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Atomistic evaluation of tension–compression asymmetry in nanoscale body-centered-cubic AlCrFeCoNi high-entropy alloy
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作者 邢润龙 刘雪鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期613-622,共10页
The tension and compression of face-centered-cubic high-entropy alloy(HEA) nanowires are significantly asymmetric, but the tension–compression asymmetry in nanoscale body-centered-cubic(BCC) HEAs is still unclear. In... The tension and compression of face-centered-cubic high-entropy alloy(HEA) nanowires are significantly asymmetric, but the tension–compression asymmetry in nanoscale body-centered-cubic(BCC) HEAs is still unclear. In this study,the tension–compression asymmetry of the BCC Al Cr Fe Co Ni HEA nanowire is investigated using molecular dynamics simulations. The results show a significant asymmetry in both the yield and flow stresses, with BCC HEA nanowire stronger under compression than under tension. The strength asymmetry originates from the completely different deformation mechanisms in tension and compression. In compression, atomic amorphization dominates plastic deformation and contributes to the strengthening, while in tension, deformation twinning prevails and weakens the HEA nanowire.The tension–compression asymmetry exhibits a clear trend of increasing with the increasing nanowire cross-sectional edge length and decreasing temperature. In particular, the compressive strengths along the [001] and [111] crystallographic orientations are stronger than the tensile counterparts, while the [110] crystallographic orientation shows the exactly opposite trend. The dependences of tension–compression asymmetry on the cross-sectional edge length, crystallographic orientation,and temperature are explained in terms of the deformation behavior of HEA nanowire as well as its variations caused by the change in these influential factors. These findings may deepen our understanding of the tension–compression asymmetry of the BCC HEA nanowires. 展开更多
关键词 high-entropy alloys body-centered-cubic NANOWIRE tension–compression asymmetry atomistic simulations
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Exceptional reversed yield strength asymmetry in a rare-earth free Mg alloy containing quasicrystal precipitates
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作者 Qiang Yang Shuhui Lv +2 位作者 Zixiang Yan Zefeng Xie Xin Qiu 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期687-699,共13页
This work reports an exceptional reversed yield strength asymmetry at room temperature for a rare-earth free magnesium alloy containing a mass of fine dispersed quasicrystal(I-phase)precipitates.Although exhibiting tr... This work reports an exceptional reversed yield strength asymmetry at room temperature for a rare-earth free magnesium alloy containing a mass of fine dispersed quasicrystal(I-phase)precipitates.Although exhibiting traditional basal texture,it owns an exceptional CYS/TYS as high as~1.17.Electron back-scattered diffraction(EBSD)and transmission electron microscopy(TEM)examinations indicate pyramidal and prismatic dislocations plus tensile twinning being activated after immediate yielding in compression while basal and non-basal dislocations in tension.I-phase particles transferred the concentrated stress by self-twinning to provide the driving force for tensile twin initiating in neighboring grains,thereby significantly increasing the critical resolved shear stress of tensile twinning to possibly the level of pyramidal slip,finally leading to the dominance of pyramidal slip plus tensile twinning in texture grains.This results in a higher contribution on yield strength by~55 MPa in compression than in tension,which reasonably agrees with the experimental yield strength difference(~38 MPa).It can be concluded that I-phase particles influence deformation modes in tension and in compression,finally result in reversed yield strength asymmetry. 展开更多
关键词 Magnesium alloy Reversed yield strength asymmetry Transmission electron microscopy(TEM) TWINNING Dislocations
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Spatiotemporal variation and freeze-thaw asymmetry of Arctic sea ice in multiple dimensions during 1979 to 2020
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作者 Yu Guo Xiaoli Wang +1 位作者 He Xu Xiyong Hou 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第3期102-114,共13页
