Synthesis of Polyfluorene-Polytriarylamine Block Copolymer with Emitting Part at Junction Point for Light Emitting Applications

A block copolymer consisting of polyfluorene (PF) and polytriarylamine (PTAA) functionalized with green emitting phenoxazine moiety at the junction point of two blocks was designed and prepared for electroluminescent application. PF homopolymer was synthesized by Suzuki coupling polymerization, and was reacted with brominated phenoxazine. In the presence of the resulting PF functionalized with phenoxazine, C-N coupling polymerization of 4-(4’-bromophenyl)-4’’-butyldiphenylamine was carried out to afford a triblock copolymer, PTAA-phenoxazine-PF-phenoxazine-PTAA (PF-Ph-PTAA). Two types of random copolymers were also synthesized with fluorene and phenoxazine (PF2) by Suzuki coupling polymerization for comparison. All the polymers were soluble in common organic solvents and readily formed thin films by a solution processing. Prepared polymers exhibited similar UV absorption and PL emission in chloroform solutions. In a film state, the existence of phenoxazine unit drastically changed PL spectra. Although the content of phenoxazine unit in PF-Ph-PTAA was relatively high (13 mol%), it showed similar PL spectrum to that of PF2(phenoxazine content, 0.2 mol%) indicating that phenoxazine unit is isolated in single polymer chain nevertheless the high content. EL device based on PF-Ph-PTAA showed green-emission, suggesting that emission sites predominantly located in the vicinity of phenoxazine moiety because of its shallow HOMO level.

Temperature Effect on Light Concentration Silicon Solar Cell’s Operating Point and Conversion Efficiency

It is well known that temperature acts negatively on practically all the parameters of photovoltaic solar cells. Also, the solar cells which are subjected to particularly very high temperatures are the light concentration solar cells and are used in light concentration photovoltaic systems (CPV). In fact, the significant heating of these solar cells is due to the concentration of the solar flux which arrives on them. Light concentration solar cells appear as solar cells under strong influences of heating and temperature. It is therefore necessary to take into account temperature effect on light concentration solar cells performances in order to obtain realistic results. This one-dimensional study of a crystalline silicon solar cell under light concentration takes into account electrons concentration gradient electric field in the determination of the continuity equation of minority carriers in the base. To determine excess minority carrier’s density, the effects of temperature on the diffusion and mobility of electrons and holes, on the intrinsic concentration of electrons, on carrier’s generation rate as well as on width of band gap have also been taken into account. The results show that an increase of temperature improves diffusion parameters and leads to an increase of the short-circuit photocurrent density. However, an increase of temperature leads to a significant decrease in open-circuit photovoltage, maximum electric power and conversion efficiency. The results also show that the operating point and the maximum power point (MPP) moves to the open circuit when the cell temperature increases.

28例轻嵴帽的Null Point临床特征分析

目的:分析轻嵴帽患者眼震消失平面(NP)的临床特征。方法:纳入仰卧滚转试验表现为持续性向地性变向性位置性眼震且有NP的患者28例;在眼震视图下行观察其动态位置性眼震特征,并寻找NP进行定侧诊断;给予手法复位,并于首次复位后1周及1个月随访,观察患者的转归。结果:28例轻嵴帽患者中,11例(39.3%)有自发眼震;10例(35.7%)有NP1,28例(100%)有NP2和NP3,且患者对NP2检测时的耐受性较好;首次复位有效率为7.1%,1周随访有效率为14.3%,1月随访有效率100%。结论:NP2检测是轻嵴帽诊断及定侧诊断的简便、可行的方法;轻嵴帽患者复位效果差,但病程多呈自限性。

基于LightGBM的乘客候车路段推荐方法

目前城市出租车服务系统中出租车的营运效率普遍不高,一方面出租车有较高的空载率,另一方面由于乘客盲目选择打车地点而造成打车难的问题。针对上述问题,提出了一种基于LightGBM的乘客候车路段推荐方法。该方法从城市出租车的历史轨迹信息中提取影响空载的时空特征,利用LightGBM框架预测各个路段出租车的空载数量,并以此计算各个路段在未来一个时隙内成功打到空车的概率,最终根据乘客所处位置将其附近成功打车概率最高的路段推荐给乘客。仿真实验利用了西安市出租车数据对模型进行训练和验证,并将实验效果与SVR、GBDT等方法进行了对比。实验结果表明,所提方法的RMSE、MAE、MAPE等指标均优于其他方法,该模型对解决出租车与乘客人车矛盾有一定实用价值。

