This study proposes a new post-tensioned precast bridge column(PT-PBC)with a socket connection.Compared to conventional PBCs connected by PT tendons,the combination of the PT tendons with the socket connection can avo...This study proposes a new post-tensioned precast bridge column(PT-PBC)with a socket connection.Compared to conventional PBCs connected by PT tendons,the combination of the PT tendons with the socket connection can avoid tensioning the PT tendons on site,which further accelerates construction speed while improving construction quality and safety.In addition,compared to conventional PBCs with a socket connection,a rocking interface can avoid the formation of a plastic hinge in a column,which greatly alleviates seismic damage to that area.One specimen for quasi-static testing is used to validate the feasibility of this connection type.Subsequently,finite element models(FEM)are established to systematically predict the responses of the proposed columns under lateral cyclic loading.The accuracy of the FEM is verified through quasistatic testing.Next,the influences of the key design parameters of the PT-PBC,including the area ratio and prestress level of the PT tendons,the area ratio of energy dissipation(ED)steel rebars,and the total axial compression ratio on the seismic performances of PT-PBC are systematically investigated.The use of shape memory alloy(SMA)rods as energy dissipation devices and their performances also are investigated.The results show that increasing the area ratio and prestress level of PT tendons has an overall positive impact on the self-centering capacity of the column.The prestress level of PT tendons should be kept between 35%and 55%,depending on different conditions.The total compression axial ratio of the columns should be maintained between 0.3 and 0.4.Both ED steel rebars and SMA rods can boost the column’s energy dissipation capacity,while SMA rods can reduce residual deformation due to their inherent mechanical properties.展开更多
Background:Social connection is widely recognized as a protective determinant of health,yet its direct and indirect effects on mental health remain underexplored.This study examines the relationship between social con...Background:Social connection is widely recognized as a protective determinant of health,yet its direct and indirect effects on mental health remain underexplored.This study examines the relationship between social connection and mental health,focusing on the mediating role of quality of life(QoL)and the moderating effect of regional differences.Methods:We analyzed data from the 2019 Korean Community Health Survey,comprising 229,099 adults.Mental health was assessed through validated measures of depressive symptoms and psychological well-being.Social connection was measured using indicators of interpersonal ties and community participation,and QoL was assessed via self-reported health-related satisfaction across major life domains.Analytical procedures included mediation modeling and subgroup analyses by region,with significance levels set at p<0.05.Results:The results indicate that social connections are significantly associated with lower stress levels and reduced depressive symptoms,with QoL playing a critical mediating role.Notably,the indirect effect of social connection on mental health via QoL is stronger in rural areas compared to urban regions,highlighting the importance of social cohesion and community support in mental well-being.Among 203,567 adults,greater social participation was associated with lower subjective stress(total effect=−0.052,p<0.001)and fewer depressive symptoms(PHQ-9 total effect=−0.308,p<0.001).QoL significantly mediated these associations,with the strongest indirect pathways observed through usual activities(19.2%for stress;27.6%for depression)and mobility(24.4%for depression).Regional analysis showed stronger mediation in rural areas(up to 26.8%for stress and 32.6%for depression)than in urban areas(8–16%and 14.9–23%).Direct effects remained significant,indicating partial mediation.These findings highlight that social participation enhances mental health directly and indirectly through QoL,particularly in rural contexts.Conclusions:Social connection contributes to better mental health both directly and indirectly through improved QoL,with stronger effects observed in rural communities.These findings highlight the importance of fostering social cohesion and enhancing life quality as strategies for improving population mental health.Policy interventions should adopt context-sensitive approaches that account for regional differences in social resources and service availability.展开更多
In two-scale topology optimization,enhancing the connectivity between adjacent microstructures is crucial for achieving the collaborative optimization of micro-scale performance and macro-scale manufacturability.This ...In two-scale topology optimization,enhancing the connectivity between adjacent microstructures is crucial for achieving the collaborative optimization of micro-scale performance and macro-scale manufacturability.This paper proposes a two-scale concurrent topology optimization strategy aimed at improving the interface connection strength.This method employs a parametric approach to explicitly divide the micro-design domain into a“boundary connection region”and a“free design domain”at the initial stage of optimization.The boundary connection region is used to generate a connection layer that enhances the interface strength,while the free design domain is not constrained by this layer,thus fully exploiting the design potential of the material layout.During the optimization process,the solid isotropic material with penalization(SIMP)method is first used to optimize the material distribution in the free design domain,and filtering and projection techniques are employed to alleviate numerical instability and obtain a clear topological structure.Subsequently,the effective performance of the microstructure is calculated through homogenization and transferred to the macro-scale for global response analysis.Throughout the iterative process,the geometry of the connection layer remains unchanged,and only the free design domain is optimized,thereby achieving a balance between high performance and good manufacturability.The effectiveness of the proposed method is verified through numerical examples.展开更多
To achieve efficient connection and integrity in prefabricated frame structures,a novel beam-column connection between prefabricated steel-reinforced concrete(SRC)columns and cast-in-situ reinforced concrete(RC)beams ...To achieve efficient connection and integrity in prefabricated frame structures,a novel beam-column connection between prefabricated steel-reinforced concrete(SRC)columns and cast-in-situ reinforced concrete(RC)beams is proposed.Four connection specimens with varying thicknesses of connecting cover plates were designed and fabricated.Low-cycle reversed loading tests were conducted to obtain mechanical performance data,allowing for analysis of behavioral patterns,including load-displacement hysteresis curves,skeleton curves,load-carrying capacity,deformation performance,energy dissipation capacity,and stiffness degradation.Test results indicate that properly designed prefabricated connections exhibit mechanical properties comparable to those of cast-in-situ concrete connections.The hysteresis curves of the prefabricated connections are well-shaped,with nearly no reduction in load-carrying capacity and deformation performance,demonstrating excellent seismic behavior.The findings provide a theoretical basis and reference for the design of prefabricated concrete frame structures.展开更多
