The most significant changes of landscape in a certain period are landscape area changes and spatial changes of landscape patches.Based on transfer matrix and total amount change of landscape area,landscape space tran...The most significant changes of landscape in a certain period are landscape area changes and spatial changes of landscape patches.Based on transfer matrix and total amount change of landscape area,landscape space transfer index and landscape area change index were established,and then applied to analyze plain oasis and desert in Yutian County,Xinjiang Uyghur Nationality Autonomous Region,the results showed that landscape space transfer in this region was drastic,but total landscape area changed only slightly,thus space transfer index was much higher than area change index,which indicated that landscapes in arid area were given with particular spatial undulant features and sensitivity,while man-made landscapes(artificial oasis) are stable and expanding to some extent.With landscape space transfer index as the comprehensive indicator,space transfer intensity of landscape within a certain period can be demonstrated,which is favorable for the comparison of landscape change intensity among different types and within different periods,in addition,some macroscopic change features of landscapes can also be reflected by comprehensively analyzing landscape space transfer index and landscape area change index.展开更多
The damped Helmholtz-Duffing oscillator is a topic of great interest in many different fields of study due to its complex dynamics.By transitioning from conventional continuous differential equations to their fractal ...The damped Helmholtz-Duffing oscillator is a topic of great interest in many different fields of study due to its complex dynamics.By transitioning from conventional continuous differential equations to their fractal counterparts,one gains insights into the system's response under new mathematical frameworks.This paper presents a novel method for converting standard continuous differential equations into their fractal equivalents.This conversion occurs after the nonlinear system is transformed into its linear equivalent.Numerical analyses show that there are several resonance sites in the fractal system,which differ from the one resonance point found in the continuous system.One important finding is that the fractal system loses some of its stabilizing power when decaying behavior is transformed into a diffuse pattern.Interestingly,a decrease in the fractal order in resonance settings shows a stabilizing impact,highlighting the dynamics'complexity inside fractal systems.This endeavor to convert to fractals is a revolutionary technique that is being employed for the first time.展开更多
In this paper,using aδ-doping dual-channel structure and GaAs substrate,a real space transfer transistor(RSTT)is designed and fabricated successfully.It has the standardΛ-shaped negative resistance I-V characteristi...In this paper,using aδ-doping dual-channel structure and GaAs substrate,a real space transfer transistor(RSTT)is designed and fabricated successfully.It has the standardΛ-shaped negative resistance I-V characteristics as well as a level and smooth valley region that the conventional RSTT has.The negative resistance parameters can be varied by changing gate voltage(VGS).For example,the PVCR varies from 2.1 to 10.6 while VGS changes from 0.6 V to 1.0 V.The transconductance for IP(ΔIP=ΔVGS)is 0.3 mS.The parameters of VP,VV and threshold gate voltage(VT)for negative resistance characteristics arising are all smaller than the value reported in the literature.Therefore,this device is suitable for low dissipation power application.展开更多
The components of combustion chamber (cylinder head-cylinder liner-piston assembly-oil film) were taken as a coupled body.Based on the three-dimensional heat transfer numerical simulation of the coupled body,a coupled...The components of combustion chamber (cylinder head-cylinder liner-piston assembly-oil film) were taken as a coupled body.Based on the three-dimensional heat transfer numerical simulation of the coupled body,a coupled three-dimensional calculation model for in-cylinder working process and the combustion chamber components was built with domain decomposition and boundary coupled method,which implements the coupled three-dimensional simulation of in-cylinder working process and the combustion chamber components.The model was applied in the influence investigation of the space non-uniformity in heat transfer among combustion chamber components on the generation of in-cylinder emissions:NOx.The results showed that the heat transfer space non-uniformity of combustion chamber components directly influences the formation of in-cylinder NOx.The main area being influenced was the accessory area on the wall,while the influence on the generation of NOx in the central area couold be omitted.展开更多
