2011年第6期第32喜 N 于“b”值的研究多是经过逆城市化和郊区城市化发5]何秀丽.多元战性回归模型与岭回归（项士论文）D,式汉： 展过程之后，而国内城市发展阶段与国外不同，且国 华中科技大学，2005 内各个区域又有很大差异，所以“b”在中国的意义需 6]吕晨，类杰，孙成.基于ESDA的中国人口空间格局及形响 要进一步探讨。米 因素研究0经济地理，2009,29(11)，1797-1802. [门苏飞，张平宇辽中南城市群人口分布的时空演变特征门 参考文献： 地理科学进展，2010,29(1)，096-102. [叮间庆武，卞正富人口空问分布的异质性测量地理研究， [⑧]刘盛和，邓羽，胡章.中国流动人口地城类型的划分方法及 2009,28(4):893-900. 空间分布特征[0，地理学报，2010,65(10)，1187-1197. [2☑彭际作.大都市图人口空间格局及区城经济发展一以长 9]刘凝彬江西省城市化与生态环境关系的动态计量分折们， 江三角洲大都市图为例[D],上海：华东师范大学，2006. 黄潭科学，2008,30(6)，829-836. [3]Heikkila E,Gordon P,Kim J et al.What had to the CBD- [10]新春玲，重力.基于PSR模型的城市水安全评价研究们， distance gradient?Land values in a polycentric city [Envi- 安全与环境学报，2009,9(5)，104-108. ronment and Planning A,1989,21(2):221-232. [11】陈思.兰一西城镇区战PREE系统的互动反情机制研究 [4孙铁山，李国平等.京津冀都市图人口集聚与扩散及其衫响（项士论文）D.西安：西北大学，2010 因素一基于区战密度函数的实证研究仞，地理学报，[2]陶晓燕，基于改进广义浦值法的城市竞争力研究门科技 2009,64(8):956-966. 进步与对策，2009,26(14)：131-133. Analysis on the Shift of the Population Density Gradients in Lanzhou-Xining City Region and Its Mechanism HUANG Yong-bin,BAI Yong-ping (School of Geography and Enwironment,Northwest Normal University,Lanzhou 730070,Gansu,China) Abstract:In this paper the polycentric regional density function which is based on the square-root negative exponential function is used to analyze the population density gradient in Lanzhou-Xining city region,and thus to evaluate the trend of the concen- tration and decentralization of the population.Then,the multiple linear regression model is build to evaluate which are the rea- sons to cause the changes of the population density gradient among several factors we define.Estimations results of the polycen- tric regional density function display that the top three high population density centre cities,which is Lanzhou,Xining and Linxia,show different change trend of population density gradient and different pattems of concentration and decentralization of population.The gradient grows higher and higher in Lanzhou and Xining,and thus implies the concentration trend of population in the center.While,it grows lower and lower in Linxia city,and the decentralization pattem of population can be induced.Since the multicollinearity occur among index we define,so the ridge regression method is used to build the multiple linear regression model And the estimation result shows that the urban scale,the proportion of those who works in the second industries and the the transportation accessibility is highly relative to the density gradient coefficient.However,the proportion of thoee whowok in the first industries and the third industries,and the ecological environment quality score is tested insignificant. Key words:population density gradient;polycentric regional density function;ridge regression;Lanzhou-Xining city region (上接35页) The Adaptability of Migrant Workers and the Formation of Semi-urbanization in China LI Gang (School of Economics,Anhui University of Finance Economics,BengBu,AnHui 233030) Abstract:At present,China is facing semi-urban issues that can not be ignored.Semi-urbanization is inevitable phenomenon in typical of China by "urban-rural dual structure"to"urban and rural integration of purely"transitional stage in the process of change.According to "disembedding-embedding"theory,we can see that reform and opening up of China from planned economy to market economy,greatly accelerated the pace of economic development.China's current economic activities be- tween urban and rural has been fully integrated with the completion of the "disembedding-embedding"process.However, the management system in urban and rural,urban and rural culture,habits,social identity,social peychology are not yet complete "disembedding-embedding"process,leading to the emergence of semi-urbanization.Govemments should take measures to reduce the time that is form the“semi-urban'”to“pure uban-rural integration”. Key words:Adaptability of migrant workers;Semi-urbanization;Disembedding-embedding ·40. VdL32No.6(142)2011 万方数据2011年第6期第32卷 洲以筋勰 于“b”值的研究多是经过逆城市化和郊区城市化发 展过程之后，而国内城市发展阶段与国外不同，且国 内各个区域又有很大差异．