The relation between the normal displacement on the surface of a dynamical elliptical crack and the normal stress over the crack surface was studied. The three dimensional elastodynamic equations and Fourier Laplace...The relation between the normal displacement on the surface of a dynamical elliptical crack and the normal stress over the crack surface was studied. The three dimensional elastodynamic equations and Fourier Laplace transforms are used. Based on the influence function and the inversion of integral transforms, one can find that if the distribution of normal displacement on the surface of a dynamic elliptical crack is a polynomial of degree n in x 1 and x 2 , then the normal pressure acting over the ellipse is also a polynomial P n(x 1,x 2) of the same degree in x 1 and x 2 .展开更多
For more than 60 years,Mr.Xu Yuanchong has been devoted to education.He has not only made remarkable achievements in translating from and into Chinese,English,French and other languages,but has also developed his own ...For more than 60 years,Mr.Xu Yuanchong has been devoted to education.He has not only made remarkable achievements in translating from and into Chinese,English,French and other languages,but has also developed his own unique concept of translation.Since 1950,he has always adhered to the“Three Beauties Theory”,believing that translation should not only rely on the original text,but also realize the“beauty of meaning”,“beauty of sound”,and“beauty of form”.Based on Xu Yuanchong’s“Three Beauties Theory”,this paper takes Zheng Zhenduo’s and Feng Tang’s Chinese translations of Stray Birds as an example to explore in depth the specifics of poetry translation theory.The study summarizes the similarities and differences between these two translations in embodying the“three beauties”,providing insights into the Chinese translation techniques of philosophical prose poems.This endeavor seeks to offer valuable insights for the comparative study of Stray Birds translations。展开更多
Traditional Mongolian medicine(TMM)integrates Tibetan and Chinese medicine with indigenous Mongolian practices,focusing on the balance of three core essences:Khii,Shar,and Badgan,derived from the Five Elements-earth,w...Traditional Mongolian medicine(TMM)integrates Tibetan and Chinese medicine with indigenous Mongolian practices,focusing on the balance of three core essences:Khii,Shar,and Badgan,derived from the Five Elements-earth,water,fire,wind,and space.These essences regulate both physical and psychological processes,and their imbalance,often caused by diet,behavior,or environment,leads to disease.TMM utilizes holistic diagnostic methods such as pulse diagnosis,visual inspection,and lifestyle evaluation to identify imbalances of three essences.Treatments include herbal remedies,dietary adjustments,behavior modification,and accessory therapies like moxibustion and massage to restore balance.This mini review examines the philosophical underpinnings,diagnostic techniques,and therapeutic strategies to Khii,Shar,and Badgan,highlighting their importance in both traditional and modern integrative healthcare.展开更多
BACKGROUND Extended care based on self-efficacy theory to elderly patients with intertrochanteric fractures will provide data reference to optimize the care plan of these patients,reduce patients’concurrent mental di...BACKGROUND Extended care based on self-efficacy theory to elderly patients with intertrochanteric fractures will provide data reference to optimize the care plan of these patients,reduce patients’concurrent mental diseases,and improve prognosis.AIM To analyze the value of extended nursing based on the self-efficacy theory in older patients with intertrochanteric fractures.METHODS Older patients with intertrochanteric fractures(n=88)admitted to our hospital between January 2021 and December 2024 were randomly divided into two groups-the control group(n=44,routine nursing)and the observation group(n=44,extended nursing)-via balloting and treated for 12 weeks.The mental state,pain severity,limb function,and self-nursing ability of all patients before and after nursing were analyzed.RESULTS After nursing,the Hamilton Anxiety Scale and General Self-Efficacy Scale scores of patients in the two groups improved.Notably,Hamilton Anxiety Scale and General Self-Efficacy Scale scores in the observation group were lower and higher,respectively,than those in the control group(P<0.05).The pain severity in the observation group(2.64±0.22)was lower than that in the control group(2.85±0.41)(P<0.05).The recovery rate of limb function was higher in the observation group than in the control group(P<0.05).In addition,the self-nursing ability scores of the patients in both groups increased,with a significantly higher score in the observation group(P<0.05).CONCLUSION Extended nursing based on the self-efficacy theory can significantly improve mental state,relieve pain,and promote the recovery of limb function and self-nursing ability in older patients with intertrochanteric fractures.展开更多