Arctic sea ice is broadly regarded as an indicator and amplifier of global climate change.The rapid changes in Arctic sea ice have been widely concerned.However,the spatiotemporal changes in the horizontal and vertica... Arctic sea ice is broadly regarded as an indicator and amplifier of global climate change.The rapid changes in Arctic sea ice have been widely concerned.However,the spatiotemporal changes in the horizontal and vertical dimensions of Arctic sea ice and its asymmetry during the melt and freeze seasons are rarely quantified simultaneously based on multiple sources of the same long time series.In this study,the spatiotemporal variation and freeze-thaw asymmetry of Arctic sea ice were investigated from both the horizontal and vertical dimensions during 1979–2020 based on remote sensing and assimilation data.The results indicated that Arctic sea ice was declining at a remarkably high rate of–5.4×10^(4) km^(2)/a in sea ice area(SIA)and–2.2 cm/a in sea ice thickness(SIT)during 1979 to 2020,and the reduction of SIA and SIT was the largest in summer and the smallest in winter.Spatially,compared with other sub-regions,SIA showed a sharper declining trend in the Barents Sea,Kara Sea,and East Siberian Sea,while SIT presented a larger downward trend in the northern Canadian Archipelago,northern Greenland,and the East Siberian Sea.Regarding to the seasonal trend of sea ice on sub-region scale,the reduction rate of SIA exhibited an apparent spatial heterogeneity among seasons,especially in summer and winter,i.e.,the sub-regions linked to the open ocean exhibited a higher decline rate in winter;however,the other sub-regions blocked by the coastlines presented a greater decline rate in summer.For SIT,the sub-regions such as the Beaufort Sea,East Siberian Sea,Chukchi Sea,Central Arctic,and Canadian Archipelago always showed a higher downward rate in all seasons.Furthermore,a striking freeze-thaw asymmetry of Arctic sea ice was also detected.Comparing sea ice changes in different dimensions,sea ice over most regions in the Arctic showed an early retreat and rapid advance in the horizontal dimension but late melting and gradual freezing in the vertical dimension.The amount of sea ice melting and freezing was disequilibrium in the Arctic during the considered period,and the rate of sea ice melting was 0.3×10^(4) km^(2)/a and 0.01 cm/a higher than that of freezing in the horizontal and vertical dimensions,respectively.Moreover,there were notable shifts in the melting and freezing of Arctic sea ice in 1997/2003 and 2000/2004,respectively,in the horizontal/vertical dimension. 展开更多
关键词 Arctic sea ice sea ice area sea ice thickness spatiotemporal variation freeze-thaw asymmetry
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Enhancing the Goos-Hänchen shift based on quasi-bound states in the continuum through material asymmetric dielectric compound gratings
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作者 江孝伟 方彬 占春连 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期393-400,共8页
Quasi-bound state in the continuum(QBIC)resonance is gradually attracting attention and being applied in Goos-Hänchen(GH)shift enhancement due to its high quality(Q)factor and superior optical confinement.Current... Quasi-bound state in the continuum(QBIC)resonance is gradually attracting attention and being applied in Goos-Hänchen(GH)shift enhancement due to its high quality(Q)factor and superior optical confinement.Currently,symmetry-protected QBIC resonance is often achieved by breaking the geometric symmetry,but few cases are achieved by breaking the material symmetry.This paper proposes a dielectric compound grating to achieve a high Q factor and high-reflection symmetry-protectede QBIC resonance based on material asymmetry.Theoretical calculations show that the symmetry-protected QBIC resonance achieved by material asymmetry can significantly increase the GH shift up to-980 times the resonance wavelength,and the maximum GH shift is located at the reflection peak with unity reflectance.This paper provides a theoretical basis for designing and fabricating high-performance GH shift tunable metasurfaces/dielectric gratings in the future. 展开更多
关键词 bound state in the continuum Goos-Hänchen shift dielectric compound grating material asymmetry
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Contributors to tidal duration asymmetry with varied coastline configurations on western shelf of Yellow Sea
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作者 Xi Feng Zheng Li +3 位作者 Hui Feng Jia-yan Yang Shou-peng Xie Wei-bing Feng 《Water Science and Engineering》 EI CAS CSCD 2024年第1期1-12,共12页
Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is ... Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is the resilience to coastal flooding,which depends on the ability to predict tidal level.Tidal duration asymmetry(TDA)is a key parameter in determination of the arrival and duration of flood tides.This study selected the western inner shelf of the Yellow Sea(WYS)as the study area and investigated the responses of TDA to different shoreline configurations and relative sea level rise.The responses of TDA to shoreline reconstruction yielded spatial variability locally and remotely.In the nearshore area,the responses of TDA to the complex ocean environment mainly originated from the combined functions of reflection,bottom friction,and advection,which controlled the energy transfer from M2 or S2 constituents to their overtides or compound tides.The sensitivity of TDA to coastline typologies was not limited to coastal waters but could stretch over the entire inner shelf.The vulnerability of tidal responses was due to the displacement of the M2 amphidrome of the Kelvin wave on the WYS,which in turn changed tidal energy fluxes over the regime.The relative sea level rise could intensify the feedback of TDA to seawalls and land reclamation. 展开更多
关键词 Tidal duration asymmetry Western inner shelf of Yellow Sea Natural restoration Relative sea level rise Tidal amphidrome
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The dawn−dusk asymmetry in mesosphere and lower thermosphere temperature disturbances during geomagnetic storms at high latitude
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作者 GuanChun Wei JianYong Lu +2 位作者 Fen Tang JingYuan Li Meng Sun 《Earth and Planetary Physics》 EI CAS CSCD 2024年第2期356-367,共12页
Utilizing observations by the Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)instrument,we quantitatively assessed the dawn-dusk asymmetry in temperature disturbances within the high-latitude mes... Utilizing observations by the Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)instrument,we quantitatively assessed the dawn-dusk asymmetry in temperature disturbances within the high-latitude mesosphere and lower thermosphere(MLT)during the main phase of geomagnetic storms in this study.An analysis of five geomagnetic superstorm events indicated that during the main phase,negative temperature disturbances were more prevalent on the dawn side than on the dusk side in the high-latitude MLT region.Results of a statistical analysis of 54 geomagnetic storm events also revealed a notable disparity in temperature disturbances between the dawn and dusk sides.At high latitudes,38.2%of the observational points on the dawn side exhibited negative temperature disturbances(less than−5 K),whereas on the dusk side,this percentage was only 29.5%.In contrast,at mid-latitudes,these proportions were 34.1%and 36.5%,respectively,showing no significant difference.We also conducted a statistical analysis of temperature disturbances at different altitudes,which revealed an increase in the proportion of warming disturbances with altitude.Conversely,the proportion of cooling disturbances initially rose with altitude,reaching a peak around 105 km,and subsequently decreased.These temperature disturbance differences could be explained by the day-night asymmetry in vertical wind disturbances during storm conditions. 展开更多
关键词 DAWN dusk asymmetry SABER(Sounding of the Atmosphere using Broadband Emission Radiometry) geomagnetic storms mesosphere and lower thermosphere
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Research on the Evaluation System of Community Daycare Center Planning and Implementation from the Perspective of Subject-Object Relationships
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作者 Tijin Gui 《Journal of Architectural Research and Development》 2024年第3期117-127,共11页
Through literature review,we found that evaluations of urban planning implementation often focus narrowly on either the subject(stakeholders)or the object(projects),while micro-level aspects such as site selection and... Through literature review,we found that evaluations of urban planning implementation often focus narrowly on either the subject(stakeholders)or the object(projects),while micro-level aspects such as site selection and construction are primarily considered within the context of planning implementation.There is insufficient research on the evaluation of implementation.Community daycare centers play a crucial role in the community home care model,yet there is relatively little research on their usage efficiency,satisfaction levels,and spatial evaluation of planning implementation.Based on the theoretical understanding of the human environment,including the subject,object,and their interactions,an evaluation system for the planning and implementation of community day care centers was constructed,incorporating subjective evaluation,objective evaluation,and comparative analysis. 展开更多
关键词 subject-object relationship Daycare center Planning implementation Evaluation system
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Macroeconomic Asymmetries in the Eurozone Countries in the Time of Financial Crisis
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作者 Asimakis Tamourantzis 《Economics World》 2024年第2期92-107,共16页
