Fruit colour is essential to seed dispersal,speciation,and biological diversity in global ecosystems.The relationship between fruit-colour variation and species diversification has long been of interest in evolutionar...Fruit colour is essential to seed dispersal,speciation,and biological diversity in global ecosystems.The relationship between fruit-colour variation and species diversification has long been of interest in evolutionary biology,but remains poorly understood at the genus level.Here,we used Callicarpa,a typical representative of pantropical angiosperm,to analyse whether fruit colours are correlated with biogeographic distribution,dispersal events,and diversification rate.We estimated a time-calibrated phylogeny for Callicarpa and reconstructed ancestral fruit colour.Utilizing phylogenetic methods,we estimated the major dispersal events across the phylogenetic tree and the most likely fruit colours related to each dispersal event,and tested whether the dispersal frequencies and distances of the four fruit colours between major biogeographical areas were equal.We then tested whether fruit colours are correlated with latitude,elevation,and diversification rate.Biogeographical reconstructions showed that Callicarpa originated in the East Asia and Southeast Asia during the Eocene(-35.53 Ma) and diverse species diverged mainly in the Miocene and lasted into the Pleistocene.Large-scale dispersal events were significantly associated with violet-fruited lineages.Furthermore,different fruit colours were markedly correlated with different latitudes and elevations(e.g.,violet fruits were correlated with higher latitudes and elevations;red fruits and black fruits with lower latitudes;white fruits with higher elevations).Notably,violet fruits were statistically associated with highest diversification rates,driving fruit colour variation among different regions globally.Our results contribute to further understanding why fruit colour is so variable at the genus level of angiosperms in different areas around the world.展开更多
Dahurian larch growing in Daxing’an Mountains can be divided into two types according to the wood colour: one is red, the other is white. Based on the national standard of the "Testing methods for physical &...Dahurian larch growing in Daxing’an Mountains can be divided into two types according to the wood colour: one is red, the other is white. Based on the national standard of the "Testing methods for physical &mechanical properties of wood", the parameters of wood colour and physico-mechanical properties of the above two different woods were tested and analyzed.The result showed that the colour rational phenetic parameters, physico-mechanical properties and work abilities of thc two woods were quite different, combincd with the other morphological characteristics, they belong to intraspccific two different types of Dahurian larch. The white wood is superior to the red one as a valuable timber tree. Because the cocfficients of shrinkage, hardness and colour of both are different, they were mixed working in the past, inevitably there have been various defects in working. In order to overcome these defects, we propose that the departments of wood production, salesmen and consumers should use them differently according to their individual character.展开更多
The role of bare body parts in sexual signalling in birds has received relatively little attention.I describe how the bare-throated spurfowl males saturate the colours of their throats to attract females.Of the 23 Afr...The role of bare body parts in sexual signalling in birds has received relatively little attention.I describe how the bare-throated spurfowl males saturate the colours of their throats to attract females.Of the 23 Afrotropical spurfowl species,the bare-throated subgroup includes Yellow-necked Spurfowl(Pternistis leucosceptus),Rednecked Spurfowl(P.afer),Grey-breasted Spurfowl(P.rufopictus) and Swainson’s Spurfowl(P.swainsonii).The rest of the species include fully feathered throated spurfowls.Throat colour intensity of bare throats was scored using an extensive online digital photographic archive encompassing the four species across the year’s seasons.Each throat(n=836) was assigned to one of four colour-intensity categories to explore the relationship between colour intensities,breeding cycles,and environmental variation.Except for Swainson’s Spurfowl male saturation of throat colours correlated with monthly rainfall,which peaks one or two months before egg laying.Swainson’s Spurfowl peaks during egg laying.Yellow-necked Spurfowl has the largest bare throat.Bare-throated spurfowl males perform an elevated courtship display posture above the female to feature their throat colour.No such displays occur in feather-throated spurfowl.Males with low throat colour saturation harbour more ectoparasites on their bare throats than birds with saturated throats.Male Red-necked Spurfowls have significantly larger bare throats than females.The primary function of bare throats probably assists in thermoregulation,particularly in arid regions.The bare throat may have evolved a secondary role in mating.Yellow-necked,Red-necked,and Greybreasted Spurfowls use their saturated throat colours as ornaments to court females during the breeding season.Unobtrusive female throat colours(unsaturated) may discourage male interlopers and predation during egg laying.Saturation appears to be carotenoid-food based.The different colours among the bare-throated species may serve as prezygotic mechanisms that inhibit cross-breeding and explain why females also have coloured throats.展开更多
