1 Authorities in Montgomery Township,Pennsylvania,have introduced wavy lane patterns on some streets in an effort to slow down traffic in the area.2 Driving along Grays Lane in Montgomery Township for the first time m...1 Authorities in Montgomery Township,Pennsylvania,have introduced wavy lane patterns on some streets in an effort to slow down traffic in the area.2 Driving along Grays Lane in Montgomery Township for the first time must be challenging.Thats because the regular lane patterns have been replaced by wavy and zig⁃zag lines that look like they were painted by a drunk.But they are wavy by design.According to Montgomery Township officials,the unusual patterns were thought as the best solution to discouraging speeding on some of the streets.Police sources told local media outlets that the“traffic⁃calming measures”were installed in response to numerous complaints about certain streets being used as“speedways”.展开更多
In recent decades,capacitive pressure sensors(CPSs)with high sensitivity have demonstrated significant potential in applications such as medical monitoring,artificial intelligence,and soft robotics.Efforts to enhance ...In recent decades,capacitive pressure sensors(CPSs)with high sensitivity have demonstrated significant potential in applications such as medical monitoring,artificial intelligence,and soft robotics.Efforts to enhance this sensitivity have predominantly focused on material design and structural optimization,with surface microstructures such as wrinkles,pyramids,and micro-pillars proving effective.Although finite element modeling(FEM)has guided enhancements in CPS sensitivity across various surface designs,a theoretical understanding of sensitivity improvements remains underexplored.This paper employs sinusoidal wavy surfaces as a representative model to analytically elucidate the underlying mechanisms of sensitivity enhancement through contact mechanics.These theoretical insights are corroborated by FEM and experimental validations.Our findings underscore that optimizing material properties,such as Young’s modulus and relative permittivity,alongside adjustments in surface roughness and substrate thickness,can significantly elevate the sensitivity.The optimal performance is achieved when the amplitude-to-wavelength ratio(H/)is about 0.2.These results offer critical insights for designing ultrasensitive CPS devices,paving the way for advancements in sensor technology.展开更多
Rod-airfoil interaction noise becomes a major issue in some aeronautical applications.The design of four wavy leading edges(WLEs)with varying wavelengths,bioinspired by the tubercles on humpback whales’flippers,aims ...Rod-airfoil interaction noise becomes a major issue in some aeronautical applications.The design of four wavy leading edges(WLEs)with varying wavelengths,bioinspired by the tubercles on humpback whales’flippers,aims to mitigate far-field noise.Among these cases,a reduction in the wavelength is found to be advantageous for noise suppression,with the smallest wavelength case achieving a maximum noise reduction of 1.9 dB.Furthermore,the noise radiation induced by WLEs is suppressed mainly at medium frequencies.The theory of multiprocess aeroacoustics is applied to reveal their underlying mechanisms.The dominant factor is the source cutoff effect,which significantly decreases the source strength on hills.Additionally,spanwise decoherence with phase interference serves as another crucial mechanism,particularly for reducing mid-frequency noise.展开更多
This study evaluates the physical mechanisms of incident waves as they interact with a porous wavy barrier of finite thickness.A wave-trapping chamber is formed between the thick wavy barrier(TWB)and partially reflect...This study evaluates the physical mechanisms of incident waves as they interact with a porous wavy barrier of finite thickness.A wave-trapping chamber is formed between the thick wavy barrier(TWB)and partially reflecting seawall(PRS).The effect of seabed undulations is incorporated into the wave-trapping analysis of the TWB.The boundary value problem proposed in this study is solved using a multidomain boundary element method within the context of linear potential flow theory.Coefficients such as reflection,runup,horizontal force on PRS,and vertical force on TWB are examined for various structural configurations.The position of seabed undulations is analyzed for four scenarios:i)seabed undulations upwave of the wavy barrier with a trapping chamber,ii)seabed undulations upwave of the wavy barrier without a trapping chamber,iii)seabed undulations underneath the wavy barrier with a trapping chamber,and iv)seabed undulations beneath the wavy barrier without a trapping chamber.The study results are compared with known results to verify their accuracy.The effects of PRS,TWB porosity,trapping chamber,plate thickness,seabed type,and submergence depth on hydrodynamic coefficients are analyzed against relative water depth.The study reveals that the introduction of a porous TWB with a trapping chamber results in minimal hydrodynamic coefficients(reduced reflection and force on a wall)compared to a rigid TWB without a trapping chamber.A comparison of various seabeds is reported for all combinations of TWB with a chamber.The sloping seabed upwave of the barrier with a trapping chamber,20%plate porosity,and 50%wall reflection at an appropriate submergence depth could replace gravity-type breakwaters in deeper waters.This study holds great potential for analyzing wave trapping coefficients by TWB to provide an effective coastal protection system.展开更多
High-density planting increases maize yield but also canopy crowding and stalk lodging.Aiming this contradiction,a wavy canopy was created using interlaced chemical application(IC)of a plant growth retardant at the V1...High-density planting increases maize yield but also canopy crowding and stalk lodging.Aiming this contradiction,a wavy canopy was created using interlaced chemical application(IC)of a plant growth retardant at the V14 stage with three densities(60,000,75,000,and 90,000 plants ha-1,indicated by D1,D2,and D3,respectively)for two seasons.The results showed that the IC-treated wavy canopy featuring both natural height(IC-H)and dwarfed(IC-L)plants,improved light transmission by 8.54%,8.49%,and 16.49%on average than the corresponding controls(CK)at D1,D2,and D3,respectively.The alleviation of canopy crowding stimulated leaf photosynthesis,sugar availability,basal-internode strength,and decreased plant lodging ratios in both IC-H and IC-L,particularly under higher densities.Meanwhile,the IC populations produced significantly higher yield than CK,with an average increase of 3.38%,16.70%,and 15.28%at D1,D2,and D3,respectively.Collectively,this study proposed a new wavy canopy strategy using plant growth retardant to simultaneously increase yield performance and lodging resistance,thus offering a sustainable solution for further development of high-density maize production.展开更多
Shale reservoirs have abundant bedding structures,which deeply alter the mechanical properties of rocks,and thus affect the reservoir stimulation performance.Previous research mostly focuses on the effects of parallel...Shale reservoirs have abundant bedding structures,which deeply alter the mechanical properties of rocks,and thus affect the reservoir stimulation performance.Previous research mostly focuses on the effects of parallel bedding on fracture propagation,while the mechanical properties and mechanisms of fracture propagation remain unclear for rocks with complex wavy bedding(e.g.China’s continentalorigin Gulong shale).Herein,a mixed phase-field fracture model of the wavy-bedding shale was applied,based on the local tension-compression decomposition phase field method(PFM)and geometric structure generation algorithm for the bedding with controllable morphological features.The parametric analysis of fracture propagation behaviors in the case of abundant complex bedding structures showed that with wavy bedding,the vertical fracture propagation rate is far higher than the horizontal propagation rate.Moreover,the development of branch fractures is suppressed during the fracturing process of the wavy-bedding sample,and the stimulated volume is limited,which is different from the characteristic of parallel bedding that promotes horizontal fracture initiation and propagation.The results showed that larger amplitudes,higher frequencies,higher inclination angles,and larger strengths of wavy bedding all promote the formation of vertical penetrating fractures and suppress the growth of branch fractures.Under such circumstances,it is hard to create a well-connected fracture network after fracturing.This research may provide a theoretical basis for understanding fracture behaviors in rocks with such complex wavy bedding.展开更多
