It is a challenge to polish the interior surface of an additively manufactured component with complex structures and groove sizes less than 1 mm.Traditional polishing methods are disabled to polish the component,meanw...It is a challenge to polish the interior surface of an additively manufactured component with complex structures and groove sizes less than 1 mm.Traditional polishing methods are disabled to polish the component,meanwhile keeping the structure intact.To overcome this challenge,small-grooved components made of aluminum alloy with sizes less than 1 mm were fabricated by a custom-made printer.A novel approach to multi-phase jet(MPJ)polishing is proposed,utilizing a self-developed polisher that incorporates solid,liquid,and gas phases.In contrast,abrasive air jet(AAJ)polishing is recommended,employing a customized polisher that combines solid and gas phases.After jet polishing,surface roughness(Sa)on the interior surface of grooves decreases from pristine 8.596μm to 0.701μm and 0.336μm via AAJ polishing and MPJ polishing,respectively,and Sa reduces 92%and 96%,correspondingly.Furthermore,a formula defining the relationship between linear energy density and unit defect volume has been developed.The optimized parameters in additive manufacturing are that linear energy density varies from 0.135 J mm^(-1)to 0.22 J mm^(-1).The unit area defect volume achieved via the optimized parameters decreases to 1/12 of that achieved via non-optimized ones.Computational fluid dynamics simulation results reveal that material is removed by shear stress,and the alumina abrasives experience multiple collisions with the defects on the heat pipe groove,resulting in uniform material removal.This is in good agreement with the experimental results.The novel proposed setups,approach,and findings provide new insights into manufacturing complex-structured components,polishing the small-grooved structure,and keeping it unbroken.展开更多
We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and...We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and possesses different transmission conditions.Using the variational method,we obtain the well posedness of the interior transmission problem,which plays an important role in the proof of the discreteness of eigenvalues.Then we achieve the existence of an infinite discrete set of transmission eigenvalues provided that n≡1,where a fourth order differential operator is applied.In the case of n■1,we show the discreteness of the transmission eigenvalues under restrictive assumptions by the analytic Fredholm theory and the T-coercive method.展开更多
Understanding digital technology requires a shift in mindset that takes into account the broader implications of design,social dynamics,environmental factors,and cultural influences.Acknowledging the fact that technol...Understanding digital technology requires a shift in mindset that takes into account the broader implications of design,social dynamics,environmental factors,and cultural influences.Acknowledging the fact that technology is not confined to the virtual domain but rather has a tangible influence on our daily lives and the surrounding environment,the extensive integration and potential of digital technologies offer a distinctive prospect to fundamentally transform our shared comprehension of architecture.Digital technologies are revolutionizing design practices,manufacturing processes,and our engagement with and understanding of the built environment,by fostering the development of novel models that promote equity and inclusivity.The application of“digital technologies”can function as a methodology for examining and expressing the possible paths of emerging digital technologies.Extrapolate the expected impact of digital technologies on the design,development,and occupancy of the environment to achieve a more sustainable future in the long run.This paper will examine the potential connections and origins of digital technology concerning modularity,as well as the implications of modularity on forthcoming architectural developments in customization.展开更多
Nowadays,the elderly have become an increasingly large group of people in China,but still many problems exist in their living space.This paper explores the physiological and psychological behavioral changes of the eld...Nowadays,the elderly have become an increasingly large group of people in China,but still many problems exist in their living space.This paper explores the physiological and psychological behavioral changes of the elderly,studies their living space requirements,and tries to put forward targeted design strategies in response.Therefore,making a better and more reasonable living space for the elderly as well as improving their living quality,finally helping the development of elderly-friendly design in China.展开更多
To further enhance the effectiveness of talent cultivation for interior design in vocational colleges,it is necessary to vigorously promote the construction of an industry-education integration model.Through this mode...To further enhance the effectiveness of talent cultivation for interior design in vocational colleges,it is necessary to vigorously promote the construction of an industry-education integration model.Through this model,the roles of both enterprises and schools can be leveraged to jointly facilitate the continuous improvement of students’professional abilities and practical skills,providing a steady stream of high-quality talents for the development of the interior design field.Therefore,this paper analyzes the current issues in interior design talent cultivation in vocational colleges from the perspective of industry-education integration and proposes corresponding improvement measures.展开更多
This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior mag...This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor(IPMSM)drive systems.The mathematical model of flux weakening(FW)control is established,and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve.Next,a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time.Then,an extended sliding mode disturbance observer(ESMDO)is designed to estimate the uncertainty of the system.Finally,compared with both the PI control and sliding mode control(SMC)by simulations and experiments with different working conditions,the method proposed has the merits of accelerating convergence,improving steady-state accuracy,and minimizing the current and torque pulsation.展开更多
