期刊文献+
共找到38篇文章
< 1 2 >
每页显示 20 50 100
非均相Photo-Fenton反应中催化剂及其光催化机理研究进展 被引量:2
1
作者 刘杨先 《化学工业与工程技术》 CAS 2010年第5期18-23,共6页
非均相Photo-Fenton反应体系具有反应效率高、有效pH范围宽广以及催化剂可再生利用等优势,是一项极具发展潜力的新型高级氧化工艺。本文简单介绍了近几年来有关非均相Photo-Fenton体系中负载型光催化剂的最新研究成果,主要包括以SiO_2、... 非均相Photo-Fenton反应体系具有反应效率高、有效pH范围宽广以及催化剂可再生利用等优势,是一项极具发展潜力的新型高级氧化工艺。本文简单介绍了近几年来有关非均相Photo-Fenton体系中负载型光催化剂的最新研究成果,主要包括以SiO_2、Al_2O_3、分子筛、碳基材料、黏土材料等无机载体,以及以离子交换树脂和有机纤维材料等有机载体制备的负载型光催化剂,并且在此基础上着重讨论了光催化机理。对目前非均相Photo-Fenton反应存在的一些问题以及未来发展方向作了总结与展望。 展开更多
关键词 photo- Fenton(光-芬顿) 催化剂 反应机理 光催化
下载PDF
Wind Tunnel Test for Videogrammetric Deformation Measurement of UAV for Mars Airplane Balloon Experiment-1 (MABE-1) 被引量:1
2
作者 Koji Fujita Akira Oyama +2 位作者 Daisuke Kubo Masahiro Kanazaki Hiroki Nagai 《Journal of Flow Control, Measurement & Visualization》 2019年第2期87-100,共14页
This paper reports the results of the aerodynamic deformation measurements of the meter-scale, entire shape, actual UAV in the wind tunnel using a video grammetry technique. The measured airplane was the airplane for ... This paper reports the results of the aerodynamic deformation measurements of the meter-scale, entire shape, actual UAV in the wind tunnel using a video grammetry technique. The measured airplane was the airplane for Mars exploration being developed by Japan Aerospace Exploration Agency (JAXA) and Japanese universities. Its main wing span length was 2.4 m. The video grammetry measurement was performed using VICON’s system. Retroactive markers and stickers were put on the airplane. JAXA’s 6.5 m × 5.5 m Low-Speed Wind Tunnel was used. The airplane was mounted on the strut support with pitch-free or pitch-locked conditions. The deformations of the main wing bending, the main wing twisting, the tail boom bending, and the elevator deflection angle change were revealed quantitatively. The bending stiffness of a main wing spar that was designed as a safety factor of 2.8 at load factor of 5 was sufficient. The main wing spar was located around a center of pressure of an airfoil and it showed enough stiffness for twisting at nominal condition. The effects of the main wing bending and twisting, and the tail boom bending on the aerodynamic performance were estimated but they were in an acceptable range from the standpoint of the controllability of the aerodynamic performance using control surfaces. Even though the servo motor was located near the elevator and the linkage between the servo motor and the elevator was short, the measured elevator deflection angle was at most 4% smaller than the angle at no-wind condition. The obtained results and presented method are useful for control, flight data analysis, and design of lightweight airplanes. 展开更多
关键词 Wind Tunnel UAV DEFORMATION Video grammetry MARS Exploration
下载PDF
The Microwave Synthesis and Photo-catalytic Activity of SnO_2·TiO_2 Nano-composite
3
作者 杨水斌 廖学红 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2005年第3期78-80,共3页
