The Study of China Open-end Fund's Net Purchase Rate based on Investors' Choice

开放式基金因为发行份额不固定，随时可能被投资者申购或赎回，因此基金的管理人在运营过程中须要面对投资者申购或赎回基金份额带来的资金流动。本文用净申购率来描述这种资金流动变化，资金流动的背后是投资者根据市场信息对基金的选择，基于市场公开信息，本文将从影响投资者选择的基金收益率、基金分红、基金规模以及市场行情表现等角度来研究净申购率。 我们选取2006年第一季度到2011年第四季度的275只偏股类基金作为研究样本，并将全样本时期划分为股市大涨阶段、大跌阶段和平衡阶段，分别在全样本时期和各个阶段对净申购率模型进行估计。我们发现，在全样本时期中基金净申购率与本期收益率、上期基金规模之间负相关，与上期净...Because the share issue can be either purchased or redeemed at any time, open-end Fund is not fixed. The fund managers must face the problem of fund flows brought by investors’ purchase or redemption choice in the fund’s operation. In this paper, we use the net purchase rate as explained variable to describe the flow of fund capital change. Since capital flow stands for the investors’ fund selecti...学位：金融硕士院系专业：王亚南经济研究院_金融学(含保险学)学号：2772009115240

城市郊区外生型农村城市化研究———厦门市禾山镇的案例分析

禾山镇的城市化方式,基本上属于由外部经济力量推进的郊区外生型农村城市化类型, 这是一种具有较高效率的高起点的城市化模式, 但是, 由于自主工业化机会成本太高, 缺乏内在的经济推动力,城市化各要素发展不平衡,相应出现了一些问题。本文对外生型农村城市化过程中出现的问题进行研究,并提出相应的政策建议

导线张力对输电杆塔安全性和经济性的影响研究

针对使用广泛的500 kV架空输电线路，分别研究了在轻、中、重冰区，由断线及不均匀覆冰引起的导线张力对输电杆塔安全性和经济性的影响。研究表明：导线张力增加0～20%，若保持杆塔杆件规格不变，悬垂塔的超限杆件比例为0～51%，耐张塔的超限杆件比例为0～4%；若增大杆塔杆件规格以保证安全，悬垂塔的塔重增加0～28%，耐张塔的塔重增加0～5%；覆冰越厚，由断线引起的导线张力对杆塔影响越小，由不均匀覆冰引起的导线张力对杆塔影响越大；导线张力主要影响悬垂塔横担上、下平面交叉材、塔身主斜材等杆塔杆件。因此，对重要输电线路和输电线路重要区段，推荐重点加强悬垂塔的防串倒及抗冰能力。研究结论对工程实践具有一定的指导意义

福建城市化发展战略博士笔谈

2003年5月,“福建省博士创业促进会”在福州举办了福建省城市发展战略“博士月谈”,与会者主要是省内高校和科研单位的专家、博士。会上,大家用书面发表意见,畅所欲言,崇论宏议。本刊精选部分意见,以飨读者。相信这些意见对福建城市化问题研究的深化将起到积极的推动作用

