This paper studies in detail the interaction of two edge dislocations nested in a Gaussian beam propagating in free space. It shows that in free-space propagation the edge dislocations are unstable and vanish, and two...This paper studies in detail the interaction of two edge dislocations nested in a Gaussian beam propagating in free space. It shows that in free-space propagation the edge dislocations are unstable and vanish, and two noncanonical vortices with opposite topological charge take place when off-axis distances cl and c2 of two edge dislocations are nonzero, and the condition k2w08＋ 32c1c2（w02- 2C1C2）Z2 〉 0 is fulfilled （k-wave number, w0-waist width）. A noncanonical vortex appears when one off-axis distance is zero. However, one edge dislocation is stable when two edge dislocations are perpendicular and one off-axis distance is zero. Two perpendicular edge dislocations both with zero off-axis distance are also stable. The analytical results are illustrated by numerical examples.展开更多
Objective To assess the independent and combined effects of air pollutants,meteorological factors,and greenspace exposure on new tuberculosis(TB)cases.Methods TB case data from Shanghai(2013–2018)were obtained from t...Objective To assess the independent and combined effects of air pollutants,meteorological factors,and greenspace exposure on new tuberculosis(TB)cases.Methods TB case data from Shanghai(2013–2018)were obtained from the Shanghai Center for Disease Control and Prevention.Environmental data on air pollutants,meteorological variables,and greenspace exposure were obtained from the National Tibetan Plateau Data Center.We employed a distributed-lag nonlinear model to assess the effects of these environmental factors on TB cases.Results Increased TB risk was linked to PM_(2.5),PM_(10),and rainfall,whereas NO_(2),SO_(2),and air pressure were associated with a reduced risk.Specifically,the strongest cumulative effects occurred at various lags:PM_(2.5)(RR=1.166,95%CI:1.026–1.325)at 0–19 weeks;PM_(10)(RR=1.167,95%CI:1.028–1.324)at 0–18 weeks;NO_(2)(RR=0.968,95%CI:0.938–0.999)at 0–1 weeks;SO_(2)(RR=0.945,95%CI:0.894–0.999)at 0–2 weeks;air pressure(RR=0.604,95%CI:0.447–0.816)at 0–8 weeks;and rainfall(RR=1.404,95%CI:1.076–1.833)at 0–22 weeks.Green space exposure did not significantly impact TB cases.Additionally,low temperatures amplified the effect of PM_(2.5)on TB.Conclusion Exposure to PM_(2.5),PM_(10),and rainfall increased the risk of TB,highlighting the need to address air pollutants for the prevention of TB in Shanghai.展开更多
The dynamic soil-tunnel interaction is studied by indirect boundary element method （IBEM）, using the model of a rigid tunnel in layered half-space, which is simplified to a single soil layer on elastic bedrock, subj...The dynamic soil-tunnel interaction is studied by indirect boundary element method （IBEM）, using the model of a rigid tunnel in layered half-space, which is simplified to a single soil layer on elastic bedrock, subjected to incident plane SH waves. The accuracy of the results is verified through comparison with the analytical solution. It is shown that soil-tunnel interaction in layered half-space is larger than that in homogeneous half-space and this interaction mechanism is essentially different from that of soil-foundation-superstructure interaction.展开更多
The interaction of wave-particles and wave-wave in the space plasmas are essentially non-linear or non-Gaussian processes. Using the higher-order statistical analyses methods (higher-order moments and bi-tri correlati...The interaction of wave-particles and wave-wave in the space plasmas are essentially non-linear or non-Gaussian processes. Using the higher-order statistical analyses methods (higher-order moments and bi-tri correlation or bi-tri spectrum), its physical properties can be described. The question addressed in this paper is that of the usefulness of higher-order statistical analysis for identification of the wave-particles interaction in space plasmas. The signals handled are from the ARCAD-3 ISOPROBE experiment on ELF frequency range, then strong electrostatic turbulence and electron density irregularities. Second and third order statistical analyses are applied: first, on time series associated with each type of measurement, then, on the two types. All results are presented for one typical case. Correlation functions estimated over the corresponding time intervals point out the existence of a, non-linear interaction between these fluctuations and electrostatic filed.展开更多
The through-space and through-bond interactions of molecular orbitals in [2,2] paracyclophane are studied by the approved MS-X. method with overlapping atomic-sphere. The calculation results show the through-space in...The through-space and through-bond interactions of molecular orbitals in [2,2] paracyclophane are studied by the approved MS-X. method with overlapping atomic-sphere. The calculation results show the through-space interactions are exponential flareout with increasing of the distance of two orbitals, and.both through-space interactions and through-bond interactions are sizable but those two interactions oppose each other causing the net splitting to be small. Transition-state procedure was used to calculate ionization potentials, the results are in agreement with the PE-spectra.展开更多
The dynamic soil-tunnel interaction is studied by the model of a rigid tunnel embedded in layered half-space, which is simplified as a single soil layer on elastic bedrock to the excitation of P- and SV-waves. The ind...The dynamic soil-tunnel interaction is studied by the model of a rigid tunnel embedded in layered half-space, which is simplified as a single soil layer on elastic bedrock to the excitation of P- and SV-waves. The indirect boundary element method is used, combined with the Green＇ s function of distributed loads acting on inclined lines. It is shown that the dynamic characteristics of soil-tunnel interaction in layered half-space are different much from that in homoge- neous half-space, and that the mechanism of soil-tunnel interaction is also different much from that of soil-founda- tion-superstructure interaction. For oblique incidence, the tunnel response for in-plane incident SV-waves is com- pletely different from that for incident SH-waves, while the tunnel response for vertically incident SV-wave is very similar to that of vertically incident SH-wave.展开更多
