Glasses are known to possess low-frequency excess modes beyond the Debye prediction.For decades,it has been assumed that evolution of low-frequency density of excess modes D(ω) with frequency ω follows a power-law s...Glasses are known to possess low-frequency excess modes beyond the Debye prediction.For decades,it has been assumed that evolution of low-frequency density of excess modes D(ω) with frequency ω follows a power-law scaling:D(ω)~ω~γ.However,it remains debated on the value of γ at low frequencies below the first phonon-like mode in finitesize glasses.Early simulation studies reported γ=4 at low frequencies in two-(2D),three-(3D),and four-dimensional(4D)glasses,whereas recent observations in 2D and 3D glasses suggested γ=3.5 in a lower-frequency regime.It is uncertain whether the low-frequency scaling of D(ω)~ω^(3.5) could be generalized to 4D glasses.Here,we conduct numerical simulation studies of excess modes at frequencies below the first phonon-like mode in 4D model glasses.It is found that the system size dependence of D(ω) below the first phonon-like mode varies with spatial dimensions:D(ω) increases in2D glasses but decreases in 3D and 4D glasses as the system size increases.Furthermore,we demonstrate that the ω^(3.5)scaling,rather than the ω~4 scaling,works in the lowest-frequency regime accessed in 4D glasses,regardless of interaction potentials and system sizes examined.Therefore,our findings in 4D glasses,combined with previous results in 2D and 3D glasses,suggest a common low-frequency scaling of D(ω)~ ω^3.5) below the first phonon-like mode across different spatial dimensions,which would inspire further theoretical studies.展开更多
BACKGROUND Patients with knee arthroplasty often have problems such as slow recovery of knee function,which may cause negative emotions and affect their postoperative rehabilitation.The application of sensory and moto...BACKGROUND Patients with knee arthroplasty often have problems such as slow recovery of knee function,which may cause negative emotions and affect their postoperative rehabilitation.The application of sensory and motor training in the Acknowledge,Introduce,Duration,Evaluation,Thank You(AIDET)communication mode in patients after knee arthroplasty can provide reference for the selection of postoperative rehabilitation training measures.AIM To explore the sensory and motor training effects in AIDET communication mode on knee function recovery and resilience of patients after knee arthroplasty.METHODS One hundred patients who underwent knee arthroplasty at our hospital between January 2022 and January 2024 were randomly divided into two groups.The control group(n=50)received routine rehabilitation training.In the observation group(n=50),the AIDET communication mode was used to perform sensory and motor training,in addition to routine rehabilitation training.The rehabilitation training was administered for 8 weeks.After surgery,knee function,balance ability,walking ability,proprioception,and resilience were compared between the two groups.RESULTS The New York Hospital for Special Surgery knee scores of the observation group at the time of discharge and 8 weeks after intervention were(65.23±6.84,84.53±5.27),which was higher than those of the control group(61.03±7.15,74.92±6.52)(P<0.05).The balance ability of the observation group at the time of discharge and 8 weeks after the intervention was higher than that of the control group,the time of time up to go test was shorter than that of the control group,and proprioceptive function was higher than that of the control group(P<0.05).The resilience level in the observation group after the intervention was higher than that in the control group(P<0.05).CONCLUSION Sensory and motor training in AIDET communication mode promotes knee function recovery of patients after knee arthroplasty,improves their limb walking ability and balance function,and increases their resilience level.展开更多
The concept of“STEM+”integrates art,humanistic literacy,and social values in the traditional STEM education concept,advocates cross-disciplinary integration,and aims to cultivate compound talents equipped to tackle ...The concept of“STEM+”integrates art,humanistic literacy,and social values in the traditional STEM education concept,advocates cross-disciplinary integration,and aims to cultivate compound talents equipped to tackle future challenges.In 2022,the Ministry of Education issued the“Compulsory Education Information Technology Curriculum(2022 Edition),”emphasizing the core literacy of information science and technology and the integration of interdisciplinary disciplines,and encouraging the teaching mode suitable for discipline characteristics.The 6E teaching mode is a student-centered teaching strategy characterized by active exploration and cross-disciplinary integration.This article innovatively designed the“STEM+”6E teaching mode,which is applied to junior high school information technology teaching,which can better achieve core literacy teaching goals.展开更多
Objective:To analyze the value of using virtual reality combined with the flipped classroom teaching model in teaching cardiopulmonary resuscitation(CPR).Methods:Two classes of our nursing program were randomly select...Objective:To analyze the value of using virtual reality combined with the flipped classroom teaching model in teaching cardiopulmonary resuscitation(CPR).Methods:Two classes of our nursing program were randomly selected for the study from September 2022 to September 2023,Class A(52 students,conventional teaching method)and Class B(52 students,virtual reality combined with flipped classroom teaching mode).The assessment scores and independent learning ability scores of the students in the two classes were compared.Results:CPR theory and operation scores,passing rate,and independent learning ability scores of Class B were higher than those of Class A(P<0.05).Conclusion:the use of virtual reality combined with the flipped classroom teaching mode in CPR teaching is conducive to the improvement of students’assessment scores and independent learning ability.展开更多
