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71.
72.
This paper investigates convergence patterns among China's provinces using GDP data for the period 1952–97. We analyze convergence behaviour on the basis of Markov chains proposed by Quah (1993 ) and the generalized entropy decomposition proposed by Shorrocks (1980, 1984 ). Both sets of results show similar evidence of convergence within the pre‐defined geo‐economic sub‐regions, but no evidence is found of convergence between the sub‐regions. This finding has important policy implications for regional economic development in China. JEL classification: C33, E20, O47.  相似文献   
73.
历史上每一次土地制度、赋税制度和行政管理体制的较大规模变革,都是同步配套进行的,有其相互关联性和一般规律性.新中国成立后,在城乡对立的二元经济社会结构中,农村集体土地制度、农民收入分配制度和农村行政管理体制自成一体,封闭运行,城乡差别日益扩大,同时附带了明显的"外部性"问题.改革开放以来,国家新的农村政策导向和农村新经济因素的产生,正在促使中国经济社会结构由农村农业、城市工业的二元结构向城市、小城镇、乡村多种产业组合和多样化的生活方式并存的三元结构转换,终将形成城乡一体化发展的新格局.农村集体土地制度、国民收入分配制度和国家行政管理体制,必须要按照社会主义市场经济发展的基本规律和城乡经济社会协调发展的新要求,进行一次最彻底的整体性配套改革.  相似文献   
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75.
Construction kits have played a significant part in nurturing the growth and development of the minds and manipulation-based skills of children (and adults) in formal and non-formal education settings. These kits have origins rooted in the representation of the built world and now have a diversity of form and function, including technical versions with moving parts. This article examines some of the historically based ideas that lie behind the role that kits may have in terms of physical modelling. The article traces the transformation of kits from simple bricks and blocks into more complicated pieces for space-filling and achieving the transfer of forces and motion. This transformation occurred during the Victorian era when the influence of the ideas of educationalists and, perhaps rather strangely, exponents of early aviation, played major roles in determining the diversity of forms of construction kit and modelled possibilities that are now to be seen in classrooms and homes. The article ends with a review of some of the lessons from the past and present that will need to be considered in relation to concrete modelling in schools for the future. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
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77.
In this article the impact of technology education, as a new learning area (subject) in the curriculum, on in-service teacher education in South Africa is described in order to ascertain the extent of the impact. The research on which this article is based draws on a variety of experiences and observations in the field at grassroots level (in particular an outreach project in rural communities). The envisaged impact of technology education on South African schools, communities, teacher educators and teachers, the range of in-service teacher education that is required, and the impacts in urban and rural areas are discussed. Finally a number of concluding remarks are made about the extent of the impact of the inclusion of technology education in the new National Curriculum Statement and whether the situation has changed since the implementation of a pilot technology education project in 1998. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
78.
生命周期评价方法及其应用   总被引:6,自引:0,他引:6  
介绍了生命周期评价的目的、意义和基本方法,并运用该方法对燃煤发电、废纸造纸、废旧塑料气化发电等几种不同工业过程的环境影响进行了分析。  相似文献   
79.
In rational, efficiently functioning and complete markets, returns on derivative and underlying securities should be perfectly contemporaneously correlated. Due to market imperfections, one of these markets may reflect information faster. The use of high-frequency data and the choice for a small unit time interval to measure these lead-lag relations comes at the cost of some or many missing observations, causing traditional estimators to either under- or overestimate covariances and correlations. We use a new estimator to estimate lead-lag relationships between the cash AEX index, options and futures. We find that futures returns lead both options and cash index returns by approximately 10 minutes. The relationship between options and the cash market is not completely unidirectional.  相似文献   
80.
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