A comparative analysis of multi-scalar regional inequality in China     

《Geoforum》2017

This paper investigates regional inequality across regions, provinces, prefectures, and counties in China from 1997 to 2010 using a comparative and multiscalar framework. Regional inequality is sensitive to geographic scales and regional heterogeneity. The year 2004 was a turning point for trends in inequality, when a new spatial regime started to emerge at the county-level in China. County-level inequality demonstrates a consistent upward trend despite a slight dip in 2005, which is different from a broad inverted U-shape trend at other geographic scales. Furthermore, intensifying inequalities are demonstrated between prefectures than within prefectures, within provinces than between provinces, and between regions than within regions. The underdeveloped Western region of China contributes the most to regional inequalities across counties and prefectures. Based on the heterogeneous characteristics of regional inequality, it is suggested that effective regional policies should adopt a geographic focus to reduce inequalities. Finally, a Markov chain technique is applied to predict the long-run properties of regional development in China. The results show that it is difficult for counties, prefectures and provinces to leapfrog from being less developed to well developed. This paper concludes that regional inequality in China in the long-run does not follow the neoclassical convergence hypothesis.  相似文献   

黄河流域水资源-能源-粮食的协同优化   总被引：3，自引：0，他引：3       下载免费PDF全文

彭少明  郑小康  王煜  蒋桂芹 《水科学进展》2017,28(5):681-690

黄河流域是中国重要能源和粮食主产区,然而水资源短缺已成为制约能源、粮食发展的关键要素。为优化流域水资源、能源、粮食之间的关系,引入协同学原理构建水资源-能源-粮食整体分析框架,建立具有总分结构、互馈关联的协同优化模型,采用多要素均衡智能算法,提出黄河流域粮食生产、能源开发与水资源调配一体优化的布局方案。结果表明,通过水资源-能源-粮食协同优化,2030年增加流域供水量23.98亿m3;优化了流域粮食生产布局,人均粮食产量提高12%;优选了能源产业规模和结构,煤炭开采、石油加工和火电总装机分别增加了2.86倍、4.08倍和0.80倍;在满足生活、生态环境用水的同时实现了粮食增收、能源增产。  相似文献   

深圳沿岸海域贝类重金属和贝类毒素污染状况分析          下载免费PDF全文

孙冉  王舟 《应用海洋学学报》2017,36(4):575-579

通过检测深圳沿岸海域7种贝类的重金属、麻痹性贝毒(PSP)和腹泻性贝毒(DSP)含量,了解其食用安全性.严格按照国家标准进行检测,采用SPSS 20.0对数据进行Kruskal-Wallis H检验和方差分析.结果表明:各种重金属和贝类毒素在样品中均有检出,汞污染状况良好;铜含量范围为0.52~109.65 mg/kg,超标率为13.67%;铅含量范围为0.01~3.60 mg/kg,超标率为68.35%;镉含量范围为0.015~7.807 mg/kg,超标率为53.96%.PSP和DSP检出率为100%,PSP含量范围为0.30~34.23 ug/100 g;DSP含量范围为1.88~38.41 ug/100 g.总体看来,样品铅、镉超标严重,不同种类贝类重金属含量具有差异且贝类毒素检出率较高,应引起有关部门的重视,加强该海域监测工作.  相似文献   

Food commodities, geographical knowledges and the reconnection of production and consumption: The case of naturally embedded food products   总被引：1，自引：0，他引：1  

Carol Morris  James Kirwan 《Geoforum》2010,41(1):131-143

This paper focuses on a particular group of food commodities, associated with the wider turn to ‘alternative food networks’, that are described as ‘naturally embedded food products’ (NEFPs). These are commodities (specifically meats and cheeses) that utilise grassland biodiversity as an input into production to positively influence, in various ways, the final qualities of the commodity. Building on the geographical literature on commodity circuits and analysing data derived from NEFP promotional materials and focus groups with urban and rural residents in the UK, the paper interrogates the geographical knowledges that are deployed by producers in the promotion of NEFPs and how these knowledges are accommodated and contested by consumers as they bring their own geographical knowledges to the interpretation of these commodities. The paper undertakes this task in order to problematise the extent to which alternative food networks in general and NEFPs in particular are bringing about a reconnection of producers and consumers and, concomitantly, a defetishisation of food, as is claimed for them by many of their policy and academic proponents. In the process the paper reveals how the food commodities associated with alternative food networks entail the creation of new and rival fetishes paradoxically as a result of efforts to ‘thicken connections’ between the production and consumption of food.  相似文献   

北京电子信息产业及其价值链空间分布特征研究   总被引：4，自引：1，他引：3  

卢明华  李丽 《地理研究》2012,31(10):1861-1871

作为主导产业部门之一的电子信息产业在北京具有较强的产业实力及较好的发展前景。本研究通过分析电子信息产业和大型电子信息企业主要价值链环节在北京的分布情况, 总结了电子信息产业及其价值链的空间分布特征。研究发现:北京市电子信息产业郊区化趋势明显且呈集聚分布, 大型电子信息企业主要价值链环节也呈集聚分布, 生产环节的远郊化明显, 呈现多中心空间结构;北京市主要电子信息产业集聚区呈现明显的功能分工、大型电子信息企业主要价值链环节呈现明显的区域分工。  相似文献   