This paper seeks to highlight the macroeconomic asymmetries and social impacts among eurozone countries which occurred during the time of the financial crisis,emphasising the urgent need to revise the framework of eco... This paper seeks to highlight the macroeconomic asymmetries and social impacts among eurozone countries which occurred during the time of the financial crisis,emphasising the urgent need to revise the framework of economic governance.The analysis focuses on the growing macroeconomic and social imbalances on a representative sample of selected eurozone member-states(Euro(€)North and Euro(€)South)which had posed a threat to economic sustainability and social coherence. 展开更多
关键词 EUROZONE economic inequality macroeconomic asymmetries social imbalances economic governance
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Planar scintigraphy in assessment of mandibular asymmetry: Unilateral condylar hyperplasia vs asymmetric mandibular hyperplasia
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作者 Lo John Yau Yat Yin +1 位作者 Yeung Wai Chow David Cheung Lim Kwong 《Journal of Biomedical Science and Engineering》 2012年第12期836-844,共9页
Objectives: To 1) explore the planar scintigraphic findings in asymmetry patients caused by unilateral condylar hyperplasia (UCH) or asymmetric mandibular hyperplasia (AMH);2) develop a local agecondylar activity refe... Objectives: To 1) explore the planar scintigraphic findings in asymmetry patients caused by unilateral condylar hyperplasia (UCH) or asymmetric mandibular hyperplasia (AMH);2) develop a local agecondylar activity reference norm;and 3) check the accuracy of the new norm and compare with other analytical methods. Material and Method: Chinese patients with mandibular asymmetry and scintigraphic findings available were recruited. Clinical, radiographic records and scintigraphic condylar activity ratio (CAR) were studied. Regression analysis was performed to quantify the relationship between age and CAR to develop a new norm. The sensitivity of condylar activity assessment using a) traditional norm;b) new norm;and c) percentile difference was compared. In patients with serial data available, longitudinal analysis of the scintigraphic changes were checked. Result: 109 patients were eligible for the study. Significant difference in CAR was noted between UCH and AMH patients. Linear relationship was observed between age and CAR. A new norm of the age-CAR was established, which showed improved sensitivity in condylar activity prediction in UCH and AMH when compared with traditional norm. Relative to percentile difference, the sensitivity of new norm was lower in AMH but not in UCH patients. Serial analysis revealed gradual decline in CAR with minimal change in percentile difference. Conclusion and Clinical Relevance: There is difference in scintigraphic condylar activity between UCH and AMH patients. A norm of age-CAR relationship was established, which showed improved sensitivity in condylar activity prediction in UCH patients. Further study is required to confirm the role of scintigraphy in AMH. 展开更多
关键词 cintigraphy Bone SCAN FACIAL asymmetry MANDIBULAR asymmetry UNILATERAL Condylar HYPERPLASIA
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Tension-compression asymmetry and corresponding deformation mechanism in ZA21 magnesium bars with bimodal structure 被引量:2
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作者 Yujiao Wang Yun Zhang Haitao Jiang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第1期92-103,共12页
We investigated the asymmetric tension-compression(T-C)behavior of ZA21 bars with bimodal and uniform structures through axial tension and compression tests.The results show that the yield strengths of bars having bim... We investigated the asymmetric tension-compression(T-C)behavior of ZA21 bars with bimodal and uniform structures through axial tension and compression tests.The results show that the yield strengths of bars having bimodal structure are 206.42 and 140.28 MPa under tension and compression,respectively,which are higher than those of bars having uniform structure with tensile and compressive yield strength of 183.71 and 102.86 MPa,respectively.Prismatic slip and extension twinning under tension and basal slip and extension twinning under compression dominate the yield behavior and induce the T-C asymmetry.However,due to the basal slip activated in fine grains under tension and the inhibition of extension twinning by fine grains under compression,the bimodal structure possesses a lower T-C asymmetry(0.68)compared to the uniform structure(0.56).Multiple extension twins occur during deformation,and the selection of twin variants depends on the Schmid factor of the six variants activated by parent grains.Furthermore,the strengthening effect of the bimodal structure depends on the grain size and the ratio of coarse and fine grains. 展开更多
