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一种分割重叠粘连细胞图像的改进算法

中国生物医学工程学报 2006年第4期25卷 390-395页

作者：潘晨闫相国郑崇勋西安交通大学生物医学信息工程教育部重点实验室西安710049

为了专门分割重叠粘连细胞的图像,提出一种基于局部流域变换的迭代剥离算法。具体分割过程分为两个阶段,序贯处理胞浆和核区重叠,逐渐剥离重叠细胞。每个阶段均通过自适应距离变换分离重叠细胞,利用单个细胞形态特征控制腐蚀程度使得种... 详细信息

为了专门分割重叠粘连细胞的图像,提出一种基于局部流域变换的迭代剥离算法。具体分割过程分为两个阶段,序贯处理胞浆和核区重叠,逐渐剥离重叠细胞。每个阶段均通过自适应距离变换分离重叠细胞,利用单个细胞形态特征控制腐蚀程度使得种子区域最大化,然后通过流域变换重建得到细胞间边界。算法能够克服细胞多核、胞浆颗粒性等干扰,适合自动化处理。骨髓和外周血涂片的分割试验表明分割精度约是传统流域算法的2倍,而运算时间并没有增加很多。

关键词：图像处理流域变换重叠细胞

Ambient electrosynthesis of urea from carbon dioxide and nitrate over Mo_(2)C nanosheet

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Chinese Chemical Letters 2024年第8期35卷 319-323页

作者： Yue Zhang Xiaoya Fan xun He Tingyu Yan Yongchao Yao Dongdong zheng Jingxiang Zhao Qinghai Cai Qian Liu Luming Li Wei Chu Shengjun Sun Xuping Sun College of Chemistry and Chemical Engineering and Key Laboratory of Photonic and Electronic Bandgap MaterialsMinistry of EducationHarbin Normal UniversityHarbin 150025China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China Institute for Advanced Study Chengdu UniversityChengdu 610106China College of Chemistry Chemical Engineering and Materials ScienceShandong Normal UniversityJi’nan 250014China

Electrocatalytic synthesis of urea through C-N bond formation,converting carbon dioxide(CO_(2))and ni-trate(NO_(3)^(-)),presents a promising,less energy-intensive alternative to industrial urea production *** this communication,we report the application of Mo_(2)C nanosheets-decorated carbon sheets(Mo_(2)C/C)as a highly efficient electrocatalyst for facilitating C-N coupling in ambient urea *** CO_(2)-saturated 0.2 mol/L Na_(2)SO_(4)solution containing 0.05 mol/L NO_(3)^(-),the Mo_(2)C/C catalyst achieves an impres-sive urea yield of 579.13μg h^(-1)mg^(-1)with high Faradaic efficiency of 44.80%at-0.5 V versus the reversible hydrogen *** theoretical calculations reveal that the multiple Mo active sites enhance the formation of^(∗)CO and^(∗)NH_(2)intermediates and facilitate their C-N *** research propels the use of Mo_(2)C-based electrodes in electrocatalysis and accentuates the capabilities of binary metal-based catalysts in C-N coupling reactions.

关键词： Mo_(2)C Multiple active sites C-N coupling Electrocatalysis Urea synthesis Density functional theory calculation

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星敏感器遮光罩出口杂光的辐照度测试

光学精密工程 2017年第6期25卷 1464-1471页

作者：陈赟郑循江刘宗明杜宣上海航天控制技术研究所上海200233

面向星敏感器在轨应用时杂光抑制的迫切需求,开展了星敏感器遮光罩出口杂光辐照度分布定量测试。基于微型光纤光谱仪、二维高精度位移台以及太阳模拟器搭建了可逐点扫描的杂光测试平台,并将辐射测量软件与运动控制软件进行有效整合,开... 详细信息

面向星敏感器在轨应用时杂光抑制的迫切需求,开展了星敏感器遮光罩出口杂光辐照度分布定量测试。基于微型光纤光谱仪、二维高精度位移台以及太阳模拟器搭建了可逐点扫描的杂光测试平台,并将辐射测量软件与运动控制软件进行有效整合,开发系统集成测试软件,完成遮光罩出口杂光辐照度分布的实时定量测量。针对获取的不同光照入射角下遮光罩出口处的测量计数值,根据测量时设定的积分时间及保存的暗背景数据以及光谱仪定标数据计算获得遮光罩出口处的杂光辐照度分布。数据处理结果表明:遮光罩在出口处的杂光辐照度约为102 W/cm^2,而且分布不均匀。基于误差分析理论构建了测量误差模型,误差计算结果为4.87%,表明了测量方案的合理性和可行性。测量数据可为星敏感器系统方案设计、论证、测试、定型及应用提供重要的技术支持。