The Great Plague:The Diary of Alice Paynton,London 1665-1666 adopts the realistic painting style and direct writing to the painful experience,describes the situation of the Great Plague in London truly from the perspe...The Great Plague:The Diary of Alice Paynton,London 1665-1666 adopts the realistic painting style and direct writing to the painful experience,describes the situation of the Great Plague in London truly from the perspective of children,and breaks people’s cognitive expectation of children’s literature,the construction of children’s Gray inner world is completed behind the true description of the Great Plague in London with the true brushwork,which presents a different world of childlike innocence.Despite the importance of epidemics writing in literature,the child’s diary perspective of them is one of the least developed of Plague Narrative.Only when authenticity and the child’s grey interior are integrated will we reveal a true picture of society as it was.展开更多
Based on the ideological and political requirements of interior design professional courses,exploring the integrated education path of professional plus innovation and entrepreneurship requires first expanding the ide...Based on the ideological and political requirements of interior design professional courses,exploring the integrated education path of professional plus innovation and entrepreneurship requires first expanding the ideological and political content of professional introductory courses,core courses,and expanded courses.Then,we will reshape the curriculum system based on the principle of connecting professional teaching and ideological and political courses,focusing on the realistic principle of talent needs,striving for student growth,adjusting the course content,optimizing the teaching model,and transforming teaching through in-and out-of-class practice and counterpoint guidance.展开更多
For higher vocational colleges,skills competition is an important indicator of professional personnel training quality.In this paper,the architectural interior design professional skills competition in Chongqing Energ...For higher vocational colleges,skills competition is an important indicator of professional personnel training quality.In this paper,the architectural interior design professional skills competition in Chongqing Energy Vocational College is taken as an example,the many years of teaching and competition experience are taken into account,the problems existing in the cultivation of architectural interior design professionals in higher vocational colleges are analyzed,and corresponding solutions are proposed.展开更多
Peking Union Medical College was founded in the late Qing Dynasty and the early Republic of China.Since then,society and politics have been rapidly changing,and its architectural aesthetics reflect the idea of advocat...Peking Union Medical College was founded in the late Qing Dynasty and the early Republic of China.Since then,society and politics have been rapidly changing,and its architectural aesthetics reflect the idea of advocating the West and inheriting tradition.Through research and actual investigation,this paper summarizes the current status of its building from two aspects,interior decoration art and interior decoration technology,analyzes the interior decoration characteristics of Peking Union Medical College Phase I Project,and records the archives of Peking Union Medical College’s decoration technology.展开更多
“Internet Plus”thinking has been widely adopted in the teaching of interior design in colleges and universities,and its application has significant implications that cannot be disregarded.“Internet Plus”thinking n...“Internet Plus”thinking has been widely adopted in the teaching of interior design in colleges and universities,and its application has significant implications that cannot be disregarded.“Internet Plus”thinking not only realizes the innovation of interior design teaching but also significantly improves the level and quality of teaching.Through an analysis of the advantages of“Internet Plus”education platform and the current situation of higher vocational interior design teaching,effective strategies for higher vocational interior design teaching based on“Internet Plus”thinking are proposed in this paper in hope that this study will contribute to the efficient development of interior design teaching activities.展开更多
By using function one direction S-rough sets,the concept of F-interior hiding image is presented; the theorem of F-interior hiding and the recognition criteria of interior hiding are proposed; and the applications of ...By using function one direction S-rough sets,the concept of F-interior hiding image is presented; the theorem of F-interior hiding and the recognition criteria of interior hiding are proposed; and the applications of F-interior hiding image are given. F-interior hiding image is a new application area of function S-rough sets,and function S-rough sets is a new theory and new tools for iconology research.展开更多
Cluster warhead dispersing technique is analyzed with gas dynamic theory. It is seen that the front cover opening and two stage dispersing system is suitable for guided sub missiles whose number is not so large. Th...Cluster warhead dispersing technique is analyzed with gas dynamic theory. It is seen that the front cover opening and two stage dispersing system is suitable for guided sub missiles whose number is not so large. The interior ballistic performances of this system are calculated with numerical calculation method. The performances such as the pressure in the pressure chambers and the velocity of the sub missiles are obtained in curve form.展开更多
In this paper, an Improved Affine-Scaling Interior Point Algorithm for Linear Programming has been proposed. Computational results of selected practical problems affirming the proposed algorithm have been provided. Th...In this paper, an Improved Affine-Scaling Interior Point Algorithm for Linear Programming has been proposed. Computational results of selected practical problems affirming the proposed algorithm have been provided. The proposed algorithm is accurate, faster and therefore reduces the number of iterations required to obtain an optimal solution of a given Linear Programming problem as compared to the already existing Affine-Scaling Interior Point Algorithm. The algorithm can be very useful for development of faster software packages for solving linear programming problems using the interior-point methods.展开更多
From the creation,materials,colors and technical artistic characteristics of exterior and exterior spatial decoration,the artistic value of ancient Huizhou folk houses were analyzed.