Bamboo is an eco-friendly material with light weight,high strength,short growth cycle and high sustainability,which is widely used in building structures.Engineered bamboo has further promoted the development of moder...Bamboo is an eco-friendly material with light weight,high strength,short growth cycle and high sustainability,which is widely used in building structures.Engineered bamboo has further promoted the development of modern bamboo structures due to its unrestricted size and shape.However,as a fiber-reinforced material,fracture damage,especially Mode I fracture damage,becomes the most likely damage mode of its structure,so Mode I fracture characteristics are an important subject in the research of mechanical properties of bamboo.This paper summarizes the current status of experimental research on the Mode I fracture properties of bamboo based on the three-point bending(TPB)method,the single-edge notched beam(SENB)method,the compact tension(CT)method and the double cantilever beam(DCB)method,compares the fracture toughness of different species of bamboo,analyzes the toughening mechanisms and fracture damage modes,discusses the applicability of different theoretical calculation methods,and makes suggestions for future research priorities,aiming to provide a reference for future research and engineering applications in related fields.展开更多
A quasi-coherent(QC)mode was observed in the core region of low-density ohmic plasmas in Sino-UNIted Spherical Tokamak.In experiments on the QC mode,two sets of moveable Langmuir probes(LPs)were used to measure the lo...A quasi-coherent(QC)mode was observed in the core region of low-density ohmic plasmas in Sino-UNIted Spherical Tokamak.In experiments on the QC mode,two sets of moveable Langmuir probes(LPs)were used to measure the local parameters including floating potential,electron temperature,electron density,and so on,as well as their profiles.To monitor the magnetohydrodynamic activities,a Mirnov probe was used to measure the poloidal magnetic fluctuation.The QC mode can be seen in the spectra of floating potential,but there is no similar peak in the spectra of magnetic fluctuation.Thus,the QC mode is probably electrostatic.By analyzing the electrostatic potential fluctuations from the LPs,the features of the QC mode including frequency,wavenumber,propagation direction,and dependence on collisionality are identified,which are consistent with the characteristics of dissipative trapped electron mode.展开更多
The linear behavior of the dominant unstable mode(m=2,n=1)and its high order harmonics(m=2n,n≥2)are numerically investigated in a reversed magnetic shear cylindrical plasma with two q=2 rational surfaces on the basis...The linear behavior of the dominant unstable mode(m=2,n=1)and its high order harmonics(m=2n,n≥2)are numerically investigated in a reversed magnetic shear cylindrical plasma with two q=2 rational surfaces on the basis of the non-reduced magnetohydrodynamics(MHD)equations.The results show that with low beta(beta is defined as the ratio of plasma pressure to magnetic field pressure),the dominant mode is a classical double tearing mode(DTM).However,when the beta is sufficiently large,the mode is driven mainly by plasma pressure.In such a case,both the linear growth rate and mode structures are strongly affected by pressure,while almost independent of the resistivity.This means that the dominant mode undergoes a transition from DTM to pressure-driven mode with the increase of pressure,which is consistent with the experimental result in ASDEX Upgrade.The simulations also show that the distance between two rational surfaces has an important influence on the pressure needed in mode transition.The larger the distance between two rational surfaces,the larger the pressure for driving the mode transition is.Motivated by the phenomena that the high-m modes may dominate over low-m modes at small inter-resonance distance,the high-m modes with different pressures and q profiles are studied too.展开更多
The high-density,vertically aligned retinal neuron array provides effective vision,a feature we aim to replicate with electronic devices.However,the conventional complementary metal-oxide-semiconductor(CMOS)image sens...The high-density,vertically aligned retinal neuron array provides effective vision,a feature we aim to replicate with electronic devices.However,the conventional complementary metal-oxide-semiconductor(CMOS)image sensor,based on separate designs for sensing,memory,and processing units,limits its integration density.Moreover,redundant signal communication significantly increases energy consumption.Current neuromorphic devices integrating sensing and signal processing show promise in various computer vision applications,but there is still a need for frame-based imaging with good compatibility.In this study,we developed a dual-mode image sensor based on a high-density all-inorganic perovskite nanowire array.The device can switch between frame-based standard imaging mode and neuromorphic imaging mode by applying different biases.This unique bias-dependent photo response is based on a well-designed energy band diagram.The biomimetic alignment of nanowires ensures the potential for high-resolution imaging.To further demonstrate the imaging ability,we conducted pattern reconstruction in both modes with a 10×10 crossbar device.This study introduces a novel image sensor with high compatibility and efficiency,suitable for various applications including computer vision,surveillance,and robotics.展开更多
Both current and pressure coupling schemes have been adopted in the hybrid kinetic–magnetohydrodynamic code CLT-K recently.Numerical equivalences between these two coupling schemes are strictly verified under differe...Both current and pressure coupling schemes have been adopted in the hybrid kinetic–magnetohydrodynamic code CLT-K recently.Numerical equivalences between these two coupling schemes are strictly verified under different approximations.First,when considering only the perturbed distribution function of energetic particles(EPs),the equivalence can be proved analytically.Second,when both the variations of the magnetic field and the EP distribution function are included,the current and pressure coupling schemes numerically produce the same result in the nonlinear simulations.On this basis,the influences of co-/counter-passing and trapped EPs on the linear stabilities of the m/n=2/1 tearing mode(TM)have been investigated(where m and n represent the poloidal and toroidal mode numbers,respectively).The results of scanningβh of EPs show that the co-passing and trapped EPs are found to stabilize the TM,while the counter-passing EPs tend to destabilize the TM.The behind(de)stabilization mechanisms of the TM by EPs are carefully analyzed.Furthermore,after exceeding critical EP betas,the same branch of the high-frequency mode is excited by co-/counterpassing and trapped EPs,which is identified as the m/n=2/1 energetic particle mode.展开更多
