Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fi...Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fibrils(CEFs)as a class of deagglomerated binder for high-mass-loading electrodes.Derived from natural wood,CEF represents the most fundamental unit of cellulose with nanoscale diameter.The preparation of the CEFs involves the modulation of intermolecular hydrogen bonding by the treatment with a proton acceptor and a hydrotropic agent.This elementary deagglomeration of the cellulose fibers increases surface area and anionic charge density,thus promoting uniform dispersion with carbon conductive additives and suppressing interfacial side reactions at electrodes.Consequently,a homogeneous redox reaction is achieved throughout the electrodes.The resulting CEF-based cathode(overlithiated layered oxide(OLO)is chosen as a benchmark electrode active material)exhibits a high areal-mass-loading(50 mg cm^(-2),equivalent to an areal capacity of 12.5 mAh cm^(-2))and a high specific energy density(445.4 Wh kg–1)of a cell,which far exceeds those of previously reported OLO cathodes.This study highlights the viability of the deagglomerated binder in enabling sustainable high-mass-loading electrodes that are difficult to achieve with conventional synthetic polymer binders.展开更多
This study investigates effective methods for integrating Dalcroze Eurhythmics into elementary dance education,highlighting its necessity in fostering children’s holistic development and enriching teaching content.Th...This study investigates effective methods for integrating Dalcroze Eurhythmics into elementary dance education,highlighting its necessity in fostering children’s holistic development and enriching teaching content.The research proposes strategies such as incorporating Eurhythmics elements into dance choreography and rhythm training,and utilizing game-based teaching to spark student interest and enhance physical coordination and artistic expression.Despite challenges like insufficient teacher expertise and inadequate teaching resources,this paper suggests solutions including strengthening teacher training,optimizing resource allocation,and integrating technology.Future research should focus on long-term impact assessment and refining evaluation systems to promote the standardized development of Eurhythmics in elementary dance education.展开更多
The 5E model includes Engagement,Exploration,Explanation,Elaboration,and Evaluation,with“Evaluation”at the end,conflicting with teaching learning-evaluation consistency.Thus,formative levaluation is integrated into ...The 5E model includes Engagement,Exploration,Explanation,Elaboration,and Evaluation,with“Evaluation”at the end,conflicting with teaching learning-evaluation consistency.Thus,formative levaluation is integrated into the first four stages,and a summative evaluation table is designed for the fifth,enabling students to self-evaluate and reflect.Elementary school English picture book teaching is used as an example to demonstrate the optimized model's application.展开更多
The widespread adoption of the internet has provided new platforms and possibilities for Chinese language instruction.Students can utilize online resources or mobile devices for learning outside the classroom,while te...The widespread adoption of the internet has provided new platforms and possibilities for Chinese language instruction.Students can utilize online resources or mobile devices for learning outside the classroom,while teachers can shift the“intensive instruction”component of comprehensive Chinese courses to extracurricular settings.This approach enables increased practice time during class sessions,truly placing the learner at the center of the educational process.The flipped classroom model aligns with this philosophy and complements the disciplinary characteristics of comprehensive Chinese courses.In practice,implementing the O-PIRTAS universal flipped classroom model revealed its effectiveness in enhancing oral proficiency and overall competency.However,it is essential to concurrently address students’writing skills and cultivate their awareness of the flipped classroom approach.展开更多
With the rapid development of Teaching Chinese as a Foreign Language(TCFL),improving teaching quality requires integrating advanced pedagogical concepts.Multimodal teaching,which employs various symbolic modes to enga...With the rapid development of Teaching Chinese as a Foreign Language(TCFL),improving teaching quality requires integrating advanced pedagogical concepts.Multimodal teaching,which employs various symbolic modes to engage students’multiple senses,is a highly effective approach.Introducing multimodal theory into TCFL education can enhance teaching efficiency and improve students’communication skills.This paper applies multimodal theory to TCFL,using the elementary Chinese comprehensive course“My Family”as a case study to propose a detailed teaching design,followed by evaluation and reflection.The aim of this teaching design is to deepen the understanding of multimodal theory and provide additional reference for the TCFL.展开更多
