Smoothed cepstral peak prominence(CPPs)is a measurement of the distance from the prominent cepstral peak to the linear regression line directly beneath it.Variations of CPPs data acquisition and analysis lead to the c...Smoothed cepstral peak prominence(CPPs)is a measurement of the distance from the prominent cepstral peak to the linear regression line directly beneath it.Variations of CPPs data acquisition and analysis lead to the complexity of the clinical cut-off values,and there are no agreeable values for a specific voice disorder,such as hypokinetic dysarthria associated with Parkinson’s disease(PD).This study examined the CPPs in people with hypokinetic dysarthria associated with PD compared with healthy participants.Results demonstrated significant differences in speech tasks of sustained vowel and connected speech,with CPPs of connected speech more sensitive to dysphonia and gender difference in PD participants.Males in PD participants presented higher CPPs for sustained vowels and lower CPPs for connected speech than females.It is implied that a consistent clinical application protocol is necessary,and multiple acoustic measures are needed to ensure the accuracy of clinical decisions.展开更多
The assortedness of Chinese food,together with the complexity of their naming elements,has ignited numerous scholars' interests in this field and prompted them to make abundant analyses of Chinese dish names.Most ...The assortedness of Chinese food,together with the complexity of their naming elements,has ignited numerous scholars' interests in this field and prompted them to make abundant analyses of Chinese dish names.Most of them,however,were done in studies of traditional linguistics,rhetoric,translatology and cross-cultural communication.And studies,based on corpus,on the naming elements of Chinese dishes under cognitive linguistic theories almost remain a blank.This paper aims to conduct a quantitative analysis of 4,000 Chinese dish names(500 ones selected freely from each of the eight cuisines),based on the Prominence Principle,in order to identify the specific naming elements of Chinese dishes and forward related statistics and ratios.展开更多
After surveying the spectra of 39 prominences observed by the Multi-channel Infrared Solar Spectrograph at Purple Mountain Observatory and the 25 cm coronagraph at the Norikura Solar Observatory, we found that about 2...After surveying the spectra of 39 prominences observed by the Multi-channel Infrared Solar Spectrograph at Purple Mountain Observatory and the 25 cm coronagraph at the Norikura Solar Observatory, we found that about 28% of them show small spatial scale (6''–8'') and short time scale (tens of seconds to a few minutes), unusual large broadening and large shift velocities in spectral lines including Hα, Hβ, H, Ca II H, Ca II K, Ca II 8542?, He I D3 and He I 10830?. We present in detail two typical events observed respectively on 2002 May 27 and 1981 August 2. The full-width at half maximum of the widest profile of the 2001 prominence is 1.8? for Hα and 2.9 ? for He I 10830?, while that of the 1981 prominence is 5.3 ? for Hβ, 3.6 ? for Ca II K, 4.0 ? for Ca II H and 2.8 ? for He I D3. Such broadenings generally occur at a level of several-thousand kilometres above the chromosphere. Further, most of these prominences manifest a rotation of (0.4–1.35)×10<SUP>-2</SUP> rads s<SUP>?1</SUP> pointing to the Sun and large line-of-sight velocities of 20–200 km s<SUP>?1</SUP>. Some of these events correspond in time to an enhancement or a small peak in the GOES X-ray flux, indicating the existence of high energy process at work. These prominences generally display discernible changes in the Hα morphology around the time of large broadening, but do not show Hα brightening or overall eruption except for a few small surge-like events, hence, they are hardly observed in daily Hα patrols. According to the characteristics of their Hα structures and spectral properties, we infer these events are small-scale eruptions similar to nano-flares, which may contribute to the mass and energy transported into the corona. Large turbulent velocities of 25–120 km s<SUP>?1</SUP> are responsible for the observed broadenings.展开更多
The mean length of the stria vascularis (SV) and the basilar membrane of four normalguinea pigs measured by means of surface preparation was 21.11 mm and 19. 90 mm respectively,and the mean width of their apical turns...The mean length of the stria vascularis (SV) and the basilar membrane of four normalguinea pigs measured by means of surface preparation was 21.11 mm and 19. 90 mm respectively,and the mean width of their apical turns of SV and the turns of the cochlear basis was 0. 44 mmand 0. 86 mm respectively. The ultrastructure of SV, spiral ligament (SL) and spiral prominence(SP) of both ears of eight guinea pigs were observed by scanning electron microscopy(SEM) andtransmission electron microsoopy(TEM). There were a large number of coated vesicles in thesupranuclear region of SV, some opened to the endolymph. A great number of folding cytoplasmicprojections were filled with small vesicles The capillary network was extremely rich indicating thatthe endolymph could be secreted and absorbed by SV. The cellular conjunction in the SV. SL andSP formed an effective barrier. It has not been proved in this study that the melanin offers resistanceto acoustic stimulation.展开更多
