In this paper,the necessity of constructing a golden course for Advanced Mathematics is presented.For teachers,golden courses enhance their teaching ability and job satisfaction.For students,golden courses improve the...In this paper,the necessity of constructing a golden course for Advanced Mathematics is presented.For teachers,golden courses enhance their teaching ability and job satisfaction.For students,golden courses improve their sense of learning value and significance and encourage them to actively learn and participate deeply.Next,the relevant content of course ideological and political construction is provided.Finally,a specific approach was proposed to create a golden course for Advanced Mathematics by integrating ideological and political education into the curriculum.展开更多
By dint of the stability of Cauchy-type integral with kernel density of class H＊ for an open arc, this paper discusses the stability of the solution of Riemann boundary value problem with respect to the perturbation ...By dint of the stability of Cauchy-type integral with kernel density of class H＊ for an open arc, this paper discusses the stability of the solution of Riemann boundary value problem with respect to the perturbation of boundary curve to be an open arc.展开更多
In this article, by using the stability of Cauchy type integral when the smooth perturbation for integral curve and the Sobolev type perturbation for kernel density happen, we discuss the stability of the second funda...In this article, by using the stability of Cauchy type integral when the smooth perturbation for integral curve and the Sobolev type perturbation for kernel density happen, we discuss the stability of the second fundamental problem in plane elasticity when the smooth perturbation for the boundary of the elastic domain （unit disk） and the Sobolev type perturbation for the displacement happen. And the error estimate of the displacement between the second fundamental problem and its perturbed problem is obtained.展开更多
A labeling of a graph G is a bijection from E（G） to the set {1,2,…,｜E （G）｜ }.A labeling is antimagic if for any distinct vertices x and y,the sum of the labels on edges incident to x is different from the sum o...A labeling of a graph G is a bijection from E（G） to the set {1,2,…,｜E （G）｜ }.A labeling is antimagic if for any distinct vertices x and y,the sum of the labels on edges incident to x is different from the sum of the labels on edges incident to y.We say that a graph is antimagic if it has an antimagic labeling.Hartsfield and Ringel conjectured in 1990 that every graph other than 2 K is antimagic.In this paper,we show that the antimagic conjecture is false for the case of disconnected graphs.Furthermore,we find some classes of disconnected graphs that are antimagic and some classes of graphs whose complement are disconnected are antimagic.展开更多
The density functional theory（DFT） and self-consistent periodic calculation were used to investigate the methanol adsorption on the Pt-Mo（111）/C surface.The adsorption energies,equilibrium geometries and vibration...The density functional theory（DFT） and self-consistent periodic calculation were used to investigate the methanol adsorption on the Pt-Mo（111）/C surface.The adsorption energies,equilibrium geometries and vibration frequencies of CH3OH on nine types of sites on the Pt-Mo（111）/C surface were predicted and the favorite adsorption site for methanol is the top-Pt site.Both sites of valence and conduction bands of doped system have been broadened,which are favorable for electrons to transfer to the cavity.The possible decomposition pathway was investigated with transition state searching and the calculation results indicate that the O-H bond is first broken,and then the methanol decomposes into methoxy.The activation barrier of O-H bond breaking with Pt-Mo catalyst is only 104.8 kJ mol-1,showing that carbon supported Pt-Mo alloys have promoted the decomposition of methanol.Comparing with the adsorption energies of CH3OH on the Pt（111）/C surface and that of CO,the adsorption energies of CO are higher,and Pt（111）/C is liable to be oxidized and loses the activity,which suggests that the catalyst Pt-Mo（111）/C is in favor of decomposing methanol and has better anti-poisoning ability than Pt（111）/C.展开更多
A labelingfof a graph G is a bijection from its edge set E（G） to the set {1,2,...,｜E（G）｜}, which is antimagic if for any distinct vertices x and y, the sum of the labels on edges incident to x is different from ...A labelingfof a graph G is a bijection from its edge set E（G） to the set {1,2,...,｜E（G）｜}, which is antimagic if for any distinct vertices x and y, the sum of the labels on edges incident to x is different from the sum of the labels on edges incident to y. A graph G is antimagic if G has anfwhich is antimagic. Hartsfield and Ringel conjectured in 1990 that every connected graph other than K2 is antimagic. In this paper, we show that if G1 is an m-vertex graph with maximum degree at most 6r＋ 1, and G2 is an n-vertex （2r）-regular graph （m≥n≥3）, then the join graph G1 v G2 is antimagic.展开更多