The noise generated by subsonic jet nozzles, commonly encountered in civilian aircraft, is rather significant and propagates in both the upstream and downstream directions due to large-scale and fine-scale turbulence ...The noise generated by subsonic jet nozzles, commonly encountered in civilian aircraft, is rather significant and propagates in both the upstream and downstream directions due to large-scale and fine-scale turbulence structures. In this paper, a distinctive inner wall treatment strategy, denoted as the Azimuthally-distributed Wavy Inner Wall (AWIW), is proposed, which is aimed at mitigating jet noise. Within this strategy, a circumferentially dispersed treatment wall characterized by a minute wavy pattern is substituted for the smooth inner wall in proximity to the nozzle outlet. To assess the effectiveness of the AWIW treatment, we conducted numerical simulations. The unsteady flow field and far-field noise were predicted by employing Large Eddy Simulations (LES) coupled with the Ffowcs Williams and Hawkings (FW-H) integration method. To gain a comprehensive understanding of the mechanism underlying the noise reduction facilitated by the AWIW treatment, it examined physical parameters such as the Lighthill source acoustic source term, the turbulent kinetic energy acoustic source term, and the shear layer instability. The results reveal that the AWIW treatment expedites the instability within the shear layer of the jet, leading to an early disruption of the jet shear layer, and consequently turbulent structures in varying sizes are generated downstream. This process effectively regulates the generation and emission of jet noise. By controlling the minor scale turbulence through the AWIW treatment, the mid- and high-frequency noise within the distant field can be significantly reduced. In the context of the flow field, the introduction of AWIW also leads to a decrease in drag on the inner wall surface of the jet, thereby improving the overall aerodynamic performance of the nozzle. Considering these attributes, the AWIW strategy emerges as a viable technique for the reduction of jet noise.展开更多
This study involved numerical simulations of a double tube heat exchanger using the ANSYS FLUENT programversion 22.The study aims to examine methods for minimizing pressure loss and consequently enhancing the thermal ...This study involved numerical simulations of a double tube heat exchanger using the ANSYS FLUENT programversion 22.The study aims to examine methods for minimizing pressure loss and consequently enhancing the thermal performance index(TPI)of a heat exchanger fitted with wavy edge tape that is a heat recovery system(the hot air in simulation instead of t heat from the exhaust gases of the brick factory furnaces and return it to warm the heavy fuel oil by substituting the electrical heater with a heat exchanger to recuperate waste heat from the flue gases,so elevating the temperature of Heavy fuel oil(HFO)to inject from the roof nozzles of combustion chamber of the furnace furthermore reducing cost(by finding the optimal design of wavy edge tape))and energy consumption.Air was selected as the hot gas in the inner pipe instead of furnace exhaust gases due to their similar thermal characteristics.A numerical analysis was conducted to create a novel wavy edge tape with varying widths(50%Di,75%Di,and 95%Di),lengths(1000,1200,1400)mm,amplitudes(5,10,15)mm,and periods of wavy length(5,10,15)mm.The flow rate of the outer pipe fluid(oil)ranges from(0.06 to 0.1)kg/s,while the velocity of the hot fluid(air)varies from(1 to 27)m/s,Re_(air)(6957 to 187,837).The entrance temperature of the hot fluid can be either(200,225,and 250)℃.The study finds that wavy edge tape tubes are more effective than smooth tubes in terms of oil outlet temperature;results revealed that an increase in the oil mass flow rate leads to a decrease in the oil outlet temperature and an increase in the heat transfer rate,at the air temperature 250℃.Additionally,the results indicate that increasing the width,length,and amplitude also leads to an increase in the oil outlet temperature of(94-94.12)℃,the pressure drop of(568.3)Pa,and the Nusselt number(65.7-66.5)respectively on the oil side.Finally,the heat exchanger’s best thermal performance index was found by investigating temperature contour at amplitude(A=5),period(p=15),width(w=75%Di),and length(L=1200 mm).The values for these parameters are,in order(1.02,1.025,1.02,and 1.0077).展开更多
As a popular approach to producing atmospheric pressure non-thermal plasma,dielectric barrier discharge(DBD)has been extensively used in various application fields.In this paper,DBD with wavy dielectric layers is nume...As a popular approach to producing atmospheric pressure non-thermal plasma,dielectric barrier discharge(DBD)has been extensively used in various application fields.In this paper,DBD with wavy dielectric layers is numerically simulated in atmospheric pressure helium mixed with trace nitrogen based on a fluid model.With varying relative position(phase difference(Δφ))of the wavy surfaces,there is a positive discharge and a negative discharge per voltage cycle,each of which consists of a pulse stage and a hump stage.For the pulse stage,maximal current increases with increasingΔφ.Results show that DBD with the wavy surfaces appears as discrete micro-discharges(MDs),which are self-organized to different patterns with varyingΔφ.The MDs are vertical and uniformly-spaced withΔφ=0,which are self-organized in pairs withΔφ=π/4.These MD pairs are merged into some bright wide MDs withΔφ=π/2.In addition,narrow MDs appear between tilted wide MDs withΔφ=3π/4.WithΔφ=π,the pattern is composed of wide and narrow MDs,which are vertical and appear alternately.To elucidate the formation mechanism of the patterns with differentΔφ,temporal evolutions of electron density and electric field are investigated for the positive discharge.Moreover,surface charge on the wavy dielectric layers has also been compared with differentΔφ.展开更多
The goal of this paper is to represent a numerical study of magnetohydrodynamic mixed convection heat transfer in a lid-driven vertical wavy enclosure with a fin attached to the bottomwall.We use a finite elementmetho...The goal of this paper is to represent a numerical study of magnetohydrodynamic mixed convection heat transfer in a lid-driven vertical wavy enclosure with a fin attached to the bottomwall.We use a finite elementmethod based on Galerkin weighted residual(GWR)techniques to set up the appropriate governing equations for the present flow model.We have conducted a parametric investigation to examine the impact of Hartmann and Richardson numbers on the flow pattern and heat transmission features inside a wavy cavity.We graphically represent the numerical results,such as isotherms,streamlines,velocity profiles,local and mean Nusselt numbers,and average surface temperature.Comparisons between the results of this work and previously published work in a literature review have been produced to examine the reliability and consistency of the data.The different sizes of the fin surface significantly impact flow creation and temperature fields.Additionally,the long fin size is necessary to enhance the heat transfer rate on the right surface at large Richardson numbers and low Hartmann numbers.Fin surfaces can significantly increase the mixing of fluid inside the enclosure,which can mean reductions in reaction times and operating costs,along with increases in heat transfer and efficiency.展开更多
