京津冀地区制造业空间格局演化及其驱动因素   总被引：2，自引：2，他引：0  

蒋海兵  李业锦 《地理科学进展》2021,40(5):721-735

京津冀地区产业转移升级、协同发展和先进制造业深度融合发展战略对制造业产业集群的空间布局提出更高要求。论文基于2000—2013年京津冀地区规模以上工业企业微观数据,运用核密度分析法和面板数据回归模型等方法,探究京津冀地区制造业空间格局演化特征及其驱动因素。结果表明：① 京津冀地区全部制造业总体格局相对稳定,高值区集聚于京津唐地区。资本密集型产业区域联动发展势头明显;技术密集型产业则日趋集中于少数区县,且与周边区县空间自相关程度整体弱化;劳动密集型产业区县邻近扩张与疏散转移发展交替出现。区域联动发展促进各地制造业均衡增长,缩小了区域制造业发展差距。② 京津冀地区制造业呈现出明显专业化地域分工趋势。劳动密集型产业日益向中心城市城区外围及中南部县区集中扩散;资本密集型产业集聚于环渤海西岸产业带,京津冀外围地区产业产值大幅度增加;技术密集型产业扎堆于京津高科技产业带。③ 3类制造业的关键驱动因素有所差异。劳动力密集型产业受投资和交通可达性影响;资本密集型产业对本地市场规模和投资依赖性强,受交通可达性影响弱;技术密集型产业主要受制于交通可达性与工资水平。3类制造业均明显受到地方财政支出作用影响。研究可为城市群先进制造业产业空间优化提供参考依据。  相似文献   

Forecasting prices of single family homes using GIS-defined neighborhoods     

Mak Kaboudan  Avijit Sarkar 《Journal of Geographical Systems》2008,10(1):23-45

We estimate spatiotemporal models of average neighborhood single family home prices to use in predicting individual property prices. Average home-price variations are explained in terms of changes in average neighborhood house attributes, spatial attributes, and temporal economic variables. Models adopting three different definitions of neighborhoods are estimated with quarterly cross-sectional data over the period 2000–2004 from four cities in Southern California. Heteroscedasticity and autocorrelation problems are detected and adjusted for via a sequential routine. Results of these models suggest that forecasts obtained using city neighborhood average price equations may have advantage over forecasts obtained using city aggregated price equations.   相似文献   

自动气象站采集器显示板维修经验     

Xu Yuanyuan  Xie Jun 《河南气象》2007,(Z1)

根据ZQZ-CⅡ型自动气象站采集器的显示板的工作原理及维修实际经验,介绍了维修显示板的基本方法及主要芯片的性能,并对典型故障进行举例分析。  相似文献   

基于Weibull函数和Gamma函数的环境污染与经济增长的关系   总被引：4，自引：1，他引：3  

宋涛  郑挺国  佟连军 《地理研究》2007,26(3):569-576

环境库兹涅茨曲线是研究环境污染与经济增长之间关系的有效工具。传统的环境库兹涅茨曲线研究大多采用线性模型或对数线性模型,其在采用模型描述关系的问题上存在一定的不足。为克服这些不足,本文采用Weibull函数和Gamma函数形式的面板数据模型对中国29个省区1989~2005年四种环境污染指标人均排放量与人均收入之间的关系予以研究。结果表明Weibull函数和Gamma函数的面板数据模型拟合效果较好,且参数具有较好的解释能力;人均废水和人均SO₂都随人均收入增加先上升后减少,在25000元附近出现结构转变点,而人均固体废弃物和人均废气随人均收入增加则呈现单调增加的变化趋势,没有出现结构转变点。  相似文献   

外商直接投资技术溢出空间效应及其变化——基于中国地级市的实证研究   总被引：2，自引：1，他引：1  

季颖颖  郭琪  贺灿飞 《地理科学进展》2014,33(12)

FDI(外商直接投资)对内资企业的技术溢出效应是国内外研究的重要话题,但相关文献多为静态研究.本文认为FDI的技术溢出存在时间效应,即FDI对内资企业的技术溢出或挤出效应,随着FDI进入东道国的时间推移而变化.利用2003-2007年中国工业企业数据库,以通信设备、计算机和其他电子设备制造业为例,对城市面板数据建立门槛回归模型,研究FDI技术溢出效应随时间变化的动态过程.结果表明,随着FDI进入东道国的时间推移,技术溢出效应的变化呈扁S曲线:初始,FDI对内资企业表现为明显的挤出效应;3～4年后,逐渐由挤出效应向溢出效应转变;随着时间的进一步推移,溢出效应减缓下降,最终表现为不明显的溢出或挤出效应.此外,对不同所有制的内资企业,FDI技术溢出效应随时间变化的动态过程不同.  相似文献   

