耦合生态系统服务供求关系的生态安全格局动态分析——以闽三角城市群为例

实现分区管理是缓解城市群生态安全空间差异的有利途径。基于供求理论构建了生态系统服务供求关系动态模型框架,并利用供给与需求的象限区划表征闽三角城市群生态安全格局;在不同的尺度变换上,运用价值单量修正模型、INVEST生境质量模型、景观指数模型、生态韧性模型、熵权法等方法综合测度城市群生态系统服务供求水平,实现生态安全格局的分区化;引入环境库兹涅茨曲线理论解析区域生态安全格局现状和成因;数据分析借助Arc GIS可视化表示。研究发现:(1)闽三角城市群存在50%区域属于生态安全高供给失衡区,其中70%属漳州市境内;32.14%属于高需求失衡区,集中于市辖区与沿海地区;17.86%属于双维度失衡区;未存在单元位于双维度共赢区上。(2)区域生态系统服务供给颇佳而需求滞后,城市群东南沿海区域与周边区域格局差异明显,供给(需求)呈现由沿海向内陆梯次增(减)的空间分异规律。(3)城市群尚处于生态安全库兹涅茨曲线的\"两难阶段\",同时导致了城市群生态安全格局空间异质性的产生。国家重点研发计划(2016YFC0502901);;国家自然科学基金项目(41771500

农民工返乡创业的融资行为及影响因素分析——基于福建省龙岩市的调查

融资难一直是困扰返乡农民工创业的最主要问题。本文基于福建省龙岩市的调研数据,从融资渠道、融资可获得性、融资成本、融资效率等4个方面分析农民工返乡创业融资的行为特征,进而从创业者年龄、创业者最高文化程度、创业年限、经营规模、行业类型、地区分布、社会资本情况等7个方面对融资行为的影响因素进行深入剖析。结果表明,创业者年龄与融资成功率呈现明显的反向关系;创业者最高文化程度与从正规金融渠道融资成功率呈显著的正向关系;随着创业年限和经营规模的增加,返乡农民工从正规金融渠道融资成功率逐步提高,而从非正规金融渠道融资成功率却趋于下降;返乡农民工创业融资行为存在明显的行业和地区差异性;社会资本对返乡农民工创业融资行为具有正向促进作用。笔者牵头领导的厦门大学2012年大学生暑期实践项目“龙岩市返乡农民工创业融资问题研究”; 中共福建省委组织部“地方科技副职产学研合作基金”的资

基于B/S架构的复杂抽样调查统计推断系统

基于B/S构架的复杂抽样调查统计推断系统采用跨平台设计,与业务系统及数据库无缝链接。系统提供随机抽样、分层抽样、Neyman分层抽样、不等概率抽样(PPS)、多阶段抽样等常用抽样算法。系统用户根据研究目标自定义组合抽样方法,系统根据样本和总体属性及用户抽样方案自动推算统计推断结果及置信区间,实现抽样调查、统计推断的自动化与系统化

金融竞争力、辐射力与海峡两岸区域性金融中心构建

文章运用熵值法和灰色关联分析法计算福建各城市金融竞争力指数,进而采用威尔逊模型和断裂点理论分析中心城市金融辐射的有效半径。研究结果表明,厦门的综合金融竞争力高于福州,两地在分项指标上则各有所长;厦门在对漳州和泉州的辐射影响力占据优势,福州在对莆田和宁德的辐射影响力居于主导地位。因此,基于建设两岸区域性金融中心的本质要求,应逐步构建以厦门、福州为主体,泉州为延伸,错位发展、优势互补的海西区域金融一体化体系

Research advances of electrochemical micro/nanofabrication based on confined etchant layer technique

