相对论性离子束（环束）流引起的电磁不稳定性

在相对论性框架下，研究了冷离子流产生的右旋共振模，非共振模电磁不稳定性的特征结果表明，非共振模不稳定性增长率受离子流初始参数影响较大，而右旋共振模的增长率则受离子流初始参数影响较小。此结果可应用于太阳高能离子流通过低日冕区和地球磁层辐射带俘获的高能质子情形。     

民用运输类飞机最大可用速率抬前轮试飞技术研究

最大可用速率抬前轮试飞是验证抬前轮速度与起飞安全速度的重要依据,也是难度较大、风险较高的试验项目。以起飞动力学分析为基点,得出最大可用速率抬前轮试飞可能达到的最大迎角,并结合相应的适航审定条款,分析了影响该科目试飞的主要因素,给出了最大可用速率抬前轮试飞技术分析和数据处理方法。     

电机瞬态转速测试

介绍了一种利用单片机和光电转速传感器来测量电机瞬态转速及电机转速变化过程的方法。该方法简单、反应时间快、准确度高。     

用激光干涉技术测量转速的研究

叙述了一种新型转速激光干涉测量方法，详细分析了这种方法的工作原理，确定了本测量方法的转速测量范围，给出了实验结果。     

Design and Application of Discrete Sliding Mode Control with RBF Network-based Switching Law

This article proposes a novel approach combining exponential-reaching-law-based equivalent control law with radial basis function (RBF) network-based switching law to strengthen the sliding mode control (SMC) tracking capacity for systems with uncertainties and disturbances. First, SMC discrete equivalent control law is designed on the basis of the nominal model of the system and the adaptive exponential reaching law, and subsequently, stability of the algorithm is analyzed. Second, RBF network is used to form the switching law in a direct and online manner with sliding-mode-related inputs and by approximating evaluation function; and the method to adjust its parameters is devised. Finally, comparable experiments are carried out to verify the application of the proposed approach to an inner-axis driven by a direct current (DC) torque motor through extra-low speed servo for a high precision flight simulator, and the axis works under deteriorating conditions such as periodically fluctuating torques of motor, nonlinear friction, and time-varying model parameters. The results show that the combined SMC can effectively improve the servo performance, for instance, to a stable 0.000 08 (°)/s speed response, the tracking error would be within 0.000 08° in 98% of operating times. Moreover, the hybrid nature of the approach imparts the RBF network the features of removing offline training and ease to set initial parameters.     

Cluster observations showing the indication of the formation of a modified-two-stream instability in the geomagnetic tail

This study presents several observations of the Cluster spacecraft on September 24, 2003 around 15:10 UT, which show necessary prerequisites and consequences for the formation of the so-called modified-two-stream instability (MTSI). Theoretical studies suggest that the plasma is MTSI unstable if (1) a relative drift of electrons and ions is present, which exceeds the Alfvèn speed, and (2) this relative drift or current is in the cross-field direction. As consequences of the formation of a MTSI one expects to observe (1) a field-aligned electron beam, (2) heating of the plasma, and (3) an enhancement in the B-wave spectrum at frequencies in the range of the lower-hybrid-frequency (LHF). In this study we use prime parameter data of the CIS and PEACE instruments onboard the Cluster spacecraft to verify the drift velocities of ions and electrons, FGM data to calculate the expected LHF and Alfvèn velocity, and the direction of the current. The B-wave spectrum is recorded by the STAFF instrument of Cluster. Finally, a field aligned beam of electrons is observed by 3D measurements of the IES instrument of the RAPID unit. Observations are verified using a theoretical model showing the build-up of a MTSI under the given circumstances.     

UG在高速加工中的应用

高速加工(HSM)具有许多优点，被广泛应用在航空产品的数控加工中。但是使用高速加工技术，不仅要有适合高速加工的设备，选择适合进行高速加工的刀具，更为重要的是选择合理的编程策略。任何编程策略的不合理都会造成严重的后果。所以数控编程一直是高速加工的重点和难点。以UG软件为研究对象，作者提出了实现高速加工的数控编程的策略，并使用高速铣雕设备对生成的NG代码进行了加工，加工结果验证了NG代码是正确的、合理的。说明了采用合理的加工策略，使用UG软件可以实现高速加工的编程。     

一种测定大值的风速计

简单叙述了研制1种大风速值简易精密测量仪器原理和方法，并对测量误差进行了估算。     

A combined turbulent combustion model in studying a lean flameout process

A modification of the Zimont turbulent combustion model is presented; the modification makes it possible to describe processes in diffusion and homogeneous flame fronts as well as to take into account the influence of different factors that cause flame destabilization. The model is based on the equation for a reaction completeness extent (completeness of combustion). The model realization to simulate the premixed combustion is described and the modification of the turbulent combustion model is applied to simulate a process of flameout downstream of the flameholder.     

结冰对民用飞机飞行性能的影响分析

在获取民用飞机适航合格审定证明前,必须通过飞行试验,并在试验中演示验证民用飞机能在CCAR25部附录C确定的连续和间断的最大结冰状态下安全运行。基于此背景,计算并得到某型机两种构型在45min待机冰型下的飞行性能,与无冰状态下对应构型的飞行性能进行对比分析。结果表明,结冰对飞机的飞行性能具有较大的影响。