A new two-dimensional （2D） analytical model for the threshold-voltage of fully depleted SOI MOSFETs is derived. The 2D potential distribution functions in the active layer of the devices are obtained through solving...A new two-dimensional （2D） analytical model for the threshold-voltage of fully depleted SOI MOSFETs is derived. The 2D potential distribution functions in the active layer of the devices are obtained through solving the 2D Poisson＇s equation. The minimum of the potential at the oxide-Si layer interface is used to monitor the threshold voltage of the SOI MOSFETs. This model is verified by its excellent agreement with MEDICI simulation using SOI MOSFETs with different gate lengths,gate oxide thicknesses,silicon film thicknesses,and channel doping concentrations.展开更多
A novel approximation of the two-dimensional （2D） potential function perpendicular to the channel is proposed,and then an analytical threshold voltage model for a fully depleted SOI-MOSFET with a non-uniform Gaussia...A novel approximation of the two-dimensional （2D） potential function perpendicular to the channel is proposed,and then an analytical threshold voltage model for a fully depleted SOI-MOSFET with a non-uniform Gaussian distribution doping profile is given based on this approximation. The model agrees well with numerical simulation by MEDICI. The result represents a new way and some reference points in analyzing and controlling the threshold voltage of non-uniform fully depleted （FD） SOI devices in practice.展开更多
Rapid technological development and population growth are responsible for a series of imminent environmental problems and an ineluctable energy crisis.The application of semiconductor nanomaterials in photocatalysis o...Rapid technological development and population growth are responsible for a series of imminent environmental problems and an ineluctable energy crisis.The application of semiconductor nanomaterials in photocatalysis or photoelectrocatalysis(PEC)for either the degradation of contaminants in the environment or the generation of hydrogen as clean fuel is an effective approach to alleviate these problems.However,the efficiency of such processes remains suboptimal for real applications.Reasonable construction of a built-in electric field is considered to efficiently enhance carrier separation and reduce carrier recombination to improve catalytic performance.In the past decade,as a new method to enhance the built-in electric field,the piezoelectric effect from piezoelectric materials has been extensively studied.In this review,we provide an overview of the properties of piezoelectric materials and the mechanisms of piezoelectricity and ferroelectricity for a built-in electric field.Then,piezoelectric and ferroelectric polarization regulated built-in electric fields that mediate catalysis are discussed.Furthermore,the applications of piezoelectric semiconductor materials are also highlighted,including degradation of pollutants,bacteria disinfection,water splitting for H2 generation,and organic synthesis.We conclude by discussing the challenges in the field and the exciting opportunities to further improve piezo-catalytic efficiency.展开更多
A simple barotropic potential vorticity equation with the influence of dissipation is applied to investigate the nonlinear Rossby wave in a shear flow in the tropical atmophere. By the reduetive perturbation method, w...A simple barotropic potential vorticity equation with the influence of dissipation is applied to investigate the nonlinear Rossby wave in a shear flow in the tropical atmophere. By the reduetive perturbation method, we derive the rotational KdV （rKdV for short） equation. And then, with the help of Jaeobi elliptie functions, we obtain various periodic structures for these Rossby waves. It is shown that dissipation is very important for these periodic structures of rational form.展开更多
A temperature-dependent model for threshold voltage and potential distribution of fully depleted silicon-on- insulator metal-oxide-semiconductor field-effect transistors is developed. The two-dimensional potential dis...A temperature-dependent model for threshold voltage and potential distribution of fully depleted silicon-on- insulator metal-oxide-semiconductor field-effect transistors is developed. The two-dimensional potential distribution function in the silicon thin film based on an approximate parabolic function has been applied to solve the two-dimensional Poisson＇s equation with suitable boundary conditions. The minimum of the surface potential is used to deduce the threshold voltage model. The model reveals the variations of potential distribution and threshold voltage with temperature, taking into account short-channel effects. Furthermore, the model is verified by the SILVACO ATLAS simulation. The calculations and the simulation agree well.展开更多
A quasi two-dimensional （2D） analytical model of a double-gate （DG） MOSFET with Schottky source/drain is developed based on the Poisson equation.The 2D potential distribution in the channel is calculated.An expres...A quasi two-dimensional （2D） analytical model of a double-gate （DG） MOSFET with Schottky source/drain is developed based on the Poisson equation.The 2D potential distribution in the channel is calculated.An expression for threshold voltage for a short-channel DG MOSFET with Schottky S/D is also presented by defining the turn-on condition.The results of the model are verified by the numerical simulator DESSIS-ISE.展开更多
Unidirectional transport of a particle in a spatially periodic and symmetric potential under a periodic force with broken temporal symmetry is studied. With a collaboration of the potential field and the asymmetric ac...Unidirectional transport of a particle in a spatially periodic and symmetric potential under a periodic force with broken temporal symmetry is studied. With a collaboration of the potential field and the asymmetric ac force, a dc current can be observed. Resonant current steps are found for a finite period of the ac force. A phase diagram of these resonant steps is given. Stochastic-resonance-like directional transport induced by thermal noises is revealed.展开更多
