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Right-and-left visual field stimulation:A frequency and space mixed coding method for SSVEP based brain-computer interface

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Science China(Information Sciences) 2011年第12期54卷 2512-2518页

作者： YAN Zheng, gao xiaorong & gao ShangKai Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China Department of Biomedical Engineering School of Medicine Tsinghua University Beijing China

On the condition of using limited frequencies, fewer targets could be presented in brain-computer interface (BCI) based on steady-state visual evoked potentials (SSVEP). This paper proposes a novel coding method for SSVEP that, through a combination of frequency and spatial information, could increase the number of targets. Each target was composed of two flickers placed in the right-and-left visual fields. Given the role of the optic chiasm in the vision pathway, the two frequency components could be projected to contralateral occipital regions. Canonical correlation analysis (CCA) was utilized to detect the frequency components from the right or left visual cortex. Asymmetric index as a supplementary feature was also computed. Linear discriminant analysis (LDA) was used for target recognition. The attractive feature of this method is that it would substantially increase the number of targets. If the number of frequency was N, the method could present N times more targets than conventional SSVEP-based BCIs.

关键词： brian-computer interface (BCI) frequency-space mixed coding steady-state visual evoked potential (SSVEP)

BCI Controlled Robot Contest on the 50th Anniversary of Brain-Computer Interfaces

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Brain Science Advances 2023年第4期9卷 237-241页

作者： Bingchuan Liu Xiaogang Chen Jingjing Chen Dan Zhang Yijun Wang xiaorong gao Department of Biomedical Engineering School of MedicineTsinghua UniversityBeijing 100084China Institute of Biomedical Engineering Chinese Academy of Medical Sciences and Peking Union Medical CollegeTianjin 300020China Department of Psychology School of Social SciencesTsinghua UniversityBeijing 100084China State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Dioision of Biology and Biological Engineering California Institute of TechnologyPasadena 91125USA

Introduction Is it feasible to employ neural signals for the purpose of communication?In 1938,this thoughtprovoking query was visually embodied in a sketch received by Hans Berger,a German Professor of Psychiatry reno... 详细信息

关键词： sketch Robot feasible

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多尺度地图空间居民地语义相似度计算方法

测绘学报 2022年第1期51卷 95-103页

作者：高晓蓉闫浩文禄小敏兰州交通大学测绘与地理信息学院甘肃兰州730070 地理国情监测技术应用国家地方联合工程研究中心甘肃兰州730070 甘肃省地理国情监测工程实验室甘肃兰州730070

地图综合的本质是一种空间相似变换,制图者在相似原则的指导下实施概括,读图者从包含相似性的地图中形成心象地图、重构现实世界。因此,多尺度地图空间中的相似关系研究非常重要。然而,由于相似的可计算性差,且其计算的目的在于揭示更... 详细信息

地图综合的本质是一种空间相似变换,制图者在相似原则的指导下实施概括,读图者从包含相似性的地图中形成心象地图、重构现实世界。因此,多尺度地图空间中的相似关系研究非常重要。然而,由于相似的可计算性差,且其计算的目的在于揭示更深层次的信息,地图综合中相似关系尤其是语义相似关系的研究相对较少。针对这一问题,本文以语义功能区约束下的大比例尺街区式居民地合并(1∶1750至1∶4000)为例,基于匹配距离模型计算建筑物合并中的语义相似度,得到语义相似度在关键比例尺节点的值,并对结果进行分析、评价。试验表明,语义功能区约束下的建筑物合并符合读图者的地图认知需求,本文所述方法有助于地图更好地发挥信息传输载体的作用。

关键词：语义相似度街区式居民地合并地图综合多尺度地图空间匹配距离模型

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Rapid Amplification of 5′ cDNA End of S. Liaotungensis Choline Monooxygenase Using Inverse PCR RACE

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High Technology Letters 2002年第1期8卷 5-7页

作者：李秋莉 gao xiaorong FAN Qi Yuan Xiaodong Liu Dawei An Lijia Bioengineering Department of Dalian University of Technology Dalian 116012 P.R.China Biology Department of Liaoning Normal University Dalian 116029 P.R.China Bioengineering Department of Dalian University of Technology Dalian 116012 P.R.China TaKaRa Biotechnology Dalian Co. Ltd. Dalian 116600 P.R.China

Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase, the authors successfully cloned the 5′ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a specially designed 5′-phosphated RT primer and two pairs of specific inverse PCR primers. Compared with the anchored PCR RACE, inverse PCR RACE has better specificity and higher amplification.