A 2D velocity field of the eruptive prominence (EP) of 1991 March 5 is obtained from its spectral data observed at the Yunnan Observatory and the velocity distributions along the entrance slit are derived for differ...A 2D velocity field of the eruptive prominence (EP) of 1991 March 5 is obtained from its spectral data observed at the Yunnan Observatory and the velocity distributions along the entrance slit are derived for different observing frames. Under the assumption that matter in the EP undergoes axial, radial and possible rotational motions, we construct a theoretical velocity distribution of the EP along the entrance slit, to derive, by fitting, the angular velocity of rotation ω and the other three parameters (axial velocity v0, radial velocity vr and the angle between the EP plane and the line of sight Ф). We found: an averaged angular velocity ω of 3.0 × 10^-3 arc s^-1 and the variation of ω with the height above the solar limb. As the EP rises, the matter within it in fact moves along a spiral path around its axis. The spiral motion may be explained by the theory of plasma ‘double pole diffusion' (DPD) caused by a sharp density gradient between the eruptive prominence and the surrounding corona. A theoretical angular velocity ω′ is estimated based on the DPD and basically coincides with ω obtained from the optimal velocity fitting.展开更多
Relations between China and Malaysia have been developing steadily.Recently,See Chee Kong Leonard,Business Minister of Embassy of Malaysia in PRC,accepted an interview with Chinas Foreign Tradey and talked about the 4...Relations between China and Malaysia have been developing steadily.Recently,See Chee Kong Leonard,Business Minister of Embassy of Malaysia in PRC,accepted an interview with Chinas Foreign Tradey and talked about the 45 years of economic and trade cooperation and achievements of the two countries.展开更多
Prominence plumes are evacuated upflows that emerge from bubbles below prominences,whose formation mechanism is still unclear.Here we present a detailed study of plumes in a quiescent prominence using the high-resolut...Prominence plumes are evacuated upflows that emerge from bubbles below prominences,whose formation mechanism is still unclear.Here we present a detailed study of plumes in a quiescent prominence using the high-resolution Hαfiltergrams at the line center as well as line wing at±0.4 A from the New Vacuum Solar Telescope.Enhancements of brightening,blue shifts,and turbulence at the fronts of plumes are found during their formation.Some large plumes split at their heads and finger-shaped structures are formed between them.Blue-shifted flows along the bubble-prominence interface are found before and during the plume formation.Our observations are consistent with the hypothesis that prominence plumes are related to coupled Kelvin-Helmholtz and Rayleigh-Taylor(KH/RT)instabilities.Plume splittings and fingers are evidence of RT instability,and the flows may increase the growth rate of KH/RT instabilities.However,the significant turbulence at plume fronts may suggest that the RT instability is triggered by the plumes penetrating into the prominence.In this scenario,extra mechanisms are necessary to drive the plumes.展开更多
During total solar eclipses, we can observe the outer atmospheric layers of the sun (chromosphere and corona). The solar corona extends to several solar radii depending on the sunspot cycle. Basic coronal structures s...During total solar eclipses, we can observe the outer atmospheric layers of the sun (chromosphere and corona). The solar corona extends to several solar radii depending on the sunspot cycle. Basic coronal structures such as polar streamers, helmet type structures were?observed?during the 2006 total solar eclipse. Our total solar eclipse 2006 observations through?both White light corona and H-Alpha filter allowed us to describe coronal structures and Prominence Activity. We found that the solar corona is extended to 4 times of solar radii, the existence different zones of white light corona were shown, moreover, we compared the defined features of solar corona at different observing locations along the track of total solar eclipse 2006. The solar limb activity was studied during both of partial and total eclipse phases by using H-Alpha and white light observations from Salloum, Egypt. We got same prominence activity during partial and total phases of the solar eclipse and recorded three prominences on solar limb. Finally, our processed image in a good agreement with the published?processed images?was?observed from different locations along the track of total eclipse,?added, similar magnetic field structure shown in our processed image and published one.展开更多
We investigate the evolutions of two prominences (P1, P2) and two bundles of coronal loops (L1, L2), observed with SDO/AIA near the east solar limb on 2012 September 22. It is found that there were large-amplitude...We investigate the evolutions of two prominences (P1, P2) and two bundles of coronal loops (L1, L2), observed with SDO/AIA near the east solar limb on 2012 September 22. It is found that there were large-amplitude oscillations in P1 and L1 but no detectable motions in P2 and L2. These transverse oscillations were triggered by a large-scale coronal wave, originating from a large flare in a remote active region behind the solar limb. By carefully comparing the locations and heights of these oscillating and non-oscillating structures, we conclude that the propagating height of the wave is between 50 Mm and 130 Mm. The wave energy deposited in the oscillating prominence and coronal loops is at least of the order of 10-8 erg. Furthermore, local magnetic field strength and Alfv6n speeds are derived from the oscillating periods and damping time scales, which are extracted from the time series of the oscillations. It is demon- strated that oscillations can be used in not only coronal seismology, but also to reveal the properties of the wave.展开更多
This present paper, in perspective of cognitive prominence, the cognitive motive on the differences between English and Chinese subjects, and then explores the interpretability of the Adaptation Theory in translating ...This present paper, in perspective of cognitive prominence, the cognitive motive on the differences between English and Chinese subjects, and then explores the interpretability of the Adaptation Theory in translating the subjects. It is discovered that the blending of the cognitive prominence and the theory of adaptation is very effective in elaborating the subtle differences of English and Chinese subjects in translation, and reasonable in expounding the infeasibility of some plausible versions.展开更多
