The jet structure of the Southern Ocean front south of Australia is studied in stream-coordinate with a new altimeter product—Absolute Dynamic Topography (ADT) from AVISO. The accuracy of the ADT data is validated wi...The jet structure of the Southern Ocean front south of Australia is studied in stream-coordinate with a new altimeter product—Absolute Dynamic Topography (ADT) from AVISO. The accuracy of the ADT data is validated with the mooring data from a two-year subantarctic-front experiment. It is demonstrated that the ADT is consistent with in-situ measurements and captures the meso-scale activity of the Antarctic Circumpolar Current (ACC). Stream-coordinate analysis of ADT surface geostrophic flows finds that ACC jets exhibit large spatio-temporal variability and do not correspond to particular streamfunction values. In the circumpolar scope ACC jets display a transient fragmented pattern controlled by topographic features. The poleward shift of jet in streamfunction space, as revealed by a streamwise correlation method, indicates the presence of meridional fluxes of zonal momentum. Such cross-stream eddy fluxes concentrate the broad ACC baroclinic flow into narrow jets. Combined with a recent discovery of gravest empirical mode (GEM) in the thermohaline fields, the study clarifies the interrelationship among front, jet and streamfunction in the Southern Ocean.展开更多
Shunt resistance of solar cell must be monitored for large area solar cell manufactured with conventional process.A measuring method for the shunt resistance is derived from direct-current model.The shunt resistance o...Shunt resistance of solar cell must be monitored for large area solar cell manufactured with conventional process.A measuring method for the shunt resistance is derived from direct-current model.The shunt resistance of solar cell is obtained only by treating a part of I-V data.展开更多
In view of the universality of the parallel connection of solar cells and their mismatch problem, in the present paper, we select two shunt solar cells (connected in parallel) as our research object, and use the equiv...In view of the universality of the parallel connection of solar cells and their mismatch problem, in the present paper, we select two shunt solar cells (connected in parallel) as our research object, and use the equivalent one-diode circuit of the solar cell and the analysis of the two-body model. At first, the equations of current and voltage are deduced from the related electrical laws and the circuit diagram of the two solar cells connected in parallel. Then, according to the experimentally measured data of typical single-crystalline silicon solar cells (125 mm×125 mm), we select the appropriate simulation parameters. Following this, by using the photo-generated current, the shunt resistance, and the serial resistance of one of the shunt solar cells and the load resistance as independent variables, in turn, the changing characteristics of each branch current in the two shunt solar cells are numerically discussed and analyzed for these four cases for the first time. At the same time, we provide a simple physical explanation for the modeling results. Our analyses show that these parameters have different impacts on the internal currents of solar cells connected in parallel. These results provide a reference to solve the problem of connecting solar cells and to develop higher efficiency solar cells and systems. Meanwhile, the results will contribute to a better comprehension of the reasons for efficiency loss of solar cells and systems, and deepen the understanding of the electrical of solar cells behavior for high performance photovoltaic applications.展开更多
This paper reviews differences between the deterministic(sharp and diffuse)and statistical models of the interphase region between the two-phases.In the literature this region is usually referred to as the(macroscopic...This paper reviews differences between the deterministic(sharp and diffuse)and statistical models of the interphase region between the two-phases.In the literature this region is usually referred to as the(macroscopic)interface.Therein,the mesoscopic interface that is defined at the molecular level and agitated by the thermal fluctuations is found with nonzero probability.For this reason,in this work,the interphase region is called the mesoscopic intermittency/transition region.To this purpose,the first part of the present work gives the rationale for introduction of the mesoscopic intermittency region statistical model.It is argued that classical(deterministic)sharp and diffuse models do not explain the experimental and numerical results presented in the literature.Afterwards,it is elucidated that a statistical model of the mesoscopic intermittency region(SMIR)combines existing sharp and diffuse models into a single coherent framework and explains published experimental and numerical results.In the second part of the present paper,the SMIR is used for the first time to predict equilibrium and nonequilibrium two-phase flow in the numerical simulation.To this goal,a two-dimensional rising gas bubble is studied;obtained numerical results are used as a basis to discuss differences between the deterministic and statistical models showing the statistical description has a potential to account for the physical phenomena not previously considered in the computer simulations.展开更多
基金Supported by the National Basic Research Program of China (973 Program) (Nos.2006CB403601,2007CB411804)the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX2-YW-Q11-02)the National Natural Sciences Foundation of China (No.40776014)
文摘The jet structure of the Southern Ocean front south of Australia is studied in stream-coordinate with a new altimeter product—Absolute Dynamic Topography (ADT) from AVISO. The accuracy of the ADT data is validated with the mooring data from a two-year subantarctic-front experiment. It is demonstrated that the ADT is consistent with in-situ measurements and captures the meso-scale activity of the Antarctic Circumpolar Current (ACC). Stream-coordinate analysis of ADT surface geostrophic flows finds that ACC jets exhibit large spatio-temporal variability and do not correspond to particular streamfunction values. In the circumpolar scope ACC jets display a transient fragmented pattern controlled by topographic features. The poleward shift of jet in streamfunction space, as revealed by a streamwise correlation method, indicates the presence of meridional fluxes of zonal momentum. Such cross-stream eddy fluxes concentrate the broad ACC baroclinic flow into narrow jets. Combined with a recent discovery of gravest empirical mode (GEM) in the thermohaline fields, the study clarifies the interrelationship among front, jet and streamfunction in the Southern Ocean.
