As the global textile market continues to expand, demand for sewing threads-a critical auxiliary material-is rising. In recent years, automotive interiors, smart outdoor equipment, and medical and ecofriendly products...As the global textile market continues to expand, demand for sewing threads-a critical auxiliary material-is rising. In recent years, automotive interiors, smart outdoor equipment, and medical and ecofriendly products have emerged as new growth engines for the textile industry. This has propelled specialized niche markets for sewing threads designed for these applications, revealing significant and undeniable potential.展开更多
As smart homes become more integrated with daily life,one area of innovation that’s gaining momentum is smart textiles.Historically,fabrics in home design were mostly about aesthetics,adding color,texture,and comfort...As smart homes become more integrated with daily life,one area of innovation that’s gaining momentum is smart textiles.Historically,fabrics in home design were mostly about aesthetics,adding color,texture,and comfort to living spaces.But today,these materials are evolving,incorporating advanced technology to not only elevate visual appeal but also improve home functionality.Smart textiles are offering new ways to optimize energy efficiency,health,safety,and personalization,reshaping how we approach interior design.These fabrics are blurring the lines between decor and technology,making homes smarter and more efficient.展开更多
A major mission of geosciences is to characterize the composition, structure and geodynamic history of the earth＇s continental interiors. Because the evidence for such studies is spread over different disciplines and...A major mission of geosciences is to characterize the composition, structure and geodynamic history of the earth＇s continental interiors. Because the evidence for such studies is spread over different disciplines and in different spatial and temporal scales, advances in understanding the geodynamics of continental interiors often require a multi-disciplinary approach to examine the multiplescale nature of the subjects.展开更多
Global modernity,mobility and movement stand as characteristic features that are shaping current times.Marking and challenging the notion of identity,whether cultural,religious,or political,on a daily basis,is movemen...Global modernity,mobility and movement stand as characteristic features that are shaping current times.Marking and challenging the notion of identity,whether cultural,religious,or political,on a daily basis,is movement from nation to nation,region to region,city to city.Individuals and groups are overcoming and crossing geographical borders and cultural differences for study,tourism,lifestyle,or even to start a new life with their children.Thus,identity can be challenged and redefined,resulting in a hybrid identity.The concept of interiors,especially domestic interiors,while people are moving and stopping has changed and is still changing.This case study was based in the city of Glasgow in the UK,where a qualitative approach was adopted for the study of 20 Arab Muslim participants.Semi-structured interviews were conducted within their current private houses in Glasgow.展开更多
According to a new electron screening theory,we discuss the beta decay rates of nuclide 56Fe,56Co,56Ni,56Mn,56Cr and 56V with and without strong electron screening （SES）.The results show that SES has only a slight e...According to a new electron screening theory,we discuss the beta decay rates of nuclide 56Fe,56Co,56Ni,56Mn,56Cr and 56V with and without strong electron screening （SES）.The results show that SES has only a slight effect on the beta decay rates for ρ/μe 108 g/cm3.However the beta decay rates would be influenced greatly for ρ/μe 108 g/cm3.Due to SES,the maximum values of the C-factor （in %） on beta decay rates of 56Fe,56Co,56Ni,56Mn,56Cr and 56V is of the order of 95.03%,35.02%,98.05%,80.33%,98.30% and 98.71% at T9 = 4.0 and 98.83%,98.89%,99.65%,10.32%,4.10% and 40.21% at T9 = 7.0,respectively.展开更多
From decorative and furniture fabrics to wallpaper,flooring and carpets,to mattresses,bed linen and table linen,Heimtextil brings together a diverse product range for holistic interior design January 13-16,2026.Interi...From decorative and furniture fabrics to wallpaper,flooring and carpets,to mattresses,bed linen and table linen,Heimtextil brings together a diverse product range for holistic interior design January 13-16,2026.Interior designers and buyers from the hospitality and retail sectors find the latest textile and non-textile material innovations under one roof.Leading brands and promising newcomers have already announced their participation.The new hall layout creates targeted synergies for an efficient trade fair visit.展开更多
Feasible and accurate acoustic modeling of external and internal aircraft environments is essential for designing low-noise multi-propeller aircraft.This work proposes a novel sound source equivalent approach using Li...Feasible and accurate acoustic modeling of external and internal aircraft environments is essential for designing low-noise multi-propeller aircraft.This work proposes a novel sound source equivalent approach using Lighthill's sound sources(monopole and dipole point sources)for simulating propeller noise.It establishes data transmission interfaces between aerodynamic acoustics and acoustic-solid coupling.Equations are expanded from acoustic pressure to monopole amplitude and dipole moment vector.The basic assumption is that the propeller noise has similar spatial radiation directivity as the sound point source.The radiation relationships are explicitly built between harmonic propeller noise and dipole sources at cabin cross-sections,and between harmonic propeller noise and monopole sources along cabin longitudinal sections.External acoustic pressure distributions of cabin noise are calculated using Unsteady Reynolds-Averaged Navier-Stokes(URANS)and Ffowcs Williams-Hawkings(FW-H)approach.Interior noise is calculated using frequency domain acoustic-solid coupling.Sound source equivalent approach is used to calculate the equivalent intensity of monopole or dipole point sources for external excitation.To assess accuracy of the proposed approach,both external and interior noise of a turboprop aircraft with four sixbladed propellers are calculated and compared against flight trial results of a C-130J-30 Hercules.The turboprop aircraft adopts the same size parameters as the C-130J-30 Hercules.The present frequency domain acoustic approach is accurate for interior cabin noise.It is beneficial for enhancing the design of the low-noise turboprop aircraft.展开更多