Diamond films are deposited on Mo substrates by dc hot-cathode plasma chemical vapor deposition method using a CH4-H2-CO2 gas mixture. Adjusting the flow of CO2, we study the relevant influence on surface morphology, ...Diamond films are deposited on Mo substrates by dc hot-cathode plasma chemical vapor deposition method using a CH4-H2-CO2 gas mixture. Adjusting the flow of CO2, we study the relevant influence on surface morphology, grain orientation and crystalline quality of films with scanning electron microscopy, x-ray diffraction, Raman spectroscopy, respectively. The results show that grain orientation of the films has a transition with the increasing CO2 addition, from （100） orientation to （110） orientation and then （111） orientation. The crystalline quality is improved but the growth rate is decreased by raising the flow of CO2. The experimental results are also discussed briefly.展开更多
An H-covering(resp.decomposition) of a graph G is a set of subgraphs of G,{H1,H2,…,Hk} such that H1 is isomorphic to H for eachi,and each edge of G belongs to at least(resp.exactly) one of the subgraphs Hi,fox 1≤i≤...An H-covering(resp.decomposition) of a graph G is a set of subgraphs of G,{H1,H2,…,Hk} such that H1 is isomorphic to H for eachi,and each edge of G belongs to at least(resp.exactly) one of the subgraphs Hi,fox 1≤i≤k.An H-covering(resp.decomposition) of a graph G is a magic H-covering(resp.decomposition) if there is a bijection f:V(G)∪E(G)→{1,...,|V(G)|+|E(G)|} such that the sum of labels of edges and the vertices of each copy of H in the decomposition is a constant.If G admits a unique H-covering H and H is a magic H-covering of G,then G is H-magic.In this paper,we show that if G admits a magic H-covering(resp.decomposition),and satisfies some other conditions,then a union of k vertex joint graph G,kG,and a graph obtained from kG,Gk admit a magic H-covering or decomposition.展开更多
This paper discusses the stability of the welding problems under different materials with same shearing modulus. Using the stability of Cauchy type integral while the smooth perturbation for the integral curve and Sob...This paper discusses the stability of the welding problems under different materials with same shearing modulus. Using the stability of Cauchy type integral while the smooth perturbation for the integral curve and Sobolev perturbation for the kernel density happening, the stability of complex stress functions are studied and errors of stress and displacement are given.展开更多
In this article, we investigate the density of the solution to a class of stochastic functional differential equations by means of Malliavin calculus. Our aim is to provide upper and lower Gaussian estimates for the d...In this article, we investigate the density of the solution to a class of stochastic functional differential equations by means of Malliavin calculus. Our aim is to provide upper and lower Gaussian estimates for the density.展开更多
From Bethe-Salpeter equation,we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson.This equation is applied to investigate the exotic narrow state X (3872) assumed ...From Bethe-Salpeter equation,we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson.This equation is applied to investigate the exotic narrow state X (3872) assumed as a molecule state composed of D 0 0.The contribution of the resonance 0 is the attractive interaction between two heavy mesons in this molecule state.The calculated mass of X is consistent with the experimental data.展开更多
A methodology for identifying and calibrating the material parameters for a coupled hydro-mechanical problem is presented in this pape r.For validation purpose,a laboratory-based water infiltration test was numericall...A methodology for identifying and calibrating the material parameters for a coupled hydro-mechanical problem is presented in this pape r.For validation purpose,a laboratory-based water infiltration test was numerically simulated using finite element method(FEM).The test was conducted using a self-designed column-type experimental device,which mimicked the wetting process of a candidate backfill material in a nuclear waste repository.The real-time measurements of key state variables(e.g.water content,relative humidity,temperature,and total stresses)were performed with the monitoring sensors along the height of cylindrical soil sample.For numerical simulation,the modified Barcelona Basic Model(BBM)along with soil-water retention model for compacted bentonite was used.It shows that the identified model parameters successfully captured the moisture migration process under an applied hydraulic gradient in a bentonite-based compacted soil sample.A comparison between the measured and predicted values of total stresses both in axial and lateral directions along with other state variables revealed that heterogeneous moisture content was distributed along the hydration-path,resulting in non-uniform stress-deformation characteristics of soil.展开更多