The through--space and through--bond interactions in 1, 5 -- Cyclooctadiyne are studied. It is shown, with the assistance of improved MS--X_α method, that the through- space interactions decrease with the distance of...The through--space and through--bond interactions in 1, 5 -- Cyclooctadiyne are studied. It is shown, with the assistance of improved MS--X_α method, that the through- space interactions decrease with the distance of the orbitals, and both through--space and through--bond interactions of 1, 5- Cyclooctadiyne are sizable but those two interactions oppose each other causing the net splitting to be small for π_z orbital. The calculated ionization potentials are in good agreement with the experiment of photoelectron spectra.展开更多
The issues of analyzing the cultural differences in architecture, and the interaction between culture and space have gained importance in many respects both in practice and in education. ＂Culture＂ and conservation o...The issues of analyzing the cultural differences in architecture, and the interaction between culture and space have gained importance in many respects both in practice and in education. ＂Culture＂ and conservation of the ＂cultural heritage＂ have a place in the conditions for the ＂architectural education＂ put forward by the UNESCO （The United Nations Educational, Scientific and Cultural Organization）/UIA （International Union of Architects） Council during the 2002 meeting in Berlin. For this purpose, cultural, social, urban, environmental and architectural values and issues of architectural heritage were defined as specific subjects that should be considered in the preparation of the curriculum to build up a sense of responsibility. From this point of view, this paper aims to propose an educational process for dealing with the sense of cultural heritage and its survival in the modern world, and shares the products of the work carried out at the Project 4 Studio at Faculty of Fine Arts, Department of Interior Architecture, Yeditepe University, as the studio training is the main component of architectural education. The main issue of the paper is to present some examples of the student projects and to consider the importance of design studio, which can gain knowledge about cultural and architectural heritage and develop students＇ skills to adopt and be respectful to traditional values.展开更多
In this paper we study the interaction of strong and weak singularities for hyperbolic system of conservation laws in multidimensional space. Under the assumption of transversal intersect of the shock front with the b...In this paper we study the interaction of strong and weak singularities for hyperbolic system of conservation laws in multidimensional space. Under the assumption of transversal intersect of the shock front with the bicharacteristics bearing weak singularities we proved a theorem on regularity propagation across the shock front.展开更多
The interaction between the machining process and the machine tool （IMPMT） plays an important role on high precision components manufacturing. However, most researches are focused on the machining process or the mac...The interaction between the machining process and the machine tool （IMPMT） plays an important role on high precision components manufacturing. However, most researches are focused on the machining process or the machine tool separately, and the interaction between them has been always overlooked. In this paper, a novel simplified method is proposed to realize the simulation of IMPMT by combining use the finite element method and state space method. In this method, the transfer function of the machine tool is built as a small state space. The small state space is obtained from the complicated finite element model of the whole machine tool. Furthermore, the control system of the machine tool is integrated with the transfer function of the machine tool to generate the cutting trajectory. Then, the tool tip response under the cutting force is used to predict the machined surface. Finally, a case study is carried out for a fly-cutting machining process, the dynamic response analysis of an ultra-precision fly-cutting machine tool and the machined surface verifies the effectiveness of this method. This research proposes a simplified method to study the IMPMT, the relationships between the machining process and the machine tool are established and the surface generation is obtained.展开更多
In addition to the hexagonal crystals of class 6 mm, many piezoelectric materials （e.g., BaTiO3）, piezomagnetic materials （e.g., CoFe2O4）, and multiferroic com-posite materials （e.g., BaTiO3-CoFe2O4 composites）...In addition to the hexagonal crystals of class 6 mm, many piezoelectric materials （e.g., BaTiO3）, piezomagnetic materials （e.g., CoFe2O4）, and multiferroic com-posite materials （e.g., BaTiO3-CoFe2O4 composites） also exhibit symmetry of transverse isotropy after poling, with the isotropic plane perpendicular to the poling direction. In this paper, simple and elegant line-integral expressions are derived for extended displace-ments, extended stresses, self-energy, and interaction energy of arbitrarily shaped, three-dimensional （3D） dislocation loops with a constant extended Burgers vector in trans-versely isotropic magneto-electro-elastic （MEE） bimaterials （i.e., joined half-spaces）. The derived solutions can also be simply reduced to those expressions for piezoelectric, piezo-magnetic, or purely elastic materials. Several numerical examples are given to show both the multi-field coupling effect and the interface/surface effect in transversely isotropic MEE materials.展开更多