关键词：星敏感器遮光罩杂散光抑制照度分布数据处理误差分析

广东经济增长的影响因素、路径依赖和形成竞争优势的路径选择

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特区经济 2005年第4期 20-23页

作者：谭政勋暨南大学珠海学院金融系 519070

一、广东经济增长的影响因素国内外学者已对经济增长的源泉、路径作出了有益的探索和研究。概括起来，大家一致认为影响经济增长的主要4大因素是：要素禀赋(主要有劳动力、物质资本、人力资本等)的初始状态、配置效率及动态变迁，经济... 详细信息

一、广东经济增长的影响因素国内外学者已对经济增长的源泉、路径作出了有益的探索和研究。概括起来，大家一致认为影响经济增长的主要4大因素是：要素禀赋(主要有劳动力、物质资本、人力资本等)的初始状态、配置效率及动态变迁，经济制度变革所导致的产权结构、产业结构的调整、市场化水平、外来资本的投向，技术进步和国家政策。不过，不同学者对我国经济高速增长的核心源泉有不同的看法。

关键词：经济增长影响因素路径选择竞争优势广东赖和经济高速增长市场化水平要素禀赋物质资本初始状态人力资本配置效率产权结构制度变革产业结构外来资本国家政策技术进步国内外劳动力学者投向

Modified electronic structure and enhanced hydroxyl adsorption make quaternary Pt-based nanosheets efficient anode electrocatalysts for formic acid-/alcohol-air fuel cells

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Journal of Energy Chemistry 2024年第5期92卷 142-150页

作者： Fengling Zhao Qiang Yuan Siyang Nie Liang Wu xun Wang State-Local Joint Laboratory for Comprehensive Utilization of Biomass Center for R&D of Fine ChemicalsCollege of Chemistry and Chemical EngineeringGuizhou UniversityGuiyang 550025GuizhouChina Key Lab of Organic Optoelectronics&Molecular Engineering Tsinghua UniversityBeijing 100084China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Surface/interface engineering of a multimetallic nanostructure with diverse electrocatalytic properties for direct liquid fuel cells is desirable yet ***,using visible light,a class of quaternary Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)ultrathin nanosheets is fabricated and used as high-performance anode electrocatalysts for formic acid-/alcohol-air fuel *** modified electronic structure of Pt,enhanced hydroxyl adsorption,and abundant exterior defects afford Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C high intrinsic anodic electrocatalytic activity to boost the power densities of direct formic acid-/methanol-/ethanol-/ethylene glycol-/glycerol-air fuel cells,and the corresponding peak power density of Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C is respectively 129.7,142.3,105.4,124.3,and 128.0 mW cm^(-2),considerably outperforming Pt/*** in situ Fourier transform infrared reflection spectroscopy reveals that formic acid oxidation on Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C occurs via a CO_(2)-free direct *** functional theory calculations show that the presence of Ag,Bi,and Te in Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)suppresses CO^(*)formation while optimizing dehydrogenation steps and synergistic effect and modified Pt effectively enhance H_(2)O dissociation to improve electrocatalytic *** synthesis strategy can be extended to 43 other types of ultrathin multimetallic nanosheets(from ternary to octonary nanosheets),and efficiently capture precious metals(i.e.,Pd,Pt,Rh,Ru,Au,and Ag)from different water sources.

关键词： Pt-based nanosheets Modifiedelectronic structure Enhanced hydroxyl adsorption Formicacidand alcohol oxidation Direct liquid fuel cells

Simultaneously enhanced electrochemical performance and air stability of Ni-rich cathode with a modified washing process

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Rare Metals 2024年第1期43卷 87-97页

作者： Ben-Rui Hu Ying-Yi Yuan Yu-Cheng Wang xun-Hui Xiong School of Environment and Energy Guangdong Provincial Key Laboratory of Advanced Energy Storage MaterialsSouth China University of TechnologyGuangzhou 510640China

Water washing has been regarded as one of the most effective strategies to remove surface residual lithium of nickel-rich layered oxides for lithium-ion batteries(LIBs).However,the loss of lattice lithium during the water washing process deteriorates the electrochemical performances and air ***,washing the LiNi_(0.90)Co_(0.05)Al_(0.02)O_(2)(NCA) with ammonium dihydrogen phosphate(NH_(4)H_(2)PO_(4)) solution has been proposed to simultaneously enhance electrochemical performances and air stability,in which in-situ generated Li_(3)PO_(4) coating layer on surface of NCA can suppress the loss of lattice ***,as a fast ionic conductor,Li_(3)PO_(4) coating layer on NCA can prevent the direct contact with electrolyte/*** a result,the NH_(4)H_(2)PO_(4) solution washed NCA cathode can deliver a high capacity of131.9 mAh·g^(-1) at 10.0C rate as well as impressive cycle stability with a capacity retention of 83.1% after 100 cycles at 1.0C,much higher than those of water washed NCA(WS-NCA) *** exposed in air for 7 days,the NH_(4)H_(2)PO_(4) solution washed NCA electrode can more effectively maintain the structural integrity as well as the electrochemical performances than water-washed *** work provides a simple and effective approach to enhance the cycle stability and air stability of Nickel-rich cathode materials.