AIM:To compare the Ishihara test errors scores of colour vision deficiency(CVD)subjects when wearing four different types of red-tinted contact lenses(RCL)that differ in their transmittance as determined using a spect...AIM:To compare the Ishihara test errors scores of colour vision deficiency(CVD)subjects when wearing four different types of red-tinted contact lenses(RCL)that differ in their transmittance as determined using a spectrophotometer.METHODS:Six congenital CVD subjects volunteered to participate in this study.Ishihara plates were used to determine the colour vision errors made,whereas Farnsworth-Munsell 100 Hue test was conducted to determine the total error scores(TES)and type of CVD.Four types of RCL(Types A,B,C and D)were inserted in the non-dominant eye and tested in a randomised manner by a masked operator.Errors scores in Ishihara test were determined at baseline without any contact lens and after wearing the four different RCL.The subjects were then divided into two groups based on the mean TES.RESULTS:Repeated measures ANOVA with Greenhouse-Geisser corrections showed that there was a highly significant effect of RCL type on Ishihara error score[F(2.056,10.282)=30.214,P<0.001].Error scores with RCL Type B were significantly lower than errors made when no lens was worn,and with RCL Type C and Type D(all P<0.001).Error scores with RCL Type B were also lower than those made with RCL Type A,however,they were not significantly different.For subjects with TES values less than 180,RCL type B showed the largest improvement in Ishihara error score(50%)compared to the other three RCLs.RCL type A showed the best performance in TES value of more than 180,with an improvement of 80%in Ishihara score.RCL Type A has the lowest transmittance at the confusion wavelength(450-568 nm),followed by RCL Types B,D and C.CONCLUSION:This study shows that RCL can improve Ishihara error scores.RCL with lower transmission at 450-568 nm and 90%transmittance beyond 637 nm are the most effective.Lenses which could block more light between 550-580 nm are more effective for colour defectives with more severe colour defects.展开更多
Quantitative analysis of colouration is an essential tool for subspecies delimitation but has always posed a challenge in avian taxonomy.In this study on the Chestnut-winged Babbler(Cyanoderma erythropterum)species co...Quantitative analysis of colouration is an essential tool for subspecies delimitation but has always posed a challenge in avian taxonomy.In this study on the Chestnut-winged Babbler(Cyanoderma erythropterum)species complex from tropical Southeast Asia,we made use of colour measurements taken with digital cameras and applied two methodologies—(1)the 75%subspecies rule on quantitative colourimetric variables,and(2)the CIEDE2000 colour distance method to generate phylograms,which has probably never been applied in taxonomy before.Given its large number of described subspecies,many of which have been synonymised in modern taxonomies,the species complex serves as an appropriate model to test subspecies validity.Our data indicate that one synonymised subspecies(C.e.apega),from the islands of Bangka and Belitung,requires re-instalment and recognition,whereas one widely recognised subspecies(C.e.fulviventre),from the Banyak Islands,should be synonymised.Our approach also allowed us to redraw geographic subspecies boundaries.Our work indicates that current subspecies taxonomies of many poorly known tropical species may remain error-ridden and highlights the importance and viability of large-scale taxonomic revisions targeting avian subspecies globally while incorporating quantitative colourimetric approaches.展开更多
This work presents a grounding protection system of the central solenoid model coil(CSMC)of the Comprehensive Research Facility for Fusion Technology(CRAFT).The scheme of neutral point voltage detections has been adop...This work presents a grounding protection system of the central solenoid model coil(CSMC)of the Comprehensive Research Facility for Fusion Technology(CRAFT).The scheme of neutral point voltage detections has been adopted in grounding protection system.Compared with the usual current acquisition,the measurement data is accurate,there is no redundant loop,and the economic benefit is high.In this study,the single-end and double-end grounding fault protections of superconducting magnet coil are analyzed,and the fault voltage and current under different fault conditions are calculated.The simulation model of CSMC magnet grounding fault is established,and the simulation results of the model are basically consistent with the theoretical calculation.Finally,a small capacity experiment platform is used to verify the function of the grounding protection system.The experimental results show that by comparing the neutral fault sampling voltage with the theoretical grounding protection threshold,the grounding protection system can effectively detect different types of grounding faults and transmit signals to the control system to protect the coils of superconducting magnets.展开更多
The negative ion based neutral beam injector(NNBI)with a beam energy of 400 keV is one of the subsystems at the Comprehensive Research fAcility for Fusion Technology(CRAFT)in China.The distributed capacitance of the h...The negative ion based neutral beam injector(NNBI)with a beam energy of 400 keV is one of the subsystems at the Comprehensive Research fAcility for Fusion Technology(CRAFT)in China.The distributed capacitance of the high-voltage components is an important basis for the design of surge suppression devices at CRAFT NNBI.This study conducted calculations of distributed capacitance for the key components,including the high-voltage deck,transmission line and isolation transformer in the power supply system using the finite element method.The relationship between the high-voltage deck(HVD)distributed capacitance and the distance from the wall is discussed.The differences in distributed capacitance and energy storage between noncoaxial and coaxial transmission lines are also debated.Finally,the capacitance between the primary and secondary windings of the-400 kV isolation transformer,as well as between the secondary winding and the oil tank casing,was calculated.展开更多