During vertebrate embryonic development,neural crest-derived ectomesenchyme within the maxillary prominences undergoes precisely coordinated proliferation and differentiation to give rise to diverse craniofacial struc...During vertebrate embryonic development,neural crest-derived ectomesenchyme within the maxillary prominences undergoes precisely coordinated proliferation and differentiation to give rise to diverse craniofacial structures,such as tooth and palate.However,the transcriptional regulatory networks underpinning such an intricate process have not been fully elucidated.Here,we perform single-cell RNA-Seq to comprehensively characterize the transcriptional dynamics during mouse maxillary development from embryonic day(E)10.5eE14.5.Our single-cell transcriptome atlas of~28,000 cells uncovers mesenchymal cell populations representing distinct differentiating states and reveals their developmental trajectory,suggesting that the segregation of dental from the palatal mesenchyme occurs at E11.5.Moreover,we identify a series of key transcription factors(TFs)associated with mesenchymal fate transitions and deduce the gene regulatory networks directed by these TFs.Collectively,our study provides important resources and insights for achieving a systems-level understanding of craniofacial morphogenesis and abnormality.展开更多
The solar flare is one of the most violent explosions,and can disturb the near-Earth space weather.Except for commonly single-peaked solar flares in soft X-ray,some special flares show intriguing a two-peak feature th...The solar flare is one of the most violent explosions,and can disturb the near-Earth space weather.Except for commonly single-peaked solar flares in soft X-ray,some special flares show intriguing a two-peak feature that is deserved much more attentions.Here,we reported a confined two-peaked solar flare and analyzed the associated eruptions using high-quality observations from Educational Adaptive-optics Solar Telescope and Solar Dynamics Observatory.Before the flare,a magnetic flux rope(MFR)formed through partially tether-cutting reconnection between two sheared arches.The flare occurred after the MFR eruption that was confined by the overlying strong field.Interestingly,a small underlying filament immediately erupted,which was possibly destabilized by the flare ribbon.The successive eruptions were confirmed by the analysis of the emission measure and the reconnection fluxes.Therefore,we suggest that the two peaks of the confined solar flare are corresponding to two episodes of magnetic reconnection during the successive eruptions of the MFR and the underlying filament.展开更多
Small-scale, cyclic, transverse motions of plasma threads are usually seen in solar prominences, which are often interpreted as magnetohydrodynamic(MHD) waves. Here, we observed small-scale decayless transverse oscill...Small-scale, cyclic, transverse motions of plasma threads are usually seen in solar prominences, which are often interpreted as magnetohydrodynamic(MHD) waves. Here, we observed small-scale decayless transverse oscillations in a quiescent prominence, and they appear to be omnipresent. The oscillatory periods of the emission intensity and a proxy for the line-of-sight Doppler shift are about half period of the displacement oscillations. This feature agrees well with the fast kink-mode waves in a flux tube. All the moving threads oscillate transversally spatially in phase and exhibit no significant damping throughout the visible segments, indicating that the fast kink MHD waves are persistently powered and ongoing dissipating energy is transferred to the ambient plasma in the quiet corona. However, our calculations suggest that the energy taken by the fast kink MHD waves alone can not support the coronal heating on the quiet Sun.展开更多
Mg-Gd-Y-Zr alloy,as a typical magnesium rare-earth(Mg-RE)alloy,is gaining popularity in the advanced equipment manufacturing fields owing to its noticeable age-hardening properties and high specific strength.However,i...Mg-Gd-Y-Zr alloy,as a typical magnesium rare-earth(Mg-RE)alloy,is gaining popularity in the advanced equipment manufacturing fields owing to its noticeable age-hardening properties and high specific strength.However,it is extremely challenging to prepare wrought components with large dimensions and complex shapes because of the poor room-temperature processability of Mg-Gd-Y-Zr alloy.Herein,we report a wire-arc directed energy deposited(DED)Mg-10.45Gd-2.27Y-0.52Zr(wt.%,GW102K)alloy with high RE content presenting a prominent combination of strength and ductility,realized by tailored nanoprecipitates through an optimized heat treatment procedure.Specifically,the solution-treated sample exhibits excellent ductility with an elongation(EL)of(14.6±0.1)%,while the aging-treated sample at 200°C for 58 h achieves an ultra-high ultimate tensile strength(UTS)of(371±1.5)MPa.Besides,the aging-treated sample at 250°C for 16 h attains a good strength-ductility synergy with a UTS of(316±2.1)MPa and a EL of(8.5±0.1)%.Particularly,the evolution mechanisms of precipitation response induced by various aging parameters and deformation behavior caused by nanoprecipitates type were also systematically revealed.The excellent ductility resulted from coordinating localized strains facilitated by active slip activity.And the ultra-high strength should be ascribed to the dense nano-β'hampering dislocation motion.Additionally,the shearable nano-β1 contributed to the good strength-ductility synergy.This work thus offers insightful understanding into the nanoprecipitates manipulation and performance tailoring for the wire-arc DED preparation of large-sized Mg-Gd-Y-Zr components with complex geometries.展开更多
Determining whether sevoflurane sedation in children leads to“pseudo”prominent leptomeningeal contrast enhancement(pLMCE)on 3 Tesla magnetic resonance imaging will help reduce overdiagnosis by radiologists and clari...Determining whether sevoflurane sedation in children leads to“pseudo”prominent leptomeningeal contrast enhancement(pLMCE)on 3 Tesla magnetic resonance imaging will help reduce overdiagnosis by radiologists and clarify the pathophysiological changes of pLMCE.展开更多
