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Yuepeng Zhou Xiaoping Shi Dengyan Ji Xianlei Ma Satish Chand 《Natural resources forum》2019,43(2):95-110
The decentralization of property rights is the focus of the forest tenure reforms in several developing countries. In China, it was achieved by the launch of a new round of collective forest tenure reform beginning in 2003, which provided farmers with more integrated and secure forestland rights. Drawing on household data collected in Jiangxi province in 2011 and 2013, this paper examines the impacts of households’ recognition of property rights and improved tenure security on forestland rental activities. Our empirical results show that households with higher perceptions of more complete use rights and mortgage rights have a lower probability and intensity of renting‐in land, while households with lower expectations of future forestland redistribution or expropriation are more likely to rent in forestland and more of it. These results imply that the development of a forestland rental market leading to better forest management requires an integrated forestland management approach consisting of decentralization of property rights and village governance. In particular, the central government may further clarify the rights and obligations affiliated to forestland ownership, contractual rights, and management rights; while the village collective may shift from direct intervention in the integrity and security of forestland rights to the supervision and protection of decentralized forestland rights to increase efficiency from the decentralization of property rights. 相似文献
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Forecasting iron ore import and consumption of China using grey model optimized by particle swarm optimization algorithm 总被引:1,自引:0,他引:1
The iron and steel industry plays a fundamental role in a country's national economy, especially in developing countries. China is the largest iron ore consumption market in the world. However, because of limited domestic iron ore resources, a large proportion of iron ore is imported from other countries. Faced with the conflict between the iron ore supply shortage and the growing demand, it is necessary for the government to predict imports and total consumption. This paper develops a high-precision hybrid model based on grey prediction and rolling mechanism optimized by particle swarm optimization algorithm. We use the China Statistical Yearbook (1996–2011) as our database to test the efficiency and accuracy of the proposed method. According to the experimental results, the proposed new method clearly can improve the prediction accuracy of the original grey model. Future projections have also been done for iron ore imports and total consumption in China in the next five years. 相似文献
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A triple-objective optimal sizing method based on a dynamic strategy is presented for an islanded hybrid energy microgrid, consisting of wind turbine, solar photovoltaic, battery energy storage system and diesel generator. The dynamic strategy is given based on a dynamic complementary coordination between two different master-slave control modes for maximum renewable energy utilization. Combined with the proposed strategy, NSGA-II-based optimization program is applied to the sizing optimization problem with triple different objectives including the minimization of annualized system cost, the minimization of loss of power supply probability and the maximization of utilization ratio of renewable energy generation. The sizing results and the proposed strategy are both compared and analyzed to validate the proposed method in a real case of an islanded hybrid energy microgrid on Dong’ao Island, China. 相似文献
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分布在世界各地的K/T界面剖面,尽管形成环境各异,但彼此之间的岩石矿物特征却有许多共同之处。对于大多数剖面来说,界面粘土层的底都普遍存在着一个结构特别的冲击层。冲击层的厚度在全球的分布并不均匀,北美和加勒比海地区可达2~50cm,而其它地区则只有几厘米。冲击层的厚度可能反映了距离撞击坑的远近。详细的岩石与矿物学研究结果表明,在北美和加勒比海地区冲击层实际上具有双层结构特征。上面的一层称为火球层,除了富集Ir和其它地外指示元素外,还含有大量的烟灰和富Ni镁铁尖晶石。下面的溅射层则含有大量的冲击玻璃球粒(玻璃陨石)和冲击变质矿物。K/T界面冲击层的发现为Ir异常的地外撞击成因解释提供了更为直接的物理证据。 相似文献
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通过对催化裂化装置生产过程中职业病危害因素调查,找出职业病危害的关键控制点,并提出防护要求。 相似文献
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