This study investigated the perceptions of English educators and supervisors in Jeddah Governorate regarding the process of teaching English to elementary students.A survey was conducted using a sample size of 94 educ...This study investigated the perceptions of English educators and supervisors in Jeddah Governorate regarding the process of teaching English to elementary students.A survey was conducted using a sample size of 94 educators and 10 supervisors.The data indicate that respondents considered English instruction at the elementary level essential for expanding kids’perspectives,improving academic performance,and promoting international involvement.The main advantages cited are the development of English language skills and the promotion of early education.Although not as easily noticeable,the disadvantages include potential negative impacts on an individual’s proficiency in Arabic and their sense of national identification.The highlighted challenges encompass insufficient teacher training,student reluctance towards English,limited resources,and school disparities.The proposed techniques focused on prioritizing English instructors’training,ensuring the use of appropriate content,utilizing technology,and promoting awareness of students and educators.The current research found different obstacles in teaching English at elementary stages.To overcome these obstacles,it will be essential to enhance teacher competencies,develop efficient teaching methods,get the backing of stakeholders,assign adequate resources,and carry out continuous evaluations.Further research can also contribute to a better understanding of how early English learning impacts on Arabic identity and proficiency.展开更多
Present studies in physics assume that elementary particles are the building blocks of all matter, and that they are zero-dimensional objects which do not occupy space. The new I-Theory predicts that elementary partic...Present studies in physics assume that elementary particles are the building blocks of all matter, and that they are zero-dimensional objects which do not occupy space. The new I-Theory predicts that elementary particles do indeed have a substructure, three dimensions, and occupy space, being composed of fundamental particles called I-particles. In this article we identify the substructural pattern of elementary particles and define the quanta of energy that form each elementary particle. We demonstrate that the substructure comprises two classes of quanta which we call “attraction quanta” and “repulsion quanta”. We create a model that defines the rest-mass energy of each elementary particle and can predict new particles. Lastly, in order to incorporate this knowledge into the contemporary models of science, a revised periodic table is proposed.展开更多
The uncertainty principle is a fundamental principle of quantum mechanics, but its exact mathematical expression cannot obtain correct results when used to solve theoretical problems such as the energy levels of hydro...The uncertainty principle is a fundamental principle of quantum mechanics, but its exact mathematical expression cannot obtain correct results when used to solve theoretical problems such as the energy levels of hydrogen atoms, one-dimensional deep potential wells, one-dimensional harmonic oscillators, and double-slit experiments. Even after approximate treatment, the results obtained are not completely consistent with those obtained by solving Schrödinger’s equation. This indicates that further research on the uncertainty principle is necessary. Therefore, using the de Broglie matter wave hypothesis, we quantize the action of an elementary particle in natural coordinates and obtain the quantization condition and a new deterministic relation. Using this quantization condition, we obtain the energy level formulas of an elementary particle in different conditions in a classical way that is completely consistent with the results obtained by solving Schrödinger’s equation. A new physical interpretation is given for the particle eigenfunction independence of probability for an elementary particle: an elementary particle is in a particle state at the space-time point where the action is quantized, and in a wave state in the rest of the space-time region. The space-time points of particle nature and the wave regions of particle motion constitute the continuous trajectory of particle motion. When an elementary particle is in a particle state, it is localized, whereas in the wave state region, it is nonlocalized.展开更多
This study focuses on the practical effects of moral and legal education in elementary schools,examining its role in shaping students’behavioral habits and how optimizing educational methods and content can more effe...This study focuses on the practical effects of moral and legal education in elementary schools,examining its role in shaping students’behavioral habits and how optimizing educational methods and content can more effectively promote students’holistic development.The article systematically analyzes the goals,methods,and outcomes of moral and legal education,delving into the interaction mechanisms between education and behavioral habits.Additionally,it proposes further optimization strategies.This research not only deepens our understanding of the essence of moral and legal education but also provides valuable insights for policymakers,teachers,and parents.It aims to drive the reform and innovation of moral and legal education,ultimately enhancing the overall quality of students.展开更多
