With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation wind...With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation window period is crucial for navigating in the Arctic route,which is of great significance to the selection of the route and the optimization of navigation.This paper introduces the establishment of a risk index system,determination of risk index weight,establishment of a risk evaluation model,and prediction algorithm for the window period.In addition,data sources of both environmental factors and ship factors are introducted,and their shortcomings are analyzed,followed by introduction of various methods involved in window prediction and analysis of their advantages and disadvantages.The quantitative risk evaluation and window period algorithm can provide a reference for the research of polar navigation window period prediction.展开更多
Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the ...Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.展开更多
航空光电装备平面光学窗口在确定构型尺寸和组合形式后,窗口厚度对装备成像性能影响至为关键。从设计变量、组合形式、作用载荷3个方面对窗口设计问题进行分析,确定了基于结构刚性和RMS(root mean square)波前误差的平面窗口厚度设计目...航空光电装备平面光学窗口在确定构型尺寸和组合形式后,窗口厚度对装备成像性能影响至为关键。从设计变量、组合形式、作用载荷3个方面对窗口设计问题进行分析,确定了基于结构刚性和RMS(root mean square)波前误差的平面窗口厚度设计目标;从光学窗口一阶结构谐振频率及其在温度和压力载荷作用下的RMS波前误差量化求解出窗口厚度尺寸范围11.9 mm~18.4 mm;提出针对光学窗口组合工况性能计算的集成分析流程,计算得到光学窗口一阶谐振频率为151 Hz,在飞行工作时各向组合工况-流场/重力/振动作用下光学窗口RMS波前误差不大于1/10参考波长。实验测试结果表明:光学窗口RMS波前误差小于0.07参考波长,实物样机振动和飞行条件下成像清晰、稳定,证明窗口厚度尺寸设计分析方法正确有效。展开更多
在经典车辆路径问题(vehicle routing problem,VRP)的基础上增加了客户要求访问的时间窗约束,以车辆行驶路径最短和使用车辆数最小为目标,建立了不确定车辆数的多约束车辆路径问题(multi-constraint vehicle routing problem with varia...在经典车辆路径问题(vehicle routing problem,VRP)的基础上增加了客户要求访问的时间窗约束,以车辆行驶路径最短和使用车辆数最小为目标,建立了不确定车辆数的多约束车辆路径问题(multi-constraint vehicle routing problem with variable fleets,MVRP-VF)的数学模型。引入遗传算法的交叉操作以及大规模邻域搜索算法中的破坏算子和修复算子,重新定义了基本灰狼优化算法(grey wolf optimizer,GWO)的操作算子,优化了GWO的寻优机制,从而设计出用于求解MVRP-VF问题的混合灰狼优化算法(hybrid grey wolf optimizer,HGWO)。通过仿真实验与其他参考文献中的算法求解结果进行比较,验证了HGWO求解该类问题的有效性与可行性。展开更多
文摘With the increase of international trade activities and the gradual melting of the polar ice cap,the importance of the Arctic route for marine transportation has been emphasized.Prediction of the polar navigation window period is crucial for navigating in the Arctic route,which is of great significance to the selection of the route and the optimization of navigation.This paper introduces the establishment of a risk index system,determination of risk index weight,establishment of a risk evaluation model,and prediction algorithm for the window period.In addition,data sources of both environmental factors and ship factors are introducted,and their shortcomings are analyzed,followed by introduction of various methods involved in window prediction and analysis of their advantages and disadvantages.The quantitative risk evaluation and window period algorithm can provide a reference for the research of polar navigation window period prediction.
基金supported by the Longkou City Science and Technology Research and Development Plan(No.2020KJJH061).
文摘Developing supercapacitors(SCs)with long cycling life and wide operative voltage window is a significant topic in the field of aqueous electrolytes.Although the design of water in salt(WIS)electrolytes has pushed the development of aqueous electrolytes to a new height,the WIS electrolytes with an operative voltage window of up to 2.5 V is still very scarce.Herein,in order to enrich the type of aqueous electrolyte with high operative voltage,tetramethylammonium trifluoromethanesulfonate(TMAOTf)based WIS electrolyte was used as a model to construct WIS based hybrid electrolyte with acetonitrile(ACN)co-solvent and LiTFSI co-solute.In view of the coordination effect of ACN and Lit on free water in TMAOTf based WIS electrolyte,the TMAt-Lit-AWIS electrolyte has the electrochemical stabilization window of up to 3.35 V.Further coupled with the commercial YP-50F electrodes,TMAt-Lit-AWIS based SCs exhibited wide operative voltage window(2.5 V),long cycling life(45,000 cycles)and good low-temperature performance(99.99%capacitance retention after 2000 cycles at20℃).The design of this hybrid electrolyte will enrich the types of aqueous hybrid electrolytes with long cycling life and wide operative voltage window.
文摘在经典车辆路径问题(vehicle routing problem,VRP)的基础上增加了客户要求访问的时间窗约束,以车辆行驶路径最短和使用车辆数最小为目标,建立了不确定车辆数的多约束车辆路径问题(multi-constraint vehicle routing problem with variable fleets,MVRP-VF)的数学模型。引入遗传算法的交叉操作以及大规模邻域搜索算法中的破坏算子和修复算子,重新定义了基本灰狼优化算法(grey wolf optimizer,GWO)的操作算子,优化了GWO的寻优机制,从而设计出用于求解MVRP-VF问题的混合灰狼优化算法(hybrid grey wolf optimizer,HGWO)。通过仿真实验与其他参考文献中的算法求解结果进行比较,验证了HGWO求解该类问题的有效性与可行性。