A microwave-assisted heating approach was developed to fabricate SnO2·TiO2 nano-composite in an aqueoas sohaion of sulphuric acid in the presence of SnO2 nano-powder and titanium sulfate. Powder X-ray diffraction... A microwave-assisted heating approach was developed to fabricate SnO2·TiO2 nano-composite in an aqueoas sohaion of sulphuric acid in the presence of SnO2 nano-powder and titanium sulfate. Powder X-ray diffraction ( XRD ) pattern indicates that the products were a composite with both of anatase-type TiO2 and tetrahedrul SnO2. The prnducts were also characterized by transmission electron microscolry ( TEM ), photoluminescence (PL) spectra. The photo-catalytic property of the as-prepared sample has ulso been studied. The result indicates that the as-prepared sample is a good photo-catadyst. 展开更多
关键词 Nano- materials nano- composite photo- catalyst
下载PDF
Evaluation of the Photo-Protection of Eye-Patch Protectors Used in Phototherapy
4
作者 邓咏梅 易洁伦 +1 位作者 郭绮莲 黄小珍 《Journal of Donghua University(English Edition)》 EI CAS 2010年第1期1-5,共5页
An evaluation method for the practical photo-protection of eye-patch protectors (EPs) used in phototherapy for neonatal jaundice is developed.The protecting condition of neonatal eyes using EPs under typical photother... An evaluation method for the practical photo-protection of eye-patch protectors (EPs) used in phototherapy for neonatal jaundice is developed.The protecting condition of neonatal eyes using EPs under typical phototherapy light is simulated.The simulation system consists of a neonatal head manikin,an International Light ILT 900 wideband rapid portable spectroradiometer,a standard Air Shields Isolette incubator,and a Medela fluorescent phototherapy unit.The results show that the practical protection of neonatal eyes,provided by EPs which are affected by the material characteristic,shape design,and wearing condition,is comprehensively illustrated using the indices of illuminance (Ev in lux unit) and the spectral irradiance (E in μW/(cm2·nm) unit). 展开更多
关键词 eye-patch protector EP EVALUATION photo- protection PHOTOTHERAPY
下载PDF
基于计算特征的分布式空三计算任务调度研究
5
作者 颜丽玲 沙晋明 《科技创新与应用》 2024年第21期61-64,69,共5页
该文从倾斜摄影测量的现状出发,整理主流空三算法的计算流程,通过分析其算法特性,结合计算过程中使用的硬件资源,为提升计算过程中的任务调度效率,设计基于计算特征的分布式空三计算任务调度规则。并针对设计的调度规则开展一系列对比... 该文从倾斜摄影测量的现状出发,整理主流空三算法的计算流程,通过分析其算法特性,结合计算过程中使用的硬件资源,为提升计算过程中的任务调度效率,设计基于计算特征的分布式空三计算任务调度规则。并针对设计的调度规则开展一系列对比实验。实验结果表明,在梯度分布的计算节点上,使用基于计算特征的分布式空三计算任务调度规则的调度方式与不使用调度规则的方式相比,由于高性能主机在任务派送的优先级较高,因而任务包的周转度更高,使用调度规则的分布式集群在计算时长的表现上更好,在空三计算效率的提升方向及提升手段上具有一定的参考意义。 展开更多
关键词 分布式 任务调度 空三计算 倾斜摄影测量 优先级
下载PDF
数字化近景摄影测量系统及其应用 被引量:10
6
作者 贺跃光 王秀美 曾卓乔 《矿冶工程》 CAS CSCD 北大核心 2001年第4期1-3,共3页
介绍了中南大学研制的计算机无接触三维数字化近景摄影测量系统的构成、工作环境、功能、适用范围 ,以及系统的使用方法。并以其中电子经纬仪虚拟照片法观测隧道周边位移为例 ,分析了系统的原理、使用方法及其精度。结果表明 ,采用该系... 介绍了中南大学研制的计算机无接触三维数字化近景摄影测量系统的构成、工作环境、功能、适用范围 ,以及系统的使用方法。并以其中电子经纬仪虚拟照片法观测隧道周边位移为例 ,分析了系统的原理、使用方法及其精度。结果表明 ,采用该系统精度可靠 ,操作简便 ,且适应性强。 展开更多
关键词 数字化 近景摄影测量 计算机 隧道 位移观测 数据采集
下载PDF
