Using VAR-DCC-GARCH model,the literature on commodity price was extended by exploring the co-movement between Chinese nonferrous metal prices and global nonferrous metal prices represented by the nonferrous metal pric...Using VAR-DCC-GARCH model,the literature on commodity price was extended by exploring the co-movement between Chinese nonferrous metal prices and global nonferrous metal prices represented by the nonferrous metal prices from London Metal Exchange(LME).The results show that LME nonferrous metals prices still have a greater impact on Chinese nonferrous metals prices.However,the impact of Chinese nonferrous metals prices on LME nonferrous metals prices is still weak except for lead price.The co-movement of nonferrous metal prices between LME and China presents hysteretic nature,and it lasts for 7-8trading days.Furthermore,the co-movement between LME nonferrous metals prices and Chinese nonferrous metals prices has the characteristics of time-varying,and the correlation of lead prices between LME and China is the more stable than all other nonferrous metals prices.展开更多
Using a special TEM constant deflection device, the change in dislocation configuration ahead of a loaded crack tip before and after adsorption of Hg atoms and the initiation of liquid metal-induced nanocracks (LMIC) ...Using a special TEM constant deflection device, the change in dislocation configuration ahead of a loaded crack tip before and after adsorption of Hg atoms and the initiation of liquid metal-induced nanocracks (LMIC) have been observed. The results show that chemisorption of Hg atoms can facilitate dislocation emission, multiplication and motion. Nanocracks will be initiated in the dislocation-free zone (DFZ) or at the crack tip when chemisorption-facilitated dislocation emission, multiplication and motion reach a critical condition. On the basis of the available experimental evidence concerning liquid metal embnttlement (LME), a new mechanism for this phenomenon is considered. This involves the fact that the decrease in surface energy induced by chemisorption of Hg atoms results in a reduction in the critical stress intensity factors for dislocation emission and the resistance for dislocation motion. On the other hand, the plastic work and KIC will decrease with the decrease in the surface energy.展开更多
伦敦金属交易所((London Metal Exchange,以下简称LME)是国际金属交易中影响最大、交易品种最多、交易制度和配套设施最完善、最具权威性的金属交易所,其本质是一个远期现货市场。随着世界经济,尤其是金属行业的发展,LME不断改进相关规...伦敦金属交易所((London Metal Exchange,以下简称LME)是国际金属交易中影响最大、交易品种最多、交易制度和配套设施最完善、最具权威性的金属交易所,其本质是一个远期现货市场。随着世界经济,尤其是金属行业的发展,LME不断改进相关规则以顺应行业发展的需要,其包容、与时俱进的发展模式为市场参与者保值、交割、投资等创造了良好的条件。对LME交易规则进行研究,对其成功经验进行总结,可以为发挥国内期货市场功能服务实体经济提供借鉴,为我国期货市场的制度完善与创新发展提供借鉴。LME交易所之所以如此成功与其独特的制度设计和运作模式是分不开的,概括起来主要表现在会员结构、交易方式、合约安排及形式、风控体系、交割设置、交易策略以及纠纷解决机制等方面。而"对现货包容"是LME诸多规则设置的独到和成功之处,也是LME对"期货市场是现货市场补充"这一期货市场定位的完美诠释。展开更多
期货价格波动往往从发达地区期货市场向其他地区期货市场传导,使得其他地区的期货市场类似于发达地区期货市场的影子市场。本文以次贷危机发生时间为界将整个检验周期分为四个子阶段,以伦铜连三和沪铜连三的收盘价数据为研究对象,分别...期货价格波动往往从发达地区期货市场向其他地区期货市场传导,使得其他地区的期货市场类似于发达地区期货市场的影子市场。本文以次贷危机发生时间为界将整个检验周期分为四个子阶段,以伦铜连三和沪铜连三的收盘价数据为研究对象,分别选择各子周期最优Copula函数计算相关风险度量指标Co Va R,通过运用Copula-Co Va R模型来检验伦铜(LME)和沪铜(SHFE)期货市场之间的风险溢出关系,从而判断沪铜期货市场是否仍然是伦铜期货市场的影子市场。实证结果表明,伦铜和沪铜期货市场之间存在着积极的相互溢出效应,次贷危机后上海铜期货市场已经在一定程度上脱离了影子市场的范畴。展开更多