网衣对波浪传播影响的三维数值模拟          下载免费PDF全文

曾启东  董国海  赵云鹏  张晓明  汪睿 《海洋工程》2014,32(6):98-104

为研究网衣对波浪传播的影响,采用多孔介质模型模拟网衣,建立了模拟网衣与波浪相互作用的三维数值波浪水槽模型。基于该数值模型研究了波浪经过网衣作用后波高衰减的变化规律,并与物理模型试验结果进行比较。通过对比数值模拟和物理模型试验的结果,证明了该三维数值模型模拟网衣对波浪传播影响的可行性。  相似文献   

A Study of Resource Curse Effect of Chinese Provinces Based on Human Developing Index   总被引：1，自引：1，他引：0  

HUANG Yue  FANG Yangang  ZHANG Ye  LIU Jisheng 《中国地理科学(英文版)》2014,(6):732-739

Traditional opinion considers that natural resources play an important positive role in economic development, while resource curse theory holds that natural resources usually obstruct economic increase. This debate needs further exploration. In most of empirical studies on resource curse theory, the economic development of an area is mainly evaluated by the Gross Domestic Product （GDP）, however, the social and cultural contents of economic development are seldom considered. Thus, the Human Developing Index （HDI） was chosen to describe the comprehensive developing situation of an area in our study. Based on the panel data from the year of 2000 to 2011, the relationship between Human Developing Index and resource exploitation degree （RED） of 30 provinces in China （Tibet, Tai- wan, Hong Kong and Macao were not included because of the restriction of data acquisition） was investigated by correlation coefficient analysis and regression analysis. We found that resource curse did exist over the entire country and its effect on 30 provinces were not exactly the same. According to the effects of resource curse, these provinces could be classified into four types： no resource curse prov- inces, slight resource curse provinces, severe resource curse provinces, and extreme resource curse provinces. Testing from two short time periods 2000-2005, and 2006-2011, the resource curse effect was not prominent. However, testing from the entire period of 2000-2011, the effect was obvious among each province.  相似文献   

Might electricity consumption cause urbanization instead? Evidence from heterogeneous panel long-run causality tests     

《Global Environmental Change》2014

The share of a population living in urban areas, or urbanization, is both an important demographic, socio-economic phenomenon and a popular explanatory variable in macro-level models of energy and electricity consumption and their resulting carbon emissions. Indeed, there is a substantial, growing subset of the global modeling literature that seeks to link urbanization with energy and electricity consumption, as well as with carbon emissions. This paper aims to inform both modelers and model consumers about the appropriateness of establishing such a link by examining the nature of long-run causality between electricity consumption and urbanization using heterogeneous panel methods and data from 105 countries spanning 1971–2009. In addition, the analysis of the time series properties of urbanization has implications both for modelers and for understanding the urbanization phenomenon. We consider total, industrial, and residential aggregations of electricity consumption per capita, three income-based panels, and three geography-based panels for non-OECD countries. The panel unit root, cointegration, and causality tests used account for cross-sectional dependence, nonstationarity, and heterogeneity – all of which are present in the data set. We cannot reject pervasively Granger causality in the urbanization to electricity consumption direction. However, the causality finding that is both the strongest and most similar across the various panels is that of long-run Granger causality from electricity consumption to urbanization. In other words, the employment and quality of life opportunities that access to electricity afford likely encourage migration to cities, and thus, cause urbanization. Also, nearly all countries’ urbanization series contained structural breaks, and the most recent post-break annual change rates suggested that nearly all countries’ rates of urbanization change were slowing. Lastly, future modeling work on energy consumption or carbon emissions should consider subnational scales of analysis, and focus on measures of urban density or urban form rather than national urbanization levels.  相似文献   

Prediction of non-cavitation propeller noise in time domain     

叶金铭  熊鹰  肖昌润  毕毅 《中国海洋工程》2011,25(3):531-538

The blade frequency noise of non-cavitation propeller in a uniform flow is analyzed in time domain. The unsteady loading (dipole source) on the blade surface is calculated by a potential-based surface panel method. Then the time- dependent pressure data is used as the input for Ffowcs Williams-Hawkings formulation to predict the acoustics pressure. The integration of noise source is performed over the true blade surface rather than the nothickness blade surface, and the effect of hub can be considered. The noise characteristics of the non-cavitation propeller and the numerical discretization forms are discussed.  相似文献   

开发区土地要素对经济增长的贡献——基于江苏省面板数据的估计与测算     

陈伟  严长清  吴群  李永乐 《地域研究与开发》2011,30(5)

通过构建含有土地要素的生产函数,并与面板数据模型相结合,分析了土地要素对江苏省开发区经济增长的作用。结果显示:(1)江苏省开发区整体正处于规模报酬递增阶段,苏南处于规模报酬不变阶段,苏中、苏北处于规模报酬递增阶段;(2)土地要素对开发区经济增长有正面的推动作用,但开发区经济增长对资本要素更为敏感;(3)土地要素容易被其他要素替代,尤其容易被资本替代;(4)固定资产投资仍是开发区经济增长的主要推动力。未来一段时间内,土地要素的作用将继续削弱,资本要素仍然起到主要作用,土地集约利用水平将不断提高。  相似文献