Inheriting and promoting the excellent traditional Chinese culture should begin with the youth,as elementary school aesthetic education plays a crucial role in this process of cultural dissemination.At present,element...Inheriting and promoting the excellent traditional Chinese culture should begin with the youth,as elementary school aesthetic education plays a crucial role in this process of cultural dissemination.At present,elementary school aesthetic education mainly focuses on traditional fields such as art,music,dance,calligraphy,etc.,and there is still much room for innovation in communication carriers and paths.Based on this status quo,combining professional and regional advantages,this article proposes to take Qilu characteristic costume culture as a carrier to integrate the innovation of excellent traditional Chinese culture into elementary school aesthetic education.It aims to cultivate humanistic literacy and a sense of belonging in school-age children and establish cultural confidence.展开更多
Cracks resulting from cyclic wetting and drying of expansive soils create discontinuities and anisotropy in the soil.The representative elementary volume(REV)defined by the continuous-media theory cannot be applied to...Cracks resulting from cyclic wetting and drying of expansive soils create discontinuities and anisotropy in the soil.The representative elementary volume(REV)defined by the continuous-media theory cannot be applied to cracked expansive soils that are considered discontinuous media.In this study,direct shear tests of three different scales(30 cm^(2),900 cm^(2),1963 cm^(2))and crack image analysis were carried out on undisturbed soil samples subjected to drying-wetting cycles in-situ.The REV size of expansive soil was investigated using the crack intensity factor(CIF)and soil cohesion.The results show that soil cohesion decreased with increasing sample area,and the development of secondary cracks further exacerbated the size effect of sample on cohesion of the soil.As shrinkage cracks developed,the REV size of the soil gradually increased and plateaued after 3−5 cycles.Under the same drying-wetting cycle conditions,the REV size determined using soil cohesion(REV-C)is 1.75 to 2.97 times the REV size determined using CIF(REV-CIF).Under the influence of shrinkage cracks,the average CIF is positively correlated with the REV size determined using different maximum permissible errors,with the coefficient of correlation greater than 0.9.A method for determining the REV-C based on crack image analysis is proposed,and the REV-C of expansive soil in the study area under different exposure times is given.展开更多
In this note, we consider the interactions of elementary waves for the traffic flow model proposed by Aw and Rascle when the vacuum is not involved. The solutions are obtained constructively and globally when the init...In this note, we consider the interactions of elementary waves for the traffic flow model proposed by Aw and Rascle when the vacuum is not involved. The solutions are obtained constructively and globally when the initial data consist of three pieces of constant states. Furthermore, it can be found that the Riemann solutions are stable with respect to such small perturbations of the initial data in this particular situation by investigating the limits of the solutions as the perturbed parameter ε goes to zero.展开更多
Large active wing deformation is a significant way to generate high aerodynamic forces required in bat＇s flapping flight. Besides the twisting, elementary morphing models of a bat wing are proposed, including wing-be...Large active wing deformation is a significant way to generate high aerodynamic forces required in bat＇s flapping flight. Besides the twisting, elementary morphing models of a bat wing are proposed, including wing-bending in the spanwise direction,wing-cambering in the chordwise direction, and wing area-changing. A plate of aspect ratio 3 is used to model a bat wing, and a three-dimensional unsteady panel method is used to predict the aerodynamic forces. It is found that the cambering model has great positive influence on the lift, followed by the area-changing model and then the bending model. Further study indicates that the vortex control is a main mechanism to produce high aerodynamic forces. The mechanisms of aerodynamic force enhancement are asymmetry of the cambered wing and amplification effects of wing area-changing and wing bending. Lift and thrust are generated mainly during downstroke, and they are almost negligible during upstroke by the integrated morphing model-wing.展开更多
Elementary flux mode （EFM） analysis was used in the metabolic analysis of central carbon metabolism in Saccharomyces cerevisiae based on constructed cellular network. Calculated from the metabolic model, the ethanol...Elementary flux mode （EFM） analysis was used in the metabolic analysis of central carbon metabolism in Saccharomyces cerevisiae based on constructed cellular network. Calculated from the metabolic model, the ethanol-producing pathway No. 37 furthest converts the substrate into ethanol among the 78 elementary flux modes. The in silico metabolic phenotypes predicted based on this analysis fit well with the fermentation performance of the engineered strains, KAM3 and KAMll, which confirmed that EFM analysis is valid to direct the construction of Saccharomyces cerevisiae engineered strains, to increase the ethanol yield.展开更多