Modern apprenticeship is a talent cultivation mode of deep integration between schools and enterprises,and an effective way for higher vocational colleges and universities to improve the quality of talent cultivation ...Modern apprenticeship is a talent cultivation mode of deep integration between schools and enterprises,and an effective way for higher vocational colleges and universities to improve the quality of talent cultivation and realize professional service to society.Guangxi College for Preschool Education of Special Education College of Applied Behavior Analysis cooperates with Guangxi Youzhuan Special Children Care Service Center to coeducate rehabilitation teachers of autistic children using the modern apprenticeship mode,constructs school-enterprise synergistic cultivation mechanism,promotes the integration of enrollment and recruitment,improves the system and standard of talent cultivation,builds the faculty team that is mutually employed by the school and enterprise,establishes the guarantee for the management system of modern apprenticeship,and so on.The practice has been carried out with the initial experience gained.However,the construction of a long-term operation mechanism of the modern apprenticeship mode still requires consideration of the contradiction with the traditional cultivation mode and the construction of a perfect evaluation system.展开更多
A detailed analysis of mode II stress intensity factors(SIFs) for the double edge cracked Brazilian disk subjected to different diametral compression is presented using a weight function method. The mode II SIFs at cr...A detailed analysis of mode II stress intensity factors(SIFs) for the double edge cracked Brazilian disk subjected to different diametral compression is presented using a weight function method. The mode II SIFs at crack tips can be obtained by simply calculating an integral of the product of mode II weight function and the shear stress on the prospective crack faces of uncracked disk loaded by a diametral compression. A semi-analytical formula for the calculation of normalized mode II SIF, f _Ⅱ, is derived for different crack lengths (from 0.1 to 0.7) and inclination angles (from 10° to 75°) with respect to loading direction. Comparison between the obtained results and finite element method solutions shows that the weight function method is of high precision. Combined with the authors previous work on mode I fracture analysis, the new specimen geometry can be used to study fracture through any combination of mode I and mode II loading by a simple alignment of the crack relative to the diameter of compression loading, and to obtain pure mode II crack extension. Another advantage of this specimen geometry is that it is available directly from rock core and is also easy to fabricate.展开更多
Prediction of mode I fracture toughness(KIC) of rock is of significant importance in rock engineering analyses. In this study, linear multiple regression(LMR) and gene expression programming(GEP)methods were used to p...Prediction of mode I fracture toughness(KIC) of rock is of significant importance in rock engineering analyses. In this study, linear multiple regression(LMR) and gene expression programming(GEP)methods were used to provide a reliable relationship to determine mode I fracture toughness of rock. The presented model was developed based on 60 datasets taken from the previous literature. To predict fracture parameters, three mechanical parameters of rock mass including uniaxial compressive strength(UCS), Brazilian tensile strength(BTS), and elastic modulus(E) have been selected as the input parameters. A cluster of data was collected and divided into two random groups of training and testing datasets.Then, different statistical linear and artificial intelligence based nonlinear analyses were conducted on the training data to provide a reliable prediction model of KIC. These two predictive methods were then evaluated based on the testing data. To evaluate the efficiency of the proposed models for predicting the mode I fracture toughness of rock, various statistical indices including coefficient of determination(R2),root mean square error(RMSE), and mean absolute error(MAE) were utilized herein. In the case of testing datasets, the values of R2, RMSE, and MAE for the GEP model were 0.87, 0.188, and 0.156,respectively, while they were 0.74, 0.473, and 0.223, respectively, for the LMR model. The results indicated that the selected GEP model delivered superior performance with a higher R2value and lower errors.展开更多
The instability of the Mack mode is destabilized by wall-cooling in a high speed boundary layer. The aim of this paper is to study the mechanism of the wall cooling effect on the Mack mode instability by numerical met...The instability of the Mack mode is destabilized by wall-cooling in a high speed boundary layer. The aim of this paper is to study the mechanism of the wall cooling effect on the Mack mode instability by numerical methods. It is shown that the wall-cooling can destabilize the Mack mode instability, similar to the previous conclusions with the exception that the Mack mode instability can be stabilized by wall-cooling if the wall temperature is extremely low. The reversed wall temperature is related to a freestream condition. If the Mach number increases to a large enough value, e.g., about 7, the reversed wall temperature will tend to be zero. It seems that the Mack mode instability is determined by the region between the boundary layer edge and the critical layer. When the wall temperature decreases, this region becomes wider, and the boundary layer becomes more unstable. Additionally, a relative supersonic unstable mode can be observed when the velocity of the critical layer is less than 1 - liMa or is cancelled by the wall-cooling effect. These results provide a deeper understanding on the wall-cooling effect in high speed boundary layers.展开更多