In this paper,the unsteady magnetohydrodynamic(MHD)-radiation-natural convection of a hybrid nanofluid within a U-shaped wavy porous cavity is investigated.This problem has relevant applications in optimizing thermal ...In this paper,the unsteady magnetohydrodynamic(MHD)-radiation-natural convection of a hybrid nanofluid within a U-shaped wavy porous cavity is investigated.This problem has relevant applications in optimizing thermal management systems in electronic devices,solar energy collectors,and other industrial applications where efficient heat transfer is very important.The study is based on the application of a numerical approach using the Finite Difference Method(FDM)for the resolution of the governing equations,which incorporates the Rosseland approximation for thermal radiation and the Darcy-Brinkman-Forchheimer model for porous media.It was found that the increase of Hartmann number(Ha)causes a reduction of the average Nusselt number(Nu),with a maximum decrease of 25%observed as Ha increases from 0 to 50.In addition,the influence of the wall’s wave amplitude and the heat source length on the heat transfer rate was quantified,and it was revealed that at high wave amplitude,the average Nu increases by up to 15%.These findings suggest that manipulating magnetic field strength and cavity geometry can significantly enhance thermal performance.The novelty of this is related to the exploration of a U-shaped wavy cavity,which is not covered in previous studies,and to the detailed examination of the combined effects of magnetic fields,radiation,and hybrid nanofluids.展开更多
Large Eddy Simulation（LES） is performed to investigate the airfoil broadband noise reduction with wavy leading edge under anisotropic incoming turbulence. The anisotropic incoming turbulence is generated by a rod wi...Large Eddy Simulation（LES） is performed to investigate the airfoil broadband noise reduction with wavy leading edge under anisotropic incoming turbulence. The anisotropic incoming turbulence is generated by a rod with a diameter of 10 mm. The incoming flow velocity is 40 m/s and the corresponding Reynolds numbers based on airfoil chord and rod diameter are about 397000 and 26000, respectively. The far-field acoustic field is predicted using an acoustic analogy method which has been validated by the experiment. A straight leading edge airfoil and a wavy leading edge airfoil are simulated. The results show that wavy leading edge increases the airfoil lift and drag whereas the lift and drag fluctuations are substantially reduced. In addition, wavy leading edge can significantly change the flow pattern around the leading edge and a pair of counter-rotating streamwise vortices stemming from each wavy leading edge peak are observed.An averaged noise reduction of 9.5 dB is observed with the wavy leading edge at the azimuthal angle of 90°. Moreover, the wavy leading edge can mitigate noise radiation at all the azimuthal angles without significantly changing the noise directivity. The underlying noise reduction mechanisms are then analyzed in detail.展开更多
The Xu ＆ Yan scale-adaptive simulation （XYSAS） model is employed to simulate the flows past wavy cylinders at Reynolds number 8 × 10 3.This approach yields results in good agreement with experimental measureme...The Xu ＆ Yan scale-adaptive simulation （XYSAS） model is employed to simulate the flows past wavy cylinders at Reynolds number 8 × 10 3.This approach yields results in good agreement with experimental measurements.The mean flow field and near wake vortex structure are replicated and compared with that of a corresponding circular cylinder.The effects of wavelength ratios λ/D m from 3 to 7,together with the amplitude ratios a /D m of 0.091 and 0.25,are fully investigated.Owing to the wavy configuration,a maximum reduction of Strouhal number and root-meansquare （r.m.s） fluctuating lift coefficients are up to 50% and 92%,respectively,which means the vortex induced vibration （VIV） could be effectively alleviated at certain larger values of λ/D m and a /D m.Also,the drag coefficients can be reduced by 30%.It is found that the flow field presents contrary patterns with the increase of λ/D m.The free shear layer becomes much more stable and rolls up into mature vortex only further downstream when λ/D m falls in the range of 5-7.The amplitude ratio a /D m greatly changes the separation line,and subsequently influences the wake structures.展开更多
In this paper,a numerical simulation of flow-induced noise by the low Mach number turbulent flow with a sinusoidal wavy wall was presented based on the unsteady incompressible Navier-Stokes equations and Lighthill'...In this paper,a numerical simulation of flow-induced noise by the low Mach number turbulent flow with a sinusoidal wavy wall was presented based on the unsteady incompressible Navier-Stokes equations and Lighthill's acoustic analogy.Large eddy simulation (LES) was used to investigate the space-time flow field and the Smagorinsky sub-grid scale (SGS) model was introduced for turbulence model.Using Lighthill's acoustics analogy,the flow field simulated by LES was taken as near-field sound sources and radiated sound from turbulent flow was computed by the Curle's integral formulation under the low Mach number approximation.Both spanwise wavy wall and streamwise wavy wall with various wall wave amplitudes were discussed to investigate their effects on reducing the drag and flow noise.The relationship between flow noise and drag on the wavy wall is also studied.展开更多
As reported in a previous work by Lin et al.(Acta Meeh Sin, 2018. https://doi.org/10.1007/s 10409-018-0758-z), an interesting phenomenon was discovered based on the analysis of wavy vortex and vorticity distribution i...As reported in a previous work by Lin et al.(Acta Meeh Sin, 2018. https://doi.org/10.1007/s 10409-018-0758-z), an interesting phenomenon was discovered based on the analysis of wavy vortex and vorticity distribution in the shear layers and near wake of a peak-perforated conic shroud, and two sign laws were summarized. In the present paper, the theory of a vortex-induced vortex is introduced to explore mechanisms in a wavy vortex and applicable sign laws for uniform and incompressible flow past a fixed bluff body. Based on the analysis of the nearest-wall How, two vortex-induced models for streamwise and vertical vortex pairs, respectively, are proposed under two boundary cases, denoting the induced vorticity introduced or distributed on and near the walls. As a result, the first sign law, for only streamwise and vertical components of vorticity, and the second sign law, for three components of vorticity, are obtained under their own particular conditions. The first sign law reveals the intrinsic physical relationship between streamwise and vertical vorticities, independent of the distribution of spanwise vortices in the whole flow field. It is also confirmed that the spanwise vortices, as well as the shear layers and wake width, distributed wavily across the span, are attributed to the introduced streamwise or vertical vortices. The two sign laws for vorticity are independent of the disturbed spanwise wavelength and the Reynolds number. Through the analysis of flow past the conic shroud, the two sign laws are successfully used to summarize typical spacial distributions of vorticity in three flow regions: on and near the front cylinder surfaces, the separated shear layers and the near wake.展开更多