Many authors have studied the regularity and properties of evolution and eruption of the helical prominence observationally or theoretically. We proposed that Lundquist field may be a good configuration to describe th...Many authors have studied the regularity and properties of evolution and eruption of the helical prominence observationally or theoretically. We proposed that Lundquist field may be a good configuration to describe the inner magnetic distribution of the helical promincence by analyzing this kind of quiescent and eruptive prominences. In this note,we discuss the stable criterion of Lundquist field according to energy principle and compare theory with observational data of 28 helical prominences. This work not only has confirmed the close relation between the Lundquist field and the helical prominence, but al-展开更多
Ⅰ. INTRODUCTION In the last decade with the increase of time resolution in observational equipments, solar radio fast time structures were discovered at meter, decimeter, centimeter and millimeter wavebands. This has...Ⅰ. INTRODUCTION In the last decade with the increase of time resolution in observational equipments, solar radio fast time structures were discovered at meter, decimeter, centimeter and millimeter wavebands. This has let to a surge of discussions about the mechanisms producing fast fine structures. However, the observed phenomenon of switch-type fast active groups coexisting with a loop prominence is for the first time in this field, this note mainly intends to describe the morphology and characteristics of the interesting event we observed on August 17, 1989 and to present the parameters about the rate of spikes and duration of indi-展开更多
The study of the prominence velocity field is important for understanding the formation and evolution. People have found the macroscopic flow of cool material moving along the prominence. Engvold reported the downward...The study of the prominence velocity field is important for understanding the formation and evolution. People have found the macroscopic flow of cool material moving along the prominence. Engvold reported the downward motion of展开更多
As is well-known to all,English has been used as an international common language and has also become the world's most widespread language. For quite some time,English teaching has been aiming at the training of g...As is well-known to all,English has been used as an international common language and has also become the world's most widespread language. For quite some time,English teaching has been aiming at the training of grammar and lexical words,and stress teaching has been largely ignored.However,as English communicative function is playing a more and more vital role in recent years,great impor-tance has been attached to stress in English teaching and learning. Based on the theory of English stress pattern,this study investigates the stress features of middle school students from the per-spectives of pitch and duration prominence on content words and function words. In addition,this study makes a comparison between Chinese and English stress patterns,and offers some pedagogical sugges-tions.English stress requires more attention in English teaching and learning. It is also recommended that the teachers guide the students to use stress in various contexts and offer them more trainings.展开更多
Lyα(Lyα,1216 A)is the strongest emission line in the solar ultraviolet spectrum.In the present work,we obtained a Lyαenhancement catalog covering flares larger than B1 class from the GOES/EUVS data during 2010-2016...Lyα(Lyα,1216 A)is the strongest emission line in the solar ultraviolet spectrum.In the present work,we obtained a Lyαenhancement catalog covering flares larger than B1 class from the GOES/EUVS data during 2010-2016.We focused on the 242 B-class events which are less investigated,however,show non-negligible Lyαemission enhancement.We found that on average the Lyαpeak of B-class flares is 0.85%stronger than the background.For the flare energetics,it is found that the weaker the soft X-ray(SXR)flare,the larger the ratio of the radiated energy in Lyαto SXR.Using the RHESSI data and multi-wavelength observations taken by SDO-AIA,we diagnose the thermal and non-thermal properties of several flares.Three case studies show that the coincidence of the Lyαpeak with the SXR time-derivative peak is not a sufficient condition of the nonthermal property of a Lyαmicroflare.The Lyαenhancement in the microflares may be caused by the nonthermal electron beams or/and thermal conduction.However for typeⅢevents,we found that the delay of the Lyαpeak with respect to the SXR peak can be attributed to either the Lyαemission from a filament erupted or the cooling of the thermal plasma in flare loops.Furthermore,interestingly the Lyαemission from filaments can not only occur in the decay phase of the flare,but also in the preflare phase.In this case,the Lyαemission was originated from an erupted filament which probably initiated the flare.展开更多
文摘Smoothed cepstral peak prominence(CPPs)is a measurement of the distance from the prominent cepstral peak to the linear regression line directly beneath it.Variations of CPPs data acquisition and analysis lead to the complexity of the clinical cut-off values,and there are no agreeable values for a specific voice disorder,such as hypokinetic dysarthria associated with Parkinson’s disease(PD).This study examined the CPPs in people with hypokinetic dysarthria associated with PD compared with healthy participants.Results demonstrated significant differences in speech tasks of sustained vowel and connected speech,with CPPs of connected speech more sensitive to dysphonia and gender difference in PD participants.Males in PD participants presented higher CPPs for sustained vowels and lower CPPs for connected speech than females.It is implied that a consistent clinical application protocol is necessary,and multiple acoustic measures are needed to ensure the accuracy of clinical decisions.