In this article, a Ky Fan matching theorem for transfer compactly open covers is established. As applications, a Fan-Browder coincidence theorem, a Ky Fan best approximation theorem and a Brouwer-Schauder-Rothe type f...In this article, a Ky Fan matching theorem for transfer compactly open covers is established. As applications, a Fan-Browder coincidence theorem, a Ky Fan best approximation theorem and a Brouwer-Schauder-Rothe type fixed point theorem are obtained.展开更多
High-energy pulsed laser radiation may be the most feasible means to mitigate the threat of collision of a space station or other valuable space assets with orbital debris in the size range of 1–10 cm. Under laser ir...High-energy pulsed laser radiation may be the most feasible means to mitigate the threat of collision of a space station or other valuable space assets with orbital debris in the size range of 1–10 cm. Under laser irradiation, part of the debris material is ablated and provides an impulse to the debris particle. Proper direction of the impulse vector either deflects the object trajectory or forces the debris on a trajectory through the upper atmosphere, where it burns up. Most research concentrates on ground-based laser systems but pays little attention to space-based laser systems.There are drawbacks of a ground-based laser system in cleaning space debris. Therefore the placement of a laser system in space is proposed and investigated. Under assumed conditions,the elimination process of space debris is analyzed. Several factors such as laser repetition frequency, relative movement between the laser and debris, and inclination of debris particles which may exercise influence to the elimination effects are discussed. A project of a space-based laser system is proposed according to the numerical results of a computer study. The proposed laser system can eliminate debris of 1–10 cm and succeed in protecting a space station.展开更多
As serious but neglected public health problems, poor quality medicines, i.e. for antimalarial medicines, urged to be fought. One of the approaches is to consider the analytical chemistry and separative techniques. In...As serious but neglected public health problems, poor quality medicines, i.e. for antimalarial medicines, urged to be fought. One of the approaches is to consider the analytical chemistry and separative techniques. In this study, a generic liquid chromatographic method was firstly developed for the purpose of screening 8 antimalarial active ingredients, namely amodiaquine (AQ), piperaquine (PPQ), sulfalene (SL), pyrimethamine (PM), lumefantrine (LF), artesunate (AS), artemether (AM) and dihydroartemisinine (DHA) by applying DoE/DS optimization strategy. Since the method was not totally satisfying in terms of peak separation, further experiments were undergone applying the same development strategy while splitting the 8 ingredients into five groups. Excellent prediction was observed prior to correlation between retention times of predicted and observed separation conditions. Then, a successful geometric transfer was realized to reduce the analysis time focusing on the simultaneous quantification of two WHO’s recommended ACTs in anti-malarial fixed-dose combination (AM-LF and AS-AQ) in tablets. The optimal separation was achieved using an isocratic elution of methanol-ammonium formate buffer (pH 2.8;10 mM) (82.5:17.5, v/v) at 0.6 ml/min through a C18 column (100 mm × 3.5 mm, 3.5 μm) thermostated at 25℃. After a successful validation stage based on the total error approach, the method was applied to determine the content of AM/LF or AS/AQ in seven brands of antimalarial tablets currently marketed in West, Central and East Africa. Satisfying results were obtained compared to the claimed contents.展开更多
A new notion of finite continuous topological space（in short, FC-space） with out convexity structure was introduced. A new continuous selection theorem was established in FC-spaces. By applying the continuous select...A new notion of finite continuous topological space（in short, FC-space） with out convexity structure was introduced. A new continuous selection theorem was established in FC-spaces. By applying the continuous selection theorem, some new coincidence theorems for two families of set-valued mappings defined on product space of noncompact FC-spaces are proved under much weak assumptions. These results generalize many known results in recent literature. Some applications will be given in a follow-up paper.展开更多
Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor liquid mixture from the heat sur- face and the closed-loop circulat...Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor liquid mixture from the heat sur- face and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space enviromnents. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and exper- imental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 ℃ and 78.2 ℃ under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11,22 L：h to 15.76 L·h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed; results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.展开更多
