新一代便携式飞机称重系统的研制及应用

介绍了一种新研制出的便携式飞机称重系统，较详细的介绍了系统有很低的原理及应用。     

Plant mineral nutrition,gas exchange and photosynthesis in space: A review

Successful growth and development of higher plants in space rely on adequate availability and uptake of water and nutrients, and efficient energy distribution through photosynthesis and gas exchange. In the present review, literature has been reviewed to assemble the relevant knowledge within space plant research for future planetary missions. Focus has been on fractional gravity, space radiation, magnetic fields and ultimately a combined effect of these factors on gas exchange, photosynthesis and transport of water and solutes.     

Flight strategy optimization for high-altitude long-endurance solar-powered aircraft based on Gauss pseudo-spectral method

Solar-powered aircraft have attracted great attention owing to their potential for longendurance flight and wide application prospects.Due to the particularity of energy system, flight strategy optimization is a significant way to enhance the flight performance for solar-powered aircraft.In this study, a flight strategy optimization model for high-altitude long-endurance solar-powered aircraft was proposed.This model consists of three-dimensional kinematic model,aerodynamic model, energy collection model, energy store model and energy loss model.To solve the nonlinear optimal control problem with process constraints and terminal constraints, Gauss pseudo-spectral method was employed to discretize the state equations and constraint equations.Then a typical mission flying from given initial point to given final point within a time interval was considered.Results indicate that proper changes of the attitude angle contribute to increasing the energy gained by photovoltaic cells.Utilization of gravitational potential energy can partly take the role of battery pack.Integrating these two measures, the optimized flight strategy can improve the final state of charge compared with current constant-altitude constant-velocity strategy.The optimized strategy brings more profits on condition of lower sunlight intensity and shorter daytime.     

浅谈Bell－206直升机常规试飞

提出了常规试飞应把握的三个环节（做好试飞准备、掌握试飞方法、严格试飞标准）和常规试飞的主要项目（测试和调整旋翼与尾桨震动度、检查和调整旋翼自转转速、检查和调整操纵系统间隙与摩擦力、检查和校验发动机功率）及方法，为直升机试飞员和有关工程技术人员提供参考。     

正态单元的双边可靠性Bayes近似下限的计算方法

提出了正态单元双边可靠性性的Ｂａｙｅｓ近似下限的计算方法，该方法的精度高于经典法且偏保守。最后给出了若干实例的计算结果。     

PID在线自动整定法在台式燃料炉微机控制中的应用

本文以开原化工机械厂台式燃料炉微机控制为例，从频率分析的角度、阐述了PID控制规律，并针对常规的PID控制中存在的问题，提出了借用选择性强的ITAE（the integral of time-multiplied absolute-value of error criteion）准则，对其实现了在线自动调整，并给出了计算机在线自动整定PID控制算法中的最佳参数。     

美国宪法中的“贸易条款”

从1787年美国宪法制定至今已有200多年，这部牛车时代制定的不过8000字的宪法修改很少，却能够适应逐步形成的现代工业社会的需要，主要原因是宪法中的某些重要措辞如“贸易条款”、“必要与适当”、“正当程序”及“诚实信用”等极富弹性。美国宪法第1和第8款第3项的“贸易条款”最集中地体现了它的价值。因此，了解美国宪法中的“贸易条款”对于认识美国宪法和法律具有重要意义。     

空间站柔性太阳电池翼对日跟踪控制

空间站柔性太阳电池翼高稳定对日跟踪驱动控制,对于保障空间站长期在轨能源安全和平稳运行具有重要意义。在推导柔性太阳电池翼动力学模型、柔性体模态分析和截断、Alpha对日定向装置机电系统模型、非线性传动系统模型的基础上,对空间站柔性太阳电池翼对日跟踪控制系统进行设计。采用Heaviside五次样条变速规划、位置和速度两级闭环、速度环陷阱滤波器柔性振动抑制的组合方案,实现空间站柔性太阳电池翼高稳定驱动控制。通过对典型工况的仿真校核,验证所设计的控制方案可实现跟踪精度优于0.3°、速度偏差±0.005(°)/s、稳定度优于7%@0.065(°)/s的性能指标。同时,Alpha对日定向装置的启动和变速过程中驱动力矩不大于30 N·m,稳速运行期间驱动力矩不大于5 N·m。各项性能指标要好于国际空间站Alpha对日定向装置,满足使用要求。     

Scramjet尾喷管几何调节方案的计算与实验研究

高超声速飞行器飞行接力点和巡航结束点尾喷管冷、热态俯仰力矩差较大,给飞行器的飞行姿态控制造成严重影响。为了减小喷管冷、热态俯仰力矩差,提出了在喷管上膨胀面末端增加移动板进行调节的方案,并进行了详细的三维数值模拟和相应的风洞缩比冷流实验研究。计算结果表明,Ma=4.5时,调节移动板伸出400mm,喷管冷、热态力矩差最大减小21.74%,推力系数损失1.64%;Ma=6.5时,调节移动板喷管冷、热态力矩差可降低77.59%,而推力系数只减小1.35%,调节收益非常明显。最后通过将喷管各调节状态下的冷流缩比实验壁面压力数据与计算结果的对比,证明了该调节方案的计算方法及其结果是可靠的,同时得出该调节方案可以有效地降低冷、热态力矩差的结论。      

基于节流阀模型跨声速轴流压气机失速特性研究

为了研究跨声速轴流压气机失速特性,基于节流阀模型,对跨声速轴流压气机转子NASA Rotor 37进行了数值计算,得到了整个失速过程中的流场分布.结果表明,随着阀门进一步关小,压气机逐渐进入旋转失速,在失速发展过程中,失速团逐渐扩展至10％ ～ 20％叶高,并绕着旋转轴以低于转子转速同方向旋转.