Magnetohydrodynamic （MHD） bioconvection of an incompressible electrically conducting nanofluid near a vertical wavy surface saturated porous medium containing both nanoparticle and gyrotactic microorganisms is inves...Magnetohydrodynamic （MHD） bioconvection of an incompressible electrically conducting nanofluid near a vertical wavy surface saturated porous medium containing both nanoparticle and gyrotactic microorganisms is investigated. The nanofluid is represented by a model that includes both Brownian motion and thermophoresis effects. A suitable set of non-dimensional variables are used to transform the governing boundary layer equations into a dimensionless form. The resulting nonlinear system is mapped to the vertical flat plate domain, and a non-similar solution is used to the obtained equations. The obtained non-similar system is then solved numerically using the fourth-order Runge-Kutta method. The influence of various physical parameters on the local Nusselt number, the local Sherwood number, the local density number of the motile microorganisms, the dimensionless velocity, the dimensionless temperature, and the rescaled density of motile microorganisms is studied. It is found that the local Nusselt number, the local Sherwood number, and the local density number of the motile microorganisms decrease by increasing either the Grashof number or the magnetic field parameter.展开更多
The phenomenon of wastewater discharged into coastal waters can be simplified as a turbulent jet under the effect of waves and currents. Previous studies have been carried out to investigate the jet behaviors under th...The phenomenon of wastewater discharged into coastal waters can be simplified as a turbulent jet under the effect of waves and currents. Previous studies have been carried out to investigate the jet behaviors under the current only or the wave only environment. To obtain better understanding of the jet behaviors in a realistic situation, a series of physical experiments on the initial dilution of a vertical round jet in the wavy cross-flow environment are conducted. The diluted processes of the jet are recorded by a high-resolution camcorder and the concentration fields of the jet are measured with a peristaltic suction pumping system. When the jet is discharged into the wavy cross-flow environment, a distinctive phenomenon, namely ＂effluent clouds＂, is observed. According to the quantitative measurements, the jet width in the wavy cross-flow environment increases more significantly than that does in the cross-flow only environment, indicating that the waves impose a positive effect on the enhancement of jet initial dilution. In order to generalize the experimental findings, a comprehensive velocity scale ua and a characteristic length scale l are introduced. Through dimensional analysis, it is found that the dimensionless centerline concentration trajectories cy/l is in proportion to 1/3 power of the dimensionless downstream distance x/l, and the dimensionless centerline dilution 2c aS Q/（u l） is proportional to the square of the dimensionless centerline trajectory cy/l. Several empirical equations are then derived by using the Froude number of cross-flow Frc as a reference coefficient. This paper provides a better understanding and new estimations of the jet initial dilution under the combined effect of waves and cross-flow current.展开更多
Numerical computation models of air cooling heat transfer and flow behaviors in triangular wavy fin channels(TWFC) were established with structural parameters of fins considered.The air side properties of heat transfe...Numerical computation models of air cooling heat transfer and flow behaviors in triangular wavy fin channels(TWFC) were established with structural parameters of fins considered.The air side properties of heat transfer coefficient and pressure drop are displayed with variable structural parameters of fins and inlet velocities of cooling air.Within the range of simulation,TWFC has the best comprehensive performance when inlet velocity vin=4-10 m/s.Compared with those of straight fins,the simulation results reveal that the triangular wavy fin channels are of higher heat transfer performances especially with the fin structural parameters of fin-height Fh=9.0 mm,fin-pitch Fp=2.5-3.0 mm,fin-wavelength λ=14.0-17.5 mm and fin-wave-amplitude A=1.0-1.2 mm.The correlations of both heat transfer factor and friction factor are presented,and the deviations from the experimental measurements are within 20%.展开更多
The main purpose of this study is to survey numerically comparison of two- phase and single phase of heat transfer and flow field of copper-water nanofluid in a wavy channel. The computational fluid dynamics （CFD） p...The main purpose of this study is to survey numerically comparison of two- phase and single phase of heat transfer and flow field of copper-water nanofluid in a wavy channel. The computational fluid dynamics （CFD） prediction is used for heat transfer and flow prediction of the single phase and three different two-phase models （mixture, volume of fluid （VOF）, and Eulerian）. The heat transfer coefficient, temperature, and velocity distributions are investigated. The results show that the differences between the temperature fie].d in the single phase and two-phase models are greater than those in the hydrodynamic tleld. Also, it is found that the heat transfer coefficient predicted by the single phase model is enhanced by increasing the volume fraction of nanoparticles for all Reynolds numbers; while for the two-phase models, when the Reynolds number is low, increasing the volume fraction of nanoparticles will enhance the heat transfer coefficient in the front and the middle of the wavy channel, but gradually decrease along the wavy channel.展开更多
Root system architecture is influenced by gravity.How the root senses gravity and directs its orientation,so-called gravitropism,is not only a fundamental question in plant biology but also theoretically important for...Root system architecture is influenced by gravity.How the root senses gravity and directs its orientation,so-called gravitropism,is not only a fundamental question in plant biology but also theoretically important for genetic improvement of crop root architecture.However,the mechanism has not been elucidated in most crops.We characterized a rice agravitropism allele,wavy root 1(war1),a loss-of-function allele in OsPIN2,which encodes an auxin efflux transporter.With loss of OsPIN2 function,war1 leads to altered root system architecture including wavy root,larger root distribution angle,and shallower root system due to the loss of gravitropic perception in root tips.In the war1 mutant,polar auxin transport was disrupted in the root tip,leading to abnormal auxin levels and disturbed auxin transport and distribution in columella cells.Amyloplast sedimentation,an important process in gravitropic sensing,was also decreased in root tip columella cells.The results indicated that OsPIN2 controls gravitropism by finely regulating auxin transport,distribution and levels,and amyloplast sedimentation in root tips.We identified a novel role of OsPIN2 in regulating ABA biosynthesis and response pathways.Loss of OsPIN2 function in the war1 resulted in increased sensitivity to ABA in seed germination,increased ABA level,changes in ABA-associated genes in roots,and decreased drought tolerance in the seedlings.These results suggest that the auxin transporter OsPIN2 not only modulates auxin transport to control root gravitropism,but also functions in ABA signaling to affect seed germination and root development,probably by mediating crosstalk between auxin and ABA pathways.展开更多
文摘1 Authorities in Montgomery Township,Pennsylvania,have introduced wavy lane patterns on some streets in an effort to slow down traffic in the area.2 Driving along Grays Lane in Montgomery Township for the first time must be challenging.Thats because the regular lane patterns have been replaced by wavy and zig⁃zag lines that look like they were painted by a drunk.But they are wavy by design.According to Montgomery Township officials,the unusual patterns were thought as the best solution to discouraging speeding on some of the streets.Police sources told local media outlets that the“traffic⁃calming measures”were installed in response to numerous complaints about certain streets being used as“speedways”.
