1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of silicon nitri...1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of silicon nitride bonded silicon carbide bricks.展开更多
为解决高校节能监管系统配电站分布离散,各站内计量点规模不大时的远程集抄问题,以STM32F103处理器为核心,扩展了DL/T645-2007协议的定义,设计支持3级中继功能的电力载波(power line carrier,PLC)小型路由器。路由器以载波芯片为圆心,...为解决高校节能监管系统配电站分布离散,各站内计量点规模不大时的远程集抄问题,以STM32F103处理器为核心,扩展了DL/T645-2007协议的定义,设计支持3级中继功能的电力载波(power line carrier,PLC)小型路由器。路由器以载波芯片为圆心,实际通信距离为半径,构成等效的直抄、一级中继、二级中继和三级中继蜂窝模型,并以此为基础,建立一个逻辑上以路由器为根节点,各级蜂窝覆盖圆为层次的多叉树遍历查询结构,实现了中继路由图的建立和自动中继转发抄表。所设计的中继技术在低压电力载波通信和智能水表远程集抄领域得到了成功应用,可以低成本地替代RS485以实现能耗系统的远程抄控。展开更多
Based on China National Standard of Soil Engineering Classification (GB/T 50145-2007) and the Unified Soil Classification System of American Society for Testing Materials (ASTM D-2478), two kinds of soil laboratory en...Based on China National Standard of Soil Engineering Classification (GB/T 50145-2007) and the Unified Soil Classification System of American Society for Testing Materials (ASTM D-2478), two kinds of soil laboratory engineering classification methods were discussed and analyzed from the aspects of the definition in particle fraction, classification of soil type and evaluation standard for soil gradation. There is a same limit of fine grains fraction in the two standards, and there are three main types of soil in GB/T 50145-2007 and two in ASTM D-2487. Different evaluation standards of gradation are put forward for gravels and sands in ASTM D-2487. Same criteria of A line, B line and controlling value of plastic index are in the plasticity chart of both standards.展开更多
智能电能表光通信模块的研究,在智能电网建设中发挥着重要作用。通过对EPON(以太网无源光网络)、PLC(电力载波通信)和WiMAX(全球微波互联接入)技术的对比分析,选择EPON作为智能电能表通信接入网技术,并设计了通信流程。基于QCA8829嵌入...智能电能表光通信模块的研究,在智能电网建设中发挥着重要作用。通过对EPON(以太网无源光网络)、PLC(电力载波通信)和WiMAX(全球微波互联接入)技术的对比分析,选择EPON作为智能电能表通信接入网技术,并设计了通信流程。基于QCA8829嵌入式芯片,在Redhat Linux 2.6.x开发平台上采用可接入EPON系统的光纤接口技术,实现了智能电能表主站与从站的通信系统。经测试表明,基于EPON智能电表光通信模块实现了智能电网配电侧信息全采集、全覆盖,并使远程电费控制及负载控制到户。展开更多
文摘1 Scope This standard specifies the definition, classifica- tion, technical requirements, test methods, quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of silicon nitride bonded silicon carbide bricks.
文摘为解决高校节能监管系统配电站分布离散,各站内计量点规模不大时的远程集抄问题,以STM32F103处理器为核心,扩展了DL/T645-2007协议的定义,设计支持3级中继功能的电力载波(power line carrier,PLC)小型路由器。路由器以载波芯片为圆心,实际通信距离为半径,构成等效的直抄、一级中继、二级中继和三级中继蜂窝模型,并以此为基础,建立一个逻辑上以路由器为根节点,各级蜂窝覆盖圆为层次的多叉树遍历查询结构,实现了中继路由图的建立和自动中继转发抄表。所设计的中继技术在低压电力载波通信和智能水表远程集抄领域得到了成功应用,可以低成本地替代RS485以实现能耗系统的远程抄控。
基金Supported by Projects of National Natural Science Foundation of China ( Nos. 40902077,41111120084,41172236)
文摘Based on China National Standard of Soil Engineering Classification (GB/T 50145-2007) and the Unified Soil Classification System of American Society for Testing Materials (ASTM D-2478), two kinds of soil laboratory engineering classification methods were discussed and analyzed from the aspects of the definition in particle fraction, classification of soil type and evaluation standard for soil gradation. There is a same limit of fine grains fraction in the two standards, and there are three main types of soil in GB/T 50145-2007 and two in ASTM D-2487. Different evaluation standards of gradation are put forward for gravels and sands in ASTM D-2487. Same criteria of A line, B line and controlling value of plastic index are in the plasticity chart of both standards.
文摘智能电能表光通信模块的研究,在智能电网建设中发挥着重要作用。通过对EPON(以太网无源光网络)、PLC(电力载波通信)和WiMAX(全球微波互联接入)技术的对比分析,选择EPON作为智能电能表通信接入网技术,并设计了通信流程。基于QCA8829嵌入式芯片,在Redhat Linux 2.6.x开发平台上采用可接入EPON系统的光纤接口技术,实现了智能电能表主站与从站的通信系统。经测试表明,基于EPON智能电表光通信模块实现了智能电网配电侧信息全采集、全覆盖,并使远程电费控制及负载控制到户。
