With the rapid integration of renewable energy,wide-band oscillations caused by interactions between power electronic equipment and grids have emerged as one of the most critical stability issues.Existing methods are ...With the rapid integration of renewable energy,wide-band oscillations caused by interactions between power electronic equipment and grids have emerged as one of the most critical stability issues.Existing methods are usually studied for local power systems with around one hundred nodes.However,for a large-scale power system with tens of thousands of nodes,the dimension of transfer function matrix or the order of characteristic equation is much higher.In this case,the existing methods such as eigenvalue analysis method and impedance-based method have difficulty in computation and are thus hard to utilize in practice.To fill this gap,this paper proposes a novel method named the smallest eigenvalues based logarithmic derivative(SELD)method.It obtains the dominant oscillation modes by the logarithmic derivative of the k-smallest eigenvalue curves of the sparse extended nodal admittance matrix(NAM).An oscillatory stability analysis tool is further developed based on this method.The effectiveness of the method and the tool is validated through a local power system as well as a large-scale power system.展开更多
Hirota method is applied to solve the modified nonlinear Schrodinger equation/the derivative nonlinear Schrodinger equation(MNLSE/DNLSE) under nonvanishing boundary conditions(NVBC) and lead to a single and double-pol...Hirota method is applied to solve the modified nonlinear Schrodinger equation/the derivative nonlinear Schrodinger equation(MNLSE/DNLSE) under nonvanishing boundary conditions(NVBC) and lead to a single and double-pole soliton solution in an explicit form. The general procedures of Hirota method are presented, as well as the limit approach of constructing a soliton-antisoliton pair of equal amplitude with a particular chirp. The evolution figures of these soliton solutions are displayed and analyzed. The influence of the perturbation term and background oscillation strength upon the DPS is also discussed.展开更多
In this paper, a new derivative free trust region method is developed based on the conic interpolation model for the unconstrained optimization. The conic interpolation model is built by means of the quadratic model f...In this paper, a new derivative free trust region method is developed based on the conic interpolation model for the unconstrained optimization. The conic interpolation model is built by means of the quadratic model function, the collinear scaling formula, quadratic approximation and interpolation. All the parameters in this model are determined by objective function interpolation condition. A new derivative free method is developed based upon this model and the global convergence of this new method is proved without any information on gradient.展开更多
a-Oxo ketene dithioacetals 2 via 1,2-nucleophilie addition by methallyl magnesius chloride afforded corresponding alcohols (3). Treated with water or methanol and catalyzed by Lewis acid, the alcohols 3 were converted...a-Oxo ketene dithioacetals 2 via 1,2-nucleophilie addition by methallyl magnesius chloride afforded corresponding alcohols (3). Treated with water or methanol and catalyzed by Lewis acid, the alcohols 3 were converted regiospecifical ly to substituted phenols 5' or related phenol methyl ethers 5 respectively. This reaction is a novel approach to the synthesis of phenols and their derivatives starting from non-aromatic precursors.展开更多
The state of Tb3+ is investigated in liposome. When the concentration of PC is below CMC (critical micell concentration), most of Tb3+ is associated with PC, the binding constant is about 3.35×103 L/mol. When the...The state of Tb3+ is investigated in liposome. When the concentration of PC is below CMC (critical micell concentration), most of Tb3+ is associated with PC, the binding constant is about 3.35×103 L/mol. When the concentration of PC is beyond CMC, most of Tb3+ is dimerized, the dimerization constant is about 3.92×104L/mol. In PC?CH?H2O system, the binding constant of Tb3+?CH complex 2.93×104L/mol is obtained.展开更多
Applying the parametric derivation method, Peierls energy and Peierls stress are calculated with a non-sinusoidal force law in the lattice theory, while the results obtained by the power-series expansion according to ...Applying the parametric derivation method, Peierls energy and Peierls stress are calculated with a non-sinusoidal force law in the lattice theory, while the results obtained by the power-series expansion according to sinusoidal law can be deduced as a limiting case of non- sinusoidal law. The simplified expressions of Peierls energy and Peierls stress are obtained for the limit of wide and narrow. Peierls energy and Peierls stress decrease monotonically with the factor of modification of force law. Present results can be used expediently for prediction of the correct order of magnitude of Peierls stress for materials.展开更多
