新机研制争速度 当年首飞上蓝天──加速教11工艺准备工作的几项措施

论述了南飞公司为加速教11飞机的研制，对工艺准备工作所采取的几项措施，主要是：按研制顺序倒排计划；控制二装需求总量；实行阶段承包；开展平行工程；实行系统管理。     

象征型拟微分算子的L~2－有界性

证明了象征型拟微分算子的一个Ｌ２有界性定理，其中象征ａ（ｘ，ξ）关于ｘ的正则性条件被进一步减弱了。在某种意义下，该结果给出了定理Ａ与定理Ｂ之间的联系。     

不确定串联非线性系统具有L2增益的鲁棒自适应控制

研究了一类含有未知参数和干扰的串联非线性系统H∞鲁棒自适应控制问题。结合H∞控制和自适应控制，基于李亚普诺夫函数递推设计方法设计了H∞状态反馈自适应控制器，并且得出了控制器的精确解，避免了求解HJI不等式设计控制器的困难。该控制器不仅保证闭环系统ISS稳定，而且使得系统对于所有允许的参数不确定从干扰输入以可控输出的L2增益不大于给定的值。仿真结果表明了所设计的控制器的可行性和有效性。     

On the correlation of the solar wind observed at the L5 point and at the Earth

The L5 point is a promising location for forecasting co-rotating high-speed streams in the solar wind arriving at the Earth. We correlated the solar wind data obtained by the Nozomi spacecraft in interplanetary space and by the Advanced Composition Explorer (ACE) at the L1 point, and found that the correlation is significantly improved from that of the 27-day recurrence of ACE data. Based on the correlation between the two spacecraft observations, we estimated the correlation of the solar wind velocity between the L5 point and at the Earth, and found that the correlation coefficient was about 0.78 in late 1999, while that of the 27-day recurrence was 0.51. Eighty-eight percent of the velocity difference falls within 100 km/s between the L5 point and the Earth. This demonstrates the potential capability of solar wind monitoring at the L5 point to forecast the geomagnetic disturbances 4.5 days in advance.     

基于Gauss-Newton法的L1数据拟合

在数据拟合中，当个别数据存在较大测量误差时，采用Ｌ１准则对数据进行拟合要优于最小二乘准则。本文通过建立Ｌ１准则与最小二乘准则之间的关系，给出了一种基于Ｇａｕｓｓ－Ｎｅｗｔｏｎ法的Ｌ１数据拟合自满。计算结果表明，该方法易于理解，便于编程，具有一定的理论意义和现实意义。     

检漏方法的灵敏度估算

为方便地选择检漏方法 ,设计检漏系统和估算检漏系统的灵敏度 ,文章推导了一些常用检漏方法的灵敏度估算公式 ,这些公式在航天密封产品的检漏实践中具有实用性     

基于S3000L的MTA方法在民用飞机领域的应用研究

目前大多数国际主流民用飞机制造商均开始采用S3000L标准进行综合后勤保障设计,以提高飞机的可靠性和维修性。本文通过研究维修任务分析的原理和方法,结合民用飞机研制经验制定出一套可行、有效的维修任务分析操作程序,并运用实例进行了验证和说明,为国内开展民用飞机维修工程分析及其他相关保障工作提供了参考。     

Influence of the interaction between light intensity and CO2 concentration on productivity and quality of spinach (Spinacia oleracea L.) grown in fully controlled environment

The effects of the factorial combination of two light intensities (200 and 800 μmol m⁻² s⁻¹) and two CO₂ concentrations (360 and 800 ppm) were studied on the productivity and nutritional quality of spinach (Spinacia oleracea L.) grown under controlled environment. After 6 weeks within a growth chamber, spinach plants were sampled and analyzed for productivity and quality. There were no statistically significant interactions between the effects of light and CO₂ for all of the variables studied, except for the nitrate and oxalic acid content of the leaves. High light and high CO₂ independently one from the other, promoted spinach productivity, and the accumulation of ascorbic acid, while their interactive effect limited the accumulation of nitrate and oxalic acid in the spinach leaves. The results highlight the importance of considering the effects of the interaction among environmental variables on maximizing production and the nutritional quality of the food when cultivating and modeling the plant response in controlled environment systems such as for bioregenerative life support.     

基于经济性的公务机升阻特性优化展望

在可预见的未来,高性能、高效能的公务机将在世界公务机市场中日益重要。基于提高公务机空气动力效率的目的,讨论了未来可能应用于工程实际的升阻优化技术的优缺点,并展望了其应用前景。     

嫦娥二号探测器轨道确定与支持

针对嫦娥二号探测器直接进入地月转移轨道、距月面100km高度捕获月球、完成既定任务后飞往日地第二拉格朗日平动点等飞行轨道方面的新特点,分析了定轨预报策略,利用事后精密轨道,全面评估了关键变轨点定轨预报和变轨后快速定轨的精度,其中,近月制动前3h定轨预报至近月点的位置误差为1km,速度误差为 0.3m/s 。利用不同月球引力场模型进行环月轨道精密定轨,根据实测数据残差分析和精密星历比对的结果,采用SGM100h引力场模型的定轨残差均方根最大。此外,针对嫦娥二号扩展任务,分析了不同测轨条件下的定轨精度,测量数据残差分析结果表明,在扩展任务中途修正前的定轨弧段内,测距、时延和时延率数据的残差分别为5m,5ns和1ps/s。