20 research outputs found

    基于频繁关键字共现的诗词风格分类模型研究

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    为了提高宋词文档分类的精确性,本文在广泛采用的向量空间模型(Vector space model ,VSM) 的基础上,对分类 算法中使用的特征项做了相应的修改,提出了频繁关键字共现的概念. 在实验过程中,首先提取了宋词语料库中的关键 字,再利用发现关联规则的Apriori 算法发现分类时所需要的频繁关键字共现,最后结合关键字和频繁关键字共现,利用最邻近算法( KNN) 对宋词文档进行风格分类. 实验结果发现,结合了频繁关键字共现的VSM 可以提高对宋词风格分类的准确度. 可见,频繁关键字共现确实提供了风格分类中所需的更多信息.国家自然科学基金(60373080

    Physiological responses of three cultivar seedlings of Bougainvillea under drought stress

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    该研究对勤花三角梅(Bougainvillea buttiana Miss Manila')、樱花三角梅(B.glabra Imperial; Delight')和金心鸳鸯三角梅(B.peruviana; Thimma')三个三角梅品种的幼苗进行人工干旱胁迫,分析了干旱胁迫对三角梅品种的外观形态和生理生化水平的影响,探讨了不同品种三角梅对干旱胁迫的; 适应能力。结果表明:随着干旱时间的延长,三角梅品种的叶片出现下垂、皱缩、变黄、脱落,最后植株死亡;过氧化物酶POD活性先升高后降低,而超氧化物歧; 化酶SOD活性则逐渐降低,降低速度因品种而异;qP值降低、qN值升高、PSⅡ反应中心光化学效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)均呈现; 降低。该研究结果为三角梅的栽培应用和品种选择提供了依据。Seedlings of Bougainvillea buttiana Miss Manila', B.glabra Imperial; Delight' and B.peruviana Thimma' were treated to study the physiological; responses under drought stress.The results showed that the plant leaves; began to droop, gradually shrink, yellow in color, and fell off, all of; the treatment seedlings died finally under the long drought.The results; showed that the peroxidase activities(POD) were increased at beginning,; and decreased finally, while the superoxide dismutase(SOD) activities; were gradual decreased, but the reduction rates were different in the; three cultivar seedlings.The research on chlorophyll fluorescence; parameters showed that qP value was decreased, while qN value was; increased, and the photochemical efficiency of PSⅡreaction center(Fv/Fm); and potential activity of PS Ⅱ(Fv/Fo) were decreased under drought; stress.This study provides information for breeding application and; choosing ulltivars of Bougainvillea.厦门市科学技术局资助项

    Preparation of Co-YSZ/HAp Nano-composite Coating on Ti Substrate by Electrochemical Method

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    采用复合电沉积和电泳沉积两步法在钛基体上制备了Co-YSZ/HAp纳米复合涂层,与只采用电泳沉积法在钛基体上制备纳米HAp单一涂层进行了比较研究.采用场发射扫描电镜、X射线衍射和能量散射谱对复合涂层的微观形貌,纳米HAp外层表面形貌,晶相,复合涂层的断面形貌及元素组成分布进行分析研究.通过粘结-拉伸实验测定了涂层与基体的结合强度,结果表明,Co-YSZ/HAp纳米复合涂层与钛基体的结合强度明显高于纳米HAp单一涂层与钛基体的结合强度,说明复合涂层具有更好的力学性能.Co-YSZ/HAp nano-composite coating and nano-HAp single coating were deposited on Ti substrate using the combination of electrocodeposition and electrophoretic deposition, and electrophoretic depositions, respectively. Surface and cross section morphologies of the coatings were observed by scanning electron microscope. Element distribution and crystal phase of the coatings were analyzed by energy dispersive spectrum and X-ray diffraction. The adhesive strength of the coating and Ti substrate was determined by shear strength testing. The results indicate that the adhesive strength of Co-YSZ/HAp nano-composite coating and Ti substrate is higher than that of nano-HAp single coating and Ti substrate. It shows that Co-YSZ as an interlayer reduces the mismatch of the thermal expansion coefficients between HAp and titanium and Co-YSZ/HAp nano-composite coating has better mechanical properties.国家自然科学基金(20573086,200273055);; 福建省自然科学基金(E0210004)资助项

    Preparation of Co-YSZ/HAp nano-composite coating on Ti substrate by electrochemical method

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    Co-YSZ/HAp nano-composite coating and nano-HAp single coating were deposited on Ti substrate using the combination of electrocodeposition and electrophoretic deposition, and electrophoretic depositions, respectively. Surface and cross section morphologies of the coatings were observed by scanning electron microscope. Element distribution and crystal phase of the coatings were analyzed by energy dispersive spectrum and X-ray diffraction. The adhesive strength of the coating and Ti substrate was determined by shear strength testing. The results indicate that the adhesive strength of Co-YSZ/HAp nano-composite coating and Ti substrate is higher than that of nano-HAp single coating and Ti substrate. It shows that Co-YSZ as an interlayer reduces the mismatch of the thermal expansion coefficients between HAp and titanium and Co-YSZ/HAp nano-composite coating has better mechanical properties

    中国物理海洋学研究70年:发展历程、学术成就概览

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    本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军

    Frequent Keyword Concurrence-Based Vector Space Model for Chinese Poetry Style Analysis

