Selective creation of maximum coherence in multi-level Λ system

We consider the creation of the maximum Raman coherence in the six-level Λ system using optimal control theory. Optimal fields are designed for different initial conditions, resonant, and off-resonant, using the Krotov method including a reference field into the cost functional. Suppression of the population transfer to the intermediate level is achieved via an additional functional constraint which depends on the system dynamics. We demonstrate that the spectrum of the optimised fields has major contribution from the corresponding resonant frequencies independently of the choice of carrier frequency of the initial guess field. We also indicate that the pulse train emerges as a solution of the control problem of coherence optimisation in multi-level quantum systems.     

考虑最佳入口温度的多股流换热器网络循环优化

针对于多股流换热器网络的应用优势,本文在衍生网络优化方法基础上,提出了考虑最佳入口温度的多股流换热器循环优化方法,即利用多股流换热器网络小面积换热器合并而不产生固定投资费用这一特点,将优化结果中存在公用工程的流体返回到另一种流体的入口并与其入口流体进行循环优化。结果表明,这种优化方法能够进一步发挥多股流换热器网络的优点,得到年综合费用更小、运行费用更低的网络结构。     

自适应环境的机器人视觉伺服控制方法

机器人和机器视觉的迅速发展,使得基于视觉的智能机器人得到更加广泛的应用。机器视觉提高了机器人控制系统对环境的适应程度,但其适应程度也受到周围环境对机器视觉算法的影响。针对这一情况,本文对机器人视觉伺服控制系统中的机器视觉算法进行了改进,提出了一种基于帧间差分法的自适应环境的机器人视觉伺服控制方法,从而提高了控制系统对环境的自适应程度,提高了对机器人控制的精确度,实验和理论分析证明,该方法具有较大的应用前景和实用价值。     

Control of polarity and defects in the growth of AlN films on Si (111) surfaces by inserting an Al interlayer

We discuss the role of the Al interlayer in the suppression of pinhole formations and also look at the polarity transition of the AlN layers from N-polarity to Al-polarity when this Al interlayer is present. The AlN layers were grown by molecular beam epitaxy on an AlN nucleation layer. A thin Al interlayer was deposited on the initial nucleated AlN layer after the nitridation of the Al-soaked Si (111) substrates. The AlN layer with an Al interlayer showed a relatively smooth surface with a reduced density of pinholes compared with the AlN layer grown without an Al interlayer. In addition, the AlN layer with an Al interlayer showed some stacking faults in the interface between the Si substrate and the A1N layer. We also identify the polarity change of the AlN layer after the insertion of a thin Al interlayer from N-polarity to Al-polarity by chemical etching. A simple model is constructed to explain the polarity change and the pinhole suppression due to the Al interlayer.     

H基于模糊观测器参数摄动的耦合时空混沌H跟踪控制

由于子系统的时空耦合作用及参数的摄动性，实现参数摄动的耦合时空混沌的跟踪控制非常困难。然而模型未知的耦合时空混沌的每个子系统可由一系列模糊逻辑模型逼近，每个模糊逻辑模型代表子系统在特定运行点的局部线性化模型，同时考虑子系统状态的不可测性，采用模糊观测器来估计子系统的状态。基于模糊模型及状态观测器，计及混沌参数的摄动性，提出一种模糊跟踪控制方案，实现了参数摄动的耦合时空混沌的鲁棒跟踪控制，并将模糊跟踪控制表征为线性矩阵不等式问题，用线性矩阵不等式的凸优化方法求解控制器参数，确保系统的全局渐近稳定性。仿真验证了方案的有效性。     

RIBLL终端LASCAR闪烁体阵列探测器研制进展

介绍了RIBLL终端LASCAR闪烁体阵列探测器的工作原理和结构特点. 描述了为满足放射性核束实验的要求而对阵列所作的重要改进. 给出了LASCAR构型优化改造的工作设想和实施步骤. The principles and structure characteristics of LASCAR scintillator array detector at RIBLL terminal are described. Special emphases are laid upon the latest progress for the development of LASCAR array detector to meet the requirements of the RIB experiments. The working plan and steps for optimizing configuration of the LASCAR multi unit neutron scintillator array detector are also presented.     

含甲缩醛柴油喷雾和燃烧排放特性的试验研究

应用激光相位多普勒技术测量了含甲缩醛柴油喷雾的速度场和粒径场,在直喷式柴油机上研究了该含氧混合燃油的燃烧排放特性。结果表明,添加甲缩醛可改善柴油的雾化,增加喷雾轴线上的粒子速度,但减小喷雾锥角;同时以远大于其加入的比例降低柴油机排气烟度,但对氮氧化物的排放影响不大。柴油机采用甲缩醛作燃油添加剂时,需改造燃油系统。     

双轴晶体电光调制器的最优设计

运用新的线性电光效应的耦合波理论，对双轴晶体KTP电光调制器的温度特性进行了理论研究.找到了一个入射光波矢的方向，在该方向上，出射光光强不随温度的变化而变化，而且此方向在一定的角度范围内变动，温度的稳定性是可以保持的.还进一步对晶体的通光长度和外加电场的方向进行了筛选，实现了双轴晶体KTP电光调制器的最优设计. 关键词： 电光效应 耦合波理论 电光调制器 最优设计     

Aberration correction and its automatic control in scanning electron microscopes

An automatic aberration correction method has been implemented in scanning electron microscopes (SEM). Necessity of the automatic aberration correction is discussed. The procedure of the automatic aberration correction is explained in detail, where deconvolution techniques are used in order to extract probe information from SEM images. Due to the precise digitization and the usage of proper combinations of correction fields, linearity has been found between the amplitude of each aberration and the corresponding field strength. Experimental results are shown which demonstrate that the aberrations are corrected automatically by a linear feedback control method. After the automatic aberration correction, the image quality has been improved drastically.     

The optimal path of piston motion for Otto cycle with linear phenomenological heat transfer law

An Otto cycle engine with internal and external irreversibilities of friction and heat leakage, in which the heat transfer between the working fluid and the environment obeys linear phenomenological heat transfer law [q ∝△(T -1)], is studied in this paper. The optimal piston motion trajectory for maximizing the work output per cycle is derived for the fixed total cycle time and fuel consumed per cycle. Optimal control theory is applied to determine the optimal piston trajectories for the cases of with and w...