文摘The assortedness of Chinese food,together with the complexity of their naming elements,has ignited numerous scholars' interests in this field and prompted them to make abundant analyses of Chinese dish names.Most of them,however,were done in studies of traditional linguistics,rhetoric,translatology and cross-cultural communication.And studies,based on corpus,on the naming elements of Chinese dishes under cognitive linguistic theories almost remain a blank.This paper aims to conduct a quantitative analysis of 4,000 Chinese dish names(500 ones selected freely from each of the eight cuisines),based on the Prominence Principle,in order to identify the specific naming elements of Chinese dishes and forward related statistics and ratios.
基金Support by the National Natural Science Foundation of China.
文摘After surveying the spectra of 39 prominences observed by the Multi-channel Infrared Solar Spectrograph at Purple Mountain Observatory and the 25 cm coronagraph at the Norikura Solar Observatory, we found that about 28% of them show small spatial scale (6''–8'') and short time scale (tens of seconds to a few minutes), unusual large broadening and large shift velocities in spectral lines including Hα, Hβ, H, Ca II H, Ca II K, Ca II 8542?, He I D3 and He I 10830?. We present in detail two typical events observed respectively on 2002 May 27 and 1981 August 2. The full-width at half maximum of the widest profile of the 2001 prominence is 1.8? for Hα and 2.9 ? for He I 10830?, while that of the 1981 prominence is 5.3 ? for Hβ, 3.6 ? for Ca II K, 4.0 ? for Ca II H and 2.8 ? for He I D3. Such broadenings generally occur at a level of several-thousand kilometres above the chromosphere. Further, most of these prominences manifest a rotation of (0.4–1.35)×10<SUP>-2</SUP> rads s<SUP>?1</SUP> pointing to the Sun and large line-of-sight velocities of 20–200 km s<SUP>?1</SUP>. Some of these events correspond in time to an enhancement or a small peak in the GOES X-ray flux, indicating the existence of high energy process at work. These prominences generally display discernible changes in the Hα morphology around the time of large broadening, but do not show Hα brightening or overall eruption except for a few small surge-like events, hence, they are hardly observed in daily Hα patrols. According to the characteristics of their Hα structures and spectral properties, we infer these events are small-scale eruptions similar to nano-flares, which may contribute to the mass and energy transported into the corona. Large turbulent velocities of 25–120 km s<SUP>?1</SUP> are responsible for the observed broadenings.
文摘The mean length of the stria vascularis (SV) and the basilar membrane of four normalguinea pigs measured by means of surface preparation was 21.11 mm and 19. 90 mm respectively,and the mean width of their apical turns of SV and the turns of the cochlear basis was 0. 44 mmand 0. 86 mm respectively. The ultrastructure of SV, spiral ligament (SL) and spiral prominence(SP) of both ears of eight guinea pigs were observed by scanning electron microscopy(SEM) andtransmission electron microsoopy(TEM). There were a large number of coated vesicles in thesupranuclear region of SV, some opened to the endolymph. A great number of folding cytoplasmicprojections were filled with small vesicles The capillary network was extremely rich indicating thatthe endolymph could be secreted and absorbed by SV. The cellular conjunction in the SV. SL andSP formed an effective barrier. It has not been proved in this study that the melanin offers resistanceto acoustic stimulation.
文摘A 2D velocity field of the eruptive prominence (EP) of 1991 March 5 is obtained from its spectral data observed at the Yunnan Observatory and the velocity distributions along the entrance slit are derived for different observing frames. Under the assumption that matter in the EP undergoes axial, radial and possible rotational motions, we construct a theoretical velocity distribution of the EP along the entrance slit, to derive, by fitting, the angular velocity of rotation ω and the other three parameters (axial velocity v0, radial velocity vr and the angle between the EP plane and the line of sight Ф). We found: an averaged angular velocity ω of 3.0 × 10^-3 arc s^-1 and the variation of ω with the height above the solar limb. As the EP rises, the matter within it in fact moves along a spiral path around its axis. The spiral motion may be explained by the theory of plasma ‘double pole diffusion' (DPD) caused by a sharp density gradient between the eruptive prominence and the surrounding corona. A theoretical angular velocity ω′ is estimated based on the DPD and basically coincides with ω obtained from the optimal velocity fitting.