旅行社供应链管理模式研究     

包曾婷  王虹 《云南地理环境研究》2012,24(1):92-97

随着旅游业的快速发展及旅游企业竞争的日趋激烈,旅行社供应链管理已成为旅行社与其他旅游企业提升市场核心竞争力,实现行业利润最大化的重要途径。在对旅行社实施供应链管理必要性分析的基础上,构建了旅行社供应链管理模式,并对其运作机理分为两个流程进行详细分析,以期为旅行社实施供应链管理提供一定的借鉴,推动整个行业的健康发展。  相似文献   

Photochemistry in the Arctic Free Troposphere: Ozone Budget and Its Dependence on Nitrogen Oxides and the Production Rate of Free Radicals     

Craig Stroud  Sasha Madronich  Elliot Atlas  Christopher Cantrell  Alan Fried  Brian Wert  Brian Ridley  Fred Eisele  Lee Mauldin  Richard Shetter  Barry Lefer  Frank Flocke  Andy Weinheimer  Mike Coffey  Brian Heikes  Robert Talbot  Donald Blake 《Journal of Atmospheric Chemistry》2004,47(2):107-138

Local ozone production and loss rates for the arctic free troposphere (58–85° N, 1–6 km, February–May) during the TroposphericOzone Production about the Spring Equinox (TOPSE) campaign were calculated using a constrained photochemical box model. Estimates were made to assess the importance of local photochemical ozone production relative to transport in accounting for the springtime maximum in arctic free tropospheric ozone. Ozone production and loss rates from our diel steady-state box model constrained by median observations were first compared to two point box models, one run to instantaneous steady-state and the other run to diel steady-state. A consistent picture of local ozone photochemistry was derived by all three box models suggesting that differences between the approaches were not critical. Our model-derived ozone production rates increased by a factor of 28 in the 1–3 km layer and a factor of 7 in the 3–6 kmlayer between February and May. The arctic ozone budget required net import of ozone into the arctic free troposphere throughout the campaign; however, the transport term exceeded the photochemical production only in the lower free troposphere (1–3 km) between February and March. Gross ozone production rates were calculated to increase linearly with NO_x mixing ratiosup to 300 pptv in February and for NO_x mixing ratios up to 500 pptv in May. These NO_x limits are an order of magnitude higher thanmedian NO_x levels observed, illustrating the strong dependence ofgross ozone production rates on NO_x mixing ratios for the majority of theobservations. The threshold NO_x mixing ratio needed for netpositive ozone production was also calculated to increase from NO_x 10pptv in February to 25 pptv in May, suggesting that the NO_x levels needed to sustain net ozone production are lower in winter than spring. This lower NO_x threshold explains how wintertime photochemical ozone production can impact the build-up of ozone over winter and early spring. There is also an altitude dependence as the threshold NO_x neededto produce net ozone shifts to higher values at lower altitudes. This partly explains the calculation of net ozone destruction for the 1–3 km layerand net ozone production for the 3–6 km layer throughout the campaign.  相似文献   

TM图像中桥梁目标识别方法的研究   总被引：18，自引：3，他引：15  

吴皓  刘政凯  张荣 《遥感学报》2003,7(6):478-484

提出了一种新的TM图像中桥梁目标的识别方法。算法充分利用了TM图像的特点,在底层处理中运用形态学的方法提取出潜在桥梁目标;在中层处理中使用链码表示目标并提取其特征参数;最后在高层处理中进行桥梁识别和一些后处理。算法识别速度快、准确率高,整个算法可以进行自动的识别,也可以有少量人工干预使得算法更稳健。实验证明该算法对于TM图像中的桥梁识别是很有效的。  相似文献   

丘陵山区食物生产变化规律——以江西省为例     

吕爱清  邱爱保  卞新民  杜国平  陈路扬 《山地学报》2006,24(4):459-465

1978-2003年江西食物生产总量与食物生产要素保障度呈高度正相关（0．885），这表明江西食物生产总量受生产要素投入驱动，资源因子锐减是导致2000-2003年江西食物总量下降的主要原因。洪涝灾害面积、低温灾害面积、洪涝绝收面积和低温绝收面积是导致自然灾害的强驱动因子，干旱灾害面积、干旱绝收面积、风雹灾害面积和风雹绝收面积是导致自然灾害的次强驱动因子。灌溉面积、农业劳动力等食物生产要素的波动与同期食物生产波动具有显著关联性，其显著关联序为：灌溉面积波动〉总种植面积波动〉农业劳动力波动〉农业资金投入波动〉化肥用量波动。1978-2003年江西食物波动指数与全要素相对生产率（TFRP）的走势基本一致，表现为食物波动平稳或食物呈较大正波动时TFRP较高，生产要素配置合理；而食物呈较大负波动时TFRP往往偏低。  相似文献   

全球铜资源状况及未来五年中国铜资源战略     

陈甲斌 《江苏地质》2006,30(4):314-320

铜是国民经济发展中应用最为广泛的重要基础原材料之一,但长期以来,我国铜资源生产不能满足国内消费需求,供需缺口较大,从而约束铜产业链协调发展,需要通过国际市场加以平衡。为了确保国民经济发展对铜产品的消费需要,保障铜资源长期稳定安全供应,进一步夯实铜产业链协调发展的资源基础,研究制定我国铜资源战略已势在必行。在分析国内外铜资源利用现状、供需格局及经济发展对铜资源的消费需求等方面基础上,构建了我国铜资源的发展战略,并对我国铜工业的发展提出了一些建议。  相似文献