A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic performance.In this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid ...A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic performance.In this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid dynamics(CFD) approach, in which the unsteady, noncompressible Reynolds Averaged Navier-Stokes(RANS) method is used. The main focus of the study is to analyze the tower shadow effect on the aerodynamic performance of the wind turbine under different inlet flow conditions. Subsequently, the finite element model is established by considering fluid/structure interactions to study the structural stress, displacement, strain distributions and flow field information of the structure under the uniform wind speed. Finally, the fluid-structure interaction model is established by considering turbulent wind and the tower shadow effect. The variation rules of the dynamic response of the one-way and two-way fluid-structure interaction(FSI) models under different wind speeds are analyzed, and the numerical calculation results are compared with those of the centralized mass model. The results show that the tower shadow effect and structural deformation are the main factors affecting the aerodynamic load fluctuation of the wind turbine, which in turn affects the aerodynamic performance and structural stability of the blades. The structural dynamic response of the coupled model shows significant similarity, while the structural displacement response of the former exhibits less fluctuation compared with the conventional centralized mass model. The one-way fluid-structure interaction(FSI)model shows a higher frequency of stress-strain and displacement oscillations on the blade compared with the two-way FSI model.展开更多
The elastic stress distribution and the variation of the elastic energy with spacing between two inclusions of arbitrary sizes in an infinite isotropic cylindrical rod are obtained by an analytical approach and the ph...The elastic stress distribution and the variation of the elastic energy with spacing between two inclusions of arbitrary sizes in an infinite isotropic cylindrical rod are obtained by an analytical approach and the phase field microelasticity(PFM)simulation.The results show a near-attraction and far-repulsion elastic interaction between two inclusions with hydrostatic dilatation.The critical spacing,at which the interaction changes from attraction to repulsion,is on the order of the radius of the rod,dependent on the length and Poisson’s ratio of inclusions.Furthermore,the elastic energy calculations and PFM simulation results indicate that applying the local radial stress on the rod surface can modulate the elastic interaction between inclusions and adjust the periodicity of the superlattice nanowire structure.This can provide some guidelines for the tunable construction of superlattice nanowire structures.展开更多
In this paper we deal with a nonlinear interaction problem between an incompressible viscous fluid and a nonlinear thermoelastic plate.The nonlinearity in the plate equation corresponds to nonlinear elastic force in v...In this paper we deal with a nonlinear interaction problem between an incompressible viscous fluid and a nonlinear thermoelastic plate.The nonlinearity in the plate equation corresponds to nonlinear elastic force in various physically relevant semilinear and quasilinear plate models.We prove the existence of a weak solution for this problem by constructing a hybrid approximation scheme that,via operator splitting,decouples the system into two sub-problems,one piece-wise stationary for the fluid and one time-continuous and in a finite basis for the structure.To prove the convergence of the approximate quasilinear elastic force,we develop a compensated compactness method that relies on the maximal monotonicity property of this nonlinear function.展开更多
Shock wave/boundary layer interaction in a 24°turning angle of the compression ramp at Mach number 2.9 controlled by steady microjet is investigated using direct numerical simulation.Three different jet spacings ...Shock wave/boundary layer interaction in a 24°turning angle of the compression ramp at Mach number 2.9 controlled by steady microjet is investigated using direct numerical simulation.Three different jet spacings which are termed as sparse,moderate and dense are considered,and the induced vortex system and shock structures are compared.A moderate jet spacing configuration is found to generate counter-rotating vortex pairs that transport high-momentum fluid towards the vicinity of wall and strengthen the boundary layer to resist separation,reducing the separation region.The dense jet spacing configuration creates a larger momentum deficit region,reducing the friction downstream of the corner.Analysis of pressure and pressure gradient reveals that dense jet spacing configuration reduces the intensity of separation shock.The impact of varying jet spacings on the turbulent kinetic energy transport mechanism is also investigated by decomposing the budget terms in the transport equation.Furthermore,the spectral characteristics of the separation region are studied using power spectral density and dynamic mode decomposition methods,revealing that moderate jet spacing configuration suppresses low-frequency fluctuations in the separation region.展开更多
Richard Wright was one of America’s greatest black writers andone of the first African American writers to achieve liter⁃ary fame and fortune.Black Boy(1945)ishis autobiographical novel,consisting of Southern Nightan...Richard Wright was one of America’s greatest black writers andone of the first African American writers to achieve liter⁃ary fame and fortune.Black Boy(1945)ishis autobiographical novel,consisting of Southern Nightand Fear and Honor,which tells the story of the protagonist's experiences in five different environments and his great changes.This thesis explores the interaction between space and characters.It finds that,on the one hand,space provides a place for the characters to move around,which af⁃fects them physically and psychologically and shapes their personality.On the other hand,characters make resistances against space,and their behavior and living conditions further reflect the characteristics of each space.Through research,the protagonist grows under the change of spaces,and such growth also highlights the characteristics of different spaces.The interaction between the two carries all the transitions between the stories.展开更多