Two-mode converters at 1.3μm, aiming at applications in mode-division multiplexing in Ethernet systems, are proposed and experimentally demonstrated. Based on multimode interference couplers, the two-mode converters ...Two-mode converters at 1.3μm, aiming at applications in mode-division multiplexing in Ethernet systems, are proposed and experimentally demonstrated. Based on multimode interference couplers, the two-mode converters with 50% and 66% mode conversion efficiencies are designed and fabricated on InP substrates. AIode conver- sion from the fundamental mode (TEo) to the first order mode (TE1) is successfully demonstrated within the wavelength range of 1280-1320nm. The 1.3-μm mode converters should be important devices in mode-division multiplexing systems in Ethernet systems.展开更多
Nonlinear interactions of the two-dimensional (2D) second mode with oblique modes are studied numerically in a Mach 6.0 fiat-plate boundary layer, focusing on its selective enhancement effect on amplification of dif...Nonlinear interactions of the two-dimensional (2D) second mode with oblique modes are studied numerically in a Mach 6.0 fiat-plate boundary layer, focusing on its selective enhancement effect on amplification of different oblique waves. Evolution of oblique modes with various frequencies and spanwise wavenumbers in the presence of 2D second mode is simulated successively, using a modified parabolized stability equation (PSE) method, which is able to simulate interaction of two modes with different frequen- cies efficiently. Numerical results show that oblique modes in a broad band of frequencies and spanwise wavenumbers can be enhanced by the finite amplitude 2D second mode instability wave. The enhancement effect is accomplished by interaction of the 2D second mode, the oblique mode, and a forced mode with difference frequency. Two types of oblique modes are found to be more amplified, i.e., oblique modes with frequency close to that of the 2D second mode and low-frequency first mode oblique waves. Each of them may correspond to one type of transition routes found in transition experiments. The spanwise wavenumber of the oblique wave preferred by the nonlinear interaction is also determined by numerical simulations.展开更多
VLF (very low frequency) mode instability with parallel AC electric field was studied for generalized loss-cone distribution with an index j, which is reducible to bi-Maxwellian, loss- cone and delta function for j ...VLF (very low frequency) mode instability with parallel AC electric field was studied for generalized loss-cone distribution with an index j, which is reducible to bi-Maxwellian, loss- cone and delta function for j = 0, 1 and co. The particle trajectories and dispersion relation are obtained through a kinetic approach and method of characteristic solutions. The calculations are compared with the observations of low frequency waves of Voyager 2. The growth rate of plasma parameters suited to magnetosphere of Uranus is obtained. It is inferred that the magnitude as well as frequency of AC (alternating current) field increases the growth rate and widen the band width significantly. In addition to temperature anisotropy, particles in plasma having generalized loss-cone distribution provide an additional source of energy.展开更多
The paper had analyzed connotation of green agriculture,and pointed out that developing green agriculture is the need to realize socialist new rural construction,the important guarantee for people's consumption sa...The paper had analyzed connotation of green agriculture,and pointed out that developing green agriculture is the need to realize socialist new rural construction,the important guarantee for people's consumption safety and life quality improvement,and the realistic requirement of improvement of agricultural competitiveness.Developing green agriculture could promote strategic adjustment of agricultural structure,and accelerate agricultural industrialization.After analysis of green agriculture development in Langfang City,it pointed out that the development results consisted in that green agricultural base and mode began to take shape,agricultural products' quality supervision and detection system had gradually become perfect and rural environment initially improved.Meanwhile,problems existing in green agricultural development of Langfang City were analyzed,which were unclear understanding of connotation of green agriculture,insufficient support from government and lack of capital investment,imperfect green agricultural production and supporting technology,late development of green agricultural products' market and incomplete marketing network and market system.Through study on current green agricultural development mode of Langfang City,it was hoped to provide reference for further study.展开更多
OBE theory focuses on students’learning outcomes and application ability,which is consistent with the requirements of the new curriculum standard.The paper attempts to apply OBE theory to innovate the construction of...OBE theory focuses on students’learning outcomes and application ability,which is consistent with the requirements of the new curriculum standard.The paper attempts to apply OBE theory to innovate the construction of English classroom teaching mode in senior high schools from aspects of teaching aims,teaching activities,teaching assessments and application activities.Results show that the application of OBE in high schools is beneficial to the development of English teaching and students'learning.展开更多
The identification result of operational mode is eurychoric while operational mode identification is investigated under ambient excitation,which is influenced by the signal size and the time interval.The operational m...The identification result of operational mode is eurychoric while operational mode identification is investigated under ambient excitation,which is influenced by the signal size and the time interval.The operational mode identification method,which is based on the sliding time window method and the eigensystem realization algorithm(ERA),is investigated to improve the identification accuracy and stability.Firstly,the theory of the ERA method is introduced.Secondly,the strategy for decomposition and implementation is put forward,including the sliding time window method and the filtration method of modes.At last,an example is studied,where the model of a cantilever beam is built and the white noise exciting is input.Results show that the operational mode identification method can realize the modes,and has high robustness to the signal to noise ratio and signal size.展开更多
