Government Competition, Political Connections and the Performance of Private Firms in China

改革开放以来，中国民营企业获得了巨大的发展成就，民营经济成为国民经济的重要组成部分，深入研究中国民营企业绩效的影响因素不仅具有现实意义，更具有重要的实践意义。本文在地区竞争的背景下，分析民营企业政治联系对企业绩效的影响。财政分权和官员晋升激励带来的地区间政府竞争是中国民营化的重要原因，也成为分析中国民营企业政治联系以及民营企业绩效的重要的制度背景。关于政治联系对企业绩效的影响，“帮助之手”与“掠夺之手”尚存在争论。本文从地方间政府竞争这一重要的制度背景的角度，研究中国民营企业高管的政治联系与企业绩效的关系，并试图分析民营企业高管政治联系与地区间政府竞争的关系。 本文采用2003——2008年...Since the reform and opening up, China's private firms have obtained enormous achievements in development, private economy has become an important part of the national economy, In-depth study of the factor of Chinese private firms’ performance is not only theoretically significant, but also practically important. We analysis how political connections have the influence on private firm performance ...学位：经济学硕士院系专业：经济学院经济研究所_区域经济学学号：2902008115223

Modification of Polysilazanes and their Application in the Preparation of SiCN-based Ceramic Composites

聚合物先驱体陶瓷（PDC）法采用化学方法合成聚合物先驱体，然后成型、热解制备陶瓷，开辟了有机高分子制备无机陶瓷的新途径。PDC法的优势在于可通过先驱体的分子设计从而控制陶瓷的组成和微结构，从而调控陶瓷的性能。聚硅氮烷是一类重要的陶瓷先驱体，其烧结制备SiCN和Si3N4陶瓷具有良好的物理、化学和机械性能，不仅是优良的耐高温材料，在微电子器件、锂离子电池等方面也有着广阔的应用前景。 本文以促进聚合物先驱体交联，提高陶瓷产率和陶瓷高温稳定性，以及制备磁性功能陶瓷为目的，设计和制备了一系列金属和硼掺杂改性的共聚聚硅氮烷，对其进行交联和陶瓷化研究，并评价最终陶瓷的耐高温性能和磁性能。采用傅立叶红外光...The preparation of polymer derived ceramics (PDCs) involves synthesis of polymeric precursors, followed shaping, and final pyrolysis. The PDC route enabled significant technological breakthrough in ceramic science and technology, with polymers as starting materials. The composition and microstructure of ceramics are directly influenced by the molecular design of the preceramic precursors, thus the...学位：理学硕士院系专业：材料学院材料科学与工程系_高分子化学与物理学号：2072009115007

两种DOPO阻燃环氧树脂固化剂的室温合成及性能

无卤反应型多元素协同是环氧树脂阻燃研究的热点,室温合成了上述功能的活性DOPO衍生物DOPO-M和DOPOT。它们作为固化剂,分别与4,4’-二氨基二苯甲烷混合,再与等当量环氧树脂E51固化得到阻燃元素含量可控的环氧体系。使用NMR证明了DOPO衍生物结构,使用红外跟踪其固化过程,继而使用DMTA、TGA和LOI测试分别研究了DOPO衍生物引入量、结构区别对环氧树脂热力学性能、耐热性能及阻燃性能的控制趋势。结果表明:(1)阻燃环氧体系都为均相体系;(2)阻燃环氧体系的耐热性能及阻燃性能均得到显著提升;(3)DOPO-M比DOPO-T在提升阻燃环氧体系的耐热性能及阻燃性能上更有优势。湖北省自然科学基金(ZRMS2016001126);;湖北科技学院核技术专项(2018-19KZ06);湖北科技学院校级项目(2016-XC-010,2017-XB-017);;湖北省教育厅优秀中青年人才科研项目(Q20162806)资

Carrying out the Scientific Outlook on Development,Realizing the Revolutionary Transformation of the Development Manner of Township Enterprise

转变经济发展方式是落实科学发展观的本质要求,本文分析了我国乡镇企业的发展现状及存在问题,并按科学发展观的要求,提出了实现乡镇企业发展方式革命性转变的若干举措。Transforming economic decelopment manner is the essential requirments of the scientific outlookon development.this paper analyzedthe current conditions of the development of the township enterprise and the problems arising from the development of the township enterprisein China,then put for ward some measures to transform the development manner of the township enterprise revolutionarily