小麦籽粒多酚氧化酶活性检测方法的研究 被引量:23
7
作者 杨朝柱 马传喜 +1 位作者 司红起 赵海军 《麦类作物学报》 CAS CSCD 2003年第1期37-40,共4页
以邻苯二酚为底物 ,采用分光光度法在 4 0 5 nm波长测定小麦全籽粒浸提液的吸光度变化 ,以此反映小麦多酚氧化酶活性的大小。从反应开始到 5 min时间段酶促反应最快 ,品种间差异较大 ,随后则逐渐下降 ;浸泡时间对全籽粒浸提法测定多酚... 以邻苯二酚为底物 ,采用分光光度法在 4 0 5 nm波长测定小麦全籽粒浸提液的吸光度变化 ,以此反映小麦多酚氧化酶活性的大小。从反应开始到 5 min时间段酶促反应最快 ,品种间差异较大 ,随后则逐渐下降 ;浸泡时间对全籽粒浸提法测定多酚氧化酶活性具有显著影响。浸泡时间小于 2 0 h,品种间差异较小 ;浸泡时间超过 30 h,酶液自身吸光值增加较多 ,因此浸泡时间以 2 5~ 30 h为宜。小麦多酚氧化酶与底物反应较适宜的温度和 p H为 35℃和6 . 展开更多
关键词 小麦 籽粒 多酚氧化酶 活性检测 分光光度法 浸泡时间 反应温度 pH值
下载PDF
三山岛金矿采场顶板危岩体推测方法 被引量:5
8
作者 赵兴东 刘洪磊 +1 位作者 郭甲腾 杨素俊 《东北大学学报(自然科学版)》 EI CAS CSCD 北大核心 2011年第7期1028-1031,共4页
在应用三维岩体不接触测量系统对采场顶板岩体结构面的几何特征参数进行识别基础上,自行研发三维岩体节理建模与分析系统,构建采场顶板三维岩体结构面空间分布模型.依据采场顶板岩体结构面的几何特征参数和延伸节理等结构面的空间特征,... 在应用三维岩体不接触测量系统对采场顶板岩体结构面的几何特征参数进行识别基础上,自行研发三维岩体节理建模与分析系统,构建采场顶板三维岩体结构面空间分布模型.依据采场顶板岩体结构面的几何特征参数和延伸节理等结构面的空间特征,通过延伸节理等结构面的空间交汇,识别采场危岩体赋存的空间位置、形态、体积等,并对采场顶板危岩体稳定性进行判断.应用上述研究成果,对三山岛金矿新立矿区40055#采场顶板结构面进行现场测量,确定采场顶板危岩体空间赋存位置,为采场顶板稳定性分析和危险性评价提供更加真实、可靠的数据支持. 展开更多
关键词 采场顶板 危岩体 数字摄影测量 3GSM
下载PDF
焊接变形测量方法研究进展 被引量:5
9
作者 刘建伟 魏永强 蒋志强 《热加工工艺》 CSCD 北大核心 2014年第17期5-9,14,共6页
伴随焊接过程产生的焊接变形会对其尺寸精度、外部形状、装配精度、结构特性和使用性能造成显著影响,因而在焊中和焊后对变形进行测量对于了解材料的变形机理,改善焊接工艺,减少焊后应力和变形,提高焊件的承载能力有着重要的理论意义和... 伴随焊接过程产生的焊接变形会对其尺寸精度、外部形状、装配精度、结构特性和使用性能造成显著影响,因而在焊中和焊后对变形进行测量对于了解材料的变形机理,改善焊接工艺,减少焊后应力和变形,提高焊件的承载能力有着重要的理论意义和工程价值。本文回顾了当前主要焊接变形测量手段,分析了各种测量方法的特点、适用性和局限性,重点讨论了近两年来本领域出现的新型光学方法,指出了焊接复杂变形测量中的关键问题和未来发展方向。 展开更多
关键词 焊接变形 激光扫描法 视频测量法 数字图像相关法
下载PDF
基于机载视频量测的3维城市建模 被引量:4
10
作者 吴军 张祖勋 张剑清 《中国图象图形学报》 CSCD 北大核心 2006年第8期1161-1170,共10页
3维城市模型的快速获取及更新是近十年来计算机视觉及数字摄影测量领域研究的热点。从实用、经济的角度出发,提出了集成城市数字地图、LIDAR data以及机载视频序列影像多数据源,基于数字摄影测量理论的半自动获取3维城市模型的解决办法... 3维城市模型的快速获取及更新是近十年来计算机视觉及数字摄影测量领域研究的热点。从实用、经济的角度出发,提出了集成城市数字地图、LIDAR data以及机载视频序列影像多数据源,基于数字摄影测量理论的半自动获取3维城市模型的解决办法,并在3维导航的数据生产实践中进行了验证,取得较好的生产效率及效果。 展开更多
关键词 3维城市模型 数字摄影测量 视频量测 序列影像
下载PDF
摄影测量中标记点编码与解码的方法 被引量:2
11
作者 陈玉萍 苏博 《技术与创新管理》 CSSCI 2009年第4期516-519,525,共5页
近景摄影测量中,可以在待测物体表面分布一些易于识别的标记点,以提高特征识别的准确性和精度,保证多幅图像间特征点对应匹配的可靠性。文中讨论了多种标记点的编码与解码,对各种标记点进行了分析,讨论了在不同的情况下使用不同的编码... 近景摄影测量中,可以在待测物体表面分布一些易于识别的标记点,以提高特征识别的准确性和精度,保证多幅图像间特征点对应匹配的可靠性。文中讨论了多种标记点的编码与解码,对各种标记点进行了分析,讨论了在不同的情况下使用不同的编码标记点可以起到准确识别和精确定位,提高效率,为图像识别打下良好的基础。 展开更多
关键词 近景摄影测量 编码标记点 图像识别
下载PDF
RTK在航测像控点测量中的应用 被引量:2
12
作者 程俊 刘怀文 李梦 《测绘与空间地理信息》 2007年第6期150-152,共3页
重点介绍了RTK技术在航测像控点测量中的应用,同时对GPS RTK技术的原理,软、硬件配置以及操作流程等方面也进行了简要阐述。通过应用并分析得出,GPS RTK技术完全可以满足航测像控点测量的精度要求,并且与常规方法相比具有很大的优越性,... 重点介绍了RTK技术在航测像控点测量中的应用,同时对GPS RTK技术的原理,软、硬件配置以及操作流程等方面也进行了简要阐述。通过应用并分析得出,GPS RTK技术完全可以满足航测像控点测量的精度要求,并且与常规方法相比具有很大的优越性,具有广泛的应用前景。 展开更多
关键词 GPS RTK 航测 像控点 测量
下载PDF
Positioning of Screw Holes Group Based on Digital Camera and Digital Control Drilling
13
作者 FENGWenhao LIJiansong YANLi SUGuozhong YUANXiuxiao ZHONGShengzhang JIHuiming 《Geo-Spatial Information Science》 2004年第4期235-242,共8页