This research was aim to develop novel cyclodextrin/chitosan （CD/CS） nanocarriers for insoluble drug delivery through the mild ionic gelation method previously developed by our lab. A series of different β- cyclode...This research was aim to develop novel cyclodextrin/chitosan （CD/CS） nanocarriers for insoluble drug delivery through the mild ionic gelation method previously developed by our lab. A series of different β- cyclodextrin （β-CD） derivatives were incorporated into CS nanoparticles including hydroxypropyl-β- cyclodextrin （HP-β-CD）, sulphobutylether-β-cyclodextrin （SB-β-CD）, and 2,6-di-O-methy-βcyclodex- trin （DM-β-CD）. Various process parameters for nanoparticle preparation and their effects on physicochemical properties of CD/CS nanoparticles were investigated, such as the type of CD derivatives, CD and CS concentrations, the mass ratio of CS to TPP （CS/TRP）, and pH values. In the optimal condition, CDICS nanoparticles were obtained in the size range of 215-276 nm and with the zeta potential from 30.22 mV to 35.79 mY. Moreover, the stability study showed that the incorporation of CD rendered the CD/CS nanocarriers more stable than CS nanoparticles in PBS buffer at pH 6.8. For their easy preparation and adjustable parameters in nanoparticle formation as well as the diversified hydrophobic core of CD derivatives, the novel CD/CS nanoparticles developed herein might represent an interesting and versatile drug delivery platform for a variety of poorly water-soluble drugs with different physicochemical properties.展开更多
The stochastic bifurcation of a generalized Duffing–van der Pol system with fractional derivative under color noise excitation is studied. Firstly, fractional derivative in a form of generalized integral with time-de...The stochastic bifurcation of a generalized Duffing–van der Pol system with fractional derivative under color noise excitation is studied. Firstly, fractional derivative in a form of generalized integral with time-delay is approximated by a set of periodic functions. Based on this work, the stochastic averaging method is applied to obtain the FPK equation and the stationary probability density of the amplitude. After that, the critical parameter conditions of stochastic P-bifurcation are obtained based on the singularity theory. Different types of stationary probability densities of the amplitude are also obtained. The study finds that the change of noise intensity, fractional order, and correlation time will lead to the stochastic bifurcation.展开更多
Regarding the rapid compensation of the influence of the Earth＇ s disturbing gravity field upon trajectory calculation,the key point lies in how to derive the analytical solutions to the partial derivatives of the st...Regarding the rapid compensation of the influence of the Earth＇ s disturbing gravity field upon trajectory calculation,the key point lies in how to derive the analytical solutions to the partial derivatives of the state of burnout point with respect to the launch data.In view of this,this paper mainly expounds on two issues：one is based on the approximate analytical solution to the motion equation for the vacuum flight section of a long-range rocket,deriving the analytical solutions to the partial derivatives of the state of burnout point with respect to the changing rate of the finalstage pitch program;the other is based on the initial positioning and orientation error propagation mechanism,proposing the analytical calculation formula for the partial derivatives of the state of burnout point with respect to the launch azimuth.The calculation results of correction data are simulated and verified under different circumstances.The simulation results are as follows：（1） the accuracy of approximation between the analytical solutions and the results attained via the difference method is higher than 90%,and the ratio of calculation time between them is lower than 0.2%,thus demonstrating the accuracy of calculation of data corrections and advantages in calculation speed;（2） after the analytical solutions are compensated,the longitudinal landing deviation of the rocket is less than 20 m and the lateral landing deviation of the rocket is less than 10 m,demonstrating that the corrected data can meet the requirements for the hit accuracy of a long-range rocket.展开更多
In this paper,we propose a numerical method to estimate the unknown order of a Riemann-Liouville fractional derivative for a fractional Stokes＇ first problem for a heated generalized second grade fluid.The implicit n...In this paper,we propose a numerical method to estimate the unknown order of a Riemann-Liouville fractional derivative for a fractional Stokes＇ first problem for a heated generalized second grade fluid.The implicit numerical method is employed to solve the direct problem.For the inverse problem,we first obtain the fractional sensitivity equation by means of the digamma function,and then we propose an efficient numerical method,that is,the Levenberg-Marquardt algorithm based on a fractional derivative,to estimate the unknown order of a Riemann-Liouville fractional derivative.In order to demonstrate the effectiveness of the proposed numerical method,two cases in which the measurement values contain random measurement error or not are considered.The computational results demonstrate that the proposed numerical method could efficiently obtain the optimal estimation of the unknown order of a RiemannLiouville fractional derivative for a fractional Stokes＇ first problem for a heated generalized second grade fluid.展开更多