关键词： DNA 放大反演PCR RACE应用

Source Contributions to PM2.5 under Unfavorable Weather Conditions in Guangzhou City,China

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Advances in Atmospheric Sciences 2018年第9期35卷 1145-1159页

作者： Nan WANG Zhenhao LING Xuejiao DENG Tao DENG Xiaopu LYU Tingyuan LI xiaorong gao Xi CHEN Institute of Tropical and Marine Meteorology China Meteorological AdministrationGuangzhou 510000China School of Atmospheric Sciences Sun Yat-sen UniversityGuangzhou 510000China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversiiyHong Kong 999077China Ecological Meteorology Centez Guangdong Provincial Meteorological Bureau Guangzhou 510000China Guangzhou Meteorological Observatory Guangzhou 510000China School of Environmental Science and Engineering Sun Yat-sen UniversiiyGuangzhou 510000China

Historical haze episodes（2013–16） in Guangzhou were examined and classified according to synoptic weather *** types of weather systems were found to be unfavorable, among which ＂foreside of a cold front＂（FC） and ＂sea high pressure＂（SP） were the most frequent（〉 75% of the total）. Targeted case studies were conducted based on an FC-affected event and an SP-affected event with the aim of understanding the characteristics of the contributions of source regions to fine particulate matter（PM（2.5）） in Guangzhou. Four kinds of contributions—namely, emissions outside Guangdong Province（super-region）, emissions from the Pearl River Delta region（PRD region）, emissions from Guangzhou–Foshan–Shenzhen（GFS region）, and emissions from Guangzhou（local）—were investigated using the Weather Research and Forecasting–Community Multiscale Air Quality model. The results showed that the source region contribution differed with different weather systems. SP was a stagnant weather condition, and the source region contribution ratio showed that the local region was a major contributor（37%）, while the PRD region, GFS region and the super-region only contributed 8%, 2.8% and 7%, respectively, to PM（2.5） concentrations. By contrast, FC favored regional transport. The super-region became noticeable,contributing 34.8%, while the local region decreased to 12%. A simple method was proposed to quantify the relative impact of meteorology and emissions. Meteorology had a 35% impact, compared with an impact of-18% for emissions, when comparing the FC-affected event with that of the SP. The results from this study can provide guidance to policymakers for the implementation of effective control strategies.

关键词： WRF Community Multiscale Air Quality model source contribution unfavorable weather system fine partic-ulate matter

Assessment of the uncertainties in temperature change in China during the last century

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Chinese Science Bulletin 2010年第19期55卷 1974-1982页

作者： LI QingXiang DONG WenJie LI Wei gao xiaorong JONES P KENNEDY J PARKER D National Meteorological Information Center Beijing 100081 China Beijing Normal University Laboratory of Surface Process and Resources Economies Beijing 100875 China National Meteorological Center Beijing 100081 China Climatic Research Unit School of Environmental Sciences University of East Anglia Norwich NR4 7TJ UK Met Office Hadley Centre Exeter EX1 3PB UK

We have used the China Homogenized Historic Temperature dataset and some long-term station series of the neighbor countries from CRUTEM3,a 5°×5° gridded dataset of monthly mean temperature since 1900,to provide a 107-year record of surface temperature trends and *** derived a comprehensive set of uncertainty estimates to accompany the data:measurement and sampling errors,uncertainties in temperature bias estimates,and uncertainties arising from limited observational coverage on large-scale averages have all been *** reanalysed the temperature changes during the period of *** best estimates of trends for 1900-2006 with uncertainties at 95% confidence range are about 0.09±0.017°C/decade for the year as a whole,and 0.14±0.021°C/decade,0.11±0.021°C/decade,0.04±0.017°C/decade,and 0.07±0.017°C/decade for winter,spring,summer and autumn *** 1954-2006,the trends for annual,winter,spring,summer and autumn are:0.26±0.032°C/decade,0.35±0.046°C/decade,0.25±0.051°C/decade,0.16±0.037°C/decade and 0.22±0.055°C/*** saw the most significant warming trend in both 1900-2006 and 1954-2006,while during the most recent period(the satellite era,1979-2006),all the seasons show similar warming trends:0.45±0.13°C/decade,0.51±0.11°C/decade,0.52±0.16°C/decade,0.37±0.10°C/decade and 0.50±0.16°C/decade for annual,winter,spring,summer and *** arising from urbanization have been evaluated as less than 5% of the total warming trend for 1951-2001,so this bias was not removed.