Frankfurt am Main,7 April 2o25.Textile interior design at its best is an inte-gral part of Heimtextil,the most inftuentiailand giobai platform for home and contracttextiles as well as textile design.PatriciaUrquiola e...Frankfurt am Main,7 April 2o25.Textile interior design at its best is an inte-gral part of Heimtextil,the most inftuentiailand giobai platform for home and contracttextiles as well as textile design.PatriciaUrquiola expressed this spectacularly inJaruary in Frankfuirt with her installation'among-us'.展开更多
At low-Reynolds-number,the performance of airfoil is known to be greatly affected by the formation and burst of a laminar separation bubble(LSB),which requires a more precise simulation of the delicate flow structures...At low-Reynolds-number,the performance of airfoil is known to be greatly affected by the formation and burst of a laminar separation bubble(LSB),which requires a more precise simulation of the delicate flow structures.A framework based on the interior penalty discontinuous Galerkin method and large eddy simulation approach was adopted in the present study.The performances of various subgrid models,including the Smagorinsky(SM)model,the dynamic Smagorinsky(DSM)model,the wall-adapting local-eddy-viscosity(WALE)model,and the VREMAN model,have been analyzed through flow simulations of the SD7003 airfoil at a Reynolds number of 60000.It turns out that the SM model fails to predict the emergence of LSB,even modified by the Van-Driest damping function.On the contrary,the best agreement is generally achieved by the WALE model in terms of flow separation,reattachment,and transition locations,together with the aerodynamic loads.Furthermore,the influence of numerical dissipation has also been discussed through the comparison of skin friction and resolved Reynolds stresses.As numerical dissipation decreases,the prediction accuracy of the WALE model degrades.Meanwhile,nonlinear variation could be observed from the performances of the DSM model,which could be attributed to the interaction between the numerical dissipation and the subgrid model.展开更多
The availability of a tremendous amount of seismic data demands seismological researchers to analyze seismic phases efficiently.Recently,deep learning algorithms exhibit a powerful capability of detecting and picking ...The availability of a tremendous amount of seismic data demands seismological researchers to analyze seismic phases efficiently.Recently,deep learning algorithms exhibit a powerful capability of detecting and picking on P-and S-wave phases.However,it remains a challenge to effeciently process enormous teleseismic phases,which are crucial to probe Earth’s interior structures and their dynamics.In this study,we propose a scheme to detect and pick teleseismic phases,such as seismic phase that reflects off the core-mantle boundary(i.e.,PcP)and that reflects off the inner-core boundary(i.e.,PKiKP),from a seismic dataset in Japan.The scheme consists of three steps:1)latent phase traces are truncated from the whole seismogram with theoretical arrival times;2)latent phases are recognized and evaluated by convolutional neural network(CNN)models;3)arrivals of good or fair phase are picked with another CNN models.The testing detection result on 7386 seismograms shows that the scheme recognizes 92.15%and 94.13%of PcP and PKiKP phases.The testing picking result has a mean absolute error of 0.0742 s and 0.0636 s for the PcP and PKiKP phases,respectively.These seismograms were processed in just 5 min for phase detection and picking,demonstrating the efficiency of the proposed scheme in automatic teleseismic phase analysis.展开更多
The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.F...The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.First,the methodology is introduced with the development of an interior ballistics(IB)lumped parameter code(LPC),integrating an original image processing method for calculating the specific regression of propellant grains that compose the gun propellant.The ONERA CFD code CEDRE,equipped with a Dynamic Mesh Technique(DMT),is then used in conjunction with the developed LPC to build a dedicated methodology to calculate IB.First results obtained on the AGARD gun and 40 mm gun test cases are in a good agreement with the existing literature.CEDRE is also used to calculate inter-mediate ballistics(first milliseconds of free flight of the projectile)with a multispecies and reactive approach either starting from the gun muzzle plane or directly following IB.In the latter case,an inverse problem involving a Latin hypercube sampling method is used to find a gun propellant configuration that allows the projectile to reach a given exit velocity and base pressure when IB ends.The methodology developed in this work makes it possible to study the flame front of the intermediate flash and depressurization that occurs in a base bleed(BB)channel at the gun muzzle.Average pressure variations in the BB channel during depressurization are in good agreement with literature.展开更多