与机械加工相比, 电化学加工技术具有无刀具磨损、无热效应、无机械损伤、加工效率高等优点, 而且适用于柔性、脆性及超硬材料,; 具备传统方法难以实现的复杂结构加工能力, 因而在航空航天、汽车、微电子等领域有着重要应用, 日益成为一种重要的工业制造技术.; 随着超大规模集成电路(ULSI)、微机电系统(MEMS)、微全分析系统(mu-TAS)、现代精密光学系统等高技术产业的迅速发展,; 功能性结构/器件的微型化和集成化的要求越来越高. 由于传统电化学只适用于金属材料, 为了应对微纳制造的时代要求, 拓展电化学加工的材料普适性,; 1992年田昭武院士提出了具有我国自主知识产权的约束刻蚀剂层技术(CELT). 一般的, 约束刻蚀包括3个步骤:; (1)通过电化学、光化学或光电化学的方法在模板电极表面生成刻蚀剂;; (2)通过后续的均相化学反应或自由基衰变反应将刻蚀剂约束在微/纳米厚度的液层内; (3)将模板电极逼近加工基底,; 当约束刻蚀剂层接触被加工基底时, 通过刻蚀反应实现微纳加工. 最近, 联合课题组通过仪器、原理和方法3个方面的努力, 引入外部物理场调制技术,; 实现一维铣削、二维抛光、三维微/纳结构加工, 大幅提升了CELT的技术水平.Compared with mechanical machining, ECM has several advantages, such as; avoiding tool wear, none thermal or mechanical stress on machining; surfaces, as well as high removal rate. Moreover, ECM is capable of; making complex three-dimensional structures and is appropriate for; flexible, fragile, or fissile materials even materials harder than the; machining tool. Thus, ECM has been widely used for various industrial; applications in the fields of aerospace, automobiles, electronics, etc.; ECM methods can be classified usually as electrolytic machining based on; anodic dissolution and electroforming based on cathodic deposition of; metallic materials. Recently, high technology industry, such as; ultralarge scale integration (ULSI) circuits, microelectromechanical; systems (MEMS), miniaturized total analysis systems (mu-TAS) and; precision optics, has developed more and more rapidly, where; miniaturization and integration of functional components are becoming; significant. Nowadays, the feature size of interconnectors in ULSI; circuits has been down to 20 nanometers, predicted by Moore's law.; Confined etchant layer technique (CELT) was proposed in 1992 to; fabricate three-dimensional micro- and nanostructures (3D-MNS) on; different metals and semiconductors, which has been developed an; effective machining method with independent intellectual property; rights. Generally, there are three procedures in CELT: (1) generating; the etchant on the surface of the tool electrode by electrochemical or; photoelectrochemical reactions; (2) confining the etchant in a depleted; layer with a thickness of micro- or nanometer scale; (3) etching process; when the tool electrode is fed to the workpiece, which applicable for 1D; milling, 2D polishing, and 3D microfabrication with an accuracy at micro; or nanometer scale. External physical-field modulations have recently; been introduced into CELT to improve its machining precision. In this; review, the advances of CELT in principles, instruments and applications; will be addressed as well as the prospects.国家自然科学基金; 机械制造系统工程国家重点实验室开放课题资助项

Study on Water Environmental Capacity of Reservoired River in Jiulong River Basin

针对九龙江流域湖库化问题,确定湖库化河段判定标准,提出综合电站的概念,基于大量的实测数据进行水质模型的降解系数值k参数率定,以此为基础,提出湖库化河段水环境容量计算方法,对九龙江流域湖库化后的水环境容量核算开展研究,确定了流域河流湖库化对水环境容量计算的影响,湖库化河段的水环境容量,为流域的水环境容量总量控制和管理、决策提供科学的依据.According to the problem of reservoired in Jiulong River basin,the judgment standard of reservoired river was determined,and the concept of integrate hydropower station was presented.Then,the parameter value of degradation coefficient K was calibrated with water quality model based on a large number of measured data of water quality.On this basis,calculation method of water environmental capacity for reservoired river was proposed.Finally,research was carried on water environmental capacity accounting of reservoired river in Jiulong River basin.The results show the effect of reservoired on water environmental capacity calculation,and the water environmental capacity of reservoired river,which provided scientific basis for the total emission control,management and decision-making of water environmental capacity in Jiulong River basin.福建省环保资助项目(ZLT0903); 福建省科技重大专项(2013YZ001-1