The compressibility, the temperature dependence of bulk modulus, the pressure dependence of normalized volume V/V0, thermal expansion coefficient and Debye temperature of LaNi5-xAlx compounds are successfully obtained...The compressibility, the temperature dependence of bulk modulus, the pressure dependence of normalized volume V/V0, thermal expansion coefficient and Debye temperature of LaNi5-xAlx compounds are successfully obtained using the first-principles plane-wave pseudopotential （PW-PP） method, the EOSFIT6.0 software and the quasiharmonic Debye model. The rapid decrease of relative lattice constant a/a0 shows that the deformation is easier in directions normal to the c-axis than that along it. The relationships between bulk modulus B and pressure at different temperatures are also analysed. It is found that the bulk modulus B increases monotonically with increasing pressure. Moreover, the pressure dependences of thermal expansion and Debye temperature are also successfully obtained. The calculated results are in agreement with the experimental data.展开更多
The authors examine the relation between the perturbed Cauchy singular integral with its kernel density belong to H＊ and unperturbed one and show that the Cauchy singular integral is stable under perturbation of the ...The authors examine the relation between the perturbed Cauchy singular integral with its kernel density belong to H＊ and unperturbed one and show that the Cauchy singular integral is stable under perturbation of the curve of integration.展开更多
This paper presents a new kind of CVD diamond graver for stone machining. Taking granite as machining object,we studied influence of cutting speed,feed rate and depth of cut on tool life by means of variance analysis ...This paper presents a new kind of CVD diamond graver for stone machining. Taking granite as machining object,we studied influence of cutting speed,feed rate and depth of cut on tool life by means of variance analysis and regression analysis. The result indicated that cutting speed had a more remarkable effect on tool life; feed rate ranked the second; depth of cut had no significant influence on tool life. Scanning electron microscope (SEM) was used to observe wear morphologies of gravers. It was found that abrasive wear was the main wear mechanism.展开更多
An investigation on the structural stabilities and electronic properties of SrX （X =S, Se and Te） under high pressure is conducted using the first-principles calculation based on density functional theory （DFT） wi...An investigation on the structural stabilities and electronic properties of SrX （X =S, Se and Te） under high pressure is conducted using the first-principles calculation based on density functional theory （DFT） with the plane wave basis set as implemented in the CASTEP code. Our results demonstrate that the sequence of the pressure-induced phase transition of the three compounds is the NaCl-type （B1） structure （Fm3rn） to the CsC1- type （B2） structure （Pm3m）. The phase transition and the metallization pressures are determined theoretically. The pressure effect on the optical properties is discussed. The results are compared with the previous calculations and experimental data.展开更多
Real estate is the ＂barometer＂ of the national economy, this paper studies the formation of the current domestic real estate prices and the inner mechanism of the influence factors, using the principal component ana...Real estate is the ＂barometer＂ of the national economy, this paper studies the formation of the current domestic real estate prices and the inner mechanism of the influence factors, using the principal component analysis to determine the composition of the real estate market development index model, and the BP neural network model is established, with specific data analysis which verifies the correctness and practicability of the model.展开更多