The study deals with physical modeling of a typical building frame resting on a pile group embedded in cohesive soil mass using complete three-dimensional finite element analysis. The elements of the superstructure fr...The study deals with physical modeling of a typical building frame resting on a pile group embedded in cohesive soil mass using complete three-dimensional finite element analysis. The elements of the superstructure frame and that of the pile foundation are discretized using twenty node isoparametric continuum elements. The interface between the pile and pile cap is idealized using sixteen node isoparametric surface elements. The more improved finite element mesh is used for modeling soil element as compared to the one used in the study reported in the literature. The soil elements are discretized using eight node, nine node and twelve node continuum elements. Both the elements of superstructure and substructure (i.e., foundation) including soil are assumed to remain in elastic state at all the time. The interaction analysis is carried out using sub-structure approach to attempt a parametric study. The effect of the parameter such as spacing between the piles in a group and diameter of pile is evaluated on the response of superstructure. The response includes the displacement at the top of the frame. The effect of the soil-structure interaction is observed to be significant for the type of foundation and soil considered in the present study.展开更多
This paper focuses on the application of interactive media technology in the visual interpretation of traditional graphic urban public spaces in China.Case studies and practical exploration show that interactive media...This paper focuses on the application of interactive media technology in the visual interpretation of traditional graphic urban public spaces in China.Case studies and practical exploration show that interactive media technologies such as projection mapping,interactive devices,virtual reality technology,etc.,have realized the diversity of traditional graphics display forms in urban public space.The rich interactive experience design enhances the sense of participation and experience of urban citizens and tourists and promotes the visual culture transmission of traditional Chinese graphics.The future urban public space exhibition is destined to continue to deepen the integration of technology and graphics,promote the visual communication of traditional Chinese graphics visual interpretation in urban public space,and promote sustainable innovation in cultural output in urban public space exhibitions around the world.展开更多
Safe and just operating spaces(SJOS)are influenced by complex cross-scale interactions and cascading effects spanning global,regional,and local landscape scales.However,existing SJOS research has often focused on sing...Safe and just operating spaces(SJOS)are influenced by complex cross-scale interactions and cascading effects spanning global,regional,and local landscape scales.However,existing SJOS research has often focused on single-scale assessments,overlooking the impacts of multiscale interactions and within-region heterogeneity on urban SJOS.To address this gap,we developed a cross-scale framework for assessing urban SJOS,explicitly incorporating top-down influences from upper-level constraints and bottom-up effects from lower-level heterogeneity.This approach was applied to China's five major metropolises to examine the states and cross-scale dynamics influencing urban SJOS between 1990 and 2020.Our findings reveal that the SJOS of China's metropolises were primarily influenced by factors at national and local landscape scales,with weaker influences from the global and continental scales.A persistent trade-off between social justice and environmental safety was identified across spatiotemporal scales.For instance,Chongqing in southwestern China lagged behind the eastern four metropolises in social performance but exhibited stronger environmental safety due to its extensive natural landscapes,which mitigated the anthropogenic impacts of urban centers.Regional issues,such as the overshoot of PM_(2.5)and ecological footprints(EF),were primarily driven by the bottom-up accumulation of localized pressures,while the overshoot of CO_(2)was attributed to national policy constraints and the universal exceedance of safe thresholds across scales.Addressing urban sustainability requires avoiding adverse cascading effects from other levels by emphasizing landscape heterogeneity within metropolises and fostering coordinated collaboration across scales,particularly at the regional landscape and national levels.展开更多
We have examined an isotropic and homogeneous cosmological model in f(R,T^(φ))gravity,where R represents the Ricci scalar and T^(φ)exhibits the energy momentum tensor's trace.We examine the stability criteria by...We have examined an isotropic and homogeneous cosmological model in f(R,T^(φ))gravity,where R represents the Ricci scalar and T^(φ)exhibits the energy momentum tensor's trace.We examine the stability criteria by performing the dynamical system analysis for our model f(R,T^(φ))=R+2(a T^(φ)+b),where a and b are the constants.We derive a set of autonomous equations and find their solutions by assuming a flat potential V0.We assess the equilibrium points from these equations and find the eigenvalues.We analyze the physical interpretation of the phase space for this system.We obtain three stable equilibrium points.We also examine the interaction between the scalar field and dark energy,represented by Q=ψH_(ρde)and determine the equilibrium points for this interaction.We identify four stable equilibrium points for this interaction.We calculate the values of the physical parameters for both scenarios at each equilibrium point,indicating the Universe's accelerated expansion.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.10874125)
文摘This paper studies in detail the interaction of two edge dislocations nested in a Gaussian beam propagating in free space. It shows that in free-space propagation the edge dislocations are unstable and vanish, and two noncanonical vortices with opposite topological charge take place when off-axis distances cl and c2 of two edge dislocations are nonzero, and the condition k2w08＋ 32c1c2（w02- 2C1C2）Z2 〉 0 is fulfilled （k-wave number, w0-waist width）. A noncanonical vortex appears when one off-axis distance is zero. However, one edge dislocation is stable when two edge dislocations are perpendicular and one off-axis distance is zero. Two perpendicular edge dislocations both with zero off-axis distance are also stable. The analytical results are illustrated by numerical examples.
