中国散裂中子源(China Spallation Neutron Source,CSNS)中的多功能反射谱仪采用二维多丝正比室探测器(Multi-Wire Proportional Chamber,MWPC)来获取入射中子的位置信息。本文介绍了一种结构简单的MWPC位置读出方法。该方法采用挪威ID...中国散裂中子源(China Spallation Neutron Source,CSNS)中的多功能反射谱仪采用二维多丝正比室探测器(Multi-Wire Proportional Chamber,MWPC)来获取入射中子的位置信息。本文介绍了一种结构简单的MWPC位置读出方法。该方法采用挪威IDEAS公司的64通道电荷灵敏专用集成电路(Application Specific Integrated Circuit,ASIC)VA64tap2.1,克服了传统方法硬件复杂、功耗大、成本高的缺点。另外,系统可通过测量阳极电荷量区分中子和γ射线,提高测量精度。在现有条件下对读出系统进行测试,测试结果表明:系统能完成读出任务,且所选ASIC芯片功耗低(每通道0.3 m W)、噪声小(<0.35 f C)、动态范围大(-200–+160 f C)、集成度高(单片64通道),可用于MWPC探测器的位置读出。展开更多
The exploration of ecological safety in tourism sites can provide a concrete path for sustainable tourism development in a region.Based on the“Driver-Pressure-State-Impact-Response”(DPSIR)model,we constructed an ind...The exploration of ecological safety in tourism sites can provide a concrete path for sustainable tourism development in a region.Based on the“Driver-Pressure-State-Impact-Response”(DPSIR)model,we constructed an index system for the evaluation of tourism ecological security(TES)in the Silk Road Economic Belt(SREB)from 2005 to 2020.This index system was used to explore the characteristics of spatial and temporal dynamic evolution with the help of entropy weight TOPSIS method,dynamic index of TES and Markov probability transfer matrix,and a standard deviational ellipse(SDE)model and GM(1,1)model were constructed for spatial pattern analysis and prediction.The results indicate four key aspects of this system.(1)In terms of spatiotemporal evolution,the tourism ecological safety index(TESI)of the SREB increased,the TES levels of the northwestern and southwestern provinces and cities differed significantly,and the quality conditions of TES in the southwestern provinces and cities were better than in the northwest.(2)In terms of dynamic evolutionary characteristics,the speed of change at each level of the SREB was slow,but the level of TES has improved.The TES level has not shifted by leaps and bounds,and the shifts in the level type show“path dependence”and“self-locking”effects.(3)In terms of spatial and temporal distribution patterns,the spatial pattern of TES in the SREB is a“northwest-southeast”movement trend,and the spatial distribution appeared as“aggregation”from 2005 to 2020.The prediction results show that the center of gravity of TES in the SREB will shift to the southeast from 2025 to 2035,and the spatial spillover effect will be reduced.(4)In terms of driving factors,the number of star-rated hotels,and the amounts of industrial wastewater emissions,tourism foreign exchange earnings,forest coverage,and other parameters are the key factors affecting TES,and the booming tourism industry requires the interconnection and interpenetration of various factors.The results of this study can provide a reference for tourism development and ecological environmental protection in the Silk Road Economic Belt.展开更多
文摘中国散裂中子源(China Spallation Neutron Source,CSNS)中的多功能反射谱仪采用二维多丝正比室探测器(Multi-Wire Proportional Chamber,MWPC)来获取入射中子的位置信息。本文介绍了一种结构简单的MWPC位置读出方法。该方法采用挪威IDEAS公司的64通道电荷灵敏专用集成电路(Application Specific Integrated Circuit,ASIC)VA64tap2.1,克服了传统方法硬件复杂、功耗大、成本高的缺点。另外,系统可通过测量阳极电荷量区分中子和γ射线,提高测量精度。在现有条件下对读出系统进行测试,测试结果表明:系统能完成读出任务,且所选ASIC芯片功耗低(每通道0.3 m W)、噪声小(<0.35 f C)、动态范围大(-200–+160 f C)、集成度高(单片64通道),可用于MWPC探测器的位置读出。
基金The Scientific Research Fund Project of Yunnan Education Department(2021J0592)The Yunnan University of Finance and EconomicsProgramme(2022D13)The Graduate Student Innovation Fund Project of Yunnan University of Finance and Economics(2022YUFEYC10).
文摘The exploration of ecological safety in tourism sites can provide a concrete path for sustainable tourism development in a region.Based on the“Driver-Pressure-State-Impact-Response”(DPSIR)model,we constructed an index system for the evaluation of tourism ecological security(TES)in the Silk Road Economic Belt(SREB)from 2005 to 2020.This index system was used to explore the characteristics of spatial and temporal dynamic evolution with the help of entropy weight TOPSIS method,dynamic index of TES and Markov probability transfer matrix,and a standard deviational ellipse(SDE)model and GM(1,1)model were constructed for spatial pattern analysis and prediction.The results indicate four key aspects of this system.(1)In terms of spatiotemporal evolution,the tourism ecological safety index(TESI)of the SREB increased,the TES levels of the northwestern and southwestern provinces and cities differed significantly,and the quality conditions of TES in the southwestern provinces and cities were better than in the northwest.(2)In terms of dynamic evolutionary characteristics,the speed of change at each level of the SREB was slow,but the level of TES has improved.The TES level has not shifted by leaps and bounds,and the shifts in the level type show“path dependence”and“self-locking”effects.(3)In terms of spatial and temporal distribution patterns,the spatial pattern of TES in the SREB is a“northwest-southeast”movement trend,and the spatial distribution appeared as“aggregation”from 2005 to 2020.The prediction results show that the center of gravity of TES in the SREB will shift to the southeast from 2025 to 2035,and the spatial spillover effect will be reduced.(4)In terms of driving factors,the number of star-rated hotels,and the amounts of industrial wastewater emissions,tourism foreign exchange earnings,forest coverage,and other parameters are the key factors affecting TES,and the booming tourism industry requires the interconnection and interpenetration of various factors.The results of this study can provide a reference for tourism development and ecological environmental protection in the Silk Road Economic Belt.
