139 research outputs found

    大陆新三板市场与台湾兴柜市场资本配置效率比较研究

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    近几年大陆新三板市场实现了跨越式发展,但仍面临许多亟待解决的问题和困境。明确新三板的市场定位并进一步提升其资本配置效率,是关系到新三板市场发展成效的重要课题。本文采用Jeffrey Wurgler(2000)资本配置效率模型对大陆新三板市场和台湾兴柜市场的资本配置效率进行实证比较,并从市场定位、准入门槛、做市商制度和投机氛围等方面分析二者效率差异的主要原因。在此基础上,结合大陆新三板市场发展中存在的问题,对如何进一步强化其市场定位和完善相应的制度设计提出政策建议。海峡博士后交流资助计划;;中国博士后科学基金面上项目一等资助(2016M600497);;教育部人文社会科学重点基地重大项目“新形势下两岸经济融合发展的动力机制研究”(16JJD790036

    双蒲散对慢性萎缩性胃炎大鼠胃黏膜细胞TGF-β1/Smad3信号通路的影响

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    目的 :观察双蒲散对慢性萎缩性胃炎的治疗作用以及胃黏膜细胞TGF/Smad信号通路的影响。方法 :40只SD大鼠随机分为正常组、模型组、双蒲散组和维酶素组,每组10只。采用N-甲基-N`-硝基-N-亚硝基胍(MNNG)方法复制慢性萎缩性胃炎大鼠模型,正常组不处理,模型组只造模不干预,其余两组造模16周后分别灌胃双蒲散和维酶素4周。光镜观察胃黏膜组织病理学,酶联免疫吸附法测定胃黏膜组织Bcl-2、P53、PCNA、Ag-NORs、EGF、TGF-β1与Smad3蛋白的表达。结果 :与正常组比较,模型组大鼠胃黏膜组织Bcl-2、P53、PCNA、Ag-NORs、EGF、TGF-β1的表达皆明显升高,Smad3皆显著下降(P<0.05);与模型组比较,双蒲散组大鼠胃黏膜组织Bcl-2、P53、PCNA、Ag-NORs、EGF、TGF-β1的表达皆明显下降,Smad3皆显著升高(P<0.05),其效应显著高于维酶素组。结论 :双蒲散可通过调节TGF-β1/Smad3信号通路调节慢性萎缩性胃炎大鼠胃黏膜细胞的增殖和凋亡,抑制胃黏膜细胞的异型增生,阻断慢性萎缩性胃炎向胃癌前病变发展。国家自然科学基金项目(81260556);; 江西省自然科学基金项目(20131512040019

    A New Mathematics Model of the Temperature Programmed Analysis Technology

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    以表面作用包括表面吸/脱附以及表面反应本征速率方程为基础,提出新的程序升温分析技术(TPAT)的数学模型。与经典的理论模型相比,这种新的TPAT理论模型更接近实际的程序升温分析实验过程。设计和进行特定催化剂的TPd、TPr及TPO实验,得到相应的程序升温谱图,采用新的TPAT理论模型模拟上述谱图,计算出相应的表面作用活化能等重要热力学参数。结果表明,新的理论模型具有良好的模拟性能,平均相对误差(Ard)小于1%。Based on the surface effect including surface adsorption/desorption and intrinsic kinetics rate equation,a new mathematical model of the temperature programmed analysis technology was proposed.This model is different from the classical TPAT theory models,which indicates much more coincidence with the actual reactions than other models.TPAT(TPD,TPR and TPO) experiments were designed and carried out to receive their profiles.Based on these profiles of TPAT and the simulated experiments,the novel theory model was designed and the thermodynamics parameters(such as activation energy,etc.) were deduced and calculated by this model.The results show that this model has excellent simulation with the actual experiments,and the average relative errors are easily controlled less than 1%

