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A Novel Approach to Text Detection and Extraction from Videos by Discriminative Features and Density

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Chinese Journal of Electronics 2014年第2期23卷 322-328页

作者： wei Baogang ZHANG Yin YUAN jie LIU Yonghuai WANG Lidong College of Computer Science and Technology Zhejiang University Department of Computer Science Aberystwyth University Qianjiang College Hangzhou Normal University

Text is very important to video retrieval,index, and understanding. However, its detection and extraction is challenging due to varying background, low contrast between text and non-text regions, and perspective distortion. In this paper, we propose a novel two phase approach to tackling this problem by discriminative features and edge density. The first phase firstly defines and extracts a novel feature called edge distribution entropy and then uses this feature to remove most non-text regions. The second phase employs a Support vector machine(SVM) to further distinguish real text regions from nontext ones. To generate inputs for SVM, additional three novel features are defined and extracted from each region:a foreground pixel distribution entropy, skeleton/size ratio, and edge density. After text regions have been detected, texts are extracted from such regions that are surrounded by sufficient edge pixels. A comparative study using two publicly accessible datasets shows that the proposed method significantly outperforms the selected four state of the art ones for accurate text detection and extraction.

关键词： Text detection Text extraction Edge distribution entropy Foreground pixel distribution entropy Edge density

Large and meso-α scale characteristics of intense rainfall in the mid- and lower reaches of the Yangtze River

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Chinese Science Bulletin 2002年第9期47卷 779-786页

作者： Shunli Zhang Shiyan Tao Qingyun Zhang jie wei Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

Meteorological conditions associated with intense rainfall and great floods over mid- and lower reaches of Yangtze River are studied by analyzing the large-, synoptic-and meso-a-scale circulation systems for 1991, 1996 and 1998. It is found that the advance and retreat of subtropical high over the West Pacific, the monsoon moisture surge from the South China Sea, cold air outbreak over mid- and high-latitudes, and the meso-α scale systems (250-2500 km) from the Tibetan Pleateau as well, are responsible for intense rainfall over the Yangtze River Valley. The persistent and heavy rains and great floods over the Yangtze River Valley occurred when all these four systems are synergetic or in phase lock.

关键词： mid- and lower reaches of Yangtze River heavy rains great floods monsoon moisture surge phase lock.

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高功率纳秒级激光二极管高侧驱动电路

激光与红外 2024年第2期54卷 171-178页

作者：金明泽王臣朱福杨信诚李智冰赵晓琛何伟基张闻文南京理工大学电子工程与光电技术学院江苏南京210094

纳秒级高功率的激光发射系统对激光雷达的探测性能产生重要影响。本文对普遍使用的激光二极管低侧栅极驱动电路进行修改得到高侧栅极驱动方式,使之能够适用于共阴极激光发射电路。该高侧驱动方式采用了一个半桥驱动器,两个GaN FET作为... 详细信息

纳秒级高功率的激光发射系统对激光雷达的探测性能产生重要影响。本文对普遍使用的激光二极管低侧栅极驱动电路进行修改得到高侧栅极驱动方式,使之能够适用于共阴极激光发射电路。该高侧驱动方式采用了一个半桥驱动器,两个GaN FET作为核心器件来控制激光二极管的发光。文中分析了该拓扑结构中电压、电容、电阻、电感等因素对流经激光器电流波形的影响。经过实验测试,在高重复频率下该电路能够产生3.1 ns脉冲宽度,约65 W的峰值功率,能够作为激光雷达的发射模块对场景进行扫描成像。

关键词：纳秒级高功率激光发射高侧栅极驱动共阴极高重复率

What took you so long?Peptide-receptor kinase signaling mediates reproductive isolation in plants

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Science Bulletin 2019年第19期64卷 1390-1392页

作者： Yu-jie Li Jia-Qi Pei wei-Hua Tang National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologyChinese Academy ofSciencesShanghai200032China University of the Chinese Academy of Sciences Beijing100049China

The peptide-receptor kinase-based intercellular signaling becomes an important molecular base for various aspects of plant life activities[1],particularly exemplified in the extensive molecular interactions in the journey of pollen tube growth in pistil of flowering plants[2].Researches in the past two decades demonstrated that peptide-receptor kinase signaling complexes mediat epollen tube promotion,guidance and reception,as well as selfincompatibility and gamete fusion.A recent exciting discovery published on Science by Zhong et *** the biological functions of peptide-receptor kinase signaling to facilitating formation of a new plant species[3].

关键词： so long Peptide-receptor in plants

Synthesis of NiCr_2O_4 spinel coatings with high emissivity by plasma spraying

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 266-270页

作者： Zhen-qi Zhu Xu-dong Cheng wei-ping Ye jie Min School of Materials Science and Technology Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

Air plasma spraying （APS） was used to produce high emissivity coatings with a NiCr204 spinel structure. The relationship between the emissivity and the crystal structure was investigated. X-ray diffraction （XRD） analyses show that NiCr204 spinel has been fabri- cated with the space group Fd3m. Scanning electron microscope （SEM） photographs show that the coating consists of a laminated structure with homogeneous grains and high porosity because of the unique feature of plasma spraying. The emissivity measurement and Fourier transformation infrared radiation （FT-IR） spectra show that NiCr204 has a high emissivity of about 0.91 because of its special spinel structure APS is a suitable method to produce high emissivity coatings.