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    摘要: 为了提高宋词文档分类的精确性 ,本文在广泛采用的向量空间模型(Vector space model ,VSM)的基础上 ,对分类算法中使用的特征项做了相应的修改 ,提出了频繁关键字共现的概念.在实验过程中 ,首先提取了宋词语料库中的关键字 ,再利用发现关联规则的 Apriori算法发现分类时所需要的频繁关键字共现 ,最后结合关键字和频繁关键字共现 ,利用 最邻近算法( KNN)对宋词文档进行风格分类.实验结果发现 ,结合了频繁关键字共现的 VSM可以提高对宋词风格分类的准确度.可见 ,频繁关键字共现确实提供了风格分类中所需的更多信息. Abstract : The paper presented a new concept called f requent keyword concurrence-based vector space model ( FKC2VSM) . FKC- VSM had proved to be effective in promoting the accuracy of Chinese poems' style classification. Frequent keyword concurrences couldbe found out by one of data mining technologies called Apriori algorithm. After detecting f requent keyword concurrences ,we used KNN algorithm to classify different poems ’ style. Combining keywords and f requent keyword concurrences ,KNN algorithm performed better than that without f requent keyword concurrences. In a word ,af ter the int roduction of FKC-VSM ,the result s of the experiments improved.基金项目:国家自然科学基金(60373080)资

    CuHY分子筛中铜离子的分布与吸附脱硫性能

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    采用等体积浸渍法制备具有不同Cu担载量的CuHY分子筛吸附剂.用X射线衍射(XRD)、比表面积(BET)和氨程序升温脱附(NH3-TPD)技术对分子筛吸附剂进行了表征,并测定了CuHY分子筛吸附剂在含二苯并噻吩(DBT)模拟柴油中的吸附脱硫性能;通过多晶XRD确定了Cu2+在Cu8HY分子筛笼内的结构与分布.实验结果表明,分子筛的骨架结构没有发生改变,部分Cu2+进入Y型分子筛笼内,分子筛样品强酸中心有所减少,中强酸中心有所增加;进入Y型分子筛笼内的Cu2+,一部分处于β笼的SⅠ′位,另一部分位于分子筛超笼中的SⅢ位上,并与笼内的水分子配位.处于超笼中的SⅢ位Cu2+对模拟柴油中的DBT分子具有吸附作用,是吸附脱硫的中心.而当模拟柴油中存在萘时,与DBT分子会产生竞争吸附

    CuHY分子筛中铜离子的分布与吸附脱硫性能

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    采用等体积浸渍法制备具有不同Cu担载量的CuHY分子筛吸附剂.用X射线衍射(XRD)、比表面积(BET)和氨程序升温脱附(NH3-TPD)技术对分子筛吸附剂进行了表征,并测定了CuHY分子筛吸附剂在含二苯并噻吩(DBT)模拟柴油中的吸附脱硫性能;通过多晶XRD确定了Cu2+在Cu8HY分子筛笼内的结构与分布.实验结果表明,分子筛的骨架结构没有发生改变,部分Cu2+进入Y型分子筛笼内,分子筛样品强酸中心有所减少,中强酸中心有所增加;进入Y型分子筛笼内的Cu2+,一部分处于β笼的SⅠ′位,另一部分位于分子筛超笼中的SⅢ位上,并与笼内的水分子配位.处于超笼中的SⅢ位Cu2+对模拟柴油中的DBT分子具有吸附作用,是吸附脱硫的中心.而当模拟柴油中存在萘时,与DBT分子会产生竞争吸附

    Preparation of YSZ/HAp nano-composite coating on Ti alloy substrate by electrophoretic deposition

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    [中文文摘]采用电泳沉积法在钛合金基体上制备了YSZ/HAp纳米复合涂层,用场发射扫描电镜、X射线衍射和能量散射谱对复合涂层HAp外层的表面形貌和晶相、复合涂层的断面形貌及元素组成分布进行分析研究,通过粘结-拉伸实验测定了涂层与基体的结合强度。结果表明YSZ/HAp纳米复合涂层与钛合金基体的结合强度明显高于HAp单一涂层与钛合金基体的结合强度,说明YSZ/HAp的复合缓和了HAp涂层与钛合金基体之间的热膨胀系数失配现象,改善了涂层与基体之间的结合。[英文文摘]YSZ/HAp nano-composite coating and HAp single coating were deposited on Ti alloy substrate by electrophoretic deposition.Surface and cross section morphologies of the composite coating were observed by scanning electron microscope.Element distribution and crystal phase of the composite coating were analyzed by energy dispersive spectrum and X-ray diffraction.The bonding strength between coating and Ti alloy substrate was tested by shear strength testing experiment.The results indicate that the bonding strength of YSZ/ HAp composite coating is higher than that of HAp single coating. It shows that YSZas an interlayer reduces the mismatch of thermal expansion coefficients between HAp coating and substrate and enhances the bonding strength of the HAp coating to the Ti alloy substrate.国家自然科学基金资助项目(20573086,200273055); 福建省自然科学基金资助项目(E0210004)

    CuHY分子筛中铜离子的分布与吸附脱硫性能

    No full text
    采用等体积浸渍法制备具有不同Cu担载量的CuHY分子筛吸附剂.用X射线衍射(XRD)、比表面积(BET)和氨程序升温脱附(NH3-TPD)技术对分子筛吸附剂进行了表征,并测定了CuHY分子筛吸附剂在含二苯并噻吩(DBT)模拟柴油中的吸附脱硫性能;通过多晶XRD确定了Cu2+在Cu8HY分子筛笼内的结构与分布.实验结果表明,分子筛的骨架结构没有发生改变,部分Cu2+进入Y型分子筛笼内,分子筛样品强酸中心有所减少,中强酸中心有所增加;进入Y型分子筛笼内的Cu2+,一部分处于β笼的SⅠ′位,另一部分位于分子筛超笼中的SⅢ位上,并与笼内的水分子配位.处于超笼中的SⅢ位Cu2+对模拟柴油中的DBT分子具有吸附作用,是吸附脱硫的中心.而当模拟柴油中存在萘时,与DBT分子会产生竞争吸附
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