In this paper, the obtained experimental results concerning creation of bulk elementary excitations （BEEs） in isotopically pure liquid ^4He at low temperatures -60 mK are discussed. Positive rotons＇ （R^＋-rotons）...In this paper, the obtained experimental results concerning creation of bulk elementary excitations （BEEs） in isotopically pure liquid ^4He at low temperatures -60 mK are discussed. Positive rotons＇ （R^＋-rotons） creation by a pulsed heater was studied. Signals were recorded for the following quantum processes： quantum evaporation of ^4He-atoms from the free liquid-helium surface by the BEEs of the liquid helium-Ⅱ, and BEEs reflection from the free surface back into the bulk liquid. Typical signals are shown, and ratios of signal amplitudes are evaluated. For long heater pulses from 5 to 10 μs, appearance of the second atomic cloud consisting of evaporated ^4He-atoms was observed in addition to the first atomic cloud. It is thought that the first atomic cloud of the evaporated helium atoms consists of very fast ^4He-atoms with energies ～35 K evaporated by positive rotons with the special energies ～17 K （～2ER～2×8.6 K with ER representing the roton minimum energy） corresponding to the third non-dispersive Zakharenko wave. The second cloud of slower ^4He-atoms was created by surface elementary excitations （SEEs or ripplons） possessing the special energies ～7.15 K representing the binding energy. It was assumed that such SEEs can be created by phonons incoming to the liquid surface with special energies ～6.2 K corresponding to the first non-dispersive Zakharenko wave which can interact at the liquid surface with the same phonons already reflected from the surface for long heater pulses. Also, some pulsed-heater characteristics were studied in order to better understand the features of such heaters in low temperature experiments.展开更多
The radiation fields generated when a charged particle is incident on or moving away from a perfectly conducting plane are obtained. These fields are known in the literature as transition radiation. The field equation...The radiation fields generated when a charged particle is incident on or moving away from a perfectly conducting plane are obtained. These fields are known in the literature as transition radiation. The field equations derived thus are used to evaluate the energy, momentum and the action associated with the radiation. The results show that for a charged particle moving with speed ν, the longitudinal momentum associated with the transition radiation is approximately equal to ΔU/c for values of ?1- ν/c smaller than about 10-3 where ΔU is the total radiated energy dissipated during the interaction and cis the speed of light in free space. The action of the radiation, defined as the product of the total energy dissipated and the duration of the emission, increases as 1- ν/c decreases and, for an electron, it becomes equal to h/4π when ν = c - νm where νm is the speed pertinent to the lowest possible momentum associated with a particle confined inside the universe and?h is the Planck constant. Combining these results with Heisenberg’s uncertainty principle, an expression that predicts the value of the elementary charge is derived.展开更多
In this paper, we mainly study some properties of elementary n-Lie algebras, and prove some necessary and sufficient conditions for elementary n-Lie algebras. We also give the relations between elementary n-algebras a...In this paper, we mainly study some properties of elementary n-Lie algebras, and prove some necessary and sufficient conditions for elementary n-Lie algebras. We also give the relations between elementary n-algebras and E-algebras.展开更多
Using the tools of distinct excluded blocks, computational search and symbolic dynamics, the classification problem of all 256 elementary cellular automata is discussed from the point of view of time series generated ...Using the tools of distinct excluded blocks, computational search and symbolic dynamics, the classification problem of all 256 elementary cellular automata is discussed from the point of view of time series generated by them,and examples in each class are provided to explain the methods used.展开更多
In this paper, using the characteristic analysis method, we study the relativistic Euler equations of conservation laws in energy and momentum in special relativity. The interactions of elementary waves for the relati...In this paper, using the characteristic analysis method, we study the relativistic Euler equations of conservation laws in energy and momentum in special relativity. The interactions of elementary waves for the relativistic Euler equations are shown. The collision of two shocks, two centered rarefaction waves, a shock and a rarefaction wave yield corresponding ransmitted waves. The overtaking of two shocks appears a transmitted shock wave, together with a reflected centered rarefaction wave.展开更多
基金supported by the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration and Ministry of Trade,Industry and Energy of Korean government under grant No 23-CM-AI-08.