关键词：不确定性温度变化中国历史评估变暖趋势偏差估计月平均温度抽样误差

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车轮踏面动态感应热成像缺陷检测方法研究

仪器仪表学报 2022年第3期43卷 163-170页

作者：唐思颖高晓蓉彭建平张翔西南交通大学物理科学与技术学院成都610031

涡流脉冲热成像是一种新型的无损检测技术,具有检测速度快,灵敏度高,探测范围大的特点。为适应车轮踏面缺陷的动态检测,本文提出了一种适应车轮踏面廓形的矩形磁轭电磁感应激励传感结构。通过传感器结构的磁路模型推导,从理论上证明了... 详细信息

涡流脉冲热成像是一种新型的无损检测技术,具有检测速度快,灵敏度高,探测范围大的特点。为适应车轮踏面缺陷的动态检测,本文提出了一种适应车轮踏面廓形的矩形磁轭电磁感应激励传感结构。通过传感器结构的磁路模型推导,从理论上证明了传感结构的可行性。通过数值模拟计算分析了踏面表面检测区域的磁场与涡流场分布,并对比了矩形磁轭与直导线的检测结果。在此基础上,本文搭建了一套车轮自动探伤检测系统,能够实现65 mm/s速度下的缺陷动态测量。结果表明,设计的矩形磁轭传感结构可优化感应加热的均匀性,对车轮踏面浅表层疲劳裂纹(轴向表面开口)具有更好的检测结果。

关键词：涡流脉冲热成像感应激励线圈车轮踏面疲劳缺陷动态无损检测

32-site microelectrode modified with Pt black for neural recording fabricated with thin-film silicon membrane

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Science China(Information Sciences) 2014年第5期57卷 292-298页

作者： CHEN SanYuan PEI WeiHua ZHAO Hui GUI Qiang TANG RongYu CHEN YuanFang FANG XiaoLei HONG Bo gao xiaorong CHEN HongDa State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of Sciences Institute of Neural Engineering Department of Biomedical Engineering Tsinghua University

Multi-electrode array is an important tool in the study of neural-network,cognition,remembrance,as well as brain-computer-interface,***-like 32-site microelectrodes are developed with *** use of integrated circuit technology,the length of the electrodes,the area of the recording sites,as well as the spaces between the sites are closely ***2/SiNx/SiO2composite dielectric membrane and Pt black are introduced to improve the characteristics of the *** whole thickness of the thin-film probe was 21μ*** combining the modifying process with the micro-fabrication method,this kind of silicon based microelectrode satisfies high-density recording and the performance characterization is evaluated by test in vitro and in vivo.

关键词： microelectrode brain-computer interface thin-film Si Pt black neural recording

Separation and Purification of Thrombin-like Enzymes by Affinity Adsorbents

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High Technology Letters 2001年第4期7卷 13-15页

作者：杨青 Xu Xiaoming Hu Xuejun gao xiaorong Dong Xinyan Su Zhiguo An Lijia Bioengineering Institute Dalian University of Technology Takara Biotech Dalian Co. Ltd. Dalian Development Zone State Key Laboratory of Biochemical Engineering Institute of Chemical Metallurgy CAS

An affinity adsorbent, benzamidine Sepharose 4B, was used to separate and purify thrombin like enzymes. The p aminobenzamidine as a specific ligand was coupled to the matrix-Sepharose 4B. The recombinant thrombin like enzyme-defibrase was used as a model in order to evaluate the efficiency of this biospecific affinity adsorbent. The homogeneity of the enzyme preparation was comfirmed as one band on sodium dodecyl sulfate polyacrylamide gel electrophoresis.

关键词： Affinity chromatography Ligand Benzamidine Purification Thrombin like enzyme