In this paper, we conduct research on the development trend of urbanization of the rural migrant workers from the perspectives of health and life stress. According to the theory of modern sociological about community,...In this paper, we conduct research on the development trend of urbanization of the rural migrant workers from the perspectives of health and life stress. According to the theory of modern sociological about community, the migrant worker and city people’s relations belongs to typical in community’s relations with the outside community, among them not only isolates and repels psychologically mutually, but also has the direct conflicts of interest. This not only causes the migrant worker to suffer the prejudice and discrimination of city people, is hard to be a part of the city life, but also causes repellency urban institutional arrangements to disintegrate to a certain extent difficultly while the migrant worker is hard to enter in the urban system. Under this basis, this paper proposes the health and life stress assisted development trend of urbanization of the rural migrant workers basic research, the idea is new and innovative, in the later time we will apply it more.展开更多
The analytical solutions to 1D Schrdinger equation (in depth direction) in double gate (DG) MOSFETs are derived to calculate electron density and threshold voltage.The non uniform potential in the channel is concern...The analytical solutions to 1D Schrdinger equation (in depth direction) in double gate (DG) MOSFETs are derived to calculate electron density and threshold voltage.The non uniform potential in the channel is concerned with an arbitrary depth so that the analytical solutions agree well with numerical ones.Then,an implicit expression for electron density and a closed form of threshold voltage are presented fully comprising quantum mechanical (QM) effects.This model predicts an increased electron density with an increasing channel depth in subthreshold region or mild inversion region.However,it becomes independent on channel depth in strong inversion region,which is in accordance with numerical analysis.It is also concluded that the QM model,which barely considers a box like potential in the channel,slightly over predicts threshold voltage and underestimates electron density,and the error increases with an increasing channel depth or a decreasing gate oxide thickness.展开更多
Variance analysis, correlation analysis and regression analysis methods are applied to analyze the variation of circulation at 500 hPa. In winter, there are three regions (180°E – 150°W, 45°N – 60...Variance analysis, correlation analysis and regression analysis methods are applied to analyze the variation of circulation at 500 hPa. In winter, there are three regions (180°E – 150°W, 45°N – 60°N, 70°W – 100 °W,45°N – 75°N, 60°E – 100°E, 65°N – 80°N) whose variations are strong. Those regions are the key regions in which atmospheric circulation can change. Those regions are correlated to some teleconnections and can present a part of variations of 500 hPa to some degree. The linear contemporary correlation between those regions and the height at 500 hPa is significant. Those regions can account for 88 % of variations of concurrent height at 500 hPa. Those regions can present and forecast some variations to some degree in March and April. The longer the time interval, the worse the forecast effect will be. The interannual variations of Q1, Q2 and the SST are weak in the western Pacific.展开更多
Trends in modern industry show a tendency towards demassovization of production as a response to the customers＇ specific needs for unique and personalized products. This provokes significant changes in the processes ...Trends in modern industry show a tendency towards demassovization of production as a response to the customers＇ specific needs for unique and personalized products. This provokes significant changes in the processes of manufacturing, assembly, and testing The cost of such a type of production can be reduced by employing highly productive reconfigurable equipment with proper software to enable optimization. This paper presents a decision support extension for directing of hydraulic cylinders to assembly-testing lines using fuzzy logic in the Enterprise Resource Planning system of a small size production in a factory in Bulgaria. Different assembly-testing lines are flexibly assigned to the specific cylinder＇s parameters by the developed fuzzy system on the basis of the overlapping of parameters in the hydraulic cylinders classification. The final decision on the line assigned in case of alternatives is made through accounting for the minimal cylinder delay time. The effectiveness of the approach is assessed by simulation. It leads to an increase of the efficiency of the assembly-testing flow lines, a reduction of the time needed for hydraulic cylinders assembling and testing and balanced loading of the modules.展开更多
In order to assess the influences of curved hole passage on cooling effectiveness and flow structure of turbine blade leading edge,the detached eddy simulation is applied to numerically investigate the AGTB turbine ca...In order to assess the influences of curved hole passage on cooling effectiveness and flow structure of turbine blade leading edge,the detached eddy simulation is applied to numerically investigate the AGTB turbine cascade under the condition of global blowing ratio M=0.7.The straight or curved cooling holes are located at either the pressure or suction side near the leading edge.The analysis and discussion focus on the local turbulence structure;influence of pressure gradient on the structure,and distribution of cooling effectiveness on the blade surface.The numerical results show that cooling hole with curved passage could bring positive impact on the increase of the local cooling effectiveness.On the suction side,the increased cooling effectiveness could be about 82% and about 77% on the pressure side,compared to the conventional straight hole.展开更多
文摘A new two-dimensional （2D） analytical model for the threshold-voltage of fully depleted SOI MOSFETs is derived. The 2D potential distribution functions in the active layer of the devices are obtained through solving the 2D Poisson＇s equation. The minimum of the potential at the oxide-Si layer interface is used to monitor the threshold voltage of the SOI MOSFETs. This model is verified by its excellent agreement with MEDICI simulation using SOI MOSFETs with different gate lengths,gate oxide thicknesses,silicon film thicknesses,and channel doping concentrations.
