基于Civil 3D计算水库库容的方法研究

在Civil 3D中以地形曲面为"基准曲面",水位曲面为"对照曲面",应用体积面板快速统计出相应库容,便于绘制水位-库容曲线。相对于传统算法,此方法能消除面积量测误差,结果的准确度只取决于地形图精度,尤其对于多孤岛情况效率优势明显,具有实际的应用价值。     

两种沥青胶浆的疲劳及自愈合性能试验

为了研究沥青胶浆的疲劳及自愈合特性,利用动态剪切流变仪（DSR）进行时间扫描及疲劳-愈合-再疲劳测试,并通过原子力显微镜（AFM）对细观结构进行观测,比较分析了不同粉胶比下基质沥青胶浆和苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）改性沥青胶浆的疲劳性能,以及在常温（25℃）下3个不同间歇期的自愈合性能。试验发现：SBS沥青胶浆具有更好的疲劳和自愈合性能,两种沥青胶浆疲劳寿命均随粉胶比的增大而增加,同一粉胶比条件下,更长的间歇期有利于其自愈合,过大或者过小的粉胶比都会降低沥青胶浆的自愈合性能;AFM观测结果表明：基质沥青胶浆出现明显的"蜂状结构",粉胶比增加,矿粉吸附更多的沥青质,"蜂状结构"变多,与沥青界面内聚力作用增强,提高了抗疲劳性能,SBS改性剂与沥青相容性良好,改性沥青胶浆没有出现"蜂状结构",改性剂的加入增强了分子间内聚力,有助于提高抗疲劳性能,因此建议路面材料选用改性沥青胶浆。     

热老化后SBS改性沥青的微观结构及自愈合性能EI北大核心CSCD

采用动态剪切流变仪(DSR)和原子力显微镜(AFM),分别对原样沥青、经旋转薄膜烘箱(RTFO)老化后和压力老化(PAV)后的SBS改性沥青进行测试,分析SBS改性沥青在不同老化程度、损伤程度、自愈时间和自愈温度等因素的影响下,其自愈合性能的变化规律。通过四因素三水平的正交实验,得到影响SBS沥青自愈合能力的最大因素;利用原子力显微镜观测不同老化程度下SBS改性沥青的微观结构。结果表明,影响沥青自愈合性能的最大因素是老化程度,其后依次是损伤程度、愈合温度和愈合时间;综合原子力显微镜的观测结果,沥青经老化作用后表面越粗糙,其自愈性也就越差。     

A lattice measuring method based on integral imaging technology

Aiming at the problem that the lattice feature exceeds the view field of the scanning electron microscope (SEM) measuring system, a new lattice measuring method is proposed based on integral imaging technology. When the system works, the SEM measuring system is equivalent to an integral image acquisition system. Firstly, a lattice measuring method is researched based on integral imaging theory. Secondly, the system parameters are calibrated by the VLSI lattice standard. Finally, the value of the lattice standard to be tested is determined based on the calibration parameters and the lattice measuring algorithm. The experimental results show that, compared with the traditional electron microscope measurement method, the relative error of the measured value of the algorithm is maintained within 0.2%, with the same level of measurement accuracy, but it expands the field of view of the electron microscope measurement system, which is suitable for the measurement of samples under high magnification.     

一种新的GPS空时抗干扰方案

为了解决GPS子空间跟踪抗干扰的干扰维数估计问题,通过分析FAPI子空间跟踪算法,并讨论干扰维数的估计对算法性能的影响,利用GPS抗干扰的特殊性,提出基于部分协方差阵特征值分解的GPS"有效"干扰个数估计方法,并联合FAPI算法和本文提出方法,得到一种新型空时GPS子空间抗干扰方案.仿真结果表明"有效"干扰个数可以被实...     

基于残迹融合的高可用分布式导航算法

导航通信中断等问题经常导致电子地图中的自动寻路功能失效.为了实现分布式导航系统的有效容灾和寻路优化,提出了基于道路残迹数据融合的高可用分布式导航算法;给出了该算法的主要思想、算法模型、数据结构以及运行流程.该算法应用了蒙特卡罗方法进行道路可通行度评估;采用了2维叠加空间进行"道路信息-寻路需求"匹配方法.最后进行了算法效能分析与仿真.仿真实验结果证明,该算法具有较好的容灾性能、响应速度和较好的适应能力.     

Subpixel Reconstruction Algorithm in Staring FPA Nonuniform Microscan Imaging

For the nonuniform microscan system where the interframe translation is no longer equivalent to accurate halfpixel, a 2-dimension non-interpolated subpixel algorithm is proposed to consider arbitrary value of microscanning. The aim of the proposed algorithm is to restore double resolution from 2×2 undersampled frames. To solve the ill-posed problem in the process of image reconstruction, the prior boundary condition is introduced, and the proposed subpixel reconstruction algorithm is reformulated into the form of line-by-line backward propagation iteration for reducing the calculation complexity. Since the direction of movement offset relative to the accurate halfpixel determines the transfer matrix of the image degradation process, the reconstruction is classified into 4 types when 2×2 microscan model is applied. All the simulation results and experiment data demonstrate the double resolution improvement compared with the undersampled images. The focus problem, scarcely any possibility of the operation with accurate halfpixel micromotion, is figured out for enhancing the feasibility of subpixel reconstruction used in practice.     

一种适用于工程实测的集成式PM_(2.5)采样枪研制

针对进口枪头尺寸大、结构复杂、成本高、易损坏等问题,自制了一套适用于国内工程实测的集成式PM_(2.5)采样枪。经性能对比,自制枪的温控能力不输进口枪,且安全稳定性能更优。经现场实测数据显示,进口枪和自制枪所采集数据非常接近。自制PM_(2.5)采样枪可满足现场PM_(2.5)实测要求,且成本不到进口枪的1/10。     

光电导开关中的隧穿现象

采用光刻和大气环境下原子力显微镜(AFM)阳极诱导氧化加工相结合的加工方法,加工由Ti-TiOx-Ti纳米级隧道结构成其基本结构的微型光电导开关(PCSS),并对其电特性进行了研究和分析.研究结果表明在大气室温条件下,微型PC-SS的输出特性随氧化物宽度不同而不同,当宽度小于100 nm时,其输出特性表现为在一个线性峰值的输出过后,又出现了一个非线性的峰值;在一定条件下Ti-TiOx-Ti纳米级隧道结存在隧穿效应,且其隧穿特性随绝缘金属氧化物的宽度不同而不同.     

Cr3 C2含量对Cr3 C2/Ni3 Al复合材料摩擦磨损性能的影响

采用热等静压法制备Ni₃Al合金和Cr₃C₂含量不同的Ni₃Al基复合耐磨材料,利用扫描电镜、能谱仪、X射线衍射仪及摩擦磨损试验机,系统地研究Cr₃C₂含量对材料组织特征、硬度及摩擦磨损性能的影响.结果表明:Cr₃C₂/Ni₃Al复合材料中,Cr₃C₂颗粒与Ni₃Al颗粒之间发生互扩散作用,使部分Cr₃C₂颗粒转变为M₇C₃（M=Cr,Fe,Ni）结构;在特定的摩擦磨损条件下,随着Ni₃Al基体中Cr₃C₂比例增大,Cr₃C₂/Ni₃Al复合材料的耐磨性能显著提高,达到了Ni₃Al合金耐磨性能的4~10倍.此外,随着Ni₃Al基体中Cr₃C₂比例的增大,Cr₃C₂/Ni₃Al复合材料对对磨盘的切削、刮擦作用减弱,对磨盘的磨损量减少.