文摘Amidst the ever-growing interest in high-mass-loading Li battery electrodes,a persistent challenge has been the insufficient continuity of their ion/electron conduction pathways.Here,we propose cellulose elementary fibrils(CEFs)as a class of deagglomerated binder for high-mass-loading electrodes.Derived from natural wood,CEF represents the most fundamental unit of cellulose with nanoscale diameter.The preparation of the CEFs involves the modulation of intermolecular hydrogen bonding by the treatment with a proton acceptor and a hydrotropic agent.This elementary deagglomeration of the cellulose fibers increases surface area and anionic charge density,thus promoting uniform dispersion with carbon conductive additives and suppressing interfacial side reactions at electrodes.Consequently,a homogeneous redox reaction is achieved throughout the electrodes.The resulting CEF-based cathode(overlithiated layered oxide(OLO)is chosen as a benchmark electrode active material)exhibits a high areal-mass-loading(50 mg cm^(-2),equivalent to an areal capacity of 12.5 mAh cm^(-2))and a high specific energy density(445.4 Wh kg–1)of a cell,which far exceeds those of previously reported OLO cathodes.This study highlights the viability of the deagglomerated binder in enabling sustainable high-mass-loading electrodes that are difficult to achieve with conventional synthetic polymer binders.
文摘This study investigates effective methods for integrating Dalcroze Eurhythmics into elementary dance education,highlighting its necessity in fostering children’s holistic development and enriching teaching content.The research proposes strategies such as incorporating Eurhythmics elements into dance choreography and rhythm training,and utilizing game-based teaching to spark student interest and enhance physical coordination and artistic expression.Despite challenges like insufficient teacher expertise and inadequate teaching resources,this paper suggests solutions including strengthening teacher training,optimizing resource allocation,and integrating technology.Future research should focus on long-term impact assessment and refining evaluation systems to promote the standardized development of Eurhythmics in elementary dance education.
基金This paper is funded by Project Information:2023 Guangdong Undergraduate Colleges and Universities Teaching Quality and Teaching Reform Project Construction Project,Project Name:Action Research on Whole-area Nurturing of English Reading Teaching in Universities,Secondary and Primary Schools under the Perspective of Discipline Nurturing.Project serial number:895.
文摘The 5E model includes Engagement,Exploration,Explanation,Elaboration,and Evaluation,with“Evaluation”at the end,conflicting with teaching learning-evaluation consistency.Thus,formative levaluation is integrated into the first four stages,and a summative evaluation table is designed for the fifth,enabling students to self-evaluate and reflect.Elementary school English picture book teaching is used as an example to demonstrate the optimized model's application.
文摘The widespread adoption of the internet has provided new platforms and possibilities for Chinese language instruction.Students can utilize online resources or mobile devices for learning outside the classroom,while teachers can shift the“intensive instruction”component of comprehensive Chinese courses to extracurricular settings.This approach enables increased practice time during class sessions,truly placing the learner at the center of the educational process.The flipped classroom model aligns with this philosophy and complements the disciplinary characteristics of comprehensive Chinese courses.In practice,implementing the O-PIRTAS universal flipped classroom model revealed its effectiveness in enhancing oral proficiency and overall competency.However,it is essential to concurrently address students’writing skills and cultivate their awareness of the flipped classroom approach.