Room-temperature quantum interference in single perovskite quantum dot junctions

钙钛矿材料由于其高量子产率、载流子迁移率和独特的光致发光特性而在光电材料领域存在诸多潜在的重要应用。研究钙钛矿材料在纳米尺度下电荷输运的独特尺寸效应对钙钛矿光电器件的设计和开发具有重要的指导意义。洪文晶教授课题组基于机械可控裂结技术自主研发了具有皮米级位移调控灵敏度和飞安级电学测量精度的精密科学仪器，对南开大学李跃龙副教授团队合成的钙钛矿量子点进行了深入表征，研究工作成功将量子干涉的研究体系拓展至在光电领域具有重要应用的钙钛矿材料领域，为未来制备基于量子干涉效应的新型钙钛矿器件提供了一种全新的思路。 这一跨学科国际合作研究工作是在化学化工学院洪文晶教授、英国Lancaster 大学物理系Colin J. Lambert教授以及南开大学电子信息与光电工程学院李跃龙副教授的共同指导下完成的。化工系硕士研究生郑海宁、Lancaster University大学Songjun Hou博士、南开大学硕士研究生辛晨光为论文第一作者。博士后林禄春，博士研究生谭志冰、郑珏婷，硕士研究生蒋枫、张珑漪，本科生何文翔、李庆民等参与了论文的研究工作。刘俊扬特任副研究员、师佳副教授和萨本栋微纳米研究院杨扬副教授也参与了部分指导工作。The studies of quantum interference effects through bulk perovskite materials at the Ångstrom scale still remain as a major challenge. Herein, we provide the observation of roomtemperature quantum interference effects in metal halide perovskite quantum dots (QDs) using the mechanically controllable break junction technique. Single-QD conductance measurements reveal that there are multiple conductance peaks for the CH3NH3PbBr3 and CH3NH3PbBr2.15Cl0.85 QDs, whose displacement distributions match the lattice constant of QDs, suggesting that the gold electrodes slide through different lattice sites of the QD via Auhalogen coupling. We also observe a distinct conductance ‘jump’ at the end of the sliding process, which is further evidence that quantum interference effects dominate charge transport in these single-QD junctions. This conductance ‘jump’ is also confirmed by our theoretical calculations utilizing density functional theory combined with quantum transport theory. Our measurements and theory create a pathway to exploit quantum interference effects in quantum-controlled perovskite materials.This work was supported by the National Key R&D Program of China (2017YFA0204902, 2014DFE60170, 2018YFB1500105), the National Natural Science Foundation of China (Nos. 21673195, 21503179, 21490573, 61674084, 61874167), the Open Fund of the Key Laboratory of Optical Information Science & Technology (Nankai University) of China, the Fundamental Research Funds for the Central Universities of China (63181321, 63191414, 96173224), and the 111 Project (B16027), the Tianjin Natural Science Foundation (17JCYBJC41400), FET Open project 767187—QuIET, the EU project BAC-TO-FUEL and the UK EPSRC projects EP/N017188/1, EP/M014452/1. 该工作得到国家重点研发计划课题（2017YFA0204902）、国家自然科学基金（21673195、21503179、21490573）、厦门大学“人工智能分析引擎”双一流重大专项等项目的资助，也得到了固体表面物理化学国家重点实验室、能源材料化学协同创新中心的支持

<title>A Research on the Employment Problem of Suburban Farmers in the Course of Passive Urbanization--An Empirical Study on the Problem of NonAgricultural Trend of Farmers in Heshan Town,Xiamen

在城市扩张过程中郊区农村属于被动加入城市化行列。由于郊区农业边际收益高,农民非农化水平相对滞后于城市的发展。城郊农民违章搭盖带来的收益,增加部分农民自愿待业的倾向。推进郊区农村城市化,需广辟农民非农化途径,鼓励农民发展第三产业,把处理农民违章建筑与允许农民集资建设"外来人员公寓"和农民的劳动就业联系起来,促进郊区农民特别是青年农民的就业。In the course of city expansion,the countryside is passively urbanized.Because of high margin profit from agriculture,the development of transforming farmers into nonfarmers is slower than the development of the city.The profit getting from the unruly building encourages some farmers to stay voluntarily unemployed.In order to urbanized the suburban countryside,we need to increase the ways of transforming farmers into nonfarmers,to encourage the farmers to develop the third industry,to connect the employment of farmers with the prohibition of unruly building and the permission of building"apartments for people from other provinces",in order to promote employment for suburban farmers,specially for young farmers..NULL

