The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet (DSPM) motor. Compared with common three-phase bridge inverters, the proposed inve...The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet (DSPM) motor. Compared with common three-phase bridge inverters, the proposed inverter works under more complicated conditions with different principles for special winding back EMFs, position signals of hall sensors, and the given mode of switches. The ideal steady driving principles of the inverter for the motor are given. The working state with asymmetric winding back EMFs, inaccurate position signals of hall sensors, and the changing input voltage is analyzed. Finally, experimental results vertify that the given anal ysis is correct.展开更多
Surface charge characteristics of a membrane can be determined by the streaming potential. In order to obtain more accurate streaming potential value during the measurement, four measurement operation modes were inves...Surface charge characteristics of a membrane can be determined by the streaming potential. In order to obtain more accurate streaming potential value during the measurement, four measurement operation modes were investigated in this study, and among the four modes, the steady mode with pressure stepped downward was considered the best one. Experimental results showed that the effects of compaction on the streaming potential measurement for a microfiltration membrane was more obvious than that for a ultrafiltration membrane. Both feed pH and presoaking could affect the measurement of streaming potential.展开更多
The effects of the cell parameter and chemical composition on the surface charge properties of five kinds of different colour montmorillonites were studied. The results indicate that the surface isoelectric point(IEP...The effects of the cell parameter and chemical composition on the surface charge properties of five kinds of different colour montmorillonites were studied. The results indicate that the surface isoelectric point(IEP) of the montmorillonite shows positive correlation with the mass fractions of Fe203 and K20, but it has little relation to the mass fractions of other chemical compositions. At around pH=6.8, the surface zeta potential of the montmorillonite shows the negative relationship with the mass fractions of Fe203 and MgO, but it does not linearly correlate to the mass fractions of other chemical compositions. Cell parameter(bo) of the montmorillonite expresses negative linear relationship with mass fractions of K2O and Na2O, so does cosinβ with mass fractions of SlOE and Fe2O3. And there is no specific relationship between bo and IEP of different montmorillonites, but there is positive correlation between cosinβ and IEP of different montmorillonite samples.展开更多
OBJECTIVE To investigate the potential malignant characteristics and pathogenesis of endometriosis as well as the role of human growth hormone and epidermal growth factor receptor in the pathogenesis of malignant tran...OBJECTIVE To investigate the potential malignant characteristics and pathogenesis of endometriosis as well as the role of human growth hormone and epidermal growth factor receptor in the pathogenesis of malignant transformation of endometriosis. METHODS The immunohistochemical S-P method was used to examine the expression of human growth hormone and epidermal growth factor receptor in the eutopic and ectopic endometrium of 84 cases of endometriosis. RESULTS The percentage of positive cases of human growth hormone in eutopic and ectopic endometrium was 90.77% (59/65) and 85.71% (72/ 84) respectively. The percentage of positive cases of epidermal growth factor receptor in eutopic and ectopic endometrium was 81.54% (53/65) and 89.29% (75/84) respectively. The positive rate of epidermal growth factor receptor in ectopic endometrium was higher than that in the eutopic endometrium but without a statistically significant difference (P〉 0.05). CONCLUSION Endometriosis is caused by multiple factors, which possesses some biologic features of neoplastic tissue such as invasion and metastasis. Both human growth hormone and epidermal growth factor receptor are highly expressed in eutopic and ectopic endometrium, which lead directly or indirectly to the pathogenesis of endometriosis and promote the initiation and malignant transformation of endometriosis.展开更多
The method in which a source is set on the surface and electric potential is received in the borehole is called surface-borehole electric potential technique. Technique of surface-borehole electric potential was emplo...The method in which a source is set on the surface and electric potential is received in the borehole is called surface-borehole electric potential technique. Technique of surface-borehole electric potential was employed to study electric response of layered formation. The electric potential was obtained by solving Poisson equation with finite difference method. In the course of calculation, forward modeling wilth finite difference method was realized by adopting bandwidth non-zero storage technique and the incomplete Cholesky conjugate gradient method. The results show that method of surface-borehole can acquire anomalous electric potential corresponding tc geo-electric layers. In addition, application of appropriate mathematical operator can improve the resolution. Moreover, overburden low resistivity layers have severe influence on measuring results of surface-borehole electric potential. However, bottom low resistivity layers play a positive role in the measurement.展开更多