Image editing is a hot research topic in the image processing region, and one of the most basic problems in this field is the color transfer. It modifies the color style of the target image to match the color palette ...Image editing is a hot research topic in the image processing region, and one of the most basic problems in this field is the color transfer. It modifies the color style of the target image to match the color palette of the source while preserving the content of the target.Although there exist many algorithms to deal with this problem, none of existing methods can handle all kinds of images, especially complex landscape images. In this paper, we propose a Mass Transport based color transfer method in the CIELab color space, which can generate natural transfer results for different kinds of images including landscapes. Different from previous methods using the same transfer model for all the channels, we adopt different models for the luminance channel and color channels. For the luminance channel, a global transfer method is adopted for keeping the consistence in the visual perception. For the color channels,we construct a model based on histogram and Mass Transport, which perfectly transfers the colors of all the pixels from the source to the target and simultaneously preserves the content.What is more, experiments on real images demonstrate that our approach performs favorably against most of the existing methods.展开更多
The purpose to this paper is to study the existence problem of solutions to the vector quasivariational inequality for vector-valued functions inH-space.
This paper is concerned with the optimal design of an obstacle located in the viscous and incompressible fluid which is driven by the steady-state Oseen equations with thermal effects. The structure of shape gradient ...This paper is concerned with the optimal design of an obstacle located in the viscous and incompressible fluid which is driven by the steady-state Oseen equations with thermal effects. The structure of shape gradient of the cost functional is derived by applying the differentiability of a minimax formulation involving a Lagrange functional with a space parametrization technique. A gradient type algorithm is employed to the shape optimization problem. Numerical examples indicate that our theory is useful for practical purpose and the proposed algorithm is feasible.展开更多
Fractional-in-space Allen-Cahn equation containing a very strong nonlinear source term and small perturbation shows metastability and a quartic double well potential.Using a finite volume unstructured triangular mesh ...Fractional-in-space Allen-Cahn equation containing a very strong nonlinear source term and small perturbation shows metastability and a quartic double well potential.Using a finite volume unstructured triangular mesh method, the present paper solves the twodimensional fractional-in-space Allen-Cahn equation with homogeneous Neumann boundary condition on different irregular domains. The efficiency of the method is presented through numerical computation of the two-dimensional fractional-in-space Allen-Cahn equation on different domains.展开更多
基金Supported by National Natural Science Foundation(40661002)Project of National Natural Science Youth Foundation(40701188)Highlevel Talents Initiation Project of Shihezi University(RCZX200693)~~
文摘The most significant changes of landscape in a certain period are landscape area changes and spatial changes of landscape patches.Based on transfer matrix and total amount change of landscape area,landscape space transfer index and landscape area change index were established,and then applied to analyze plain oasis and desert in Yutian County,Xinjiang Uyghur Nationality Autonomous Region,the results showed that landscape space transfer in this region was drastic,but total landscape area changed only slightly,thus space transfer index was much higher than area change index,which indicated that landscapes in arid area were given with particular spatial undulant features and sensitivity,while man-made landscapes(artificial oasis) are stable and expanding to some extent.With landscape space transfer index as the comprehensive indicator,space transfer intensity of landscape within a certain period can be demonstrated,which is favorable for the comparison of landscape change intensity among different types and within different periods,in addition,some macroscopic change features of landscapes can also be reflected by comprehensively analyzing landscape space transfer index and landscape area change index.