基金supported by the National Natural Science Foundation of China(Grant No.12272369)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0620101).
文摘In recent decades,capacitive pressure sensors(CPSs)with high sensitivity have demonstrated significant potential in applications such as medical monitoring,artificial intelligence,and soft robotics.Efforts to enhance this sensitivity have predominantly focused on material design and structural optimization,with surface microstructures such as wrinkles,pyramids,and micro-pillars proving effective.Although finite element modeling(FEM)has guided enhancements in CPS sensitivity across various surface designs,a theoretical understanding of sensitivity improvements remains underexplored.This paper employs sinusoidal wavy surfaces as a representative model to analytically elucidate the underlying mechanisms of sensitivity enhancement through contact mechanics.These theoretical insights are corroborated by FEM and experimental validations.Our findings underscore that optimizing material properties,such as Young’s modulus and relative permittivity,alongside adjustments in surface roughness and substrate thickness,can significantly elevate the sensitivity.The optimal performance is achieved when the amplitude-to-wavelength ratio(H/)is about 0.2.These results offer critical insights for designing ultrasensitive CPS devices,paving the way for advancements in sensor technology.
基金supported by the National Natural Science Foundation of China(12322210,12172351,92252202,and 12388101)the Fundamental Research Funds for the Central Universities.
文摘Rod-airfoil interaction noise becomes a major issue in some aeronautical applications.The design of four wavy leading edges(WLEs)with varying wavelengths,bioinspired by the tubercles on humpback whales’flippers,aims to mitigate far-field noise.Among these cases,a reduction in the wavelength is found to be advantageous for noise suppression,with the smallest wavelength case achieving a maximum noise reduction of 1.9 dB.Furthermore,the noise radiation induced by WLEs is suppressed mainly at medium frequencies.The theory of multiprocess aeroacoustics is applied to reveal their underlying mechanisms.The dominant factor is the source cutoff effect,which significantly decreases the source strength on hills.Additionally,spanwise decoherence with phase interference serves as another crucial mechanism,particularly for reducing mid-frequency noise.
文摘This study evaluates the physical mechanisms of incident waves as they interact with a porous wavy barrier of finite thickness.A wave-trapping chamber is formed between the thick wavy barrier(TWB)and partially reflecting seawall(PRS).The effect of seabed undulations is incorporated into the wave-trapping analysis of the TWB.The boundary value problem proposed in this study is solved using a multidomain boundary element method within the context of linear potential flow theory.Coefficients such as reflection,runup,horizontal force on PRS,and vertical force on TWB are examined for various structural configurations.The position of seabed undulations is analyzed for four scenarios:i)seabed undulations upwave of the wavy barrier with a trapping chamber,ii)seabed undulations upwave of the wavy barrier without a trapping chamber,iii)seabed undulations underneath the wavy barrier with a trapping chamber,and iv)seabed undulations beneath the wavy barrier without a trapping chamber.The study results are compared with known results to verify their accuracy.The effects of PRS,TWB porosity,trapping chamber,plate thickness,seabed type,and submergence depth on hydrodynamic coefficients are analyzed against relative water depth.The study reveals that the introduction of a porous TWB with a trapping chamber results in minimal hydrodynamic coefficients(reduced reflection and force on a wall)compared to a rigid TWB without a trapping chamber.A comparison of various seabeds is reported for all combinations of TWB with a chamber.The sloping seabed upwave of the barrier with a trapping chamber,20%plate porosity,and 50%wall reflection at an appropriate submergence depth could replace gravity-type breakwaters in deeper waters.This study holds great potential for analyzing wave trapping coefficients by TWB to provide an effective coastal protection system.
基金supported by the National Key Research and Development Program of China(2023YFD2303302,2022YFD2300803)the National Natural Science Foundation of China(32160445)the China Agriculture Research System of MOF and MARA(CARS-02-16).
文摘High-density planting increases maize yield but also canopy crowding and stalk lodging.Aiming this contradiction,a wavy canopy was created using interlaced chemical application(IC)of a plant growth retardant at the V14 stage with three densities(60,000,75,000,and 90,000 plants ha-1,indicated by D1,D2,and D3,respectively)for two seasons.The results showed that the IC-treated wavy canopy featuring both natural height(IC-H)and dwarfed(IC-L)plants,improved light transmission by 8.54%,8.49%,and 16.49%on average than the corresponding controls(CK)at D1,D2,and D3,respectively.The alleviation of canopy crowding stimulated leaf photosynthesis,sugar availability,basal-internode strength,and decreased plant lodging ratios in both IC-H and IC-L,particularly under higher densities.Meanwhile,the IC populations produced significantly higher yield than CK,with an average increase of 3.38%,16.70%,and 15.28%at D1,D2,and D3,respectively.Collectively,this study proposed a new wavy canopy strategy using plant growth retardant to simultaneously increase yield performance and lodging resistance,thus offering a sustainable solution for further development of high-density maize production.
基金supported by the Technology Project of CNPC(Grant No.2023ZZ08)the National Natural Science Foundation of China(Grant No.52274058)the USTC Research Funds of the Double First-Class Initiative(Grant No.YD2090002025).