Inactivation of Scrippsiella trochoideacysts using hydroxyl radials

随着船舶压载水的转运,我国面临严重的外来入侵生物风险,其中部分赤潮藻形成的孢囊可成为赤潮的种源,严重危害近岸海洋环境,因而快速有效地杀灭赤潮藻孢; 囊至关重要。本文利用大气压强电离放电高效生成的羟基自由基(·OH),对典型赤潮藻锥状斯氏藻孢囊进行杀灭研究。采用萌发实验、SYTOX; Green荧光染色法确定·OH杀灭锥状斯氏藻孢囊的阈值和时间,扫描电子显微镜观察孢囊的形态变化。结果表明,·OH杀灭孢囊的CT阈值为0.49mg; ·min/L,时间为10s,·OH氧化降解孢囊体内叶绿素,破坏DNA,抑制萌发,具有其他方法无法比拟的优势。因此,·OH快速杀灭赤潮藻孢囊的新方; 法,对防控外来入侵生物引发的海洋赤潮灾害具有重要的作用。Resting cysts are largely formed during the red tide which may be; theseed bankof next harmful algal bloom.And the resting cysts are; resistant to normal physical and chemical treatments due to their thick; cyst walls. In this paper,the resting cysts of Scrippsiella trochoidea; were produced using N-limited medium.The resting cysts were inactivated; using hydroxyl radicals based on a strong ionization discharge.The; results showed that hydroxyl radicals could inactivate the resting cysts; effectively when the CT value was 0.49mg·min/L with a contact time of; 10s.Morphological changes were observed using scanning electron; microscope which showed that hydroxyl radicals could destroy the thick; cyst wall.After entering the cell,hydroxyl radicals may damage the; chlorophyll and DNA.Also,the germination rate decreased to zero.In; general,the·OH treatment can be applied to inactivate the resting cysts; of S.trochoideaand provide a new method to kill the harmful algal cysts; in ballast water.国家科技支撑计划项目; 国家重大科研仪器研制项目; 科技部创新人才推进计划重点领域创新团

Relationship of conversion rate of catalytic reaction to catalyst component contents

[中文文摘]针对三种不同物料连续流动催化反应系统:(1)MoVTeNbO/SiO_2用于丙烷选择氧化制丙烯醛反应;(2)KMoNi/SiO_2用于高硫合成气制甲硫醇反应;(3)MoNiP/Al_2O_3用于噻吩加氢脱硫反应。在各自的固定反应条件下,研究催化反应转化率与催化剂组分含量的关系,提出半经验表达式:x_A=1-exp[-G(w_i)],G(w_i)=。利用此式拟合上述3个催化反应系统的实验数据,平均相对偏差分别为1.97%,1.54%和1.42%,拟合精度较高,证明所提出的关系式是合理的,而且颇有普适性,可用于优化设计催化剂组分的含量。[英文文摘]Relationship of conversion to catalyst contents was studied for three different material catalytic reaction systems with continuous -flow of reactants as follows:(1) MoVTeNbO/SiO_2 catalysts for selective oxidation of propane to acrolein;(2) KMoNi/SiO_2 catalysts for methanethiol synthesis from high H_2S-containning synthesis gas;(3) MoNiP/Al_2O_3 catalysts for thiophene hydrodesulfurization. A semiempirical expression of relationship of conversion to catalyst contents was put forward and used to correlate the experimental data of the above reactions.Average relative deviation(ARD) are 1.97%,1.54%and 1.42% respectively. The high fitting precision indicates that the expression proposed is reasonable,widely applicable and can be used for optimizing component contents of catalysts.国家重点基础研究发展计划(973计划,2004CB217805); 福建省百千万人才工程(闽人办[2003]40号)

洛川黄土/古土壤中有机碳的分布特征及其与粘土矿物的相关性

系统测定了陕西洛川黑木沟黄土/古土壤的总有机碳及其主要组分(稳定有机碳、矿物保护有机碳和化学稳定有机碳)的含量,并对总有机碳与粘粒含量及粘土矿物含量的相关性进行了分析。结果表明:(1)各层古土壤的总有机碳含量均高于其下伏的黄土层(S4例外),而稳定有机碳、矿物保护有机碳以及化学稳定有机碳的平均含量在黄土与古土壤之间无明显差异;(2)黄土和古土壤中有机碳含量达到稳定所需要的时间不同,分别是140~250 ka和330~410ka;(3)总有机碳和化学稳定有机碳与粘粒呈正相关关系(相关系数r分别为0.46和0.54),它们与粉粒和细砂粒的相关性较差,这说明粘粒是土壤固定有机碳的重要组分;(4)高岭石与总有机碳和化学稳定有机碳的相关性比较明显(r分别为0.74和0.61),伊利石和蒙脱石与它们不相关或相关性较差。</p