文摘The damped Helmholtz-Duffing oscillator is a topic of great interest in many different fields of study due to its complex dynamics.By transitioning from conventional continuous differential equations to their fractal counterparts,one gains insights into the system's response under new mathematical frameworks.This paper presents a novel method for converting standard continuous differential equations into their fractal equivalents.This conversion occurs after the nonlinear system is transformed into its linear equivalent.Numerical analyses show that there are several resonance sites in the fractal system,which differ from the one resonance point found in the continuous system.One important finding is that the fractal system loses some of its stabilizing power when decaying behavior is transformed into a diffuse pattern.Interestingly,a decrease in the fractal order in resonance settings shows a stabilizing impact,highlighting the dynamics'complexity inside fractal systems.This endeavor to convert to fractals is a revolutionary technique that is being employed for the first time.
文摘In this paper,using aδ-doping dual-channel structure and GaAs substrate,a real space transfer transistor(RSTT)is designed and fabricated successfully.It has the standardΛ-shaped negative resistance I-V characteristics as well as a level and smooth valley region that the conventional RSTT has.The negative resistance parameters can be varied by changing gate voltage(VGS).For example,the PVCR varies from 2.1 to 10.6 while VGS changes from 0.6 V to 1.0 V.The transconductance for IP(ΔIP=ΔVGS)is 0.3 mS.The parameters of VP,VV and threshold gate voltage(VT)for negative resistance characteristics arising are all smaller than the value reported in the literature.Therefore,this device is suitable for low dissipation power application.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 50576008,50876016,and 51006015)
文摘The components of combustion chamber (cylinder head-cylinder liner-piston assembly-oil film) were taken as a coupled body.Based on the three-dimensional heat transfer numerical simulation of the coupled body,a coupled three-dimensional calculation model for in-cylinder working process and the combustion chamber components was built with domain decomposition and boundary coupled method,which implements the coupled three-dimensional simulation of in-cylinder working process and the combustion chamber components.The model was applied in the influence investigation of the space non-uniformity in heat transfer among combustion chamber components on the generation of in-cylinder emissions:NOx.The results showed that the heat transfer space non-uniformity of combustion chamber components directly influences the formation of in-cylinder NOx.The main area being influenced was the accessory area on the wall,while the influence on the generation of NOx in the central area couold be omitted.
基金This work is supported by the Scientific Research Foundation of Bijie University.
文摘In this article, a Ky Fan matching theorem for transfer compactly open covers is established. As applications, a Fan-Browder coincidence theorem, a Ky Fan best approximation theorem and a Brouwer-Schauder-Rothe type fixed point theorem are obtained.
基金supported by the National Natural Science Foundation of China(No:11102234)Provincial Level Project of China
文摘High-energy pulsed laser radiation may be the most feasible means to mitigate the threat of collision of a space station or other valuable space assets with orbital debris in the size range of 1–10 cm. Under laser irradiation, part of the debris material is ablated and provides an impulse to the debris particle. Proper direction of the impulse vector either deflects the object trajectory or forces the debris on a trajectory through the upper atmosphere, where it burns up. Most research concentrates on ground-based laser systems but pays little attention to space-based laser systems.There are drawbacks of a ground-based laser system in cleaning space debris. Therefore the placement of a laser system in space is proposed and investigated. Under assumed conditions,the elimination process of space debris is analyzed. Several factors such as laser repetition frequency, relative movement between the laser and debris, and inclination of debris particles which may exercise influence to the elimination effects are discussed. A project of a space-based laser system is proposed according to the numerical results of a computer study. The proposed laser system can eliminate debris of 1–10 cm and succeed in protecting a space station.
