As unmanned aerial vehicles(UAVs) are used more and more in military operations, increasing their level of autonomous decision making becomes necessary. In uncertain battlefield environments, when making sovereign dec...As unmanned aerial vehicles(UAVs) are used more and more in military operations, increasing their level of autonomous decision making becomes necessary. In uncertain battlefield environments, when making sovereign decisions, UAVs must choose low-risk options. An integrated framework is proposed for UAV robust decision making in air-to-ground attack missions under severe uncertainty. In the offline part of the framework, the battlefield scenarios are analyzed and an influence diagram is built to represent the decision situation. In the online part, the UAV evaluates the alternative actions for every scenario, and then the optimal robust action is chosen, using the robust decision model. Results of simulation show that the proposed approach is feasible and effective. The framework can support UAVs in making independent robust decisions under circumstances which require immediate responses under severe uncertainty, and it can also be extended to applications in more complex situations.展开更多
Objective:To investigate the effect of salvia miltiorrhiza on expression of the MMP-2、9 and TIMP-1、TIMP-2 in tissue of acute lung injury of severe acute pancreatitis(SAP).Methods:MMP-2、9 expression and changes of t...Objective:To investigate the effect of salvia miltiorrhiza on expression of the MMP-2、9 and TIMP-1、TIMP-2 in tissue of acute lung injury of severe acute pancreatitis(SAP).Methods:MMP-2、9 expression and changes of the lung were measured after the SAP rats were induced by retrograde injection of 5%sodium tauocholate into hepatopancreatic duct.The changes of those parameters were also measured after salvia miltiorrhiza was injected intramuscularly just after induction of SAP.Results:The level of MMP-2、9 in pancreas and lung in SAP group were significantly higher than those in sham;The level of MMP-2、9 in salvia miltiorrhiza group were significantly lower than those in SAP group. Conclusion:MMP-2、9 were overexpressed in Acute lung injury (ALI) induced by SAP, salvia miltiorrhiza downregulates MMP-2、9 expression and decreased injury of lung tissue.展开更多
RDX/Al mixtures are widely utilized in energetic materials,yet their hybrid dust generated during production and application poses potential explosion hazards.Moreover,the synergistic explosion mechanisms remain poorl...RDX/Al mixtures are widely utilized in energetic materials,yet their hybrid dust generated during production and application poses potential explosion hazards.Moreover,the synergistic explosion mechanisms remain poorly understood,particularly at varying dust concentrations.This study systematically investigates the effects of different aluminum powder mass percentages and dust concentrations(300 g/m^(3),600 g/m^(3),900 g/m^(3))on RDX dust explosion severity,flame propagation behavior,and gaseous products.The results indicate that the maximum explosion pressure peaks at 35%RDX,65%RDX,and 80%RDX at 300 g/m^(3),600 g/m^(3),and 900 g/m^(3),respectively.Concurrently,the time for the flame to propagate to the wall(t1)reaches minimum values of 34.8 ms,25.66 ms,and 23.93 ms.The maximum rate of pressure rise is observed for pure RDX at 900 g/m^(3).Aluminum powder enhances flame propagation velocity and combustion duration,as validated by the flame propagation system.Overall,the concentrations of carbon oxides(CO+CO_(2))decrease significantly with increasing aluminum mass percentage.At 20%RDX,the concentrations decreased by 51.64%,72.31%,and 79.55%compared to pure RDX at 300 g/m^(3),600 g/m^(3),and 900 g/m^(3),respectively.Notably,N_(2)O concentration only at 300 g/m^(3)showed such a trend.It rises first and then falls at 35%RDX at 600 g/m^(3)and 900 g/m^(3).These findings elucidate the synergistic explosion mechanisms and provide critical guidelines for safe production and handling.展开更多
讨论了基于SQL Sever 2000数据库、B/S模型构建的矿山安全生产信息系统的开发,该系统采用自顶而下、不断迭代和优化的开发策略,能够实时、动态存储和管理安全、生产等信息,并使得这些信息实现共享,提高生产、安全和质量管理的决策科学...讨论了基于SQL Sever 2000数据库、B/S模型构建的矿山安全生产信息系统的开发,该系统采用自顶而下、不断迭代和优化的开发策略,能够实时、动态存储和管理安全、生产等信息,并使得这些信息实现共享,提高生产、安全和质量管理的决策科学性与实时处理问题的能力。展开更多
