The study of the role of governments in industrial clusters

随着世界经济的发展，科技的进步，信息技术和交通工具越来越发达，但是地理位置在经济竞争中的地位并没有削弱—--世界上出现了许多创造经济奇迹的产业集聚区，我们称这些产业集聚区为产业集群。由于产业集群对区域经济贡献巨大，引起了学术界和区域政府的重视，已经成为近年来经济学研究的热点话题和政府制定经济政策、产业政策的重点考虑内容。产业集群的概念如何界定，至今还没有一个统一的被大家接受的结论，产业集群的辨认分类也各地各有千秋，产业集群对区域经济贡献巨大，受到人们的追捧，是因为其有其他经济发展模式没有的竞争优势，但是竞争优势表现在那些方面，源自那些方面，波特的钻石模型对产业集群竞争优势研究有哪些帮助，我们在...With the development of world economy, technology improvement, telecommunication and transportation methods become more and more developed, but the role of geography factors in economic development is not decreasing—there became many marvelous industrial concentration regions, we call them “industrial clusters”. Since then Industrial clusters devoted a lot to regional economic development, also ap...学位：经济学硕士院系专业：经济学院财政系_财政学(含税收学)学号：2005130079

Load Spectrum Compiling Based on Operation Section Recognition and Fatigue Life Prediction of Wheel Loader Axle Shaft

为改进轮式装载机可靠性及耐久性设计中数据清洗和分析的方法,以装载机半轴为对象,优化载荷信号去噪和作业段识别的方法。利用小波自适应阈值法去除实测载荷的噪声尖峰和突变信号,并通过迭代平滑滤波法搜寻单个作业周期内同步载荷信号的极值点,识别、划分作业段为＂行走段-铲掘段＂。结合雨流计数和频次外推法编制载荷谱,有限元静力分析,以及Miner准则对装载机半轴进行疲劳寿命分析。结果表明：雨流计数的均幅值结果符合正态分布和三参数威布尔分布的假设性检验,疲劳分析损伤最大节点出现在万向节叉连接处,其寿命为7.22×10^8次循环。结果证实了作业段智能识别法的便利性和准确性,为传动系统疲劳分析的数据处理提供了借鉴。In order to improve the method of data cleaning and data analysis in fatigue durability and modify reliability design of wheel loader,research on load signal denoising and operation section recognition of wheel loader axle shaft was conducted. In view of the shortcoming of residual noise and waveform distortion caused by traditional wavelet threshold analysis,an adaptive threshold denoising method was used. Operation sections were divided as＂driving section-shoveling section＂through searching the extreme points of synchronous load signal in one single work cycle after iterative smoothing filter. Based on one-dimensional program loading spectrum and the finite element analysis,the fatigue life of axle shaft was predicted using the Miner criterion. The result shows that rain flow counting results were consistent with Normal distribution and Weibull distribution hypothesis testing. And the maximum damage node appeared in the universal joint folk which fatigue life is 7. 22 × 10^8 times cycle. The result confirmed that the intelligent recognition method is convenient and accurate,which provides a reference method for data processing of fatigue analysis of wheel loader transmission system.福建省财政厅企业技术创新项目资

Expert system for Web-based FEA pre-processor

为实现大批量定制产品远程分析过程的智能化和知识重用,提出了一种基于知识工程的网络化前处理专家系统。通过对有限元建模和分析过程的标准化、参数化、模板化和知识化的研究,着重论述了专家系统的结构、功能特点和实现策略,其中前处理过程中涉及的专家经验、理论知识和典型分析实例等知识,被分类为分析过程知识和产品结构对象知识,并采用基于逻辑规则和面向对象的知识模型予以表达,从而构建了支撑专家系统的知识库,并给出了基于实例的推理和基于规则的推理相结合的混合推理机制。最后,给出了某数控机床立柱结构的远程分析过程实例,以说明该有限元分析专家系统的有效性。To realize the intelligent-oriented analysis process and knowledge reuse for Mass Customization(MC) product,an expert system for Web-based Finite Element Analysis(FEA) pre-processor was developed based on knowledge engineering.According to the research on the standardization,template and knowledgeable of Computer Aided Engineering(CAE) modeling and analysis process,the system structure,function and implementation methods were studied in particular.In this system,the experts' experiences,theories and typical examples and other related knowledge,which could be used in the stage of pre-process in FEA,were categorized as analysis process and object knowledge.Then,the integrated knowledge model based on object-oriented method and rule-based method was constructed.The integrated reasoning process based on case-based reasoning and rule-based reasoning was presented.Finally,an example of remote structure analysis of a typical machine tool′s column was given to illustrate the effectiveness of the expert system.国家自然科学基金资助项目(70402013,70772093);; 福建省高等学校新世纪优秀人才支持计划资助项目~

Research on composite structure optimization method of large parts of machine tool