The electromagnetic turbulence in reversed field pinch(RFP)plasmas exhibits three-dimensional characteristics.Suppression of this turbulence is crucial for enhancing plasma confinement,necessitating control over the e...The electromagnetic turbulence in reversed field pinch(RFP)plasmas exhibits three-dimensional characteristics.Suppression of this turbulence is crucial for enhancing plasma confinement,necessitating control over the electric field or the current profile.To this end,two sets of electrodes have been designed and installed on the Keda Torus eXperiment(KTX)RFP device to manipulate the edge electric field and the edge parallel current profile.Subsequently,the edge radial electric field and edge parallel current profile control experiments are conducted.In the edge radial electric field control experiments,the edge radial electric field is altered under bias,accompanied with an increase in the electron density and plasma duration.However,under bias,both electrostatic and magnetic fluctuations are enhanced.In the edge parallel current profile control experiments,the results indicate that bias modifies the edge parallel current profile locally,leading to a localized increase in the field reversal depth and electron density.Additionally,a reduction in magnetic fluctuations is observed within the reversed field enhanced region under bias,suggesting that the bias suppresses magnetic perturbations.展开更多
When discharge faults occur in dry air switchgear,the air decomposes to produce diverse gases,with NO_(2) reaching the highest levels.Detecting the NO_(2) level can reflect the operation status of the equipment.This p...When discharge faults occur in dry air switchgear,the air decomposes to produce diverse gases,with NO_(2) reaching the highest levels.Detecting the NO_(2) level can reflect the operation status of the equipment.This paper proposes to combine ZnO cluster with MoS_(2) to improve the gassensitive properties of the monolayer.Based on the Density Functional Theory(DFT),the effect of(ZnO)n size on the behavior of MoS_(2 )is considered.Key parameters such as adsorption energy and band gap of(ZnO)n-MoS_(2)/NO_(2) system were calculated.The ZnO-MoS_(2) heterojunction was successfully synthesized by a hydrothermal method.The gas sensor exhibits a remarkable response and a fast response-recovery time to 100 ppm NO_(2).In addition,it demonstrates excellent selectivity,long-term stability and a low detection limit.This work confirms the potential of the ZnO-MoS_(2) composite structure as a highly effective gas sensor for NO_(2) detection,which provides valuable theoretical and experimental insights for fault detection in dry air switchgear.展开更多
The EHL-2 spherical torus at ENN is the next-generation experimental platform under conceptual design,aiming at realizing proton-boron(p-^(11)B)thermonuclear fusion,which is an attractive pathway towards neutron-free ...The EHL-2 spherical torus at ENN is the next-generation experimental platform under conceptual design,aiming at realizing proton-boron(p-^(11)B)thermonuclear fusion,which is an attractive pathway towards neutron-free fusion.To achieve high-performance steady-state plasma,it is extremely necessary to study the turbulence transport characteristics with high boron content in the plasma core.This study investigates the transport properties in the core internal transport barrier(ITB)region of p-^(11)B plasma utilizing the gyrokinetic code GENE in view of the high ion temperature scenario of EHL-2,specifically focusing on the impact of boron fractions and plasmaβon the microinstabilities and corresponding transport features.Numerical findings indicate that the inclusion of boron species effectively suppresses the trapped electron modes(TEMs)as well as promoting a transition from electromagnetic to electrostatic turbulence with increased boron fraction,which is a result of the suppression of microinstabilities by effective charge and mass.Moreover,it has been identified that the external E×B rotational shear has a notable inhibitory influence on transport,which can reduce the transport level by two to three orders of magnitude,especially at medium boron content.The suppressive effect of E×B on turbulence is weakened once the kinetic ballooning mode(KBM)is excited and the transport shows a rapid increase withβtogether with a reduction in zonal flow amplitude,which is consistent with previous findings.Therefore,it is strongly suggested that exploring advanced strategies for mitigating turbulent transport at highβregimes is necessary for the active control of plasma behavior regarding p-^(11)B plasma-based fusion devices such as EHL-2.展开更多
In this study,we explored a one-step direct synthesis of NH3 under mild experimental conditions utilizing pulse-modulated microwave plasma technology at atmospheric pressure.At a substantial gas flow rate,a microwave ...In this study,we explored a one-step direct synthesis of NH3 under mild experimental conditions utilizing pulse-modulated microwave plasma technology at atmospheric pressure.At a substantial gas flow rate,a microwave plasma jet was formed and the microwave-assisted ammonia synthesis can be realized.Impacts of various parameters including the gas flow rate,gas component,microwave absorbed power,pulse modulation frequency,and pulse duty cycle on ammonia synthesis were systematically investigated.To indicate the reaction path of ammonia synthesis,the distributions of both the gas temperature and active species were also studied using optical emission spectra technology.It is found that a considerable amount of ammonia was directly synthesized without involvement of any catalysts,the highest ammonia production rate and energy efficiency(EE),up to 2.93μmol·min^(-1) and 6.64×10^(-2)g·(k W·h)^(-1),respectively,were achieved under low microwave power of 84.42 W.The duty cycle has obvious influences on the synthesis efficiency,compared to a duty cycle of 80%,the ammonia synthesis rate,EE and nitrogen conversion decreased by about 22%at a duty cycle of 100%.This finding underscores the significance of incorporating pulse modulation in the microwave discharge process for ammonia synthesis.Furthermore,it was found that vibrational excitation of microwave plasma has a significant driving effect on ammonia synthesis.展开更多