By simulating edge dislocation emissions from a mode I crack tip along multiple inclined slip planes, the plastic zone and dislocation-free zone around the crack tip are obtained. It is found that the shape of the mod...By simulating edge dislocation emissions from a mode I crack tip along multiple inclined slip planes, the plastic zone and dislocation-free zone around the crack tip are obtained. It is found that the shape of the mode I plastic zone consists of two leaning forward loops which is better agreement with experimental observations. Except at the crack tip there are also stress peaks in front of the crack tip. A formula of the maximum peak stress as a function of the applied stress intensity factor and the friction stress has been regressed.展开更多
基金the support from the National Natural Science Foundation of China(Grant Nos.12374202 and 12004001)Anhui Projects(Grant Nos.2022AH020009,S020218016,and Z010118169)Hefei City(Grant No.Z020132009)。
文摘Glasses are known to possess low-frequency excess modes beyond the Debye prediction.For decades,it has been assumed that evolution of low-frequency density of excess modes D(ω) with frequency ω follows a power-law scaling:D(ω)~ω~γ.However,it remains debated on the value of γ at low frequencies below the first phonon-like mode in finitesize glasses.Early simulation studies reported γ=4 at low frequencies in two-(2D),three-(3D),and four-dimensional(4D)glasses,whereas recent observations in 2D and 3D glasses suggested γ=3.5 in a lower-frequency regime.It is uncertain whether the low-frequency scaling of D(ω)~ω^(3.5) could be generalized to 4D glasses.Here,we conduct numerical simulation studies of excess modes at frequencies below the first phonon-like mode in 4D model glasses.It is found that the system size dependence of D(ω) below the first phonon-like mode varies with spatial dimensions:D(ω) increases in2D glasses but decreases in 3D and 4D glasses as the system size increases.Furthermore,we demonstrate that the ω^(3.5)scaling,rather than the ω~4 scaling,works in the lowest-frequency regime accessed in 4D glasses,regardless of interaction potentials and system sizes examined.Therefore,our findings in 4D glasses,combined with previous results in 2D and 3D glasses,suggest a common low-frequency scaling of D(ω)~ ω^3.5) below the first phonon-like mode across different spatial dimensions,which would inspire further theoretical studies.
文摘BACKGROUND Patients with knee arthroplasty often have problems such as slow recovery of knee function,which may cause negative emotions and affect their postoperative rehabilitation.The application of sensory and motor training in the Acknowledge,Introduce,Duration,Evaluation,Thank You(AIDET)communication mode in patients after knee arthroplasty can provide reference for the selection of postoperative rehabilitation training measures.AIM To explore the sensory and motor training effects in AIDET communication mode on knee function recovery and resilience of patients after knee arthroplasty.METHODS One hundred patients who underwent knee arthroplasty at our hospital between January 2022 and January 2024 were randomly divided into two groups.The control group(n=50)received routine rehabilitation training.In the observation group(n=50),the AIDET communication mode was used to perform sensory and motor training,in addition to routine rehabilitation training.The rehabilitation training was administered for 8 weeks.After surgery,knee function,balance ability,walking ability,proprioception,and resilience were compared between the two groups.RESULTS The New York Hospital for Special Surgery knee scores of the observation group at the time of discharge and 8 weeks after intervention were(65.23±6.84,84.53±5.27),which was higher than those of the control group(61.03±7.15,74.92±6.52)(P<0.05).The balance ability of the observation group at the time of discharge and 8 weeks after the intervention was higher than that of the control group,the time of time up to go test was shorter than that of the control group,and proprioceptive function was higher than that of the control group(P<0.05).The resilience level in the observation group after the intervention was higher than that in the control group(P<0.05).CONCLUSION Sensory and motor training in AIDET communication mode promotes knee function recovery of patients after knee arthroplasty,improves their limb walking ability and balance function,and increases their resilience level.
基金2024 Chongqing Normal University Graduate Research Innovation Project“Construction and Application of Information Technology Knowledge Map based on the Three-Layer Architecture”(CYS240395)。
文摘The concept of“STEM+”integrates art,humanistic literacy,and social values in the traditional STEM education concept,advocates cross-disciplinary integration,and aims to cultivate compound talents equipped to tackle future challenges.In 2022,the Ministry of Education issued the“Compulsory Education Information Technology Curriculum(2022 Edition),”emphasizing the core literacy of information science and technology and the integration of interdisciplinary disciplines,and encouraging the teaching mode suitable for discipline characteristics.The 6E teaching mode is a student-centered teaching strategy characterized by active exploration and cross-disciplinary integration.This article innovatively designed the“STEM+”6E teaching mode,which is applied to junior high school information technology teaching,which can better achieve core literacy teaching goals.
文摘Objective:To analyze the value of using virtual reality combined with the flipped classroom teaching model in teaching cardiopulmonary resuscitation(CPR).Methods:Two classes of our nursing program were randomly selected for the study from September 2022 to September 2023,Class A(52 students,conventional teaching method)and Class B(52 students,virtual reality combined with flipped classroom teaching mode).The assessment scores and independent learning ability scores of the students in the two classes were compared.Results:CPR theory and operation scores,passing rate,and independent learning ability scores of Class B were higher than those of Class A(P<0.05).Conclusion:the use of virtual reality combined with the flipped classroom teaching mode in CPR teaching is conducive to the improvement of students’assessment scores and independent learning ability.
