一种订货带有折扣的库存-生产模型的优化分析     

张秀  朱翼隽 《成都信息工程学院学报》2007,22(6):770-775

建立了由一个仓库和一个加工车间组成的库存-加工系统模型,该模型具有随机的需求过程和随机的供货时间.在假设允许缺货,订货带有批量折扣,并采用(s,S)库存策略的条件下,用排队论得到了该系统的无穷小生成元,给出了系统的费用函数,并对库存策略进行了优化分析.  相似文献   

Sources and flows of embodied CO2 emissions in import and export trade of China     

Yanmei Li  Jiafeng Fu  Zhanyun Ma  Bo Yang 《中国地理科学(英文版)》2014,24(2):220-230

This paper uses the Global Trade Analysis Project(version 7)database to calculate embodied CO2emissions in bilateral trade between China and other countries(regions)based on input-output methods.The sources and flows of embodied CO2emissions in import and export trade of China are analyzed.Results show that the flows of embodied CO2emissions in export trade are highly concentrated.The main flows to the United States(US)and Japan account for 1/4 and 1/7 of the total CO2emissions in export trade,respectively.Concentrated flows of total exports and small differences in export structure are the main reasons for the highly concentrated export trade.The sources of embodied CO2emissions in import trade have relatively low concentration.Taiwan Province of China,Hong Kong Special Administrative Region of China,US,Russia,Republic of Korea,and Japan account for around 7.72%–12.67%of the total embodied CO2emissions in import trade.The relative dispersion of import sources,the impact of the import structure,and the level of production technology in importing countries caused low concentration of CO2emissions in import trade.Overall,the embodied CO2emissions in the export trade of China are higher than those in import trade.As a result,production-based CO2emissions are higher than consumption-based CO2emissions.The difference of 8.96×108t of CO2,which comes mainly from the US,Japan,Germany,and the United Kingdom,accounts for 58.70%of the total difference.Some suggestions,such as improving energy efficiency,alerting high carbon-intensive industries transfer,expanding the market for sharing risks,and prompting the accounting system of consumption-based CO2emissions,are proposed based on the results.  相似文献   

Sensitivity of Climate Changes to CO_2 Emissions in China          下载免费PDF全文

CHEN Huo-Po  SUN Jian-Qi 《大气和海洋科学快报》2014,(5):422-427

In this study, the authors demonstrate that the Coupled Model Intercomparison Project Phase 5 （CMIP5） models project a robust response in changes of mean and climate extremes to warming in China. Under a scenario of a 1% CO2 increase per year, surface temperature in China is projected to increase more rapidly than the global average, and the model ensemble projects more precipitation （2.2%/℃）. Responses in changes of climate extremes are generally much stronger than that of climate means. The majority of models project a consistent re- sponse, with more warm events but fewer cold events in China due to CO2 warming. For example, the ensemble mean indicates a high positive sensitivity for increasing summer days （12.4%/℃） and tropical nights （26.0%/℃）, but a negative sensitivity for decreasing frost days （-4.7%/℃） and ice days （-7.0%/℃）. Further analyses indicate that precipitation in China is likely to become more extreme, featuring a high positive sensitivity. The sensitivity is high （2.4%/℃） for heavy precipitation days （〉 10 mm d l） and increases dramatically （5.3%/℃） for very heavy precipitation days （〉 20 mm d-1）, as well as for precipitation amounts on very wet days （10.8%/℃） and extremely wet days （22.0%/℃）. Thus, it is concluded that the more extreme precipitation events generally show higher sensitivity to CO2 warming. Additionally, southern China is projected to experience an increased risk of drought and flood occurrence, while an increased risk of flood but a decreased risk of drought is likely in other regions of China.  相似文献   

今年全球碳排放达356亿吨     

《地理教学》2013,(1):61

正全球气候变化研究领域最具权威的学术机构英国丁铎尔气候变化研究中心,北京时间3日凌晨在《自然》杂志《自然气候变化》专刊在线发表科研报告《维持全球升温低于2℃的挑战》。该报告公布了丁铎尔中心"全球碳计划"年度研究成果和最新研究数据,报告显示,全球二氧化碳排放在2012年进一步增加,达到创纪录的356亿吨,全球化石燃料燃烧排放比京都议定书设定的基线年1990年增加了58%。  相似文献   

Carbon emissions trends with optimal balanced economic growth of China and the USA and some abatement options for China     