Through analyzing the basic structure of ancient Huizhou vernacular dwellings and the spatial order of interior decoration,this study rethought profoundly about modern interior design and put forward the inheritance o...Through analyzing the basic structure of ancient Huizhou vernacular dwellings and the spatial order of interior decoration,this study rethought profoundly about modern interior design and put forward the inheritance of traditional methods in interior decoration.展开更多
Landscape plants play a role of decorating and beautifying the indoor environment.From the perspective of humanization,the functions and application patterns of landscape plants in the interior environmental design ar...Landscape plants play a role of decorating and beautifying the indoor environment.From the perspective of humanization,the functions and application patterns of landscape plants in the interior environmental design are analyzed in this study,and finally the application rules of landscape plants in the humanized interior environmental design are summarized.展开更多
Measurements of Jupiter’s gravity field by Juno have been acquired with unprecedented precision, but uncertainties in the planet’s hydrogen–helium equation of state(EOS) and the hydrogen–helium phase separation ha...Measurements of Jupiter’s gravity field by Juno have been acquired with unprecedented precision, but uncertainties in the planet’s hydrogen–helium equation of state(EOS) and the hydrogen–helium phase separation have meant that differences remain in the interior model predictions. We deduce an empirical EOS from Juno gravity field observations in terms of the hydrostatic equation and then investigate the structure and composition of Jupiter by comparison of the empirical EOS with Jupiter’s adiabats obtained from the physical EOS. The deduced helium mass fraction suggests depletion of helium in the outermost atmosphere and helium concentration in the inner molecular hydrogen region, which is a signature of helium rain in Jupiter’s interior. The deduced envelope metallicity(the heavy-element mass fraction) is as high in the innermost envelope as 11–13 times the solar value. Such a high metallicity provides sharp support to the dilute core model with the heavy elements dissolved in hydrogen and expanded outward. No matter how the core mass is varied, the empirical EOS derived from the two-layer interior model generally suggests higher densities in the innermost envelope than does the best-fit Jupiter’s adiabat;this result is, again, a signature of dilute cores in Jupiter’s interior. Moreover, no matter the core mass,the empirical EOS is found to exhibit an inflexion point in the deep interior, around 10 Mbar, which can be explained as the combined effect of helium concentration in the upper part and dilute cores in the lower part.展开更多
This article uses nonlinear dynamics analysis software AUTODYN-2D to establish an interior ballistic model of cen- tral blast tube cluster munitions dispersion. The interior ballistic process of the central blast tube...This article uses nonlinear dynamics analysis software AUTODYN-2D to establish an interior ballistic model of cen- tral blast tube cluster munitions dispersion. The interior ballistic process of the central blast tube duster munitions dispersion was simulated. The state of submunitions dispersion was obtained as interior ballistic conditions changed. The effect of shell stress groove on shell opening was discussed. The shell with stree groove is helpful for submunitions dispensing effectively and uniformly. The effect of liner material on submunitions dispersing was discussed. It can be found that foam liner can reduce the interior ballistic pressure, increase the pressure action time, reduce the acceleration of the submunitions and increase the sub- munitions dispersing velocity. These results provide some reference for the theory and experiment research of the central blast tube cluster munitions dispersion.展开更多
Noise is one of the key issues in the operation of high-speed railways, with sound source localisation and its transfer path as the two major aspects. This study investigates both the exterior and interior sound sourc...Noise is one of the key issues in the operation of high-speed railways, with sound source localisation and its transfer path as the two major aspects. This study investigates both the exterior and interior sound source distribution of a high-speed train and presents a method for performing the contribution analysis of airborne sound with regard to the interior noise. First, both exterior and interior sound source locations of the high-speed train are identified through in-situ measurements. Second, the sound source contribution for di erent regions of the train and the relationships between the exterior and interior noises are analysed. Third, a method for conducting the contribution analysis of airborne sound with regard to the interior noise of the high-speed train is described. Lastly, a case study on the sidewall area is carried out, and the contribution of airborne sound to the interior noise of this area is obtained. The results show that, when the high-speed train runs at 310 km/h, dominant exterior sound sources are located in the bogie and pantograph regions, while main interior sound sources are located at the sidewall and roof. The interior noise, the bogie area noise and the sound source at the middle of the coach exhibit very similar rates of increase with increasing train speed. For the selected sidewall area, structure-borne sound dominates in most of the 1/3 octave bands.展开更多
