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liDAR点云与影像相结合的建筑物轮廓信息提取

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国土资源遥感 2014年第2期26卷 54-59页

作者：李云帆龚威平林俞先汪波住房和城乡建设部城乡规划管理中心北京100835

分析机载liDAR点云与影像数据特点,提出了一种建筑物点云与配准后影像相结合的建筑物轮廓信息提取方法。首先,采用α-shapes算法从点云中提取粗糙的建筑物轮廓多边形;然后,采用基于线支撑区域的直线段提取算法从影像中提取边缘信息,并... 详细信息

分析机载liDAR点云与影像数据特点,提出了一种建筑物点云与配准后影像相结合的建筑物轮廓信息提取方法。首先,采用α-shapes算法从点云中提取粗糙的建筑物轮廓多边形;然后,采用基于线支撑区域的直线段提取算法从影像中提取边缘信息,并利用投票机制,以点到直线的距离为因子,从中过滤出真实的建筑物边界;最后,提出一种建筑物轮廓精化的新方法,利用从影像中提取的边缘信息修正从点云中提取的粗糙轮廓,并对修正后的轮廓采用道格拉斯-普克算法去除冗余节点,采用强制相交方法恢复建筑物转角,最终得到了准确的建筑物外轮廓多边形,并通过实验验证了该方法的有效性。

关键词： liDAR 点云航空影像建筑物轮廓提取

低压脉冲磁场对2024铝合金凝固组织的细化

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特种铸造及有色合金 2012年第12期32卷 1168-1171页

作者：袁秀妹左志立王图宏李运凡张磊南昌航空大学航空制造工程学院

在2024铝合金的凝固过程中施加低压脉冲磁场处理,研究了低压脉冲磁场作用下2024铝合金凝固组织的变化,考察了浇注温度和放电电压对2024铝合金凝固组织中α-Al相形貌和尺寸的影响。结果表明,在低压脉冲磁场的作用下,2024铝合金凝固组织... 详细信息

在2024铝合金的凝固过程中施加低压脉冲磁场处理,研究了低压脉冲磁场作用下2024铝合金凝固组织的变化,考察了浇注温度和放电电压对2024铝合金凝固组织中α-Al相形貌和尺寸的影响。结果表明,在低压脉冲磁场的作用下,2024铝合金凝固组织中的初生α-Al相和共晶组织均显著细化。浇注温度越接近液相线温度,初生α-Al的平均晶粒尺寸越小。随着放电电压的升高,初生α-Al的平均晶粒尺寸逐渐减小,当放电电压为250V时,平均晶粒尺寸达到最小值。

关键词：低压脉冲磁场 2024铝合金凝固组织浇注温度放电电压细化

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基于单目视觉的机器人定位算法

机电工程技术 2024年第5期53卷 159-161,166页

作者：张云凡江励徐俊佳汤健华五邑大学智能制造学部广东江门529000

目前用于单目视觉测量所采用的ArUco标定方法精度较低,无法满足高精度的定位和测距应用。提出了一种基于单目视觉的机器人定位算法,在原始标记周围使用额外的矩形图案进行增强,使其形成一个棋盘格的形状,并引入亚像素角点计算方法,精准... 详细信息

目前用于单目视觉测量所采用的ArUco标定方法精度较低,无法满足高精度的定位和测距应用。提出了一种基于单目视觉的机器人定位算法,在原始标记周围使用额外的矩形图案进行增强,使其形成一个棋盘格的形状,并引入亚像素角点计算方法,精准定位标记角点坐标信息。最后,通过使用最小二乘法进行拟合,使用PnP算法计算相机相对于标记的空间位置信息,有效提高姿态估计和测距精度。测试结果表明,所提定位方法将深度方向提高了5 mm,误差仅为2 mm左右,相较现有的方法深度估计误差减小了66.7%,水平方向误差仅为1 mm。在复杂环境以及在部分遮挡的ArUco标记也能准确无误的识别。

关键词：机器视觉 ArUco标记 PnP算法优化算法鲁棒性

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郭濬《增定评注唐诗正声》体例及其“平调”观述论

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绵阳师范学院学报 2024年第1期43卷 137-146页

作者：郑永辉付云帆闽南师范大学闽南文化研究院福建漳州363000

明末郭濬所编的《增定评注唐诗正声》,参考了唐汝询《汇集唐诗十集》合编明代具有影响力的唐诗选集的做法,将高棅《唐诗品汇》、李攀龙《唐诗选》两种唐诗选本用新的体例进行合编,且将李《选》独选的篇目及郭濬自认为属于唐诗“正声”... 详细信息