Zheng Wang  Yongbin Zhu  Yongming Peng 《地理学报(英文版)》2013,23(6):991-1004

It is believed that the global CO2 emissions have to begin dropping in the near fu- ture to limit the temperature increase within 2 degrees by 2100. So it is of great concern to environmentalists and national decision-makers to know how the global or national CO2 emissions would trend. This paper presented an approach to project the future CO2 emissions from the perspective of optimal economic growth, and applied this model to the cases of China and the United States, whose CO2 emissions together contributed to more than 40% of the global emissions. The projection results under the balanced and optimal economic growth path reveal that the CO2 emissions will peak in 2029 for China and 2024 for the USA owing to their empirically implied pace of energy efficiency improvement. Moreover, some abatement options are analyzed for China, which indicate that 1） putting up the energy price will de- crease the emissions at a high cost; 2） enhancing the decline rate of energy intensity can significantly mitigate the emissions with a modest cost; and 3） the energy substitution policy of replacing carbon intensive energies with clean ones has considerable potential to alleviate emissions without compromising the economic development.  相似文献   

对我国发展低碳经济的思考与建议     

张所续 《西部资源》2010,(1):13-14

<正>从《京都议定书》到"巴厘岛路线图",各国在经济发展的同时,降低经济增长所带来的二氧化碳排放量已经成为全球共识。"低碳经济"概念最早出现在2003年的英国能源白皮书《我们能源的未来:创建低碳经济》,之后得  相似文献   

软岩洞室最优支护的广义SMP准则解与对比研究     

吕彩忠  孙亚丽 《岩土力学》2016,37(7):1956-1962

现有洞室最优支护设计均基于Mohr-Coulomb（简称M-C）准则,不能真实反映岩石强度的中间主应力效应以及围岩的三向不等应力状态。基于广义SMP准则和稳定蠕变J3准则,考虑中间主应力对岩石强度的提高作用,建立了软岩洞室最优支护力与围岩允许最大位移的理论解答。洞室最优支护解答对M-C准则、外接圆Drucker-Prager（简称D-P）准则均具有很好的拓展性,且工程实例验证了其正确性。研究结果表明：3种强度准则结果间的差异实际反映的是对中间主应力效应的不同考虑,M-C准则和外接圆D-P准则对应的结果是两个极端情况,推荐选用广义SMP准则解答;岩石长期强度是洞室最优支护设计的关键参数,围岩凝聚力与内摩擦角的影响亦很显著,应合理测定岩石的强度参数并充分考虑变异性。  相似文献   

列车运行振动对地铁隧道沉降监测系统的影响分析     

杨江  姜丹 《大地测量与地球动力学》2012,32(Z1):149-152

地铁隧道沉降监测系统主要用于自动、实时、连续的监测隧道沉降.通过振动干扰导入,利用环境模拟方法对系统进行了响应测试.实验结果表明列车运行时产生的振动干扰在系统监测允许误差范围内.  相似文献   

Industrial and agricultural effects on water environment and its optimization in heavily polluted area in Taihu Lake Basin, China   总被引：1，自引：0，他引：1  

ZHAO Haixia  YOU Bensheng  DUAN Xuejun  Stewart BECKY  JIANG Xiaowei 《中国地理科学(英文版)》2013,23(2):203-215

The deteriorating water quality in the Taihu Lake Basin has attracted widespread attention for many years, and is correlated with a sharp increase in the quantity of pollutant discharge such as agricultural fertilizers and industrial wastewater. In this study, several factors were selected for evaluating and regionalizing the water environmental capacity by ArcGIS spatial analysis, including geomorphologic characteristics, water quality goals, water body accessibility, water-dilution channels, and current water quality. Then, the spatial optimization of agriculture and industry was adjusted through overlay analysis, based on the balance between industrial space and water environmental capacity. The results show that the water environmental capacity gradually decreases from the west to the east, in contrast, the pollution caused by industrial and agricultural clustering is distributes along Taihu Lake, Gehu Lake and urban districts. The analysis of the agricultural space focuses on optimizing key protected areas of the Taihu Lake Basin, and the shores of Gehu Lake, optimally adjusting the second protected areas of the Taihu Lake Basin, and generally adjusting the urban areas of Changzhou and Wuxi cities. The analysis of industrial space focuses on optimizing the downtowns of Changzhou and Wuxi cities, optimally adjusting key protected areas and second protected areas of the Taihu Lake Basin, and generally adjusting the south and southwest of Gehu Lake. Lastly, some schemes of industrial and agricultural layouts and policies for the direction of industrial and agricultural development were proposed, reflecting a correlation between industry and agriculture and the water environment.  相似文献   

环境污染与防治     

《中国地理与资源文摘》2008,(4)

  相似文献