Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extens...Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extensive attention due to their advantages of small size,high multiplexing efficiency,convenient mass production,and low cost.An RGB beam combiner based on directional couplers is designed,with a core-cladding relative refractive index difference of 0.75%.The RGB beam combiner is optimized from the perspective of parameter optimization.Using the beam propagation method(BPM),the relationship between the performance of the RGB beam combiner and individual parameters is studied,achieving preliminary optimization of the device’s performance.The key parameters of the RGB beam combiner are optimized using the entropy weight-technique for order preference by similarity to an ideal solution TOPSIS method,establishing the optimal parameter scheme and further improving the device’s performance indicators.The results show that after optimization,the multiplexing efficiencies for red,green,and blue lights,as well as the average multiplexing efficiency,reached 99.17%,99.76%,96.63%and 98.52%,respectively.The size of the RGB beam combiner is 4.768 mm×0.062 mm.展开更多
In this paper, a 3rd order combination method with three processes and a 4th order combination method with five processes for solving ODEs are discussed. These methods are the Runge-Kutta method combined with a linear...In this paper, a 3rd order combination method with three processes and a 4th order combination method with five processes for solving ODEs are discussed. These methods are the Runge-Kutta method combined with a linear multistep method, which overcomes the defect of the 3rd order parallel Runge-Kutta method discussed in [1].展开更多
In this paper, a class of real-time parallel combined methods (RTPCM) of the digital simulation for a partitioned large system is presented. By means of combination of the parallelism across the system with the parall...In this paper, a class of real-time parallel combined methods (RTPCM) of the digital simulation for a partitioned large system is presented. By means of combination of the parallelism across the system with the parallelism across the method, stiff and non-stiff subsystems are solved in parallel on parallel computer by a parallel Rosenbrock method and a parallel RK method, respectively. Their construction, convergence and numerical stability are discussed, and the digitalsimulation experiments are conducted.展开更多
A class of modified parallel combined methods of real-time numerical simulation are presented for a stiff dynamic system. By combining the parallelism across the system with the parallelism across the method, and rela...A class of modified parallel combined methods of real-time numerical simulation are presented for a stiff dynamic system. By combining the parallelism across the system with the parallelism across the method, and relaxing the dependence of stage value computation on sampling time of input function, a class of modified real-time parallel combined methods are constructed. Stiff and nonstiff subsystems are solved in parallel on a parallel computer by a parallel Rosen-brock method and a parallel RK method, respectively. Their order conditions and convergences are discussed. The numerical simulation experiments show that this class of modified algorithms can get high speed and efficiency.展开更多
For a nonlinear limit state function, the first-order reliability method(FORM) may cause large errors in the computation of not only the reliability index or failure probability but also the reliability sensitivity. I...For a nonlinear limit state function, the first-order reliability method(FORM) may cause large errors in the computation of not only the reliability index or failure probability but also the reliability sensitivity. In order to obtain more the accurate results of the reliability sensitivity analysis, a number of hyperplanes are built near the design point by first-order Tayler series expansion, which replace the known nonlinear limit state hypersurface, and an equivalent computational method is utilized to construct an equivalent hyperplane of the obtained hyperplanes. And the reliability sensitivities can be estimated more accurately by the derived equations based on the equivalent hyperplane. An example shows that the method is effective and feasible.展开更多
This study designs four types of liquid-filled cylindrical shell structures to investigate their protection characteristics against explosive shock waves and high-speed fragments.Bare charge and charge-driven prefabri...This study designs four types of liquid-filled cylindrical shell structures to investigate their protection characteristics against explosive shock waves and high-speed fragments.Bare charge and charge-driven prefabricated fragments are employed to examine the damage under blast shock waves and combined blast and fragments loading on various liquid-filled cylindrical shell structures.The test results are compared to numerical calculations and theoretical analysis for the structure's deformation,the liquid medium's movement,and the pressure waves'propagation characteristics under different liquid-filling methods.The results showed that the filling method influences the blast protection and the struc-ture's energy absorption performance.The external filling method reduces the structural deformation,and the internal filling method increases the damage effect.The gapped internal filling method improves the structure's energy absorption efficiency.The pressure wave loading on the liquid-filled cylindrical shell structure differs depending on filling methods.Explosive shock waves and high-speed fragments show a damage enhancement effect on the liquid-filled cylindrical shell structure,depending on the thickness of the internal liquid container layer.The specific impulse on the inner surface of the cylindrical shell positively correlates to the radial deformation of the cylindrical shell structure,and the external liquid layer limits the radial structural deformation.展开更多
