The population of the intertidal gastropod Littorina saxcailis from Laxey estuary in the Isle of Man is exposed to mine-related contamination of Zn （and is tolerant to Zn and Pb） compared to those of Castletown, Der...The population of the intertidal gastropod Littorina saxcailis from Laxey estuary in the Isle of Man is exposed to mine-related contamination of Zn （and is tolerant to Zn and Pb） compared to those of Castletown, Derbyhaven, Peel and Ramsey. Tolerances to salinity and desiccation stress were assayed to test how metal tolerance could affect tolerance to general stress. The winkles were experimentally exposed to salinities of 0, 17 and 60 practical salinity units （psu） with 34 psu as control. Desiccation stress was determined by aerial exposure of the winkles at 24℃. No control mortalities were recorded and mortalities in 17 psu were less than 50% for all populations over a 24-day exposure period. LT50 values （mean±SD, n=5） at 0 psu ranged from 6.6 ± 0.6 to 7.5 ± 1.3 d for winkles from Ramsey and Laxey respectively. The values for 60 psu ranged from 7.0±0.7 to 8.4±0.9 d. No significant differences in LT50 values were obtained for the salinity exposurcs（ANOVA,P〉0.05） but there was a significant difference in tolerance to desiccation （P〈0.01）. The winkles from Laxey showed very high susceptibility to desiccation stress probably indicating a physiological trade-off to metal tolerance.展开更多
The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite network.DT-DVTR in the snapshot-based connectionoriented routing strategy is one o...The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite network.DT-DVTR in the snapshot-based connectionoriented routing strategy is one of the representative solutions,but it still has room for improvement in terms of routing stability.In this paper,we propose an improved scheme for connection-oriented routing strategy named the Minimal Topology Change Routing based on Collaborative Rules(MTCR-CR).The MTCR-CR uses continuous time static topology snapshots based on satellite status to search for intersatellite link(ISL)construction solutions that meet the minimum number of topology changes to avoid route oscillations.The simulation results in Beidou-3 show that compared with DT-DVTR,MTCR-CR reduces the number of routing changes by about 92%,the number of path changes caused by routing changes is about38%,and the rerouting time is reduced by approximately 47%.At the same time,in order to show our algorithm more comprehensively,the same experimental index test was also carried out on the Globalstar satellite constellation.展开更多
[目的/意义]展现一个学科与其他学科之间知识吸收和知识扩散的完整过程,揭示学科知识发展的来龙去脉。[方法/过程]利用国际权威引文数据库Web of Science,依据Web of Science学科类别划分标准,以Information Science&Library Scien...[目的/意义]展现一个学科与其他学科之间知识吸收和知识扩散的完整过程,揭示学科知识发展的来龙去脉。[方法/过程]利用国际权威引文数据库Web of Science,依据Web of Science学科类别划分标准,以Information Science&Library Science(以下简称ISLS)为例,选择2006-2010年和2011-2015年两个时间段,建立三个数据集(施引文献集、原始文献集、被引文献集),利用双图叠加可视化的方式探析ISLS与其他学科在期刊层面的知识吸收过程;利用知识扩散广度、强度和速度三个指标揭示ISLS与其他学科之间知识扩散现状和发展趋势。[结果/结论]在两个阶段内,ISLS主要吸收期刊类群心理、教育、社会的知识,知识来源学科主要为计算机科学学和管理学,在相应时间段内,知识扩散广度与时间呈对数函数关系,知识扩散速度与时间呈指数函数关系,ISLS向其他学科的知识扩散强度呈幂率分布。展开更多