在分析机床广义模块设计和结构智能优化的基础上,论述基于人工神经网络和有限元优化的大件模块结构复合优化方法,给出大件模块结构的尺寸优化设计变量自动搜索寻优计算方法及整机部件间的协调优化方法,实现部件间关键尺寸的快速协调优化,提高产品的性能和设计效率。最后,给出某数控机床的大件结构复合优化案例,说明该方法的有效性。On the basis of analysis of machine tool in the general modularization and structural intelligent optimization,the composite structure optimization method of component module based on FEA and artificial neural networks was discussed,and the automatic searching of the optimal solution of the design variables for component module and coordination optimization among component module were given,so that the rapid coordination and optimization of key dimensions between components are realized,and the product performance and design efficiency were improved.Finally,gave a case of composite optimization of large parts for a type of NC machine to illustrate the effectiveness of this method.厦门大学新世纪优秀人才支持计

Rapid variant design of machine tool based on parametric techniques

在产品的概念设计过程中,融入参数化技术,实现大规模定制化产品的快速设计。针对机床产品,以UG为软件平台,结合VC++和SQLServer数据库开发机床产品参数化变型系统,并讨论从功能需求到结构参数模型的映射过程、主要结构特征尺寸参数化等关键技术,通过参数化实现产品级的机床快速变型设计。The rapid design base on mass customization was realized by the parametric techniques in the conceptual design of product.A machine tool is taken as an example,the parametrized variant system was developed which uses UG as a modeling software platform and VC++,SQL Server as developing tools.And then the main technology of the mapping process from function model to structure model,the parameterization of main structural feature size were discussed.By the parametric techniques,a product-level rapid variant design of machine tool can be implemented.厦门大学新世纪优秀人才支持计

Rhizosphere soil nutrient and enzyme activity of Casuarina equisetifolia clone plantation and seedling plantation

木麻黄无性系林根际土壤有机质、全氮、水解氮、全磷、全钾、速效钾、钙和镁离子含量均大于木麻黄实生林,有效磷含量则相反。与实生林相比,木麻黄无性系林根际和非根际土壤pH值均有所下降,CEC值增加。木麻黄无性系林根际土壤脲酶、磷酸酶、过氧化物酶及多酚氧化酶活性均高于木麻黄实生林。脲酶除外,其余3种酶活性均是根际大于非根际。与木麻黄实生林相比,木麻黄无性系林根际环境得到改善,林地土壤营养贮量和养分供应能力提高,生长效果亦优于本地实生苗造林。The results showed that the contents of organic matter,total N,Hydrolytic N,total P,total K,available K,Ca2+ and Mg2+ in rhizosphere soil of clone plantation were higher than those of seedling plantation,except for available P.Compared to seedling C.equisetifolia,pH value of soil declined in clone plantation but CEC value increased.Uresese,phosphataese,peroxidase and polyphenol oxidase of rhizosphere soil were more active in clone plantation than those in seedling plantation.Environment in rhizosphere soil of C.equisetifolia clone plantation was improved and nutrient-holding and providing capacities were enhanced,therefore,growth status was better than seedling C.equisetifolia.国家“十一五”科技支撑计划项目(2006BAD03A14-01,2006BAD01A16);; 福建省重大专项和福建省林木种苗攻关项

Pollen Tube Behaviour of Interspecies Hybridization between Rice and Sorghum Observation

水稻和高粱是禾本科的两个异属作物,因其遗传距离较远,杂交表现不亲和,结实率极低,难以获得种子。为初步了解水稻与高粱属间远缘杂交花粉管行为,探索该远缘杂交的发生过程,本实验以籼稻珍汕97A×珍汕97B和Ⅱ-32A×Ⅱ-32B两个组合为对照,对珍汕97A×晋江多枝高粱和Ⅱ-32A×晋江多枝高粱两个属间远缘杂交组合的花粉管行为作初步的观察与研究,结果表明:晋江多枝高粱花粉粒能象水稻花粉粒一样在水稻柱头上正常萌发,花粉管在花柱及子房中生长与伸长,有些能最终到达子房的基部;同时高梁花粉管生长也出现诸如不能进入花柱、胼胝质不规则堆积、花粉管末端钝化等一系列的异常表现,致使不少花粉管停滞生长。Rice and Sorghum belongs to different genus. Distant hybridization bet ween them becomes incompatible because of their further genetic distance. In ord er to detect the process of distant hybridization and the behavior of pollen tub es in the process, we conducted primary observation and research of the behavior of pollen tubes between two hybridization combinations of Zhenshan97A×Jinjiang duozhi sorghum and Ⅱ-32A×Jinjiangduozhi compared with that of Zhenshan97A×Zhe nshan97B and Ⅱ-32A×Ⅱ-32B. The results showed that the pollen of Jinjiangduozh i sorghum can germinate on the rice stigma normally just as rice's pollen. The p ollen tubes also can grow and elongate on the style and ovary, some can reach th e base of the ovary eventually. Meanwhile, the pollen tubes of sorghum present a series of abnormal phenomenon, such as pollen tubes unable to enter into the st yle, callose depositing irregularly and the bottom of pollen tubes getting passi vated, which brings about many pollen tubes stagnate

水稻辐照花粉受精行为的研究

水稻辐照花粉受精行为的研究王侯聪，陈正明，陈如铭，杨觉民（厦门大学生物系，厦门）杨惠杰（福建省农科院稻麦研究所）用0、0.093、0.186和0.372kgy的￣60COy射线辐照不育系的保持系V＿20b的成熟花穗，辐照后即在不育系V＿20A（经温汤..