Background:Brain volume measurement serves as a critical approach for assessing brain health status.Considering the close biological connection between the eyes and brain,this study aims to investigate the feasibility...Background:Brain volume measurement serves as a critical approach for assessing brain health status.Considering the close biological connection between the eyes and brain,this study aims to investigate the feasibility of estimating brain volume through retinal fundus imaging integrated with clinical metadata,and to offer a cost-effective approach for assessing brain health.Methods:Based on clinical information,retinal fundus images,and neuroimaging data derived from a multicenter,population-based cohort study,the Kai Luan Study,we proposed a cross-modal correlation representation(CMCR)network to elucidate the intricate co-degenerative relationships between the eyes and brain for 755 subjects.Specifically,individual clinical information,which has been followed up for as long as 12 years,was encoded as a prompt to enhance the accuracy of brain volume estimation.Independent internal validation and external validation were performed to assess the robustness of the proposed model.Root mean square error(RMSE),peak signal-tonoise ratio(PSNR),and structural similarity index measure(SSIM)metrics were employed to quantitatively evaluate the quality of synthetic brain images derived from retinal imaging data.Results:The proposed framework yielded average RMSE,PSNR,and SSIM values of 98.23,35.78 d B,and 0.64,respectively,which significantly outperformed 5 other methods:multi-channel Variational Autoencoder(mcVAE),Pixelto-Pixel(Pixel2pixel),transformer-based U-Net(Trans UNet),multi-scale transformer network(MT-Net),and residual vision transformer(ResViT).The two-(2D)and three-dimensional(3D)visualization results showed that the shape and texture of the synthetic brain images generated by the proposed method most closely resembled those of actual brain images.Thus,the CMCR framework accurately captured the latent structural correlations between the fundus and the brain.The average difference between predicted and actual brain volumes was 61.36 cm~3,with a relative error of 4.54%.When all of the clinical information(including age and sex,daily habits,cardiovascular factors,metabolic factors,and inflammatory factors)was encoded,the difference was decreased to 53.89 cm~3,with a relative error of 3.98%.Based on the synthesized brain magnetic resonance images from retinal fundus images,the volumes of brain tissues could be estimated with high accuracy.Conclusion:This study provides an innovative,accurate,and cost-effective approach to characterize brain health status through readily accessible retinal fundus images.展开更多
Optic nerve injury leads to axonal degeneration and the death of retinal ganglion cells,which ultimately causes vision loss.Notably,current treatments are limited.In the present study,we explored whether neurogenic di...Optic nerve injury leads to axonal degeneration and the death of retinal ganglion cells,which ultimately causes vision loss.Notably,current treatments are limited.In the present study,we explored whether neurogenic differentiation factor 1(NeuroD1 or ND1)overexpression in retinal Müller cells may repair the retina after optic nerve crush in mice.Adult mice were subjected to optic nerve crush followed by intravitreal AAV-7m8-GFAP-GFP-ND1 virus injection.Immunofluorescent staining,multi-electrode array recording,electroretinogram,and visual behavior tests were then performed to examine retinal and optic nerve structure and retinal function at various post-optic nerve crush and virus injection times.Western blot analysis and quantitative reverse transcription polymerase chain reaction were performed to explore the possible mechanisms.Compared with the control virus,specific overexpression of ND1 in Müller cells greatly improved the light responses of retinal ganglion cells and retinal neurons in optic nerve crush-injured mice as early as 1-2 weeks post-virus injection and lasted for up to 4 weeks.Neuronal survival in the ganglion cell layer and synaptic connections in the inner retina were slightly improved at 2 weeks;however,visual behavior,retinal ganglion cell survival,and optic nerve structure were not improved.ND1 transiently enhanced glial cell-derived neurotrophic factor expression in the optic nerve crush-injured retina but hardly inhibited retinal inflammation within 2 weeks.Together,our data indicate that ND1 overexpression in Müller cells improves retinal function in the optic nerve crush-injured retina,and suggest that its neuroprotective effect may be caused by enhanced glial cell-derived neurotrophic factor release.展开更多
For the ultra HVDC(UHVDC)with the hierarchical connection mode at the inverter side,considering the change of the Thevenin equivalent parameters(TEP)of post-fault AC grid,a coordinated control strategy to the subseque...For the ultra HVDC(UHVDC)with the hierarchical connection mode at the inverter side,considering the change of the Thevenin equivalent parameters(TEP)of post-fault AC grid,a coordinated control strategy to the subsequent commutation failure(SCF)at both layers is newly proposed.The originality of this work is manifested in three aspects.1)The mechanism of the SCF at the fault layer is newly found by deriving the analytical expression of the extinction angle with the TEP,and that at the non-fault layer is newly found by the voltage-time area theory with the DC current coupling.2)An estimation model for the TEPs of two AC grids at the inverter side is proposed with the post-fault quantities.To address the random noise and inaccurate measurement data,an adaptive robust least squares method based on the median principle is proposed to solve the TEP model.3)A coordinated control strategy with the estimated TEP is proposed to compensate for the extinction angle at the fault layer and limit the DC current at the non-fault layer,thus suppressing the SCF.The simulation results verify the suppression effect of the proposed control on the SCF under different fault conditions.展开更多
The Wilczek–Zee connection(WZC)is a key concept in the study of topology of quantum systems.Here,we introduce the double Wilczek–Zee connection(DWZC)which naturally appears in the pure-state quantum geometric tensor...The Wilczek–Zee connection(WZC)is a key concept in the study of topology of quantum systems.Here,we introduce the double Wilczek–Zee connection(DWZC)which naturally appears in the pure-state quantum geometric tensor(QGT),another important concept in the field of quantum geometry.The DWZC is Hermitian with respect to the two integer indices,just like the original Hermitian WZC.Based on the symmetric logarithmic derivative operator,we propose a mixed-state quantum geometric tensor.Using the symmetric properties of the DWZC,we find that the real part of the QGT is connected to the real part of the DWZC and the square of eigenvalue differences of the density matrix,whereas the imaginary part can be given in terms of the imaginary part of the DWZC and the cube of the eigenvalue differences.For density matrices with full rank or no full rank,the QGT can be given in terms of real and imaginary parts of the DWZC.展开更多
Founded in September 2020,the International SparkLink Alliance(iSLA)now has approximately 1,200 members in diverse sectors including terminals,homes,vehicles,manufacturing,transportation,finance and healthcare.The iSL...Founded in September 2020,the International SparkLink Alliance(iSLA)now has approximately 1,200 members in diverse sectors including terminals,homes,vehicles,manufacturing,transportation,finance and healthcare.The iSLA has established a technical standards system for wireless short-range communication covering full-stack standards such as the end-to-end protocol system.展开更多
Preventive maintenance(PM)enhances the reliability of an ultra-high-voltage DC(UHVDC)line.However,it introduces new states and complicates the task of determining the reliability parameters of the component with PM.Th...Preventive maintenance(PM)enhances the reliability of an ultra-high-voltage DC(UHVDC)line.However,it introduces new states and complicates the task of determining the reliability parameters of the component with PM.The hierarchical connection(HC)of the inverter improves the flexibility of UHVDC,but the state spaces of the inverter and UHVDC-HC are determined by capacity distribution between the high terminal(HT)and low terminal(LT),which has not been studied yet.In this paper,the reliability of UHVDC-HC with the PM is studied.First,with the impact of PM described by a nonlinear coefficient,the state space of the components with PM is aggregated.It is the same size as without PM.The only difference is the transition rate.Second,considering power distribution between the HT/LT and its dependence on the state of the rectifier,new capacity levels of HT/LT,e.g.,75%/2,50%/3,are defined.Third,with capacity levels of the HT/LT differentiated,2 existing reliability indices are extended,and 2 are newly defined.Finally,a sensitivity model of the reliability of the UHVDC-HC to its parameters and the PM period is proposed.展开更多