BACKGROUND Patients with depression following coronary heart disease often exhibit insufficient psychological resilience and self-care abilities;therefore,emphasis must be placed on nursing interventions.AIM To analyz...BACKGROUND Patients with depression following coronary heart disease often exhibit insufficient psychological resilience and self-care abilities;therefore,emphasis must be placed on nursing interventions.AIM To analyze the application value of problem-oriented education combined with nursing interventions based on the Snyder hope theory model in depressed patients after percutaneous coronary intervention(PCI).METHODS This study included 150 patients diagnosed with PCI postoperative depression because of coronary heart disease between February 2022 and February 2024.Participants were divided into two groups:A control group(n=75)receiving problem-oriented education and an observation group(n=75)receiving combined nursing interventions based on the Snyder hope theory model.Depression status,psychological resilience,self-care ability,and quality of life were compared between the two groups.RESULTS Before nursing interventions,there were no significant differences between the two groups(P>0.05).After the interventions,depression scores decreased while psychological resilience,self-care ability,and quality of life scores increased significantly in the observation group compared to that in the control group,with statistically significant differences noted(P<0.05).This combined approach can enhance psychological resilience,improve self-care abilities,and elevate the overall quality of life,warranting further promotion in clinical practice.CONCLUSION Combination of problem-oriented education and nursing interventions based on the Snyder hope theory model effectively alleviates depression in patients following PCI for coronary heart disease.展开更多
This paper firstly defined the concept of folk culture block,and then analyzed the significance and planning principle of landscape design in folk culture block,and at last expounded landscape planning and design of f...This paper firstly defined the concept of folk culture block,and then analyzed the significance and planning principle of landscape design in folk culture block,and at last expounded landscape planning and design of folk culture block based on theory of three elements of landscape.展开更多
Leadership is a complex process.It is one of the most researched areas around the world.It has gained importance in every walk of life from politics to business and from education to social organizations.According to ...Leadership is a complex process.It is one of the most researched areas around the world.It has gained importance in every walk of life from politics to business and from education to social organizations.According to the study of"Leadership in Adult Education Venues",here has a much more clear recognition of leadership:leadership is a process whereby an individual influences a group of individuals to achieve a common goal.There are many approaches of leadership throughout the study of this class,the three theories of leadership I choose to describe in this paper are:Leader-Member Exchange(LMX)Theory,Transformational Leadership,and Team Leadership.展开更多
The dynamic behavior of a rectangular crack in a three-dimensional (3D) orthotropic elastic medium is investigated under a harmonic stress wave based on the non-local theory. The two-dimensional (2D) Fourier trans...The dynamic behavior of a rectangular crack in a three-dimensional (3D) orthotropic elastic medium is investigated under a harmonic stress wave based on the non-local theory. The two-dimensional (2D) Fourier transform is applied, and the mixed- boundary value problems are converted into three pairs of dual integral equations with the unknown variables being the displacement jumps across the crack surfaces. The effects of the geometric shape of the rectangular crack, the circular frequency of the incident waves, and the lattice parameter of the orthotropic elastic medium on the dynamic stress field near the crack edges are analyzed. The present solution exhibits no stress singularity at the rectangular crack edges, and the dynamic stress field near the rectangular crack edges is finite.展开更多
A three-dimensional Eulerian multiphase model, with closure law according to the kinetic theory of granular flow, was used to study the gas/solid flow behaviors in spout-fluid beds. The influences of the coefficient o...A three-dimensional Eulerian multiphase model, with closure law according to the kinetic theory of granular flow, was used to study the gas/solid flow behaviors in spout-fluid beds. The influences of the coefficient of restitution due to non-ideal particle collisions on the simulated results were tested. It is demonstrated that the simulated result is strongly affected by the coefficient of restitution. Comparison of simulations with experiments in a small spout-fluid bed showed that an appropriate coefficient of restitution of 0.93 was necessary to simulate the flow characteristics in an underdesigned large size of spout-fluid bed coal gasifier with diameter of lm and height of 6m. The internal jet and gas/solid flow patterns at different operating conditions were obtained. The simulations show that an optimal gas/solid flow pattern for coal gasification is found when the spouting gas flow rate is equal to the fluidizing gas flow rate and the total of them is two and a half times the minimum fluidizing gas flow rate. Besides, the radial distributions of particle velocity and gas velocity show similar tendencies; the radial distributions of particle phase pressure due to particle collisions and the particle pseudo-temperature corresponding to the macroscopic kinetic energy of the random particle motion also show similar tendencies. These indicate that both gas drag force and particle collisions dominate the movement of particles.展开更多