Approximate bound state solutions of spinless particles with a special case of equal scalar and vector modified generalized Hulthen potential has been obtained under the massive Klein-Gordon equation. The energy eigen...Approximate bound state solutions of spinless particles with a special case of equal scalar and vector modified generalized Hulthen potential has been obtained under the massive Klein-Gordon equation. The energy eigenvalues and the corresponding wave functions expressed in terms of a Jacobi polynomial are also obtained using the parametric generalization of the Nikiforov-Uvarov (NU) method. Under limiting cases our result are in agreement with the existing literature. Our results could be used to study the interactions and binding energies of the central potential for diatomic molecules in the relativistic framework which have many applications in physics and some others related disciplines.展开更多
The analytic solution of the radial Schrodinger equation is studied by using the tight coupling condition of several positive-power and inverse-power potential functions in this article. Furthermore, the precisely ana...The analytic solution of the radial Schrodinger equation is studied by using the tight coupling condition of several positive-power and inverse-power potential functions in this article. Furthermore, the precisely analytic solutions and the conditions that decide the existence of analytic solution have been searched when the potential of the radial Schrodinger equation is V(r) =α1r^8 +α2r^3 + α3r^2 +β3r^-1 +β2r^-3 +β1r6-4. Generally speaking, there is only an approximate solution, but not analytic solution for SchrSdinger equation with several potentials' superposition. However, the conditions that decide the existence of analytic solution have been found and the analytic solution and its energy level structure are obtained for the Schrodinger equation with the potential which is motioned above in this paper. According to the single-value, finite and continuous standard of wave function in a quantum system, the authors firstly solve the asymptotic solution through the radial coordinate r → ∞ and r →0; secondly, they make the asymptotic solutions combining with the series solutions nearby the neighborhood of irregular singularities; and then they compare the power series coefficients, deduce a series of analytic solutions of the stationary state wave function and corresponding energy level structure by tight coupling among the coefficients of potential functions for the radial SchrSdinger equation; and lastly, they discuss the solutions and make conclusions.展开更多
The large-scale assembly and fabrication method for single-walled carbon nanotube(SWCNT) nano devices was implemented.Assembly of SWCNT field effect transistor(FET) was realized by floating potential dielectrophoresis...The large-scale assembly and fabrication method for single-walled carbon nanotube(SWCNT) nano devices was implemented.Assembly of SWCNT field effect transistor(FET) was realized by floating potential dielectrophoresis approach.The simulation of floating potential distribution of the chip was performed by comsol multiphysics coupling software.Six hundred devices were assembled on the area of less than one square centimeter.The fabricated devices were characterized by atomic force microscopy and scanning electron microscopy.The experimental results showed that large-scale assembly had been realized,and the success rate of ideal assembly for SWCNT FET had been assessed.展开更多
To improve the efficiency of nano-electronic device fabrication, a new method named floating electrical potential assembly is proposed to realize large-scale assembly of Cu/CuO nanowires, The simulation of floating el...To improve the efficiency of nano-electronic device fabrication, a new method named floating electrical potential assembly is proposed to realize large-scale assembly of Cu/CuO nanowires, The simulation of floating electrical potential distribution on the micro-electrode chip is performed by COMSOL software, and the simulation result shows that the coupled electrical poten- tial on the floating drain electrodes is very close to the original electrical potential applied on the gate electrode, whicb means that the method can provide di-electrophoresis (DEP) force for all the electrode pairs at one time, thus realizing large-scale as- sembly at one time. With Cu/CuO nanowires well dispersed and micro-electrode chip fabrication, nanowires assembly experiments are performed and the experimental results show that Cu/CuO nanowires are assembled at hundreds of micro-electrodes pairs at one time, and the success rate of nanowires assembly also reaches 90%.展开更多
We verify the accuracy of the curvature-based potential.By means of the idealized numerical experiment,we show that the curvature-based potential is in good agreement with the numerical experiment,and the errors are w...We verify the accuracy of the curvature-based potential.By means of the idealized numerical experiment,we show that the curvature-based potential is in good agreement with the numerical experiment,and the errors are within a reasonable range.Based on the curvature-based potential,the equipotential surfaces of particles are derived,and the intrinsic relations between the equipotential surfaces and Weingarten helicoids are shown.展开更多
