12Cr2Mo,14CrMo和15CrMo钢的生产流程为铁水-110 t BOF—LF—VD-300 mm×（1700~2400）mm板坯CC工艺。分析了钢中碳含量,Mn/S,结晶器倒锥度,结晶器冷却工艺和保护渣,浸入式水口插入深度等因素对连铸板坯表面纵裂的影响。通过将优化...12Cr2Mo,14CrMo和15CrMo钢的生产流程为铁水-110 t BOF—LF—VD-300 mm×（1700~2400）mm板坯CC工艺。分析了钢中碳含量,Mn/S,结晶器倒锥度,结晶器冷却工艺和保护渣,浸入式水口插入深度等因素对连铸板坯表面纵裂的影响。通过将优化前3种钢的结晶器倒锥度1.10优化成12Cr2Mo钢1.20,14CrMo钢1.15,15CrMo钢1.10,浸入式水口的插入深度由原先的170~180 mm调整到140~150 mm,使用粘度较低的保护渣（碱度1.25,1300℃粘度0.129 Pa·s）,以增加渣液的流动性,连铸板坯表面纵裂缺陷得到了有效的控制,纵裂率由原先的8.9%降低到优化后的3.2%。展开更多
Two novel constituents were isolated from the roots of Chinese medicinal herbs, Salvia miltiorrhiza. Their structures were determined by spectroscopic technique. The compounds were named 13,14-dihydroxy-15-methyl-benz...Two novel constituents were isolated from the roots of Chinese medicinal herbs, Salvia miltiorrhiza. Their structures were determined by spectroscopic technique. The compounds were named 13,14-dihydroxy-15-methyl-benzo[2,3-a]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(1) and 16-methyl-tropono[2,3-c]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(2).展开更多
介绍一种主要为室内定位提供测距基础的系统。该系统由两个对等的节点组成,节点1发送通过无线发出的同步握手信号,节点2收到同步信号后开始计时并回应握手信号,节点1确认握手成功后开始发送声波脉冲信号,节点2收到脉冲信号后停止计时,...介绍一种主要为室内定位提供测距基础的系统。该系统由两个对等的节点组成,节点1发送通过无线发出的同步握手信号,节点2收到同步信号后开始计时并回应握手信号,节点1确认握手成功后开始发送声波脉冲信号,节点2收到脉冲信号后停止计时,定时器的时间就是声波在空气中的传播时间,进而确定点和点之间的距离。节点主要是由声波发射接收电路、CC1100无线电模块和STC12C5A0S2单片机等组成。STC12C5A0S2内部带有捕获定时器的功能,能准确地抓住定时器的值。声波发射接收电路主要由NE555,LM386和NE5532构成,能高频喇叭发送和接收10.25 k Hz声波信号。系统在测试的过程中,随着距离的增大,误差会有所加大,在10 m范围内误差小于10%,可以满足定位测距的需求。在实际的应用过程中还可以通过系统标定等数据处理手段,进一步提高测量精度,满足更高的测距要求。展开更多
文摘Two novel constituents were isolated from the roots of Chinese medicinal herbs, Salvia miltiorrhiza. Their structures were determined by spectroscopic technique. The compounds were named 13,14-dihydroxy-15-methyl-benzo[2,3-a]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(1) and 16-methyl-tropono[2,3-c]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(2).
文摘介绍一种主要为室内定位提供测距基础的系统。该系统由两个对等的节点组成,节点1发送通过无线发出的同步握手信号,节点2收到同步信号后开始计时并回应握手信号,节点1确认握手成功后开始发送声波脉冲信号,节点2收到脉冲信号后停止计时,定时器的时间就是声波在空气中的传播时间,进而确定点和点之间的距离。节点主要是由声波发射接收电路、CC1100无线电模块和STC12C5A0S2单片机等组成。STC12C5A0S2内部带有捕获定时器的功能,能准确地抓住定时器的值。声波发射接收电路主要由NE555,LM386和NE5532构成,能高频喇叭发送和接收10.25 k Hz声波信号。系统在测试的过程中,随着距离的增大,误差会有所加大,在10 m范围内误差小于10%,可以满足定位测距的需求。在实际的应用过程中还可以通过系统标定等数据处理手段,进一步提高测量精度,满足更高的测距要求。