The variational iteration method is successfully extended to the case of solving fractional differential equations, and the Lagrange multiplier of the method is identified in a more accurate way. Some diffusion models...The variational iteration method is successfully extended to the case of solving fractional differential equations, and the Lagrange multiplier of the method is identified in a more accurate way. Some diffusion models with fractional derivatives are investigated analytically, and the results show the efficiency of the new Lagrange multiplier for fractional differential equations of arbitrary order.展开更多
The treatment of advective fluxes in high-order finite volume models is well established, but this is not the case for diffusive fluxes, due to the conflict between the discontinuous representation of the solution and...The treatment of advective fluxes in high-order finite volume models is well established, but this is not the case for diffusive fluxes, due to the conflict between the discontinuous representation of the solution and the continuous structure of analytic solutions. In this paper, a derivative reconstruction approach is proposed in the context of spectral volume methods, for the approximation of diffusive fluxes, aiming at the reconciliation of this conflict. Two different reconstructions are used for advective and diffusive fluxes： the advective reconstruction makes use of the information contained in a spectral cell, and allows the formation of discontinuities at the spectral cells boundaries; the diffusive reconstruction makes use of the information contained in contiguous spectral cells, imposing the continuity of the reconstruction at the spectral cells boundaries. The method is demonstrated by a number of numerical experiments, including the solution of shallow-water equations, complemented with the advective-diffusive transport equation of a conservative substance, showing the promising abilities of the numerical scheme proposed.展开更多
We introduce conformable fractional Nikiforov–Uvarov(NU) method by means of conformable fractional derivative which is the most natural definition in non-integer calculus. Since, NU method gives exact eigenstate solu...We introduce conformable fractional Nikiforov–Uvarov(NU) method by means of conformable fractional derivative which is the most natural definition in non-integer calculus. Since, NU method gives exact eigenstate solutions of Schr¨odinger equation(SE) for certain potentials in quantum mechanics, this method is carried into the domain of fractional calculus to obtain the solutions of fractional SE. In order to demonstrate the applicability of the conformable fractional NU method, we solve fractional SE for harmonic oscillator potential, Woods–Saxon potential, and Hulthen potential.展开更多
One of the evolving hand biometric features considered so far is finger knuckle printing,because of its ability towards unique identification of individuals.Despite many attempts have been made in this area of researc...One of the evolving hand biometric features considered so far is finger knuckle printing,because of its ability towards unique identification of individuals.Despite many attempts have been made in this area of research,the accuracy of the recognition model remains a major issue.To overcome this problem,a novel biometric-based method,named fingerknuckle-print(FKP),has been developed for individual verification.The proposed system carries key steps such as preprocessing,segmentation,feature extraction and classification.Initially input FKP image is fed into the preprocessing stage where colour images are converted to gray scale image for augmenting the system performance.Afterwards,segmentation process is carried out with the help of CROI(Circular Region of Interest)and Morphological operation.Then,feature extraction stage is carried out using Gabor-Derivative line approach for extracting intrinsic features.Finally,DCNN(Deep Convolutional Neural Network)is trained for the processed knuckle images to recognize imposter and genuine individuals.Extensive experiments on standard FKP database demonstrates that the proposed method attains considerable improvement compared with state-of-the-art methods.The overall accuracy attained for the proposed methodology is 95.6%which is achieved better than the existing techniques.展开更多
