20世纪80年代末,空间数据系统咨询委员会(CCSDS)提出了遥测包和遥控包的标准建议书及其概念原理的绿皮书。为解决遥测遥控包的部署和应用问题,统一星载包管理系统和地面监控支持的应用设计规格,欧空局(ESA)负责开发和推出了包应用标准(P...20世纪80年代末,空间数据系统咨询委员会(CCSDS)提出了遥测包和遥控包的标准建议书及其概念原理的绿皮书。为解决遥测遥控包的部署和应用问题,统一星载包管理系统和地面监控支持的应用设计规格,欧空局(ESA)负责开发和推出了包应用标准(PUS),成为所有ESA任务中的事实标准。2003年发布PUS的A版本(Telemetry and Telecommand Packet Utilization:ECSS-E-70-41A)获得了广泛的应用和成功。经过十几年的经验积累和总结,2016年又发布了PUS的C版本(ECSS-E-70-41C)。展开更多
For further understanding of self-heating of coal, we tested the reactions of seven different ranks of coal under inert atmosphere. In the test, 50-gram of coal sample ranged from 0.18 mm to 0.38 mm was put into a spe...For further understanding of self-heating of coal, we tested the reactions of seven different ranks of coal under inert atmosphere. In the test, 50-gram of coal sample ranged from 0.18 mm to 0.38 mm was put into a special designed copper reaction vessel and let pure nitrogen to flow into the coal sample from the bottom at a rate of 100 mL/min. The programmed temperature enclosure was run at a programmed rate of 0.8 ~C/min. The concentration of the carbon oxides and the coal temperature were tested. The results show that the coal reactions under inert atmosphere can generate CO and C02. The reactions under inert atmosphere are affected by coal ranks, initial pore structure of coal and sulfur content. For low ranks of coal, the productions of carbon oxides are piecewise. The coal temperature is lower than the surrounding temperature throughout the reactions under inert atmosphere, but it rises quickly and reaches a crossing point temperature in the later stage under dry-air atmosphere. Based on the analysis, it indicates the self-reaction of initial active groups exists in the self-heating of coal besides the reactions in the two parallel reactions model. Spontaneous combustion of coal is due to both the oxidation heat accumulation and the chain reaction. A new reaction model of self-heating of coal was orooosed.展开更多
Rope shovels are used to dig and load materials in surface mines. One of the main factors that influence the production rate and energy consumption of rope shovels is the performance of the operator. This paper presen...Rope shovels are used to dig and load materials in surface mines. One of the main factors that influence the production rate and energy consumption of rope shovels is the performance of the operator. This paper presents a method for evaluating rope shovel operators using the Multi-Attribute Decision-Making （MADM） model. Data used in this research were collected from an operating surface coal mine in the southern United States. The MADM model consists of attributes, their weights of importance, and alter- natives. Shovel operators are considered the alternatives, The energy consumption model was developed with multiple regression analysis, and its variables were included in the MADM model as attributes. Preferences with respect to min/max of the defined attributes were obtained with multi-objective opti- mization. Multi-objective optimization was conducted with the overall goal of minimizing energy con- sumption and maximizing production rate. Weights of importance of the attributes were determined by the Analytical Hierarchy Process （AHP）, The overall evaluation of operators was performed by one of the MADM models, i.e., PROMETHEE If. The research results presented here may be used by mining professionals to held evaluate the performance of rode shovel operators in surface mining.展开更多
文摘20世纪80年代末,空间数据系统咨询委员会(CCSDS)提出了遥测包和遥控包的标准建议书及其概念原理的绿皮书。为解决遥测遥控包的部署和应用问题,统一星载包管理系统和地面监控支持的应用设计规格,欧空局(ESA)负责开发和推出了包应用标准(PUS),成为所有ESA任务中的事实标准。2003年发布PUS的A版本(Telemetry and Telecommand Packet Utilization:ECSS-E-70-41A)获得了广泛的应用和成功。经过十几年的经验积累和总结,2016年又发布了PUS的C版本(ECSS-E-70-41C)。
基金Financial supports for this research provided by the National Natural Science Foundation of China (No. 50927403)the Fundamental Research Funds for the Central Universities (No.2011RC06)the Jiangsu Natural Science Foundation (No.BK2009004)
文摘For further understanding of self-heating of coal, we tested the reactions of seven different ranks of coal under inert atmosphere. In the test, 50-gram of coal sample ranged from 0.18 mm to 0.38 mm was put into a special designed copper reaction vessel and let pure nitrogen to flow into the coal sample from the bottom at a rate of 100 mL/min. The programmed temperature enclosure was run at a programmed rate of 0.8 ~C/min. The concentration of the carbon oxides and the coal temperature were tested. The results show that the coal reactions under inert atmosphere can generate CO and C02. The reactions under inert atmosphere are affected by coal ranks, initial pore structure of coal and sulfur content. For low ranks of coal, the productions of carbon oxides are piecewise. The coal temperature is lower than the surrounding temperature throughout the reactions under inert atmosphere, but it rises quickly and reaches a crossing point temperature in the later stage under dry-air atmosphere. Based on the analysis, it indicates the self-reaction of initial active groups exists in the self-heating of coal besides the reactions in the two parallel reactions model. Spontaneous combustion of coal is due to both the oxidation heat accumulation and the chain reaction. A new reaction model of self-heating of coal was orooosed.
文摘Rope shovels are used to dig and load materials in surface mines. One of the main factors that influence the production rate and energy consumption of rope shovels is the performance of the operator. This paper presents a method for evaluating rope shovel operators using the Multi-Attribute Decision-Making （MADM） model. Data used in this research were collected from an operating surface coal mine in the southern United States. The MADM model consists of attributes, their weights of importance, and alter- natives. Shovel operators are considered the alternatives, The energy consumption model was developed with multiple regression analysis, and its variables were included in the MADM model as attributes. Preferences with respect to min/max of the defined attributes were obtained with multi-objective opti- mization. Multi-objective optimization was conducted with the overall goal of minimizing energy con- sumption and maximizing production rate. Weights of importance of the attributes were determined by the Analytical Hierarchy Process （AHP）, The overall evaluation of operators was performed by one of the MADM models, i.e., PROMETHEE If. The research results presented here may be used by mining professionals to held evaluate the performance of rode shovel operators in surface mining.