The estimation of orientation parameters and correction of lens distortion are crucial problems in the field of Unmanned Aerial Vehicles(UAVs)photogrammetry.In recent years,the utilization of UAVs for aerial photogram...The estimation of orientation parameters and correction of lens distortion are crucial problems in the field of Unmanned Aerial Vehicles(UAVs)photogrammetry.In recent years,the utilization of UAVs for aerial photogrammetry has witnessed a surge in popularity.Typically,UAVs are equipped with low-cost non-metric cameras and a Position and Orientation System(POS).Unfortunately,the Interior Orientation Parameters(IOPs)of the non-metric cameras are not fixed.Whether the lens distortions are large or small,they effect the image coordinates accordingly.Additionally,Inertial Measurement Units(IMUs)often have observation errors.To address these challenges and improve parameter estimation for UAVs Light Detection and Ranging(LiDAR)and photogrammetry,this paper analyzes the accuracy of POS observations obtained from Global Navigation Satellite System Real Time Kinematic(GNSS-RTK)and IMU data.A method that incorporates additional known conditions for parameter estimation,a series of algorithms to simultaneously solve for IOPs,Exterior Orientation Parameters(EOPs),and camera lens distortion correction parameters are proposed.Extensive experiments demonstrate that the coordinates measured by GNSS-RTK can be directly used as linear EOPs;however,angular EOP measurements from IMUs exhibit relatively large errors compared to adjustment results and require correction during the adjustment process.The IOPs of non-metric cameras vary slightly between images but need to be treated as unknown parameters in high precision applications.Furthermore,it is found that the Ebner systematic error model is sensitive to the choice of the magnification parameter of the photographic baseline length in images,it should be set as less than or equal to one third of the photographic baseline to ensure stable solutions.展开更多
We used the ocean reanalysis dataset SODA 2.2.4 to investigate the relationship between the interior branch of subtropical-tropical cells(STCs)in the Pacific Ocean and El Nino-Southern Oscillation(ENSO)over interdecad...We used the ocean reanalysis dataset SODA 2.2.4 to investigate the relationship between the interior branch of subtropical-tropical cells(STCs)in the Pacific Ocean and El Nino-Southern Oscillation(ENSO)over interdecadal timescales between 1930 and 2010,as well as the possible mechanisms involved.Interior transport within the upper pycnocline layers of STCs(InSTC)along 9°S(InSTC9s)shows a significant correlation of 0.54 with ENSO over the study period.However,there is an interdecadal shift in the relationship between InSTC along 9°N(InSTC9n)and ENSO.The correlation coefficient between InSTC9n and ENSO is not statistically significant between 1930 and 1965(PD1),but is as high as 0.68(significant at the 95% confidence level)between 1965 and 2010(PD2).Composite and regression analysis suggests that this shift may be caused by the relationship between InSTC 9 n and the tropical wind field.During PD1,InSTC9n was driven primarily by the local wind field outside equatorial region,with a relatively weak response to the equatorial wind related to ENSO.In contrast,during PD2,the wind field associated with InSTC 9 n showed a similar spatial distribution to that of ENSO within the equatorial region,indicating a close relationship between InSTC9n and ENSO.The wind stress curl associated with ENSO drives the anomalous InSTC9n in off-equatorial regions,whose signal can propagate westward in the form of Rossby wave and modulate the thermal structure of the tropical Pacific,favoring the development of ENSO.The possible connection between the Atlantic Multidecadal Oscillation(AMO)and interdecadal changes in the ENSO-InSTC9n relationship was also examined.There is a significant connection between the AMO and the interdecadal change in the relationship between ENSO and InSTC9n;however,the associated mechanism remains to be explored in future studies.展开更多
Limited-angle tomography of an interior volume is a challenging, highly ill-posed problem with practical implications in medical and biological imaging, manufacturing, automation, and environmental and food security. ...Limited-angle tomography of an interior volume is a challenging, highly ill-posed problem with practical implications in medical and biological imaging, manufacturing, automation, and environmental and food security. Regularizing priors are necessary to reduce artifacts by improving the condition of such problems. Recently, it was shown that one effective way to learn the priors for strongly scattering yet highly structured 3D objects, e.g. layered and Manhattan, is by a static neural network [Goy et al. Proc. Natl. Acad. Sci. 116, 19848–19856 (2019)]. Here, we present a radically different approach where the collection of raw images from multiple angles is viewed analogously to a dynamical system driven by the object-dependent forward scattering operator. The sequence index in the angle of illumination plays the role of discrete time in the dynamical system analogy. Thus, the imaging problem turns into a problem of nonlinear system identification, which also suggests dynamical learning as a better fit to regularize the reconstructions. We devised a Recurrent Neural Network (RNN) architecture with a novel Separable-Convolution Gated Recurrent Unit (SC-GRU) as the fundamental building block. Through a comprehensive comparison of several quantitative metrics, we show that the dynamic method is suitable for a generic interior-volumetric reconstruction under a limited-angle scheme. We show that this approach accurately reconstructs volume interiors under two conditions: weak scattering, when the Radon transform approximation is applicable and the forward operator well defined;and strong scattering, which is nonlinear with respect to the 3D refractive index distribution and includes uncertainty in the forward operator.展开更多
We demonstrate a facile hydrothermal one-pot synthesis method for producing single crystalline mesoporous PtPd bimetallic nanoparticles with a hollow interior and porous surface structure in the presence of Br- and F ...We demonstrate a facile hydrothermal one-pot synthesis method for producing single crystalline mesoporous PtPd bimetallic nanoparticles with a hollow interior and porous surface structure in the presence of Br- and F ions. The formation process analysis indicated that the coexistence of Br- and I- ions is responsible for the formation of the novel bimetallic nanoparticles. The changes in the reduction potential of Pt and Pd metal ions achieved by the coordination with different halide ions resulted in the formation of hollow interiors as a galvanic reaction between Pd2~ and Pt4. ions occurred. In addition, the size of the mesoporous PtPd nanoparticles can be well controlled by slightly changing the amount of I- ions used. The electrochemical tests indicated that the as- synthesized single crystalline mesoporous PtPd hollow nanoparticles exhibited enhanced catalytic properties toward methanol and ethanol oxidation reactions as compared with the commercial Pt black and Pt/C materials.展开更多