Based on the good localization characteristic of the wavelet transform both in time and frequency domain, a de-noising method based on wavelet transform is presented, which can make the extraction of visual evoked pot...Based on the good localization characteristic of the wavelet transform both in time and frequency domain, a de-noising method based on wavelet transform is presented, which can make the extraction of visual evoked potentials in single training sample from the EEG background noise in favor of studying the changes between the single sample response happen. The information is probably related with the different function, appearance and pathologies of the brain. At the same time this method can also be used to remove those signal’s artifacts that do not appear with EP within the same scope of time or frequency. The traditional Fourier filter can hardly attain the similar result. This method is different from other wavelet de-noising methods in which different criteria are employed in choosing wavelet coefficient. It has a biggest virtue of noting the differences among the single training sample and making use of the characteristics of high time frequency resolution to reduce the effect of interference factors to a maximum extent within the time scope that EP appear. The experiment result proves that this method is not restricted by the signal-to-noise ratio of evoked potential and electroencephalograph (EEG) and even can recognize instantaneous event under the condition of lower signal-to-noise ratio, as well as recognize the samples which evoked evident response more easily. Therefore, more evident average evoked response could be achieved by de-nosing the signals obtained through averaging out the samples that can evoke evident responses than de-nosing the average of original signals. In addition, averaging methodology can dramatically reduce the number of record samples needed, thus avoiding the effect of behavior change during the recording process. This methodology pays attention to the differences among single training sample and also accomplishes the extraction of visual evoked potentials from single trainings sample. As a result, system speed and accuracy could be improved to a great extent if this methodology is applied to brain-computer interface system based on evoked responses.展开更多
Dependence of bulk modulus on both pressure and temperature, the elastic constants Cij and the pressure and temperature dependence of normalized volume V/Vo of cubic Ni2MnGa alloy are successfully obtained using the f...Dependence of bulk modulus on both pressure and temperature, the elastic constants Cij and the pressure and temperature dependence of normalized volume V/Vo of cubic Ni2MnGa alloy are successfully obtained using the first-principles plane-wave pseudopotential （PW-PP） method as well as the quasi-harmonic Debye model. We analyse the relationship between bulk modulus and temperature up to 800 K and obtain the relationships between bulk modulus B and pressures at different temperatures. It is found that the bulk modulus B increases monotonically with increasing pressure. Moreover, the temperature dependences of the Debye temperature are also analysed. The calculated results are in agreement with the available experimental data and the previous theoreticM results.展开更多
基金Project of Heilongjiang University of Finance and Economics(XJYB2024056)Project of Heilongjiang University of Finance and Economics(XJYB2024057)。
文摘In this paper,the necessity of constructing a golden course for Advanced Mathematics is presented.For teachers,golden courses enhance their teaching ability and job satisfaction.For students,golden courses improve their sense of learning value and significance and encourage them to actively learn and participate deeply.Next,the relevant content of course ideological and political construction is provided.Finally,a specific approach was proposed to create a golden course for Advanced Mathematics by integrating ideological and political education into the curriculum.
基金supported by Natural Science Foundation of China (10071016)the Natural Science Foundation of Fujian Province (2008J0187)the Science and Technology Foundation of Education Department of Fujian Province (JA08255), China
文摘By dint of the stability of Cauchy-type integral with kernel density of class H＊ for an open arc, this paper discusses the stability of the solution of Riemann boundary value problem with respect to the perturbation of boundary curve to be an open arc.
基金supported by NNSF of China(11171260)RFDP of Higher Education of China(20100141110054)+3 种基金NSF of Fujian ProvinceChina(2008J0187)STF of Education Department of Fujian ProvinceChina(JA11341)
文摘In this article, by using the stability of Cauchy type integral when the smooth perturbation for integral curve and the Sobolev type perturbation for kernel density happen, we discuss the stability of the second fundamental problem in plane elasticity when the smooth perturbation for the boundary of the elastic domain （unit disk） and the Sobolev type perturbation for the displacement happen. And the error estimate of the displacement between the second fundamental problem and its perturbed problem is obtained.