文摘With the rapid development of Teaching Chinese as a Foreign Language(TCFL),improving teaching quality requires integrating advanced pedagogical concepts.Multimodal teaching,which employs various symbolic modes to engage students’multiple senses,is a highly effective approach.Introducing multimodal theory into TCFL education can enhance teaching efficiency and improve students’communication skills.This paper applies multimodal theory to TCFL,using the elementary Chinese comprehensive course“My Family”as a case study to propose a detailed teaching design,followed by evaluation and reflection.The aim of this teaching design is to deepen the understanding of multimodal theory and provide additional reference for the TCFL.
文摘This study investigated the perceptions of English educators and supervisors in Jeddah Governorate regarding the process of teaching English to elementary students.A survey was conducted using a sample size of 94 educators and 10 supervisors.The data indicate that respondents considered English instruction at the elementary level essential for expanding kids’perspectives,improving academic performance,and promoting international involvement.The main advantages cited are the development of English language skills and the promotion of early education.Although not as easily noticeable,the disadvantages include potential negative impacts on an individual’s proficiency in Arabic and their sense of national identification.The highlighted challenges encompass insufficient teacher training,student reluctance towards English,limited resources,and school disparities.The proposed techniques focused on prioritizing English instructors’training,ensuring the use of appropriate content,utilizing technology,and promoting awareness of students and educators.The current research found different obstacles in teaching English at elementary stages.To overcome these obstacles,it will be essential to enhance teacher competencies,develop efficient teaching methods,get the backing of stakeholders,assign adequate resources,and carry out continuous evaluations.Further research can also contribute to a better understanding of how early English learning impacts on Arabic identity and proficiency.
文摘Present studies in physics assume that elementary particles are the building blocks of all matter, and that they are zero-dimensional objects which do not occupy space. The new I-Theory predicts that elementary particles do indeed have a substructure, three dimensions, and occupy space, being composed of fundamental particles called I-particles. In this article we identify the substructural pattern of elementary particles and define the quanta of energy that form each elementary particle. We demonstrate that the substructure comprises two classes of quanta which we call “attraction quanta” and “repulsion quanta”. We create a model that defines the rest-mass energy of each elementary particle and can predict new particles. Lastly, in order to incorporate this knowledge into the contemporary models of science, a revised periodic table is proposed.
文摘The uncertainty principle is a fundamental principle of quantum mechanics, but its exact mathematical expression cannot obtain correct results when used to solve theoretical problems such as the energy levels of hydrogen atoms, one-dimensional deep potential wells, one-dimensional harmonic oscillators, and double-slit experiments. Even after approximate treatment, the results obtained are not completely consistent with those obtained by solving Schrödinger’s equation. This indicates that further research on the uncertainty principle is necessary. Therefore, using the de Broglie matter wave hypothesis, we quantize the action of an elementary particle in natural coordinates and obtain the quantization condition and a new deterministic relation. Using this quantization condition, we obtain the energy level formulas of an elementary particle in different conditions in a classical way that is completely consistent with the results obtained by solving Schrödinger’s equation. A new physical interpretation is given for the particle eigenfunction independence of probability for an elementary particle: an elementary particle is in a particle state at the space-time point where the action is quantized, and in a wave state in the rest of the space-time region. The space-time points of particle nature and the wave regions of particle motion constitute the continuous trajectory of particle motion. When an elementary particle is in a particle state, it is localized, whereas in the wave state region, it is nonlocalized.