To improve the fault diagnosis accuracy of a PV grid-connected inverter,a PV grid-connected inverter data diagnosis method based on MPA-VMD-PSO-BiLSTM is proposed.Firstly,unlike the traditional VMD algorithm which rel...To improve the fault diagnosis accuracy of a PV grid-connected inverter,a PV grid-connected inverter data diagnosis method based on MPA-VMD-PSO-BiLSTM is proposed.Firstly,unlike the traditional VMD algorithm which relies on manual experience to set parameters(e.g.,noise tolerance,penalty parameter,number of decompositions),this paper achieves adaptive optimization of parameters through MPA algorithmto avoid the problemof feature information loss caused by manual parameter tuning,and adopts the improved VMD algorithm for feature extraction of DC-side voltage data signals of PV-grid-connected inverters;and then,adopts the PSO algorithm for theThen,the PSO algorithm is used to optimize the optimal batch size,the number of nodes in the hidden layer and the learning rate of the BiLSTM network,which significantly improves the model’s ability to capture the long-term dependent features of the PV inverter’s timing signals,to construct the PV grid-connected inverter prediction model of PSO-BiLSTM,and predict the capacitance value of the PVgrid-connected inverter.Finally,diagnostic experiments are carried out based on the expected capacitance value and the capacitance failure criterion.The results showthat compared with the traditional VMD algorithm,the MPA-optimised VMD improves the signal-to-noise ratio(SNR)of the signal decomposition from 28.5 to 33.2 dB(16.5%improvement).After combining with the PSO-BiLSTM model,the mean absolute percentage error(MAPE)of the fault diagnosis is reduced to 1.31%,and the coefficient of determination(R2)is up to 0.99.It is concluded that the present method has excellent diagnostic performance of PV grid-connected inverter data signals and effectively improves the accuracy of PV grid-connected inverter diagnosis.展开更多
Emerging contaminants(ECs)have raised global concern due to their adverse effect on ecosystems and human health.However,the occurrence and transport of ECs in stormwater remain unclear.The impact of ECs from stormwate...Emerging contaminants(ECs)have raised global concern due to their adverse effect on ecosystems and human health.However,the occurrence and transport of ECs in stormwater remain unclear.The impact of ECs from stormwater on surface water quality and ecosystem health is also poorly documented.In this review,we examined the variations in EC concentrations in surface water resulting from stormwater.During the wet weather,the concentrations of most investigated ECs,e.g.,microplastics,per-and polyfluoroalkyl substances,and vehicle-related compounds,significantly increase in surface water,indicating that stormwater may be a critical source of these contaminants.Furthermore,the potential pathways of ECs from stormwater enter surface water are outlined.Studies demonstrate that surface runoff and combined sewer overflows are important pathways for ECs,with discharges comparable to or exceeding those from wastewater treatment plants.Illicit connection also plays an important part in elevated EC concentrations in surface water.Overall,our findings underscore the importance of stormwater as a source for ECs in surface waters,and urge for increased emphasis on,and reinforcement of,stormwater monitoring and control measures to minimize the transport of ECs into receiving water bodies.展开更多
The Michelson Interferometer for Global High-resolution Thermospheric Imaging(MIGHTI)onboard the Ionospheric Connection Explorer(ICON)satellite offers the opportunity to investigate the altitude profile of thermospher...The Michelson Interferometer for Global High-resolution Thermospheric Imaging(MIGHTI)onboard the Ionospheric Connection Explorer(ICON)satellite offers the opportunity to investigate the altitude profile of thermospheric winds.In this study,we used the red-line measurements of MIGHTI to compare with the results estimated by Horizontal Wind Model 14(HWM14).The data selected included both the geomagnetic quiet period(December 2019 to August 2022)and the geomagnetic storm on August 26-28,2021.During the geomagnetic quiet period,the estimations of neutral winds from HWM14 showed relatively good agreement with the observations from ICON.According to the ICON observations,near the equator,zonal winds reverse from westward to eastward at around 06:00 local time(LT)at higher altitudes,and the stronger westward winds appear at later LTs at lower altitudes.At around 16:00 LT,eastward winds at 300 km reverse to westward,and vertical gradients of zonal winds similar to those at sunrise hours can be observed.In the middle latitudes,zonal winds reverse about 2-4 h earlier.Meridional winds vary more significantly than zonal winds with seasonal and latitudinal variations.According to the ICON observations,in the northern low latitudes,vertical reversals of meridional winds are found at 08:00-13:00 LT from 300 to 160 km and at around 18:00 LT from 300 to 200 km during the June solstice.Similar reversals of meridional winds are found at 04:00-07:00 LT from 300 to 160 km and at 22:00-02:00 LT from 270 to 200 km during the December solstice.In the southern low latitudes,meridional wind reversals occur at 08:00-11:00 LT from 200 to 160 km and at 21:00-02:00 LT from 300 to 200 km during the June solstice.During the December solstice,reversals of the meridional wind appear at 20:00-01:00 LT below 200 km and at 06:00-11:00 LT from 300 to 160 km.In the northern middle latitudes,the northward winds are dominant at 08:00-14:00 LT at 230 km during the June solstice.Northward winds persist until 16:00 LT at 160 and 300 km.During the December solstice,the northward winds are dominant from 06:00 to 21:00 LT.The vertical variations in neutral winds during the geomagnetic storm on August 26-28 were analyzed in detail.Both meridional and zonal winds during the active geomagnetic period observed by ICON show distinguishable vertical shear structures at different stages of the storm.On the dayside,during the main phase,the peak velocities of westward winds extend from a higher altitude to a lower altitude,whereas during the recovery phase,the peak velocities of the westward winds extend from lower altitudes to higher altitudes.The velocities of the southward winds are stronger at lower altitudes during the storm.These vertical structures of horizontal winds during the storm could not be reproduced by the HWM14 wind estimations,and the overall response to the storm of the horizontal winds in the low and middle latitudes is underestimated by HWM14.The ICON observations provide a good dataset for improving the HWM wind estimations in the middle and upper atmosphere,especially the vertical variations.展开更多
With the acceleration of urbanization,prefabricated bridges have become a significant choice for transportation infrastructure construction due to their environmental friendliness,efficiency,and reliable quality.Howev...With the acceleration of urbanization,prefabricated bridges have become a significant choice for transportation infrastructure construction due to their environmental friendliness,efficiency,and reliable quality.However,existing connection technologies still face shortcomings in construction efficiency,seismic performance,and cost control.This paper summarizes the process characteristics of commonly used connection technologies such as socket connections,grouted sleeve connections and corrugated pipe connections,and analyzes their seismic capacity and mechanical performance.In response to existing issues,two new technologies—separated steel connection and multi-chamber steel tube concrete connection—are proposed,and their comprehensive performance and economic efficiency are analyzed.The new connection technologies outperform traditional methods in construction efficiency,economic efficiency,and structural stability,with more reasonable force distribution,clearer load transfer paths,and significantly reduced overall costs.Existing technologies,such as socket connections,perform well in seismic performance but are complex to construct;grouted sleeve connections are mature in technology,but the quality of grouting is difficult to inspect.The separated steel connection and multi-chamber steel tube concrete connection technologies offer significant advantages.With the increasing demands for energy conservation and emission reduction,coupled with the rising labor costs,prefabricated bridge piers are undoubtedly poised to become one of the preferred technologies for bridge construction in China in the future.Therefore,in light of the current research landscape,this paper concludes by offering a forward-looking perspective on the development directions of connection methods for prefabricated bridge piers and identifying key areas for future research.展开更多