关键词 bimodal structure deformation mechanism Hall-Petch relationship tension-compression asymmetry twin variant selection
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A three-dimensional numerical study on the effect of geometric asymmetry on arcjet thruster performance 被引量:2
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作者 Hari Prasad NANDYALA Amit KUMAR Jayachandran THANKAPPAN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第5期131-146,共16页
In an arcjet thruster,the cathode and constrictor degrade with time,and the electrical arc discharge may become unsymmetrical.In this work,a three-dimensional numerical model of a hydrogen plasma arcjet is developed a... In an arcjet thruster,the cathode and constrictor degrade with time,and the electrical arc discharge may become unsymmetrical.In this work,a three-dimensional numerical model of a hydrogen plasma arcjet is developed and validated to study the effect of unsymmetrical electric arc discharge on thruster performance.The unsymmetrical arc discharge is realized by introducing a radial shift of the cathode so that the cathode tip offset is 80μm(25%of the constrictor radius).Simulations are conducted for both axially centered cathode(coaxial)and off-centered cathode(non-coaxial)configurations with identical propellant flow rates and input current.Simulations show asymmetrical arc discharge in the non-coaxial cathode configuration,resulting in azimuthally asymmetric Joule heating,species concentrations,and velocity field.This asymmetry continues as the plasma expands in the divergent section of the nozzle.Temperature,species concentrations,and axial velocity exhibit asymmetric radial distribution at the nozzle exit.The computed Joule heating was found to reduce with cathode shift,and consequently,the thrust and specific impulse of the thruster was decreased by about 6.6%.In the case of the non-coaxial cathode,geometric asymmetry also induces a small side thrust. 展开更多
关键词 ARCJET geometric asymmetry 3D numerical modelling space electric propulsion HYDROGEN
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Loading direction dependence of asymmetric response of pyramidal slip in rolled AZ31 magnesium alloy 被引量:1
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作者 Yuzhi Zhu Dewen Hou +1 位作者 Kaixuan Chen Zidong Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第10期3634-3641,共8页
Textured magnesium alloys usually exhibit anisotropic mechanical behavior due to the asymmetric activation of different twinning and slipping modes.This work focuses on the pyramidal slip responses of rolled AZ31 magn... Textured magnesium alloys usually exhibit anisotropic mechanical behavior due to the asymmetric activation of different twinning and slipping modes.This work focuses on the pyramidal slip responses of rolled AZ31 magnesium alloy under two loading conditions,compressive and tensile loading along the normal direction.Under the condition where the compressive loading direction is closely parallel to the c-axis of the unit cell,tensile twinning and basal slips are prohibited, dislocations then active and tend to accumulate at grain boundaries and form dislocation walls.Meanwhile,these dislocations exhibit zigzag morphologies,which result from the cross-slip from {10■1} first-order pyramidal plane to {11■2} second-order pyramidal plane,then back to {10■1} first-order pyramidal plane.Under the condition where tensile twins are prevalent,{10■1} first-order and {11■2} second-order pyramidal dislocations are favorable to be activated.Both types of dislocations behave climb-like dissociations onto the basal plane,forming zigzag dislocations. 展开更多
关键词 MAGNESIUM pyramidal slip asymmetry CROSS-SLIP
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Underlying mechanisms of variation in yield asymmetry and strain hardening behavior of extruded pure Mg with Gd addition 被引量:1
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作者 Gyo Myeong Lee Sung Hyuk Park 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第6期2165-2181,共17页