关键词： Layered Ni-rich cathode Residual lithium Li_(3)PO_(4)coating Rate performance Air stability

Relationship Between Variation in Activities of Key Enzymes Related to Starch Synthesis During Grain Filling Period and Quality of Eating and Cooking in Rice

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Rice science 2006年第1期13卷 43-50页

作者： SHEN Peng QIAN Chun-rong JIY zheng-xun Luo Qiu-xiang JIY Xue-yong Agricultural College Northeast Agricultural University Harbin 150030 China

Four japonica rice varieties with significant differences in quality of eating and cooking were used in the experiment. The varieties showed differences in amylose and amylopectin contents at different grain filling stages, which were attributed to the accumulative speed of starch at different grain filling stages. During grain filling period, the varieties had no difference in the time when the activities of ADPglocose pyrophosphorylase （AGPP） and soluble starch synthesis （SSS） reached a maximum, but had difference in the time when the activity of starch branching enzyme （SBE） reached a maximum, in which the inferior quality varieties were earlier than the high quality ones, and high quality varieties still kept high enzyme activities at the late stage of grain filling. The correlation and correlative degree between AGPP, SSS, SBE and amylose content, amylopectin content, taste meter value, and RVA properties varied with the different stages of grain filling. The correlation between SSS activity and taste meter value was not significant during the whole period of grain filling, but the activities of AGPP and SBE had significant or highly significant correlation with taste meter value. It was helpful for improving quality of eating and cooking of japonica rice to use the materials with low enzyme activity at the early stage of grain filling or high enzyme activity at the late stage as parents.

关键词： japonica rice grain filling starch synthesis enzymes cooking quality eating quality

我国商业银行效率结构与竞争力研究——基于两步DEA与主成份旋转法的实证分析

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暨南学报（哲学社会科学版） 2007年第3期29卷 29-37页

作者：谭政勋王聪暨南大学珠海学院广东珠海519070 暨南大学经济学院广东广州510632

在论证银行效率和竞争力关系的基础上,利用两步DEA与多变量综合的主成份旋转法对我国商业银行的效率结构和竞争力进行了实证研究。1966-2003年间,我国商业银行总经济效率、规模效率和技术效率在波动中上升。配置效率和规模效率对总经济... 详细信息

在论证银行效率和竞争力关系的基础上,利用两步DEA与多变量综合的主成份旋转法对我国商业银行的效率结构和竞争力进行了实证研究。1966-2003年间,我国商业银行总经济效率、规模效率和技术效率在波动中上升。配置效率和规模效率对总经济效率影响较大,绝大多数银行的纯技术校率相差很小,因而对总经济效率的影响不大。无论是效率水平还是竞争力的排名,股份制银行总体上比国有银行要靠前,配置效率、公司治理制度对排名产生了重要影响。招商银行、浦发银行和民生银行的排名始终靠前,华夏银行和兴业银行的潜在竞争力和综合竞争力比现实竞争力和总经济效率的排名大大提前,而中信实业银行刚好相反,建设银行和中国银行的现实竞争力比总经济效率的排名靠前。

关键词：效率结构竞争力两步DEA 主成份旋转法

泛珠江三角洲经济结构差异、成因及合作策略研究

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中国工业经济 2005年第7期 65-72页

作者：王聪谭政勋暨南大学经济学院广东广州510632 暨南大学珠海学院广东珠海519070

本文以泛珠江三角洲区域①内具有代表性的广东、湖南、贵州三省为研究对象,采用可变弹性生产函数法和全要素生产率法分析三省的经济差距及其原因。实证分析表明,广东省率先进行改革开放的制度变革及由此吸收了更多的投资、形成了更多的... 详细信息

本文以泛珠江三角洲区域①内具有代表性的广东、湖南、贵州三省为研究对象,采用可变弹性生产函数法和全要素生产率法分析三省的经济差距及其原因。实证分析表明,广东省率先进行改革开放的制度变革及由此吸收了更多的投资、形成了更多的固定资本是拉开经济差距的关键因素。文章最后在总结广东经济发展路径依赖的基础上,提出了泛珠江三角洲区域经济合作竞争的路径选择:发挥比较优势,形成竞争优势。

关键词：区域经济差距及成因比较优势竞争优势