In order to meet tracking performance index of three-axis hydraulic simulator, based on classical quantitative feedback theory (QFT), an improved QFT technique is used to synthesize controller of low gain and bandwi...In order to meet tracking performance index of three-axis hydraulic simulator, based on classical quantitative feedback theory (QFT), an improved QFT technique is used to synthesize controller of low gain and bandwidth. By choosing a special nominal plant, the improved method assigns relative magnitude and phase tracking error between system uncertainty and nominal control plant. Relative tracking error induced by system uncertainty is transformed into sensitivity problem and relative tracking error induced by nominal plant forms into a region on Nichols chart. The two constraints further form into a combined bound which is fit for magnitude and phase loop shaping. Because of leaving out pre-filter of classical QFT controller structure, tracking performance is enhanced greatly. Furthermore, a cascaded two-loop control strategy is proposed to heighten control effect. The improved technique's efficacy is validated by simulation and experiment results.展开更多
In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull"...In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull" migration theory, this paper utilizes sectional data from a 2013 survey of farmers in China's Three Gorges Reservoir area to empirically analyze the factors influencing migrant workers' choice of employment location. The results indicate that 60.46% of laborers have migrated from their home province, whereas 39.54% have remained in their home province. Focusing on personal, household, and community characteristics—in addition to the economic characteristics of the sample counties—multinomial logistic regression models reveal that farmer-laborers' employment location decisions are influenced by their personal capital endowment(age, years of education and social networks), family structure(the number of laborers, elders, children and students), home village characteristics(location, economic development level and the degree of relief of the land) and home county economic development level. Notably, male and female laborers' location decisions reveal a converging trend, and their differences are not pronounced. Per capita arable land area has little influence on location decisions, whereas the educational level of laborers has a significant impact. The results differ significantly from those found in previous studies.展开更多
Prandtl’s lifting line theory was generalized to the lifting problem of a three-dimensional hydrofoil in the presence of a free surface. Similar to the classical lifting theory, the singularity distribution method wa...Prandtl’s lifting line theory was generalized to the lifting problem of a three-dimensional hydrofoil in the presence of a free surface. Similar to the classical lifting theory, the singularity distribution method was utilized to solve two-dimensional lifting problems for the hydrofoil beneath the free surface at the air-water interface, and a lifting line theory was developed to correct three-dimensional effects of the hydrofoil with a large aspect ratio. Differing from the classical lifting theory, the main focus was on finding the three-dimensional Green function of the free surface induced by the steady motion of a system of horseshoe vortices under the free surface. Finally, numerical examples were given to show the relationship between the lift coefficient and submergence Froude numbers for 2-D and 3-D hydrofoils. If the submergence Froude number is small free surface effect will be significant registered as the increase of lift coefficient. The validity of these approaches was examined in comparison with the results calculated by other methods.展开更多
it is universal acknowledgement that grammar takes an indispensable place in English learning yet increasing evidences show that there are still serious problems exists in China grammar teaching:low learning motivatio...it is universal acknowledgement that grammar takes an indispensable place in English learning yet increasing evidences show that there are still serious problems exists in China grammar teaching:low learning motivation,goal-oriented teaching mode and traditional deductive approach.Freeman’s Three Dimension Theory(1991)suggests that grammar should be understood as three respective:form,meaning,usage.This thesis analyses the dominant deficiencies which reveals traditional teaching mode only lays emphasis on form or meaning.Neglecting on importance of context obscures mastery of grammar rules by students.By the end of this paper,taking teaching of conditionals as examples,a suggestive teaching model is provided based on Three Dimension Theory(Freeman,1991).展开更多
In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at ...In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at extremely high temperatures.However,stochastic density functional theory(SDFT)can overcome this limitation.Recently,SDFT and the related mixed stochastic–deterministic density functional theory,based on a plane-wave basis set,have been implemented in the first-principles electronic structure software ABACUS[Q.Liu and M.Chen,Phys.Rev.B 106,125132(2022)].In this study,we combine SDFT with the Born–Oppenheimer molecular dynamics method to investigate systems with temperatures ranging from a few tens of eV to 1000 eV.Importantly,we train machine-learning-based interatomic models using the SDFT data and employ these deep potential models to simulate large-scale systems with long trajectories.Subsequently,we compute and analyze the structural properties,dynamic properties,and transport coefficients of warm dense matter.展开更多