基于Silverlight网页游戏的寻径优化算法

为了解决A*路径搜索算法在Silverlight网页游戏中的搜索费时和路径曲折等问题,在结合光线跨越算法和引入父结点指针的二叉堆存储开启列表的A*算法的基础上,提出了一种基于Silverlight网页游戏的寻径优化算法。该算法在现有研究的基础上使用光线跨越算法减小A*算法搜索规模,同时将动态关键点技术与光线跨越算法结合来优化算法返回的路径。将该算法在游戏所使用的网格地图中进行实验,实验结果表明,该算法能够有效地根据系统设定的通行条件寻找出一条最优的实际可行的路径,同时缩短寻路的时间消耗和所寻的路径长度,提高游戏的可玩性。

Optical Design and Stray Light Analysis of the Space Infrared Optical System

This article describes a novel configuration design for a re-imaging off-axis catadioptric space infrared optical system,and in order to satisfy the signal noise ratio requirements of the system,the stray light of the system is necessary to analyze and restrain. The optical system with a focal length of 1 200 mm,an entrance pupil diameter of 600 mm,an F-number of 2,a field of view of 3°× 0. 15°,a working wave band of 8 μm-10 μm,and the image quality of the optical system almost approach to diffraction limits in all field of view.Then the mathematical models of stray light are built,and the suppressive structure is established to eliminate the effect of stray light. Finally,TraceP ro is used to analyze and simulate stray light with and without the suppressive structure,and also get the results of the PST curves. The results indicate that appropriate optical system and suppressive structure can highly reduce the stray light of the space infrared optical system.

Effects of Low Temperature and Poor Light Environments under LED Lighting on Quality Change of Pepper Seedlings during Storage

Storage and transportation of vegetable commercial seedlings becomes an important link along with the continuous expansion of planting areas of facility vegetables and vegetable seedling culture industry. In this study,pepper variety‘Nongda 24' was as the experimental material,and changes in the morphological and physiological indicators of plug seedlings in different low temperature( 6 and 11℃) and poor light environments were studied to find suitable storage environmental conditions. The results showed that pepper seedlings could be stored and transported for 14 days when storage temperature was 11℃ and light conditions such as light intensity and photoperiod were 30 μmol/( m^2·s)and 12 h/d by using a fluorescent lamp with R∶ B ratio of 1. 9,and 15 μmol/( m^2·s) and 24 h/d by using LED with R∶ B ratio of 1. 3,respectively. Moreover,the quality of pepper seedlings could be protected effectively. Compared to the fluorescent lamp,LED with high luminous efficiency and low energy consumption was suitable for the storage or long-distance transportation of pepper seedlings in low temperature and poor light environments.

基于线结构光扫描的工件高精度三维测量方法

为了提高工业中对复杂轮廓工件的测量精度和效率,设计了一套高精度非接触三维测量系统,并提出了一种基于线结构光扫描的工件轮廓三维测量方法。首先,利用高精度相机和三轴移动平台采集线结构光图像。然后,通过基于差分区间的灰度质心算法,精确而高效地提取出线结构光中心线,并生成原始点云模型。接着,对采集到的点云数据进行必要的点云滤波和精简预处理。最后,将预处理后的点云数据与CAD模型精确配准,进行工件表面轮廓的测量与误差评定。实验结果表明:测量工件轮廓高度的绝对误差小于0.07 mm,相对误差小于0.5%。所提出的三维测量系统及方法测量误差较低,能够实现工件的高精度三维测量,具有一定的工业应用价值。

基于改进自适应阈值及四叉树的ORB_SLAM3算法研究

针对ORB-SLAM3(Oriented Fast and Rotated Brief Simultaneous Localization and Mapping)在外界光照条件变化时算法检测的特征点数量急剧减少且分布过于集中的问题,文章提出一种基于改进自适应阈值及四叉树的ORB_SLAM3算法。该方法首先通过计算特征点周围像素灰度值与平均灰度值的方差获得环境对比度;其次通过对比度计算光照自适应阈值;最后通过优化四叉树方法管理特征点,使图像中特征点的分布更加均匀。实验结果显示,正常光照强度条件下的特征点数量增加了9.5%、特征点均匀度提高了88.3%;低光照强度条件下的特征点数量增加了30.4%、特征点均匀度提高了34.0%;高光照强度条件下的特征点数量增加了72.9%、特征点均匀度提高了37.8%。以上说明该改进算法在视觉导航中具有较高的应用价值。

不同物料流对皮带机转载点的振动冲击分析与研究

选煤厂带式输送机转载点处两皮带有一定高度差,受上端面煤块大小、含水量等因素影响,会对皮带机造成不同程度的振动冲击,从而影响皮带机带身及托辊的使用寿命。为探究物料流对转载点振动冲击的影响,结合现场调研及相关理论,推出落料冲击的影响因素主要为物料流粒度级别和含水量。然后利用光纤振动传感器、数据采集卡等器材和Labview测试系统进行现场试验,将落料口下方带式输送机在不同物料流冲击下的振动信号进行采集和处理,试验结果表明,不同粒度物料流对转载点振动冲击不同,小粒度物料流对转载点的振动波形峰值为大粒度物料流的20%,自功率谱波形峰值为0.625%;不同含水量对转载点振动冲击不同,含水量少的物料流对转载点的振动波形峰值为含水量多物料流的60%,自功率谱波形峰值降低为45%。研究结果可为降低皮带机转载点振动冲击提供合理的方法。