基金Supported by the National Natural Science Foundation of China (10201022,10971144,and 11101020)the Natural Science Foundation of Beijing (1102015)the Fundamental Research Funds for the Central Universities(2011B019)
文摘A labeling of a graph G is a bijection from E（G） to the set {1,2,…,｜E （G）｜ }.A labeling is antimagic if for any distinct vertices x and y,the sum of the labels on edges incident to x is different from the sum of the labels on edges incident to y.We say that a graph is antimagic if it has an antimagic labeling.Hartsfield and Ringel conjectured in 1990 that every graph other than 2 K is antimagic.In this paper,we show that the antimagic conjecture is false for the case of disconnected graphs.Furthermore,we find some classes of disconnected graphs that are antimagic and some classes of graphs whose complement are disconnected are antimagic.
文摘The density functional theory（DFT） and self-consistent periodic calculation were used to investigate the methanol adsorption on the Pt-Mo（111）/C surface.The adsorption energies,equilibrium geometries and vibration frequencies of CH3OH on nine types of sites on the Pt-Mo（111）/C surface were predicted and the favorite adsorption site for methanol is the top-Pt site.Both sites of valence and conduction bands of doped system have been broadened,which are favorable for electrons to transfer to the cavity.The possible decomposition pathway was investigated with transition state searching and the calculation results indicate that the O-H bond is first broken,and then the methanol decomposes into methoxy.The activation barrier of O-H bond breaking with Pt-Mo catalyst is only 104.8 kJ mol-1,showing that carbon supported Pt-Mo alloys have promoted the decomposition of methanol.Comparing with the adsorption energies of CH3OH on the Pt（111）/C surface and that of CO,the adsorption energies of CO are higher,and Pt（111）/C is liable to be oxidized and loses the activity,which suggests that the catalyst Pt-Mo（111）/C is in favor of decomposing methanol and has better anti-poisoning ability than Pt（111）/C.
基金Supported by the National Natural Science Foundation of China(11371052,11271267,10971144,11101020)the Natural Science Foundation of Beijing(1102015)the Fundamental Research Funds for the Central Univer sities(2011B019,3142013104)
文摘A labelingfof a graph G is a bijection from its edge set E（G） to the set {1,2,...,｜E（G）｜}, which is antimagic if for any distinct vertices x and y, the sum of the labels on edges incident to x is different from the sum of the labels on edges incident to y. A graph G is antimagic if G has anfwhich is antimagic. Hartsfield and Ringel conjectured in 1990 that every connected graph other than K2 is antimagic. In this paper, we show that if G1 is an m-vertex graph with maximum degree at most 6r＋ 1, and G2 is an n-vertex （2r）-regular graph （m≥n≥3）, then the join graph G1 v G2 is antimagic.
文摘Diamond films are deposited on Mo substrates by dc hot-cathode plasma chemical vapor deposition method using a CH4-H2-CO2 gas mixture. Adjusting the flow of CO2, we study the relevant influence on surface morphology, grain orientation and crystalline quality of films with scanning electron microscopy, x-ray diffraction, Raman spectroscopy, respectively. The results show that grain orientation of the films has a transition with the increasing CO2 addition, from （100） orientation to （110） orientation and then （111） orientation. The crystalline quality is improved but the growth rate is decreased by raising the flow of CO2. The experimental results are also discussed briefly.
