效果。同时,对定位误差进行了定量分析,并将距离信息引入算法的仿真分析之中,详细讨论了各个观测量误差在不同距离时对算法定位性能的影响,根据仿真结果,结合定位误差的定量分析对算法性能做出评价。通过仿真分析,得到了定位算法对不同距离下各参数的精度要求,从而为在实际系统中使用该定位算法提供了参考。  相似文献   
89.
Barley seeds were exposed to outer space for 13 months in a vented metal container without a climate control system to assess the risk of physiological and genetic mutation during long-term storage in space. The space-stored seeds (S0 generation), with an 82% germination rate in 50 seeds, lost about 20% of their weight after the exposure. The germinated seeds showed normal growth, heading, and ripening. The harvested seeds (S1 generation) also germinated and reproduced (S2 generation) as did the ground-stored seeds. The culm length, ear length, number of seed, grain weight, and fertility of the plants from the space-stored seeds were not significantly different from those of the ground-stored seeds in each of the S0 and S1 generation. Furthermore, the S1 and S2 space-stored seeds respectively showed similar β-glucan content to those of the ground-stored seeds. Amplified fragment length polymorphism analysis with 16 primer combinations showed no specific fragment that appears or disappears significantly in the DNA isolated from the barley grown from the space-stored seeds. Though these data are derived from nine S0 space-stored seeds in a single exposure experiment, the results demonstrate the preservation of barley seeds in outer space for 13 months without phenotypic or genotypic changes and with healthy and vigorous growth in space.  相似文献   
90.
提出了利用两平面反射镜多次反射来虚拟室外基线场,在室内完成检定光电测距仪及全站型电子速测仪测距部分的解决方案;在现有技术的层面上对该方案所面临的技术难题进行了探讨,对其可行性进行了论证;对该方案实施1000 m测长的不确定度进行了详细的分析和计算,得出了该方案完全可行的结论.  相似文献   
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