基金This work was supported by the National Natural Science Foundation of China(Nos.51878354&51308301)the Natural Science Foundation of Jiangsu Province(Nos.BK20181402&BK20130978)+3 种基金333 Talent High-Level Project of Jiangsu ProvinceQinglan Project of Jiangsu Higher Education Institutionsand the Ministry of Housing and Urban-Rural Science Project of Jiangsu Province under Grant(No.2021ZD10)Any research results expressed in this paper are those of the writer(s)and do not necessarily reflect the views of the foundations.
文摘Bamboo is an eco-friendly material with light weight,high strength,short growth cycle and high sustainability,which is widely used in building structures.Engineered bamboo has further promoted the development of modern bamboo structures due to its unrestricted size and shape.However,as a fiber-reinforced material,fracture damage,especially Mode I fracture damage,becomes the most likely damage mode of its structure,so Mode I fracture characteristics are an important subject in the research of mechanical properties of bamboo.This paper summarizes the current status of experimental research on the Mode I fracture properties of bamboo based on the three-point bending(TPB)method,the single-edge notched beam(SENB)method,the compact tension(CT)method and the double cantilever beam(DCB)method,compares the fracture toughness of different species of bamboo,analyzes the toughening mechanisms and fracture damage modes,discusses the applicability of different theoretical calculation methods,and makes suggestions for future research priorities,aiming to provide a reference for future research and engineering applications in related fields.
基金National Natural Science Foundation of China(Nos.11827810,11875177,12105189 and 12075155)International Atomic Energy Agency Research(No.22733)National Magnetic Confinement Fusion Program of China(No.2019YFE03010001)。
文摘A quasi-coherent(QC)mode was observed in the core region of low-density ohmic plasmas in Sino-UNIted Spherical Tokamak.In experiments on the QC mode,two sets of moveable Langmuir probes(LPs)were used to measure the local parameters including floating potential,electron temperature,electron density,and so on,as well as their profiles.To monitor the magnetohydrodynamic activities,a Mirnov probe was used to measure the poloidal magnetic fluctuation.The QC mode can be seen in the spectra of floating potential,but there is no similar peak in the spectra of magnetic fluctuation.Thus,the QC mode is probably electrostatic.By analyzing the electrostatic potential fluctuations from the LPs,the features of the QC mode including frequency,wavenumber,propagation direction,and dependence on collisionality are identified,which are consistent with the characteristics of dissipative trapped electron mode.
基金Project supported by the Research Foundation of Education Bureau of Hunan Province,China (Grant No.21B0648)the National Natural Science Foundation of China (Grant Nos.11805239,12075282,and 11775268)the Natural Science Foundation of Hunan Province,China (Grant No.2019JJ50011)。
文摘The linear behavior of the dominant unstable mode(m=2,n=1)and its high order harmonics(m=2n,n≥2)are numerically investigated in a reversed magnetic shear cylindrical plasma with two q=2 rational surfaces on the basis of the non-reduced magnetohydrodynamics(MHD)equations.The results show that with low beta(beta is defined as the ratio of plasma pressure to magnetic field pressure),the dominant mode is a classical double tearing mode(DTM).However,when the beta is sufficiently large,the mode is driven mainly by plasma pressure.In such a case,both the linear growth rate and mode structures are strongly affected by pressure,while almost independent of the resistivity.This means that the dominant mode undergoes a transition from DTM to pressure-driven mode with the increase of pressure,which is consistent with the experimental result in ASDEX Upgrade.The simulations also show that the distance between two rational surfaces has an important influence on the pressure needed in mode transition.The larger the distance between two rational surfaces,the larger the pressure for driving the mode transition is.Motivated by the phenomena that the high-m modes may dominate over low-m modes at small inter-resonance distance,the high-m modes with different pressures and q profiles are studied too.
基金supported by the Science and Technology Plan of Shenzhen(JCYJ20170818114107730,JCYJ20180306174923335)The General Research Fund(projects 16205321,16214619)from the Hong Kong Research Grant Council,Innovation Technology Fund(GHP/014/19SZ)+2 种基金Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory(2020B1212030010)Foshan Innovative and Entrepreneurial Research Team Program(2018IT100031)the support from the Center for 1D/2D Quantum Materials and the State Key Laboratory of Advanced Displays and Optoelectronics Technologies at HKUST。
文摘The high-density,vertically aligned retinal neuron array provides effective vision,a feature we aim to replicate with electronic devices.However,the conventional complementary metal-oxide-semiconductor(CMOS)image sensor,based on separate designs for sensing,memory,and processing units,limits its integration density.Moreover,redundant signal communication significantly increases energy consumption.Current neuromorphic devices integrating sensing and signal processing show promise in various computer vision applications,but there is still a need for frame-based imaging with good compatibility.In this study,we developed a dual-mode image sensor based on a high-density all-inorganic perovskite nanowire array.The device can switch between frame-based standard imaging mode and neuromorphic imaging mode by applying different biases.This unique bias-dependent photo response is based on a well-designed energy band diagram.The biomimetic alignment of nanowires ensures the potential for high-resolution imaging.To further demonstrate the imaging ability,we conducted pattern reconstruction in both modes with a 10×10 crossbar device.This study introduces a novel image sensor with high compatibility and efficiency,suitable for various applications including computer vision,surveillance,and robotics.
