格库铁路青海段大部分处于偏远无人区,且区间无轨道电路,为检测断轨与减轻维护压力,设计了基于轨道电路原理的实时断轨检测系统。利用远距离无线电(Long Range Radio,LoRa)设计链式通信系统来传输报文,并进行理论指标验证;又在均匀传输...格库铁路青海段大部分处于偏远无人区,且区间无轨道电路,为检测断轨与减轻维护压力,设计了基于轨道电路原理的实时断轨检测系统。利用远距离无线电(Long Range Radio,LoRa)设计链式通信系统来传输报文,并进行理论指标验证;又在均匀传输线基础上得到轨道电路功率估计算式;随后,搭建信号发送系统,在室内利用模拟钢轨盘验证了使用功率估计区分断轨的可行性;最后,结合室内实验和链式通信系统搭建样机,现场测试验证了轨道电路功率估计算式的准确性。实验表明:利用轨道电路功率估计可有效、准确地完成断轨检测,室内和室外功率计算最小误差分别达1.06%和5.2%。相较于传统钢轨探伤方式,更适合在无人区非集中区段部署。展开更多
Human activities in the marginal zone of the Changtang Plateau(CTP)uninhabited area are important research topics in China and globally.Based on the core-periphery theory of geography,this paper selected three countie...Human activities in the marginal zone of the Changtang Plateau(CTP)uninhabited area are important research topics in China and globally.Based on the core-periphery theory of geography,this paper selected three counties in the marginal zone of the CTP uninhabited area with significant transitional physical geography features and socio-economic conditions as case areas.We used the data set of settlement patches identified by visual interpretation in Google Earth Pro,combining them with field survey data to study the evolution of human settlements on the CTP,the characteristics of settlement layout,and their socio-economic roots.The study found that:(1)Since the democratic reform in Tibet,the production mode of herders on the CTP has transitioned from four-season nomadic herding to cold-season sedentary grazing,warm-season rotational grazing,and then to a combination of sedentary grazing and forage supplementation.In structural changes of grassroots organizations,village boundaries were clarified,grazing ranges were fixed,and settlement systems were formed.(2)On a large scale,the settlement layout on the CTP showed a certain degree of agglomeration in local areas,but the settlements’spatial agglomeration decreased as the observation scale decreased.The settlement size structure matched the typical rank-size rule of rural settlements.(3)The settlement layout of the CTP showed significant traffic lines and dominant location orientation.These orientation characteristics revealed“core-periphery”regional differences.Changes in production conditions,such as artificial grass cultivation and part-time employment,affected the dependence on traditional grazing points.Settlements moved from resource dependence to dependence on multiple elements,such as resources and facilities.The religious,cultural heritage of the sacred mountains,lakes,and temples influenced the settlement layout,leading to clustering in local areas and to group format.This study expands our understanding of the settlement pattern in the marginal zone 展开更多
文摘格库铁路青海段大部分处于偏远无人区,且区间无轨道电路,为检测断轨与减轻维护压力,设计了基于轨道电路原理的实时断轨检测系统。利用远距离无线电(Long Range Radio,LoRa)设计链式通信系统来传输报文,并进行理论指标验证;又在均匀传输线基础上得到轨道电路功率估计算式;随后,搭建信号发送系统,在室内利用模拟钢轨盘验证了使用功率估计区分断轨的可行性;最后,结合室内实验和链式通信系统搭建样机,现场测试验证了轨道电路功率估计算式的准确性。实验表明:利用轨道电路功率估计可有效、准确地完成断轨检测,室内和室外功率计算最小误差分别达1.06%和5.2%。相较于传统钢轨探伤方式,更适合在无人区非集中区段部署。
基金The Second Comprehensive Scientific Investigation and Research Project of the Qinghai-Tibet Plateau,No.2019QZKK1007The Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA20010102。
文摘Human activities in the marginal zone of the Changtang Plateau(CTP)uninhabited area are important research topics in China and globally.Based on the core-periphery theory of geography,this paper selected three counties in the marginal zone of the CTP uninhabited area with significant transitional physical geography features and socio-economic conditions as case areas.We used the data set of settlement patches identified by visual interpretation in Google Earth Pro,combining them with field survey data to study the evolution of human settlements on the CTP,the characteristics of settlement layout,and their socio-economic roots.The study found that:(1)Since the democratic reform in Tibet,the production mode of herders on the CTP has transitioned from four-season nomadic herding to cold-season sedentary grazing,warm-season rotational grazing,and then to a combination of sedentary grazing and forage supplementation.In structural changes of grassroots organizations,village boundaries were clarified,grazing ranges were fixed,and settlement systems were formed.(2)On a large scale,the settlement layout on the CTP showed a certain degree of agglomeration in local areas,but the settlements’spatial agglomeration decreased as the observation scale decreased.The settlement size structure matched the typical rank-size rule of rural settlements.(3)The settlement layout of the CTP showed significant traffic lines and dominant location orientation.These orientation characteristics revealed“core-periphery”regional differences.Changes in production conditions,such as artificial grass cultivation and part-time employment,affected the dependence on traditional grazing points.Settlements moved from resource dependence to dependence on multiple elements,such as resources and facilities.The religious,cultural heritage of the sacred mountains,lakes,and temples influenced the settlement layout,leading to clustering in local areas and to group format.This study expands our understanding of the settlement pattern in the marginal zone