文摘Shale reservoirs have abundant bedding structures,which deeply alter the mechanical properties of rocks,and thus affect the reservoir stimulation performance.Previous research mostly focuses on the effects of parallel bedding on fracture propagation,while the mechanical properties and mechanisms of fracture propagation remain unclear for rocks with complex wavy bedding(e.g.China’s continentalorigin Gulong shale).Herein,a mixed phase-field fracture model of the wavy-bedding shale was applied,based on the local tension-compression decomposition phase field method(PFM)and geometric structure generation algorithm for the bedding with controllable morphological features.The parametric analysis of fracture propagation behaviors in the case of abundant complex bedding structures showed that with wavy bedding,the vertical fracture propagation rate is far higher than the horizontal propagation rate.Moreover,the development of branch fractures is suppressed during the fracturing process of the wavy-bedding sample,and the stimulated volume is limited,which is different from the characteristic of parallel bedding that promotes horizontal fracture initiation and propagation.The results showed that larger amplitudes,higher frequencies,higher inclination angles,and larger strengths of wavy bedding all promote the formation of vertical penetrating fractures and suppress the growth of branch fractures.Under such circumstances,it is hard to create a well-connected fracture network after fracturing.This research may provide a theoretical basis for understanding fracture behaviors in rocks with such complex wavy bedding.
基金support from the National Natural Science Foundation of China(Nos.12372256,12072186).
文摘The noise generated by subsonic jet nozzles, commonly encountered in civilian aircraft, is rather significant and propagates in both the upstream and downstream directions due to large-scale and fine-scale turbulence structures. In this paper, a distinctive inner wall treatment strategy, denoted as the Azimuthally-distributed Wavy Inner Wall (AWIW), is proposed, which is aimed at mitigating jet noise. Within this strategy, a circumferentially dispersed treatment wall characterized by a minute wavy pattern is substituted for the smooth inner wall in proximity to the nozzle outlet. To assess the effectiveness of the AWIW treatment, we conducted numerical simulations. The unsteady flow field and far-field noise were predicted by employing Large Eddy Simulations (LES) coupled with the Ffowcs Williams and Hawkings (FW-H) integration method. To gain a comprehensive understanding of the mechanism underlying the noise reduction facilitated by the AWIW treatment, it examined physical parameters such as the Lighthill source acoustic source term, the turbulent kinetic energy acoustic source term, and the shear layer instability. The results reveal that the AWIW treatment expedites the instability within the shear layer of the jet, leading to an early disruption of the jet shear layer, and consequently turbulent structures in varying sizes are generated downstream. This process effectively regulates the generation and emission of jet noise. By controlling the minor scale turbulence through the AWIW treatment, the mid- and high-frequency noise within the distant field can be significantly reduced. In the context of the flow field, the introduction of AWIW also leads to a decrease in drag on the inner wall surface of the jet, thereby improving the overall aerodynamic performance of the nozzle. Considering these attributes, the AWIW strategy emerges as a viable technique for the reduction of jet noise.
文摘This study involved numerical simulations of a double tube heat exchanger using the ANSYS FLUENT programversion 22.The study aims to examine methods for minimizing pressure loss and consequently enhancing the thermal performance index(TPI)of a heat exchanger fitted with wavy edge tape that is a heat recovery system(the hot air in simulation instead of t heat from the exhaust gases of the brick factory furnaces and return it to warm the heavy fuel oil by substituting the electrical heater with a heat exchanger to recuperate waste heat from the flue gases,so elevating the temperature of Heavy fuel oil(HFO)to inject from the roof nozzles of combustion chamber of the furnace furthermore reducing cost(by finding the optimal design of wavy edge tape))and energy consumption.Air was selected as the hot gas in the inner pipe instead of furnace exhaust gases due to their similar thermal characteristics.A numerical analysis was conducted to create a novel wavy edge tape with varying widths(50%Di,75%Di,and 95%Di),lengths(1000,1200,1400)mm,amplitudes(5,10,15)mm,and periods of wavy length(5,10,15)mm.The flow rate of the outer pipe fluid(oil)ranges from(0.06 to 0.1)kg/s,while the velocity of the hot fluid(air)varies from(1 to 27)m/s,Re_(air)(6957 to 187,837).The entrance temperature of the hot fluid can be either(200,225,and 250)℃.The study finds that wavy edge tape tubes are more effective than smooth tubes in terms of oil outlet temperature;results revealed that an increase in the oil mass flow rate leads to a decrease in the oil outlet temperature and an increase in the heat transfer rate,at the air temperature 250℃.Additionally,the results indicate that increasing the width,length,and amplitude also leads to an increase in the oil outlet temperature of(94-94.12)℃,the pressure drop of(568.3)Pa,and the Nusselt number(65.7-66.5)respectively on the oil side.Finally,the heat exchanger’s best thermal performance index was found by investigating temperature contour at amplitude(A=5),period(p=15),width(w=75%Di),and length(L=1200 mm).The values for these parameters are,in order(1.02,1.025,1.02,and 1.0077).
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12375250,11875121,51977057,11805013)the Natural Science Foundation of Hebei Province,China(Grant Nos.A2020201025 and A2022201036)+3 种基金the Hebei Province Optoelectronic Information Materials Laboratory Performance Subsidy Fund Project(Grant No.22567634H)the Funds for Distinguished Young Scientists of Hebei Province,China(Grant No.A2012201045)the Natural Science Interdisciplinary Research Program of Hebei University(Grant Nos.DXK201908 and DXK202011)the Post-graduate’s Innovation Fund Project of Hebei University(Grant No.HBU2022bs004)。
文摘As a popular approach to producing atmospheric pressure non-thermal plasma,dielectric barrier discharge(DBD)has been extensively used in various application fields.In this paper,DBD with wavy dielectric layers is numerically simulated in atmospheric pressure helium mixed with trace nitrogen based on a fluid model.With varying relative position(phase difference(Δφ))of the wavy surfaces,there is a positive discharge and a negative discharge per voltage cycle,each of which consists of a pulse stage and a hump stage.For the pulse stage,maximal current increases with increasingΔφ.Results show that DBD with the wavy surfaces appears as discrete micro-discharges(MDs),which are self-organized to different patterns with varyingΔφ.The MDs are vertical and uniformly-spaced withΔφ=0,which are self-organized in pairs withΔφ=π/4.These MD pairs are merged into some bright wide MDs withΔφ=π/2.In addition,narrow MDs appear between tilted wide MDs withΔφ=3π/4.WithΔφ=π,the pattern is composed of wide and narrow MDs,which are vertical and appear alternately.To elucidate the formation mechanism of the patterns with differentΔφ,temporal evolutions of electron density and electric field are investigated for the positive discharge.Moreover,surface charge on the wavy dielectric layers has also been compared with differentΔφ.
基金the Deanship of Scientific Research at Umm Al-Qura University for supporting this work through Grant Code:22UQU4240002DSR19.