基金Supported by the National Natural Science Foundation of China(11702094)the Fundamental Research Funds for the Central Universities(3142015043)North China Institute of Science and Technology Applied Mathematics Innovation Team(3142018059)。
文摘An H-covering(resp.decomposition) of a graph G is a set of subgraphs of G,{H1,H2,…,Hk} such that H1 is isomorphic to H for eachi,and each edge of G belongs to at least(resp.exactly) one of the subgraphs Hi,fox 1≤i≤k.An H-covering(resp.decomposition) of a graph G is a magic H-covering(resp.decomposition) if there is a bijection f:V(G)∪E(G)→{1,...,|V(G)|+|E(G)|} such that the sum of labels of edges and the vertices of each copy of H in the decomposition is a constant.If G admits a unique H-covering H and H is a magic H-covering of G,then G is H-magic.In this paper,we show that if G admits a magic H-covering(resp.decomposition),and satisfies some other conditions,then a union of k vertex joint graph G,kG,and a graph obtained from kG,Gk admit a magic H-covering or decomposition.
基金Supported by the National Natural Science Foundation of China(11171260)Science and Technology Foundation of Education Department of Fujian Province(JA11341)
文摘This paper discusses the stability of the welding problems under different materials with same shearing modulus. Using the stability of Cauchy type integral while the smooth perturbation for the integral curve and Sobolev perturbation for the kernel density happening, the stability of complex stress functions are studied and errors of stress and displacement are given.
基金supported by Viet Nam National Foundation for Science and Technology Development(NAFOSTED) under grant number 101.03-2015.15supported by the Vietnam National University,Hanoi(QG.16.09)
文摘In this article, we investigate the density of the solution to a class of stochastic functional differential equations by means of Malliavin calculus. Our aim is to provide upper and lower Gaussian estimates for the density.
文摘From Bethe-Salpeter equation,we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson.This equation is applied to investigate the exotic narrow state X (3872) assumed as a molecule state composed of D 0 0.The contribution of the resonance 0 is the attractive interaction between two heavy mesons in this molecule state.The calculated mass of X is consistent with the experimental data.
基金the German Research Foundation(DFG)for the financial support(Grant No.SCHA 675/17-1)。
文摘A methodology for identifying and calibrating the material parameters for a coupled hydro-mechanical problem is presented in this pape r.For validation purpose,a laboratory-based water infiltration test was numerically simulated using finite element method(FEM).The test was conducted using a self-designed column-type experimental device,which mimicked the wetting process of a candidate backfill material in a nuclear waste repository.The real-time measurements of key state variables(e.g.water content,relative humidity,temperature,and total stresses)were performed with the monitoring sensors along the height of cylindrical soil sample.For numerical simulation,the modified Barcelona Basic Model(BBM)along with soil-water retention model for compacted bentonite was used.It shows that the identified model parameters successfully captured the moisture migration process under an applied hydraulic gradient in a bentonite-based compacted soil sample.A comparison between the measured and predicted values of total stresses both in axial and lateral directions along with other state variables revealed that heterogeneous moisture content was distributed along the hydration-path,resulting in non-uniform stress-deformation characteristics of soil.
基金Supported by the National Natural Science Foundation of China under Grant No 60777012 and the Programme for Science and Technology Innovation Talents in Universities of Henan Province under Grant No 2008HASTIT008
文摘The compressibility, the temperature dependence of bulk modulus, the pressure dependence of normalized volume V/V0, thermal expansion coefficient and Debye temperature of LaNi5-xAlx compounds are successfully obtained using the first-principles plane-wave pseudopotential （PW-PP） method, the EOSFIT6.0 software and the quasiharmonic Debye model. The rapid decrease of relative lattice constant a/a0 shows that the deformation is easier in directions normal to the c-axis than that along it. The relationships between bulk modulus B and pressure at different temperatures are also analysed. It is found that the bulk modulus B increases monotonically with increasing pressure. Moreover, the pressure dependences of thermal expansion and Debye temperature are also successfully obtained. The calculated results are in agreement with the experimental data.
基金Supported by the Natural Science Foundation of Fujian Province（2008J0187）
文摘The authors examine the relation between the perturbed Cauchy singular integral with its kernel density belong to H＊ and unperturbed one and show that the Cauchy singular integral is stable under perturbation of the curve of integration.