Part I of this study proved that the Paraconsistent Annotated Logic using two values (PAL2v), known as the Paraquantum Logic (PQL), can represent the quantum by a model comprising two wave functions obtained from inte...Part I of this study proved that the Paraconsistent Annotated Logic using two values (PAL2v), known as the Paraquantum Logic (PQL), can represent the quantum by a model comprising two wave functions obtained from interference phenomena in the 2W (two-wave) region of Young’s experiment (double slit). With this model represented in one spatial dimension, we studied in the Lattice of the PQL, with their values represented in the set of complex numbers, the state vector of unitary module and its correspondence with the two wave functions. Based on these considerations, we applied the PQL model for obtaining Paraquantum logical states ψ related to energy levels, following the principles of the wave theory through SchrÖdinger’s equation. We also applied the probability theory and Bonferroni’s inequality for demonstrating that quantum wave functions, represented by evidence degrees, are probabilistic functions studied in the PQL Lattice, confirming that the final Paraquantum Logic Model is well suited to studies involving aspects of the wave-particle theory. This approach of quantum theory using Paraconsistent logic allows the interpretation of various phenomena of Quantum Mechanics, so it is quite promising for creating efficient models in the physical analysis and quantum computing processes.展开更多
In this study, we illustrate the effective medium theories in the designs of three-dimensional composite metama- terials of both negative permittivity and negative permeability. The proposed metamaterial consists of r...In this study, we illustrate the effective medium theories in the designs of three-dimensional composite metama- terials of both negative permittivity and negative permeability. The proposed metamaterial consists of random coated spheres with sizes smaller compared to the wavelength embedded in a dielectric host. Simple design rules and formulas following the effective medium models are numerically and analytically presented. We demonstrate that the revised Maxwell-Garnett effective medium theory enables us to design three-dimensional composite metamaterials through the assembly of coated spheres which are random and much smaller than the wavelength of the light. The proposed ap- proach allows for the precise control of the permittivity and the permeability and guides a facile, flexible, and versatile way for the fabrication of composite metamaterials.展开更多
This paper presents a three-dimensional time-dependent nonlinear theory of helix traveling wave tubes for beam- wave interaction. The radio frequency electromagnetic fields are represented as the superposition of azim...This paper presents a three-dimensional time-dependent nonlinear theory of helix traveling wave tubes for beam- wave interaction. The radio frequency electromagnetic fields are represented as the superposition of azimuthally sym- metric waves in a vacuum sheath helix. Coupling impedance is introduced to the electromagnetic field equations' stimulating sources, which makes the theory easier and more flexible to realize. The space charge fields are calculated by electron beam space-charge waves expressed as the superposition solutions of Helmholtz equations. The focusing forces due to either a solenoidal field or a periodic permanent magnetic field is also included. The dynamical equations of electrons are Lorentz equations associating with electromagnetic fields, focusing fields and space-charge fields. The numerically simulated results of a tube are presented.展开更多
The three postulates of the posited dynamic and reversible theory of everything are: 1) the oscil-lating M-theory postulate for the oscillating matter structure, 2) the digital transitional Higgs-reversed Higgs fields...The three postulates of the posited dynamic and reversible theory of everything are: 1) the oscil-lating M-theory postulate for the oscillating matter structure, 2) the digital transitional Higgs-reversed Higgs fields postulate for the digital space structure, and 3) the reversible multiverse post-ulate for all physical laws and phenomena. The posited theory of everything based on the three postulates explains cosmology, the composition (baryonic matter, dark matter, and dark energy) in the universe, the periodic table of elementary particles (quarks, leptons, and bosons), the galaxy evolution, superconductivity, black hole, thermodynamic, and quantum mechanics. Oscillating M-theory is derived from oscillating membrane-string-particle whose space-time dimension number oscillates between 11D and 10D and between 10D and 4D. Space-time dimension number between 10 and 4 decreases with decreasing speed of light, decreasing vacuum energy, and in-creasing rest mass. The digital transitional Higgs-reversed Higgs fields are derived from digital attachment-detachment spaces which couple to particles. Under spontaneous symmetry breaking, the coupling of massless particle to zero-energy attachment space (the space for mass) produces the transitional nonzero-energy Higgs field-particle composite which under spontaneous symmetry restoring produces massive particle on zero-energy attachment space with the longitudinal component. The opposite of attachment space is detachment space as the space for kinetic energy and the nonzero-energy reverse Higgs field. The combination of n units of attachment space (de-noted as 1) and n units of detachment space (denoted as 0) brings about the three digital structures: binary partition space (1)<sub>n</sub>(0)<sub>n</sub>, miscible space (1 + 0)<sub>n</sub>, and binary lattice space (1 0)<sub>n</sub> to account for quantum mechanics, special relativity, and the force fields, respectively. In the third postulate, all physical laws and phenomena are permanently reversible in the multiverse, and temporary irreversible entropy increase is allowed. Our universe is an asymmetrical dual posi-tive-energy-negative-energy universe where the positive-energy universe on attachment space absorbed the interuniversal void on detachment space to result in the combination of attachment space and detachment space, while the negative-energy universe did not absorb the interuniversal void, resulting in temporary irreversible entropy increase through reversibility breaking, sym-metry violation, and low entropy beginning. Guided by the reversible negative-energy universe, our dual universe is a globally reversible cyclic dual universe.展开更多