基金supported by National Natural Science Foundation of China(No.11835010)by the National Key Research and Development Program of China(Nos.2019YFE03030004 and 2022YFE031000001)。
文摘Both current and pressure coupling schemes have been adopted in the hybrid kinetic–magnetohydrodynamic code CLT-K recently.Numerical equivalences between these two coupling schemes are strictly verified under different approximations.First,when considering only the perturbed distribution function of energetic particles(EPs),the equivalence can be proved analytically.Second,when both the variations of the magnetic field and the EP distribution function are included,the current and pressure coupling schemes numerically produce the same result in the nonlinear simulations.On this basis,the influences of co-/counter-passing and trapped EPs on the linear stabilities of the m/n=2/1 tearing mode(TM)have been investigated(where m and n represent the poloidal and toroidal mode numbers,respectively).The results of scanningβh of EPs show that the co-passing and trapped EPs are found to stabilize the TM,while the counter-passing EPs tend to destabilize the TM.The behind(de)stabilization mechanisms of the TM by EPs are carefully analyzed.Furthermore,after exceeding critical EP betas,the same branch of the high-frequency mode is excited by co-/counterpassing and trapped EPs,which is identified as the m/n=2/1 energetic particle mode.
文摘Modern apprenticeship is a talent cultivation mode of deep integration between schools and enterprises,and an effective way for higher vocational colleges and universities to improve the quality of talent cultivation and realize professional service to society.Guangxi College for Preschool Education of Special Education College of Applied Behavior Analysis cooperates with Guangxi Youzhuan Special Children Care Service Center to coeducate rehabilitation teachers of autistic children using the modern apprenticeship mode,constructs school-enterprise synergistic cultivation mechanism,promotes the integration of enrollment and recruitment,improves the system and standard of talent cultivation,builds the faculty team that is mutually employed by the school and enterprise,establishes the guarantee for the management system of modern apprenticeship,and so on.The practice has been carried out with the initial experience gained.However,the construction of a long-term operation mechanism of the modern apprenticeship mode still requires consideration of the contradiction with the traditional cultivation mode and the construction of a perfect evaluation system.
文摘A detailed analysis of mode II stress intensity factors(SIFs) for the double edge cracked Brazilian disk subjected to different diametral compression is presented using a weight function method. The mode II SIFs at crack tips can be obtained by simply calculating an integral of the product of mode II weight function and the shear stress on the prospective crack faces of uncracked disk loaded by a diametral compression. A semi-analytical formula for the calculation of normalized mode II SIF, f _Ⅱ, is derived for different crack lengths (from 0.1 to 0.7) and inclination angles (from 10° to 75°) with respect to loading direction. Comparison between the obtained results and finite element method solutions shows that the weight function method is of high precision. Combined with the authors previous work on mode I fracture analysis, the new specimen geometry can be used to study fracture through any combination of mode I and mode II loading by a simple alignment of the crack relative to the diameter of compression loading, and to obtain pure mode II crack extension. Another advantage of this specimen geometry is that it is available directly from rock core and is also easy to fabricate.
文摘Prediction of mode I fracture toughness(KIC) of rock is of significant importance in rock engineering analyses. In this study, linear multiple regression(LMR) and gene expression programming(GEP)methods were used to provide a reliable relationship to determine mode I fracture toughness of rock. The presented model was developed based on 60 datasets taken from the previous literature. To predict fracture parameters, three mechanical parameters of rock mass including uniaxial compressive strength(UCS), Brazilian tensile strength(BTS), and elastic modulus(E) have been selected as the input parameters. A cluster of data was collected and divided into two random groups of training and testing datasets.Then, different statistical linear and artificial intelligence based nonlinear analyses were conducted on the training data to provide a reliable prediction model of KIC. These two predictive methods were then evaluated based on the testing data. To evaluate the efficiency of the proposed models for predicting the mode I fracture toughness of rock, various statistical indices including coefficient of determination(R2),root mean square error(RMSE), and mean absolute error(MAE) were utilized herein. In the case of testing datasets, the values of R2, RMSE, and MAE for the GEP model were 0.87, 0.188, and 0.156,respectively, while they were 0.74, 0.473, and 0.223, respectively, for the LMR model. The results indicated that the selected GEP model delivered superior performance with a higher R2value and lower errors.
基金Project supported by the State Key Program of National Natural Science Foundation of China(No.11332007)the Young Scientists Fund of the National Natural Science Foundation of China(No.11402167)
文摘The instability of the Mack mode is destabilized by wall-cooling in a high speed boundary layer. The aim of this paper is to study the mechanism of the wall cooling effect on the Mack mode instability by numerical methods. It is shown that the wall-cooling can destabilize the Mack mode instability, similar to the previous conclusions with the exception that the Mack mode instability can be stabilized by wall-cooling if the wall temperature is extremely low. The reversed wall temperature is related to a freestream condition. If the Mach number increases to a large enough value, e.g., about 7, the reversed wall temperature will tend to be zero. It seems that the Mack mode instability is determined by the region between the boundary layer edge and the critical layer. When the wall temperature decreases, this region becomes wider, and the boundary layer becomes more unstable. Additionally, a relative supersonic unstable mode can be observed when the velocity of the critical layer is less than 1 - liMa or is cancelled by the wall-cooling effect. These results provide a deeper understanding on the wall-cooling effect in high speed boundary layers.