文摘Relations between China and Malaysia have been developing steadily.Recently,See Chee Kong Leonard,Business Minister of Embassy of Malaysia in PRC,accepted an interview with Chinas Foreign Tradey and talked about the 45 years of economic and trade cooperation and achievements of the two countries.
基金supported by the National Natural Science Foundation of China(NSFC,Grant Nos.11427803,U1731241,U1631242 and 11820101002)by CAS Strategic Pioneer Program on Space Science(Grant Nos.XDA15052200,XDA15320103,XDA15320300 and XDA15320301)+2 种基金the Jiangsu Double Innovation PlanNSFC(Grant No.11873091)Yunnan Province Basic Research Plan(No.2019FA001)。
文摘Prominence plumes are evacuated upflows that emerge from bubbles below prominences,whose formation mechanism is still unclear.Here we present a detailed study of plumes in a quiescent prominence using the high-resolution Hαfiltergrams at the line center as well as line wing at±0.4 A from the New Vacuum Solar Telescope.Enhancements of brightening,blue shifts,and turbulence at the fronts of plumes are found during their formation.Some large plumes split at their heads and finger-shaped structures are formed between them.Blue-shifted flows along the bubble-prominence interface are found before and during the plume formation.Our observations are consistent with the hypothesis that prominence plumes are related to coupled Kelvin-Helmholtz and Rayleigh-Taylor(KH/RT)instabilities.Plume splittings and fingers are evidence of RT instability,and the flows may increase the growth rate of KH/RT instabilities.However,the significant turbulence at plume fronts may suggest that the RT instability is triggered by the plumes penetrating into the prominence.In this scenario,extra mechanisms are necessary to drive the plumes.
文摘During total solar eclipses, we can observe the outer atmospheric layers of the sun (chromosphere and corona). The solar corona extends to several solar radii depending on the sunspot cycle. Basic coronal structures such as polar streamers, helmet type structures were?observed?during the 2006 total solar eclipse. Our total solar eclipse 2006 observations through?both White light corona and H-Alpha filter allowed us to describe coronal structures and Prominence Activity. We found that the solar corona is extended to 4 times of solar radii, the existence different zones of white light corona were shown, moreover, we compared the defined features of solar corona at different observing locations along the track of total solar eclipse 2006. The solar limb activity was studied during both of partial and total eclipse phases by using H-Alpha and white light observations from Salloum, Egypt. We got same prominence activity during partial and total phases of the solar eclipse and recorded three prominences on solar limb. Finally, our processed image in a good agreement with the published?processed images?was?observed from different locations along the track of total eclipse,?added, similar magnetic field structure shown in our processed image and published one.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41131065, 41574165, 41421063 and 41304134)MOEC (20113402110001)+2 种基金CAS Key Research Program (KZZD-EW-01-4)the fundamental research funds for the central universities (WK2080000077)the foundation for Young Talents in College of Anhui Province (2013SQRL044ZD)
文摘We investigate the evolutions of two prominences (P1, P2) and two bundles of coronal loops (L1, L2), observed with SDO/AIA near the east solar limb on 2012 September 22. It is found that there were large-amplitude oscillations in P1 and L1 but no detectable motions in P2 and L2. These transverse oscillations were triggered by a large-scale coronal wave, originating from a large flare in a remote active region behind the solar limb. By carefully comparing the locations and heights of these oscillating and non-oscillating structures, we conclude that the propagating height of the wave is between 50 Mm and 130 Mm. The wave energy deposited in the oscillating prominence and coronal loops is at least of the order of 10-8 erg. Furthermore, local magnetic field strength and Alfv6n speeds are derived from the oscillating periods and damping time scales, which are extracted from the time series of the oscillations. It is demon- strated that oscillations can be used in not only coronal seismology, but also to reveal the properties of the wave.
文摘This present paper, in perspective of cognitive prominence, the cognitive motive on the differences between English and Chinese subjects, and then explores the interpretability of the Adaptation Theory in translating the subjects. It is discovered that the blending of the cognitive prominence and the theory of adaptation is very effective in elaborating the subtle differences of English and Chinese subjects in translation, and reasonable in expounding the infeasibility of some plausible versions.
基金supported by the National Natural Science Foundation of China(82071096 to X.W,31970585,32170544,and 31801056 to Q.B.)the National Key Research and Development Program of China(2017YFC1001800 to X.W.,2018YFC1004703 to Q.B),the Fundamental research program funding of Ninth People’s Hospital affiliated to Shanghai Jiao Tong University School of Medicine(JYZZ179 to J.S.)+1 种基金the Innovative research team of high-level local universities in Shanghai(SHSMU-ZLCX20211700)the SHIPM-pi fund No.JY201803 from Shanghai Institute of Precision Medicine,Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine.