文摘Shunt resistance of solar cell must be monitored for large area solar cell manufactured with conventional process.A measuring method for the shunt resistance is derived from direct-current model.The shunt resistance of solar cell is obtained only by treating a part of I-V data.
基金supported by the National Natural Science Foundation of China (Grant No. 51561031)the Natural Science Foundation of Guangxi Province (Grant No. 2015GXNSFBA139240)+1 种基金Open Foundation of Guangxi Colleges and Universities Key Laboratory of Complex System Optimization and Large Data Processing (Grant No. 2015CSOBD0102)the Highlevel Personnel Scientific Research Funds of Yulin Normal University (Grant No. G20150001)
文摘In view of the universality of the parallel connection of solar cells and their mismatch problem, in the present paper, we select two shunt solar cells (connected in parallel) as our research object, and use the equivalent one-diode circuit of the solar cell and the analysis of the two-body model. At first, the equations of current and voltage are deduced from the related electrical laws and the circuit diagram of the two solar cells connected in parallel. Then, according to the experimentally measured data of typical single-crystalline silicon solar cells (125 mm×125 mm), we select the appropriate simulation parameters. Following this, by using the photo-generated current, the shunt resistance, and the serial resistance of one of the shunt solar cells and the load resistance as independent variables, in turn, the changing characteristics of each branch current in the two shunt solar cells are numerically discussed and analyzed for these four cases for the first time. At the same time, we provide a simple physical explanation for the modeling results. Our analyses show that these parameters have different impacts on the internal currents of solar cells connected in parallel. These results provide a reference to solve the problem of connecting solar cells and to develop higher efficiency solar cells and systems. Meanwhile, the results will contribute to a better comprehension of the reasons for efficiency loss of solar cells and systems, and deepen the understanding of the electrical of solar cells behavior for high performance photovoltaic applications.
基金This work was supported by the National Science Center,Poland(Narodowe Centrum Nauki,Polska)in the project“Statistical modeling of turbulent two-fluid flows with interfaces”(Grant No.2016/21/B/ST8/01010,ID:334165).
文摘This paper reviews differences between the deterministic(sharp and diffuse)and statistical models of the interphase region between the two-phases.In the literature this region is usually referred to as the(macroscopic)interface.Therein,the mesoscopic interface that is defined at the molecular level and agitated by the thermal fluctuations is found with nonzero probability.For this reason,in this work,the interphase region is called the mesoscopic intermittency/transition region.To this purpose,the first part of the present work gives the rationale for introduction of the mesoscopic intermittency region statistical model.It is argued that classical(deterministic)sharp and diffuse models do not explain the experimental and numerical results presented in the literature.Afterwards,it is elucidated that a statistical model of the mesoscopic intermittency region(SMIR)combines existing sharp and diffuse models into a single coherent framework and explains published experimental and numerical results.In the second part of the present paper,the SMIR is used for the first time to predict equilibrium and nonequilibrium two-phase flow in the numerical simulation.To this goal,a two-dimensional rising gas bubble is studied;obtained numerical results are used as a basis to discuss differences between the deterministic and statistical models showing the statistical description has a potential to account for the physical phenomena not previously considered in the computer simulations.