文摘The goal of this paper is to represent a numerical study of magnetohydrodynamic mixed convection heat transfer in a lid-driven vertical wavy enclosure with a fin attached to the bottomwall.We use a finite elementmethod based on Galerkin weighted residual(GWR)techniques to set up the appropriate governing equations for the present flow model.We have conducted a parametric investigation to examine the impact of Hartmann and Richardson numbers on the flow pattern and heat transmission features inside a wavy cavity.We graphically represent the numerical results,such as isotherms,streamlines,velocity profiles,local and mean Nusselt numbers,and average surface temperature.Comparisons between the results of this work and previously published work in a literature review have been produced to examine the reliability and consistency of the data.The different sizes of the fin surface significantly impact flow creation and temperature fields.Additionally,the long fin size is necessary to enhance the heat transfer rate on the right surface at large Richardson numbers and low Hartmann numbers.Fin surfaces can significantly increase the mixing of fluid inside the enclosure,which can mean reductions in reaction times and operating costs,along with increases in heat transfer and efficiency.
基金funding this research work through the project number“NBU-FFR-2024-2505-08”.
文摘In this paper,the unsteady magnetohydrodynamic(MHD)-radiation-natural convection of a hybrid nanofluid within a U-shaped wavy porous cavity is investigated.This problem has relevant applications in optimizing thermal management systems in electronic devices,solar energy collectors,and other industrial applications where efficient heat transfer is very important.The study is based on the application of a numerical approach using the Finite Difference Method(FDM)for the resolution of the governing equations,which incorporates the Rosseland approximation for thermal radiation and the Darcy-Brinkman-Forchheimer model for porous media.It was found that the increase of Hartmann number(Ha)causes a reduction of the average Nusselt number(Nu),with a maximum decrease of 25%observed as Ha increases from 0 to 50.In addition,the influence of the wall’s wave amplitude and the heat source length on the heat transfer rate was quantified,and it was revealed that at high wave amplitude,the average Nu increases by up to 15%.These findings suggest that manipulating magnetic field strength and cavity geometry can significantly enhance thermal performance.The novelty of this is related to the exploration of a U-shaped wavy cavity,which is not covered in previous studies,and to the detailed examination of the combined effects of magnetic fields,radiation,and hybrid nanofluids.
基金supported by the National Natural Science Foundation of China (Nos.51776174,51476134,51276149 and 11602290)State Key Laboratory of Aerodynamics of China Aerodynamics Research and Development Center (No.SKLA20160201)+1 种基金Key Laboratory of Aerodynamic Noise Control of China Aerodynamics Research and Development Center (No.ANCL20170201)China-Europe IMAGE (Innovative Methodologies and Technologies for Reducing Aircraft Noise Generation and Emission) program (No.688971-IMAGE-H2020MG-20141015)
文摘Large Eddy Simulation（LES） is performed to investigate the airfoil broadband noise reduction with wavy leading edge under anisotropic incoming turbulence. The anisotropic incoming turbulence is generated by a rod with a diameter of 10 mm. The incoming flow velocity is 40 m/s and the corresponding Reynolds numbers based on airfoil chord and rod diameter are about 397000 and 26000, respectively. The far-field acoustic field is predicted using an acoustic analogy method which has been validated by the experiment. A straight leading edge airfoil and a wavy leading edge airfoil are simulated. The results show that wavy leading edge increases the airfoil lift and drag whereas the lift and drag fluctuations are substantially reduced. In addition, wavy leading edge can significantly change the flow pattern around the leading edge and a pair of counter-rotating streamwise vortices stemming from each wavy leading edge peak are observed.An averaged noise reduction of 9.5 dB is observed with the wavy leading edge at the azimuthal angle of 90°. Moreover, the wavy leading edge can mitigate noise radiation at all the azimuthal angles without significantly changing the noise directivity. The underlying noise reduction mechanisms are then analyzed in detail.
基金supported by the National Basic Research Program of China (2009CB724104)the National Natural Science Foundation of China (90716010)
文摘The Xu ＆ Yan scale-adaptive simulation （XYSAS） model is employed to simulate the flows past wavy cylinders at Reynolds number 8 × 10 3.This approach yields results in good agreement with experimental measurements.The mean flow field and near wake vortex structure are replicated and compared with that of a corresponding circular cylinder.The effects of wavelength ratios λ/D m from 3 to 7,together with the amplitude ratios a /D m of 0.091 and 0.25,are fully investigated.Owing to the wavy configuration,a maximum reduction of Strouhal number and root-meansquare （r.m.s） fluctuating lift coefficients are up to 50% and 92%,respectively,which means the vortex induced vibration （VIV） could be effectively alleviated at certain larger values of λ/D m and a /D m.Also,the drag coefficients can be reduced by 30%.It is found that the flow field presents contrary patterns with the increase of λ/D m.The free shear layer becomes much more stable and rolls up into mature vortex only further downstream when λ/D m falls in the range of 5-7.The amplitude ratio a /D m greatly changes the separation line,and subsequently influences the wake structures.
基金the National Natural Science Foundation of China(No. 10772119)
文摘In this paper,a numerical simulation of flow-induced noise by the low Mach number turbulent flow with a sinusoidal wavy wall was presented based on the unsteady incompressible Navier-Stokes equations and Lighthill's acoustic analogy.Large eddy simulation (LES) was used to investigate the space-time flow field and the Smagorinsky sub-grid scale (SGS) model was introduced for turbulence model.Using Lighthill's acoustics analogy,the flow field simulated by LES was taken as near-field sound sources and radiated sound from turbulent flow was computed by the Curle's integral formulation under the low Mach number approximation.Both spanwise wavy wall and streamwise wavy wall with various wall wave amplitudes were discussed to investigate their effects on reducing the drag and flow noise.The relationship between flow noise and drag on the wavy wall is also studied.
文摘As reported in a previous work by Lin et al.(Acta Meeh Sin, 2018. https://doi.org/10.1007/s 10409-018-0758-z), an interesting phenomenon was discovered based on the analysis of wavy vortex and vorticity distribution in the shear layers and near wake of a peak-perforated conic shroud, and two sign laws were summarized. In the present paper, the theory of a vortex-induced vortex is introduced to explore mechanisms in a wavy vortex and applicable sign laws for uniform and incompressible flow past a fixed bluff body. Based on the analysis of the nearest-wall How, two vortex-induced models for streamwise and vertical vortex pairs, respectively, are proposed under two boundary cases, denoting the induced vorticity introduced or distributed on and near the walls. As a result, the first sign law, for only streamwise and vertical components of vorticity, and the second sign law, for three components of vorticity, are obtained under their own particular conditions. The first sign law reveals the intrinsic physical relationship between streamwise and vertical vorticities, independent of the distribution of spanwise vortices in the whole flow field. It is also confirmed that the spanwise vortices, as well as the shear layers and wake width, distributed wavily across the span, are attributed to the introduced streamwise or vertical vortices. The two sign laws for vorticity are independent of the disturbed spanwise wavelength and the Reynolds number. Through the analysis of flow past the conic shroud, the two sign laws are successfully used to summarize typical spacial distributions of vorticity in three flow regions: on and near the front cylinder surfaces, the separated shear layers and the near wake.