文摘During vertebrate embryonic development,neural crest-derived ectomesenchyme within the maxillary prominences undergoes precisely coordinated proliferation and differentiation to give rise to diverse craniofacial structures,such as tooth and palate.However,the transcriptional regulatory networks underpinning such an intricate process have not been fully elucidated.Here,we perform single-cell RNA-Seq to comprehensively characterize the transcriptional dynamics during mouse maxillary development from embryonic day(E)10.5eE14.5.Our single-cell transcriptome atlas of~28,000 cells uncovers mesenchymal cell populations representing distinct differentiating states and reveals their developmental trajectory,suggesting that the segregation of dental from the palatal mesenchyme occurs at E11.5.Moreover,we identify a series of key transcription factors(TFs)associated with mesenchymal fate transitions and deduce the gene regulatory networks directed by these TFs.Collectively,our study provides important resources and insights for achieving a systems-level understanding of craniofacial morphogenesis and abnormality.
基金supported by grants of the National Natural Foundation of China(NSFC12073016)the open topic of the Yunnan Key Laboratory of Solar Physics and Space Science(YNSPCC202217)。
文摘The solar flare is one of the most violent explosions,and can disturb the near-Earth space weather.Except for commonly single-peaked solar flares in soft X-ray,some special flares show intriguing a two-peak feature that is deserved much more attentions.Here,we reported a confined two-peaked solar flare and analyzed the associated eruptions using high-quality observations from Educational Adaptive-optics Solar Telescope and Solar Dynamics Observatory.Before the flare,a magnetic flux rope(MFR)formed through partially tether-cutting reconnection between two sheared arches.The flare occurred after the MFR eruption that was confined by the overlying strong field.Interestingly,a small underlying filament immediately erupted,which was possibly destabilized by the flare ribbon.The successive eruptions were confirmed by the analysis of the emission measure and the reconnection fluxes.Therefore,we suggest that the two peaks of the confined solar flare are corresponding to two episodes of magnetic reconnection during the successive eruptions of the MFR and the underlying filament.
基金supported by the National Natural Science Foundation of China(Grant Nos.11973092,12173012,12111530078,12073081,U1631242,11820101002,11790302,and U1731241)the CAS Strategic Priority Research Program on Space Science(Grant Nos.XDA15052200,XDA15320103,and XDA15320301)+3 种基金supported by the CAS Key Laboratory of Solar Activity(Grant No.KLSA202003)the Surface Project of Jiangsu Province(Grant No.BK20211402)supported by the Shenzhen Technology Project(Grant No.GXWD20201230155427003-20200804151658001)The Laboratory No.is 2010DP173032。
文摘Small-scale, cyclic, transverse motions of plasma threads are usually seen in solar prominences, which are often interpreted as magnetohydrodynamic(MHD) waves. Here, we observed small-scale decayless transverse oscillations in a quiescent prominence, and they appear to be omnipresent. The oscillatory periods of the emission intensity and a proxy for the line-of-sight Doppler shift are about half period of the displacement oscillations. This feature agrees well with the fast kink-mode waves in a flux tube. All the moving threads oscillate transversally spatially in phase and exhibit no significant damping throughout the visible segments, indicating that the fast kink MHD waves are persistently powered and ongoing dissipating energy is transferred to the ambient plasma in the quiet corona. However, our calculations suggest that the energy taken by the fast kink MHD waves alone can not support the coronal heating on the quiet Sun.
基金National Natural Science Foundation of China (52275374, 52205414)Xi’an Jiaotong University Basic Research Funds for Freedom of Exploration and Innovation-Student Programs (xzy022023066)+3 种基金Key Research and Development Projects of Shaanxi Province (2023-YBGY-361)Young Elite Scientists Sponsorship Program by CAST (2021QNRC001)State Key Laboratory for Mechanical Behavior of Materials (20212311)Xiaomi Foundation through Xiaomi Young Scholar Program
文摘Mg-Gd-Y-Zr alloy,as a typical magnesium rare-earth(Mg-RE)alloy,is gaining popularity in the advanced equipment manufacturing fields owing to its noticeable age-hardening properties and high specific strength.However,it is extremely challenging to prepare wrought components with large dimensions and complex shapes because of the poor room-temperature processability of Mg-Gd-Y-Zr alloy.Herein,we report a wire-arc directed energy deposited(DED)Mg-10.45Gd-2.27Y-0.52Zr(wt.%,GW102K)alloy with high RE content presenting a prominent combination of strength and ductility,realized by tailored nanoprecipitates through an optimized heat treatment procedure.Specifically,the solution-treated sample exhibits excellent ductility with an elongation(EL)of(14.6±0.1)%,while the aging-treated sample at 200°C for 58 h achieves an ultra-high ultimate tensile strength(UTS)of(371±1.5)MPa.Besides,the aging-treated sample at 250°C for 16 h attains a good strength-ductility synergy with a UTS of(316±2.1)MPa and a EL of(8.5±0.1)%.Particularly,the evolution mechanisms of precipitation response induced by various aging parameters and deformation behavior caused by nanoprecipitates type were also systematically revealed.The excellent ductility resulted from coordinating localized strains facilitated by active slip activity.And the ultra-high strength should be ascribed to the dense nano-β'hampering dislocation motion.Additionally,the shearable nano-β1 contributed to the good strength-ductility synergy.This work thus offers insightful understanding into the nanoprecipitates manipulation and performance tailoring for the wire-arc DED preparation of large-sized Mg-Gd-Y-Zr components with complex geometries.