We present a gain adaptive tuning method for fiber Raman amplifier(FRA) using two-stage neural networks(NNs) and double weights updates. After training the connection weights of two-stage NNs separately in training ph...We present a gain adaptive tuning method for fiber Raman amplifier(FRA) using two-stage neural networks(NNs) and double weights updates. After training the connection weights of two-stage NNs separately in training phase, the connection weights of the unified NN are updated again in verification phase according to error between the predicted and target gains to eliminate the inherent error of the NNs. The simulation results show that the mean of root mean square error(RMSE) and maximum error of gains are 0.131 d B and 0.281 d B, respectively. It shows that the method can realize adaptive adjustment function of FRA gain with high accuracy.展开更多
At 4 pm,the first cinema in the Taxkorgan Tajik Autonomous County in Kashi Prefecture opened at the appointed time.The manager,He Xinyu,was prepared to welcome local filmgoers from various ethnic groups.Manager He can...At 4 pm,the first cinema in the Taxkorgan Tajik Autonomous County in Kashi Prefecture opened at the appointed time.The manager,He Xinyu,was prepared to welcome local filmgoers from various ethnic groups.Manager He can feel that for local residents,the cinema is more than a venue for entertainment-it is a space for connections and inspiration.“The cinema and these screening films,which screen simultaneously with those in other places,offer local residents a sense of belonging to a larger world and a fresh feeling of appreciating cultural products,which means a lot,”said He.展开更多
Chengdu,a city rich in history and culture,is a beacon of China’s storied past embracing a distinct postmodern vibe.As an important hub along the ancient Silk Road,it has long been a meeting point for di!erent civili...Chengdu,a city rich in history and culture,is a beacon of China’s storied past embracing a distinct postmodern vibe.As an important hub along the ancient Silk Road,it has long been a meeting point for di!erent civilizations,where ideas and cultures have exchanged and thrived.Driven by the vision of a community with a shared future for mankind in recent years,Chengdu scholars and media have opened their arms to the world,engaging in multilingual storytelling.These efforts share the warmth and goodwill of a city consistently ranked one of the happiest in China.Through consistent efforts,new insights have emerged—ideas and aspirations intended to be shared with readers both at home and abroad.展开更多
A prior observational study indicated an asymmetric link between sea surface temperature(SST)in the Tasman Sea and ENSO during austral summer.Specifically,El Niño is associated with a dipolar SST anomaly pattern,...A prior observational study indicated an asymmetric link between sea surface temperature(SST)in the Tasman Sea and ENSO during austral summer.Specifically,El Niño is associated with a dipolar SST anomaly pattern,featuring warming in the northwest and cooling in the southeast,whereas La Niña corresponds to basin-scale warming.This study employs the experiments of coupled models from the sixth phase of the Coupled Model Intercomparison Project(CMIP6)to assess ENSO’s impact on Tasman Sea SST.While all 15 models capture the observed dipolar SST anomalies(SSTAs)in the Tasman Sea during El Niño years,only 7 models capture the basin-scale warmth in the Tasman Sea during La Niña years.Consequently,the models are bifurcated into two groups:group-one models yield one physically reasonable asymmetric connection as observed,including the asymmetry of oceanic heat transport,especially the Ekman meridional transport anomalies induced by zonal wind stress driven by the asymmetric atmospheric circulation over the Tasman Sea.However,due to abnormal responses to ENSO and systematic biases in model simulations,including jet and storm tracks,oceanic heat fluxes,ocean currents,and SST,the group-two models fail to reproduce the asymmetric connection between the Tasman Sea and ENSO.This study not only validates the observational asymmetric connection of SSTAs in the Tasman Sea with respect to the two opposite ENSO phases,but also provides evidence and clues to reduce the bias in group-two models.展开更多
Objectives:The effect of attentional focusing on muscular activities and motor skills has been well established.It is known that internal focusing(on body movement or the action itself)results in increased muscular ac...Objectives:The effect of attentional focusing on muscular activities and motor skills has been well established.It is known that internal focusing(on body movement or the action itself)results in increased muscular activity.However,external focusing(on apparatus or the effect of action)results in decreased motor responses.In this study,the impact of attentional focusing has been investigated by exploring the three major components of hamstrings:the semitendinosus,the semimembranosus and the biceps femoris via EMG activity on 20 amateur football players during leg curl exercises.Methods:To measure muscle activities of the participants,Integrated EMG(IEMG)was calculated on the data’s MVC values.Paired sampled t-tests with Bonferroni correction(α=0.0167)were performed on the average IEMG values to determine if there is a significant difference between participants’muscles activities under various attentional focus conditions.Results:The results showed that the semimembranosus exhibited significantly reduced activity under both external(p=0.0124)and internal focus(p=0.0008),while the semitendinosus displayed a small but non-significant reduction under external focus(p=0.0355>0.0167).The biceps femoris showed no significant motor response regarding change between attentional focus instructions.Conclusions:This study improves understanding of the mind-muscle connection by showing muscle-specific differences in attentional focus effects,with semimembranosus being most responsive.展开更多
基金Natural Science Foundation of China under Grant No.52178449,the Beijing Natural Science Foundation under Grant No.8234060the Innovation Center of Beijing Association for Science and Technology。
文摘This study proposes a new post-tensioned precast bridge column(PT-PBC)with a socket connection.Compared to conventional PBCs connected by PT tendons,the combination of the PT tendons with the socket connection can avoid tensioning the PT tendons on site,which further accelerates construction speed while improving construction quality and safety.In addition,compared to conventional PBCs with a socket connection,a rocking interface can avoid the formation of a plastic hinge in a column,which greatly alleviates seismic damage to that area.One specimen for quasi-static testing is used to validate the feasibility of this connection type.Subsequently,finite element models(FEM)are established to systematically predict the responses of the proposed columns under lateral cyclic loading.The accuracy of the FEM is verified through quasistatic testing.Next,the influences of the key design parameters of the PT-PBC,including the area ratio and prestress level of the PT tendons,the area ratio of energy dissipation(ED)steel rebars,and the total axial compression ratio on the seismic performances of PT-PBC are systematically investigated.The use of shape memory alloy(SMA)rods as energy dissipation devices and their performances also are investigated.The results show that increasing the area ratio and prestress level of PT tendons has an overall positive impact on the self-centering capacity of the column.The prestress level of PT tendons should be kept between 35%and 55%,depending on different conditions.The total compression axial ratio of the columns should be maintained between 0.3 and 0.4.Both ED steel rebars and SMA rods can boost the column’s energy dissipation capacity,while SMA rods can reduce residual deformation due to their inherent mechanical properties.