2N + 1-soliton solutions of Boussinesq-Burgers equation are obtained by using the Hirota bilinear derivative method and the perturbation technique.Further,we give the graphs of corresponding three-and five-soliton sol...2N + 1-soliton solutions of Boussinesq-Burgers equation are obtained by using the Hirota bilinear derivative method and the perturbation technique.Further,we give the graphs of corresponding three-and five-soliton solutions.展开更多
With the rise of the study of English learning strategies, scholars such as Wen Qiufang and Wang Lifei have found that vocabulary strategies have the highest predictive power on vocabulary level and have a significant...With the rise of the study of English learning strategies, scholars such as Wen Qiufang and Wang Lifei have found that vocabulary strategies have the highest predictive power on vocabulary level and have a significant impact on the improvement of English scores. Therefore, many educators are looking for effective ways to guide students to actively use vocabulary learning strategies. This study takes the undergraduate students of Inner Mongolia Medical University as the research object, and explores the positive effect of the derivative method of mind mapping on the use of vocabulary learning strategies from an empirical perspective.展开更多
Steady-state periodical response is investigated for an axially moving viscoelastic beam with hybrid supports via approximate analysis with numerical confirmation. It is assumed that the excitation is spatially unifor...Steady-state periodical response is investigated for an axially moving viscoelastic beam with hybrid supports via approximate analysis with numerical confirmation. It is assumed that the excitation is spatially uniform and temporally harmonic. The transverse motion of axially moving beams is governed by a nonlinear partial-differential equation and a nonlinear integro-partial-differential equation. The material time derivative is used in the viscoelastic constitutive relation. The method of multiple scales is applied to the governing equations to investigate primary resonances under general boundary conditions. It is demonstrated that the mode uninvolved in the resonance has no effect on the steady-state response. Numerical examples are presented to demonstrate the effects of the boundary constraint stiffness on the amplitude and the stability of the steady-state response. The results derived for two governing equations are qualitatively the same,but quantitatively different. The differential quadrature schemes are developed to verify those results via the method of multiple scales.展开更多
That the photosensitive action of hematoporphyrin can damage tumor cells, has attracted much attention recently. However, its mechanism of action is not very clear. Some reported that the damage is due to the producti...That the photosensitive action of hematoporphyrin can damage tumor cells, has attracted much attention recently. However, its mechanism of action is not very clear. Some reported that the damage is due to the production of singlet oxygen （1O2）, a cy-展开更多
An analysis of the delay Doppler maps(DDMs) data from the CYGNSS satellites is implemented to derive the sea surface height(SSH). An SSH estimation algorithm, the leading edge derivation(LED) method which is applied t...An analysis of the delay Doppler maps(DDMs) data from the CYGNSS satellites is implemented to derive the sea surface height(SSH). An SSH estimation algorithm, the leading edge derivation(LED) method which is applied to the delay waveforms, is applied to the DDMs, while the tropospheric delay methods, the Saastamoinen method(SM)and the numerical method(NM) are used. The results show that when the SSH from Jason-2 is referred to as the truth, if the tropospheric delay is corrected, the SSH bias can decrease. The resulted SSH bias from the Jason-2 SSH by the LED retrieval method is of order meter. The resulted SSH deviation from the truth by the NM scheme is half as small as that by the SM scheme. Since the SM scheme is not applicable to the nonhydrostatical condition, the resulted bias is larger.The work can be applied to the Beidou system in the future.展开更多
OBJECTIVE: To explore the possibility of expression of exogenous gene in transduced bone marrow derived stromal cells (BMSCs). METHODS: The marker gene, pbLacZ, was transferred into cultured BMSCs and the expression o...OBJECTIVE: To explore the possibility of expression of exogenous gene in transduced bone marrow derived stromal cells (BMSCs). METHODS: The marker gene, pbLacZ, was transferred into cultured BMSCs and the expression of transduced gene by X-gal staining was examined. Then plasmid pcDNA3-rhBMP7 was delivered to cultured BMSCs. Through immunohistochemical staining and RT-PCR assay, the expression of rhBMP7 gene was detected. RESULTS: The exogenous gene could be expressed efficiently in transduced BMSCs. CONCLUSION: The present study provided a theoretical basis to gene therapy on the problems of bone and cartilage tissue.展开更多
基金supported by the National Natural Science Foundation of China(No.52321004)the Delta Power Electronics Science and Education Development Program of Delta Group.