INTRODUCTION Our time is now With increasing recognition of the impact of human activity on global climate change,there is now momentum and the will to employ the strategies imperative to reduce greenhouse gas emissio...INTRODUCTION Our time is now With increasing recognition of the impact of human activity on global climate change,there is now momentum and the will to employ the strategies imperative to reduce greenhouse gas emissions and other serious environmental impacts of buildings and interiors.展开更多
If you are fascinated by the trend of minimalism,then a neat and artsy living space is what you'll ultimately strive to be maintain.To succeed,however,a certain amount of daily attention is crucial-ie.picking up c...If you are fascinated by the trend of minimalism,then a neat and artsy living space is what you'll ultimately strive to be maintain.To succeed,however,a certain amount of daily attention is crucial-ie.picking up clothes off the floor-as is making a consistent effort to cultivate your taste.In other words,you'll need to bridge the gap between what you envision for your interior and what your room actually looks like,which is typically much harder than it sounds.展开更多
Low earth orbit(LEO) satellite communications can provide ubiquitous and reliable services,making it an essential part of the Internet of Everything network. Beam hopping(BH) is an emerging technology for effectively ...Low earth orbit(LEO) satellite communications can provide ubiquitous and reliable services,making it an essential part of the Internet of Everything network. Beam hopping(BH) is an emerging technology for effectively addressing the issue of low resource utilization caused by the non-uniform spatio-temporal distribution of traffic demands. However, how to allocate multi-dimensional resources in a timely and efficient way for the highly dynamic LEO satellite systems remains a challenge. This paper proposes a joint beam scheduling and power optimization beam hopping(JBSPO-BH) algorithm considering the differences in the geographic distribution of sink nodes. The JBSPO-BH algorithm decouples the original problem into two sub-problems. The beam scheduling problem is modelled as a potential game,and the Nash equilibrium(NE) point is obtained as the beam scheduling strategy. Moreover, the penalty function interior point method is applied to optimize the power allocation. Simulation results show that the JBSPO-BH algorithm has low time complexity and fast convergence and achieves better performance both in throughput and fairness. Compared with greedybased BH, greedy-based BH with the power optimization, round-robin BH, Max-SINR BH and satellite resource allocation algorithm, the throughput of the proposed algorithm is improved by 44.99%, 20.79%,156.06%, 15.39% and 8.17%, respectively.展开更多
Fault zones have always drawn attention from the industry,and the performance of a quantitative interpretation of the fault interior structure on seismic data has remained as a big challenge.In this work,we focus on q...Fault zones have always drawn attention from the industry,and the performance of a quantitative interpretation of the fault interior structure on seismic data has remained as a big challenge.In this work,we focus on quantitatively populating the heterogeneity of the fault interior structure in a three-dimensional space on seismic data.To realize this goal,we take the South Wuerxun sub-depression in Hailar Basin as an example of a faulted basin.First,based on a heterogeneity analysis using the drilling and logging information from wells,we establish fault zone geologic models and perform seismic forward modeling to determine the relationship between different fault zone models with different fault dips,internal fillings,and P wave responses.Next,the fault interior structure index(FIS)is constructed,and the response features on the FIS from the fault facies and the host rock are observed.Finally,the FIS is applied to perform the quantitative interpretation and prediction of the heterogeneity in the FIS on seismic data.The results show that the FIS response from the fault zone is higher than that of the host rock in plane,indicating that the former is quantitatively separated from the surrounding host rocks.The FIS values greater than 26 represent the feedback from the fault facies,whereas those less than 26 represent the response from the host rocks.The FIS shows segmented features in the strike,banded in dip on plane.On the slip surface,the FIS indicates the shale smear zone and the location where low-graded and small-scaled faults are densely developed.The heterogeneity prediction result is proven by oil and gas exploration activities.The study results imply that the FIS could indicate a favorable path of the hydrocarbon migration in the fault zone and evaluate the fault sealing parts.The method can explore the quantitative characterization of fault facies and has essential popularization and application values in similar geological application fields,including hydrocarbon exploration,development of faulted reservoirs,and geological engineering evaluation related to faults.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
文摘As the global textile market continues to expand, demand for sewing threads-a critical auxiliary material-is rising. In recent years, automotive interiors, smart outdoor equipment, and medical and ecofriendly products have emerged as new growth engines for the textile industry. This has propelled specialized niche markets for sewing threads designed for these applications, revealing significant and undeniable potential.