基金Supported by the Chongging Medical Scientific Research Project(Joint Project of Chongqing Health Commission and Science and Technology Bureau),No.2022QNXM013 and No.2023MSXM016.
文摘Determining whether sevoflurane sedation in children leads to“pseudo”prominent leptomeningeal contrast enhancement(pLMCE)on 3 Tesla magnetic resonance imaging will help reduce overdiagnosis by radiologists and clarify the pathophysiological changes of pLMCE.
基金Project supported by the National Natural Science Foundation of China
文摘Many authors have studied the regularity and properties of evolution and eruption of the helical prominence observationally or theoretically. We proposed that Lundquist field may be a good configuration to describe the inner magnetic distribution of the helical promincence by analyzing this kind of quiescent and eruptive prominences. In this note,we discuss the stable criterion of Lundquist field according to energy principle and compare theory with observational data of 28 helical prominences. This work not only has confirmed the close relation between the Lundquist field and the helical prominence, but al-
文摘Ⅰ. INTRODUCTION In the last decade with the increase of time resolution in observational equipments, solar radio fast time structures were discovered at meter, decimeter, centimeter and millimeter wavebands. This has let to a surge of discussions about the mechanisms producing fast fine structures. However, the observed phenomenon of switch-type fast active groups coexisting with a loop prominence is for the first time in this field, this note mainly intends to describe the morphology and characteristics of the interesting event we observed on August 17, 1989 and to present the parameters about the rate of spikes and duration of indi-
基金Project supported by the National Natural Science Foundation of China
文摘The study of the prominence velocity field is important for understanding the formation and evolution. People have found the macroscopic flow of cool material moving along the prominence. Engvold reported the downward motion of
文摘As is well-known to all,English has been used as an international common language and has also become the world's most widespread language. For quite some time,English teaching has been aiming at the training of grammar and lexical words,and stress teaching has been largely ignored.However,as English communicative function is playing a more and more vital role in recent years,great impor-tance has been attached to stress in English teaching and learning. Based on the theory of English stress pattern,this study investigates the stress features of middle school students from the per-spectives of pitch and duration prominence on content words and function words. In addition,this study makes a comparison between Chinese and English stress patterns,and offers some pedagogical sugges-tions.English stress requires more attention in English teaching and learning. It is also recommended that the teachers guide the students to use stress in various contexts and offer them more trainings.
基金supported by the National Key R&D Program of China under grants 2022YFF0503003(2022YFF0503000)and 2018YFA0404200the National Natural Science Foundation of China(NSFC,Grant Nos.11921003,11973012,and 11820101002)+1 种基金CAS Strategic Pioneer Program on Space Science(Grant Nos.XDA15018300,XDA15052200,XDA15320103,and XDA15320301)the mobility program(M-0068)of the Sino-German Science Center。
文摘Lyα(Lyα,1216 A)is the strongest emission line in the solar ultraviolet spectrum.In the present work,we obtained a Lyαenhancement catalog covering flares larger than B1 class from the GOES/EUVS data during 2010-2016.We focused on the 242 B-class events which are less investigated,however,show non-negligible Lyαemission enhancement.We found that on average the Lyαpeak of B-class flares is 0.85%stronger than the background.For the flare energetics,it is found that the weaker the soft X-ray(SXR)flare,the larger the ratio of the radiated energy in Lyαto SXR.Using the RHESSI data and multi-wavelength observations taken by SDO-AIA,we diagnose the thermal and non-thermal properties of several flares.Three case studies show that the coincidence of the Lyαpeak with the SXR time-derivative peak is not a sufficient condition of the nonthermal property of a Lyαmicroflare.The Lyαenhancement in the microflares may be caused by the nonthermal electron beams or/and thermal conduction.However for typeⅢevents,we found that the delay of the Lyαpeak with respect to the SXR peak can be attributed to either the Lyαemission from a filament erupted or the cooling of the thermal plasma in flare loops.Furthermore,interestingly the Lyαemission from filaments can not only occur in the decay phase of the flare,but also in the preflare phase.In this case,the Lyαemission was originated from an erupted filament which probably initiated the flare.