文摘A novel approximation of the two-dimensional （2D） potential function perpendicular to the channel is proposed,and then an analytical threshold voltage model for a fully depleted SOI-MOSFET with a non-uniform Gaussian distribution doping profile is given based on this approximation. The model agrees well with numerical simulation by MEDICI. The result represents a new way and some reference points in analyzing and controlling the threshold voltage of non-uniform fully depleted （FD） SOI devices in practice.
基金supported by the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2015023)National Natural Science Foundation of China(81471784,51802115)+3 种基金Natural Science Foundation of Beijing(2172058)Natural Science Foundation of Shandong Province(ZR2018BEM010,ZR2019YQ21)Major Program of Shandong Province Natural Science Foundation(ZR2018ZC0843)Scientific and Technology Project of University of Jinan(XKY1923)~~
文摘Rapid technological development and population growth are responsible for a series of imminent environmental problems and an ineluctable energy crisis.The application of semiconductor nanomaterials in photocatalysis or photoelectrocatalysis(PEC)for either the degradation of contaminants in the environment or the generation of hydrogen as clean fuel is an effective approach to alleviate these problems.However,the efficiency of such processes remains suboptimal for real applications.Reasonable construction of a built-in electric field is considered to efficiently enhance carrier separation and reduce carrier recombination to improve catalytic performance.In the past decade,as a new method to enhance the built-in electric field,the piezoelectric effect from piezoelectric materials has been extensively studied.In this review,we provide an overview of the properties of piezoelectric materials and the mechanisms of piezoelectricity and ferroelectricity for a built-in electric field.Then,piezoelectric and ferroelectric polarization regulated built-in electric fields that mediate catalysis are discussed.Furthermore,the applications of piezoelectric semiconductor materials are also highlighted,including degradation of pollutants,bacteria disinfection,water splitting for H2 generation,and organic synthesis.We conclude by discussing the challenges in the field and the exciting opportunities to further improve piezo-catalytic efficiency.
基金The project supports by National Natural Science Foundation of China under Grant No. 40233033
文摘A simple barotropic potential vorticity equation with the influence of dissipation is applied to investigate the nonlinear Rossby wave in a shear flow in the tropical atmophere. By the reduetive perturbation method, we derive the rotational KdV （rKdV for short） equation. And then, with the help of Jaeobi elliptie functions, we obtain various periodic structures for these Rossby waves. It is shown that dissipation is very important for these periodic structures of rational form.
文摘A temperature-dependent model for threshold voltage and potential distribution of fully depleted silicon-on- insulator metal-oxide-semiconductor field-effect transistors is developed. The two-dimensional potential distribution function in the silicon thin film based on an approximate parabolic function has been applied to solve the two-dimensional Poisson＇s equation with suitable boundary conditions. The minimum of the surface potential is used to deduce the threshold voltage model. The model reveals the variations of potential distribution and threshold voltage with temperature, taking into account short-channel effects. Furthermore, the model is verified by the SILVACO ATLAS simulation. The calculations and the simulation agree well.
文摘A quasi two-dimensional （2D） analytical model of a double-gate （DG） MOSFET with Schottky source/drain is developed based on the Poisson equation.The 2D potential distribution in the channel is calculated.An expression for threshold voltage for a short-channel DG MOSFET with Schottky S/D is also presented by defining the turn-on condition.The results of the model are verified by the numerical simulator DESSIS-ISE.