用分光计测三棱镜折射率光路图的MATLAB动画演示

建立了三棱镜光路图的数学模型,应用MATLAB绘制光路图,检验了模型的正确性.随着三棱镜的旋转,直观地演示了分光计中光路图和偏向角的变化过程,指出了最小偏向角.

Research and Application of Caideng Model Rendering Technology for Virtual Reality

With the development of virtual reality (VR) technology, more and more industries are beginning to integrate with VR technology. In response to the problem of not being able to directly render the lighting effect of Caideng in digital Caideng scenes, this article analyzes the lighting model. It combines it with the lighting effect of Caideng scenes to design an optimized lighting model algorithm that fuses the bidirectional transmission distribution function (BTDF) model. This algorithm can efficiently render the lighting effect of Caideng models in a virtual environment. And using image optimization processing methods, the immersive experience effect on the VR is enhanced. Finally, a Caideng roaming interactive system was designed based on this method. The results show that the frame rate of the system is stable during operation, maintained above 60 fps, and has a good immersive experience.

基于多点结构光扫描的工件定位方法

在自动化生产线工业机器人抓取工件作业中,工件定位方法直接影响作业质量、效率及系统成本。传统基于线结构光的工件定位方式通常存在专用性强、成本高等特点,难以在劳动密集型产业中推广应用。针对这一问题,利用KD-tree ICP算法,提出一种基于多点结构光扫描的工业机器人抓取工件定位方法。首先,利用模型点云和多点结构光原始点云进行粗配准;其次,提取待定位工件点云特征点,并拟合出工件边界;最后,利用模型边界点云和拟合出工件边界点云进行精配准。试验结果表明,该方法具有较高的定位精度及识别效率,满足工件抓取要求。

八髎穴齐刺联合红外偏振光治疗急性非特异性下腰痛临床研究

目的:观察八髎穴齐刺联合红外偏振光照射治疗急性非特异性下腰痛的临床疗效。方法:60例急性非特异性下腰痛患者随机分为观察组和对照组,每组各30例。两组患者均使用红外偏振光采用振荡模式照射针刺部位,1次/d;对照组采用常规针刺治疗,观察组采用八髎穴齐刺法针刺治疗,两组均治疗5 d。观察两组的临床疗效,比较两组治疗前后采用视觉模拟评分法(VAS)评价腰腿部疼痛程度,采用Oswestry功能障碍指数(ODI)评价腰椎功能,采用指地距离(FFD)评价腰部主动前屈受限程度,采用健康状况调查问卷SF-36在治疗前后评价患者的生活质量。结果:与治疗前比较,两组VAS评分、ODI评分和FFD评分均明显下降,差异有统计学意义(P<0.05),且观察组评分降低值均显著大于对照组,差异有统计学意义(P<0.05);与治疗前比较,两组SF-36评分明显提高,差异有统计学意义(P<0.05),且观察组评分明显高于对照组,差异有统计学意义(P<0.05)。观察组总有效率为96.67%(29/30),显著高于对照组的80.00%(24/30),两组差异有统计学意义(P<0.05)。两组均未出现明显不良反应。结论:以八髎穴齐刺针刺法联合红外偏振光照射治疗急性非特异性下腰痛疗效显著,在缓解患者疼痛及改善腰部前屈活动方面效果优于常规针刺方式,改善患者生活质量早期疗效明显。

基于深度学习的机载点云屋顶平面提取算法

为了准确提取不同类型建筑物屋顶点云的各个平面,采用度量学习的方式,将每个平面视为单独的实例,为每个平面上的点学习单独的高维深度特征。利用所提取的高维深度特征对平面点进行初步的聚类,通过简单的欧氏距离和特征空间距离进行综合度量将未聚类的点分配至各个平面;所提出的方法分别在合成数据集和公开的机载点云建筑物屋顶数据集RoofN3D上进行了训练和测试。结果表明,在合成数据集上,所提取的建筑物平面的准确率、召回率和F_(1)分数分别为0.990、0.998和0.994;在机载点云数据集RoofN3D上,所提取的建筑物平面的准确率、召回率和F_(1)分数分别为0.945、0.971和0.957。该方法不仅可以准确有效地提取出不同建筑物屋顶平面,且平面边缘非常准确,还可以准确区分建筑物屋顶平面内容和非平面内容,为建筑物3维建模提供重要帮助。