基金supported by the“Regional Innovation System&Education(RISE)”through the Seoul RISE Center,funded by the Ministry of Education(MOE)and the Seoul Metropolitan Government.(2025-RISE-01-005-07).
文摘Background:Social connection is widely recognized as a protective determinant of health,yet its direct and indirect effects on mental health remain underexplored.This study examines the relationship between social connection and mental health,focusing on the mediating role of quality of life(QoL)and the moderating effect of regional differences.Methods:We analyzed data from the 2019 Korean Community Health Survey,comprising 229,099 adults.Mental health was assessed through validated measures of depressive symptoms and psychological well-being.Social connection was measured using indicators of interpersonal ties and community participation,and QoL was assessed via self-reported health-related satisfaction across major life domains.Analytical procedures included mediation modeling and subgroup analyses by region,with significance levels set at p<0.05.Results:The results indicate that social connections are significantly associated with lower stress levels and reduced depressive symptoms,with QoL playing a critical mediating role.Notably,the indirect effect of social connection on mental health via QoL is stronger in rural areas compared to urban regions,highlighting the importance of social cohesion and community support in mental well-being.Among 203,567 adults,greater social participation was associated with lower subjective stress(total effect=−0.052,p<0.001)and fewer depressive symptoms(PHQ-9 total effect=−0.308,p<0.001).QoL significantly mediated these associations,with the strongest indirect pathways observed through usual activities(19.2%for stress;27.6%for depression)and mobility(24.4%for depression).Regional analysis showed stronger mediation in rural areas(up to 26.8%for stress and 32.6%for depression)than in urban areas(8–16%and 14.9–23%).Direct effects remained significant,indicating partial mediation.These findings highlight that social participation enhances mental health directly and indirectly through QoL,particularly in rural contexts.Conclusions:Social connection contributes to better mental health both directly and indirectly through improved QoL,with stronger effects observed in rural communities.These findings highlight the importance of fostering social cohesion and enhancing life quality as strategies for improving population mental health.Policy interventions should adopt context-sensitive approaches that account for regional differences in social resources and service availability.
基金supported by the Science and Technology Research Project of Henan Province(242102241055)the Industry-University-Research Collaborative Innovation Base on Automobile Lightweight of“Science and Technology Innovation in Central Plains”(2024KCZY315)the Opening Fund of State Key Laboratory of Structural Analysis,Optimization and CAE Software for Industrial Equipment(GZ2024A03-ZZU).
文摘In two-scale topology optimization,enhancing the connectivity between adjacent microstructures is crucial for achieving the collaborative optimization of micro-scale performance and macro-scale manufacturability.This paper proposes a two-scale concurrent topology optimization strategy aimed at improving the interface connection strength.This method employs a parametric approach to explicitly divide the micro-design domain into a“boundary connection region”and a“free design domain”at the initial stage of optimization.The boundary connection region is used to generate a connection layer that enhances the interface strength,while the free design domain is not constrained by this layer,thus fully exploiting the design potential of the material layout.During the optimization process,the solid isotropic material with penalization(SIMP)method is first used to optimize the material distribution in the free design domain,and filtering and projection techniques are employed to alleviate numerical instability and obtain a clear topological structure.Subsequently,the effective performance of the microstructure is calculated through homogenization and transferred to the macro-scale for global response analysis.Throughout the iterative process,the geometry of the connection layer remains unchanged,and only the free design domain is optimized,thereby achieving a balance between high performance and good manufacturability.The effectiveness of the proposed method is verified through numerical examples.
基金supported by High-level Talents Program of Hainan Basic and Applied Basic Research Program of China(520RC543)Crosswise Tasks of Enterprise Entrusted(JG-ZH-A-202411-003).
文摘To achieve efficient connection and integrity in prefabricated frame structures,a novel beam-column connection between prefabricated steel-reinforced concrete(SRC)columns and cast-in-situ reinforced concrete(RC)beams is proposed.Four connection specimens with varying thicknesses of connecting cover plates were designed and fabricated.Low-cycle reversed loading tests were conducted to obtain mechanical performance data,allowing for analysis of behavioral patterns,including load-displacement hysteresis curves,skeleton curves,load-carrying capacity,deformation performance,energy dissipation capacity,and stiffness degradation.Test results indicate that properly designed prefabricated connections exhibit mechanical properties comparable to those of cast-in-situ concrete connections.The hysteresis curves of the prefabricated connections are well-shaped,with nearly no reduction in load-carrying capacity and deformation performance,demonstrating excellent seismic behavior.The findings provide a theoretical basis and reference for the design of prefabricated concrete frame structures.