A novel control method for a general class of nonlinear systems using fuzzy logic systems （FLSs） is presertted. Indirect and direct methods are combined to design the adaptive fuzzy output feedback controller and a ...A novel control method for a general class of nonlinear systems using fuzzy logic systems （FLSs） is presertted. Indirect and direct methods are combined to design the adaptive fuzzy output feedback controller and a high-gain observer is used to estimate the derivatives of the system output. The closed-loop system is proven to be semiglobally uniformly ultimately bounded. In addition, it is shown that if the approximation accuracy of the fuzzy logic system is high enough and the observer gain is chosen sufficiently large, an arbitrarily small tracking error can be achieved. Simulation results verify the effectiveness of the newly designed scheme and the theoretical discussion.展开更多
适应城市化进程加速与气候变化,提高抵御洪涝灾害的能力是可持续发展的必由之路。从韧性视角出发,构建基于“自然-经济-社会-基础设施”的洪涝韧性评估框架,运用组合赋权-逼近理想解排序模型(Technique for Order Preference by Similar...适应城市化进程加速与气候变化,提高抵御洪涝灾害的能力是可持续发展的必由之路。从韧性视角出发,构建基于“自然-经济-社会-基础设施”的洪涝韧性评估框架,运用组合赋权-逼近理想解排序模型(Technique for Order Preference by Similarity to the Ideal Solution,TOPSIS)评估2007—2022年南京都市圈城市洪涝韧性水平,并利用障碍度模型诊断抑制洪涝韧性提升的主要因素。结果表明:(1)都市圈城市洪涝韧性呈上升趋势,从较低水平转变为中等水平;(2)洪涝韧性空间分布呈现以南京为核心、向四周辐射递减的“中心-外围”特征;(3)研究时段末南京都市圈洪涝韧性的关键限制因素有河流调蓄能力、人口脆弱度、政府财政情况,植被覆盖率为部分城市潜在障碍因素。研究可为南京都市圈完善洪涝灾害防治体系、提升洪涝韧性提供参考。展开更多
为建立一种可同时检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法,试验采用正己烷去脂,联合QuEChERS净化结合冷冻脂质过滤法,建立检测鸽蛋中5类24种兽药残留的高效液相色谱-串联质谱法。样品中的5类兽药(氯霉素类、磺胺类、硝基咪...为建立一种可同时检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法,试验采用正己烷去脂,联合QuEChERS净化结合冷冻脂质过滤法,建立检测鸽蛋中5类24种兽药残留的高效液相色谱-串联质谱法。样品中的5类兽药(氯霉素类、磺胺类、硝基咪唑类、喹诺酮类和抗病毒类)经1.0%乙酸乙腈溶液提取,氮气吹干,冷冻过夜后,结合QuEChERS净化和正己烷去脂,采用1 mL 0.1%甲酸水-乙腈溶液(v/v,90∶10)复溶;高效液相色谱-串联质谱测定,内标法定量,采用实际样品建立方法的初步应用。结果显示:24种兽药在2.0~200 ng/mL线性关系良好(R2>0.99),该方法的定量限为2μg/kg,平均回收率为62.2%~117.1%,相对标准偏差4.3%~18.9%;实际样品检出的7种目标化合物与标准方法相比的相对标准偏差为1.34%~5.20%。研究表明,建立的检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法省去固相萃取步骤,成本较低,灵敏高效,回收率优良、重复性稳定,适用于鸽蛋中多类兽药的快速监测分析。展开更多
基金Project(52175445)supported by the National Natural Science Foundation of ChinaProject(2022JJ30743)supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(2023GK2024)supported by the Key Research and Development Program of Hunan Province,ChinaProject(2023ZZTS0391)supported by the Fundamental Research Funds for the Central Universities of China。
文摘Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extensive attention due to their advantages of small size,high multiplexing efficiency,convenient mass production,and low cost.An RGB beam combiner based on directional couplers is designed,with a core-cladding relative refractive index difference of 0.75%.The RGB beam combiner is optimized from the perspective of parameter optimization.Using the beam propagation method(BPM),the relationship between the performance of the RGB beam combiner and individual parameters is studied,achieving preliminary optimization of the device’s performance.The key parameters of the RGB beam combiner are optimized using the entropy weight-technique for order preference by similarity to an ideal solution TOPSIS method,establishing the optimal parameter scheme and further improving the device’s performance indicators.The results show that after optimization,the multiplexing efficiencies for red,green,and blue lights,as well as the average multiplexing efficiency,reached 99.17%,99.76%,96.63%and 98.52%,respectively.The size of the RGB beam combiner is 4.768 mm×0.062 mm.
文摘In this paper, a 3rd order combination method with three processes and a 4th order combination method with five processes for solving ODEs are discussed. These methods are the Runge-Kutta method combined with a linear multistep method, which overcomes the defect of the 3rd order parallel Runge-Kutta method discussed in [1].
文摘In this paper, a class of real-time parallel combined methods (RTPCM) of the digital simulation for a partitioned large system is presented. By means of combination of the parallelism across the system with the parallelism across the method, stiff and non-stiff subsystems are solved in parallel on parallel computer by a parallel Rosenbrock method and a parallel RK method, respectively. Their construction, convergence and numerical stability are discussed, and the digitalsimulation experiments are conducted.
基金This project was supported by the National Natural Science Foundation of China (19871080).