高龄孕妇的妊娠结局

【目的】了解高龄孕妇的妊娠结局,为提高该高危人群的围产期预后提供指导。【方法】回顾性分析2006年2月11日至2006年10月7日在我院分娩的156例年龄介于35～48岁高龄孕妇的妊娠结局,并随机选择同期分娩的年龄介于21～34岁的孕妇156例作为对照。【结果】高龄组剖宫产率及辅助生育受孕率均显著高于对照组,妊娠期糖尿病及糖耐量异常、胎儿窘迫、早产的发生率高于对照组,而HSV及CMV感染显著低于对照组,两组新生儿畸形率及围产儿死亡率差异无显著性。【结论】高龄与早产、胎儿窘迫、妊娠期糖尿病、剖宫产率升高等不良妊娠结局密切相关。在妊娠期应加强对高龄孕妇糖尿病和早产等高危因素的筛查,分娩过程中密切监护,及早发现胎儿窘迫的征兆,改善妊娠结局

Rhizosphere Soil Nutrient and Enzyme Activity in Different Stand Age of Casurina equisetifolia Protection Forest

在福建省东山县滨海沙地,开展了不同年龄木麻黄林地根际和非根际土壤养分和酶活性的测定,研究结果表明:(1)不同年龄木麻黄林地根际pH小于非根际土壤,随林龄增长根际土壤和非根际土壤pH值均表现为下降趋势;根际土壤有机质、全氮和水解氮含量高于非根际土壤,各土层有机质含量在中龄林时最大;从中龄林阶段至过熟林,水解氮含量下降;全磷和速效磷含量从幼林发育至中龄林、近熟林逐渐减少,至过熟林略有恢复;根际土壤全钾、速效钾含量呈增加趋势。(2)不同年龄木麻黄林地根际CEC值、水解性总酸度、交换性盐基总量、交换性M g2+均大于非根际土壤;幼林龄根际交换性C a2+低于非根际;土壤CEC值在中龄林时最高。(3)不同年龄木麻黄林地根际土壤磷酸酶、过氧化物酶和多酚氧化酶活性均大于非根际土壤;随着林木的生长,根际和非根际土壤磷酸酶活性逐渐升高,并且根际与非根际间的差异也呈增大趋势;根际过氧化物酶活性从幼龄林到中龄林下降,随着林木生长至过熟林有所升高;根际多酚氧化酶活性在过熟林阶段高于其它发育阶段。This article emphatically reviews the difference of soil chemical properties and biochemical activities between the rhizosphere and non-rhizosphere soil in different stages of Casuarina equisetifolia.It also reviews their dynamic patterns during Casuarina equisetifolia development.The result showed as follows:(1)In different stages of C.equisetifolia protection forest development, the pH value in rhizosphere soil was lower than that in non-rhizosphere soil and it shows the trend of declination in both rhizosphere soil and non-rhizosphere soil;The contents of organic matter,total N and hydrolytic N in rhizosphere soil was more than those in non-rhizosphere soil;Hydrolytic N shows the trend of declination in both rhizosphere soil and non-rhizosphere soil form half-mature stage to mature-stage;the content of total P and available P decreases from young stage to near-mature stage,and rehabilitate a little at mature stage;the content of total K and available K increases in rhizosphere soil.(2)In different stages of C.equisetifolia plantation development,the CEC,hydrolytic acidity and exchange Mg~(2+) in rhizosphere soil were more than those in non-rhizosphere soil,except for exchange Ca~(2+) in young C.equisetifolia protection forest;the CEC of soil arrive its max in half-mature stage.(3)As for the variation of the soil enzyme activity in different stages of C.equisetifolia protection forest,phosphataese,peroxidase and polyphenol oxidase were more active in rhizosphere soil than in non-rhizosphere soil;there was no obvious change on activity of urease;during stages of C.equisetifolia forest development,the active of phosphataese shows the trend of increase in both rhizosphere soil and non-rhizosphere soil,moreover,the difference between rhizosphere soil and non-rhizosphere soil were more obviously;the active of polyphenol oxidase in rhizosphere soil was more than that in other stages.国家“十五”科技攻关项目(2004BA516A13-15);; 国家林业局南方山地用材林培育重点实验室资助项