基金supported by the National Natural Science Foundation of China(62522119 and 62372358)the Beijing Natural Science Foundation(7242267)+2 种基金the Beijing Scholars Program([2015]160)the Natural Science Basic Research Program of Shaanxi(2023-JC-QN-0719)the Guangdong Basic and Applied Basic Research Foundation(2022A1515110453)。
文摘Background:Brain volume measurement serves as a critical approach for assessing brain health status.Considering the close biological connection between the eyes and brain,this study aims to investigate the feasibility of estimating brain volume through retinal fundus imaging integrated with clinical metadata,and to offer a cost-effective approach for assessing brain health.Methods:Based on clinical information,retinal fundus images,and neuroimaging data derived from a multicenter,population-based cohort study,the Kai Luan Study,we proposed a cross-modal correlation representation(CMCR)network to elucidate the intricate co-degenerative relationships between the eyes and brain for 755 subjects.Specifically,individual clinical information,which has been followed up for as long as 12 years,was encoded as a prompt to enhance the accuracy of brain volume estimation.Independent internal validation and external validation were performed to assess the robustness of the proposed model.Root mean square error(RMSE),peak signal-tonoise ratio(PSNR),and structural similarity index measure(SSIM)metrics were employed to quantitatively evaluate the quality of synthetic brain images derived from retinal imaging data.Results:The proposed framework yielded average RMSE,PSNR,and SSIM values of 98.23,35.78 d B,and 0.64,respectively,which significantly outperformed 5 other methods:multi-channel Variational Autoencoder(mcVAE),Pixelto-Pixel(Pixel2pixel),transformer-based U-Net(Trans UNet),multi-scale transformer network(MT-Net),and residual vision transformer(ResViT).The two-(2D)and three-dimensional(3D)visualization results showed that the shape and texture of the synthetic brain images generated by the proposed method most closely resembled those of actual brain images.Thus,the CMCR framework accurately captured the latent structural correlations between the fundus and the brain.The average difference between predicted and actual brain volumes was 61.36 cm~3,with a relative error of 4.54%.When all of the clinical information(including age and sex,daily habits,cardiovascular factors,metabolic factors,and inflammatory factors)was encoded,the difference was decreased to 53.89 cm~3,with a relative error of 3.98%.Based on the synthesized brain magnetic resonance images from retinal fundus images,the volumes of brain tissues could be estimated with high accuracy.Conclusion:This study provides an innovative,accurate,and cost-effective approach to characterize brain health status through readily accessible retinal fundus images.
基金supported by the Guangdong Grant Key Technologies for Treatment of Brain Disorders,China,No.2018B030332001(to GC)the Natural Science Foundation of Guangdong Province,China,No.2023A1515012397(to YX).
文摘Optic nerve injury leads to axonal degeneration and the death of retinal ganglion cells,which ultimately causes vision loss.Notably,current treatments are limited.In the present study,we explored whether neurogenic differentiation factor 1(NeuroD1 or ND1)overexpression in retinal Müller cells may repair the retina after optic nerve crush in mice.Adult mice were subjected to optic nerve crush followed by intravitreal AAV-7m8-GFAP-GFP-ND1 virus injection.Immunofluorescent staining,multi-electrode array recording,electroretinogram,and visual behavior tests were then performed to examine retinal and optic nerve structure and retinal function at various post-optic nerve crush and virus injection times.Western blot analysis and quantitative reverse transcription polymerase chain reaction were performed to explore the possible mechanisms.Compared with the control virus,specific overexpression of ND1 in Müller cells greatly improved the light responses of retinal ganglion cells and retinal neurons in optic nerve crush-injured mice as early as 1-2 weeks post-virus injection and lasted for up to 4 weeks.Neuronal survival in the ganglion cell layer and synaptic connections in the inner retina were slightly improved at 2 weeks;however,visual behavior,retinal ganglion cell survival,and optic nerve structure were not improved.ND1 transiently enhanced glial cell-derived neurotrophic factor expression in the optic nerve crush-injured retina but hardly inhibited retinal inflammation within 2 weeks.Together,our data indicate that ND1 overexpression in Müller cells improves retinal function in the optic nerve crush-injured retina,and suggest that its neuroprotective effect may be caused by enhanced glial cell-derived neurotrophic factor release.
基金supported in part by the National Natural Science Foundation of China under Grant 51877061.
文摘For the ultra HVDC(UHVDC)with the hierarchical connection mode at the inverter side,considering the change of the Thevenin equivalent parameters(TEP)of post-fault AC grid,a coordinated control strategy to the subsequent commutation failure(SCF)at both layers is newly proposed.The originality of this work is manifested in three aspects.1)The mechanism of the SCF at the fault layer is newly found by deriving the analytical expression of the extinction angle with the TEP,and that at the non-fault layer is newly found by the voltage-time area theory with the DC current coupling.2)An estimation model for the TEPs of two AC grids at the inverter side is proposed with the post-fault quantities.To address the random noise and inaccurate measurement data,an adaptive robust least squares method based on the median principle is proposed to solve the TEP model.3)A coordinated control strategy with the estimated TEP is proposed to compensate for the extinction angle at the fault layer and limit the DC current at the non-fault layer,thus suppressing the SCF.The simulation results verify the suppression effect of the proposed control on the SCF under different fault conditions.
基金Project supported by Quantum Science and Technology–National Science and Technology Major Project(Grant No.2024ZD0301000)the National Natural Science Foundation of China(Grant No.12305031)+1 种基金the Hangzhou Joint Fund of the Natural Science Foundation of Zhejiang Province,China(Grant No.LHZSD24A050001)the Science Foundation of Zhejiang Sci-Tech University(Grant Nos.23062088Y and 23062153-Y)。
文摘The Wilczek–Zee connection(WZC)is a key concept in the study of topology of quantum systems.Here,we introduce the double Wilczek–Zee connection(DWZC)which naturally appears in the pure-state quantum geometric tensor(QGT),another important concept in the field of quantum geometry.The DWZC is Hermitian with respect to the two integer indices,just like the original Hermitian WZC.Based on the symmetric logarithmic derivative operator,we propose a mixed-state quantum geometric tensor.Using the symmetric properties of the DWZC,we find that the real part of the QGT is connected to the real part of the DWZC and the square of eigenvalue differences of the density matrix,whereas the imaginary part can be given in terms of the imaginary part of the DWZC and the cube of the eigenvalue differences.For density matrices with full rank or no full rank,the QGT can be given in terms of real and imaginary parts of the DWZC.
文摘Founded in September 2020,the International SparkLink Alliance(iSLA)now has approximately 1,200 members in diverse sectors including terminals,homes,vehicles,manufacturing,transportation,finance and healthcare.The iSLA has established a technical standards system for wireless short-range communication covering full-stack standards such as the end-to-end protocol system.
基金supported by the National Natural Science Foundation of China(51877061).