文摘As smart homes become more integrated with daily life,one area of innovation that’s gaining momentum is smart textiles.Historically,fabrics in home design were mostly about aesthetics,adding color,texture,and comfort to living spaces.But today,these materials are evolving,incorporating advanced technology to not only elevate visual appeal but also improve home functionality.Smart textiles are offering new ways to optimize energy efficiency,health,safety,and personalization,reshaping how we approach interior design.These fabrics are blurring the lines between decor and technology,making homes smarter and more efficient.
文摘A major mission of geosciences is to characterize the composition, structure and geodynamic history of the earth＇s continental interiors. Because the evidence for such studies is spread over different disciplines and in different spatial and temporal scales, advances in understanding the geodynamics of continental interiors often require a multi-disciplinary approach to examine the multiplescale nature of the subjects.
文摘Global modernity,mobility and movement stand as characteristic features that are shaping current times.Marking and challenging the notion of identity,whether cultural,religious,or political,on a daily basis,is movement from nation to nation,region to region,city to city.Individuals and groups are overcoming and crossing geographical borders and cultural differences for study,tourism,lifestyle,or even to start a new life with their children.Thus,identity can be challenged and redefined,resulting in a hybrid identity.The concept of interiors,especially domestic interiors,while people are moving and stopping has changed and is still changing.This case study was based in the city of Glasgow in the UK,where a qualitative approach was adopted for the study of 20 Arab Muslim participants.Semi-structured interviews were conducted within their current private houses in Glasgow.
基金Supported by Natural Science Foundation of Hainan Province (109004)Institution of Higher Education Scientific Research and Foundation of Hainan Provincial Education Department (Hjkj 2010–42)Institution of Higher Education Special Foundation of Sanya (YD09047)
文摘According to a new electron screening theory,we discuss the beta decay rates of nuclide 56Fe,56Co,56Ni,56Mn,56Cr and 56V with and without strong electron screening （SES）.The results show that SES has only a slight effect on the beta decay rates for ρ/μe 108 g/cm3.However the beta decay rates would be influenced greatly for ρ/μe 108 g/cm3.Due to SES,the maximum values of the C-factor （in %） on beta decay rates of 56Fe,56Co,56Ni,56Mn,56Cr and 56V is of the order of 95.03%,35.02%,98.05%,80.33%,98.30% and 98.71% at T9 = 4.0 and 98.83%,98.89%,99.65%,10.32%,4.10% and 40.21% at T9 = 7.0,respectively.
文摘From decorative and furniture fabrics to wallpaper,flooring and carpets,to mattresses,bed linen and table linen,Heimtextil brings together a diverse product range for holistic interior design January 13-16,2026.Interior designers and buyers from the hospitality and retail sectors find the latest textile and non-textile material innovations under one roof.Leading brands and promising newcomers have already announced their participation.The new hall layout creates targeted synergies for an efficient trade fair visit.
基金supported by the National Natural Science Foundation of China(Nos.51576097,51976089)the Funding for Outstanding Doctoral Dissertation in Nanjing University of Aeronautics and Astronautics,China(No.BCXJ24-05)the Aeronautical Science Foundation of China(No.2023L060052001).
文摘Feasible and accurate acoustic modeling of external and internal aircraft environments is essential for designing low-noise multi-propeller aircraft.This work proposes a novel sound source equivalent approach using Lighthill's sound sources(monopole and dipole point sources)for simulating propeller noise.It establishes data transmission interfaces between aerodynamic acoustics and acoustic-solid coupling.Equations are expanded from acoustic pressure to monopole amplitude and dipole moment vector.The basic assumption is that the propeller noise has similar spatial radiation directivity as the sound point source.The radiation relationships are explicitly built between harmonic propeller noise and dipole sources at cabin cross-sections,and between harmonic propeller noise and monopole sources along cabin longitudinal sections.External acoustic pressure distributions of cabin noise are calculated using Unsteady Reynolds-Averaged Navier-Stokes(URANS)and Ffowcs Williams-Hawkings(FW-H)approach.Interior noise is calculated using frequency domain acoustic-solid coupling.Sound source equivalent approach is used to calculate the equivalent intensity of monopole or dipole point sources for external excitation.To assess accuracy of the proposed approach,both external and interior noise of a turboprop aircraft with four sixbladed propellers are calculated and compared against flight trial results of a C-130J-30 Hercules.The turboprop aircraft adopts the same size parameters as the C-130J-30 Hercules.The present frequency domain acoustic approach is accurate for interior cabin noise.It is beneficial for enhancing the design of the low-noise turboprop aircraft.