基金the National Key Research and Development Program of China(2018YFA0703400)the Young Scientists Fund of the National Natural Science Foundation of China(52205447)Changjiang Scholars Program of the Chinese Ministry of Education。
文摘It is a challenge to polish the interior surface of an additively manufactured component with complex structures and groove sizes less than 1 mm.Traditional polishing methods are disabled to polish the component,meanwhile keeping the structure intact.To overcome this challenge,small-grooved components made of aluminum alloy with sizes less than 1 mm were fabricated by a custom-made printer.A novel approach to multi-phase jet(MPJ)polishing is proposed,utilizing a self-developed polisher that incorporates solid,liquid,and gas phases.In contrast,abrasive air jet(AAJ)polishing is recommended,employing a customized polisher that combines solid and gas phases.After jet polishing,surface roughness(Sa)on the interior surface of grooves decreases from pristine 8.596μm to 0.701μm and 0.336μm via AAJ polishing and MPJ polishing,respectively,and Sa reduces 92%and 96%,correspondingly.Furthermore,a formula defining the relationship between linear energy density and unit defect volume has been developed.The optimized parameters in additive manufacturing are that linear energy density varies from 0.135 J mm^(-1)to 0.22 J mm^(-1).The unit area defect volume achieved via the optimized parameters decreases to 1/12 of that achieved via non-optimized ones.Computational fluid dynamics simulation results reveal that material is removed by shear stress,and the alumina abrasives experience multiple collisions with the defects on the heat pipe groove,resulting in uniform material removal.This is in good agreement with the experimental results.The novel proposed setups,approach,and findings provide new insights into manufacturing complex-structured components,polishing the small-grooved structure,and keeping it unbroken.
基金supported by the National Natural Science Foundation of China(11571132,12301542)the Natural Science Foundation of Hubei(2022CFB725)the Natural Science Foundation of Yichang(A23-2-027)。
文摘We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and possesses different transmission conditions.Using the variational method,we obtain the well posedness of the interior transmission problem,which plays an important role in the proof of the discreteness of eigenvalues.Then we achieve the existence of an infinite discrete set of transmission eigenvalues provided that n≡1,where a fourth order differential operator is applied.In the case of n■1,we show the discreteness of the transmission eigenvalues under restrictive assumptions by the analytic Fredholm theory and the T-coercive method.
文摘Understanding digital technology requires a shift in mindset that takes into account the broader implications of design,social dynamics,environmental factors,and cultural influences.Acknowledging the fact that technology is not confined to the virtual domain but rather has a tangible influence on our daily lives and the surrounding environment,the extensive integration and potential of digital technologies offer a distinctive prospect to fundamentally transform our shared comprehension of architecture.Digital technologies are revolutionizing design practices,manufacturing processes,and our engagement with and understanding of the built environment,by fostering the development of novel models that promote equity and inclusivity.The application of“digital technologies”can function as a methodology for examining and expressing the possible paths of emerging digital technologies.Extrapolate the expected impact of digital technologies on the design,development,and occupancy of the environment to achieve a more sustainable future in the long run.This paper will examine the potential connections and origins of digital technology concerning modularity,as well as the implications of modularity on forthcoming architectural developments in customization.
基金“Research on the Design Strategies of the Senior Community from the Perspective of Community Operation and Service Management,”University-level Research Projects in 2023(Project No.XdKY234732).
文摘Nowadays,the elderly have become an increasingly large group of people in China,but still many problems exist in their living space.This paper explores the physiological and psychological behavioral changes of the elderly,studies their living space requirements,and tries to put forward targeted design strategies in response.Therefore,making a better and more reasonable living space for the elderly as well as improving their living quality,finally helping the development of elderly-friendly design in China.