文摘Preventive maintenance(PM)enhances the reliability of an ultra-high-voltage DC(UHVDC)line.However,it introduces new states and complicates the task of determining the reliability parameters of the component with PM.The hierarchical connection(HC)of the inverter improves the flexibility of UHVDC,but the state spaces of the inverter and UHVDC-HC are determined by capacity distribution between the high terminal(HT)and low terminal(LT),which has not been studied yet.In this paper,the reliability of UHVDC-HC with the PM is studied.First,with the impact of PM described by a nonlinear coefficient,the state space of the components with PM is aggregated.It is the same size as without PM.The only difference is the transition rate.Second,considering power distribution between the HT/LT and its dependence on the state of the rectifier,new capacity levels of HT/LT,e.g.,75%/2,50%/3,are defined.Third,with capacity levels of the HT/LT differentiated,2 existing reliability indices are extended,and 2 are newly defined.Finally,a sensitivity model of the reliability of the UHVDC-HC to its parameters and the PM period is proposed.
基金supported by Science and Technology Projects of Jiangsu Province(No.BE2022003)Science and Technology Projects of Jiangsu Province(No.BE2022003-5).
文摘To improve the fault diagnosis accuracy of a PV grid-connected inverter,a PV grid-connected inverter data diagnosis method based on MPA-VMD-PSO-BiLSTM is proposed.Firstly,unlike the traditional VMD algorithm which relies on manual experience to set parameters(e.g.,noise tolerance,penalty parameter,number of decompositions),this paper achieves adaptive optimization of parameters through MPA algorithmto avoid the problemof feature information loss caused by manual parameter tuning,and adopts the improved VMD algorithm for feature extraction of DC-side voltage data signals of PV-grid-connected inverters;and then,adopts the PSO algorithm for theThen,the PSO algorithm is used to optimize the optimal batch size,the number of nodes in the hidden layer and the learning rate of the BiLSTM network,which significantly improves the model’s ability to capture the long-term dependent features of the PV inverter’s timing signals,to construct the PV grid-connected inverter prediction model of PSO-BiLSTM,and predict the capacitance value of the PVgrid-connected inverter.Finally,diagnostic experiments are carried out based on the expected capacitance value and the capacitance failure criterion.The results showthat compared with the traditional VMD algorithm,the MPA-optimised VMD improves the signal-to-noise ratio(SNR)of the signal decomposition from 28.5 to 33.2 dB(16.5%improvement).After combining with the PSO-BiLSTM model,the mean absolute percentage error(MAPE)of the fault diagnosis is reduced to 1.31%,and the coefficient of determination(R2)is up to 0.99.It is concluded that the present method has excellent diagnostic performance of PV grid-connected inverter data signals and effectively improves the accuracy of PV grid-connected inverter diagnosis.
基金supported by the National Natural Science Foundation of China(Nos.52325001 and 52170009)the National Key Research and Development Program of China(No.2021YFC3200700)the Programof Shanghai Academic Research Leader,China(No.21XD1424000).
文摘Emerging contaminants(ECs)have raised global concern due to their adverse effect on ecosystems and human health.However,the occurrence and transport of ECs in stormwater remain unclear.The impact of ECs from stormwater on surface water quality and ecosystem health is also poorly documented.In this review,we examined the variations in EC concentrations in surface water resulting from stormwater.During the wet weather,the concentrations of most investigated ECs,e.g.,microplastics,per-and polyfluoroalkyl substances,and vehicle-related compounds,significantly increase in surface water,indicating that stormwater may be a critical source of these contaminants.Furthermore,the potential pathways of ECs from stormwater enter surface water are outlined.Studies demonstrate that surface runoff and combined sewer overflows are important pathways for ECs,with discharges comparable to or exceeding those from wastewater treatment plants.Illicit connection also plays an important part in elevated EC concentrations in surface water.Overall,our findings underscore the importance of stormwater as a source for ECs in surface waters,and urge for increased emphasis on,and reinforcement of,stormwater monitoring and control measures to minimize the transport of ECs into receiving water bodies.
基金supported by the National Key R&D Program of China (Grant No.2022YFF0503700)the special funds of Hubei Luojia Laboratory (Grant No.220100011)+1 种基金supported by the International Space Science Institute–Beijing(ISSI-BJ) project“The Electromagnetic Data Validation and Scientific Application Research based on CSES Satellite”and ISSI/ISSI-BJ project,“Multi-Scale Magnetosphere–Ionosphere–Thermosphere Interaction.”
文摘The Michelson Interferometer for Global High-resolution Thermospheric Imaging(MIGHTI)onboard the Ionospheric Connection Explorer(ICON)satellite offers the opportunity to investigate the altitude profile of thermospheric winds.In this study,we used the red-line measurements of MIGHTI to compare with the results estimated by Horizontal Wind Model 14(HWM14).The data selected included both the geomagnetic quiet period(December 2019 to August 2022)and the geomagnetic storm on August 26-28,2021.During the geomagnetic quiet period,the estimations of neutral winds from HWM14 showed relatively good agreement with the observations from ICON.According to the ICON observations,near the equator,zonal winds reverse from westward to eastward at around 06:00 local time(LT)at higher altitudes,and the stronger westward winds appear at later LTs at lower altitudes.At around 16:00 LT,eastward winds at 300 km reverse to westward,and vertical gradients of zonal winds similar to those at sunrise hours can be observed.In the middle latitudes,zonal winds reverse about 2-4 h earlier.Meridional winds vary more significantly than zonal winds with seasonal and latitudinal variations.According to the ICON observations,in the northern low latitudes,vertical reversals of meridional winds are found at 08:00-13:00 LT from 300 to 160 km and at around 18:00 LT from 300 to 200 km during the June solstice.Similar reversals of meridional winds are found at 04:00-07:00 LT from 300 to 160 km and at 22:00-02:00 LT from 270 to 200 km during the December solstice.In the southern low latitudes,meridional wind reversals occur at 08:00-11:00 LT from 200 to 160 km and at 21:00-02:00 LT from 300 to 200 km during the June solstice.During the December solstice,reversals of the meridional wind appear at 20:00-01:00 LT below 200 km and at 06:00-11:00 LT from 300 to 160 km.In the northern middle latitudes,the northward winds are dominant at 08:00-14:00 LT at 230 km during the June solstice.Northward winds persist until 16:00 LT at 160 and 300 km.During the December solstice,the northward winds are dominant from 06:00 to 21:00 LT.The vertical variations in neutral winds during the geomagnetic storm on August 26-28 were analyzed in detail.Both meridional and zonal winds during the active geomagnetic period observed by ICON show distinguishable vertical shear structures at different stages of the storm.On the dayside,during the main phase,the peak velocities of westward winds extend from a higher altitude to a lower altitude,whereas during the recovery phase,the peak velocities of the westward winds extend from lower altitudes to higher altitudes.The velocities of the southward winds are stronger at lower altitudes during the storm.These vertical structures of horizontal winds during the storm could not be reproduced by the HWM14 wind estimations,and the overall response to the storm of the horizontal winds in the low and middle latitudes is underestimated by HWM14.The ICON observations provide a good dataset for improving the HWM wind estimations in the middle and upper atmosphere,especially the vertical variations.