The phenomenon of shock/shock interaction(SSI)is widely observed in high-speed flow,and the double wedge SSI represents one of the typical problems encountered.The control effect of single-pulse plasma synthetic jet(P...The phenomenon of shock/shock interaction(SSI)is widely observed in high-speed flow,and the double wedge SSI represents one of the typical problems encountered.The control effect of single-pulse plasma synthetic jet(PSJ)on double wedge type-Ⅵand type-ⅤSSI was investigated experimentally and numerically,and the influence of discharge energy was also explored.The findings indicate that the interaction between PSJ and the high-speed freestream results in the formation of a plasma layer and a jet shock,which collectively governs the control of SSI.The control mechanism of single-pulse PSJ on SSI lies in its capacity to attenuate both shock and SSI.For type-ⅥSSI,the original second-wedge oblique shock is eliminated under the control of PSJ,resulting in a new type-ⅥSSI formed by the jet shock and the first-wedge oblique shock.For type-ⅤSSI,the presence of PSJ effectively mitigates the intensity of Mach stem,supersonic jet,and reflected shocks,thereby facilitating its transition into type-ⅥSSI.The numerical results indicate that the peak pressure can be reduced by approximately 32.26%at maximum.Furthermore,the development of PSJ also extends in the Z direction.The pressure decreases in the area affected by both PSJ and jet shock due to the attenuation of the SSI zone.With increasing discharge energy,the control effect of PSJ on SSI is gradually enhanced.展开更多
ENN is planning the next generation experimental device EHL-2 with the goal to verify the thermal reaction rates of p-^(11)B fusion,establish spherical torus/tokamak experimental scaling laws at 10’s keV ion temperat...ENN is planning the next generation experimental device EHL-2 with the goal to verify the thermal reaction rates of p-^(11)B fusion,establish spherical torus/tokamak experimental scaling laws at 10’s keV ion temperature,and provide a design basis for subsequent experiments to test and realize the p-^(11)B fusion burning plasma.Based on 0-dimensional(0-D)system design and 1.5-dimensional transport modelling analyses,the main target parameters of EHL-2 have been basically determined,including the plasma major radius,R0,of 1.05 m,the aspect ratio,A,of 1.85,the maximum central toroidal magnetic field strength,B0,of 3 T,and the plasma toroidal current,Ip,of 3 MA.The main heating system will be the neutral beam injection at a total power of 17 MW.In addition,6 MW of electron cyclotron resonance heating will serve as the main means of local current drive and MHD instabilities control.The physics design of EHL-2 is focused on addressing three main operating scenarios,i.e.,(1)high ion temperature scenario,(2)high-performance steady-state scenario and(3)high triple product scenario.Each scenario will integrate solutions to different important issues,including equilibrium configuration,heating and current drive,confinement and transport,MHD instability,p-^(11)B fusion reaction,plasma-wall interactions,etc.Beyond that,there are several unique and significant challenges to address,including●establish a plasma with extremely high core ion temperature(T_(i,0)>30 keV),and ensure a large ion-to-electron tempera-ture ratio(T_(i,0)/Te,0>2),and a boron concentration of 10%‒15%at the plasma core;●realize the start-up by non-inductive current drive and the rise of MA-level plasma toroidal current.This is because the volt-seconds that the central solenoid of the ST can provide are very limited;●achieve divertor heat and particle fluxes control including complete detachment under high P/R(>20 MW/m)at rela-tively low electron densities.This overview will introduce the advanced progress in the physics design of EHL-2.展开更多
The cylindrical virtual cathode reflex triode is a new type of pulsed hard X-ray load,which has the advantages of simple structure,high radiation conversion efficiency,and simplicity in seriesparallel operation.This p...The cylindrical virtual cathode reflex triode is a new type of pulsed hard X-ray load,which has the advantages of simple structure,high radiation conversion efficiency,and simplicity in seriesparallel operation.This paper presents a method to reduce the impedance of the triode using a multiring cathode.The average electric field on the ring-cathode emission surface is enhanced due to edge effect,and the beam intensity is greatly increased in proportion to the square of the electric field strength.Multi-ring cathode is used to enlarge the emission area.Therefore,the reflex triode can work at lower impedance and generate a stronger beam under the same anode-cathode gap.In addition,the electric field enhancement of the cathode reduces the cathode emission stabilization time and enhances the operation stability of the triode.The effects of parameters such as ring width and ring gap on the triode impedance are simulated and studied.The cathode emission stabilization time and the X-ray conversion efficiency are compared.The design basis of cathode structure parameters and the impedance control method of the cylindrical virtual cathode reflex triode are given according to the simulations.展开更多