Construction of polybutycyanocrylate nanoparticles(PBCA-NPs) loaded P16a gene and expression in Hep-2 cell

目的制备携带P16A基因的聚氰基丙烯酸正丁酯纳米粒并在喉癌细胞中进行表达。方法选用乳化聚合法制备PbCA-nPS,以激光粒度分析仪及透射电子显微镜分析纳米粒的形态和粒径。用阳离子表面活性剂十六烷基三乙基溴化铵(CTAb)对纳米粒进行表面修饰。构建真核表达载体PIrES2-EgfP-P16A经过酶切鉴定及测序后与PbCA-nPS连接,转染喉癌细胞HEP-2,荧光显微镜检测转染效率,蛋白印迹法检验P16A基因的表达,流式细胞术检测细胞凋亡率。结果所制PbCA-nPS粒径均匀、zETA电位较高,较为理想;重组质粒PIrES2-EgfP-P16A经过酶切鉴定及测序后,表明真核表达载体构建正确;PbCA-nPS可以介导PIrES2-EgfP-P16A高效转染喉癌细胞,蛋白印迹检测表明转染后喉癌细胞能够表达外源P16A基因,在其介导下P16A能有效抑制喉癌细胞的增殖并能诱导细胞凋亡。结论聚氰基丙烯酸正丁酯纳米粒可以作为一种良好的基因载体,为喉癌的基因治疗提供了新思路。[Objective] To prepare polybutycyanocrylate nanoparticles(PBCA-NPs)loaded P16a gene as the gene delivery system,and to express the P16a protein in Hep-2 cell line.[Methods] PBCA-NPs were prepared by the emulsion polymerization method.Surface of PBCA-NPs was surveyed by transmission electron micrographs(TEM),the grain distribution and zeta potentials of PBCA-NPs were determined with the laser grain analyzer.The PBCA-NPs surface was modified by the cationic surfactant cetyltrimethylammonium bromide(CTAB).Construct the eukaryotic expression vector pIRES2-EGFP-P16a and the recombined plasmid were extracted and purified.After verification by double enzyme digestion and sequencing,the constructed eukaryotic expression plasmid was transfected to Hep-2 line.Transfect ion efficiency was observed by fluorescence microscope and the expression of P16a gene was detected by Western blot.Apoptosis was detected by flow cytomery.[Results] Nps with even size and smooth surface were successfully obtained,holding the higher zeta electric potential.The new constructed vector was confirmed by restricted enzyme and sequencing.pIRES2-EGFP-P16 can be mediated by PBCA-NPs with high transfection efficiency.Exogenous P16a gene can be expressed in transfected Hep-2 cell line detected by Western blot.P16a mediated by Nps can effectively inhibit the proliferation of Hep-2 cell,and induce Hep-2 cell apoptosis in vitro.[Conclusions] PBCA-NPs could be a good vector and provided a new way for gene therapy of laryngocarcinoma.厦门市卫生局科研立项专项资金(序号wsk09)资

FABRICATION OF HYDROXYAPATITE/ALUMINUM OXIDE COMPOSITE COATINGS BY THE COMBINATION OF ELECTROPHORETIC DEPOSITION AND REACTION BONDING PROCESS