Positioning of screw holes is an important production procedure for steel construction connecting with bolts. In this paper, a new production method is presented, in which the digital camera is used for taking picture... Positioning of screw holes is an important production procedure for steel construction connecting with bolts. In this paper, a new production method is presented, in which the digital camera is used for taking pictures of screw holes and other techniques are advanced. This paper also indicates that the pixels of CCD chip in photogrammetry should be chosen as all geometric units in an image, such as interior elements and all kinds of distortions. The measure can also simplify the camera calibration for determining the size of non-square pixel. 展开更多
关键词 digital camera screw hoies digital drilling machine PHOTOgrammetry multi-station photo- grammetry SELF-CALIBRATION bundle adjustment
下载PDF
RECENT DEVELOPMENTS IN PHOTOINITIATED CROSSLINKING OF POLYETHYLENE AND ITS INDUSTRIAL APPLICATIONS 被引量:3
14
作者 翟保钧 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2001年第2期189-207,共19页
The recent developments in the photoinitiated cross-linking of polyethylene and the significant breakthrough of its industrial application are reviewed. The enhanced photo-initiation system, the dynamics of photoiniti... The recent developments in the photoinitiated cross-linking of polyethylene and the significant breakthrough of its industrial application are reviewed. The enhanced photo-initiation system, the dynamics of photoinitiated crosslinking, the optimum conditions, the crystal morphological structures and related properties, and the photo- and thermo-oxidation stability of photocrosslinked polyethylene (XLPE) materials have been elucidated systematically. A new technique for producing photocrosslinked XLPE-insulated wire and cable is described in detail. It can be expected that the future applications of photocrosslinking technique of polyolefins will be very promising. 展开更多
关键词 POLYETHYLENE enhanced photocrosslinking systems morphological structures and properties photo- and thermooxidation stability photocrosslinked XLPE insulated wire and cable
下载PDF
Research perspectives for catalytic valorization of biomass 被引量:3
15
作者 Weiping Deng Ye Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第3期102-104,I0004,共4页
Efficient utilization of biomass for the supply of energy and synthetic materials would mitigate the heavy reliance on fossil resources and the growing CO_(2) emission, thus contributing to establishing sustainable an... Efficient utilization of biomass for the supply of energy and synthetic materials would mitigate the heavy reliance on fossil resources and the growing CO_(2) emission, thus contributing to establishing sustainable and carbon–neutral societies. Much effort has been devoted to catalytic transformations of lignocellulosic biomass, the most abundant and nonedible form of biomass. 展开更多
关键词 BIOMASS Lignocellulose fractionation CAO/CAC bond cleavage Thermo-/photo-/electro-catalysis Renewable chemicals and materials
下载PDF
Identification of emission sources of umbral flashes using phase congruency 被引量:2