基金supported by the National Key Research and Development Program of China[2023YFC2307305]Shenzhen Medical Research Fund[B2303003]+3 种基金the Zhujiang Innovation and Entrepreneurship Talents Program[2021ZT09Y544]the Shenzhen Science and Technology Program[ZDSYS20230626091203007]Shanghai CDC(Shanghai three-year(2023–2025)action plan to strengthen the public health system[GWVI–11.1–05])Top Young Talents in Shanghai。
文摘Objective To assess the independent and combined effects of air pollutants,meteorological factors,and greenspace exposure on new tuberculosis(TB)cases.Methods TB case data from Shanghai(2013–2018)were obtained from the Shanghai Center for Disease Control and Prevention.Environmental data on air pollutants,meteorological variables,and greenspace exposure were obtained from the National Tibetan Plateau Data Center.We employed a distributed-lag nonlinear model to assess the effects of these environmental factors on TB cases.Results Increased TB risk was linked to PM_(2.5),PM_(10),and rainfall,whereas NO_(2),SO_(2),and air pressure were associated with a reduced risk.Specifically,the strongest cumulative effects occurred at various lags:PM_(2.5)(RR=1.166,95%CI:1.026–1.325)at 0–19 weeks;PM_(10)(RR=1.167,95%CI:1.028–1.324)at 0–18 weeks;NO_(2)(RR=0.968,95%CI:0.938–0.999)at 0–1 weeks;SO_(2)(RR=0.945,95%CI:0.894–0.999)at 0–2 weeks;air pressure(RR=0.604,95%CI:0.447–0.816)at 0–8 weeks;and rainfall(RR=1.404,95%CI:1.076–1.833)at 0–22 weeks.Green space exposure did not significantly impact TB cases.Additionally,low temperatures amplified the effect of PM_(2.5)on TB.Conclusion Exposure to PM_(2.5),PM_(10),and rainfall increased the risk of TB,highlighting the need to address air pollutants for the prevention of TB in Shanghai.
基金National Natural Science Foundation of China under Grant 51378384Key Project of Natural Science Foundation of Tianjin Municipality under Grant 12JCZDJC29000
文摘The dynamic soil-tunnel interaction is studied by indirect boundary element method （IBEM）, using the model of a rigid tunnel in layered half-space, which is simplified to a single soil layer on elastic bedrock, subjected to incident plane SH waves. The accuracy of the results is verified through comparison with the analytical solution. It is shown that soil-tunnel interaction in layered half-space is larger than that in homogeneous half-space and this interaction mechanism is essentially different from that of soil-foundation-superstructure interaction.
文摘The interaction of wave-particles and wave-wave in the space plasmas are essentially non-linear or non-Gaussian processes. Using the higher-order statistical analyses methods (higher-order moments and bi-tri correlation or bi-tri spectrum), its physical properties can be described. The question addressed in this paper is that of the usefulness of higher-order statistical analysis for identification of the wave-particles interaction in space plasmas. The signals handled are from the ARCAD-3 ISOPROBE experiment on ELF frequency range, then strong electrostatic turbulence and electron density irregularities. Second and third order statistical analyses are applied: first, on time series associated with each type of measurement, then, on the two types. All results are presented for one typical case. Correlation functions estimated over the corresponding time intervals point out the existence of a, non-linear interaction between these fluctuations and electrostatic filed.