In laser wakefield acceleration,injecting an external electron beam at a certain energy is a promising approach for achieving a high-quality electron beam with low energy spread and low emittance.In this paper,the pro...In laser wakefield acceleration,injecting an external electron beam at a certain energy is a promising approach for achieving a high-quality electron beam with low energy spread and low emittance.In this paper,the process of laser wakefield acceleration with an external injection at 10 pC has been studied in simulations.A Bayesian optimization method is used to optimize the key laser and plasma parameters so that the electron beam is accelerated to the expected energy with a small emittance and energy spread growth.The effect of the rising edge of the plasma on the transverse properties of the electron beam is simulated and optimized in order to ensure that the external electron beam is injected into the plasma without significant emittance growth.Finally,a high-quality electron beam with an energy of 1.5 GeV,a normalized transverse emittance of 0.5 mm·mrad and a relative energy spread of 0.5%at 10 pC is obtained.展开更多
基金funded by National Natural Science Foundation of China under Grant [31760045 and 31970220]Natural Science Foundation of Guangxi Province under Grant[2018GXNSFAA281132]。
文摘Fruit colour is essential to seed dispersal,speciation,and biological diversity in global ecosystems.The relationship between fruit-colour variation and species diversification has long been of interest in evolutionary biology,but remains poorly understood at the genus level.Here,we used Callicarpa,a typical representative of pantropical angiosperm,to analyse whether fruit colours are correlated with biogeographic distribution,dispersal events,and diversification rate.We estimated a time-calibrated phylogeny for Callicarpa and reconstructed ancestral fruit colour.Utilizing phylogenetic methods,we estimated the major dispersal events across the phylogenetic tree and the most likely fruit colours related to each dispersal event,and tested whether the dispersal frequencies and distances of the four fruit colours between major biogeographical areas were equal.We then tested whether fruit colours are correlated with latitude,elevation,and diversification rate.Biogeographical reconstructions showed that Callicarpa originated in the East Asia and Southeast Asia during the Eocene(-35.53 Ma) and diverse species diverged mainly in the Miocene and lasted into the Pleistocene.Large-scale dispersal events were significantly associated with violet-fruited lineages.Furthermore,different fruit colours were markedly correlated with different latitudes and elevations(e.g.,violet fruits were correlated with higher latitudes and elevations;red fruits and black fruits with lower latitudes;white fruits with higher elevations).Notably,violet fruits were statistically associated with highest diversification rates,driving fruit colour variation among different regions globally.Our results contribute to further understanding why fruit colour is so variable at the genus level of angiosperms in different areas around the world.
文摘Dahurian larch growing in Daxing’an Mountains can be divided into two types according to the wood colour: one is red, the other is white. Based on the national standard of the "Testing methods for physical &mechanical properties of wood", the parameters of wood colour and physico-mechanical properties of the above two different woods were tested and analyzed.The result showed that the colour rational phenetic parameters, physico-mechanical properties and work abilities of thc two woods were quite different, combincd with the other morphological characteristics, they belong to intraspccific two different types of Dahurian larch. The white wood is superior to the red one as a valuable timber tree. Because the cocfficients of shrinkage, hardness and colour of both are different, they were mixed working in the past, inevitably there have been various defects in working. In order to overcome these defects, we propose that the departments of wood production, salesmen and consumers should use them differently according to their individual character.
文摘The role of bare body parts in sexual signalling in birds has received relatively little attention.I describe how the bare-throated spurfowl males saturate the colours of their throats to attract females.Of the 23 Afrotropical spurfowl species,the bare-throated subgroup includes Yellow-necked Spurfowl(Pternistis leucosceptus),Rednecked Spurfowl(P.afer),Grey-breasted Spurfowl(P.rufopictus) and Swainson’s Spurfowl(P.swainsonii).The rest of the species include fully feathered throated spurfowls.Throat colour intensity of bare throats was scored using an extensive online digital photographic archive encompassing the four species across the year’s seasons.Each throat(n=836) was assigned to one of four colour-intensity categories to explore the relationship between colour intensities,breeding cycles,and environmental variation.Except for Swainson’s Spurfowl male saturation of throat colours correlated with monthly rainfall,which peaks one or two months before egg laying.Swainson’s Spurfowl peaks during egg laying.Yellow-necked Spurfowl has the largest bare throat.Bare-throated spurfowl males perform an elevated courtship display posture above the female to feature their throat colour.No such displays occur in feather-throated spurfowl.Males with low throat colour saturation harbour more ectoparasites on their bare throats than birds with saturated throats.Male Red-necked Spurfowls have significantly larger bare throats than females.The primary function of bare throats probably assists in thermoregulation,particularly in arid regions.The bare throat may have evolved a secondary role in mating.Yellow-necked,Red-necked,and Greybreasted Spurfowls use their saturated throat colours as ornaments to court females during the breeding season.Unobtrusive female throat colours(unsaturated) may discourage male interlopers and predation during egg laying.Saturation appears to be carotenoid-food based.The different colours among the bare-throated species may serve as prezygotic mechanisms that inhibit cross-breeding and explain why females also have coloured throats.