Nb-doped TiAl alloys exhibit excellent mechanical properties at high temperatures,and the underlying mechanism and optimal doping amount remain elusive.Molecular dynamics simulation is helpful to clarify these problem...Nb-doped TiAl alloys exhibit excellent mechanical properties at high temperatures,and the underlying mechanism and optimal doping amount remain elusive.Molecular dynamics simulation is helpful to clarify these problems,but most of the existing interatomic potentials are limited to the Ti-Al binary system and lack interatomic potentials for doped alloys.Here,an intera-tomic potential of Nb-Al-Ti ternary systems based on the modified embedded-atom method was developed.The ternary potential can accurately predict the structure and thermodynamic properties of the Nb-Al-Ti system.The potential shows that the optimal Nb content for high-temperature strength-ductility synergy of TiAl single crystals is 8%,consistent with the amount of miracle synthesis of TiAl single crystals.Tensile simulations further show that the developed potential can make an effective prediction at high temperatures,indicating the potential for the development and applications of high-temperature Nb-Al-Ti ternary systems.展开更多
The retainability of canonical distributions for a Brownian particle controlled by a time-dependent harmonic potential is investigated in the overdamped and underdamped situations, respectively. Because of different t...The retainability of canonical distributions for a Brownian particle controlled by a time-dependent harmonic potential is investigated in the overdamped and underdamped situations, respectively. Because of different time scales, the overdamped and underdamped Langevin equations(as well as the corresponding Fokker-Planck equations) lead to distinctive restrictions on protocols maintaining canonical distributions. Two special cases are analyzed in details: First, a Brownian particle is controlled by a time-dependent harmonic potential and embedded in medium with constant temperature; Second, a Brownian particle is controlled by a timedependent harmonic potential and embedded in a medium whose temperature is tuned together with the potential stiffness to keep a constant effective temperature of the Brownian particle. We find that the canonical distributions are usually retainable for both the overdamped and underdamped situations in the former case. However, the canonical distributions are retainable merely for the overdamped situation in the latter case. We also investigate general time-dependent potentials beyond the harmonic form and find that the retainability of canonical distributions depends sensitively on the specific form of potentials.展开更多
文摘The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet (DSPM) motor. Compared with common three-phase bridge inverters, the proposed inverter works under more complicated conditions with different principles for special winding back EMFs, position signals of hall sensors, and the given mode of switches. The ideal steady driving principles of the inverter for the motor are given. The working state with asymmetric winding back EMFs, inaccurate position signals of hall sensors, and the changing input voltage is analyzed. Finally, experimental results vertify that the given anal ysis is correct.
基金the National Natural Science Foundation of China (No.29976031), the Collaboration Project Foundation of Tianjin University and Nankal University, and the Key Project Foundation of Tianjin (No.0331810112).
文摘Surface charge characteristics of a membrane can be determined by the streaming potential. In order to obtain more accurate streaming potential value during the measurement, four measurement operation modes were investigated in this study, and among the four modes, the steady mode with pressure stepped downward was considered the best one. Experimental results showed that the effects of compaction on the streaming potential measurement for a microfiltration membrane was more obvious than that for a ultrafiltration membrane. Both feed pH and presoaking could affect the measurement of streaming potential.
基金Project(2005CB623701) supported by the Major State Basic Research Development Program of China
文摘The effects of the cell parameter and chemical composition on the surface charge properties of five kinds of different colour montmorillonites were studied. The results indicate that the surface isoelectric point(IEP) of the montmorillonite shows positive correlation with the mass fractions of Fe203 and K20, but it has little relation to the mass fractions of other chemical compositions. At around pH=6.8, the surface zeta potential of the montmorillonite shows the negative relationship with the mass fractions of Fe203 and MgO, but it does not linearly correlate to the mass fractions of other chemical compositions. Cell parameter(bo) of the montmorillonite expresses negative linear relationship with mass fractions of K2O and Na2O, so does cosinβ with mass fractions of SlOE and Fe2O3. And there is no specific relationship between bo and IEP of different montmorillonites, but there is positive correlation between cosinβ and IEP of different montmorillonite samples.
