网络技术在箭载测量数据综合技术中的应用研究

交换式网络在数传能力、灵活性、扩展性等方面具有一定的优势,将其应用于箭载测量系统进行数据综合,对于提高系统性能意义重大。简要介绍现用箭载测量数据综合技术的实现原理,分析交换式网络技术特性,并从箭载设备的功能、拓扑结构、实时性能分析等方面对网络技术在箭载测量数据综合技术中的应用进行探索。     

大学生心理健康之情商水平分析

利用情绪稳定性测试量表，对我院2000级9个系130名大学生的情绪水平进行了测试。结果显示大学生情商水平较低，其中农村生、文科生和女生的情商水平低于城市生、理科生和男生。应采取有效措施，努力提高我院大学生的情商水平。     

基于优先级区间连接策略的抢占式线程池模型

通过阐述现有实时CORBA实现中使用的线程池模型,分析了这些模型在与优先级区间连接策略配合上存在的优缺点。提出了一种新的线程池模型,模型是针对实时CORBA规范优先级区间连接策略的抢占式线程池,能够更好地配合优先级区间连接策略,保证高优先级请求能得到及时的响应。     

Near real-time BDS GEO satellite orbit determination and maneuver analysis with reversed point positioning

The Geostationary Earth Orbit (GEO) satellite is a crucial part of the BeiDou Navigation Satellite System (BDS) constellation. However, due to various perturbation forces acting on the GEO satellite, it drifts gradually over time. Thus, frequent orbit maneuvers are required to maintain the satellite at its designed position. During the orbit maneuver and recovery periods, the orbit quality of the maneuvered satellite computed with broadcast navigation ephemeris will be significantly degraded. Furthermore, the conventional dynamic Precise Orbit Determination (POD) approach may not work well, because of a lack of publicly available satellite information for modeling the thrust forces. In this paper, a near real-time approach free of thrust forces modeling is proposed for BDS GEO satellite orbit determination and maneuver analysis based on the Reversed Point Positioning (RPP). First, the station coordinates and receiver clock offsets are estimated by GPS/BDS combined Single Point Positioning (SPP) with single-frequency phase-smoothed pseudorange observations. Then, with the fixed station coordinates and receiver clock offsets, the RPP method can be conducted to determine the GEO satellite orbits. When no orbit maneuvers occur, the proposed method can obtain orbit accuracies of 0.92, 2.74, and 8.30?m in the radial, along-track, and cross-track directions, respectively. The average orbit-only Signal-In-Space Range Error (SISRE) is 1.23?m, which is slightly poorer than that of the broadcast navigation ephemeris. Using four days of GEO maneuvered datasets, it is further demonstrated that the derived orbits can be employed to characterize the behaviors of GEO satellite maneuvers, such as the time span of the maneuver as well as the satellite thrusting accelerations. These results prove the efficiency of the proposed method for near real-time GEO satellite orbit determination during maneuvers.     

Efficacy of oxygen-supplying capacity of Azolla in a controlled life support system

Azolla shows high growth and propagation rates, strong photosynthetic O₂-releasing ability and high nutritional value. It is suitable as a salad vegetable and can be cultured on a multi-layered wet bed. Hence, it possesses potential as a fresh vegetable, and to release O₂ and absorb CO₂ in a Controlled Ecological Life Support System in space. In this study, we investigated the O₂-providing characteristics of Azolla in a closed chamber under manned, controlled conditions to lay a foundation for use of Azolla as a biological component in ground simulation experiments for space applications. A closed test chamber, representing a Controlled Ecological Life Support System including an Azolla wet-culture device, was built to measure the changes in atmospheric O₂ and CO₂ concentrations inside the chamber in the presence of coexisting Azolla, fish and men. The amount of O₂ consumed by fish was 0.0805–0.0831 L kg⁻¹ h⁻¹ and the level of CO₂ emission was 0.0705–0.0736 L kg⁻¹ h⁻¹; O₂ consumption by the two trial volunteers was 19.71 L h⁻¹ and the volume of respiration-released CO₂ was 18.90 L h⁻¹. Under 7000–8000 Lx artificial light and Azolla wet-culture conditions, human and fish respiration and Azolla photosynthesis were complementary, thus the atmospheric O₂ and CO₂ concentrations inside chamber were maintained in equilibrium. The increase in atmospheric CO₂ concentration in the closed chamber enhanced the net photosynthesis efficiency of the Azolla colony. This study showed that Azolla has strong photosynthetic O₂-releasing ability, which equilibrates the O₂ and CO₂ concentrations inside the chamber in favor of human survival and verifies the potential of Azolla for space applications.     