文摘AIM:To compare the Ishihara test errors scores of colour vision deficiency(CVD)subjects when wearing four different types of red-tinted contact lenses(RCL)that differ in their transmittance as determined using a spectrophotometer.METHODS:Six congenital CVD subjects volunteered to participate in this study.Ishihara plates were used to determine the colour vision errors made,whereas Farnsworth-Munsell 100 Hue test was conducted to determine the total error scores(TES)and type of CVD.Four types of RCL(Types A,B,C and D)were inserted in the non-dominant eye and tested in a randomised manner by a masked operator.Errors scores in Ishihara test were determined at baseline without any contact lens and after wearing the four different RCL.The subjects were then divided into two groups based on the mean TES.RESULTS:Repeated measures ANOVA with Greenhouse-Geisser corrections showed that there was a highly significant effect of RCL type on Ishihara error score[F(2.056,10.282)=30.214,P<0.001].Error scores with RCL Type B were significantly lower than errors made when no lens was worn,and with RCL Type C and Type D(all P<0.001).Error scores with RCL Type B were also lower than those made with RCL Type A,however,they were not significantly different.For subjects with TES values less than 180,RCL type B showed the largest improvement in Ishihara error score(50%)compared to the other three RCLs.RCL type A showed the best performance in TES value of more than 180,with an improvement of 80%in Ishihara score.RCL Type A has the lowest transmittance at the confusion wavelength(450-568 nm),followed by RCL Types B,D and C.CONCLUSION:This study shows that RCL can improve Ishihara error scores.RCL with lower transmission at 450-568 nm and 90%transmittance beyond 637 nm are the most effective.Lenses which could block more light between 550-580 nm are more effective for colour defectives with more severe colour defects.
基金supported by a Singapore National Research Foundation(NRF)Investigatorship(NRF-NRFI07-2021-0008)。
文摘Quantitative analysis of colouration is an essential tool for subspecies delimitation but has always posed a challenge in avian taxonomy.In this study on the Chestnut-winged Babbler(Cyanoderma erythropterum)species complex from tropical Southeast Asia,we made use of colour measurements taken with digital cameras and applied two methodologies—(1)the 75%subspecies rule on quantitative colourimetric variables,and(2)the CIEDE2000 colour distance method to generate phylograms,which has probably never been applied in taxonomy before.Given its large number of described subspecies,many of which have been synonymised in modern taxonomies,the species complex serves as an appropriate model to test subspecies validity.Our data indicate that one synonymised subspecies(C.e.apega),from the islands of Bangka and Belitung,requires re-instalment and recognition,whereas one widely recognised subspecies(C.e.fulviventre),from the Banyak Islands,should be synonymised.Our approach also allowed us to redraw geographic subspecies boundaries.Our work indicates that current subspecies taxonomies of many poorly known tropical species may remain error-ridden and highlights the importance and viability of large-scale taxonomic revisions targeting avian subspecies globally while incorporating quantitative colourimetric approaches.
文摘This work presents a grounding protection system of the central solenoid model coil(CSMC)of the Comprehensive Research Facility for Fusion Technology(CRAFT).The scheme of neutral point voltage detections has been adopted in grounding protection system.Compared with the usual current acquisition,the measurement data is accurate,there is no redundant loop,and the economic benefit is high.In this study,the single-end and double-end grounding fault protections of superconducting magnet coil are analyzed,and the fault voltage and current under different fault conditions are calculated.The simulation model of CSMC magnet grounding fault is established,and the simulation results of the model are basically consistent with the theoretical calculation.Finally,a small capacity experiment platform is used to verify the function of the grounding protection system.The experimental results show that by comparing the neutral fault sampling voltage with the theoretical grounding protection threshold,the grounding protection system can effectively detect different types of grounding faults and transmit signals to the control system to protect the coils of superconducting magnets.
基金supported by the Comprehensive Research Facility for Fusion Technology Program of China(No.2018000052-73-01-001228)National Natural Science Foundation of China(No.11975263)Postgraduate Research and Practice Innovation Program of NUAA(No.xcxjh20231501)。
文摘The negative ion based neutral beam injector(NNBI)with a beam energy of 400 keV is one of the subsystems at the Comprehensive Research fAcility for Fusion Technology(CRAFT)in China.The distributed capacitance of the high-voltage components is an important basis for the design of surge suppression devices at CRAFT NNBI.This study conducted calculations of distributed capacitance for the key components,including the high-voltage deck,transmission line and isolation transformer in the power supply system using the finite element method.The relationship between the high-voltage deck(HVD)distributed capacitance and the distance from the wall is discussed.The differences in distributed capacitance and energy storage between noncoaxial and coaxial transmission lines are also debated.Finally,the capacitance between the primary and secondary windings of the-400 kV isolation transformer,as well as between the secondary winding and the oil tank casing,was calculated.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2022YFE03100004,2017YFE0301700 and 2017 YFE0301701)National Natural Science Foundation of China(Nos.12375226,11875255,11635008,11375188 and 11975231)。
文摘The electromagnetic turbulence in reversed field pinch(RFP)plasmas exhibits three-dimensional characteristics.Suppression of this turbulence is crucial for enhancing plasma confinement,necessitating control over the electric field or the current profile.To this end,two sets of electrodes have been designed and installed on the Keda Torus eXperiment(KTX)RFP device to manipulate the edge electric field and the edge parallel current profile.Subsequently,the edge radial electric field and edge parallel current profile control experiments are conducted.In the edge radial electric field control experiments,the edge radial electric field is altered under bias,accompanied with an increase in the electron density and plasma duration.However,under bias,both electrostatic and magnetic fluctuations are enhanced.In the edge parallel current profile control experiments,the results indicate that bias modifies the edge parallel current profile locally,leading to a localized increase in the field reversal depth and electron density.Additionally,a reduction in magnetic fluctuations is observed within the reversed field enhanced region under bias,suggesting that the bias suppresses magnetic perturbations.