Emotion Model is the basis of facial expression recognition system. The constructed emotional model should not only match facial expressions with emotions, but also reflect the location relationship between different ...Emotion Model is the basis of facial expression recognition system. The constructed emotional model should not only match facial expressions with emotions, but also reflect the location relationship between different emotions. In this way, it is easy to understand the current emotion of an individual through the analysis of the acquired facial expression information. This paper constructs an improved three-dimensional model for emotion based on fuzzy theory, which corresponds to the facial features to emotions based on the basic emotions proposed by Ekman. What’s more, the three-dimensional model for motion is able to divide every emotion into three different groups which can show the positional relationship visually and quantitatively and at the same time determine the degree of emotion based on fuzzy theory.展开更多
文摘The relation between the normal displacement on the surface of a dynamical elliptical crack and the normal stress over the crack surface was studied. The three dimensional elastodynamic equations and Fourier Laplace transforms are used. Based on the influence function and the inversion of integral transforms, one can find that if the distribution of normal displacement on the surface of a dynamic elliptical crack is a polynomial of degree n in x 1 and x 2 , then the normal pressure acting over the ellipse is also a polynomial P n(x 1,x 2) of the same degree in x 1 and x 2 .
文摘For more than 60 years,Mr.Xu Yuanchong has been devoted to education.He has not only made remarkable achievements in translating from and into Chinese,English,French and other languages,but has also developed his own unique concept of translation.Since 1950,he has always adhered to the“Three Beauties Theory”,believing that translation should not only rely on the original text,but also realize the“beauty of meaning”,“beauty of sound”,and“beauty of form”.Based on Xu Yuanchong’s“Three Beauties Theory”,this paper takes Zheng Zhenduo’s and Feng Tang’s Chinese translations of Stray Birds as an example to explore in depth the specifics of poetry translation theory.The study summarizes the similarities and differences between these two translations in embodying the“three beauties”,providing insights into the Chinese translation techniques of philosophical prose poems.This endeavor seeks to offer valuable insights for the comparative study of Stray Birds translations。
基金supported by Science and Technology Young Talents Development Project of Inner Mongolia Autonomous Region(NJYT22048)NMPA Key Laboratory Open Fund Project(MDK2023025).
文摘Traditional Mongolian medicine(TMM)integrates Tibetan and Chinese medicine with indigenous Mongolian practices,focusing on the balance of three core essences:Khii,Shar,and Badgan,derived from the Five Elements-earth,water,fire,wind,and space.These essences regulate both physical and psychological processes,and their imbalance,often caused by diet,behavior,or environment,leads to disease.TMM utilizes holistic diagnostic methods such as pulse diagnosis,visual inspection,and lifestyle evaluation to identify imbalances of three essences.Treatments include herbal remedies,dietary adjustments,behavior modification,and accessory therapies like moxibustion and massage to restore balance.This mini review examines the philosophical underpinnings,diagnostic techniques,and therapeutic strategies to Khii,Shar,and Badgan,highlighting their importance in both traditional and modern integrative healthcare.
文摘BACKGROUND Extended care based on self-efficacy theory to elderly patients with intertrochanteric fractures will provide data reference to optimize the care plan of these patients,reduce patients’concurrent mental diseases,and improve prognosis.AIM To analyze the value of extended nursing based on the self-efficacy theory in older patients with intertrochanteric fractures.METHODS Older patients with intertrochanteric fractures(n=88)admitted to our hospital between January 2021 and December 2024 were randomly divided into two groups-the control group(n=44,routine nursing)and the observation group(n=44,extended nursing)-via balloting and treated for 12 weeks.The mental state,pain severity,limb function,and self-nursing ability of all patients before and after nursing were analyzed.RESULTS After nursing,the Hamilton Anxiety Scale and General Self-Efficacy Scale scores of patients in the two groups improved.Notably,Hamilton Anxiety Scale and General Self-Efficacy Scale scores in the observation group were lower and higher,respectively,than those in the control group(P<0.05).The pain severity in the observation group(2.64±0.22)was lower than that in the control group(2.85±0.41)(P<0.05).The recovery rate of limb function was higher in the observation group than in the control group(P<0.05).In addition,the self-nursing ability scores of the patients in both groups increased,with a significantly higher score in the observation group(P<0.05).CONCLUSION Extended nursing based on the self-efficacy theory can significantly improve mental state,relieve pain,and promote the recovery of limb function and self-nursing ability in older patients with intertrochanteric fractures.