所以“b”在中国的意义需 要进一步探讨。始 参考文献： 【1】国庆武，卞正富．人口空间分布的异质性测量叨．地理研究， 2009．28(4)：893—900． 【21彭际作．大都市圈人口空间格局及区域经济发展——以长 江三角洲大都市圈为7J[D]。上海：华东师范大学．2006． 【3]Heikkila E，Gordon P，Kim J et a1．矾砒had to the CBD— distance gradient?Land values in a polycentric city叨．Envi— ronment and Planning A。1989，21(2)：221-232． [41孙铁山．李国平等．京津冀都市圈人口集聚与扩散及其影响 因素——基于区域密度函数的实证研究叨．地理学报， 2009，“(8)：956-966． 【5】何秀丽．多元线性回归模型与岭回归(硕士论文)【D】．武汉： 华中科技大学．2005． 【6】吕晨，樊杰，孙威．基于ESDA的中国人口空间格局及影响 因素研究叨．经济地理，2009，29(11)，1797—1802． 【7】苏飞，张平宇．辽中南城市群人口分布的时空演变特征叨． 地理科学进展，2010，29(1)。096-102． [8】刘盛争，邓羽，胡章．中国流动人口地域类型的划分方法厦 空间分布特征阴，地理学报，2010，65(10)，1187—1197． 【9】刘耀彬．江西省城市化与生态环境关系的动态计量分析叨， 资源科学，2008，30(6)，829—836． [10]-靳春玲，贡力．基于PSR模型的城市水安全评价研究叨， 安全与环境学报，2009，9(5)，104-108． [11】陈思．兰一西城镇区域P眦系统的互动反馈机制研究 (硕士论文)田】．西安：西北大学，2010． 【12】陶晓燕．基于改进广义熵值法的城市竞争力研究口丁．科技 进步与对策，2009，26(14)：131—133． Analysis on the Shift of the Population Density Gradients in Lanzhou-Xining City Region and Its Mechanism HUANG Yong-bin，BAI Yong-ping 俾枷Z ofGeogrqp砂and Environment，Northwest Normal Univers蚵，Lanzhou 730070，Gansu，China) Abstract：In this paper the polyeentrie regional density function which is based on the square-root negative exponential function is used to analyze the population density gradient in I．znzhou-Xining city region，and thus to evaluate the trend of the concen￾tration and decentralization of the population．Then，the multiple linear regression model is build to evaluate which a弛the∞ea． 80118 to calL．鸵the changes of the population density gradient among several factors we define．Estimations results of the po|ycen￾tric regional density function display that the top three lligh population density centre cities，which is Lanzhou，Xinlng and Linxia，show different change trend of population density gradient and different pottems of concentration and decentralization of population．The gradient grows hisber and higher in Lanzhou and Xining，and thus implies the concentration trend of population in the center．While，it grows lower and lower in Linxia city，and the decentralization pattern of population can be induced．Since the multicollinearity occurs among index we define，80 the ridge regression method is used to build the multiple linear regression model．And the estimation result shows that the urban scale，the proportion of those who works in the second industries and the the transportation accessibility is highly relative to the density gradient coefficient．However，the proportion of those who wodaI in the first industries and the third industries。and the ecological environment quality gcore is tested insignificant． Key words：population density gradient；polycentric regional density function；ridge regression；Lanzhou-Xining city region (上接35页) The Adaptability of Migrant Workers and the Formation of Semi-urbanization in China LIGang (School ofEconomics，Anhui Univers妇ofFinance＆Economies，BengBu，A rdtui 233030) Abstract：At present，China is facing semi—urban issues that Call not be ignored．Semi-urbanization is inevitable phenomenon in typical of China by“urban—rural dual structure”to“urban and rural integration of purely’’transitional stage in the process of change．According to“disembedding—embedding”theory，we can see that reform and opening up of China from planned economy to market economy。greatly accelerated the pace of economic development．China’8 current economic activities be￾twcen urban and rural has been fully integrated with the completion of the “disemlxdding—embedding”process．However。 the management system in urban and rural，urban and rural culture，habits，social identity，social psychology are not yet complete“disembedding—embedding”process。leading to the emergence of semi-urbanization．Governmen协should take measures to姒luce the time that is form the“semi-urban”to“pure urban-mrs]integration”． Key words：Adaptability of migrant workers；Semi-urbanization；Diseml)edding-embedding ‘ ·40· VoL32 No．6(142)2011 万方数据