Objective: To investigate the allocation and management of large medical equipment (LME) in Xuzhou, Jiangsu Province, China, in order to make the best use of LME to meet the medical needs of local people. Methods: The...Objective: To investigate the allocation and management of large medical equipment (LME) in Xuzhou, Jiangsu Province, China, in order to make the best use of LME to meet the medical needs of local people. Methods: The research collected data from all hospitals that have LME in Xuzhou using questionnaire; 38 (97.4%) hospitals returned the questionnaire. Results: In Xuzhou, there are a total of 71 pieces of LME, each serving 126 600 people in an area of 163 km2. Sixty-two percent of them are allocated in urban areas, with Gini coefficient at 0.52, indicating imbalance and biased allocation of LME. Conclusion: The al- location of LME in Xuzhou is out of control and unfairly allocated.展开更多
9月20日,全球领先的工具加工机床制造商孚尔默(VOLLMER)集团,在其位于江苏太仓的生产基地举办了大型的技术开放日,这是集团延续数年、极具盛誉的技术交流活动VOLLMER VDays再度来到中国,以此盛会庆祝孚尔默在华二十周年。VOLLMER China ...9月20日,全球领先的工具加工机床制造商孚尔默(VOLLMER)集团,在其位于江苏太仓的生产基地举办了大型的技术开放日,这是集团延续数年、极具盛誉的技术交流活动VOLLMER VDays再度来到中国,以此盛会庆祝孚尔默在华二十周年。VOLLMER China VDays以技术演讲。展开更多
The acquisition method for planar 67Ga imaging has hardly changed for 30 years. In this study, in order to improve image quality and diagnostic accuracy, we take steps to optimize the acquisition method, and to choose...The acquisition method for planar 67Ga imaging has hardly changed for 30 years. In this study, in order to improve image quality and diagnostic accuracy, we take steps to optimize the acquisition method, and to choose a scatter correction. First, we acquired individual images from the 93 keV, 185 keV, and 300 keV photopeak;then the images were added together and compared to the individual images. Second, we compared results from a low-medium-energy (LME) collimator with those from a conventional medium-energy (ME) collimator. Also, we examined whether to combine the data from all three of the usual window locations (set about 93 keV, 185 keV, and 300 keV) or to use the data from only two. Third, we compared results from a conventional photopeak ± 10% window with those from a photopeak ± 9 keV window. Fourth, for scatter correction we compared results using the triple energy window (TEW) method with those using the multi-photopeak dual window (MDW) method. The phantoms studied were cold rods in a uniform background, and hot spheres within a cylinder containing uniformly radioactive water. The clinical study involved 22 patients with lung lesions. By the comparison by the contrast ratio in cold rods phantom, 15.6% is improved in LME (2 peaks) than ME (3 peaks), and 3.2% is improved in photopeak ± 9 keV than photopeak ± 10%, 10.2% is improved in TEW than MDW. However, the TEW scatter correction method recognized unstable to the contrast ratio in a clinical study. In addition, a body outline might disappear.展开更多
基金Project(71073177)supported by the National Natural Science Foundation of ChinaProject(12JJ4077)supported by the Natural Science Foundation of Hunan Province of ChinaProject(2012zzts002)supported by the Fundamental Research Funds of Central South University,China
文摘Using VAR-DCC-GARCH model,the literature on commodity price was extended by exploring the co-movement between Chinese nonferrous metal prices and global nonferrous metal prices represented by the nonferrous metal prices from London Metal Exchange(LME).The results show that LME nonferrous metals prices still have a greater impact on Chinese nonferrous metals prices.However,the impact of Chinese nonferrous metals prices on LME nonferrous metals prices is still weak except for lead price.The co-movement of nonferrous metal prices between LME and China presents hysteretic nature,and it lasts for 7-8trading days.Furthermore,the co-movement between LME nonferrous metals prices and Chinese nonferrous metals prices has the characteristics of time-varying,and the correlation of lead prices between LME and China is the more stable than all other nonferrous metals prices.
基金Project supported by the National Natural Science Foundation of China.
