Infrared false target is an important mean to induce the infrared-guided weapons,and the key issue is how to keep the surface temperature of the infrared false target to be the same as that of the object to be protect...Infrared false target is an important mean to induce the infrared-guided weapons,and the key issue is how to keep the surface temperature of the infrared false target to be the same as that of the object to be protected.One-dimensional heat transfer models of a metal plate and imitative material were established to explore the influences of the thermophysical properties of imitative material on the surface temperature difference（STD） between the metal plate and imitative material which were subjected to periodical ambient conditions.It is elucidated that the STD is determined by the imitative material’s dimensionless thickness（dim*,） and the thermal inertia(Pim).When dim* is above 1.0,the STD is invariable as long as Pim is a constant.And if the dimensionless thickness of metal plate（d,m*） is also larger than 1.0,the STD approaches to zero as long as Pimis the same as the thermal inertia of metal plate（Pm）.When dim* is between 0.08 and 1,the STD varies irregularly with Pim and dim*.However,if dm* is also in the range of 0.08-1,the STD approaches to zero on condition that Pim=Pm and dim*= dm*.If dim*,is below 0.08,the STD is unchanged when Pimdim* is a constant.And if dm* is also less than 0.08,the STD approaches to zero as long as Pimdim* = Pmdm*.Furthermore,an applicationoriented discussion indicates that the imitative material can be both light and thin via the application of the phase change material with a preset STD because of its high specific heat capacity during the phase transition process.展开更多
The article studies the evolutionary dynamics of two-population two-strategy game models with and without impulses. First, the payment matrix is given and two evolutionary dynamics models are established by adding sto...The article studies the evolutionary dynamics of two-population two-strategy game models with and without impulses. First, the payment matrix is given and two evolutionary dynamics models are established by adding stochastic and impulse. For the stochastic model without impulses, the existence and uniqueness of solution, and the existence of positive periodic solutions are proved, and a sufficient condition for strategy extinction is given. For the stochastic model with impulses, the existence of positive periodic solutions is proved. Numerical results show that noise and impulses directly affect the model, but the periodicity of the model does not change.展开更多
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
In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave so...In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave solutions for this model under the influence of advection term and distributed delay.The obtained results indicate that weak kernel and strong kernel can both deduce the existence of periodic traveling wave solutions.Finally,we apply the main results in this paper to Logistic model and Nicholson’s blowflies model.展开更多
Performance-based warranties(PBWs)are widely used in industry and manufacturing.Given that PBW can impose financial burdens on manufacturers,rational maintenance decisions are essential for expanding profit margins.Th...Performance-based warranties(PBWs)are widely used in industry and manufacturing.Given that PBW can impose financial burdens on manufacturers,rational maintenance decisions are essential for expanding profit margins.This paper proposes an optimization model for PBW decisions for systems affected by Gamma degradation processes,incorporating periodic inspection.A system performance degradation model is established.Preventive maintenance probability and corrective renewal probability models are developed to calculate expected warranty costs and system availability.A benefits function,which includes incentives,is constructed to optimize the initial and subsequent inspection intervals and preventive maintenance thresholds,thereby maximizing warranty profit.An improved sparrow search algorithm is developed to optimize the model,with a case study on large steam turbine rotor shafts.The results suggest the optimal PBW strategy involves an initial inspection interval of approximately 20 months,with subsequent intervals of about four months,and a preventive maintenance threshold of approximately 37.39 mm wear.When compared to common cost-minimization-based condition maintenance strategies and PBW strategies that do not differentiate between initial and subsequent inspection intervals,the proposed PBW strategy increases the manufacturer’s profit by 1%and 18%,respectively.Sensitivity analyses provide managerial recommendations for PBW implementation.The PBW strategy proposed in this study significantly increases manufacturers’profits by optimizing inspection intervals and preventive maintenance thresholds,and manufacturers should focus on technological improvement in preventive maintenance and cost control to further enhance earnings.展开更多
In this paper,the isogeometric analysis(IGA)method is employed to analyze the oscillation characteristics of functionally graded triply periodic minimal surface(FG-TPMS)curved-doubly shells integrated with magneto-ele...In this paper,the isogeometric analysis(IGA)method is employed to analyze the oscillation characteristics of functionally graded triply periodic minimal surface(FG-TPMS)curved-doubly shells integrated with magneto-electric surface layers(referred to as"FG-TPMS-MEE curved-doubly shells")subjected to low-velocity impact loads.This study presents low-velocity impact load model based on a single springmass(S-M)approach.The FG-TPMS-MEE curved-doubly shells are covered with two magneto-electric surface layers,while the core layer consists of three types:I-graph and Wrapped Package-graph(IWP),Gyroid(G),and Primitive(P),with various graded functions.These types are notable for their exceptional stiffness-to-weight ratios,enabling a wide range of potential applications.The Maxwell equations and electromagnetic boundary conditions are applied to compute the change in electric potentials and magnetic potentials.The equilibrium equations of the shell are derived from a refined higher-order shear deformation theory(HSDT),and the transient responses of the FG-TPMS-MEE curveddoubly shells are subsequently determined using Newmark's direct integration method.These results have applications in structural vibration control and the analysis of structures subjected to impact or explosive loads.Furthermore,this study provides a theoretical prediction of the low-velocity impact load and magneto-electric-elastic effects on the free vibration and transient response of FG-TPMS-MEE curved-doubly shells.展开更多