明末郭濬所编的《增定评注唐诗正声》,参考了唐汝询《汇集唐诗十集》合编明代具有影响力的唐诗选集的做法,将高棅《唐诗品汇》、李攀龙《唐诗选》两种唐诗选本用新的体例进行合编,且将李《选》独选的篇目及郭濬自认为属于唐诗“正声”而高、李二人漏选的篇目增入。注释及评语方面,高棅《唐诗正声》原编收录评语计27家,以唐宋间最多。而郭濬本精选评语23家,以明代评语最多,高氏所收评语大多汰去。此外,郭濬又将高、李两种选本中属于“平调”的诗作别编为附录,附于每卷之后。选诗的增删和评语的辑选,体现了郭氏作为晚明唐诗选家有别于明代前期以高棅、李攀龙为代表的审美标准。

关键词：《唐诗正声》唐诗选本郭濬 “平调”观

一锅溶热法制备适合超级电容器电极的改性NiCo_(2)S_(4)@C材料

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电工材料 2024年第2期 20-22,25页

作者：汪博路云帆李小兰张立磊南华大学化学化工学院湖南衡阳421001

为了使硫化镍钴(NiCo_(2)S_(4))作为超级电容器电极材料获得更高的倍率性能和循环稳定性,添加葡萄糖,通过水热法在核心NiCo_(2)S_(4)上涂覆导电碳层,制备NiCo_(2)S_(4)@C。碳层可以防止NiCo_(2)S_(4)聚集,形成更多的微孔,从而形成相对... 详细信息

为了使硫化镍钴(NiCo_(2)S_(4))作为超级电容器电极材料获得更高的倍率性能和循环稳定性,添加葡萄糖,通过水热法在核心NiCo_(2)S_(4)上涂覆导电碳层,制备NiCo_(2)S_(4)@C。碳层可以防止NiCo_(2)S_(4)聚集,形成更多的微孔,从而形成相对较大的比表面积。所制备的NiCo_(2)S_(4)@C显示出较好的倍率性能,在1 Ag^(-1)时的比电容为1587.8 Fg^(-1),最高可达1162.5 Fg^(-1)(10 Ag^(-1))。此外,其容量保持率在2000次循环后高达96.2%。

关键词： NiCo_(2)S_(4) 倍率性能循环稳定性超级电容器涂层碳

Synthesis of high-purity mesoporous nanosilica microspheres from retired composite insulators based on orthogonal experiment

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High Voltage 2022年第6期7卷 1111-1122页

作者： Rongxin Chen li Cheng yunfan liu liang Yu Ruijin liao Tingting Wang School of Electrical Engineering Chongqing UniversityChongqingChina State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing UniversityChongqingChina Electric Power Research Institute of China Southern Power Grid GuangzhouGuangdong ProvinceChina

Silicone rubber is an indispensable insulation material for power equipment and is difficult to degrade naturally,posing a serious threat to the *** remains challenging to dispose this alarming amount of *** our previous research,a green pyrolysis recycling method was proposed for waste composite *** this article,the experimental device was further improved,and the recycling process was optimised by orthogonal experiments to obtain nanosilica microspheres(NSMs)with higher purity and controllable particle size for the state-of-the-art engineering ***,the effect of three factors(calcination temperature,constant-temperature duration,and heating rate)on the particle size of NSMs were investigated by single-factor *** and response analyses were then used to examine the goodness of fit of the multi-parameter fitting equation and the interaction impact of multiple factors on the particle ***,homogeneous mesoporous NSMs with higher purity(increased from 97%to 99%)and smaller particle size(decreased from 160 to 103 nm were prepared under the guidance of *** SiO_(2)-recovery rate of this method was 74.7%,revealing superior economic value.

关键词： purity silica insulator

节水减氮和品种管理对双季稻CH_(4)的减排效果

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生态学杂志 2024年第3期43卷 724-732页

作者：宋春燕李玉娥万运帆秦晓波张欣禹朱波胡严炎王斌中国农业科学院农业环境与可持续发展研究所/农业农村部农业环境重点实验室北京100081 中化现代农业有限公司北京100031 长江大学农学院湖北荆州434022

秸秆还田、高效肥料、节水减氮是我国农业绿色发展主推技术,高产低排放品种是减少稻田CH_(4)排放重要方向。为明确秸秆还田下氮肥减量及节水灌溉集成技术对不同品种水稻田CH_(4)排放的影响,本研究以双季稻为对象,采用随机区组的裂区试... 详细信息