文摘This study focuses on the practical effects of moral and legal education in elementary schools,examining its role in shaping students’behavioral habits and how optimizing educational methods and content can more effectively promote students’holistic development.The article systematically analyzes the goals,methods,and outcomes of moral and legal education,delving into the interaction mechanisms between education and behavioral habits.Additionally,it proposes further optimization strategies.This research not only deepens our understanding of the essence of moral and legal education but also provides valuable insights for policymakers,teachers,and parents.It aims to drive the reform and innovation of moral and legal education,ultimately enhancing the overall quality of students.
基金2022 Teacher Education Research of Taishan College“Research on the Integration Path of Traditional Culture and Elementary School Aesthetic Education Based on Qilu Traditional Characteristic Costumes”(JY-01-202224)。
文摘Inheriting and promoting the excellent traditional Chinese culture should begin with the youth,as elementary school aesthetic education plays a crucial role in this process of cultural dissemination.At present,elementary school aesthetic education mainly focuses on traditional fields such as art,music,dance,calligraphy,etc.,and there is still much room for innovation in communication carriers and paths.Based on this status quo,combining professional and regional advantages,this article proposes to take Qilu characteristic costume culture as a carrier to integrate the innovation of excellent traditional Chinese culture into elementary school aesthetic education.It aims to cultivate humanistic literacy and a sense of belonging in school-age children and establish cultural confidence.
基金Project(41472240)supported by the National Natural Science Foundation of ChinaProjects(2015B25514,2015B17214)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Cracks resulting from cyclic wetting and drying of expansive soils create discontinuities and anisotropy in the soil.The representative elementary volume(REV)defined by the continuous-media theory cannot be applied to cracked expansive soils that are considered discontinuous media.In this study,direct shear tests of three different scales(30 cm^(2),900 cm^(2),1963 cm^(2))and crack image analysis were carried out on undisturbed soil samples subjected to drying-wetting cycles in-situ.The REV size of expansive soil was investigated using the crack intensity factor(CIF)and soil cohesion.The results show that soil cohesion decreased with increasing sample area,and the development of secondary cracks further exacerbated the size effect of sample on cohesion of the soil.As shrinkage cracks developed,the REV size of the soil gradually increased and plateaued after 3−5 cycles.Under the same drying-wetting cycle conditions,the REV size determined using soil cohesion(REV-C)is 1.75 to 2.97 times the REV size determined using CIF(REV-CIF).Under the influence of shrinkage cracks,the average CIF is positively correlated with the REV size determined using different maximum permissible errors,with the coefficient of correlation greater than 0.9.A method for determining the REV-C based on crack image analysis is proposed,and the REV-C of expansive soil in the study area under different exposure times is given.
基金Sponsored by National Natural Science Foundation of China (10901077)China Postdoctoral Science Foundation (201003504+1 种基金 20090451089)Shandong Provincial Doctoral Foundation (BS2010SF006)
文摘In this note, we consider the interactions of elementary waves for the traffic flow model proposed by Aw and Rascle when the vacuum is not involved. The solutions are obtained constructively and globally when the initial data consist of three pieces of constant states. Furthermore, it can be found that the Riemann solutions are stable with respect to such small perturbations of the initial data in this particular situation by investigating the limits of the solutions as the perturbed parameter ε goes to zero.
基金Project supported by the National Natural Science Foundation of China(No.10602061)
文摘Large active wing deformation is a significant way to generate high aerodynamic forces required in bat＇s flapping flight. Besides the twisting, elementary morphing models of a bat wing are proposed, including wing-bending in the spanwise direction,wing-cambering in the chordwise direction, and wing area-changing. A plate of aspect ratio 3 is used to model a bat wing, and a three-dimensional unsteady panel method is used to predict the aerodynamic forces. It is found that the cambering model has great positive influence on the lift, followed by the area-changing model and then the bending model. Further study indicates that the vortex control is a main mechanism to produce high aerodynamic forces. The mechanisms of aerodynamic force enhancement are asymmetry of the cambered wing and amplification effects of wing area-changing and wing bending. Lift and thrust are generated mainly during downstroke, and they are almost negligible during upstroke by the integrated morphing model-wing.
