Debris flow hazards seriously threaten thesafety and sustainable development of mountainousareas. Numerous debris flow mitigation measures havebeen implemented worldwide;however, acomprehensive assessment of the speci...Debris flow hazards seriously threaten thesafety and sustainable development of mountainousareas. Numerous debris flow mitigation measures havebeen implemented worldwide;however, acomprehensive assessment of the specific disasterreduction effects of these measures and their economic,social and ecological benefits is yet to be performed.The western region of Sichuan Province frequentlysuffers from geohazards such as debris flow, and thegovernment has adopted many mitigation measures.This study assessed the benefits of debris flowmitigation measures and identified the key influencingfactors via a field-based study conducted in 81 villagesin western Sichuan province, China. A framework forthe evaluation of the benefits of rural debris flowmitigation measures was constructed andquantitatively evaluated using a survey. Snowballsampling was performed to recruit 81 village leadersand 468 farmers. The results showed that managementand engineering measures were the main methodsused to mitigate debris flow;ecological measures wereauxiliary. The average satisfaction scores of farmers forthese three types of measures were 4.07, 3.90, and 3.56,respectively (as measured on a five-point Likert scale).In contrast, in terms of the benefits of these mitigationmeasures, only a small proportion of villages (11.11%)obtained a high level of comprehensive benefits fromthe debris flow mitigation measures, while the majority(88.89%) received medium to low-level benefits. Toimprove this situation, we further studied and foundthat the main factors that restricted villages fromachieving high-level comprehensive benefits were theunpredictable nature of debris flows, labour forceoutflow and remoteness. Effective control measures, agood economic environment and strong governmentassistance were reported as crucial factors forimproving these comprehensive benefits. This studyprovides socio-scientific references for decisionmakingon rural debris flow mitigation measures while keeping villages at the centre of economic development.展开更多
It is of great significance to carry out effective scheduling for the carrier-based aircraft flight deck operations.In this paper,the precedence constraints and resource constraints in flight deck operations are analy...It is of great significance to carry out effective scheduling for the carrier-based aircraft flight deck operations.In this paper,the precedence constraints and resource constraints in flight deck operations are analyzed,then the model of the multi-aircraft integrated scheduling problem with transfer times(MAISPTT)is established.A dual population multi-operator genetic algorithm(DPMOGA)is proposed for solving the problem.In the algorithm,the dual population structure and random-key encoding modified by starting/ending time of operations are adopted,and multiple genetic operators are self-adaptively used to obtain better encodings.In order to conduct the mapping from encodings to feasible schedules,serial and parallel scheduling generation scheme-based decoding operators,each of which adopts different justified mechanisms in two separated populations,are introduced.The superiority of the DPMOGA is verified by simulation experiments.展开更多
电池储能是碳中和目标的有力抓手,准确估计其能量状态(state of energy,SOE)和峰值功率状态(state of power,SOP)是电池储能高效可靠运行的关键和基础。由于电池的电化学反应过程十分复杂,作为隐性状态量的SOE和SOP精确值难以获得。为此...电池储能是碳中和目标的有力抓手,准确估计其能量状态(state of energy,SOE)和峰值功率状态(state of power,SOP)是电池储能高效可靠运行的关键和基础。由于电池的电化学反应过程十分复杂,作为隐性状态量的SOE和SOP精确值难以获得。为此,本工作提出了一种基于模型SOE和SOP联合估计方法。应用Thevenin等效电路模型,采用递归最小二乘法建立了在线参数辨识算法,获得准确的模型参数。为解决恒定功率需求下的功率预测难题,提出了多步功率预测法,提高了SOP的预测精度,并结合扩展卡尔曼滤波算法,进一步提出了多状态联合估计方法。实验验证了算法的可行性,结果表明,在存在较大初始误差的情况下,所提出的方法电压、SOE最大预测误差均<2%,实现了准确的SOP预测。展开更多
为了解决单一水合盐相变材料过冷度大、热导率小、循环稳定性差等问题,以十二水硫酸铝铵为相变材料,采用熔融共混法将Al2O3与黄原胶作为添加剂对十二水硫酸铝铵进行改性,采用多孔吸附法将改性膨胀石墨和改性十二水硫酸铝铵复合,制备了...为了解决单一水合盐相变材料过冷度大、热导率小、循环稳定性差等问题,以十二水硫酸铝铵为相变材料,采用熔融共混法将Al2O3与黄原胶作为添加剂对十二水硫酸铝铵进行改性,采用多孔吸附法将改性膨胀石墨和改性十二水硫酸铝铵复合,制备了一种新型复合相变材料,并研究了其热物性、过冷度、循环稳定性和材料相容性。实验结果表明:复合相变材料的熔点、潜热和导热系数分别为93.23℃、235.40 k J/kg和4.086 W/(m·K);循环50次后,过冷度稳定在24.00℃,且循环300次后,潜热仅下降5.9%,具有较好稳定性;316L不锈钢和复合相变材料具有较好的相容性,可作为封装容器材料使用。该复合相变材料具有良好的性能,在建筑物供暖方面具有较大的应用潜力。展开更多
基金supported by the Science and Technology Research Program of the Institute of Mountain Hazards and Environment,Chinese Academy of Sciences(Grant No.IMHE-ZDRW-08)the Sichuan Science and Technology Program(Grant No.2022JDR0209).