秸秆还田、高效肥料、节水减氮是我国农业绿色发展主推技术,高产低排放品种是减少稻田CH_(4)排放重要方向。为明确秸秆还田下氮肥减量及节水灌溉集成技术对不同品种水稻田CH_(4)排放的影响,本研究以双季稻为对象,采用随机区组的裂区试验设计,设置施用尿素+间歇灌溉(U)、尿素减量20%+秸秆还田+间歇灌溉(US+S)、控释尿素减量20%+秸秆还田+间歇灌溉(CRUS+S)、尿素减量20%+秸秆还田+节水灌溉(US+S+SWD)共4个主区因素,常规稻和杂交稻作为2个副区因素,利用静态箱-气相色谱法监测双季稻生育期内CH_(4)排放规律及减排效果。结果表明,碳投入、氮投入、灌溉量和分蘖数是影响双季稻CH_(4)排放的主要因素。秸秆还田可补充氮肥20%减量的养分,并显著促进常规稻和杂交稻CH_(4)的排放,其中常规稻增排60.0%~107.8%,杂交稻增排99.8%~107.8%,这主要归结于秸秆还田带来大量碳源。秸秆还田搭配控释尿素并不能减少CH_(4)排放,较US+S增排1.8%~9.7%(除常规晚稻外)。节水灌溉能显著控制秸秆还田下CH_(4)排放的大量增长,相比US+S,US+S+SWD处理显著降低了CH_(4)排放15.9%~23.1%。各处理间产量无显著差异,表明秸秆还田下氮肥减量及节水灌溉可以达到稳产作用。杂交稻CH_(4)排放量及产量略高于常规稻,但不存在显著差异。总体而言,秸秆还田显著提高CH_(4)排放量,控释尿素和减量施氮无明显减排效果,节水灌溉能有效降低秸秆还田下单位产量的CH_(4)排放强度。未来随着稻田秸秆还田比例增加,优化水分管理以促进秸秆好氧分解将成为CH_(4)减排的关键。

关键词： CH_(4) 秸秆还田氮肥减量控释尿素节水灌溉水稻

Considering time-lag effects can improve the accuracy of NPP simulation using a light use efficiency model

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Journal of Geographical Sciences 2023年第5期33卷 961-979页

作者： li Chuanhua liU yunfan ZHU Tongbin ZHOU Min DOU Tianbao liU lihui WU Xiaodong College of Geography and Environmental Science Northwest Normal UniversityKey Laboratory of Resource Environment and Sustainable Development of OasisLanzhou730070China Cryosphere Research Station on the Qinghai-Tibet Plateau State Key Laboratory of Cryospheric ScienceNorthwest Institute of Eco-Environment and ResourcesCASLanzhou730000China

Most terrestrial models synchronously calculate net primary productivity(NPP)using the input climate variable,without the consideration of time-lag effects,which may increase the uncertainty of NPP *** on Normalized Difference Vegetation Index(NDVI)and climate data,we used the time lag cross-correlation method to investigate the time-lag effects of temperature,precipitation,and solar radiation in different seasons on NDVI ***,we selected the Carnegie-Ames-Stanford approach(CASA)model to estimate the NPP of China from 2002 to *** results showed that the response of vegetation growth to climate factors had an obvious lag effect,with the longest time lag in solar radiation and the shortest time lag in *** time lag of vegetation to the climate variable showed great tempo-spatial heterogeneities among vegetation types,climate types,and vegetation growth *** on the validation using eddy covariance data,the results showed that the simulation accuracy of the CASA model considering the time-lag effects was effectively *** considering the time-lag effects,the average total amount of NPP modeled by CASA during 2001-2017 in China was 3.977 PgC a^(−1),which is 11.37%higher than that of the original *** study highlights the importance of considering the time lag for the simulation of vegetation growth,and provides a useful tool for the improvement of the vegetation productivity model.

关键词： net primary productivity(NPP) time-lag effects CASA model climate change

A deep-learning-based workflow to deal with the defocusing problem in high-throughput experiments

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Bioactive Materials 2022年第5期7卷 218-229页

作者： yunfan Xue Honglin Qian Xu li Jing Wang Kefeng Ren Jian Ji MOE Key Laboratory of Macromolecule Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou310027PR China

The increasing throughput of experiments in biomaterials research makes automatic techniques more and more *** all the characterization methods,microscopy makes fundamental contributions to biomaterials science where precisely focused images are the basis of related *** automatic focusing has been widely applied in all kinds of microscopes,defocused images can still be acquired now and then due to factors including background noises of materials and mechanical ***,we present a deep-learning-based method for the automatic sorting and reconstruction of defocused cell ***,the defocusing problem is illustrated on a high-throughput cell ***,a comprehensive dataset of phase-contrast images captured from varied conditions containing multiple cell types,magnifications,and substrate materials is prepared to establish and test our *** obtain high accuracy of over 0.993 on the dataset using a simple network architecture that requires less than half of the training time compared with the classical ResNetV2 ***,the subcellular-level reconstruction of heavily defocused cell images is achieved with another *** applicability of the established workflow in practice is finally demonstrated on the high-throughput cell *** intelligent workflow does not require a priori knowledge of focusing algorithms,possessing widespread application value in cell experiments concerning high-throughput or time-lapse imaging.

关键词： High-throughput Deep learning Cell imaging Refocusing Microscopy