Effects of Gd addition on the strain hardening behavior and yield asymmetry of pure Mg are investigated by subjecting extruded pure Mg,Mg–5Gd,and Mg–15Gd(all in wt%)to tension and compression tests along the extrusi... Effects of Gd addition on the strain hardening behavior and yield asymmetry of pure Mg are investigated by subjecting extruded pure Mg,Mg–5Gd,and Mg–15Gd(all in wt%)to tension and compression tests along the extrusion direction(ED).As the amount of Gd added to pure Mg increases,the basal texture tilts toward the ED and the distribution of c-axes of grains becomes randomized.Under tension,the strain hardening rates of all the materials decrease until fracture.However,under compression,the strain hardening rate increases in the early stage of deformation in pure Mg and Mg–5Gd,whereas it continuously decreases in Mg–15Gd.Pure Mg exhibits considerably high tension-compression yield asymmetry,with a compressive yield strength(CYS)to tensile yield strength(TYS)ratio of 0.4.In contrast,Mg–5Gd exhibits excellent yield symmetry with CYS/TYS of 0.9 and Mg–15Gd exhibits reversed yield asymmetry with CYS/TYS of 1.2.Underlying mechanisms of these drastically different Gd-addition-induced deformation behaviors of the materials are discussed in terms of the crystallographic distribution of grains and the relative activation stresses of basal slip,prismatic slip,pyramidal slip,and{10–12}twinning under tension and compression. 展开更多
关键词 Pure Mg Gd addition TEXTURE Yield asymmetry Activation stress
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Promoting hybrid twins structure to reduce yield asymmetry of rolled AZ31 plates by combining side-rolling and torsion 被引量:1
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作者 Bo Song Meng Wang +4 位作者 Ruolan Shi Zhiwen Du Ning Guo Fang Wang Shengfeng Guo 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第6期2096-2105,共10页
In this work,an as-rolled AZ31 square bar with c-axis//ND(normal direction)texture was used.Side-rolling and reciprocating torsion were performed to treat the bar.Microstructure evolution and tensile-compressive prope... In this work,an as-rolled AZ31 square bar with c-axis//ND(normal direction)texture was used.Side-rolling and reciprocating torsion were performed to treat the bar.Microstructure evolution and tensile-compressive properties were investigated in detail.Initial rolled AZ31 bar exhibits a large yield asymmetry along the rolling direction(RD).Reciprocating torsion can generate extension twins to introduce twin boundaries and twin-texture.The twin structure can reduce yield asymmetry.However,only limited regions in the rolled AZ31 bar can be twinned during torsion.Pre-side-rolling along the transverse direction(TD)can generate two texture components(c-axis//TD texture and c-axis//ND texture)by introducing profuse{10–12}twins.Such dual texture components help increase the regions which are favorable for twinning during torsion.Finally,combining side-rolling and reciprocating torsion generates hybrid{10–12}twins structure on the entire cross-section,resulting in a remarkably low yield asymmetry.The relevant mechanisms were discussed in detail. 展开更多
关键词 AZ31 Square section TORSION Hybrid twins Orientation Yield asymmetry
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Asymmetry of Salinity Variability in the Tropical Pacific during Interdecadal Pacific Oscillation Phases 被引量:1
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作者 Hai ZHI Zihui YANG +4 位作者 Rong-Hua ZHANG Pengfei LIN Jifeng QI Yu HUANG Meng DONG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第7期1269-1284,共16页
It has been recognized that salinity variability in the tropical Pacific is closely related to the Interdecadal Pacific Oscillation(IPO).Here,we use model simulations from 1900 to 2017 to illustrate obvious asymmetrie... It has been recognized that salinity variability in the tropical Pacific is closely related to the Interdecadal Pacific Oscillation(IPO).Here,we use model simulations from 1900 to 2017 to illustrate obvious asymmetries of salinity variability in the tropical Pacific during positive and negative IPO phases.The amplitude of salinity variability in the tropical Pacific during positive IPO phases is larger than that during negative IPO phases,with a more westward shift of a large Sea Surface Salinity(SSS)anomaly along the equator.Salinity budget analyses show that the asymmetry of salinity variability during positive and negative IPO phases is dominated by the difference in the surface forcing associated with the freshwater flux[FWF,precipitation(P)minus evaporation(E)],with a contribution of 40%–50%near the dateline on the equator.Moreover,the relationships between the salinity variability and its budget terms also show differences in their leadlag correlations during positive and negative IPO phases.These differences in salinity variability during different IPO phases produce asymmetric effects on seawater density which can reduce or enhance upper-ocean stratification.Therefore,the salinity effects may modulate the intensity of El Nino-Southern Oscillation(ENSO),resulting in an enhanced(reduced)El Nino but a reduced(enhanced)La Ni?a during positive(negative)IPO phases by 1.6℃psu^(-1)(1.3℃psu^(-1)),respectively.It is suggested that the asymmetry of salinity variability may be related to the recent change in ENSO amplitude associated with the IPO,which can help elucidate ENSO diversity. 展开更多