光笔视觉测量系统的精确测量研究

光笔视觉测量系统是以光笔为接触式辅助测量工具的一种便携式坐标测量系统,具有便携性好、测量范围大、精度高等优点。但在接触式测量过程中,记录的是测头中心坐标,需要对测头进行半径补偿。结合光笔式测量系统,提出一种针对散乱点云进行半径补偿的可行性方法。利用点云的网格化处理,寻找散乱点云中点的拓扑关系,得到局部点云的矩形拓扑网格。使用拓扑网格点进行NURBS曲面插值拟合,得到网格中心点的法向量。实验表明,该方法求得的法向量误差角度在0.5°左右,测头半径为2.5mm情况下,测量误差在0.030mm以下。

基于结构光的铆钉凹凸量双目视觉检测方法

为了弥补飞机铆钉凹凸量的传统检测方式在精度、效率及稳定性方面的不足,提出了一种基于结构光的铆钉凹凸量双目视觉检测方法。首先通过工业投影仪将结构光投射到铆接表面,由双目相机采集投影图像。然后根据铆钉边缘特征提取出铆接区域,并采用改进的格雷码解相位方法计算铆接区域表面的相位信息。根据相位信息匹配特征点,利用视差原理计算出点云。最后通过点云数据处理,计算出铆钉的凹凸量。制作标准件并完成了凹凸量测量试验,测量误差在±20μm以内,重复测量标准差小于3μm,单个铆钉测量用时约2.2 s,能够满足现场测量精度和效率要求。

松辽盆地白垩系青山口组一段页岩生、排烃组分特征及页岩油相态演化

松辽盆地白垩系青山口组一段(青一段)页岩有机质热演化程度跨度大、烃类流动性差异强。页岩油相态分析预测是页岩油勘探开发的重要难题。用低成熟页岩样品开展封闭体系及半封闭体系有机质热解实验,根据生、排烃组分特征对滞留烃的轻烃散失进行补偿校正,研究了页岩油组分演化特征。结合中央坳陷区主要生油凹陷典型井埋藏史、热演化史,研究了页岩油相态演化规律,提出了轻质页岩油勘探有利区和开发压力保护条件。研究结果表明:地质条件下随着有机质成熟度的升高,页岩油组分中轻质组分比例不断增加、气体逐渐增多,相包络线从高露点温度、低泡点压力依次向低露点温度、高泡点压力演化。齐家-古龙凹陷青一段页岩油在嫩江组中期油藏向挥发油油藏转化,长岭凹陷青一段页岩油从嫩江组末期开始油藏向挥发油油藏转化,三肇凹陷青一段页岩油则始终为黑油油藏。无论是黑油油藏还是挥发油油藏,均为单一液相。松辽盆地中央坳陷区青一段页岩油挥发油油藏主要分布在齐家-古龙凹陷中心和长岭凹陷北部有机质成熟度(镜质体反射率Ro)为1.3%~1.6%、地层压力为12.2~22.4 MPa的区域。

基于点云稀疏空间特征聚合激励的单阶段3D目标检测模型

针对目前基于点云的3D目标检测中单阶段体素法存在感受野固定、特征尺度单一,导致模型对点云特征学习不够充分、模型检测效果存在瓶颈等问题,提出了一种可端对端训练的基于体素的单阶段3D目标检测模型.首先,利用多尺度稀疏空间特征聚合模块,聚合点云在不同稀疏空间尺度上的特征,使特征充分保留点云的空间信息;然后,对特征进行分层激励,通过多尺度感受野对特征进行分层学习,强化特征的表达能力,降低噪声信息对检测结果的影响;最后,将特征输入检测头进行候选框的分类和回归.在公开的自动驾驶数据集KITTI上与主流单阶段3D目标检测模型进行了对比实验,包含对3类目标共9个的难度等级目标的检测.所提模型在其中5个等级中的平均准确率有明显提升,尤其对点云稀疏的目标,表现出较好的检测效果.实验结果表明,所提模型能够充分提取点云空间信息并有效地学习点云多尺度特征.

机载激光雷达点云数据地面滤波算法综述

机载激光雷达技术作为遥感信息获取领域的全新手段,因具有快速、准确获取地面三维坐标信息的特点,在地形测绘、环境监测、森林防护和城市三维建模等应用领域发挥着越来越显著的作用。地面滤波技术作为提取数字高程模型的核心环节,大量国内外学者对此做了许多专门的研究。本文在前人研究的基础上进行了系统性的梳理和总结,首先简要介绍了机载激光雷达系统的发展现状;随后探讨了地面滤波技术的发展历程,并对其进行了系统分类和梳理;最后,总结了当前地面滤波算法存在的不足之处,并展望了该领域未来的发展趋势。