在金属表面用电泳沉积(electrophoretic deposition,EPD)法制备羟基磷灰石(hydroxyapatite,HA)涂层的主要问题是结合强度较低。为了提高HA涂层与基体的结合强度,先采用EPD在钛表面制得羟基磷灰石/铝(hydroxyapatite/aluminum,HA/Al)复合涂层,然后采用反应结合方法(reaction bonding process)制备羟基磷灰石/氧化铝(hydroxyapatite/aluminum oxide,HA/Al2O3)复合涂层,并与相同条件下制备的HA单一涂层进行比较研究。用扫描电镜表征涂层的表面和横截面形貌。用能量散射X射线衍射(X-ray diffraction,XRD)谱分析HA/Al2O3复合涂层的化学组成。用XRD仪研究涂层的物相组成和热稳定性。通过黏结–拉伸实验测定HA涂层与基体的结合强度。结果表明:通过850℃热处理,HA/Al复合涂层中的Al粉发生氧化反应生成Al2O3,经反应结合得到HA/Al2O3复合涂层;反应结合提高了HA涂层的致密化程度且降低了基底钛表面的氧化程度;与单一HA涂层相比,HA/Al2O3复合涂层与基底间的结合强度得到明显提高。The major problem in fabricating hydroxyapatite (HA) coating on metal substrate by electrophoretic deposition is the low bonding strength between the coating and substrate. In order to improve the bonding strength,hydroxyapatite/aluminum oxide (HA/Al2O3) composite coating was fabricated on titanium substrate using the combination of electrophoretic deposition and reaction bonding process. The HA single coating was prepared in the same conditions for comparison. Scanning electronic microscope was employed to characterize the surface and cross-sectional morphologies of the as-prepared coatings. The chemical compositions of the composite coating were analyzed through energy dispersive X-ray spectroscopy. X-ray diffraction was used to study the phase com-position and thermal stability of the as-prepared coatings. The bonding strength between the coating and substrate was tested by a shear strength testing experiment. The results show that the Al in HA/Al green coating prepared by the EPD was oxidized to Al2O3,and HA/Al2O3 composite coating was obtained using the reaction bonding process by heat treatment at 850 ℃. The reaction bonding process promotes the coating's sintering densification and improves the substrate's oxidation resistance during the heat treatment. In comparison with the HA single coating,the HA/Al2O3 composite coating exhibits much higher bonding strength.国家自然科学基金(20573086);; 国家科技支撑计划(2007BAE05B04);; 厦门市科技计划(3502Z20063005)资助项

EFFECTS OF SUSPENSION POWDER CONTENT ON THE ELECTROPHORETIC DEPOSITION OF HYDROXYAPATITE COATINGS

从不同羟基磷灰石(hydroxyapatite,HA)粉体含量的悬浮液中,在钛表面电泳沉积HA涂层。采用扫描电镜、X射线衍射表征涂层的微观形貌及物相组成,通过黏结-拉伸实验测定涂层与基底的结合强度。结果表明:提高悬浮液的HA粉体含量,有助于提高电泳沉积HA涂层的致密性,改善其烧结性能,提高烧结致密化程度;HA涂层致密性的提高,有效地抑制了钛基底表面氧化反应,改善了涂层与基底的界面结合状态,使HA涂层与钛基底的结合强度从悬浮液HA粉体含量为5 g/L时的4.54 MPa,提高到悬浮液HA粉体含量为20 g/L时的19.92 MPa。Hydroxyapatite(HA) coatings were deposited on titanium substrate by electrophoretic deposition in suspensions with dif-ferent HA powder contents.The surface and cross-sectional morphologies and phase composition of the as-prepared coatings were characterized by scanning electronic microscopy and X-ray diffraction.The bonding strength between the coating and substrate was tested by a shear strength testing experiment.The results show that suspension HA powder content has a significant effect on the mi-crostructure of the deposited coating,and further on its sintering property and the bonding strength between the coating and substrate.The increase in suspension HA powder content is beneficial in producing dense green coating,improving the sintering process of coating and the oxidation resistance of the substrate,and consequently increasing the bonding strength.The bonding strength between the HA coating and titanium substrate can be increased from 4.54 MPa with a suspension HA powder content of 5 g/L to 19.92 MPa with a suspension HA powder content of 20 g/L.国家自然科学基金(20573086);; 国家科技支撑计划(2007BAE051304);; 厦门市科技计划(3502Z20063005)资助项

Raise of the Frequency in Green-shoot-formation for Rice Anther Cultivation

福建省水稻攻关课题基金 (K790 81);; 厦门市科委科技发展项目 ( 3 5 0 2 2 2 0 0 0 10 4

Studied the difference of genetic feature between tissue cultured and cultivated paddy rice of Jia He Zao Zan via microsatellite(SSR) markers