飞机设计选材专家系统的开发

在对飞机设计选材工作进行分析的基础上,提出基于浏览器/服务器(B/S,Browser/Service)结构的飞机设计选材专家系统总体框架和系统各功能的实现方式,并开发了系统的原型.该系统将基于规则、案例和模型的选材方法结合在一起,通过一个通用的推理机实现推理.该推理机功能通过CLIPS(C Language Integrated Production System)专家系统开发工具实现.该系统主要有3个工作步骤:选材的定性推理,材料检索和材料综合性能排序.用户可以方便地使用浏览器对系统进行访问和操作.该系统飞机机翼大梁选材实例验证了该系统的有效性,可对飞机设计人员的选材工作起指导作用.     

湿地松林和加勒比松林的土壤特性研究

李贻铨,陈宏峻,陈道东,等.火炬松和湿地松幼林施肥对土壤性质和叶片养分影响[J].林业科学,1999,35(1):95-100.

谭芳林,林捷,张水松,等.沿海沙地湿地松林地土壤养分含量及酶活性研究[J].林业科学,2003,39(1):169-173.

薛立,陈红跃,邝立刚.湿地松混交林地土壤养分、微生物和酶的研究[J].应用生态学报,2003,14(1):157-159.

薛立,吴敏,徐燕,等.几个典型华南人工林土壤的养分状况和微生物特性研究[J].土壤学报,2005,42(6):1017-1023.

王海英,宫渊波,陈林武.陵江上游不同植被恢复模式土壤微生物及土壤酶活性的研究[J].水土保持学报,2008,22(3):173-177.

薛立,邝立刚,陈红跃,等.不同林分土壤养分、微生物与酶活性的研究[J].土壤学报,2003,40(2):280-285.

陆耀东,薛立,曹鹤,等.去除地面枯落物对加勒比松林土壤特性的影响[J].生态学报,2008,28(7):3205-3211.

曹鹤,薛立,谢腾芳,等.华南8种人工林的土壤物理性质研究[J].生态学杂志,2009,28(4):620-625.

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薛立,陈红跃,徐英宝,等.混交林的土壤物理性质与微生物数量及酶活性的研究[J].土壤通报,2004,3-4(2):154-158.

薛立,李燕,屈明,等.火力楠、荷木和黎蒴林的土壤特性及水源涵养的研究[J].应用生态学报,2005,16(9):1623-1627.

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偏二甲肼组分变化对火箭发动机稳态工作性能的影响

通过建立液体发动机稳态工作模型与热力计算模型,利用最小二乘优化与迭代计算的方法,仿真研究了被空气部分氧化的偏二甲肼(UDMH)对泵压式液体火箭发动机的影响规律。结果表明,随着UDMH中二甲胺、偏腙和水含量的增加,推进剂混合比略有升高,发动机推力、燃烧室压强和燃烧室温度等参数有较明显下降。与传统地单纯分析推进剂能量性能相比,此方法更能准确表征在火箭发动机系统复杂的调节机制作用下,变质推进剂对发动机工作性能的影响。     

1700℃有氧环境下高超声速飞行器轻质防热材料隔热性能试验研究

文章针对高超声速飞行器需面临极端高温有氧热环境以及舱体表面单侧面受热的特点,建立了由硅钼发热体作为热源的红外辐射式超高温、时变、单侧面加热试验测试系统,开展了高达1700℃的有氧环境下高超声速飞行器轻质防热材料的隔热性能试验。另外,为了研究和优选高效隔热方式,对高超声速飞行器用单层轻质陶瓷隔热材料和陶瓷/纳米材料叠层复合结构在1700℃高温有氧环境下的隔热特性进行了试验测试;通过试验结果的对比分析,发现陶瓷/纳米材料复合叠层结构比单层轻质陶瓷材料的隔热效果提高近50%。