基金University-Level Teaching Reform Project“Research on Effective Models and Pathways for University-Enterprise Co-Construction of an Industry College Based on the School of Architecture and Urban Industry”(Q2310003)。
文摘To further enhance the effectiveness of talent cultivation for interior design in vocational colleges,it is necessary to vigorously promote the construction of an industry-education integration model.Through this model,the roles of both enterprises and schools can be leveraged to jointly facilitate the continuous improvement of students’professional abilities and practical skills,providing a steady stream of high-quality talents for the development of the interior design field.Therefore,this paper analyzes the current issues in interior design talent cultivation in vocational colleges from the perspective of industry-education integration and proposes corresponding improvement measures.
基金supported by the Natural Science Foundation of China under Grant No.61733004the Scientific Research Fund of the Hunan Provincial Education Department under Grand No.18A267.
文摘This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor(IPMSM)drive systems.The mathematical model of flux weakening(FW)control is established,and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve.Next,a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time.Then,an extended sliding mode disturbance observer(ESMDO)is designed to estimate the uncertainty of the system.Finally,compared with both the PI control and sliding mode control(SMC)by simulations and experiments with different working conditions,the method proposed has the merits of accelerating convergence,improving steady-state accuracy,and minimizing the current and torque pulsation.
文摘The Great Plague:The Diary of Alice Paynton,London 1665-1666 adopts the realistic painting style and direct writing to the painful experience,describes the situation of the Great Plague in London truly from the perspective of children,and breaks people’s cognitive expectation of children’s literature,the construction of children’s Gray inner world is completed behind the true description of the Great Plague in London with the true brushwork,which presents a different world of childlike innocence.Despite the importance of epidemics writing in literature,the child’s diary perspective of them is one of the least developed of Plague Narrative.Only when authenticity and the child’s grey interior are integrated will we reveal a true picture of society as it was.
文摘Based on the ideological and political requirements of interior design professional courses,exploring the integrated education path of professional plus innovation and entrepreneurship requires first expanding the ideological and political content of professional introductory courses,core courses,and expanded courses.Then,we will reshape the curriculum system based on the principle of connecting professional teaching and ideological and political courses,focusing on the realistic principle of talent needs,striving for student growth,adjusting the course content,optimizing the teaching model,and transforming teaching through in-and out-of-class practice and counterpoint guidance.
文摘For higher vocational colleges,skills competition is an important indicator of professional personnel training quality.In this paper,the architectural interior design professional skills competition in Chongqing Energy Vocational College is taken as an example,the many years of teaching and competition experience are taken into account,the problems existing in the cultivation of architectural interior design professionals in higher vocational colleges are analyzed,and corresponding solutions are proposed.
基金National Key R&D Program“Science and Technology Winter Olympics”(Grant Number:2020YFF0304900).
文摘Peking Union Medical College was founded in the late Qing Dynasty and the early Republic of China.Since then,society and politics have been rapidly changing,and its architectural aesthetics reflect the idea of advocating the West and inheriting tradition.Through research and actual investigation,this paper summarizes the current status of its building from two aspects,interior decoration art and interior decoration technology,analyzes the interior decoration characteristics of Peking Union Medical College Phase I Project,and records the archives of Peking Union Medical College’s decoration technology.
文摘“Internet Plus”thinking has been widely adopted in the teaching of interior design in colleges and universities,and its application has significant implications that cannot be disregarded.“Internet Plus”thinking not only realizes the innovation of interior design teaching but also significantly improves the level and quality of teaching.Through an analysis of the advantages of“Internet Plus”education platform and the current situation of higher vocational interior design teaching,effective strategies for higher vocational interior design teaching based on“Internet Plus”thinking are proposed in this paper in hope that this study will contribute to the efficient development of interior design teaching activities.
基金Natural Science Foundation of Fujian Province of China ( No.2009J01293)The Open Project of Brain-like Key Laboratory of Fujian Province of China (No. BLISSOS20101015)
文摘By using function one direction S-rough sets,the concept of F-interior hiding image is presented; the theorem of F-interior hiding and the recognition criteria of interior hiding are proposed; and the applications of F-interior hiding image are given. F-interior hiding image is a new application area of function S-rough sets,and function S-rough sets is a new theory and new tools for iconology research.
文摘Cluster warhead dispersing technique is analyzed with gas dynamic theory. It is seen that the front cover opening and two stage dispersing system is suitable for guided sub missiles whose number is not so large. The interior ballistic performances of this system are calculated with numerical calculation method. The performances such as the pressure in the pressure chambers and the velocity of the sub missiles are obtained in curve form.