文摘Magnetohydrodynamic （MHD） bioconvection of an incompressible electrically conducting nanofluid near a vertical wavy surface saturated porous medium containing both nanoparticle and gyrotactic microorganisms is investigated. The nanofluid is represented by a model that includes both Brownian motion and thermophoresis effects. A suitable set of non-dimensional variables are used to transform the governing boundary layer equations into a dimensionless form. The resulting nonlinear system is mapped to the vertical flat plate domain, and a non-similar solution is used to the obtained equations. The obtained non-similar system is then solved numerically using the fourth-order Runge-Kutta method. The influence of various physical parameters on the local Nusselt number, the local Sherwood number, the local density number of the motile microorganisms, the dimensionless velocity, the dimensionless temperature, and the rescaled density of motile microorganisms is studied. It is found that the local Nusselt number, the local Sherwood number, and the local density number of the motile microorganisms decrease by increasing either the Grashof number or the magnetic field parameter.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51379072 and 51309092)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20120094110016)+1 种基金the‘111’Project of the Ministry of Education and the State Administration of Foreign Experts AffairsChina(Grant No.B12032)
文摘The phenomenon of wastewater discharged into coastal waters can be simplified as a turbulent jet under the effect of waves and currents. Previous studies have been carried out to investigate the jet behaviors under the current only or the wave only environment. To obtain better understanding of the jet behaviors in a realistic situation, a series of physical experiments on the initial dilution of a vertical round jet in the wavy cross-flow environment are conducted. The diluted processes of the jet are recorded by a high-resolution camcorder and the concentration fields of the jet are measured with a peristaltic suction pumping system. When the jet is discharged into the wavy cross-flow environment, a distinctive phenomenon, namely ＂effluent clouds＂, is observed. According to the quantitative measurements, the jet width in the wavy cross-flow environment increases more significantly than that does in the cross-flow only environment, indicating that the waves impose a positive effect on the enhancement of jet initial dilution. In order to generalize the experimental findings, a comprehensive velocity scale ua and a characteristic length scale l are introduced. Through dimensional analysis, it is found that the dimensionless centerline concentration trajectories cy/l is in proportion to 1/3 power of the dimensionless downstream distance x/l, and the dimensionless centerline dilution 2c aS Q/（u l） is proportional to the square of the dimensionless centerline trajectory cy/l. Several empirical equations are then derived by using the Froude number of cross-flow Frc as a reference coefficient. This paper provides a better understanding and new estimations of the jet initial dilution under the combined effect of waves and cross-flow current.
基金Project(50976022) supported by the National Natural Science Foundation of ChinaProject(BY2011155) supported by the Provincial Science and Technology Innovation and Transformation of Achievements of Special Fund Project of Jiangsu Province,China
文摘Numerical computation models of air cooling heat transfer and flow behaviors in triangular wavy fin channels(TWFC) were established with structural parameters of fins considered.The air side properties of heat transfer coefficient and pressure drop are displayed with variable structural parameters of fins and inlet velocities of cooling air.Within the range of simulation,TWFC has the best comprehensive performance when inlet velocity vin=4-10 m/s.Compared with those of straight fins,the simulation results reveal that the triangular wavy fin channels are of higher heat transfer performances especially with the fin structural parameters of fin-height Fh=9.0 mm,fin-pitch Fp=2.5-3.0 mm,fin-wavelength λ=14.0-17.5 mm and fin-wave-amplitude A=1.0-1.2 mm.The correlations of both heat transfer factor and friction factor are presented,and the deviations from the experimental measurements are within 20%.
文摘The main purpose of this study is to survey numerically comparison of two- phase and single phase of heat transfer and flow field of copper-water nanofluid in a wavy channel. The computational fluid dynamics （CFD） prediction is used for heat transfer and flow prediction of the single phase and three different two-phase models （mixture, volume of fluid （VOF）, and Eulerian）. The heat transfer coefficient, temperature, and velocity distributions are investigated. The results show that the differences between the temperature fie].d in the single phase and two-phase models are greater than those in the hydrodynamic tleld. Also, it is found that the heat transfer coefficient predicted by the single phase model is enhanced by increasing the volume fraction of nanoparticles for all Reynolds numbers; while for the two-phase models, when the Reynolds number is low, increasing the volume fraction of nanoparticles will enhance the heat transfer coefficient in the front and the middle of the wavy channel, but gradually decrease along the wavy channel.
基金supported by the National Natural Science Foundation of China(32070197,31570181 and 31200148)Chinese Universities Scientific Fund(2452018149)。
文摘Root system architecture is influenced by gravity.How the root senses gravity and directs its orientation,so-called gravitropism,is not only a fundamental question in plant biology but also theoretically important for genetic improvement of crop root architecture.However,the mechanism has not been elucidated in most crops.We characterized a rice agravitropism allele,wavy root 1(war1),a loss-of-function allele in OsPIN2,which encodes an auxin efflux transporter.With loss of OsPIN2 function,war1 leads to altered root system architecture including wavy root,larger root distribution angle,and shallower root system due to the loss of gravitropic perception in root tips.In the war1 mutant,polar auxin transport was disrupted in the root tip,leading to abnormal auxin levels and disturbed auxin transport and distribution in columella cells.Amyloplast sedimentation,an important process in gravitropic sensing,was also decreased in root tip columella cells.The results indicated that OsPIN2 controls gravitropism by finely regulating auxin transport,distribution and levels,and amyloplast sedimentation in root tips.We identified a novel role of OsPIN2 in regulating ABA biosynthesis and response pathways.Loss of OsPIN2 function in the war1 resulted in increased sensitivity to ABA in seed germination,increased ABA level,changes in ABA-associated genes in roots,and decreased drought tolerance in the seedlings.These results suggest that the auxin transporter OsPIN2 not only modulates auxin transport to control root gravitropism,but also functions in ABA signaling to affect seed germination and root development,probably by mediating crosstalk between auxin and ABA pathways.
