Based on the background of the Nanchang Honggu Tunnel,which is the largest inland river immersed tunnel to date in China,some research work on the construction of the Nanchang Honggu Tunnel health monitoring and asses...Based on the background of the Nanchang Honggu Tunnel,which is the largest inland river immersed tunnel to date in China,some research work on the construction of the Nanchang Honggu Tunnel health monitoring and assessment system is introduced.The platform of the health monitoring and assessment system is established with a relatively mature structure,including the sensor subsystem,data acquisition subsystem,data transmission subsystem,database subsystem,data processing and control subsystem,and health assessment and pre-warning subsystem.Monitoring index selection,sensor selection and sensor layout are fully considered in the health monitoring design and technology scheme.The fuzzy-AHP(analytic hierarchy process)evaluation method is employed to establish the Honggu Tunnel health assessment model,and the index weight determination method and grading control criterion are investigated and given.Then,the functions of the software system are achieved with advanced cloud platform technology,and the running costs of the system is reduced greatly.In summary,the establishment of the Nanchang Honggu Tunnel health monitoring and assessment system is described and such a system can realize real-time monitoring of the Honggu Tunnel and make it more convenient for implementing health assessment,pre-warning,and some other functions.Managers can operate the system using PCs and cell phones.At the same time,the relevant work on this system can provide a good reference for other immersed tunnels.展开更多
全新世以来,全球增温、人类活动加剧,使得火演化规律和火机制愈加复杂。系统性地研究全新世火活动的时空演化规律,不仅可以更清晰地理解区域火活动机制与气候因子、植物特征以及人类活动之间的关联,而且对预测未来火的演化趋势具有现实...全新世以来,全球增温、人类活动加剧,使得火演化规律和火机制愈加复杂。系统性地研究全新世火活动的时空演化规律,不仅可以更清晰地理解区域火活动机制与气候因子、植物特征以及人类活动之间的关联,而且对预测未来火的演化趋势具有现实的指导意义。文章综合对比分析了中国中东部季风区域全新世以来的炭屑/黑碳沉积记录,发现该区域全新世火活动呈现出较大的时空差异。空间分布上,该区域火活动最活跃期从东北至东南呈现随纬度降低而趋晚的趋势,即东北地区早、中全新世,黄土高原和长江流域的中全新世(分别约为8.0~6.0 ka B.P.、6.0~4.5 ka B.P.),以及南部地区晚全新世(4.0~2.0 ka B.P.)火活动较强;时间序列上,该区域火活动在4.0 ka B.P.前后呈现明显不同的变化规律,其中中国南部地区、黄土高原及东北地区自约4.0 ka B.P.后火活动有明显增强;长江流域该时段前后火活动有所减弱,直至约2.2 ka B.P.前后火活动有所回升。综合分析认为,在中早全新世,不同地区火活动最活跃期主要受控于水热配置影响,但生物量和局域人类活动因素不可忽略;在晚全新世约4.0 ka B.P.前后长江流域火活动因先民伐林活动导致植被覆盖下降而有所抑制,而其他地区约4.0 ka B.P.以来的人类活动对于当地火事件具有增强的影响。此外,通过综合不同沉积环境的炭屑/黑碳记录来反演火历史规律,需要考虑燃料来源、搬运沉积过程以及研究方法差异性的影响。不仅如此,有效区分人为火活动和自然火活动是预测未来增温背景下火活动变化和控制因素的一个亟需解决的科学难题。展开更多
基金The National Natural Science Foundation of China(No.51878157)
文摘Based on the background of the Nanchang Honggu Tunnel,which is the largest inland river immersed tunnel to date in China,some research work on the construction of the Nanchang Honggu Tunnel health monitoring and assessment system is introduced.The platform of the health monitoring and assessment system is established with a relatively mature structure,including the sensor subsystem,data acquisition subsystem,data transmission subsystem,database subsystem,data processing and control subsystem,and health assessment and pre-warning subsystem.Monitoring index selection,sensor selection and sensor layout are fully considered in the health monitoring design and technology scheme.The fuzzy-AHP(analytic hierarchy process)evaluation method is employed to establish the Honggu Tunnel health assessment model,and the index weight determination method and grading control criterion are investigated and given.Then,the functions of the software system are achieved with advanced cloud platform technology,and the running costs of the system is reduced greatly.In summary,the establishment of the Nanchang Honggu Tunnel health monitoring and assessment system is described and such a system can realize real-time monitoring of the Honggu Tunnel and make it more convenient for implementing health assessment,pre-warning,and some other functions.Managers can operate the system using PCs and cell phones.At the same time,the relevant work on this system can provide a good reference for other immersed tunnels.
文摘全新世以来,全球增温、人类活动加剧,使得火演化规律和火机制愈加复杂。系统性地研究全新世火活动的时空演化规律,不仅可以更清晰地理解区域火活动机制与气候因子、植物特征以及人类活动之间的关联,而且对预测未来火的演化趋势具有现实的指导意义。文章综合对比分析了中国中东部季风区域全新世以来的炭屑/黑碳沉积记录,发现该区域全新世火活动呈现出较大的时空差异。空间分布上,该区域火活动最活跃期从东北至东南呈现随纬度降低而趋晚的趋势,即东北地区早、中全新世,黄土高原和长江流域的中全新世(分别约为8.0~6.0 ka B.P.、6.0~4.5 ka B.P.),以及南部地区晚全新世(4.0~2.0 ka B.P.)火活动较强;时间序列上,该区域火活动在4.0 ka B.P.前后呈现明显不同的变化规律,其中中国南部地区、黄土高原及东北地区自约4.0 ka B.P.后火活动有明显增强;长江流域该时段前后火活动有所减弱,直至约2.2 ka B.P.前后火活动有所回升。综合分析认为,在中早全新世,不同地区火活动最活跃期主要受控于水热配置影响,但生物量和局域人类活动因素不可忽略;在晚全新世约4.0 ka B.P.前后长江流域火活动因先民伐林活动导致植被覆盖下降而有所抑制,而其他地区约4.0 ka B.P.以来的人类活动对于当地火事件具有增强的影响。此外,通过综合不同沉积环境的炭屑/黑碳记录来反演火历史规律,需要考虑燃料来源、搬运沉积过程以及研究方法差异性的影响。不仅如此,有效区分人为火活动和自然火活动是预测未来增温背景下火活动变化和控制因素的一个亟需解决的科学难题。
