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311.
312.
典型直升机是实施立体突击作战的重要力量,在火力支援、立体补给、综合勤务保障等方面发挥着重要作用。针对其构造形式和作战使用要求,直升机在低空超低空低速执行任务时,使用场景中面临低空和地面的多种威胁,致使其服役环境和作战环境更加恶劣。本文通过分析直升机在作战中面临的威胁特点,阐述在直升机设计和使用维护过程中,综合防护能力、环境适应能力、战伤抢修能力对直升机作战完整性的影响,通过合理设计机体结构,提升生存能力,提升海上、高原、沙尘等环境适应能力,建立完备的战伤抢修能力来保证直升机使用的完整性,满足使用需求。 相似文献
313.
High-efficiency aircraft antiskid brake control algorithm via runway condition identification based on an on-off valve array 总被引:1,自引:1,他引:1
The aircraft antiskid braking system is an important hydraulic system for preventing tire bursts and ensuring safe take-off and landing. The brake system adjusts the force applied on the brake discs by controlling the brake pressure. Traditional aircraft antiskid braking systems achieve antiskid performance by controlling the braking pressure with an electrohydraulic servo valve. Because the pilot stage of an electrohydraulic servo valve is easily blocked by carbonized hydraulic oil, the servo valve would become a dangerous weak point for aircraft safety. This paper proposes a new approach that uses an on-off valve array to replace the servo valve for pressure control. Based on this new pressure control component, an efficient antiskid control algorithm that can utilize this discontinuous feature is proposed. Furthermore, the algorithm has the ability to identify the runway circumstances. To overcome the discontinuity in the process of using an on-off valve array, the Filippov framework is introduced. The conditions of convergence of the system are also discussed. The results of the digital simulations and the hardware-in-the-loop (HIL) braking experiments are used to verify the efficiency and stability of the proposed control algorithm. The method also proves that the on-off valve array can replace the servo valve perfectly as a new type of antiskid braking pressure control component. 相似文献
314.
Dmitri Nikolaevich Severov Valentina Pshennikov Alexsandr Vasilievich Remeslo 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
Fronts and thermohaline structure of the Brazil–Malvinas Confluence System (BMCS) are studied from climatic data, “Marathon Exp. Leg.8, 1984” data, and Sea surface temperature (SST) data base “ds277-Reynolds” (1981–2000). The South Atlantic Central Water (SACW) is divided in two main types: tropical (TW) and subtropical water (ST). Water masses, Fronts, Inter-Frontal and Frontal Zones are analysed and classified: (a) the water masses: Tropical Low-Salinity Water, Tropical Surface Water, Tropical Tropospheric Water, Subtropical Low-Salinity Water, Subtropical Surface Water, Subtropical Tropospheric Water. T,S characteristics of intermediate, deep and bottom water defined by different authors are confirmed and completed; (b) the Inter-Frontal Zones: Tropical/Brazil Current Zone, Subtropical Zone and Subantarctic Zone; (c) the Frontal Zones: Subtropical, Subantarctic and Polar, and (d) the Fronts: Subtropical Front of the Brazil Current, Principal Subtropical Front, North Subtropical Front, Subtropical Surface Front, South Subtropical Front, Subantarctic Surface Front, Subantarctic Front and Polar Front. Several stable T–S relationships are found below the friction layer and at the Fronts. The maximum gradient of the oceanographic characteristics occurs at the Brazil Current Front, which can be any of the subtropical Fronts, depending on season. Minimum mean depth of the pycnocline coincides with the Fronts of the BMCS, indicating the paths of low-salinity shelf waters into the open ocean. In the work it is shown how to recover the horizontal and vertical thermohaline structure of waters from satellite data RSMAS SST. 相似文献
315.
M. Abada-Simon A. Lecacheux T. S. Bastian J. A. Bookbinder G. A. Dulk 《Space Science Reviews》1994,68(1-4):291-292
We report the first millimetric detections of the magnetic cataclysmic variable AE Aquarii, accompanied by contemporaneous microwave observations. These data show that the time-averaged spectrum is well fit by a power-law which extends to mm wavelengths. We suggest that the spectrum is consistent with that expected from a superposition of flare-like events. 相似文献
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对中国民航货运市场的特点及其发展状况进行了对比分析,剖析了国民经济与民航货运的内在关系,从而建立了货邮运输量和货邮周转量的非线性回归模型,预测出2005-2020年的中国航空货邮运输量和周转量,为中国民航货运部门进行决策提供了一定的科学依据。 相似文献
318.
无人驾驶直升机遥测遥控与电子系统设计 总被引:3,自引:0,他引:3
介绍了某型无人驾驶直升机遥测遥控与电子系统设计研制,系统要求、总体结构与工作过程,系统设计中的技术问题与解决方案,该系统已经研制成功并得到应用。 相似文献
319.
结合INMARSAT-4F1早期轨道支持任务,介绍了INMARSAT测控网的结构和任务配置,给出了测控网发生故障时的处理方法以及实际应用情况。最后根据故障诊断理论,分析了航天测控网的故障特点。 相似文献
320.
NASA深空网(DSN)的现状及发展趋势 总被引:10,自引:0,他引:10
详细介绍了美国深空网的发展过程、目前的状况以及未来的主要发展计划。 相似文献