文摘With the rapid integration of renewable energy,wide-band oscillations caused by interactions between power electronic equipment and grids have emerged as one of the most critical stability issues.Existing methods are usually studied for local power systems with around one hundred nodes.However,for a large-scale power system with tens of thousands of nodes,the dimension of transfer function matrix or the order of characteristic equation is much higher.In this case,the existing methods such as eigenvalue analysis method and impedance-based method have difficulty in computation and are thus hard to utilize in practice.To fill this gap,this paper proposes a novel method named the smallest eigenvalues based logarithmic derivative(SELD)method.It obtains the dominant oscillation modes by the logarithmic derivative of the k-smallest eigenvalue curves of the sparse extended nodal admittance matrix(NAM).An oscillatory stability analysis tool is further developed based on this method.The effectiveness of the method and the tool is validated through a local power system as well as a large-scale power system.
基金Supported by the National Natural Science Foundation of China (12074295)。
文摘Hirota method is applied to solve the modified nonlinear Schrodinger equation/the derivative nonlinear Schrodinger equation(MNLSE/DNLSE) under nonvanishing boundary conditions(NVBC) and lead to a single and double-pole soliton solution in an explicit form. The general procedures of Hirota method are presented, as well as the limit approach of constructing a soliton-antisoliton pair of equal amplitude with a particular chirp. The evolution figures of these soliton solutions are displayed and analyzed. The influence of the perturbation term and background oscillation strength upon the DPS is also discussed.
基金This work was supported by the National Natural Science Foundation of China(10071037)
文摘In this paper, a new derivative free trust region method is developed based on the conic interpolation model for the unconstrained optimization. The conic interpolation model is built by means of the quadratic model function, the collinear scaling formula, quadratic approximation and interpolation. All the parameters in this model are determined by objective function interpolation condition. A new derivative free method is developed based upon this model and the global convergence of this new method is proved without any information on gradient.
文摘a-Oxo ketene dithioacetals 2 via 1,2-nucleophilie addition by methallyl magnesius chloride afforded corresponding alcohols (3). Treated with water or methanol and catalyzed by Lewis acid, the alcohols 3 were converted regiospecifical ly to substituted phenols 5' or related phenol methyl ethers 5 respectively. This reaction is a novel approach to the synthesis of phenols and their derivatives starting from non-aromatic precursors.
文摘The state of Tb3+ is investigated in liposome. When the concentration of PC is below CMC (critical micell concentration), most of Tb3+ is associated with PC, the binding constant is about 3.35×103 L/mol. When the concentration of PC is beyond CMC, most of Tb3+ is dimerized, the dimerization constant is about 3.92×104L/mol. In PC?CH?H2O system, the binding constant of Tb3+?CH complex 2.93×104L/mol is obtained.
基金Project supported by the National Natural Science Foundation of China (No.10774196)the Science Foundation Project of CQ CSTC (No.2006BB4156)Chongqing University Postgraduates'Science and Innovation Fund (No.2007A1A0030240).