文摘Frankfurt am Main,7 April 2o25.Textile interior design at its best is an inte-gral part of Heimtextil,the most inftuentiailand giobai platform for home and contracttextiles as well as textile design.PatriciaUrquiola expressed this spectacularly inJaruary in Frankfuirt with her installation'among-us'.
基金This work was supported by the National Key R&D Program of China(Grant No.2022YFE0207000)the National Natural Science Foundation of China(Grant Nos.12372289,11972250,and 12102298)+1 种基金the China Postdoctoral Science Foundation(Grant No.2021M702443)Tianjin Natural Science Foundation(Grant No.22JCZDJC00910).
文摘At low-Reynolds-number,the performance of airfoil is known to be greatly affected by the formation and burst of a laminar separation bubble(LSB),which requires a more precise simulation of the delicate flow structures.A framework based on the interior penalty discontinuous Galerkin method and large eddy simulation approach was adopted in the present study.The performances of various subgrid models,including the Smagorinsky(SM)model,the dynamic Smagorinsky(DSM)model,the wall-adapting local-eddy-viscosity(WALE)model,and the VREMAN model,have been analyzed through flow simulations of the SD7003 airfoil at a Reynolds number of 60000.It turns out that the SM model fails to predict the emergence of LSB,even modified by the Van-Driest damping function.On the contrary,the best agreement is generally achieved by the WALE model in terms of flow separation,reattachment,and transition locations,together with the aerodynamic loads.Furthermore,the influence of numerical dissipation has also been discussed through the comparison of skin friction and resolved Reynolds stresses.As numerical dissipation decreases,the prediction accuracy of the WALE model degrades.Meanwhile,nonlinear variation could be observed from the performances of the DSM model,which could be attributed to the interaction between the numerical dissipation and the subgrid model.
文摘The availability of a tremendous amount of seismic data demands seismological researchers to analyze seismic phases efficiently.Recently,deep learning algorithms exhibit a powerful capability of detecting and picking on P-and S-wave phases.However,it remains a challenge to effeciently process enormous teleseismic phases,which are crucial to probe Earth’s interior structures and their dynamics.In this study,we propose a scheme to detect and pick teleseismic phases,such as seismic phase that reflects off the core-mantle boundary(i.e.,PcP)and that reflects off the inner-core boundary(i.e.,PKiKP),from a seismic dataset in Japan.The scheme consists of three steps:1)latent phase traces are truncated from the whole seismogram with theoretical arrival times;2)latent phases are recognized and evaluated by convolutional neural network(CNN)models;3)arrivals of good or fair phase are picked with another CNN models.The testing detection result on 7386 seismograms shows that the scheme recognizes 92.15%and 94.13%of PcP and PKiKP phases.The testing picking result has a mean absolute error of 0.0742 s and 0.0636 s for the PcP and PKiKP phases,respectively.These seismograms were processed in just 5 min for phase detection and picking,demonstrating the efficiency of the proposed scheme in automatic teleseismic phase analysis.
基金the French Defense Innovation Agency (AID)the French Procurement Agency for Armament (DGA)ONERA's scientific direction for funding and supporting the present work
文摘The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.First,the methodology is introduced with the development of an interior ballistics(IB)lumped parameter code(LPC),integrating an original image processing method for calculating the specific regression of propellant grains that compose the gun propellant.The ONERA CFD code CEDRE,equipped with a Dynamic Mesh Technique(DMT),is then used in conjunction with the developed LPC to build a dedicated methodology to calculate IB.First results obtained on the AGARD gun and 40 mm gun test cases are in a good agreement with the existing literature.CEDRE is also used to calculate inter-mediate ballistics(first milliseconds of free flight of the projectile)with a multispecies and reactive approach either starting from the gun muzzle plane or directly following IB.In the latter case,an inverse problem involving a Latin hypercube sampling method is used to find a gun propellant configuration that allows the projectile to reach a given exit velocity and base pressure when IB ends.The methodology developed in this work makes it possible to study the flame front of the intermediate flash and depressurization that occurs in a base bleed(BB)channel at the gun muzzle.Average pressure variations in the BB channel during depressurization are in good agreement with literature.
基金Natural Science Foundation of Hunan Province,China(No.2024JJ8335)Open Topic of Hunan Geospatial Information Engineering and Technology Research Center,China(No.HNGIET2023004).