16
作者 Song Feng Lan Yu +1 位作者 Yun-Fei Yang Kai-Fan Ji 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第8期1001-1010,共10页
The emission sources of umbral flashes (UFs) are believed to be closely related to running umbral and penumbral waves, and are concluded to be associated with umbral dots in the solar photosphere. Accurate identific... The emission sources of umbral flashes (UFs) are believed to be closely related to running umbral and penumbral waves, and are concluded to be associated with umbral dots in the solar photosphere. Accurate identification of emission sources of UFs is crucial for investigating these physical phenomena and their inherent relationships. A relatively novel model of shape perception, namely phase congruency (PC), uses phase information in the Fourier domain to identify the geometrical shape of the region of interest in different intensity levels, rather than intensity or gradient. Previous studies indicate that the model is suitable for identifying features with low contrast and low luminance. In the present paper, we applied the PC model to identify the emission sources of UFs and to locate their positions. For illustrating the high performance of our proposed method, two time sequences of Ca n H images derived from the Hinode/SOT on 2010 August 10 and 2013 August 20 were used. Furthermore, we also compared these results with the analysis results that are identified by the traditional/classical identification methods, including the gray-scale adjusted technique and the running difference technique. The result of our analysis demonstrates that our proposed method is more accurate and effective than the traditional identification methods when applied to identifying the emission sources of UFs and to locating their positions. 展开更多
关键词 techniques image processing -- Sun chromosphere -- Sun photo- sphere -- sunspots -- convection
下载PDF
Intense up-conversion emissions of yb3+/Dy3+ co-doped A12O3 nanopowders prepared by non-aqueous sol-gel method* 被引量:2
17
作者 李成仁 李淑凤 +3 位作者 董斌 孙景昌 卜晓峰 范旭楠 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第9期505-508,共4页
yb3+/Dy3+ co-doped A1203 nanopowders have been prepared by the non-aqueous sol-gel method and their up- conversion photoluminescence spectra are measured under excitation by a 980-nm semiconductor laser. The results... yb3+/Dy3+ co-doped A1203 nanopowders have been prepared by the non-aqueous sol-gel method and their up- conversion photoluminescence spectra are measured under excitation by a 980-nm semiconductor laser. The results show that there are comparatively abundant spectra of up-conversion emissions centered at 378, 408, 527 and 543, and 663 nm, corresponding to 4C9/2→ 6H13/2, 4C9/2→ 6Hll/2, 4115/2 → 6H13/2, and 4F9/2 →6Hll/2 transitions of Dy3+, respectively. Two-photon and three-photon processes are involved in ultraviolet, violet, green, and red up-conversion emissions. The energy transition between Yb3+ and Dy3+ is discussed. 展开更多