为了实现视频和键盘鼠标信号远程传输,以微处理器、ISL59911和ISL59311芯片为核心,研制了一款低成本的KVM(Keyboard Video Mouse)信号双绞线远程传输系统。该系统包括发送模块和接收模块两个部分,分别完成对视频和键盘鼠标信号的发送和...为了实现视频和键盘鼠标信号远程传输,以微处理器、ISL59911和ISL59311芯片为核心,研制了一款低成本的KVM(Keyboard Video Mouse)信号双绞线远程传输系统。该系统包括发送模块和接收模块两个部分,分别完成对视频和键盘鼠标信号的发送和接收处理。经过实验验证,采用本设计的视频和键鼠信号传输距离可达200 m,广泛用于安防和工控领域。展开更多
基金TheCom m onwealthU niversitiesCom m issionintheU nitedK ingdom
文摘The population of the intertidal gastropod Littorina saxcailis from Laxey estuary in the Isle of Man is exposed to mine-related contamination of Zn （and is tolerant to Zn and Pb） compared to those of Castletown, Derbyhaven, Peel and Ramsey. Tolerances to salinity and desiccation stress were assayed to test how metal tolerance could affect tolerance to general stress. The winkles were experimentally exposed to salinities of 0, 17 and 60 practical salinity units （psu） with 34 psu as control. Desiccation stress was determined by aerial exposure of the winkles at 24℃. No control mortalities were recorded and mortalities in 17 psu were less than 50% for all populations over a 24-day exposure period. LT50 values （mean±SD, n=5） at 0 psu ranged from 6.6 ± 0.6 to 7.5 ± 1.3 d for winkles from Ramsey and Laxey respectively. The values for 60 psu ranged from 7.0±0.7 to 8.4±0.9 d. No significant differences in LT50 values were obtained for the salinity exposurcs（ANOVA,P〉0.05） but there was a significant difference in tolerance to desiccation （P〈0.01）. The winkles from Laxey showed very high susceptibility to desiccation stress probably indicating a physiological trade-off to metal tolerance.
基金supported by the National Key Research and Development Program of China(No.2020YFB1806000)。
文摘The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite network.DT-DVTR in the snapshot-based connectionoriented routing strategy is one of the representative solutions,but it still has room for improvement in terms of routing stability.In this paper,we propose an improved scheme for connection-oriented routing strategy named the Minimal Topology Change Routing based on Collaborative Rules(MTCR-CR).The MTCR-CR uses continuous time static topology snapshots based on satellite status to search for intersatellite link(ISL)construction solutions that meet the minimum number of topology changes to avoid route oscillations.The simulation results in Beidou-3 show that compared with DT-DVTR,MTCR-CR reduces the number of routing changes by about 92%,the number of path changes caused by routing changes is about38%,and the rerouting time is reduced by approximately 47%.At the same time,in order to show our algorithm more comprehensively,the same experimental index test was also carried out on the Globalstar satellite constellation.
文摘[目的/意义]展现一个学科与其他学科之间知识吸收和知识扩散的完整过程,揭示学科知识发展的来龙去脉。[方法/过程]利用国际权威引文数据库Web of Science,依据Web of Science学科类别划分标准,以Information Science&Library Science(以下简称ISLS)为例,选择2006-2010年和2011-2015年两个时间段,建立三个数据集(施引文献集、原始文献集、被引文献集),利用双图叠加可视化的方式探析ISLS与其他学科在期刊层面的知识吸收过程;利用知识扩散广度、强度和速度三个指标揭示ISLS与其他学科之间知识扩散现状和发展趋势。[结果/结论]在两个阶段内,ISLS主要吸收期刊类群心理、教育、社会的知识,知识来源学科主要为计算机科学学和管理学,在相应时间段内,知识扩散广度与时间呈对数函数关系,知识扩散速度与时间呈指数函数关系,ISLS向其他学科的知识扩散强度呈幂率分布。
文摘为了实现视频和键盘鼠标信号远程传输,以微处理器、ISL59911和ISL59311芯片为核心,研制了一款低成本的KVM(Keyboard Video Mouse)信号双绞线远程传输系统。该系统包括发送模块和接收模块两个部分,分别完成对视频和键盘鼠标信号的发送和接收处理。经过实验验证,采用本设计的视频和键鼠信号传输距离可达200 m,广泛用于安防和工控领域。