文摘As serious but neglected public health problems, poor quality medicines, i.e. for antimalarial medicines, urged to be fought. One of the approaches is to consider the analytical chemistry and separative techniques. In this study, a generic liquid chromatographic method was firstly developed for the purpose of screening 8 antimalarial active ingredients, namely amodiaquine (AQ), piperaquine (PPQ), sulfalene (SL), pyrimethamine (PM), lumefantrine (LF), artesunate (AS), artemether (AM) and dihydroartemisinine (DHA) by applying DoE/DS optimization strategy. Since the method was not totally satisfying in terms of peak separation, further experiments were undergone applying the same development strategy while splitting the 8 ingredients into five groups. Excellent prediction was observed prior to correlation between retention times of predicted and observed separation conditions. Then, a successful geometric transfer was realized to reduce the analysis time focusing on the simultaneous quantification of two WHO’s recommended ACTs in anti-malarial fixed-dose combination (AM-LF and AS-AQ) in tablets. The optimal separation was achieved using an isocratic elution of methanol-ammonium formate buffer (pH 2.8;10 mM) (82.5:17.5, v/v) at 0.6 ml/min through a C18 column (100 mm × 3.5 mm, 3.5 μm) thermostated at 25℃. After a successful validation stage based on the total error approach, the method was applied to determine the content of AM/LF or AS/AQ in seven brands of antimalarial tablets currently marketed in West, Central and East Africa. Satisfying results were obtained compared to the claimed contents.
基金Project supported by the Natural Science Foundation of Education Department of Sichuan Province (No.2003A081)the Constructed Foundation of Key Disciplines of Sichuan Province (No.0406)
文摘A new notion of finite continuous topological space（in short, FC-space） with out convexity structure was introduced. A new continuous selection theorem was established in FC-spaces. By applying the continuous selection theorem, some new coincidence theorems for two families of set-valued mappings defined on product space of noncompact FC-spaces are proved under much weak assumptions. These results generalize many known results in recent literature. Some applications will be given in a follow-up paper.
基金supported by the National Natural Science Foundation of China(No.50506003)
文摘Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor liquid mixture from the heat sur- face and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space enviromnents. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and exper- imental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 ℃ and 78.2 ℃ under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11,22 L：h to 15.76 L·h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed; results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.
文摘Image editing is a hot research topic in the image processing region, and one of the most basic problems in this field is the color transfer. It modifies the color style of the target image to match the color palette of the source while preserving the content of the target.Although there exist many algorithms to deal with this problem, none of existing methods can handle all kinds of images, especially complex landscape images. In this paper, we propose a Mass Transport based color transfer method in the CIELab color space, which can generate natural transfer results for different kinds of images including landscapes. Different from previous methods using the same transfer model for all the channels, we adopt different models for the luminance channel and color channels. For the luminance channel, a global transfer method is adopted for keeping the consistence in the visual perception. For the color channels,we construct a model based on histogram and Mass Transport, which perfectly transfers the colors of all the pixels from the source to the target and simultaneously preserves the content.What is more, experiments on real images demonstrate that our approach performs favorably against most of the existing methods.
基金Supported by the Science Research Foundation of Xianning Teacher's College( No.K9911)
文摘The purpose to this paper is to study the existence problem of solutions to the vector quasivariational inequality for vector-valued functions inH-space.
文摘This paper is concerned with the optimal design of an obstacle located in the viscous and incompressible fluid which is driven by the steady-state Oseen equations with thermal effects. The structure of shape gradient of the cost functional is derived by applying the differentiability of a minimax formulation involving a Lagrange functional with a space parametrization technique. A gradient type algorithm is employed to the shape optimization problem. Numerical examples indicate that our theory is useful for practical purpose and the proposed algorithm is feasible.
基金Supported by the National Natural Science Foundation of China(11105040,61773153)Supported by the Foundation of Henan Educational Committee(18B110003,15A110015)+1 种基金Supported by the Excellent Young Scientific Talents Cultivation Foundation of Henan University(yqpy20140037)Supported by the Science and Technology Program of Henan Province(162300410061)
文摘Fractional-in-space Allen-Cahn equation containing a very strong nonlinear source term and small perturbation shows metastability and a quartic double well potential.Using a finite volume unstructured triangular mesh method, the present paper solves the twodimensional fractional-in-space Allen-Cahn equation with homogeneous Neumann boundary condition on different irregular domains. The efficiency of the method is presented through numerical computation of the two-dimensional fractional-in-space Allen-Cahn equation on different domains.