文摘Applying the parametric derivation method, Peierls energy and Peierls stress are calculated with a non-sinusoidal force law in the lattice theory, while the results obtained by the power-series expansion according to sinusoidal law can be deduced as a limiting case of non- sinusoidal law. The simplified expressions of Peierls energy and Peierls stress are obtained for the limit of wide and narrow. Peierls energy and Peierls stress decrease monotonically with the factor of modification of force law. Present results can be used expediently for prediction of the correct order of magnitude of Peierls stress for materials.
基金financially supported by Postdoctoral Science Foundation of China (No. 2014M550222)Shanghai Postdoctoral Sustentation Fund (No. 14R21410500)+2 种基金the support from School of Pharmacy, Fudan University & the Open Project Program of Key Lab of Smart Drug Delivery (Fudan University), Ministry of Education (No. SDD2014-2)State Key Laboratory of Molecular Engineering of Polymers (Fudan University, No. K2015-15)the Fundamental Research Funds for the Central Universities (Nos. 22A201514055 and WY1213013 ECUST)
文摘This research was aim to develop novel cyclodextrin/chitosan （CD/CS） nanocarriers for insoluble drug delivery through the mild ionic gelation method previously developed by our lab. A series of different β- cyclodextrin （β-CD） derivatives were incorporated into CS nanoparticles including hydroxypropyl-β- cyclodextrin （HP-β-CD）, sulphobutylether-β-cyclodextrin （SB-β-CD）, and 2,6-di-O-methy-βcyclodex- trin （DM-β-CD）. Various process parameters for nanoparticle preparation and their effects on physicochemical properties of CD/CS nanoparticles were investigated, such as the type of CD derivatives, CD and CS concentrations, the mass ratio of CS to TPP （CS/TRP）, and pH values. In the optimal condition, CDICS nanoparticles were obtained in the size range of 215-276 nm and with the zeta potential from 30.22 mV to 35.79 mY. Moreover, the stability study showed that the incorporation of CD rendered the CD/CS nanocarriers more stable than CS nanoparticles in PBS buffer at pH 6.8. For their easy preparation and adjustable parameters in nanoparticle formation as well as the diversified hydrophobic core of CD derivatives, the novel CD/CS nanoparticles developed herein might represent an interesting and versatile drug delivery platform for a variety of poorly water-soluble drugs with different physicochemical properties.
基金Project supported by the National Natural Science Foundation of China(Grant No.11302157)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2015JM1028)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.JB160706)Chinese–Serbian Science and Technology Cooperation for the Years 2015-2016(Grant No.3-19)
文摘The stochastic bifurcation of a generalized Duffing–van der Pol system with fractional derivative under color noise excitation is studied. Firstly, fractional derivative in a form of generalized integral with time-delay is approximated by a set of periodic functions. Based on this work, the stochastic averaging method is applied to obtain the FPK equation and the stationary probability density of the amplitude. After that, the critical parameter conditions of stochastic P-bifurcation are obtained based on the singularity theory. Different types of stationary probability densities of the amplitude are also obtained. The study finds that the change of noise intensity, fractional order, and correlation time will lead to the stochastic bifurcation.
文摘Regarding the rapid compensation of the influence of the Earth＇ s disturbing gravity field upon trajectory calculation,the key point lies in how to derive the analytical solutions to the partial derivatives of the state of burnout point with respect to the launch data.In view of this,this paper mainly expounds on two issues：one is based on the approximate analytical solution to the motion equation for the vacuum flight section of a long-range rocket,deriving the analytical solutions to the partial derivatives of the state of burnout point with respect to the changing rate of the finalstage pitch program;the other is based on the initial positioning and orientation error propagation mechanism,proposing the analytical calculation formula for the partial derivatives of the state of burnout point with respect to the launch azimuth.The calculation results of correction data are simulated and verified under different circumstances.The simulation results are as follows：（1） the accuracy of approximation between the analytical solutions and the results attained via the difference method is higher than 90%,and the ratio of calculation time between them is lower than 0.2%,thus demonstrating the accuracy of calculation of data corrections and advantages in calculation speed;（2） after the analytical solutions are compensated,the longitudinal landing deviation of the rocket is less than 20 m and the lateral landing deviation of the rocket is less than 10 m,demonstrating that the corrected data can meet the requirements for the hit accuracy of a long-range rocket.