针对广东电网公司对谐波检测技术在电能计量自动化系统中的应用需求,首次提出了谐波检测在计量自动化终端中的实现方法。研究EDIT-FFT(equal decimation in time fast Fourier transformation)算法对采样信号进行处理得到分次谐波畸变率...针对广东电网公司对谐波检测技术在电能计量自动化系统中的应用需求,首次提出了谐波检测在计量自动化终端中的实现方法。研究EDIT-FFT(equal decimation in time fast Fourier transformation)算法对采样信号进行处理得到分次谐波畸变率,并结合电能数据固定、平滑、短数据帧的特点,研究RAY-Period压缩算法并首次应用到智能计量自动化终端,解决了存储空间以及与主站通讯两方面的问题。该文的研究为广东电网公司的电能计量自动化系统的功能完善打下了坚实的基础。展开更多
The journal is sponsored by the Chinese Association of Animal Science and Veterinary Medicine.It is a national academic journal,founded in 1956,in the area of animal and veterinary medical sciences.The editorial board...The journal is sponsored by the Chinese Association of Animal Science and Veterinary Medicine.It is a national academic journal,founded in 1956,in the area of animal and veterinary medical sciences.The editorial board of the journal,which is located in Institute of Animal Science of the Chinese Academy of Agricultural Sciences,is responsible for the editing and publishing of the journal.展开更多
Journal of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society, is published quarterly. This journal is a representative of publications of the academic circles specializing chiefly
Journal of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society,is published quarterly. This journal is a representative of publications of the academic circles specializing chiefly
Journal of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society,ispublished quarterly.This journal is a representative of publications of the academic circles specializing chiefly in the...Journal of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society,ispublished quarterly.This journal is a representative of publications of the academic circles specializing chiefly in the field of ordnance science and technology.展开更多
Journsl of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society, is published quarterly.This journal is a representative of publications of the academic circles specializing chiefly in t...Journsl of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society, is published quarterly.This journal is a representative of publications of the academic circles specializing chiefly in the field of ordnance science and technology. Contributions within the above scope all over the world展开更多
1 Journal of Yunnan Agricultural University(Natural science edition)is sponsored byYunnan Agricultural University,and is a com-prehensive scientific periodical publication inChina and abroad.The main report aspectsare...1 Journal of Yunnan Agricultural University(Natural science edition)is sponsored byYunnan Agricultural University,and is a com-prehensive scientific periodical publication inChina and abroad.The main report aspectsare research thesis,research report,researchbulletin and summary of subject progress thatinvolves basic research as well as applicationand development research of agriculture,biolo-gy and related subjects,etc.展开更多
基金funded by the National Natural Science Foundation of China (No. 51576188)
文摘Infrared false target is an important mean to induce the infrared-guided weapons,and the key issue is how to keep the surface temperature of the infrared false target to be the same as that of the object to be protected.One-dimensional heat transfer models of a metal plate and imitative material were established to explore the influences of the thermophysical properties of imitative material on the surface temperature difference（STD） between the metal plate and imitative material which were subjected to periodical ambient conditions.It is elucidated that the STD is determined by the imitative material’s dimensionless thickness（dim*,） and the thermal inertia(Pim).When dim* is above 1.0,the STD is invariable as long as Pim is a constant.And if the dimensionless thickness of metal plate（d,m*） is also larger than 1.0,the STD approaches to zero as long as Pimis the same as the thermal inertia of metal plate（Pm）.When dim* is between 0.08 and 1,the STD varies irregularly with Pim and dim*.However,if dm* is also in the range of 0.08-1,the STD approaches to zero on condition that Pim=Pm and dim*= dm*.If dim*,is below 0.08,the STD is unchanged when Pimdim* is a constant.And if dm* is also less than 0.08,the STD approaches to zero as long as Pimdim* = Pmdm*.Furthermore,an applicationoriented discussion indicates that the imitative material can be both light and thin via the application of the phase change material with a preset STD because of its high specific heat capacity during the phase transition process.
基金Supported by the National Natural Science Foundation of China(10671182)。
文摘The article studies the evolutionary dynamics of two-population two-strategy game models with and without impulses. First, the payment matrix is given and two evolutionary dynamics models are established by adding stochastic and impulse. For the stochastic model without impulses, the existence and uniqueness of solution, and the existence of positive periodic solutions are proved, and a sufficient condition for strategy extinction is given. For the stochastic model with impulses, the existence of positive periodic solutions is proved. Numerical results show that noise and impulses directly affect the model, but the periodicity of the model does not change.