文摘OBJECTIVE To investigate the potential malignant characteristics and pathogenesis of endometriosis as well as the role of human growth hormone and epidermal growth factor receptor in the pathogenesis of malignant transformation of endometriosis. METHODS The immunohistochemical S-P method was used to examine the expression of human growth hormone and epidermal growth factor receptor in the eutopic and ectopic endometrium of 84 cases of endometriosis. RESULTS The percentage of positive cases of human growth hormone in eutopic and ectopic endometrium was 90.77% (59/65) and 85.71% (72/ 84) respectively. The percentage of positive cases of epidermal growth factor receptor in eutopic and ectopic endometrium was 81.54% (53/65) and 89.29% (75/84) respectively. The positive rate of epidermal growth factor receptor in ectopic endometrium was higher than that in the eutopic endometrium but without a statistically significant difference (P〉 0.05). CONCLUSION Endometriosis is caused by multiple factors, which possesses some biologic features of neoplastic tissue such as invasion and metastasis. Both human growth hormone and epidermal growth factor receptor are highly expressed in eutopic and ectopic endometrium, which lead directly or indirectly to the pathogenesis of endometriosis and promote the initiation and malignant transformation of endometriosis.
基金Project supported by Global Center of Excellence in Novel Carbon Resource Sciences,Kyushu University,Japan
文摘The method in which a source is set on the surface and electric potential is received in the borehole is called surface-borehole electric potential technique. Technique of surface-borehole electric potential was employed to study electric response of layered formation. The electric potential was obtained by solving Poisson equation with finite difference method. In the course of calculation, forward modeling wilth finite difference method was realized by adopting bandwidth non-zero storage technique and the incomplete Cholesky conjugate gradient method. The results show that method of surface-borehole can acquire anomalous electric potential corresponding tc geo-electric layers. In addition, application of appropriate mathematical operator can improve the resolution. Moreover, overburden low resistivity layers have severe influence on measuring results of surface-borehole electric potential. However, bottom low resistivity layers play a positive role in the measurement.
文摘Approximate bound state solutions of spinless particles with a special case of equal scalar and vector modified generalized Hulthen potential has been obtained under the massive Klein-Gordon equation. The energy eigenvalues and the corresponding wave functions expressed in terms of a Jacobi polynomial are also obtained using the parametric generalization of the Nikiforov-Uvarov (NU) method. Under limiting cases our result are in agreement with the existing literature. Our results could be used to study the interactions and binding energies of the central potential for diatomic molecules in the relativistic framework which have many applications in physics and some others related disciplines.
基金supported by the National Natural Science Foundation of China under Grant No.10575140the Basic Research of Chongqing Education Committee under Grant No.KJ060813
文摘The analytic solution of the radial Schrodinger equation is studied by using the tight coupling condition of several positive-power and inverse-power potential functions in this article. Furthermore, the precisely analytic solutions and the conditions that decide the existence of analytic solution have been searched when the potential of the radial Schrodinger equation is V(r) =α1r^8 +α2r^3 + α3r^2 +β3r^-1 +β2r^-3 +β1r6-4. Generally speaking, there is only an approximate solution, but not analytic solution for SchrSdinger equation with several potentials' superposition. However, the conditions that decide the existence of analytic solution have been found and the analytic solution and its energy level structure are obtained for the Schrodinger equation with the potential which is motioned above in this paper. According to the single-value, finite and continuous standard of wave function in a quantum system, the authors firstly solve the asymptotic solution through the radial coordinate r → ∞ and r →0; secondly, they make the asymptotic solutions combining with the series solutions nearby the neighborhood of irregular singularities; and then they compare the power series coefficients, deduce a series of analytic solutions of the stationary state wave function and corresponding energy level structure by tight coupling among the coefficients of potential functions for the radial SchrSdinger equation; and lastly, they discuss the solutions and make conclusions.
基金supported by the National Natural Science Foundation of China (Grant No. 51005230)China Postdoctoral Science Foundation(Grant No. 2012M520654)the Education Department of Liaoning Province Science and Technology Research Projects (Grant No. L2012213)
文摘The large-scale assembly and fabrication method for single-walled carbon nanotube(SWCNT) nano devices was implemented.Assembly of SWCNT field effect transistor(FET) was realized by floating potential dielectrophoresis approach.The simulation of floating potential distribution of the chip was performed by comsol multiphysics coupling software.Six hundred devices were assembled on the area of less than one square centimeter.The fabricated devices were characterized by atomic force microscopy and scanning electron microscopy.The experimental results showed that large-scale assembly had been realized,and the success rate of ideal assembly for SWCNT FET had been assessed.