基金the financial support of National Natural Science Foundation of China(Nos.52207175 and 52407178)。
文摘When discharge faults occur in dry air switchgear,the air decomposes to produce diverse gases,with NO_(2) reaching the highest levels.Detecting the NO_(2) level can reflect the operation status of the equipment.This paper proposes to combine ZnO cluster with MoS_(2) to improve the gassensitive properties of the monolayer.Based on the Density Functional Theory(DFT),the effect of(ZnO)n size on the behavior of MoS_(2 )is considered.Key parameters such as adsorption energy and band gap of(ZnO)n-MoS_(2)/NO_(2) system were calculated.The ZnO-MoS_(2) heterojunction was successfully synthesized by a hydrothermal method.The gas sensor exhibits a remarkable response and a fast response-recovery time to 100 ppm NO_(2).In addition,it demonstrates excellent selectivity,long-term stability and a low detection limit.This work confirms the potential of the ZnO-MoS_(2) composite structure as a highly effective gas sensor for NO_(2) detection,which provides valuable theoretical and experimental insights for fault detection in dry air switchgear.
基金partly supported by SWIP project(No.SWIP-JYHT-12423).
文摘The EHL-2 spherical torus at ENN is the next-generation experimental platform under conceptual design,aiming at realizing proton-boron(p-^(11)B)thermonuclear fusion,which is an attractive pathway towards neutron-free fusion.To achieve high-performance steady-state plasma,it is extremely necessary to study the turbulence transport characteristics with high boron content in the plasma core.This study investigates the transport properties in the core internal transport barrier(ITB)region of p-^(11)B plasma utilizing the gyrokinetic code GENE in view of the high ion temperature scenario of EHL-2,specifically focusing on the impact of boron fractions and plasmaβon the microinstabilities and corresponding transport features.Numerical findings indicate that the inclusion of boron species effectively suppresses the trapped electron modes(TEMs)as well as promoting a transition from electromagnetic to electrostatic turbulence with increased boron fraction,which is a result of the suppression of microinstabilities by effective charge and mass.Moreover,it has been identified that the external E×B rotational shear has a notable inhibitory influence on transport,which can reduce the transport level by two to three orders of magnitude,especially at medium boron content.The suppressive effect of E×B on turbulence is weakened once the kinetic ballooning mode(KBM)is excited and the transport shows a rapid increase withβtogether with a reduction in zonal flow amplitude,which is consistent with previous findings.Therefore,it is strongly suggested that exploring advanced strategies for mitigating turbulent transport at highβregimes is necessary for the active control of plasma behavior regarding p-^(11)B plasma-based fusion devices such as EHL-2.
基金supported by National Natural Science Foundation of China(Nos.52077026,51977023,52177126 and 12475253)the Fundamental Research Funds for the Central Universities(No.DUT23YG227)the Dalian Life&Health Guiding Project(No.2023ZXYG34)。
文摘In this study,we explored a one-step direct synthesis of NH3 under mild experimental conditions utilizing pulse-modulated microwave plasma technology at atmospheric pressure.At a substantial gas flow rate,a microwave plasma jet was formed and the microwave-assisted ammonia synthesis can be realized.Impacts of various parameters including the gas flow rate,gas component,microwave absorbed power,pulse modulation frequency,and pulse duty cycle on ammonia synthesis were systematically investigated.To indicate the reaction path of ammonia synthesis,the distributions of both the gas temperature and active species were also studied using optical emission spectra technology.It is found that a considerable amount of ammonia was directly synthesized without involvement of any catalysts,the highest ammonia production rate and energy efficiency(EE),up to 2.93μmol·min^(-1) and 6.64×10^(-2)g·(k W·h)^(-1),respectively,were achieved under low microwave power of 84.42 W.The duty cycle has obvious influences on the synthesis efficiency,compared to a duty cycle of 80%,the ammonia synthesis rate,EE and nitrogen conversion decreased by about 22%at a duty cycle of 100%.This finding underscores the significance of incorporating pulse modulation in the microwave discharge process for ammonia synthesis.Furthermore,it was found that vibrational excitation of microwave plasma has a significant driving effect on ammonia synthesis.