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 National Natural Science Foundation of China(12261050)Science and Technology Project of Department of Education of Jiangxi Province(GJJ2201612 and GJJ211027)Natural Science Foundation of Jiangxi Province of China(20212BAB202021)。
文摘In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave solutions for this model under the influence of advection term and distributed delay.The obtained results indicate that weak kernel and strong kernel can both deduce the existence of periodic traveling wave solutions.Finally,we apply the main results in this paper to Logistic model and Nicholson’s blowflies model.
基金supported by the National Natural Science Foundation of China(71871219).
文摘Performance-based warranties(PBWs)are widely used in industry and manufacturing.Given that PBW can impose financial burdens on manufacturers,rational maintenance decisions are essential for expanding profit margins.This paper proposes an optimization model for PBW decisions for systems affected by Gamma degradation processes,incorporating periodic inspection.A system performance degradation model is established.Preventive maintenance probability and corrective renewal probability models are developed to calculate expected warranty costs and system availability.A benefits function,which includes incentives,is constructed to optimize the initial and subsequent inspection intervals and preventive maintenance thresholds,thereby maximizing warranty profit.An improved sparrow search algorithm is developed to optimize the model,with a case study on large steam turbine rotor shafts.The results suggest the optimal PBW strategy involves an initial inspection interval of approximately 20 months,with subsequent intervals of about four months,and a preventive maintenance threshold of approximately 37.39 mm wear.When compared to common cost-minimization-based condition maintenance strategies and PBW strategies that do not differentiate between initial and subsequent inspection intervals,the proposed PBW strategy increases the manufacturer’s profit by 1%and 18%,respectively.Sensitivity analyses provide managerial recommendations for PBW implementation.The PBW strategy proposed in this study significantly increases manufacturers’profits by optimizing inspection intervals and preventive maintenance thresholds,and manufacturers should focus on technological improvement in preventive maintenance and cost control to further enhance earnings.
文摘In this paper,the isogeometric analysis(IGA)method is employed to analyze the oscillation characteristics of functionally graded triply periodic minimal surface(FG-TPMS)curved-doubly shells integrated with magneto-electric surface layers(referred to as"FG-TPMS-MEE curved-doubly shells")subjected to low-velocity impact loads.This study presents low-velocity impact load model based on a single springmass(S-M)approach.The FG-TPMS-MEE curved-doubly shells are covered with two magneto-electric surface layers,while the core layer consists of three types:I-graph and Wrapped Package-graph(IWP),Gyroid(G),and Primitive(P),with various graded functions.These types are notable for their exceptional stiffness-to-weight ratios,enabling a wide range of potential applications.The Maxwell equations and electromagnetic boundary conditions are applied to compute the change in electric potentials and magnetic potentials.The equilibrium equations of the shell are derived from a refined higher-order shear deformation theory(HSDT),and the transient responses of the FG-TPMS-MEE curveddoubly shells are subsequently determined using Newmark's direct integration method.These results have applications in structural vibration control and the analysis of structures subjected to impact or explosive loads.Furthermore,this study provides a theoretical prediction of the low-velocity impact load and magneto-electric-elastic effects on the free vibration and transient response of FG-TPMS-MEE curved-doubly shells.
文摘针对广东电网公司对谐波检测技术在电能计量自动化系统中的应用需求,首次提出了谐波检测在计量自动化终端中的实现方法。研究EDIT-FFT(equal decimation in time fast Fourier transformation)算法对采样信号进行处理得到分次谐波畸变率,并结合电能数据固定、平滑、短数据帧的特点,研究RAY-Period压缩算法并首次应用到智能计量自动化终端,解决了存储空间以及与主站通讯两方面的问题。该文的研究为广东电网公司的电能计量自动化系统的功能完善打下了坚实的基础。
文摘The journal is sponsored by the Chinese Association of Animal Science and Veterinary Medicine.It is a national academic journal,founded in 1956,in the area of animal and veterinary medical sciences.The editorial board of the journal,which is located in Institute of Animal Science of the Chinese Academy of Agricultural Sciences,is responsible for the editing and publishing of the journal.
文摘Journal of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society, is published quarterly. This journal is a representative of publications of the academic circles specializing chiefly
文摘Journal of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society,is published quarterly. This journal is a representative of publications of the academic circles specializing chiefly
文摘Journal of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society,ispublished quarterly.This journal is a representative of publications of the academic circles specializing chiefly in the field of ordnance science and technology.
文摘Journsl of China Ordnance A comprehensive academic journal sponsored by China Ordnance Society, is published quarterly.This journal is a representative of publications of the academic circles specializing chiefly in the field of ordnance science and technology. Contributions within the above scope all over the world
文摘1 Journal of Yunnan Agricultural University(Natural science edition)is sponsored byYunnan Agricultural University,and is a com-prehensive scientific periodical publication inChina and abroad.The main report aspectsare research thesis,research report,researchbulletin and summary of subject progress thatinvolves basic research as well as applicationand development research of agriculture,biolo-gy and related subjects,etc.