文摘The through-space and through-bond interactions of molecular orbitals in [2,2] paracyclophane are studied by the approved MS-X. method with overlapping atomic-sphere. The calculation results show the through-space interactions are exponential flareout with increasing of the distance of two orbitals, and.both through-space interactions and through-bond interactions are sizable but those two interactions oppose each other causing the net splitting to be small. Transition-state procedure was used to calculate ionization potentials, the results are in agreement with the PE-spectra.
基金supported by the National Natural Science Foundation of China(No.51378384)the Key Project of Natural Science Foundation of Tianjin Municipality(No. 12JCZDJC29000)
文摘The dynamic soil-tunnel interaction is studied by the model of a rigid tunnel embedded in layered half-space, which is simplified as a single soil layer on elastic bedrock to the excitation of P- and SV-waves. The indirect boundary element method is used, combined with the Green＇ s function of distributed loads acting on inclined lines. It is shown that the dynamic characteristics of soil-tunnel interaction in layered half-space are different much from that in homoge- neous half-space, and that the mechanism of soil-tunnel interaction is also different much from that of soil-founda- tion-superstructure interaction. For oblique incidence, the tunnel response for in-plane incident SV-waves is com- pletely different from that for incident SH-waves, while the tunnel response for vertically incident SV-wave is very similar to that of vertically incident SH-wave.
文摘The through--space and through--bond interactions in 1, 5 -- Cyclooctadiyne are studied. It is shown, with the assistance of improved MS--X_α method, that the through- space interactions decrease with the distance of the orbitals, and both through--space and through--bond interactions of 1, 5- Cyclooctadiyne are sizable but those two interactions oppose each other causing the net splitting to be small for π_z orbital. The calculated ionization potentials are in good agreement with the experiment of photoelectron spectra.
文摘The issues of analyzing the cultural differences in architecture, and the interaction between culture and space have gained importance in many respects both in practice and in education. ＂Culture＂ and conservation of the ＂cultural heritage＂ have a place in the conditions for the ＂architectural education＂ put forward by the UNESCO （The United Nations Educational, Scientific and Cultural Organization）/UIA （International Union of Architects） Council during the 2002 meeting in Berlin. For this purpose, cultural, social, urban, environmental and architectural values and issues of architectural heritage were defined as specific subjects that should be considered in the preparation of the curriculum to build up a sense of responsibility. From this point of view, this paper aims to propose an educational process for dealing with the sense of cultural heritage and its survival in the modern world, and shares the products of the work carried out at the Project 4 Studio at Faculty of Fine Arts, Department of Interior Architecture, Yeditepe University, as the studio training is the main component of architectural education. The main issue of the paper is to present some examples of the student projects and to consider the importance of design studio, which can gain knowledge about cultural and architectural heritage and develop students＇ skills to adopt and be respectful to traditional values.
文摘In this paper we study the interaction of strong and weak singularities for hyperbolic system of conservation laws in multidimensional space. Under the assumption of transversal intersect of the shock front with the bicharacteristics bearing weak singularities we proved a theorem on regularity propagation across the shock front.
基金Supported by National Natural Science Foundation of China(Grant No.51505107)Natural Scientific Research Innovation Foundation in Harbin Institute of Technology of China(Grant No.HIT.NSRIF.2017029)
文摘The interaction between the machining process and the machine tool （IMPMT） plays an important role on high precision components manufacturing. However, most researches are focused on the machining process or the machine tool separately, and the interaction between them has been always overlooked. In this paper, a novel simplified method is proposed to realize the simulation of IMPMT by combining use the finite element method and state space method. In this method, the transfer function of the machine tool is built as a small state space. The small state space is obtained from the complicated finite element model of the whole machine tool. Furthermore, the control system of the machine tool is integrated with the transfer function of the machine tool to generate the cutting trajectory. Then, the tool tip response under the cutting force is used to predict the machined surface. Finally, a case study is carried out for a fly-cutting machining process, the dynamic response analysis of an ultra-precision fly-cutting machine tool and the machined surface verifies the effectiveness of this method. This research proposes a simplified method to study the IMPMT, the relationships between the machining process and the machine tool are established and the surface generation is obtained.
基金Project supported by the National Project of Scientific and Technical Supporting Programs Funded by Ministry of Science&Technology of China(No.2009BAG12A01-A03-2)the National Natural Science Foundation of China(Nos.10972196,11090333,11172273,and 11321202)
文摘In addition to the hexagonal crystals of class 6 mm, many piezoelectric materials （e.g., BaTiO3）, piezomagnetic materials （e.g., CoFe2O4）, and multiferroic com-posite materials （e.g., BaTiO3-CoFe2O4 composites） also exhibit symmetry of transverse isotropy after poling, with the isotropic plane perpendicular to the poling direction. In this paper, simple and elegant line-integral expressions are derived for extended displace-ments, extended stresses, self-energy, and interaction energy of arbitrarily shaped, three-dimensional （3D） dislocation loops with a constant extended Burgers vector in trans-versely isotropic magneto-electro-elastic （MEE） bimaterials （i.e., joined half-spaces）. The derived solutions can also be simply reduced to those expressions for piezoelectric, piezo-magnetic, or purely elastic materials. Several numerical examples are given to show both the multi-field coupling effect and the interface/surface effect in transversely isotropic MEE materials.