基金Supported by the National Natural Science Foundation of China （No.2002AA647040）
文摘Elementary flux mode （EFM） analysis was used in the metabolic analysis of central carbon metabolism in Saccharomyces cerevisiae based on constructed cellular network. Calculated from the metabolic model, the ethanol-producing pathway No. 37 furthest converts the substrate into ethanol among the 78 elementary flux modes. The in silico metabolic phenotypes predicted based on this analysis fit well with the fermentation performance of the engineered strains, KAM3 and KAMll, which confirmed that EFM analysis is valid to direct the construction of Saccharomyces cerevisiae engineered strains, to increase the ethanol yield.
文摘In this paper, the obtained experimental results concerning creation of bulk elementary excitations （BEEs） in isotopically pure liquid ^4He at low temperatures -60 mK are discussed. Positive rotons＇ （R^＋-rotons） creation by a pulsed heater was studied. Signals were recorded for the following quantum processes： quantum evaporation of ^4He-atoms from the free liquid-helium surface by the BEEs of the liquid helium-Ⅱ, and BEEs reflection from the free surface back into the bulk liquid. Typical signals are shown, and ratios of signal amplitudes are evaluated. For long heater pulses from 5 to 10 μs, appearance of the second atomic cloud consisting of evaporated ^4He-atoms was observed in addition to the first atomic cloud. It is thought that the first atomic cloud of the evaporated helium atoms consists of very fast ^4He-atoms with energies ～35 K evaporated by positive rotons with the special energies ～17 K （～2ER～2×8.6 K with ER representing the roton minimum energy） corresponding to the third non-dispersive Zakharenko wave. The second cloud of slower ^4He-atoms was created by surface elementary excitations （SEEs or ripplons） possessing the special energies ～7.15 K representing the binding energy. It was assumed that such SEEs can be created by phonons incoming to the liquid surface with special energies ～6.2 K corresponding to the first non-dispersive Zakharenko wave which can interact at the liquid surface with the same phonons already reflected from the surface for long heater pulses. Also, some pulsed-heater characteristics were studied in order to better understand the features of such heaters in low temperature experiments.
文摘The radiation fields generated when a charged particle is incident on or moving away from a perfectly conducting plane are obtained. These fields are known in the literature as transition radiation. The field equations derived thus are used to evaluate the energy, momentum and the action associated with the radiation. The results show that for a charged particle moving with speed ν, the longitudinal momentum associated with the transition radiation is approximately equal to ΔU/c for values of ?1- ν/c smaller than about 10-3 where ΔU is the total radiated energy dissipated during the interaction and cis the speed of light in free space. The action of the radiation, defined as the product of the total energy dissipated and the duration of the emission, increases as 1- ν/c decreases and, for an electron, it becomes equal to h/4π when ν = c - νm where νm is the speed pertinent to the lowest possible momentum associated with a particle confined inside the universe and?h is the Planck constant. Combining these results with Heisenberg’s uncertainty principle, an expression that predicts the value of the elementary charge is derived.
基金The NSF(A2007000138,2005000088)of Hebei Provincethe NSF(y2004034)of Hebei University
文摘In this paper, we mainly study some properties of elementary n-Lie algebras, and prove some necessary and sufficient conditions for elementary n-Lie algebras. We also give the relations between elementary n-algebras and E-algebras.
文摘Using the tools of distinct excluded blocks, computational search and symbolic dynamics, the classification problem of all 256 elementary cellular automata is discussed from the point of view of time series generated by them,and examples in each class are provided to explain the methods used.
基金Project supported by the National Natural Science Foundation of China (Grant No.10671120)
文摘In this paper, using the characteristic analysis method, we study the relativistic Euler equations of conservation laws in energy and momentum in special relativity. The interactions of elementary waves for the relativistic Euler equations are shown. The collision of two shocks, two centered rarefaction waves, a shock and a rarefaction wave yield corresponding ransmitted waves. The overtaking of two shocks appears a transmitted shock wave, together with a reflected centered rarefaction wave.