基金Supported by the National Basic Research Program of China under Grant No 2014CB340102the National Natural Science Foundation of China under Grant Nos 61474111 and 61274046
文摘Two-mode converters at 1.3μm, aiming at applications in mode-division multiplexing in Ethernet systems, are proposed and experimentally demonstrated. Based on multimode interference couplers, the two-mode converters with 50% and 66% mode conversion efficiencies are designed and fabricated on InP substrates. AIode conver- sion from the fundamental mode (TEo) to the first order mode (TE1) is successfully demonstrated within the wavelength range of 1280-1320nm. The 1.3-μm mode converters should be important devices in mode-division multiplexing systems in Ethernet systems.
基金Project supported by the National Natural Science Foundation of China(No.11332007)
文摘Nonlinear interactions of the two-dimensional (2D) second mode with oblique modes are studied numerically in a Mach 6.0 fiat-plate boundary layer, focusing on its selective enhancement effect on amplification of different oblique waves. Evolution of oblique modes with various frequencies and spanwise wavenumbers in the presence of 2D second mode is simulated successively, using a modified parabolized stability equation (PSE) method, which is able to simulate interaction of two modes with different frequen- cies efficiently. Numerical results show that oblique modes in a broad band of frequencies and spanwise wavenumbers can be enhanced by the finite amplitude 2D second mode instability wave. The enhancement effect is accomplished by interaction of the 2D second mode, the oblique mode, and a forced mode with difference frequency. Two types of oblique modes are found to be more amplified, i.e., oblique modes with frequency close to that of the 2D second mode and low-frequency first mode oblique waves. Each of them may correspond to one type of transition routes found in transition experiments. The spanwise wavenumber of the oblique wave preferred by the nonlinear interaction is also determined by numerical simulations.
文摘VLF (very low frequency) mode instability with parallel AC electric field was studied for generalized loss-cone distribution with an index j, which is reducible to bi-Maxwellian, loss- cone and delta function for j = 0, 1 and co. The particle trajectories and dispersion relation are obtained through a kinetic approach and method of characteristic solutions. The calculations are compared with the observations of low frequency waves of Voyager 2. The growth rate of plasma parameters suited to magnetosphere of Uranus is obtained. It is inferred that the magnitude as well as frequency of AC (alternating current) field increases the growth rate and widen the band width significantly. In addition to temperature anisotropy, particles in plasma having generalized loss-cone distribution provide an additional source of energy.
基金Supported by Foundation of Science and Technology Bureau of Langfang City(2010023179)~~
文摘The paper had analyzed connotation of green agriculture,and pointed out that developing green agriculture is the need to realize socialist new rural construction,the important guarantee for people's consumption safety and life quality improvement,and the realistic requirement of improvement of agricultural competitiveness.Developing green agriculture could promote strategic adjustment of agricultural structure,and accelerate agricultural industrialization.After analysis of green agriculture development in Langfang City,it pointed out that the development results consisted in that green agricultural base and mode began to take shape,agricultural products' quality supervision and detection system had gradually become perfect and rural environment initially improved.Meanwhile,problems existing in green agricultural development of Langfang City were analyzed,which were unclear understanding of connotation of green agriculture,insufficient support from government and lack of capital investment,imperfect green agricultural production and supporting technology,late development of green agricultural products' market and incomplete marketing network and market system.Through study on current green agricultural development mode of Langfang City,it was hoped to provide reference for further study.
文摘OBE theory focuses on students’learning outcomes and application ability,which is consistent with the requirements of the new curriculum standard.The paper attempts to apply OBE theory to innovate the construction of English classroom teaching mode in senior high schools from aspects of teaching aims,teaching activities,teaching assessments and application activities.Results show that the application of OBE in high schools is beneficial to the development of English teaching and students'learning.
基金supported in part by the National Basic Research Program of China (No. JCKY2016203B032)
文摘The identification result of operational mode is eurychoric while operational mode identification is investigated under ambient excitation,which is influenced by the signal size and the time interval.The operational mode identification method,which is based on the sliding time window method and the eigensystem realization algorithm(ERA),is investigated to improve the identification accuracy and stability.Firstly,the theory of the ERA method is introduced.Secondly,the strategy for decomposition and implementation is put forward,including the sliding time window method and the filtration method of modes.At last,an example is studied,where the model of a cantilever beam is built and the white noise exciting is input.Results show that the operational mode identification method can realize the modes,and has high robustness to the signal to noise ratio and signal size.
文摘By simulating edge dislocation emissions from a mode I crack tip along multiple inclined slip planes, the plastic zone and dislocation-free zone around the crack tip are obtained. It is found that the shape of the mode I plastic zone consists of two leaning forward loops which is better agreement with experimental observations. Except at the crack tip there are also stress peaks in front of the crack tip. A formula of the maximum peak stress as a function of the applied stress intensity factor and the friction stress has been regressed.