基金supported by the Independent Innovation Science Fund of National University of Defense Technology(No.24-ZZCX-BC-05)National Natural Science Foundation of China(Nos.92271110 and 12202488)+2 种基金the Major National Science and Technology Project(No.J2019-Ⅲ0010-0054)the National Postdoctoral Researcher Program of China(No.GZB20230985)the Natural Science Program of National University of Defense Technology(No.ZK22-30)。
文摘The phenomenon of shock/shock interaction(SSI)is widely observed in high-speed flow,and the double wedge SSI represents one of the typical problems encountered.The control effect of single-pulse plasma synthetic jet(PSJ)on double wedge type-Ⅵand type-ⅤSSI was investigated experimentally and numerically,and the influence of discharge energy was also explored.The findings indicate that the interaction between PSJ and the high-speed freestream results in the formation of a plasma layer and a jet shock,which collectively governs the control of SSI.The control mechanism of single-pulse PSJ on SSI lies in its capacity to attenuate both shock and SSI.For type-ⅥSSI,the original second-wedge oblique shock is eliminated under the control of PSJ,resulting in a new type-ⅥSSI formed by the jet shock and the first-wedge oblique shock.For type-ⅤSSI,the presence of PSJ effectively mitigates the intensity of Mach stem,supersonic jet,and reflected shocks,thereby facilitating its transition into type-ⅥSSI.The numerical results indicate that the peak pressure can be reduced by approximately 32.26%at maximum.Furthermore,the development of PSJ also extends in the Z direction.The pressure decreases in the area affected by both PSJ and jet shock due to the attenuation of the SSI zone.With increasing discharge energy,the control effect of PSJ on SSI is gradually enhanced.
文摘ENN is planning the next generation experimental device EHL-2 with the goal to verify the thermal reaction rates of p-^(11)B fusion,establish spherical torus/tokamak experimental scaling laws at 10’s keV ion temperature,and provide a design basis for subsequent experiments to test and realize the p-^(11)B fusion burning plasma.Based on 0-dimensional(0-D)system design and 1.5-dimensional transport modelling analyses,the main target parameters of EHL-2 have been basically determined,including the plasma major radius,R0,of 1.05 m,the aspect ratio,A,of 1.85,the maximum central toroidal magnetic field strength,B0,of 3 T,and the plasma toroidal current,Ip,of 3 MA.The main heating system will be the neutral beam injection at a total power of 17 MW.In addition,6 MW of electron cyclotron resonance heating will serve as the main means of local current drive and MHD instabilities control.The physics design of EHL-2 is focused on addressing three main operating scenarios,i.e.,(1)high ion temperature scenario,(2)high-performance steady-state scenario and(3)high triple product scenario.Each scenario will integrate solutions to different important issues,including equilibrium configuration,heating and current drive,confinement and transport,MHD instability,p-^(11)B fusion reaction,plasma-wall interactions,etc.Beyond that,there are several unique and significant challenges to address,including●establish a plasma with extremely high core ion temperature(T_(i,0)>30 keV),and ensure a large ion-to-electron tempera-ture ratio(T_(i,0)/Te,0>2),and a boron concentration of 10%‒15%at the plasma core;●realize the start-up by non-inductive current drive and the rise of MA-level plasma toroidal current.This is because the volt-seconds that the central solenoid of the ST can provide are very limited;●achieve divertor heat and particle fluxes control including complete detachment under high P/R(>20 MW/m)at rela-tively low electron densities.This overview will introduce the advanced progress in the physics design of EHL-2.
基金supported by National Natural Science Foundation of China(Nos.12027811 and 12275222)。
文摘The cylindrical virtual cathode reflex triode is a new type of pulsed hard X-ray load,which has the advantages of simple structure,high radiation conversion efficiency,and simplicity in seriesparallel operation.This paper presents a method to reduce the impedance of the triode using a multiring cathode.The average electric field on the ring-cathode emission surface is enhanced due to edge effect,and the beam intensity is greatly increased in proportion to the square of the electric field strength.Multi-ring cathode is used to enlarge the emission area.Therefore,the reflex triode can work at lower impedance and generate a stronger beam under the same anode-cathode gap.In addition,the electric field enhancement of the cathode reduces the cathode emission stabilization time and enhances the operation stability of the triode.The effects of parameters such as ring width and ring gap on the triode impedance are simulated and studied.The cathode emission stabilization time and the X-ray conversion efficiency are compared.The design basis of cathode structure parameters and the impedance control method of the cylindrical virtual cathode reflex triode are given according to the simulations.
基金supported by Science and Technology Major Project of Hubei Province in China(No.2021AFB001)。
文摘In laser wakefield acceleration,injecting an external electron beam at a certain energy is a promising approach for achieving a high-quality electron beam with low energy spread and low emittance.In this paper,the process of laser wakefield acceleration with an external injection at 10 pC has been studied in simulations.A Bayesian optimization method is used to optimize the key laser and plasma parameters so that the electron beam is accelerated to the expected energy with a small emittance and energy spread growth.The effect of the rising edge of the plasma on the transverse properties of the electron beam is simulated and optimized in order to ensure that the external electron beam is injected into the plasma without significant emittance growth.Finally,a high-quality electron beam with an energy of 1.5 GeV,a normalized transverse emittance of 0.5 mm·mrad and a relative energy spread of 0.5%at 10 pC is obtained.