关键词： infrared radiation coatings plasma spraying emissivity crystal structure industrial ftLrnaces

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湖南农业防灾减灾能力体系建设研究

湖南农业科学 2024年第7期 81-86页

作者：周宇邓文刘贝刘英谭杰扬湖南省微生物研究院湖南长沙410000 湖南省农业经济和农业区划研究所湖南长沙410125

通过分析湖南气候特征、主要农业气象灾害时空分布及影响、农业防灾减灾能力体系建设存在的主要问题,结果表明:湖南农业气象灾害发生频率高,对农业生产危害最严重的是暴雨洪涝、季节性干旱,其次是低温冷(冻)害、高温热害;当前湖南在农... 详细信息

通过分析湖南气候特征、主要农业气象灾害时空分布及影响、农业防灾减灾能力体系建设存在的主要问题,结果表明:湖南农业气象灾害发生频率高,对农业生产危害最严重的是暴雨洪涝、季节性干旱,其次是低温冷(冻)害、高温热害;当前湖南在农业防灾减灾能力体系建设中存在基础设施薄弱、监测预警智慧化水平不高、应急响应保障能力不强、防灾减灾体制机制不完善、农业生产防灾技术应用不充分等问题。提出了建立健全面广长效的工程防御体系、精准实效的监测预警体系、顺畅高效的应急响应体系、多元多品的农业保险体系、适应逆境的农业生产体系、有效联动的组织管理体系等对策建议。

关键词：气候农业气象灾害防灾减灾体系对策湖南

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石油炼化专业技能培训平台的研究

机电产品开发与创新 2024年第4期37卷 189-192页

作者：陈杰吴义维王忠平青岛石大石仪科技有限责任公司山东青岛266000 山东中石大后勤服务有限公司山东青岛266000

石油炼化专业技能培训平台主要围绕化工企业实际生产过程中的流体输送工艺以及物料输送过程中所涉及到的一些问题展开,主要设计思想是将工厂中流体输送相关设备、泵、阀门、仪表、流量计、液位计等诸多元素集中在一套装置中,开展石化专... 详细信息

石油炼化专业技能培训平台主要围绕化工企业实际生产过程中的流体输送工艺以及物料输送过程中所涉及到的一些问题展开,主要设计思想是将工厂中流体输送相关设备、泵、阀门、仪表、流量计、液位计等诸多元素集中在一套装置中,开展石化专业领域的流体输送的相关知识与技能培训。达到提高化工、轻工类院校专业实践教学水平,充分体现职业教育的特色,同时可面向危化企业员工开展入职教育、职业技能提升培训之用。

关键词：化工生产培训平台孪生三维

Simultaneous CO2 capture and H2 generation using Fe2O3/Al2O3 and Fe2O3/CuO/Al2O3 as oxygen carriers in single packed bed reactor via chemical looping process

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Frontiers of Environmental Science & Engineering 2015年第6期9卷 1117-1129页

作者： jie ZHU wei WANG Xiuning HUA Zhou XIA Zhou DENG School of Environment Tsinghua University Beijing 100084 China Jian Kun New Energy Technology Co. Ltd. Beijing 100085 China

The chemical looping concept provided a novel way to achieve carbon separation during the production of energy or substances. In this work, hydrogen generation with inherent CO2 capture in single packed bed reactor via this concept was discussed. Two oxygen carriers, Fe203 60 wt.% and Fe2O3 55 wt.%/CuO 5 wt.% supported by Al2O3, were made by ball milling method. First, according to the characteristics of the reduction breakthrough curve, a strict fuel supply strategy was selected to achieve simultaneous CO2 capture and HE production. Then, in the long term tests using CO as fuel, it was proved that CuO addition improved hydrogen generation with the maximum intensity of 3700 μmol H2·g^-1 Fe2O3 compared with Fe-Al of 2300 μmol HE.g^-1 Fe2O3. The overall CO2 capture efficiency remained 98%- 98.8% over 100 cycles. Moreover, the reactivity of deactivated materials was recovered nearly like that of fresh ones by sintering treatment. Finally, two kinds of complex gases consist of CO, HE, CH4 and CO2 were utilized as fuels to test the feasibility. The results showed all components could be completely converted by Fe-Cu- Al in the reduction stage. The intensity of hydrogen production and the overall CO2 capture efficiency were in the range of 2000-2400 μnol H2^g^-1 Fe2O3 and 89%, 95%, respectively.

关键词： CO2 capture chemical looping hydrogengeneration iron based oxygen carriers single packed bedreactor long-term test complex gases fuel

Assessment of mouse BMMNC DNA damage with a two-tailed comet assay after X-ray and carbon ion total body irradiation

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Nuclear Science and Techniques 2018年第6期29卷 1-8页

作者： Fang Liu Zhuan-Zi Wang wen-Jian Li wei wei Bing-Rong Dang Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000 China University of Chinese Academy of Sciences Beijing 100049China

The two-tailed comet assay(2T-comet assay) is a method for simultaneously evaluating DNA single-strand breaks(SSBs) and double-strand breaks(DSBs). In the present study, the endonuclease DNase I and hydrogen peroxide were used to induce DSBs and SSBs in bone marrow mononuclear cells(BMMNCs) from mice, and the damaged DNAs were assessed with a 2T-comet assay. The results demonstrated that this method can detect and discriminate between BMMNC DNA SSBs and DSBs simultaneously. Using this method, we studied DNA damage in BMMNCs from female BALB/c mice after total body irradiation with X-rays and carbon ions. The results indicated that these two types of radiation induced serious DNA damage in BMMNCs in a dose-dependent *** DNA damage induced by carbon ions was more severe than that induced by X-rays at the same dose, and a high dose of carbon ion radiation was more likely to cause death in mice. The DSBs and SSBs induced by X-rays were the highest on the 3rd day post-IR. For carbon ion radiation,DSBs were the most serious on the 3rd day, while SSBs were more obvious on the 3rd day and 13th day *** ratio of DSBs/SSBs was clearly related to the different types of radiation.

关键词： DNA 碳离子损坏彗星尾巴身体金鼠标