介绍了一个基于client/sever结构,前端应用程序使用DELPHI 5.0作为开发工具,后台使用Microsoft SQL SERVER 7.0作为数据库支持的教师评测软件系统的设计与实现方法。通过对教师自评、专家评价和学生评价的评价数据采集、模糊评测分析...介绍了一个基于client/sever结构,前端应用程序使用DELPHI 5.0作为开发工具,后台使用Microsoft SQL SERVER 7.0作为数据库支持的教师评测软件系统的设计与实现方法。通过对教师自评、专家评价和学生评价的评价数据采集、模糊评测分析和统计,实现了对教师教学工作的全面、准确、科学的评价,同时该系统还具备教师信息查询、打印、数据库维护等功能,实现教师信息管理的无纸化办公。展开更多
基金Projects(7113100271401048)supported by the National Natural Science Foundation of China+1 种基金Project(13YJC630051)supported by the Humanities and Social Science Program of Ministry of Education of ChinaProject(2012HGZY0009)supported by the Fundamental Research Funds for the Central Universities of China
文摘As unmanned aerial vehicles(UAVs) are used more and more in military operations, increasing their level of autonomous decision making becomes necessary. In uncertain battlefield environments, when making sovereign decisions, UAVs must choose low-risk options. An integrated framework is proposed for UAV robust decision making in air-to-ground attack missions under severe uncertainty. In the offline part of the framework, the battlefield scenarios are analyzed and an influence diagram is built to represent the decision situation. In the online part, the UAV evaluates the alternative actions for every scenario, and then the optimal robust action is chosen, using the robust decision model. Results of simulation show that the proposed approach is feasible and effective. The framework can support UAVs in making independent robust decisions under circumstances which require immediate responses under severe uncertainty, and it can also be extended to applications in more complex situations.
基金supported mainly by Chinese traditionalmedicines and drugs administrative agent(92B093)
文摘Objective:To investigate the effect of salvia miltiorrhiza on expression of the MMP-2、9 and TIMP-1、TIMP-2 in tissue of acute lung injury of severe acute pancreatitis(SAP).Methods:MMP-2、9 expression and changes of the lung were measured after the SAP rats were induced by retrograde injection of 5%sodium tauocholate into hepatopancreatic duct.The changes of those parameters were also measured after salvia miltiorrhiza was injected intramuscularly just after induction of SAP.Results:The level of MMP-2、9 in pancreas and lung in SAP group were significantly higher than those in sham;The level of MMP-2、9 in salvia miltiorrhiza group were significantly lower than those in SAP group. Conclusion:MMP-2、9 were overexpressed in Acute lung injury (ALI) induced by SAP, salvia miltiorrhiza downregulates MMP-2、9 expression and decreased injury of lung tissue.
基金the financial support of the Shanxi Fire&Explosion-Proofing Safety Engineering and Technology Research Center,North University of China。
文摘RDX/Al mixtures are widely utilized in energetic materials,yet their hybrid dust generated during production and application poses potential explosion hazards.Moreover,the synergistic explosion mechanisms remain poorly understood,particularly at varying dust concentrations.This study systematically investigates the effects of different aluminum powder mass percentages and dust concentrations(300 g/m^(3),600 g/m^(3),900 g/m^(3))on RDX dust explosion severity,flame propagation behavior,and gaseous products.The results indicate that the maximum explosion pressure peaks at 35%RDX,65%RDX,and 80%RDX at 300 g/m^(3),600 g/m^(3),and 900 g/m^(3),respectively.Concurrently,the time for the flame to propagate to the wall(t1)reaches minimum values of 34.8 ms,25.66 ms,and 23.93 ms.The maximum rate of pressure rise is observed for pure RDX at 900 g/m^(3).Aluminum powder enhances flame propagation velocity and combustion duration,as validated by the flame propagation system.Overall,the concentrations of carbon oxides(CO+CO_(2))decrease significantly with increasing aluminum mass percentage.At 20%RDX,the concentrations decreased by 51.64%,72.31%,and 79.55%compared to pure RDX at 300 g/m^(3),600 g/m^(3),and 900 g/m^(3),respectively.Notably,N_(2)O concentration only at 300 g/m^(3)showed such a trend.It rises first and then falls at 35%RDX at 600 g/m^(3)and 900 g/m^(3).These findings elucidate the synergistic explosion mechanisms and provide critical guidelines for safe production and handling.
文摘介绍了一个基于client/sever结构,前端应用程序使用DELPHI 5.0作为开发工具,后台使用Microsoft SQL SERVER 7.0作为数据库支持的教师评测软件系统的设计与实现方法。通过对教师自评、专家评价和学生评价的评价数据采集、模糊评测分析和统计,实现了对教师教学工作的全面、准确、科学的评价,同时该系统还具备教师信息查询、打印、数据库维护等功能,实现教师信息管理的无纸化办公。