文摘BACKGROUND Patients with depression following coronary heart disease often exhibit insufficient psychological resilience and self-care abilities;therefore,emphasis must be placed on nursing interventions.AIM To analyze the application value of problem-oriented education combined with nursing interventions based on the Snyder hope theory model in depressed patients after percutaneous coronary intervention(PCI).METHODS This study included 150 patients diagnosed with PCI postoperative depression because of coronary heart disease between February 2022 and February 2024.Participants were divided into two groups:A control group(n=75)receiving problem-oriented education and an observation group(n=75)receiving combined nursing interventions based on the Snyder hope theory model.Depression status,psychological resilience,self-care ability,and quality of life were compared between the two groups.RESULTS Before nursing interventions,there were no significant differences between the two groups(P>0.05).After the interventions,depression scores decreased while psychological resilience,self-care ability,and quality of life scores increased significantly in the observation group compared to that in the control group,with statistically significant differences noted(P<0.05).This combined approach can enhance psychological resilience,improve self-care abilities,and elevate the overall quality of life,warranting further promotion in clinical practice.CONCLUSION Combination of problem-oriented education and nursing interventions based on the Snyder hope theory model effectively alleviates depression in patients following PCI for coronary heart disease.
文摘This paper firstly defined the concept of folk culture block,and then analyzed the significance and planning principle of landscape design in folk culture block,and at last expounded landscape planning and design of folk culture block based on theory of three elements of landscape.
文摘Leadership is a complex process.It is one of the most researched areas around the world.It has gained importance in every walk of life from politics to business and from education to social organizations.According to the study of"Leadership in Adult Education Venues",here has a much more clear recognition of leadership:leadership is a process whereby an individual influences a group of individuals to achieve a common goal.There are many approaches of leadership throughout the study of this class,the three theories of leadership I choose to describe in this paper are:Leader-Member Exchange(LMX)Theory,Transformational Leadership,and Team Leadership.
基金Project supported by the National Natural Science Foundation of China(Nos.11272105 and 11572101)
文摘The dynamic behavior of a rectangular crack in a three-dimensional (3D) orthotropic elastic medium is investigated under a harmonic stress wave based on the non-local theory. The two-dimensional (2D) Fourier transform is applied, and the mixed- boundary value problems are converted into three pairs of dual integral equations with the unknown variables being the displacement jumps across the crack surfaces. The effects of the geometric shape of the rectangular crack, the circular frequency of the incident waves, and the lattice parameter of the orthotropic elastic medium on the dynamic stress field near the crack edges are analyzed. The present solution exhibits no stress singularity at the rectangular crack edges, and the dynamic stress field near the rectangular crack edges is finite.
基金Supported by the National Key Program of Basic Research in China (No.2004CB217702, No.2005CB221202, No.2006CB20030201) and the National Natural Science Foundation of China (No.20590367, No.50676021, No.50606006).
文摘A three-dimensional Eulerian multiphase model, with closure law according to the kinetic theory of granular flow, was used to study the gas/solid flow behaviors in spout-fluid beds. The influences of the coefficient of restitution due to non-ideal particle collisions on the simulated results were tested. It is demonstrated that the simulated result is strongly affected by the coefficient of restitution. Comparison of simulations with experiments in a small spout-fluid bed showed that an appropriate coefficient of restitution of 0.93 was necessary to simulate the flow characteristics in an underdesigned large size of spout-fluid bed coal gasifier with diameter of lm and height of 6m. The internal jet and gas/solid flow patterns at different operating conditions were obtained. The simulations show that an optimal gas/solid flow pattern for coal gasification is found when the spouting gas flow rate is equal to the fluidizing gas flow rate and the total of them is two and a half times the minimum fluidizing gas flow rate. Besides, the radial distributions of particle velocity and gas velocity show similar tendencies; the radial distributions of particle phase pressure due to particle collisions and the particle pseudo-temperature corresponding to the macroscopic kinetic energy of the random particle motion also show similar tendencies. These indicate that both gas drag force and particle collisions dominate the movement of particles.
文摘In order to meet tracking performance index of three-axis hydraulic simulator, based on classical quantitative feedback theory (QFT), an improved QFT technique is used to synthesize controller of low gain and bandwidth. By choosing a special nominal plant, the improved method assigns relative magnitude and phase tracking error between system uncertainty and nominal control plant. Relative tracking error induced by system uncertainty is transformed into sensitivity problem and relative tracking error induced by nominal plant forms into a region on Nichols chart. The two constraints further form into a combined bound which is fit for magnitude and phase loop shaping. Because of leaving out pre-filter of classical QFT controller structure, tracking performance is enhanced greatly. Furthermore, a cascaded two-loop control strategy is proposed to heighten control effect. The improved technique's efficacy is validated by simulation and experiment results.