株高是水稻重要的农艺形状之一,植株过高将导致倒伏和减产,目前,很多新的技术究被用来鉴定,图位克隆与水稻株高相关的基因及机理的研究,本实验选择优质早籼稻佳禾早占种植苗和经过组培获得的矮化突变水稻为材料,为研究比较它们间的遗传物质上差异,根据康耐尔大学的资料设计了311对SSR引物对佳禾早占种植材料和组培材料进行分析,对两种材料进行PCR多态性扩增,结果发现两者间存在多态性的引物有88对,多态性比例达到30.3%。在矮杆材料中不但验证了已报道的11个与调控株高性状基因相连锁的标记连锁群,同时在第3号染色体和第9号染色体上还获得了两个以前基本未有报道的标记集中分布区域。结果说明,该培养基培育出的佳禾早占水稻后代所表现出的矮杆性状与亲本在遗传物质上确有明显差别。该结果有助于挖掘和定位新的矮杆基因,并有利于今后在水稻育种中进行水稻株高性状的控制,同时也为开展矮化性状机理的研究提供有利的实验材料。Plant height is one of the important agronomic traits of rice.Overhigh plant easily led to lodge and reduce output.Recently,great advances have been made in the identification,mapping,cloning and action mechanism of plant height genes in rice.This present paper selected the tissue cultured and cultivated paddy rice of Jia He Zao Zan(J.H.Z.Z) as experimental object,which were significant different on the height,the tissue cultured plant was only less than half height of the cultivated plant.In order to compare their differences of genetic and determine whether there are relationship between the dwarf gene and the dwarf character of tissue cultured plant,Polymorphism analysis was conducted between them by 311 pairs of rice SSR primers,designed by Cornell University,the result indicated that 88 pairs of primers had polymorphism between two kinds of materials,the ration in total primers was about 30.3%,the experimental result not only verified 11 multiple groups which regulate the height gene,but also obtained two group regions which control the dwarf character on chromosome 3 and chromosome 9,which have not been reported previously,these results will help to explore and determine the situation of new dwarf gene,and will be of benefit to act genetic manipulation of plant height of in rice breeding.These results also provided the evidence for studying the mechanism of dwarf.国家863项目(2002AA211091),(20001AA11091);; 厦门大学细胞生物学和肿瘤细胞工程教育部重点实验室开放基金资助(NO:2005108)资

A New Approach to the Surface Reconstruction of Corneal Based on Slit-lamp Imaging

角膜是人眼的重要组成部分,眼外科中对角膜表面检查一般采用基于Placido盘的角膜地形图法和裂隙扫描角膜地形图法,但这两种方法的结果都未能获得直观的角膜表面三维模型。本研究设计的一种基于裂隙扫描图像的角膜表面三维重建算法,实现了对角膜前后表面的重建,并能快速地计算出角膜前后表面的几何参数以及转换成传统的等高线图和地形图,方便了医生的诊断。该算法首先采集角膜的裂隙扫描图像序列,然后在图像集中提取出每层角膜的轮廓,进而采用轮廓线重构算法得到角膜表面模型。在对裂隙图像提取闭合轮廓线时,根据角膜区域的颜色差异,采用了色彩分割的算法;针对角膜轮廓线是凹的特点,对轮廓线重构算法做了改进,以便能构造出正确的角膜表面三角形网格。Cornea is an important part of eyeball. There are two clinical methods that are commonly used in measuring corneal shape. One is Placido-based corneal topography,and the other is Orbscan corneal topography. By using both technologies, 3D corneal surface model can not be obtained. In this paper,a new approach to the surface reconstruction of corneal based on slit-lamp imaging was proposed,which realize visualization for 3D structure of corneal anterior and posterior surface and gain the geometric parameters of its shape fast. At the meantime the results can be transferred the hypsographic map and the topography map to diagnose easily. The algorithm firstly acquires an image series using slit-lamp,secondly extracts the contour of the corneal,at last the corneal surface model is produced using algorithm of contour reconstruction. In abstracting the contour,we adopt color segmentation method according to the difference of the corneal zone. Against the concave characteristics of corneal contour,we improve the algorithm of contour reconstruction to increase the robust of algorithm and obtain the triangle mesh of corneal surface.国家自然科学基金 (60 3 710 12 ) ;; 福建省科技重点项目 (2 0 0 2Y0 2 1);; 面向 2 1世纪教育振兴行动计划项目的支持