火控光电瞄准系统在惯导校正中的应用

充分,合理利用现有机载设备的信息资源来提高导航精度和可靠性是一项非常值得研究的课题,根据某型飞机火控光电瞄准系统中头盔瞄准具的测角原理和激光测距机的斜距信息,提出了用其校正惯导航向和位置坐标和数学模型,并对其应用作了进一步的讨论,此结论对于其它机地航信息的融合也具有一定的借鉴价值。     

Thousand fold concentration of an alkaloid in capillary zone electrophoresis by micelle to solvent stacking

In this paper, the co-solvent of methanol-water was used to facilitate the sodium dodecyl sulfate (SDS) micelles collapse, thereby inducing the on-line sample focusing technique of micelle to solvent stacking (MSS). To demonstrate this stacking method, the mechanism of micelles collapse in co-solvent was discussed. The details of the required conditions were investigated and the optimized conditions were: running buffer, 20mM H(3)BO(3) and 20mM NaH(2)PO(4) solution (pH 4.0); micellar sample matrix, 20mM SDS, 20mM H(3)BO(3) and 20mM NaH(2)PO(4) solution (pH 4.0); co-solvent buffer, 20mM H(3)BO(3) and 20mM NaH(2)PO(4) in methanol/water (90:10, v/v). The validity of the developed method was tested using cationic alkaloid compounds (ephedrine and berberine) as model analytes. Under the optimized conditions, this proposed method afforded limits of detection (LODs) of 0.5 and 1.1ng/mL with 300 and 1036-fold improvements in sensitivity for ephedrine and berberine, respectively, within 15min.     

Peak parking method for measurement of molecular diffusivity in liquid phase systems

The combination of series of measurements of band broadening made with the peak parking (PP) method, using successively an open capillary tube and a HPLC column, gives a convenient procedure for the measurement of the molecular diffusivity (D_m) of compounds in solutions, of their axial dispersion coefficient (D_ax,m) in chromatographic columns, and of the tortuosity or obstructive factor of the column bed. The molecular diffusivity measured for benzene in methanol was in excellent agreement with literature data. The ratio of the axial dispersion coefficient to this diffusivity gives the obstructive factor (γ_m) of the packed bed, which was 0.74 for the column used. The values of D_m in other solutions were obtained from the D_ax,m values measured by the PP method, by correcting the D_ax,m values with the γ_m value. The D_m values determined by this method were in good agreement with those previously reported or estimated using literature correlations. These results showed that the PP method is effective for the experimental measurement of D_m.     

可在线应用的大口径溶胶-凝胶膜光学元件激光清洗工艺研究（特邀）

在高功率激光装置中,光学元件表面的污染物会降低光束质量甚诱导光学元件损伤。针对装置中受污染的镀有SiO₂溶胶-凝胶增透膜的大口径真空隔离片（430 mm×430 mm）,使用波长为355 nm的Nd:YAG脉冲激光器模拟在线激光清洗实验。实验中采用了单发次激光干式清洗与气流置换系统辅助的激光清洗系统,研究了关键特征参数对激光在线清洗效果的影响规律,获得了可用于激光在线清洗的工艺参数。光学元件的处理采用光学显微镜、暗场成像法表征以及图像处理软件分析。实验结果表明,激光在线清洗光学元件存在最佳工艺窗口。通过气流置换辅助的激光清洗方法后,相较于单纯的单发干式激光清洗,激光清洗能力有大幅提升。因此,气流置换系统辅助单发激光清洗能有效提高其清洗能力,为高功率激光装置中大口径光学元件表面污染物在线去除提供了一种有效手段。     

基于随机投影深度函数的停车场车辆提取方法

为精确提取露天停车场内颜色混杂的车辆,提出一种基于随机投影深度函数的车辆提取方法.随机投影深度函数可有效区分RGB彩色空间中数据集的数据中心与离群值,充分利用各车辆颜色特征的复杂性及其与停车场背景颜色特征的差异性,凸显具有离群值颜色特征的车辆.首先,利用随机投影深度函数对彩色遥感影像中各像素颜色特征进行排序得到深度场影像;然后,对深度场影像做形态学闭运算并选取合适的随机投影深度值作为阈值,二值化闭运算后的深度场影像,实现车辆初始提取;最后,结合决策树分析与形态学运算实现车辆精确提取.实验结果表明,随机投影深度函数可有效处理彩色遥感影像中各种颜色车辆所表现的\"同物异谱\"现象,在深度场影像中凸显不同颜色的车辆,有效提高车辆提取效率;辅助以简单的后处理可实现遥感影像中不同场景停车场车辆提取.     