基金supported by the National Natural Science Foundation of China(Grant No.51005230)China Postdoctoral Science Foundation(Grant No.2012M520654)the Education Department of Liaoning Province Science and Ttechnology Research Projects(Grant No.L2012213)
文摘To improve the efficiency of nano-electronic device fabrication, a new method named floating electrical potential assembly is proposed to realize large-scale assembly of Cu/CuO nanowires, The simulation of floating electrical potential distribution on the micro-electrode chip is performed by COMSOL software, and the simulation result shows that the coupled electrical poten- tial on the floating drain electrodes is very close to the original electrical potential applied on the gate electrode, whicb means that the method can provide di-electrophoresis (DEP) force for all the electrode pairs at one time, thus realizing large-scale as- sembly at one time. With Cu/CuO nanowires well dispersed and micro-electrode chip fabrication, nanowires assembly experiments are performed and the experimental results show that Cu/CuO nanowires are assembled at hundreds of micro-electrodes pairs at one time, and the success rate of nanowires assembly also reaches 90%.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11072125 and 10872114)the Natural Science Foundation of Jiangsu Province (Grant No. SBK201140044)
文摘We verify the accuracy of the curvature-based potential.By means of the idealized numerical experiment,we show that the curvature-based potential is in good agreement with the numerical experiment,and the errors are within a reasonable range.Based on the curvature-based potential,the equipotential surfaces of particles are derived,and the intrinsic relations between the equipotential surfaces and Weingarten helicoids are shown.
基金the National Key Research and Development Program of China(Grant No.2019YF40705400)National Natural Science Foundation of China(Grant Nos.51535005,51731006,and 51771093)+2 种基金the Research Fund of State Key Laboratory of Mechanics and Control of Me-chanical Structures(Grant Nos.MCMS-I-0418K01,MCMS-I-0419K01)the Fundamental Research Funds for the Central Universities(Grant Nos.NZ2020001,NC2018001,NP2019301,NJ20I 9002,and 30919011295)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Nb-doped TiAl alloys exhibit excellent mechanical properties at high temperatures,and the underlying mechanism and optimal doping amount remain elusive.Molecular dynamics simulation is helpful to clarify these problems,but most of the existing interatomic potentials are limited to the Ti-Al binary system and lack interatomic potentials for doped alloys.Here,an intera-tomic potential of Nb-Al-Ti ternary systems based on the modified embedded-atom method was developed.The ternary potential can accurately predict the structure and thermodynamic properties of the Nb-Al-Ti system.The potential shows that the optimal Nb content for high-temperature strength-ductility synergy of TiAl single crystals is 8%,consistent with the amount of miracle synthesis of TiAl single crystals.Tensile simulations further show that the developed potential can make an effective prediction at high temperatures,indicating the potential for the development and applications of high-temperature Nb-Al-Ti ternary systems.
基金supported by the National Natural Science Foundation of China(Grant No.11322543)the Fundamental Research Funds for the Central Universities(Grant No.2015KJJCB01)
文摘The retainability of canonical distributions for a Brownian particle controlled by a time-dependent harmonic potential is investigated in the overdamped and underdamped situations, respectively. Because of different time scales, the overdamped and underdamped Langevin equations(as well as the corresponding Fokker-Planck equations) lead to distinctive restrictions on protocols maintaining canonical distributions. Two special cases are analyzed in details: First, a Brownian particle is controlled by a time-dependent harmonic potential and embedded in medium with constant temperature; Second, a Brownian particle is controlled by a timedependent harmonic potential and embedded in a medium whose temperature is tuned together with the potential stiffness to keep a constant effective temperature of the Brownian particle. We find that the canonical distributions are usually retainable for both the overdamped and underdamped situations in the former case. However, the canonical distributions are retainable merely for the overdamped situation in the latter case. We also investigate general time-dependent potentials beyond the harmonic form and find that the retainability of canonical distributions depends sensitively on the specific form of potentials.