关键词 salinity variability asymmetry upper-ocean stratification Interdecadal Pacfic Oscillation tropical Pacific
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Asymmetric Environmental Regulation:Mechanism and a Yardstick Phenomenon 被引量:1
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作者 Yu Yazhuo Zhang Huilin Zhang Pingdan 《China Economist》 2023年第1期87-107,共21页
In discussing the policy effects of environmental regulation,we should focus not only on whether environmental regulation helps improve the environmental and economic performance of firms,but also on how such improvem... In discussing the policy effects of environmental regulation,we should focus not only on whether environmental regulation helps improve the environmental and economic performance of firms,but also on how such improvement is materialized,i.e.whether the obsolete mode of production is reversed.After matching the database of China’s industrial enterprises with that of pollution emissions from these industrial enterprises,this paper identifies the asymmetric scope of clean production standards to test the effect of environmental regulation on the total factor productivity(TFP)of the industrial enterprises.Our empirical research finds that the implementation of clean production standards may induce TFP improvement.However,such improvement only occurs for polluters who cannot or who barely meet clean production standards and does little to improve the production standards of polluters with low pollution emission,reflecting the yardstick phenomenon of the asymmetric environmental regulation policy effect:While polluters are forced to improve,clean enterprises that pollute less are more likely to take no action.Further research finds that such TFP improvement is materialized primarily by means of overall firm optimization;the compensation effect is insignificant and does not reverse the backward mode of production.Polluters cope with the implementation of clean production standards by purchasing more equipment and expanding capacity,which adds to the tension between the expansion of capacity and the abatement of pollution emission. 展开更多
关键词 ENVIRONMENTAL REGULATION CLEAN production STANDARDS TFP asymmetry yardstick phenomenon
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Effect of Cadmium on the Developmental Instability of Anabas testudineus through Evaluation of Fluctuating Asymmetry of Eye Diameter
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作者 Fazlin Hazirah Mohd Sharifah Nadrah Syed Idrus +1 位作者 Mohd Riduan Abdullah Mohd Sham Othman 《Journal of Environmental Protection》 CAS 2023年第5期392-403,共12页
Biomonitoring using fish has been a popular method of assessing the toxic effects of cadmium concentrations of cadmium in water bodies and has led to bioaccumulation in fish contributing to various morphological alter... Biomonitoring using fish has been a popular method of assessing the toxic effects of cadmium concentrations of cadmium in water bodies and has led to bioaccumulation in fish contributing to various morphological alterations. Among the known effects of these alterations is developmental instability via fluctuating asymmetry (FA). The utilization of FA data is a simple yet effective method to evaluate the toxic effects of cadmium on the stability of development. This study used climbing perch (Anabas testudieneus) to assess the FA in the diameter of the eye because of low-level cadmium exposure. The left and right sides of the traits were measured once every four weeks for 16 weeks. The average measurements from both sides of the traits were used to calculate the FA value. Results found that the highest mean FA for the diameter of the eye was obtained in the highest treatment group, 0.015 mg/L. The results also indicate that increasing concentrations of cadmium exposure had a statistically significant effect on the FA of eye diameter. There was also a statistically significant interaction between the duration of exposure and treatment groups in FA of the diameter of the eye. The results from the study indicate that prolonged exposure to sub-lethal concentrations of cadmium can cause significant effects on the normal development of eyes in Anabas testudineus. This study can add to the body of research regarding fluctuating asymmetry as a tool to study developmental toxicants and assess other bilateral organs. 展开更多
关键词 BIOMONITORING CADMIUM Eye Fluctuating asymmetry Anabas testudineus
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Functional role of frontal electroencephalogram alpha asymmetry in the resting state in patients with depression:A review
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作者 Yu-Hong Xie Ye-Min Zhang +2 位作者 Fan-Fan Fan Xi-Yan Song Lei Liu 《World Journal of Clinical Cases》 SCIE 2023年第9期1903-1917,共15页