文摘A class of modified parallel combined methods of real-time numerical simulation are presented for a stiff dynamic system. By combining the parallelism across the system with the parallelism across the method, and relaxing the dependence of stage value computation on sampling time of input function, a class of modified real-time parallel combined methods are constructed. Stiff and nonstiff subsystems are solved in parallel on a parallel computer by a parallel Rosen-brock method and a parallel RK method, respectively. Their order conditions and convergences are discussed. The numerical simulation experiments show that this class of modified algorithms can get high speed and efficiency.
文摘For a nonlinear limit state function, the first-order reliability method(FORM) may cause large errors in the computation of not only the reliability index or failure probability but also the reliability sensitivity. In order to obtain more the accurate results of the reliability sensitivity analysis, a number of hyperplanes are built near the design point by first-order Tayler series expansion, which replace the known nonlinear limit state hypersurface, and an equivalent computational method is utilized to construct an equivalent hyperplane of the obtained hyperplanes. And the reliability sensitivities can be estimated more accurately by the derived equations based on the equivalent hyperplane. An example shows that the method is effective and feasible.
基金the National Natural Science Foundation of China(Grant Nos.52371342,52271338,52101378 and 51979277)。
文摘This study designs four types of liquid-filled cylindrical shell structures to investigate their protection characteristics against explosive shock waves and high-speed fragments.Bare charge and charge-driven prefabricated fragments are employed to examine the damage under blast shock waves and combined blast and fragments loading on various liquid-filled cylindrical shell structures.The test results are compared to numerical calculations and theoretical analysis for the structure's deformation,the liquid medium's movement,and the pressure waves'propagation characteristics under different liquid-filling methods.The results showed that the filling method influences the blast protection and the struc-ture's energy absorption performance.The external filling method reduces the structural deformation,and the internal filling method increases the damage effect.The gapped internal filling method improves the structure's energy absorption efficiency.The pressure wave loading on the liquid-filled cylindrical shell structure differs depending on filling methods.Explosive shock waves and high-speed fragments show a damage enhancement effect on the liquid-filled cylindrical shell structure,depending on the thickness of the internal liquid container layer.The specific impulse on the inner surface of the cylindrical shell positively correlates to the radial deformation of the cylindrical shell structure,and the external liquid layer limits the radial structural deformation.
基金This project was supported by the National Natural Science Foundation of China (90405011).
文摘A novel control method for a general class of nonlinear systems using fuzzy logic systems （FLSs） is presertted. Indirect and direct methods are combined to design the adaptive fuzzy output feedback controller and a high-gain observer is used to estimate the derivatives of the system output. The closed-loop system is proven to be semiglobally uniformly ultimately bounded. In addition, it is shown that if the approximation accuracy of the fuzzy logic system is high enough and the observer gain is chosen sufficiently large, an arbitrarily small tracking error can be achieved. Simulation results verify the effectiveness of the newly designed scheme and the theoretical discussion.
文摘适应城市化进程加速与气候变化,提高抵御洪涝灾害的能力是可持续发展的必由之路。从韧性视角出发,构建基于“自然-经济-社会-基础设施”的洪涝韧性评估框架,运用组合赋权-逼近理想解排序模型(Technique for Order Preference by Similarity to the Ideal Solution,TOPSIS)评估2007—2022年南京都市圈城市洪涝韧性水平,并利用障碍度模型诊断抑制洪涝韧性提升的主要因素。结果表明:(1)都市圈城市洪涝韧性呈上升趋势,从较低水平转变为中等水平;(2)洪涝韧性空间分布呈现以南京为核心、向四周辐射递减的“中心-外围”特征;(3)研究时段末南京都市圈洪涝韧性的关键限制因素有河流调蓄能力、人口脆弱度、政府财政情况,植被覆盖率为部分城市潜在障碍因素。研究可为南京都市圈完善洪涝灾害防治体系、提升洪涝韧性提供参考。
文摘为建立一种可同时检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法,试验采用正己烷去脂,联合QuEChERS净化结合冷冻脂质过滤法,建立检测鸽蛋中5类24种兽药残留的高效液相色谱-串联质谱法。样品中的5类兽药(氯霉素类、磺胺类、硝基咪唑类、喹诺酮类和抗病毒类)经1.0%乙酸乙腈溶液提取,氮气吹干,冷冻过夜后,结合QuEChERS净化和正己烷去脂,采用1 mL 0.1%甲酸水-乙腈溶液(v/v,90∶10)复溶;高效液相色谱-串联质谱测定,内标法定量,采用实际样品建立方法的初步应用。结果显示:24种兽药在2.0~200 ng/mL线性关系良好(R2>0.99),该方法的定量限为2μg/kg,平均回收率为62.2%~117.1%,相对标准偏差4.3%~18.9%;实际样品检出的7种目标化合物与标准方法相比的相对标准偏差为1.34%~5.20%。研究表明,建立的检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法省去固相萃取步骤,成本较低,灵敏高效,回收率优良、重复性稳定,适用于鸽蛋中多类兽药的快速监测分析。