基金supported by Prevention the Fundamental Research Funds for the Central Universities“Study on the general joint of prefabricated high-pier columns”(ZY20230218)Science and Technology Innovation Program for Postgraduate students in IDP subsidized by Fundamental Research Funds for the Central Universities“Research on seismic performance of prefabricated bridge piers with embedded separated steel connections”(ZY20250316).
文摘With the acceleration of urbanization,prefabricated bridges have become a significant choice for transportation infrastructure construction due to their environmental friendliness,efficiency,and reliable quality.However,existing connection technologies still face shortcomings in construction efficiency,seismic performance,and cost control.This paper summarizes the process characteristics of commonly used connection technologies such as socket connections,grouted sleeve connections and corrugated pipe connections,and analyzes their seismic capacity and mechanical performance.In response to existing issues,two new technologies—separated steel connection and multi-chamber steel tube concrete connection—are proposed,and their comprehensive performance and economic efficiency are analyzed.The new connection technologies outperform traditional methods in construction efficiency,economic efficiency,and structural stability,with more reasonable force distribution,clearer load transfer paths,and significantly reduced overall costs.Existing technologies,such as socket connections,perform well in seismic performance but are complex to construct;grouted sleeve connections are mature in technology,but the quality of grouting is difficult to inspect.The separated steel connection and multi-chamber steel tube concrete connection technologies offer significant advantages.With the increasing demands for energy conservation and emission reduction,coupled with the rising labor costs,prefabricated bridge piers are undoubtedly poised to become one of the preferred technologies for bridge construction in China in the future.Therefore,in light of the current research landscape,this paper concludes by offering a forward-looking perspective on the development directions of connection methods for prefabricated bridge piers and identifying key areas for future research.
基金supported by the Natural Science Research Project of Colleges and Universities in Anhui Province (No.KJ2021A0479)the Science Research Program of Anhui University of Finance and Economics (No.ACKYC22082)。
文摘We present a gain adaptive tuning method for fiber Raman amplifier(FRA) using two-stage neural networks(NNs) and double weights updates. After training the connection weights of two-stage NNs separately in training phase, the connection weights of the unified NN are updated again in verification phase according to error between the predicted and target gains to eliminate the inherent error of the NNs. The simulation results show that the mean of root mean square error(RMSE) and maximum error of gains are 0.131 d B and 0.281 d B, respectively. It shows that the method can realize adaptive adjustment function of FRA gain with high accuracy.
文摘At 4 pm,the first cinema in the Taxkorgan Tajik Autonomous County in Kashi Prefecture opened at the appointed time.The manager,He Xinyu,was prepared to welcome local filmgoers from various ethnic groups.Manager He can feel that for local residents,the cinema is more than a venue for entertainment-it is a space for connections and inspiration.“The cinema and these screening films,which screen simultaneously with those in other places,offer local residents a sense of belonging to a larger world and a fresh feeling of appreciating cultural products,which means a lot,”said He.
文摘Chengdu,a city rich in history and culture,is a beacon of China’s storied past embracing a distinct postmodern vibe.As an important hub along the ancient Silk Road,it has long been a meeting point for di!erent civilizations,where ideas and cultures have exchanged and thrived.Driven by the vision of a community with a shared future for mankind in recent years,Chengdu scholars and media have opened their arms to the world,engaging in multilingual storytelling.These efforts share the warmth and goodwill of a city consistently ranked one of the happiest in China.Through consistent efforts,new insights have emerged—ideas and aspirations intended to be shared with readers both at home and abroad.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF0805101)the National Natural Science Founda-tion of China(Grant Nos.42376250 and 42405068).
文摘A prior observational study indicated an asymmetric link between sea surface temperature(SST)in the Tasman Sea and ENSO during austral summer.Specifically,El Niño is associated with a dipolar SST anomaly pattern,featuring warming in the northwest and cooling in the southeast,whereas La Niña corresponds to basin-scale warming.This study employs the experiments of coupled models from the sixth phase of the Coupled Model Intercomparison Project(CMIP6)to assess ENSO’s impact on Tasman Sea SST.While all 15 models capture the observed dipolar SST anomalies(SSTAs)in the Tasman Sea during El Niño years,only 7 models capture the basin-scale warmth in the Tasman Sea during La Niña years.Consequently,the models are bifurcated into two groups:group-one models yield one physically reasonable asymmetric connection as observed,including the asymmetry of oceanic heat transport,especially the Ekman meridional transport anomalies induced by zonal wind stress driven by the asymmetric atmospheric circulation over the Tasman Sea.However,due to abnormal responses to ENSO and systematic biases in model simulations,including jet and storm tracks,oceanic heat fluxes,ocean currents,and SST,the group-two models fail to reproduce the asymmetric connection between the Tasman Sea and ENSO.This study not only validates the observational asymmetric connection of SSTAs in the Tasman Sea with respect to the two opposite ENSO phases,but also provides evidence and clues to reduce the bias in group-two models.
文摘Objectives:The effect of attentional focusing on muscular activities and motor skills has been well established.It is known that internal focusing(on body movement or the action itself)results in increased muscular activity.However,external focusing(on apparatus or the effect of action)results in decreased motor responses.In this study,the impact of attentional focusing has been investigated by exploring the three major components of hamstrings:the semitendinosus,the semimembranosus and the biceps femoris via EMG activity on 20 amateur football players during leg curl exercises.Methods:To measure muscle activities of the participants,Integrated EMG(IEMG)was calculated on the data’s MVC values.Paired sampled t-tests with Bonferroni correction(α=0.0167)were performed on the average IEMG values to determine if there is a significant difference between participants’muscles activities under various attentional focus conditions.Results:The results showed that the semimembranosus exhibited significantly reduced activity under both external(p=0.0124)and internal focus(p=0.0008),while the semitendinosus displayed a small but non-significant reduction under external focus(p=0.0355>0.0167).The biceps femoris showed no significant motor response regarding change between attentional focus instructions.Conclusions:This study improves understanding of the mind-muscle connection by showing muscle-specific differences in attentional focus effects,with semimembranosus being most responsive.