基金supported by the National Natural Science Foundation of China(Grants 11472161,11102102,and 91130017)the Independent Innovation Foundation of Shandong University(Grant 2013ZRYQ002)the Natural Science Foundation of Shandong Province(Grant ZR2014AQ015)
文摘In this paper,we propose a numerical method to estimate the unknown order of a Riemann-Liouville fractional derivative for a fractional Stokes＇ first problem for a heated generalized second grade fluid.The implicit numerical method is employed to solve the direct problem.For the inverse problem,we first obtain the fractional sensitivity equation by means of the digamma function,and then we propose an efficient numerical method,that is,the Levenberg-Marquardt algorithm based on a fractional derivative,to estimate the unknown order of a Riemann-Liouville fractional derivative.In order to demonstrate the effectiveness of the proposed numerical method,two cases in which the measurement values contain random measurement error or not are considered.The computational results demonstrate that the proposed numerical method could efficiently obtain the optimal estimation of the unknown order of a RiemannLiouville fractional derivative for a fractional Stokes＇ first problem for a heated generalized second grade fluid.
基金Project supported by the Key Program of the National Natural Science Foundation of China （Grant No. 51134018）.
文摘The variational iteration method is successfully extended to the case of solving fractional differential equations, and the Lagrange multiplier of the method is identified in a more accurate way. Some diffusion models with fractional derivatives are investigated analytically, and the results show the efficiency of the new Lagrange multiplier for fractional differential equations of arbitrary order.
文摘The treatment of advective fluxes in high-order finite volume models is well established, but this is not the case for diffusive fluxes, due to the conflict between the discontinuous representation of the solution and the continuous structure of analytic solutions. In this paper, a derivative reconstruction approach is proposed in the context of spectral volume methods, for the approximation of diffusive fluxes, aiming at the reconciliation of this conflict. Two different reconstructions are used for advective and diffusive fluxes： the advective reconstruction makes use of the information contained in a spectral cell, and allows the formation of discontinuities at the spectral cells boundaries; the diffusive reconstruction makes use of the information contained in contiguous spectral cells, imposing the continuity of the reconstruction at the spectral cells boundaries. The method is demonstrated by a number of numerical experiments, including the solution of shallow-water equations, complemented with the advective-diffusive transport equation of a conservative substance, showing the promising abilities of the numerical scheme proposed.
文摘We introduce conformable fractional Nikiforov–Uvarov(NU) method by means of conformable fractional derivative which is the most natural definition in non-integer calculus. Since, NU method gives exact eigenstate solutions of Schr¨odinger equation(SE) for certain potentials in quantum mechanics, this method is carried into the domain of fractional calculus to obtain the solutions of fractional SE. In order to demonstrate the applicability of the conformable fractional NU method, we solve fractional SE for harmonic oscillator potential, Woods–Saxon potential, and Hulthen potential.
文摘One of the evolving hand biometric features considered so far is finger knuckle printing,because of its ability towards unique identification of individuals.Despite many attempts have been made in this area of research,the accuracy of the recognition model remains a major issue.To overcome this problem,a novel biometric-based method,named fingerknuckle-print(FKP),has been developed for individual verification.The proposed system carries key steps such as preprocessing,segmentation,feature extraction and classification.Initially input FKP image is fed into the preprocessing stage where colour images are converted to gray scale image for augmenting the system performance.Afterwards,segmentation process is carried out with the help of CROI(Circular Region of Interest)and Morphological operation.Then,feature extraction stage is carried out using Gabor-Derivative line approach for extracting intrinsic features.Finally,DCNN(Deep Convolutional Neural Network)is trained for the processed knuckle images to recognize imposter and genuine individuals.Extensive experiments on standard FKP database demonstrates that the proposed method attains considerable improvement compared with state-of-the-art methods.The overall accuracy attained for the proposed methodology is 95.6%which is achieved better than the existing techniques.