文摘The estimation of orientation parameters and correction of lens distortion are crucial problems in the field of Unmanned Aerial Vehicles(UAVs)photogrammetry.In recent years,the utilization of UAVs for aerial photogrammetry has witnessed a surge in popularity.Typically,UAVs are equipped with low-cost non-metric cameras and a Position and Orientation System(POS).Unfortunately,the Interior Orientation Parameters(IOPs)of the non-metric cameras are not fixed.Whether the lens distortions are large or small,they effect the image coordinates accordingly.Additionally,Inertial Measurement Units(IMUs)often have observation errors.To address these challenges and improve parameter estimation for UAVs Light Detection and Ranging(LiDAR)and photogrammetry,this paper analyzes the accuracy of POS observations obtained from Global Navigation Satellite System Real Time Kinematic(GNSS-RTK)and IMU data.A method that incorporates additional known conditions for parameter estimation,a series of algorithms to simultaneously solve for IOPs,Exterior Orientation Parameters(EOPs),and camera lens distortion correction parameters are proposed.Extensive experiments demonstrate that the coordinates measured by GNSS-RTK can be directly used as linear EOPs;however,angular EOP measurements from IMUs exhibit relatively large errors compared to adjustment results and require correction during the adjustment process.The IOPs of non-metric cameras vary slightly between images but need to be treated as unknown parameters in high precision applications.Furthermore,it is found that the Ebner systematic error model is sensitive to the choice of the magnification parameter of the photographic baseline length in images,it should be set as less than or equal to one third of the photographic baseline to ensure stable solutions.
基金Supported by the National Natural Science Foundation of China(No.41976027)the Laoshan Laboratory(No.LSKJ202201601)。
文摘We used the ocean reanalysis dataset SODA 2.2.4 to investigate the relationship between the interior branch of subtropical-tropical cells(STCs)in the Pacific Ocean and El Nino-Southern Oscillation(ENSO)over interdecadal timescales between 1930 and 2010,as well as the possible mechanisms involved.Interior transport within the upper pycnocline layers of STCs(InSTC)along 9°S(InSTC9s)shows a significant correlation of 0.54 with ENSO over the study period.However,there is an interdecadal shift in the relationship between InSTC along 9°N(InSTC9n)and ENSO.The correlation coefficient between InSTC9n and ENSO is not statistically significant between 1930 and 1965(PD1),but is as high as 0.68(significant at the 95% confidence level)between 1965 and 2010(PD2).Composite and regression analysis suggests that this shift may be caused by the relationship between InSTC 9 n and the tropical wind field.During PD1,InSTC9n was driven primarily by the local wind field outside equatorial region,with a relatively weak response to the equatorial wind related to ENSO.In contrast,during PD2,the wind field associated with InSTC 9 n showed a similar spatial distribution to that of ENSO within the equatorial region,indicating a close relationship between InSTC9n and ENSO.The wind stress curl associated with ENSO drives the anomalous InSTC9n in off-equatorial regions,whose signal can propagate westward in the form of Rossby wave and modulate the thermal structure of the tropical Pacific,favoring the development of ENSO.The possible connection between the Atlantic Multidecadal Oscillation(AMO)and interdecadal changes in the ENSO-InSTC9n relationship was also examined.There is a significant connection between the AMO and the interdecadal change in the relationship between ENSO and InSTC9n;however,the associated mechanism remains to be explored in future studies.
基金The authors acknowledge funding from Intelligence Advanced Research Projects Activity(FA8650-17-C-9113).
文摘Limited-angle tomography of an interior volume is a challenging, highly ill-posed problem with practical implications in medical and biological imaging, manufacturing, automation, and environmental and food security. Regularizing priors are necessary to reduce artifacts by improving the condition of such problems. Recently, it was shown that one effective way to learn the priors for strongly scattering yet highly structured 3D objects, e.g. layered and Manhattan, is by a static neural network [Goy et al. Proc. Natl. Acad. Sci. 116, 19848–19856 (2019)]. Here, we present a radically different approach where the collection of raw images from multiple angles is viewed analogously to a dynamical system driven by the object-dependent forward scattering operator. The sequence index in the angle of illumination plays the role of discrete time in the dynamical system analogy. Thus, the imaging problem turns into a problem of nonlinear system identification, which also suggests dynamical learning as a better fit to regularize the reconstructions. We devised a Recurrent Neural Network (RNN) architecture with a novel Separable-Convolution Gated Recurrent Unit (SC-GRU) as the fundamental building block. Through a comprehensive comparison of several quantitative metrics, we show that the dynamic method is suitable for a generic interior-volumetric reconstruction under a limited-angle scheme. We show that this approach accurately reconstructs volume interiors under two conditions: weak scattering, when the Radon transform approximation is applicable and the forward operator well defined;and strong scattering, which is nonlinear with respect to the 3D refractive index distribution and includes uncertainty in the forward operator.
基金We thank Dr. Chuansheng Ma from the International Center for Dielectric Research, Xi＇an Jiaotong University, for their support with HRTEM, Xiaojing Zhang and Liqun Wang from the School of Science, Xi＇an Jiaotong University, for their support of TEM and SEM characterizations. This work is supported by National Natural Science Foundation of China （No. 51271135）, the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, the Fundamental Research Funds for the Central Universities, and the Natural Science Foundation of Shanxi Province （No. 2015JM5166）.