基金financial supports from the National Natural Science Foundation of China (Grant Nos. 41571527, 41301193, 41101552,41401198)Main Direction Program (KZCX2-EW317)West Light Foundation of the Chinese Academy of Sciences (2013Yuhui)
文摘In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull" migration theory, this paper utilizes sectional data from a 2013 survey of farmers in China's Three Gorges Reservoir area to empirically analyze the factors influencing migrant workers' choice of employment location. The results indicate that 60.46% of laborers have migrated from their home province, whereas 39.54% have remained in their home province. Focusing on personal, household, and community characteristics—in addition to the economic characteristics of the sample counties—multinomial logistic regression models reveal that farmer-laborers' employment location decisions are influenced by their personal capital endowment(age, years of education and social networks), family structure(the number of laborers, elders, children and students), home village characteristics(location, economic development level and the degree of relief of the land) and home county economic development level. Notably, male and female laborers' location decisions reveal a converging trend, and their differences are not pronounced. Per capita arable land area has little influence on location decisions, whereas the educational level of laborers has a significant impact. The results differ significantly from those found in previous studies.
基金Supported by the National Natural Science Foundation of China under Grant No.50921001973 Program under Grant No. 2010CB83270
文摘Prandtl’s lifting line theory was generalized to the lifting problem of a three-dimensional hydrofoil in the presence of a free surface. Similar to the classical lifting theory, the singularity distribution method was utilized to solve two-dimensional lifting problems for the hydrofoil beneath the free surface at the air-water interface, and a lifting line theory was developed to correct three-dimensional effects of the hydrofoil with a large aspect ratio. Differing from the classical lifting theory, the main focus was on finding the three-dimensional Green function of the free surface induced by the steady motion of a system of horseshoe vortices under the free surface. Finally, numerical examples were given to show the relationship between the lift coefficient and submergence Froude numbers for 2-D and 3-D hydrofoils. If the submergence Froude number is small free surface effect will be significant registered as the increase of lift coefficient. The validity of these approaches was examined in comparison with the results calculated by other methods.
文摘it is universal acknowledgement that grammar takes an indispensable place in English learning yet increasing evidences show that there are still serious problems exists in China grammar teaching:low learning motivation,goal-oriented teaching mode and traditional deductive approach.Freeman’s Three Dimension Theory(1991)suggests that grammar should be understood as three respective:form,meaning,usage.This thesis analyses the dominant deficiencies which reveals traditional teaching mode only lays emphasis on form or meaning.Neglecting on importance of context obscures mastery of grammar rules by students.By the end of this paper,taking teaching of conditionals as examples,a suggestive teaching model is provided based on Three Dimension Theory(Freeman,1991).
基金supported by the National Natural Science Foundation of China under Grant Nos.12122401 and 12074007.
文摘In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at extremely high temperatures.However,stochastic density functional theory(SDFT)can overcome this limitation.Recently,SDFT and the related mixed stochastic–deterministic density functional theory,based on a plane-wave basis set,have been implemented in the first-principles electronic structure software ABACUS[Q.Liu and M.Chen,Phys.Rev.B 106,125132(2022)].In this study,we combine SDFT with the Born–Oppenheimer molecular dynamics method to investigate systems with temperatures ranging from a few tens of eV to 1000 eV.Importantly,we train machine-learning-based interatomic models using the SDFT data and employ these deep potential models to simulate large-scale systems with long trajectories.Subsequently,we compute and analyze the structural properties,dynamic properties,and transport coefficients of warm dense matter.