基金supported by the National Natural Science Foundation of China(Grant No.52078010)Beijing Natural Science Foundation(Grant No.JQ19029).
文摘A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic performance.In this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid dynamics(CFD) approach, in which the unsteady, noncompressible Reynolds Averaged Navier-Stokes(RANS) method is used. The main focus of the study is to analyze the tower shadow effect on the aerodynamic performance of the wind turbine under different inlet flow conditions. Subsequently, the finite element model is established by considering fluid/structure interactions to study the structural stress, displacement, strain distributions and flow field information of the structure under the uniform wind speed. Finally, the fluid-structure interaction model is established by considering turbulent wind and the tower shadow effect. The variation rules of the dynamic response of the one-way and two-way fluid-structure interaction(FSI) models under different wind speeds are analyzed, and the numerical calculation results are compared with those of the centralized mass model. The results show that the tower shadow effect and structural deformation are the main factors affecting the aerodynamic load fluctuation of the wind turbine, which in turn affects the aerodynamic performance and structural stability of the blades. The structural dynamic response of the coupled model shows significant similarity, while the structural displacement response of the former exhibits less fluctuation compared with the conventional centralized mass model. The one-way fluid-structure interaction(FSI)model shows a higher frequency of stress-strain and displacement oscillations on the blade compared with the two-way FSI model.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB22040502)the National Natural Science Foundation of China(No.11672285)and the Fundamental Research Funds for the Central Universities of China(No.WK2090050043)。
文摘The elastic stress distribution and the variation of the elastic energy with spacing between two inclusions of arbitrary sizes in an infinite isotropic cylindrical rod are obtained by an analytical approach and the phase field microelasticity(PFM)simulation.The results show a near-attraction and far-repulsion elastic interaction between two inclusions with hydrostatic dilatation.The critical spacing,at which the interaction changes from attraction to repulsion,is on the order of the radius of the rod,dependent on the length and Poisson’s ratio of inclusions.Furthermore,the elastic energy calculations and PFM simulation results indicate that applying the local radial stress on the rod surface can modulate the elastic interaction between inclusions and adjust the periodicity of the superlattice nanowire structure.This can provide some guidelines for the tunable construction of superlattice nanowire structures.
基金partially supported by National Natural Science Foundation of China(11631008)。
文摘In this paper we deal with a nonlinear interaction problem between an incompressible viscous fluid and a nonlinear thermoelastic plate.The nonlinearity in the plate equation corresponds to nonlinear elastic force in various physically relevant semilinear and quasilinear plate models.We prove the existence of a weak solution for this problem by constructing a hybrid approximation scheme that,via operator splitting,decouples the system into two sub-problems,one piece-wise stationary for the fluid and one time-continuous and in a finite basis for the structure.To prove the convergence of the approximate quasilinear elastic force,we develop a compensated compactness method that relies on the maximal monotonicity property of this nonlinear function.
基金Supported by the National Natural Science Foundation of China(Nos.11972064,92052104)the Key Laboratory of Computational Aerodynamics,AVIC Aerodynamics Research Institute,China(No.YL2022XFX0405)the Fundamental Research Funds for the Central Universities,China.
文摘Shock wave/boundary layer interaction in a 24°turning angle of the compression ramp at Mach number 2.9 controlled by steady microjet is investigated using direct numerical simulation.Three different jet spacings which are termed as sparse,moderate and dense are considered,and the induced vortex system and shock structures are compared.A moderate jet spacing configuration is found to generate counter-rotating vortex pairs that transport high-momentum fluid towards the vicinity of wall and strengthen the boundary layer to resist separation,reducing the separation region.The dense jet spacing configuration creates a larger momentum deficit region,reducing the friction downstream of the corner.Analysis of pressure and pressure gradient reveals that dense jet spacing configuration reduces the intensity of separation shock.The impact of varying jet spacings on the turbulent kinetic energy transport mechanism is also investigated by decomposing the budget terms in the transport equation.Furthermore,the spectral characteristics of the separation region are studied using power spectral density and dynamic mode decomposition methods,revealing that moderate jet spacing configuration suppresses low-frequency fluctuations in the separation region.