文摘In this paper, an Improved Affine-Scaling Interior Point Algorithm for Linear Programming has been proposed. Computational results of selected practical problems affirming the proposed algorithm have been provided. The proposed algorithm is accurate, faster and therefore reduces the number of iterations required to obtain an optimal solution of a given Linear Programming problem as compared to the already existing Affine-Scaling Interior Point Algorithm. The algorithm can be very useful for development of faster software packages for solving linear programming problems using the interior-point methods.
文摘From the creation,materials,colors and technical artistic characteristics of exterior and exterior spatial decoration,the artistic value of ancient Huizhou folk houses were analyzed.
文摘Through analyzing the basic structure of ancient Huizhou vernacular dwellings and the spatial order of interior decoration,this study rethought profoundly about modern interior design and put forward the inheritance of traditional methods in interior decoration.
文摘Landscape plants play a role of decorating and beautifying the indoor environment.From the perspective of humanization,the functions and application patterns of landscape plants in the interior environmental design are analyzed in this study,and finally the application rules of landscape plants in the humanized interior environmental design are summarized.
基金supported by the Science and Technology Development Fund, Macao SAR (File No. 0005/2019/A1)the National Natural Science Foundation of China Grant No. 11761161001
文摘Measurements of Jupiter’s gravity field by Juno have been acquired with unprecedented precision, but uncertainties in the planet’s hydrogen–helium equation of state(EOS) and the hydrogen–helium phase separation have meant that differences remain in the interior model predictions. We deduce an empirical EOS from Juno gravity field observations in terms of the hydrostatic equation and then investigate the structure and composition of Jupiter by comparison of the empirical EOS with Jupiter’s adiabats obtained from the physical EOS. The deduced helium mass fraction suggests depletion of helium in the outermost atmosphere and helium concentration in the inner molecular hydrogen region, which is a signature of helium rain in Jupiter’s interior. The deduced envelope metallicity(the heavy-element mass fraction) is as high in the innermost envelope as 11–13 times the solar value. Such a high metallicity provides sharp support to the dilute core model with the heavy elements dissolved in hydrogen and expanded outward. No matter how the core mass is varied, the empirical EOS derived from the two-layer interior model generally suggests higher densities in the innermost envelope than does the best-fit Jupiter’s adiabat;this result is, again, a signature of dilute cores in Jupiter’s interior. Moreover, no matter the core mass,the empirical EOS is found to exhibit an inflexion point in the deep interior, around 10 Mbar, which can be explained as the combined effect of helium concentration in the upper part and dilute cores in the lower part.
文摘This article uses nonlinear dynamics analysis software AUTODYN-2D to establish an interior ballistic model of cen- tral blast tube cluster munitions dispersion. The interior ballistic process of the central blast tube duster munitions dispersion was simulated. The state of submunitions dispersion was obtained as interior ballistic conditions changed. The effect of shell stress groove on shell opening was discussed. The shell with stree groove is helpful for submunitions dispensing effectively and uniformly. The effect of liner material on submunitions dispersing was discussed. It can be found that foam liner can reduce the interior ballistic pressure, increase the pressure action time, reduce the acceleration of the submunitions and increase the sub- munitions dispersing velocity. These results provide some reference for the theory and experiment research of the central blast tube cluster munitions dispersion.
基金Supported by National Key R&D Program of China(Grant No.2016YFE0205200)National Natural Science Foundation of China(Grant No.U1834201)
文摘Noise is one of the key issues in the operation of high-speed railways, with sound source localisation and its transfer path as the two major aspects. This study investigates both the exterior and interior sound source distribution of a high-speed train and presents a method for performing the contribution analysis of airborne sound with regard to the interior noise. First, both exterior and interior sound source locations of the high-speed train are identified through in-situ measurements. Second, the sound source contribution for di erent regions of the train and the relationships between the exterior and interior noises are analysed. Third, a method for conducting the contribution analysis of airborne sound with regard to the interior noise of the high-speed train is described. Lastly, a case study on the sidewall area is carried out, and the contribution of airborne sound to the interior noise of this area is obtained. The results show that, when the high-speed train runs at 310 km/h, dominant exterior sound sources are located in the bogie and pantograph regions, while main interior sound sources are located at the sidewall and roof. The interior noise, the bogie area noise and the sound source at the middle of the coach exhibit very similar rates of increase with increasing train speed. For the selected sidewall area, structure-borne sound dominates in most of the 1/3 octave bands.