    Freestanding palladium nanosheets with plasmonic and catalytic properties

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    通讯作者地址: Huang, XQ (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 3. Xiamen Univ, Dept Phys, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] metal films can exhibit quantum size and surface effects that give rise to unique physical and chemical properties(1-7). Metal films containing just a few layers of atoms can be fabricated on substrates using deposition techniques(7), but the production of freestanding ultrathin structures remains a significant challenge. Here we report the facile synthesis of freestanding hexagonal palladium nanosheets that are less than 10 atomic layers thick, using carbon monoxide as a surface confining agent. The as-prepared nanosheets are blue in colour and exhibit a well-defined but tunable surface plasmon resonance peak in the near-infrared region. The combination of photothermal stability and biocompatibility makes palladium nanosheets promising candidates for photothermal therapy. The nanosheets also exhibit electrocatalytic activity for the oxidation of formic acid that is 2.5 times greater than that of commercial palladium black catalyst.NSF of China 20925103 20871100 20721001 20703032 MOST of China 2009CB930703 2011CB932403 Fok Ying Tung Education Foundation 121011 NSF of Fujian 2009J06005 Key Scientific Project of Fujian Province 2009HZ0002-

    闽南文化研究国际笔谈会论点选载

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    2013年12月21日,由闽南师范大学闽南文化研究院主办的“2013闽南文化研究国际笔谈会“在国际学术交流中心召开。来自海峡两岸及日本、新加坡等国家的闽南文化研究方面的专家、学者二十余人出席了会议。会议围绕着闽南文化的内涵、外延及特征,闽南文化的当代价值与社会功能,闽南文化研究的理论与方法,闽南文化的跨文化阐释,闽南文化的世界性及其意义,闽南文化与两岸交流,闽南文化的生态保护,闽南文化学科建设与人才培养等议题展开了深入的研讨,言简意赅,探幽发微,对当下闽南文化理论研究势必产生积极的影响。本期节录专家们的精彩发言,以飨读者,也希望由此来带动和促进闽南文化研究的进一步升华