文摘Using a special TEM constant deflection device, the change in dislocation configuration ahead of a loaded crack tip before and after adsorption of Hg atoms and the initiation of liquid metal-induced nanocracks (LMIC) have been observed. The results show that chemisorption of Hg atoms can facilitate dislocation emission, multiplication and motion. Nanocracks will be initiated in the dislocation-free zone (DFZ) or at the crack tip when chemisorption-facilitated dislocation emission, multiplication and motion reach a critical condition. On the basis of the available experimental evidence concerning liquid metal embnttlement (LME), a new mechanism for this phenomenon is considered. This involves the fact that the decrease in surface energy induced by chemisorption of Hg atoms results in a reduction in the critical stress intensity factors for dislocation emission and the resistance for dislocation motion. On the other hand, the plastic work and KIC will decrease with the decrease in the surface energy.
文摘伦敦金属交易所((London Metal Exchange,以下简称LME)是国际金属交易中影响最大、交易品种最多、交易制度和配套设施最完善、最具权威性的金属交易所,其本质是一个远期现货市场。随着世界经济,尤其是金属行业的发展,LME不断改进相关规则以顺应行业发展的需要,其包容、与时俱进的发展模式为市场参与者保值、交割、投资等创造了良好的条件。对LME交易规则进行研究,对其成功经验进行总结,可以为发挥国内期货市场功能服务实体经济提供借鉴,为我国期货市场的制度完善与创新发展提供借鉴。LME交易所之所以如此成功与其独特的制度设计和运作模式是分不开的,概括起来主要表现在会员结构、交易方式、合约安排及形式、风控体系、交割设置、交易策略以及纠纷解决机制等方面。而"对现货包容"是LME诸多规则设置的独到和成功之处,也是LME对"期货市场是现货市场补充"这一期货市场定位的完美诠释。
文摘期货价格波动往往从发达地区期货市场向其他地区期货市场传导,使得其他地区的期货市场类似于发达地区期货市场的影子市场。本文以次贷危机发生时间为界将整个检验周期分为四个子阶段,以伦铜连三和沪铜连三的收盘价数据为研究对象,分别选择各子周期最优Copula函数计算相关风险度量指标Co Va R,通过运用Copula-Co Va R模型来检验伦铜(LME)和沪铜(SHFE)期货市场之间的风险溢出关系,从而判断沪铜期货市场是否仍然是伦铜期货市场的影子市场。实证结果表明,伦铜和沪铜期货市场之间存在着积极的相互溢出效应,次贷危机后上海铜期货市场已经在一定程度上脱离了影子市场的范畴。
文摘Objective: To investigate the allocation and management of large medical equipment (LME) in Xuzhou, Jiangsu Province, China, in order to make the best use of LME to meet the medical needs of local people. Methods: The research collected data from all hospitals that have LME in Xuzhou using questionnaire; 38 (97.4%) hospitals returned the questionnaire. Results: In Xuzhou, there are a total of 71 pieces of LME, each serving 126 600 people in an area of 163 km2. Sixty-two percent of them are allocated in urban areas, with Gini coefficient at 0.52, indicating imbalance and biased allocation of LME. Conclusion: The al- location of LME in Xuzhou is out of control and unfairly allocated.
文摘The acquisition method for planar 67Ga imaging has hardly changed for 30 years. In this study, in order to improve image quality and diagnostic accuracy, we take steps to optimize the acquisition method, and to choose a scatter correction. First, we acquired individual images from the 93 keV, 185 keV, and 300 keV photopeak;then the images were added together and compared to the individual images. Second, we compared results from a low-medium-energy (LME) collimator with those from a conventional medium-energy (ME) collimator. Also, we examined whether to combine the data from all three of the usual window locations (set about 93 keV, 185 keV, and 300 keV) or to use the data from only two. Third, we compared results from a conventional photopeak ± 10% window with those from a photopeak ± 9 keV window. Fourth, for scatter correction we compared results using the triple energy window (TEW) method with those using the multi-photopeak dual window (MDW) method. The phantoms studied were cold rods in a uniform background, and hot spheres within a cylinder containing uniformly radioactive water. The clinical study involved 22 patients with lung lesions. By the comparison by the contrast ratio in cold rods phantom, 15.6% is improved in LME (2 peaks) than ME (3 peaks), and 3.2% is improved in photopeak ± 9 keV than photopeak ± 10%, 10.2% is improved in TEW than MDW. However, the TEW scatter correction method recognized unstable to the contrast ratio in a clinical study. In addition, a body outline might disappear.