Depression is a psychological disorder that affects the general public worldwide.It is particularly important to make an objective and accurate diagnosis of depression,and the measurement methods of brain activity hav... Depression is a psychological disorder that affects the general public worldwide.It is particularly important to make an objective and accurate diagnosis of depression,and the measurement methods of brain activity have gradually received increasing attention.Resting electroencephalogram(EEG)alpha asymmetry in patients with depression shows changes in activation of the alpha frequency band of the left and right frontal cortices.In this paper,we review the findings of the relationship between frontal EEG alpha asymmetry in the resting state and depression.Based on worldwide studies,we found the following:(1)Compared with individuals without depression,those with depression showed greater right frontal EEG alpha asymmetry in the resting state.However,the pattern of frontal EEG alpha asymmetry in the resting state in depressive individuals seemed to disappear with age;(2)Compared with individuals without maternal depression,those with maternal depression showed greater right frontal EEG alpha asymmetry in the resting state,which indicated that genetic or experience-based influences have an impact on frontal EEG alpha asymmetry at rest;and(3)Frontal EEG alpha asymmetry in the resting state was stable,and little or no change occurred after antidepressant treatment.Finally,we concluded that the contrasting results may be due to differences in methodology,clinical characteristics,and participant characteristics. 展开更多
关键词 DEPRESSION Frontal electroencephalogram alpha asymmetry Frontal asymmetry Resting state Neurological indicator
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Improved super-elastic Ti-Ni alloy wire for treating adult skeletal class III with facial asymmetry:A case report
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作者 Chun-Yi Huang Yuan-Hou Chen +1 位作者 Chih-Chieh Lin Jian-Hong Yu 《World Journal of Clinical Cases》 SCIE 2023年第21期5147-5159,共13页
BACKGROUND Correcting severe skeletal class III malocclusion with facial asymmetry in adults through orthodontic treatment alone is difficult.CASE SUMMARY In this case report,we describe orthodontic treatment and lowe... BACKGROUND Correcting severe skeletal class III malocclusion with facial asymmetry in adults through orthodontic treatment alone is difficult.CASE SUMMARY In this case report,we describe orthodontic treatment and lower incisor extraction without orthognathic surgery for a 27-year-old man with a transverse discrepancy.The extraction sites were closed using an elastic chain.The use of intermaxillary elastics,improved super-elastic Ti-Ni alloy wire,and unilateral multibend edgewise arch wire was crucial for correcting facial asymmetry and the midline deviation.CONCLUSION After treatment,the patient had a more symmetrical facial appearance,acceptable overjet and overbite,and midline coincidence.The treatment results remained stable 3 years after treatment.This case report demonstrates that a minimally invasive treatment can successfully correct severe skeletal class III malocclusion with facial asymmetry. 展开更多
关键词 Skeletal class III malocclusion Facial asymmetry DENTISTRY ORTHODONTICS Facial asymmetry Lower incisor extraction Case report
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Influence of coupling asymmetry on signal amplification in a three-node motif
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作者 梁晓明 方超 +1 位作者 张希昀 吕华平 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期239-243,共5页
The three-node feedforward motif has been revealed to function as a weak signal amplifier. In this motif, two nodes(input nodes) receive a weak input signal and send it unidirectionally to the third node(output node).... The three-node feedforward motif has been revealed to function as a weak signal amplifier. In this motif, two nodes(input nodes) receive a weak input signal and send it unidirectionally to the third node(output node). Here, we change the motif's unidirectional couplings(feedforward) to bidirectional couplings(feedforward and feedback working together).We find that a small asymmetric coupling, in which the feedforward effect is stronger than the feedback effect, may enable the three-node motif to go through two distinct dynamic transitions, giving rise to a double resonant signal response. We present an analytical description of the double resonance, which agrees with the numerical findings. 展开更多
关键词 network motif SYNCHRONIZATION coupling asymmetry signal amplification
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