文摘Richard Wright was one of America’s greatest black writers andone of the first African American writers to achieve liter⁃ary fame and fortune.Black Boy(1945)ishis autobiographical novel,consisting of Southern Nightand Fear and Honor,which tells the story of the protagonist's experiences in five different environments and his great changes.This thesis explores the interaction between space and characters.It finds that,on the one hand,space provides a place for the characters to move around,which af⁃fects them physically and psychologically and shapes their personality.On the other hand,characters make resistances against space,and their behavior and living conditions further reflect the characteristics of each space.Through research,the protagonist grows under the change of spaces,and such growth also highlights the characteristics of different spaces.The interaction between the two carries all the transitions between the stories.
文摘The study deals with physical modeling of a typical building frame resting on a pile group embedded in cohesive soil mass using complete three-dimensional finite element analysis. The elements of the superstructure frame and that of the pile foundation are discretized using twenty node isoparametric continuum elements. The interface between the pile and pile cap is idealized using sixteen node isoparametric surface elements. The more improved finite element mesh is used for modeling soil element as compared to the one used in the study reported in the literature. The soil elements are discretized using eight node, nine node and twelve node continuum elements. Both the elements of superstructure and substructure (i.e., foundation) including soil are assumed to remain in elastic state at all the time. The interaction analysis is carried out using sub-structure approach to attempt a parametric study. The effect of the parameter such as spacing between the piles in a group and diameter of pile is evaluated on the response of superstructure. The response includes the displacement at the top of the frame. The effect of the soil-structure interaction is observed to be significant for the type of foundation and soil considered in the present study.
文摘This paper focuses on the application of interactive media technology in the visual interpretation of traditional graphic urban public spaces in China.Case studies and practical exploration show that interactive media technologies such as projection mapping,interactive devices,virtual reality technology,etc.,have realized the diversity of traditional graphics display forms in urban public space.The rich interactive experience design enhances the sense of participation and experience of urban citizens and tourists and promotes the visual culture transmission of traditional Chinese graphics.The future urban public space exhibition is destined to continue to deepen the integration of technology and graphics,promote the visual communication of traditional Chinese graphics visual interpretation in urban public space,and promote sustainable innovation in cultural output in urban public space exhibitions around the world.
基金supported by the National Natural Science Foundation of China(Grant No.42101296)the Natural Science Foundation of Chongqing(Grant No.CSTB2023NSCQ-MSX0041)Chongqing Municipal Training Program of Innovation and Entrepreneurship Project(Grants No.S202410635155 and X202410635116)。
文摘Safe and just operating spaces(SJOS)are influenced by complex cross-scale interactions and cascading effects spanning global,regional,and local landscape scales.However,existing SJOS research has often focused on single-scale assessments,overlooking the impacts of multiscale interactions and within-region heterogeneity on urban SJOS.To address this gap,we developed a cross-scale framework for assessing urban SJOS,explicitly incorporating top-down influences from upper-level constraints and bottom-up effects from lower-level heterogeneity.This approach was applied to China's five major metropolises to examine the states and cross-scale dynamics influencing urban SJOS between 1990 and 2020.Our findings reveal that the SJOS of China's metropolises were primarily influenced by factors at national and local landscape scales,with weaker influences from the global and continental scales.A persistent trade-off between social justice and environmental safety was identified across spatiotemporal scales.For instance,Chongqing in southwestern China lagged behind the eastern four metropolises in social performance but exhibited stronger environmental safety due to its extensive natural landscapes,which mitigated the anthropogenic impacts of urban centers.Regional issues,such as the overshoot of PM_(2.5)and ecological footprints(EF),were primarily driven by the bottom-up accumulation of localized pressures,while the overshoot of CO_(2)was attributed to national policy constraints and the universal exceedance of safe thresholds across scales.Addressing urban sustainability requires avoiding adverse cascading effects from other levels by emphasizing landscape heterogeneity within metropolises and fostering coordinated collaboration across scales,particularly at the regional landscape and national levels.
基金funded by Researchers Supporting Project No.RSPD2025R733,King Saud University,Riyadh,Saudi Arabia。
文摘We have examined an isotropic and homogeneous cosmological model in f(R,T^(φ))gravity,where R represents the Ricci scalar and T^(φ)exhibits the energy momentum tensor's trace.We examine the stability criteria by performing the dynamical system analysis for our model f(R,T^(φ))=R+2(a T^(φ)+b),where a and b are the constants.We derive a set of autonomous equations and find their solutions by assuming a flat potential V0.We assess the equilibrium points from these equations and find the eigenvalues.We analyze the physical interpretation of the phase space for this system.We obtain three stable equilibrium points.We also examine the interaction between the scalar field and dark energy,represented by Q=ψH_(ρde)and determine the equilibrium points for this interaction.We identify four stable equilibrium points for this interaction.We calculate the values of the physical parameters for both scenarios at each equilibrium point,indicating the Universe's accelerated expansion.