辅助光注入下半导体光放大器的快慢光性能

随着全光网络的快速发展,快慢光技术受到了广泛关注。为了研究半导体光放大器(SOA)的快慢光效应,文章构建了辅助光注入半导体光放大器的理论模型。比较了辅助光注入SOA前后,直流电流、调制电流、调制频率、相移以及增益系数等参数对相位延时量的影响。仿真结果表明：辅助光的注入使输出信号光由慢光变为快光,辅助光功率越强,效果越明显。同时,注入辅助光信号后,直流电流越大,相位延时量越大;调制电流、调制频率、相移及增益系数越大,相位延时量越小。     

一种车脸识别算法的研究与应用

基于车牌识别技术的停车场收费系统存在无牌车无法自动扣费以及套牌车逃费等问题。针对这一问题,需要基于车牌之外的其它特征来对车辆进行自动准确地识别。车脸能够有效表达车辆的特征信息,因此文中提出了一种基于卷积神经网络的车脸识别算法,该算法可以根据车脸图像自动准确地识别车辆,有效解决车辆身份识别中过度依赖于车牌的问题。实验结果表明,该算法的车脸识别准确率可以达到94.23%,明显优于传统的车脸识别算法,证明了该算法的可行性。最后,将车脸识别技术融合进智能停车场收费系统,可以有效地解决无牌车无法自动扣费和套牌车逃费的问题。     

Surface modification of a titanium alloy with a phospholipid polymer prepared by a plasma-induced grafting technique to improve surface thromboresistance

To improve the thromboresistance of a titanium alloy (TiAl₆V₄) surface which is currently utilized in several ventricular assist devices (VADs), a plasma-induced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) was carried out and poly(MPC) (PMPC) chains were covalently attached onto a TiAl₆V₄ surface by a plasma induced technique. Cleaned TiAl₆V₄ surfaces were pretreated with H₂O-vapor-plasma and silanated with 3-methacryloylpropyltrimethoxysilane (MPS). Next, a plasma-induced graft polymerization with MPC was performed after the surfaces were pretreated with Ar plasma. Surface compositions were verified by X-ray photoelectron spectroscopy (XPS). In vitro blood biocompatibility was evaluated by contacting the modified surfaces with ovine blood under continuous mixing. Bulk phase platelet activation was quantified by flow cytometric analysis, and surfaces were observed with scanning electron microscopy after blood contact. XPS data demonstrated successful modification of the TiAl₆V₄ surfaces with PMPC as evidenced by increased N and P on modified surfaces. Platelet deposition was markedly reduced on the PMPC grafted surfaces and platelet activation in blood that contacted the PMPC-grafted samples was significantly reduced relative to the unmodified TiAl₆V₄ and polystyrene control surfaces. Durability studies under continuously mixed water suggested no change in surface modification over a 1-month period. This modification strategy shows promise for further investigation as a means to reduce the thromboembolic risk associated with the metallic blood-contacting surfaces of VADs and other cardiovascular devices under development.     

停车场规划的分片凸规划-建模、算法及应用

本研究停车场选址问题。本抓住主要矛盾，建立实用停车场选址的分片凸规划模型。设计往复调整、下降迭代相结合的算法。并在常州市交通管理规划应用中取得了良好的效果。     

Parking buses in a depot with stochastic arrival times

Given buses of different types arriving at a depot during the evening, the bus parking problem consists of assigning these buses to parking slots in such a way that they can be dispatched adequately to the next morning routes without moving them between their arrivals and departures. In practice, the bus arrival times deviate stochastically from the planned schedule. In this paper, we introduce for this problem two solution approaches that produce solutions which are robust to variations in the arrival times. The first approach considers that each arrival can deviate from its planned arrival order (sooner or later) by at most k positions, where k is a predefined parameter. In the second approach, the objective aims at minimizing the expectation of a function positively correlated with the number of buses that make the planned solution infeasible because they arrive too late or too early. In both approaches, the problem is modeled as an integer linear program that can be solved by a commercial mip solver. Computational results obtained on instances derived from a real-world dataset are reported.