文摘Unidirectional transport of a particle in a spatially periodic and symmetric potential under a periodic force with broken temporal symmetry is studied. With a collaboration of the potential field and the asymmetric ac force, a dc current can be observed. Resonant current steps are found for a finite period of the ac force. A phase diagram of these resonant steps is given. Stochastic-resonance-like directional transport induced by thermal noises is revealed.
文摘In this paper, we conduct research on the development trend of urbanization of the rural migrant workers from the perspectives of health and life stress. According to the theory of modern sociological about community, the migrant worker and city people’s relations belongs to typical in community’s relations with the outside community, among them not only isolates and repels psychologically mutually, but also has the direct conflicts of interest. This not only causes the migrant worker to suffer the prejudice and discrimination of city people, is hard to be a part of the city life, but also causes repellency urban institutional arrangements to disintegrate to a certain extent difficultly while the migrant worker is hard to enter in the urban system. Under this basis, this paper proposes the health and life stress assisted development trend of urbanization of the rural migrant workers basic research, the idea is new and innovative, in the later time we will apply it more.
文摘The analytical solutions to 1D Schrdinger equation (in depth direction) in double gate (DG) MOSFETs are derived to calculate electron density and threshold voltage.The non uniform potential in the channel is concerned with an arbitrary depth so that the analytical solutions agree well with numerical ones.Then,an implicit expression for electron density and a closed form of threshold voltage are presented fully comprising quantum mechanical (QM) effects.This model predicts an increased electron density with an increasing channel depth in subthreshold region or mild inversion region.However,it becomes independent on channel depth in strong inversion region,which is in accordance with numerical analysis.It is also concluded that the QM model,which barely considers a box like potential in the channel,slightly over predicts threshold voltage and underestimates electron density,and the error increases with an increasing channel depth or a decreasing gate oxide thickness.
基金Key foundation project of Yunnan province (2003D00142) Natural Science Foundation of China (40065001)
文摘Variance analysis, correlation analysis and regression analysis methods are applied to analyze the variation of circulation at 500 hPa. In winter, there are three regions (180°E – 150°W, 45°N – 60°N, 70°W – 100 °W,45°N – 75°N, 60°E – 100°E, 65°N – 80°N) whose variations are strong. Those regions are the key regions in which atmospheric circulation can change. Those regions are correlated to some teleconnections and can present a part of variations of 500 hPa to some degree. The linear contemporary correlation between those regions and the height at 500 hPa is significant. Those regions can account for 88 % of variations of concurrent height at 500 hPa. Those regions can present and forecast some variations to some degree in March and April. The longer the time interval, the worse the forecast effect will be. The interannual variations of Q1, Q2 and the SST are weak in the western Pacific.
文摘Trends in modern industry show a tendency towards demassovization of production as a response to the customers＇ specific needs for unique and personalized products. This provokes significant changes in the processes of manufacturing, assembly, and testing The cost of such a type of production can be reduced by employing highly productive reconfigurable equipment with proper software to enable optimization. This paper presents a decision support extension for directing of hydraulic cylinders to assembly-testing lines using fuzzy logic in the Enterprise Resource Planning system of a small size production in a factory in Bulgaria. Different assembly-testing lines are flexibly assigned to the specific cylinder＇s parameters by the developed fuzzy system on the basis of the overlapping of parameters in the hydraulic cylinders classification. The final decision on the line assigned in case of alternatives is made through accounting for the minimal cylinder delay time. The effectiveness of the approach is assessed by simulation. It leads to an increase of the efficiency of the assembly-testing flow lines, a reduction of the time needed for hydraulic cylinders assembling and testing and balanced loading of the modules.
基金supported by the National Natural Science Foundation of China (Grant No. 50876028)
文摘In order to assess the influences of curved hole passage on cooling effectiveness and flow structure of turbine blade leading edge,the detached eddy simulation is applied to numerically investigate the AGTB turbine cascade under the condition of global blowing ratio M=0.7.The straight or curved cooling holes are located at either the pressure or suction side near the leading edge.The analysis and discussion focus on the local turbulence structure;influence of pressure gradient on the structure,and distribution of cooling effectiveness on the blade surface.The numerical results show that cooling hole with curved passage could bring positive impact on the increase of the local cooling effectiveness.On the suction side,the increased cooling effectiveness could be about 82% and about 77% on the pressure side,compared to the conventional straight hole.