文摘Part I of this study proved that the Paraconsistent Annotated Logic using two values (PAL2v), known as the Paraquantum Logic (PQL), can represent the quantum by a model comprising two wave functions obtained from interference phenomena in the 2W (two-wave) region of Young’s experiment (double slit). With this model represented in one spatial dimension, we studied in the Lattice of the PQL, with their values represented in the set of complex numbers, the state vector of unitary module and its correspondence with the two wave functions. Based on these considerations, we applied the PQL model for obtaining Paraquantum logical states ψ related to energy levels, following the principles of the wave theory through SchrÖdinger’s equation. We also applied the probability theory and Bonferroni’s inequality for demonstrating that quantum wave functions, represented by evidence degrees, are probabilistic functions studied in the PQL Lattice, confirming that the final Paraquantum Logic Model is well suited to studies involving aspects of the wave-particle theory. This approach of quantum theory using Paraconsistent logic allows the interpretation of various phenomena of Quantum Mechanics, so it is quite promising for creating efficient models in the physical analysis and quantum computing processes.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61107053,61138001,and 61007034)the Tianjin Natural Science Foundation,China (Grant No. 11JCYBJC25900)
文摘In this study, we illustrate the effective medium theories in the designs of three-dimensional composite metama- terials of both negative permittivity and negative permeability. The proposed metamaterial consists of random coated spheres with sizes smaller compared to the wavelength embedded in a dielectric host. Simple design rules and formulas following the effective medium models are numerically and analytically presented. We demonstrate that the revised Maxwell-Garnett effective medium theory enables us to design three-dimensional composite metamaterials through the assembly of coated spheres which are random and much smaller than the wavelength of the light. The proposed ap- proach allows for the precise control of the permittivity and the permeability and guides a facile, flexible, and versatile way for the fabrication of composite metamaterials.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60601004,60801029,10876005,and60931001)
文摘This paper presents a three-dimensional time-dependent nonlinear theory of helix traveling wave tubes for beam- wave interaction. The radio frequency electromagnetic fields are represented as the superposition of azimuthally sym- metric waves in a vacuum sheath helix. Coupling impedance is introduced to the electromagnetic field equations' stimulating sources, which makes the theory easier and more flexible to realize. The space charge fields are calculated by electron beam space-charge waves expressed as the superposition solutions of Helmholtz equations. The focusing forces due to either a solenoidal field or a periodic permanent magnetic field is also included. The dynamical equations of electrons are Lorentz equations associating with electromagnetic fields, focusing fields and space-charge fields. The numerically simulated results of a tube are presented.
文摘The three postulates of the posited dynamic and reversible theory of everything are: 1) the oscil-lating M-theory postulate for the oscillating matter structure, 2) the digital transitional Higgs-reversed Higgs fields postulate for the digital space structure, and 3) the reversible multiverse post-ulate for all physical laws and phenomena. The posited theory of everything based on the three postulates explains cosmology, the composition (baryonic matter, dark matter, and dark energy) in the universe, the periodic table of elementary particles (quarks, leptons, and bosons), the galaxy evolution, superconductivity, black hole, thermodynamic, and quantum mechanics. Oscillating M-theory is derived from oscillating membrane-string-particle whose space-time dimension number oscillates between 11D and 10D and between 10D and 4D. Space-time dimension number between 10 and 4 decreases with decreasing speed of light, decreasing vacuum energy, and in-creasing rest mass. The digital transitional Higgs-reversed Higgs fields are derived from digital attachment-detachment spaces which couple to particles. Under spontaneous symmetry breaking, the coupling of massless particle to zero-energy attachment space (the space for mass) produces the transitional nonzero-energy Higgs field-particle composite which under spontaneous symmetry restoring produces massive particle on zero-energy attachment space with the longitudinal component. The opposite of attachment space is detachment space as the space for kinetic energy and the nonzero-energy reverse Higgs field. The combination of n units of attachment space (de-noted as 1) and n units of detachment space (denoted as 0) brings about the three digital structures: binary partition space (1)<sub>n</sub>(0)<sub>n</sub>, miscible space (1 + 0)<sub>n</sub>, and binary lattice space (1 0)<sub>n</sub> to account for quantum mechanics, special relativity, and the force fields, respectively. In the third postulate, all physical laws and phenomena are permanently reversible in the multiverse, and temporary irreversible entropy increase is allowed. Our universe is an asymmetrical dual posi-tive-energy-negative-energy universe where the positive-energy universe on attachment space absorbed the interuniversal void on detachment space to result in the combination of attachment space and detachment space, while the negative-energy universe did not absorb the interuniversal void, resulting in temporary irreversible entropy increase through reversibility breaking, sym-metry violation, and low entropy beginning. Guided by the reversible negative-energy universe, our dual universe is a globally reversible cyclic dual universe.
文摘Emotion Model is the basis of facial expression recognition system. The constructed emotional model should not only match facial expressions with emotions, but also reflect the location relationship between different emotions. In this way, it is easy to understand the current emotion of an individual through the analysis of the acquired facial expression information. This paper constructs an improved three-dimensional model for emotion based on fuzzy theory, which corresponds to the facial features to emotions based on the basic emotions proposed by Ekman. What’s more, the three-dimensional model for motion is able to divide every emotion into three different groups which can show the positional relationship visually and quantitatively and at the same time determine the degree of emotion based on fuzzy theory.