基金supported by Jilin Science and Technology Development Plan Project(20070314)
文摘This paper presents a new kind of CVD diamond graver for stone machining. Taking granite as machining object,we studied influence of cutting speed,feed rate and depth of cut on tool life by means of variance analysis and regression analysis. The result indicated that cutting speed had a more remarkable effect on tool life; feed rate ranked the second; depth of cut had no significant influence on tool life. Scanning electron microscope (SEM) was used to observe wear morphologies of gravers. It was found that abrasive wear was the main wear mechanism.
基金Supported by the National Natural Science Foundation of China under Grant Nos 40473034, 40404007, 10574055 and 50532020, and the National Basic Research Programme of China under Grant No 2005CB724404.
文摘An investigation on the structural stabilities and electronic properties of SrX （X =S, Se and Te） under high pressure is conducted using the first-principles calculation based on density functional theory （DFT） with the plane wave basis set as implemented in the CASTEP code. Our results demonstrate that the sequence of the pressure-induced phase transition of the three compounds is the NaCl-type （B1） structure （Fm3rn） to the CsC1- type （B2） structure （Pm3m）. The phase transition and the metallization pressures are determined theoretically. The pressure effect on the optical properties is discussed. The results are compared with the previous calculations and experimental data.
文摘Real estate is the ＂barometer＂ of the national economy, this paper studies the formation of the current domestic real estate prices and the inner mechanism of the influence factors, using the principal component analysis to determine the composition of the real estate market development index model, and the BP neural network model is established, with specific data analysis which verifies the correctness and practicability of the model.
文摘Based on the good localization characteristic of the wavelet transform both in time and frequency domain, a de-noising method based on wavelet transform is presented, which can make the extraction of visual evoked potentials in single training sample from the EEG background noise in favor of studying the changes between the single sample response happen. The information is probably related with the different function, appearance and pathologies of the brain. At the same time this method can also be used to remove those signal’s artifacts that do not appear with EP within the same scope of time or frequency. The traditional Fourier filter can hardly attain the similar result. This method is different from other wavelet de-noising methods in which different criteria are employed in choosing wavelet coefficient. It has a biggest virtue of noting the differences among the single training sample and making use of the characteristics of high time frequency resolution to reduce the effect of interference factors to a maximum extent within the time scope that EP appear. The experiment result proves that this method is not restricted by the signal-to-noise ratio of evoked potential and electroencephalograph (EEG) and even can recognize instantaneous event under the condition of lower signal-to-noise ratio, as well as recognize the samples which evoked evident response more easily. Therefore, more evident average evoked response could be achieved by de-nosing the signals obtained through averaging out the samples that can evoke evident responses than de-nosing the average of original signals. In addition, averaging methodology can dramatically reduce the number of record samples needed, thus avoiding the effect of behavior change during the recording process. This methodology pays attention to the differences among single training sample and also accomplishes the extraction of visual evoked potentials from single trainings sample. As a result, system speed and accuracy could be improved to a great extent if this methodology is applied to brain-computer interface system based on evoked responses.
基金Supported by the National Natural Science Foundation of China under Grant No 60777012, and the Programme for Science and Technology Innovation Talents in Universities of Henan Province under Grant No 2008HASTIT008.
文摘Dependence of bulk modulus on both pressure and temperature, the elastic constants Cij and the pressure and temperature dependence of normalized volume V/Vo of cubic Ni2MnGa alloy are successfully obtained using the first-principles plane-wave pseudopotential （PW-PP） method as well as the quasi-harmonic Debye model. We analyse the relationship between bulk modulus and temperature up to 800 K and obtain the relationships between bulk modulus B and pressures at different temperatures. It is found that the bulk modulus B increases monotonically with increasing pressure. Moreover, the temperature dependences of the Debye temperature are also analysed. The calculated results are in agreement with the available experimental data and the previous theoreticM results.
基金Projects(52204363,12004169)supported by the National Natural Science Foundation of ChinaProject(22C0220)supported by the Education Department of Hunan Province,China。
