面向宽谱段共焦测量的消像差准直会聚方法EI北大核心CSCD

针对宽谱段定焦系统存在色散严重、像差较大的问题,提出一种面向宽谱段共焦测量的消像差准直会聚新方法。该方法利用全反射式结构抑制不同波长定焦时造成的色散效应,利用抛物面结构和环形光束抑制像差,在可见至红外宽谱段内实现了对光束的精确准直与会聚,相对于现有准直会聚方法可以消除色散且明显抑制像差。理论分析和初步实验表明：依据该方法构建的准直会聚系统在不同波长光源情况下聚焦点完全重合,定焦曲线旁瓣得到明显抑制,且定焦分辨力达到72.4μm@1 064 nm,接近环形光束聚焦情况下的理论计算极限。     

面向宽谱段共焦测量的消像差准直会聚方法

针对宽谱段定焦系统存在色散严重、像差较大的问题,提出一种面向宽谱段共焦测量的消像差准直会聚新方法。该方法利用全反射式结构抑制不同波长定焦时造成的色散效应,利用抛物面结构和环形光束抑制像差,在可见至红外宽谱段内实现了对光束的精确准直与会聚,相对于现有准直会聚方法可以消除色散且明显抑制像差。理论分析和初步实验表明:依据该方法构建的准直会聚系统在不同波长光源情况下聚焦点完全重合,定焦曲线旁瓣得到明显抑制,且定焦分辨力达到72.4μm@1 064 nm,接近环形光束聚焦情况下的理论计算极限。     

卫星激光测距中发射光路光机结构设计

在卫星激光测距过程中,为了保证望远镜系统接收更多的能量,必须压缩出射激光光束的发散角,减小照射到卫星上的激光光斑尺寸。激光发射系统的主要作用是就将激光器发出光束进行直径放大并准直,是卫星激光测距光机系统中的重要组成部分。在研制某型号卫星激光测距系统中,根据技术指标对两级扩束光学系统、机械结构以及二维电动调整机构进行了详细论述和设计。实践证明,该套系统的光学系统在进行激光光束扩束、准直的同时,通过二维电动调整机构实现了实时调整激光光束的出射方向,满足了设计指标的要求。     

一种激光连续变倍准直扩束系统的设计

介绍了国内外激光扩束系统的研究现状,阐述了低倍率扩束系统设计原理,选用没有内部焦点的倒置伽利略式望远镜系统结构设计了一个无焦变倍的激光扩束准直系统。在Zemax软件中实现变倍扩束系统初始结构的设计,基于Zemax的REAY优化函数对光学系统中透镜的曲率半径和间距进行优化,实现5~25倍的连续变倍激光扩束。不同倍率下的波像差最大均方根值均小于λ/40,设计结果满足像质要求。经工艺分析,该设计符合加工的工艺要求,系统结构简单,具有实际应用价值。     

多波长激光扩束器的光学设计

在激光雷达以及光谱仪定标时常常需要较宽以及高准直性的激光光束。设计了一出射光束为16mm,扩束比为20倍的激光扩束器光学系统。通过移动激光扩束器的物镜与目镜间隔,可以实现光谱范围在543.5~850nm的激光扩束;比较了使用该激光扩束器发射的准直激光束与理想的单色平行光充满成像光谱仪的入瞳孔径后成像光谱仪传递函数的变化,说明该光学系统可行。     

分体式激光扩束系统平行度测量装置的设计

为精确测量强激光发射系统中高功率激光经分体式扩束系统后光束的传输方向,设计了一种新型分体式扩束系统输出光平行度测量装置.根据高功率激光分体式扩束系统及红外激光的特点,该装置采用高分辨率红外CCD作为监测成像设备.采用轻质高刚度的优质铝合金对装置的机械结构进行了设计,切换部件搭载在高精度线性位移平台上.基于高分辨率CCD和精密线性位移平台,该装置可较好地完成动态和静态测量.测试结果表明,该平行度测量装置工作稳定、可靠,测量精度优于2.0″;装置设计合理,实用,可为扩束系统的装调及应用提供可靠依据.     

微束衍射仪中的光束准直技术

本文介绍X射线衍射仪中微束衍射仪(MDG)的光束准直技术。对准直的概念及各调节机构在光束准直中的功能进行了分析。提出一种简单快速的光束准直方法。     

LD准直透镜光能耦合效率与波差的理论分析

ＬＤ准直透镜光能耦合效率与波差的理论分析陈海清，阮玉，常洋燕（华中理工大学）０引言激光二级管发射的光束是发散的，需经过椭圆光束准直，整形及象散校正，从而获得发散度小准直度高的光束，同时还要考虑系统的光能利用效率与波差问题。准直透镜的作用是把ＬＤ所发出...     

电子束泵浦准分子激光放大器的双程光路自动准直

提出了一种电子束泵浦准分子激光放大器的双程光路准直方法,以保证光束在放大器中按照预定方向传输,并使多路光束稳定精确地照射靶面.首先,鉴于准分子放大器中无天然准直基准提出了利用双叉丝像传递光路进行准直的方法,即把输入光束叉丝基准作为“近场点”,把输出光束叉丝基准作为“远场点”,并设计了放大器准直光路,编写了相应的软件.然后,在现有实验室条件下开展了电子束泵浦准分子激光放大器双程光路的自动准直实验.最后,分析了影响该方法的相关因素及准直精度.实验及分析表明,设计的准直系统在较短时间内实现了预定传输光路的自动准直,系统自身精度为0.63μrad,光束最大复位误差为13.75 μm,满足了电子束泵浦准分子激光放大器双程光路自动准直的要求.     

CCD分段测量的光学位移测量系统

为了高精度地实现大量程的位移测量,采用传统激光三角法的测量原理,提出一种基于虚拟探测器的激光三角法来测量位移。该方法基于3个CCD分段测量的思想,将3个CCD互相独立且沿光轴均匀分布,以此扩大传统方法测量的范围。使用平面反射镜作为虚拟探测器进行探测,当成像光束经平面镜反射后在CCD上成像时,系统相当于增加了一个CCD,扩展了测量量程。由准直系统、偏振片、光阑组成准直滤光系统,缩小探测器光敏面上像点的直径,减小被测表面非理想光点对测量精度的影响,从而实现了较高精度下的大位移测量。最后通过实验验证了方法的可行性。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.