关键词 yb3+/Dy3+ co-doped A1203 nanopowders non-aqueous sol-gel method photo- lumi-nescence spectra up-conversion emission
下载PDF
新型遥感立体成像技术初步研究
18
作者 郭培基 《光学精密工程》 EI CAS CSCD 1994年第4期49-57,共9页
主要讨论了信息获取技术和数字三维成图及其显示办法:论述了三线阵数字摄测系统的原理及其组成,较详细地讨论了系统各主要参数及其确定,重点放在光学系统的参数选择,并设计了实用的光学系统;运用航测原理建立了完整的三线阵数字摄... 主要讨论了信息获取技术和数字三维成图及其显示办法:论述了三线阵数字摄测系统的原理及其组成,较详细地讨论了系统各主要参数及其确定,重点放在光学系统的参数选择,并设计了实用的光学系统;运用航测原理建立了完整的三线阵数字摄测系统求解立体信息的数学模型,并对解的稳定性进行了分析讨论,提出了用取随机的定向片距来解决解的稳定性的方法,讨论了三维立体求解结果的显示技术。 展开更多
关键词 遥感 立体成象 数字成图 数字摄测系统
下载PDF
Modeling Gross Primary Production by Integrating Satellite Data and Coordinated Flux Measurements in Arid and Semi-Arid China 被引量:1
19
作者 WANG He-Song JIA Gen-Suo +2 位作者 FENG Jin-Ming ZHAO Tian-Bao MA Zhu-Guo 《Atmospheric and Oceanic Science Letters》 2010年第1期7-13,共7页
Assessing large-scale patterns of gross primary production (GPP) in arid and semi-arid (ASA) areas is important for both scientific and practical purposes.Remote sensing-based models,which integrate satellite data wit... Assessing large-scale patterns of gross primary production (GPP) in arid and semi-arid (ASA) areas is important for both scientific and practical purposes.Remote sensing-based models,which integrate satellite data with input from ground-based meteorological measurements and vegetation characteristics,improve spatially extended estimates of vegetation productivity with high accuracy.In this study,the authors simulated GPP in ASA areas by integrating moderate resolution imaging spectral radiometer (MODIS) data with eddy covariance and meteorological measurements at the flux tower sites using the Vegetation Photosynthesis Model (VPM),which is a remote sensing-based model for analyzing the spatial pattern of GPP in different land cover types.The field data were collected by coordinating observations at nine stations in 2008.The results indicate that in the region during the growing season GPP was highest in cropland sites,second highest in woodland sites,and lowest in grassland sites.VPM captured the temporal and spatial characteristics of GPP for different land covers in ASA areas.Further,Enhanced Vegetation Index (EVI) had a strong liner relationship with GPP in densely vegetated areas,while the Normalized Difference Vegetation Index (NDVI) had a strong liner relationship with GPP over less dense vegetation.This study demonstrates the potential of satellite-driven models for scaling-up GPP,which is a key component for studying the carbon cycle at regional and global scales. 展开更多
关键词 gross primary production vegetation photo- synthesis model eddy covariance remote sensing coordinated observation arid and semiarid areas
下载PDF
浅谈无人机航空摄影测量技术在水利工程中的应用 被引量:23
20
作者 吴定邦 《江西水利科技》 2016年第1期57-61,共5页
水利工程高程准确性至关重要.本文结合工程实践,利用无人机快速灵活、成本低的优势,将无人机航空摄影测量技术和RTKGPS技术运用在水利工程中,生成数字化地形图.该方法可以提高工效,节约生产成本,满足工程建设要求.
关键词 无人机 航空摄影测量系统 水利工程 应用
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部