    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

    Genomic Insights into the Formation of Human Populations in East Asia

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    厦门大学人类学研究所、厦门大学生命科学学院细胞应激生物学国家重点实验室王传超教授课题组与哈佛医学院David Reich教授团队合作,联合全球43个单位的85位共同作者组成的国际合作团队通过古DNA精细解析东亚人群形成历史。研究人员利用古DNA数据检验了东亚地区农业和语言共扩散理论,综合考古学、语言学等证据,该研究系统性地重构了东亚人群的形成、迁徙和混合历史。这是目前国内开展的东亚地区最大规模的考古基因组学研究,此次所报道的东亚地区古人基因组样本量是以往国内研究机构所发表的样本量总和的两倍,改变了东亚地区尤其是中国境内考古基因组学研究长期滞后的局面。 该研究是由王传超教授团队与哈佛医学院(David Reich教授)、德国马普人类历史科学研究所(Johannes Krause教授)、复旦大学现代人类学教育部重点实验室(李辉教授和金力院士)、维也纳大学进化人类学系(Ron Pinhasi副教授)、南洋理工大学人文学院(Hui-Yuan Yeh助理教授)、俄罗斯远东联邦大学科学博物馆(Alexander N Popov研究员)、西安交通大学(张虎勤教授)、蒙古国国家博物馆研究中心、乌兰巴托国立大学考古系、华盛顿大学人类学系、台湾成功大学考古所、加州大学人类学系等全球43个单位的85位共同作者组成的国际合作团队联合完成的。厦门大学人类学研究所、厦门大学生命科学学院细胞应激生物学国家重点实验室为论文第一完成单位。厦门大学人类学研究所韦兰海副教授、胡荣助理教授、郭健新博士后、何光林博士后和杨晓敏硕士参与了研究工作。The deep population history of East Asia remains poorly understood due to a lack of ancient DNA data and sparse sampling of present-day people1,2. We report genome-wide data from 166 East Asians dating to 6000 BCE-1000 CE and 46 present-day groups. Hunter-gatherers from Japan, the Amur River Basin, and people of Neolithic and Iron Age Taiwan and the Tibetan plateau are linked by a deeply-splitting lineage likely reflecting a Late Pleistocene coastal migration. We follow Holocene expansions from four regions. First, hunter-gatherers of Mongolia and the Amur River Basin have ancestry shared by Mongolic and Tungusic language speakers but do not carry West Liao River farmer ancestry contradicting theories that their expansion spread these proto-languages. Second, Yellow River Basin farmers at ~3000 BCE likely spread Sino-Tibetan languages as their ancestry dispersed both to Tibet where it forms up ~84% to some groups and to the Central Plain where it contributed ~59-84% to Han Chinese. Third, people from Taiwan ~1300 BCE to 800 CE derived ~75% ancestry from a lineage also common in modern Austronesian, Tai-Kadai and Austroasiatic speakers likely deriving from Yangtze River Valley farmers; ancient Taiwan people also derived ~25% ancestry from a northern lineage related to but different from Yellow River farmers implying an additional north-to-south expansion. Fourth, Yamnaya Steppe pastoralist ancestry arrived in western Mongolia after ~3000 BCE but was displaced by previously established lineages even while it persisted in western China as expected if it spread the ancestor of Tocharian Indo-European languages. Two later gene flows affected western Mongolia: after ~2000 BCE migrants with Yamnaya and European farmer ancestry, and episodic impacts of later groups with ancestry from Turan.We thank David Anthony, Ofer Bar-Yosef, Katherine Brunson, Rowan Flad, Pavel Flegontov,Qiaomei Fu, Wolfgang Haak, Iosif Lazaridis, Mark Lipson, Iain Mathieson, Richard Meadow,Inigo Olalde, Nick Patterson, Pontus Skoglund, Dan Xu, and the four reviewers for valuable comments. We thank Naruya Saitou and the Asian DNA Repository Consortium for sharing genotype data from present-day Japanese groups. We thank Toyohiro Nishimoto and Takashi Fujisawa from the Rebun Town Board of Education for sharing the Funadomari Jomon samples, and Hideyo Tanaka and Watru Nagahara from the Archeological Center of Chiba City who are excavators of the Rokutsu Jomon site. The excavations at Boisman-2 site (Boisman culture), the Pospelovo-1 site (Yankovsky culture), and the Roshino-4 site (Heishui Mohe culture) were funded by the Far Eastern Federal University and the Institute of History,Archaeology and Ethnology Far Eastern Branch of the Russian Academy of Sciences; research on Pospelovo-1 is funded by RFBR project number 18-09-40101. C.C.W was funded by the Max Planck Society, the National Natural Science Foundation of China (NSFC 31801040), the Nanqiang Outstanding Young Talents Program of Xiamen University (X2123302), the Major project of National Social Science Foundation of China (20&ZD248), a European Research Council (ERC) grant to Dan Xu (ERC-2019-ADG-883700-TRAM) and Fundamental Research Funds for the Central Universities (ZK1144). O.B. and Y.B. were funded by Russian Scientific Foundation grant 17-14-01345. H.M. was supported by the grant JSPS 16H02527. M.R. and C.C.W received funding from the ERC under the European Union’s Horizon 2020 research and innovation program (grant No 646612) to M.R. The research of C.S. is supported 30 by the Calleva Foundation and the Human Origins Research Fund. H.L was funded NSFC (91731303, 31671297), B&R International Joint Laboratory of Eurasian Anthropology (18490750300). J.K. was funded by DFG grant KR 4015/1-1, the Baden Württemberg Foundation, and the Max Planck Institute. Accelerator Mass Spectrometry radiocarbon dating work was supported by the National Science Foundation (NSF) (BCS-1460369) to D.J.K. and B.J.C. D.R. was funded by NSF grant BCS-1032255, NIH (NIGMS) grant GM100233, the Paul M. Allen Frontiers Group, John Templeton Foundation grant 61220, a gift from Jean-Francois Clin, and the Howard Hughes Medical Institute. 该研究得到了国家自然科学基金“中国东南各族群的遗传混合”、国家社科基金重大项目“多学科视角下的南岛语族的起源和形成研究”、厦门大学南强青年拔尖人才支持计划A类、中央高校基本科研业务费等资助

    锑辅助生长的砷化铟/砷化镓量子点太阳电池的制作方法

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    &nbsp;一种锑辅助生长的砷化铟/砷化镓量子点太阳电池的制作方法,包括如下步骤:步骤1:选择一衬底;步骤2:在衬底上依次生长n+型GaAs层和本征GaAs缓冲层;步骤3:在本征GaAs缓冲层上沉积一锑层;步骤4:在锑层上依次生长多个周期的量子点结构、本征GaAs层、p型GaAs层、p+型GaAs层、p+型Al0.8Ga0.2As层和p+型GaAs层;步骤5:在p+型GaAs层上蒸发上金属电极;步骤6:刻蚀上金属电极,使上金属电极形成网状;步骤7:在网状上金属电极上及裸露的p+型GaAs层上生长减反层;步骤8:剥离减反层,使上金属电极裸露;步骤9:在衬底的下表面制作下金属电极,形成电池组件;步骤10:对电池组件进行封装,完成太阳电池的制作
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