基金The NSF(11271008)of Chinathe First-class Discipline of University in Shanghai and the Shanghai Univ.Leading Academic Discipline Project(A.13-0101-12-004)
文摘2N + 1-soliton solutions of Boussinesq-Burgers equation are obtained by using the Hirota bilinear derivative method and the perturbation technique.Further,we give the graphs of corresponding three-and five-soliton solutions.
文摘With the rise of the study of English learning strategies, scholars such as Wen Qiufang and Wang Lifei have found that vocabulary strategies have the highest predictive power on vocabulary level and have a significant impact on the improvement of English scores. Therefore, many educators are looking for effective ways to guide students to actively use vocabulary learning strategies. This study takes the undergraduate students of Inner Mongolia Medical University as the research object, and explores the positive effect of the derivative method of mind mapping on the use of vocabulary learning strategies from an empirical perspective.
基金supported by the National Natural Science Foundation of China (10902064 and 10932006)China National Funds for Distinguished Young Scientists (10725209)+2 种基金the Program of Shanghai Subject Chief Scientist (09XD1401700)Shanghai Leading Talent Program,Shanghai Leading Academic Discipline Project (S30106)the program for Cheung Kong Scholars Programme and Innovative Research Team in University (IRT0844)
文摘Steady-state periodical response is investigated for an axially moving viscoelastic beam with hybrid supports via approximate analysis with numerical confirmation. It is assumed that the excitation is spatially uniform and temporally harmonic. The transverse motion of axially moving beams is governed by a nonlinear partial-differential equation and a nonlinear integro-partial-differential equation. The material time derivative is used in the viscoelastic constitutive relation. The method of multiple scales is applied to the governing equations to investigate primary resonances under general boundary conditions. It is demonstrated that the mode uninvolved in the resonance has no effect on the steady-state response. Numerical examples are presented to demonstrate the effects of the boundary constraint stiffness on the amplitude and the stability of the steady-state response. The results derived for two governing equations are qualitatively the same,but quantitatively different. The differential quadrature schemes are developed to verify those results via the method of multiple scales.
文摘That the photosensitive action of hematoporphyrin can damage tumor cells, has attracted much attention recently. However, its mechanism of action is not very clear. Some reported that the damage is due to the production of singlet oxygen （1O2）, a cy-
基金National Natural Science Foundation of China(41875060, U1606405)。
文摘An analysis of the delay Doppler maps(DDMs) data from the CYGNSS satellites is implemented to derive the sea surface height(SSH). An SSH estimation algorithm, the leading edge derivation(LED) method which is applied to the delay waveforms, is applied to the DDMs, while the tropospheric delay methods, the Saastamoinen method(SM)and the numerical method(NM) are used. The results show that when the SSH from Jason-2 is referred to as the truth, if the tropospheric delay is corrected, the SSH bias can decrease. The resulted SSH bias from the Jason-2 SSH by the LED retrieval method is of order meter. The resulted SSH deviation from the truth by the NM scheme is half as small as that by the SM scheme. Since the SM scheme is not applicable to the nonhydrostatical condition, the resulted bias is larger.The work can be applied to the Beidou system in the future.
文摘OBJECTIVE: To explore the possibility of expression of exogenous gene in transduced bone marrow derived stromal cells (BMSCs). METHODS: The marker gene, pbLacZ, was transferred into cultured BMSCs and the expression of transduced gene by X-gal staining was examined. Then plasmid pcDNA3-rhBMP7 was delivered to cultured BMSCs. Through immunohistochemical staining and RT-PCR assay, the expression of rhBMP7 gene was detected. RESULTS: The exogenous gene could be expressed efficiently in transduced BMSCs. CONCLUSION: The present study provided a theoretical basis to gene therapy on the problems of bone and cartilage tissue.