文摘Debris flow hazards seriously threaten thesafety and sustainable development of mountainousareas. Numerous debris flow mitigation measures havebeen implemented worldwide;however, acomprehensive assessment of the specific disasterreduction effects of these measures and their economic,social and ecological benefits is yet to be performed.The western region of Sichuan Province frequentlysuffers from geohazards such as debris flow, and thegovernment has adopted many mitigation measures.This study assessed the benefits of debris flowmitigation measures and identified the key influencingfactors via a field-based study conducted in 81 villagesin western Sichuan province, China. A framework forthe evaluation of the benefits of rural debris flowmitigation measures was constructed andquantitatively evaluated using a survey. Snowballsampling was performed to recruit 81 village leadersand 468 farmers. The results showed that managementand engineering measures were the main methodsused to mitigate debris flow;ecological measures wereauxiliary. The average satisfaction scores of farmers forthese three types of measures were 4.07, 3.90, and 3.56,respectively (as measured on a five-point Likert scale).In contrast, in terms of the benefits of these mitigationmeasures, only a small proportion of villages (11.11%)obtained a high level of comprehensive benefits fromthe debris flow mitigation measures, while the majority(88.89%) received medium to low-level benefits. Toimprove this situation, we further studied and foundthat the main factors that restricted villages fromachieving high-level comprehensive benefits were theunpredictable nature of debris flows, labour forceoutflow and remoteness. Effective control measures, agood economic environment and strong governmentassistance were reported as crucial factors forimproving these comprehensive benefits. This studyprovides socio-scientific references for decisionmakingon rural debris flow mitigation measures while keeping villages at the centre of economic development.
基金supported by the National Natural Science Foundation of China(61671462).
文摘It is of great significance to carry out effective scheduling for the carrier-based aircraft flight deck operations.In this paper,the precedence constraints and resource constraints in flight deck operations are analyzed,then the model of the multi-aircraft integrated scheduling problem with transfer times(MAISPTT)is established.A dual population multi-operator genetic algorithm(DPMOGA)is proposed for solving the problem.In the algorithm,the dual population structure and random-key encoding modified by starting/ending time of operations are adopted,and multiple genetic operators are self-adaptively used to obtain better encodings.In order to conduct the mapping from encodings to feasible schedules,serial and parallel scheduling generation scheme-based decoding operators,each of which adopts different justified mechanisms in two separated populations,are introduced.The superiority of the DPMOGA is verified by simulation experiments.
文摘电池储能是碳中和目标的有力抓手,准确估计其能量状态(state of energy,SOE)和峰值功率状态(state of power,SOP)是电池储能高效可靠运行的关键和基础。由于电池的电化学反应过程十分复杂,作为隐性状态量的SOE和SOP精确值难以获得。为此,本工作提出了一种基于模型SOE和SOP联合估计方法。应用Thevenin等效电路模型,采用递归最小二乘法建立了在线参数辨识算法,获得准确的模型参数。为解决恒定功率需求下的功率预测难题,提出了多步功率预测法,提高了SOP的预测精度,并结合扩展卡尔曼滤波算法,进一步提出了多状态联合估计方法。实验验证了算法的可行性,结果表明,在存在较大初始误差的情况下,所提出的方法电压、SOE最大预测误差均<2%,实现了准确的SOP预测。
文摘为了解决单一水合盐相变材料过冷度大、热导率小、循环稳定性差等问题,以十二水硫酸铝铵为相变材料,采用熔融共混法将Al2O3与黄原胶作为添加剂对十二水硫酸铝铵进行改性,采用多孔吸附法将改性膨胀石墨和改性十二水硫酸铝铵复合,制备了一种新型复合相变材料,并研究了其热物性、过冷度、循环稳定性和材料相容性。实验结果表明:复合相变材料的熔点、潜热和导热系数分别为93.23℃、235.40 k J/kg和4.086 W/(m·K);循环50次后,过冷度稳定在24.00℃,且循环300次后,潜热仅下降5.9%,具有较好稳定性;316L不锈钢和复合相变材料具有较好的相容性,可作为封装容器材料使用。该复合相变材料具有良好的性能,在建筑物供暖方面具有较大的应用潜力。
文摘射频电路优化设计是保证射频通信系统高可靠、低功耗、远距离数据传输的重要手段。针对商用CC1101射频电路传输距离短和丢包率高的问题,通过高频电磁仿真软件ADS(Advanced Design System)对CC1101射频电路中阻抗变换器、滤波器和射频全链路进行仿真优化,根据仿真结果调整元器件,并测试了改版CC1101射频电路的传输距离和数据包接收率。结果表明,优化后射频电路阻抗(115+j42Ω)更接近目标差分阻抗(116+j41Ω),回波损耗提高11 d B,插入损耗减少0.6 d B,稳定传输距离提升30 m,在传输距离为60 m时数据接收率提高33.6%。