文摘We demonstrate a facile hydrothermal one-pot synthesis method for producing single crystalline mesoporous PtPd bimetallic nanoparticles with a hollow interior and porous surface structure in the presence of Br- and F ions. The formation process analysis indicated that the coexistence of Br- and I- ions is responsible for the formation of the novel bimetallic nanoparticles. The changes in the reduction potential of Pt and Pd metal ions achieved by the coordination with different halide ions resulted in the formation of hollow interiors as a galvanic reaction between Pd2~ and Pt4. ions occurred. In addition, the size of the mesoporous PtPd nanoparticles can be well controlled by slightly changing the amount of I- ions used. The electrochemical tests indicated that the as- synthesized single crystalline mesoporous PtPd hollow nanoparticles exhibited enhanced catalytic properties toward methanol and ethanol oxidation reactions as compared with the commercial Pt black and Pt/C materials.
文摘INTRODUCTION Our time is now With increasing recognition of the impact of human activity on global climate change,there is now momentum and the will to employ the strategies imperative to reduce greenhouse gas emissions and other serious environmental impacts of buildings and interiors.
文摘If you are fascinated by the trend of minimalism,then a neat and artsy living space is what you'll ultimately strive to be maintain.To succeed,however,a certain amount of daily attention is crucial-ie.picking up clothes off the floor-as is making a consistent effort to cultivate your taste.In other words,you'll need to bridge the gap between what you envision for your interior and what your room actually looks like,which is typically much harder than it sounds.
基金supported by the National Key Research and Development Program of China 2021YFB2900504, 2020YFB1807900。
文摘Low earth orbit(LEO) satellite communications can provide ubiquitous and reliable services,making it an essential part of the Internet of Everything network. Beam hopping(BH) is an emerging technology for effectively addressing the issue of low resource utilization caused by the non-uniform spatio-temporal distribution of traffic demands. However, how to allocate multi-dimensional resources in a timely and efficient way for the highly dynamic LEO satellite systems remains a challenge. This paper proposes a joint beam scheduling and power optimization beam hopping(JBSPO-BH) algorithm considering the differences in the geographic distribution of sink nodes. The JBSPO-BH algorithm decouples the original problem into two sub-problems. The beam scheduling problem is modelled as a potential game,and the Nash equilibrium(NE) point is obtained as the beam scheduling strategy. Moreover, the penalty function interior point method is applied to optimize the power allocation. Simulation results show that the JBSPO-BH algorithm has low time complexity and fast convergence and achieves better performance both in throughput and fairness. Compared with greedybased BH, greedy-based BH with the power optimization, round-robin BH, Max-SINR BH and satellite resource allocation algorithm, the throughput of the proposed algorithm is improved by 44.99%, 20.79%,156.06%, 15.39% and 8.17%, respectively.
基金sponsored by the Subordinate subject of the National Major Science and Technology Project“Development of Large Oil and Gas Fields and coalbed methane”(2017ZX05001-003)supported by the Science Research Project from CNPC(2019D-0708)supported by the National Natural Science Foundation of China"Quantitative evaluation of sealing capacity of fault rocks with diff erent structures in clastic strata”(41872153).
文摘Fault zones have always drawn attention from the industry,and the performance of a quantitative interpretation of the fault interior structure on seismic data has remained as a big challenge.In this work,we focus on quantitatively populating the heterogeneity of the fault interior structure in a three-dimensional space on seismic data.To realize this goal,we take the South Wuerxun sub-depression in Hailar Basin as an example of a faulted basin.First,based on a heterogeneity analysis using the drilling and logging information from wells,we establish fault zone geologic models and perform seismic forward modeling to determine the relationship between different fault zone models with different fault dips,internal fillings,and P wave responses.Next,the fault interior structure index(FIS)is constructed,and the response features on the FIS from the fault facies and the host rock are observed.Finally,the FIS is applied to perform the quantitative interpretation and prediction of the heterogeneity in the FIS on seismic data.The results show that the FIS response from the fault zone is higher than that of the host rock in plane,indicating that the former is quantitatively separated from the surrounding host rocks.The FIS values greater than 26 represent the feedback from the fault facies,whereas those less than 26 represent the response from the host rocks.The FIS shows segmented features in the strike,banded in dip on plane.On the slip surface,the FIS indicates the shale smear zone and the location where low-graded and small-scaled faults are densely developed.The heterogeneity prediction result is proven by oil and gas exploration activities.The study results imply that the FIS could indicate a favorable path of the hydrocarbon migration in the fault zone and evaluate the fault sealing parts.The method can explore the quantitative characterization of fault facies and has essential popularization and application values in similar geological application fields,including hydrocarbon exploration,development of faulted reservoirs,and geological engineering evaluation related to faults.
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.
