This study investigates the effect of the magnetic field on the transient density of excess minority charge carriers in the base of a series-connected vertical junction silicon solar cell. The solar cell is presented ...This study investigates the effect of the magnetic field on the transient density of excess minority charge carriers in the base of a series-connected vertical junction silicon solar cell. The solar cell is presented in open circuit transient operation. The magnetic field through the Laplace force which deflects the photogenerated carriers from their initial trajectory towards the lateral surfaces reducing their mobility, diffusion and conduction, will certainly influence the decay time of the transient regime. The transient density of excess minority carriers in the base is a sum of infinite terms whose decay time of the different harmonics is studied.展开更多
In this paper,for 1<p<∞,the authors show that the coarse l^(p)-Novikov conjecture holds for metric spaces with bounded geometry which are coarsely embeddable into a Banach space with Kasparov-Yu’s Property(H).
Background: Coarse woody debris(CWD) is very important for forest ecosystems, particularly for biodiversity and carbon storage. Its relevance as a possible reservoir and source of nutrients is less clear, especially i...Background: Coarse woody debris(CWD) is very important for forest ecosystems, particularly for biodiversity and carbon storage. Its relevance as a possible reservoir and source of nutrients is less clear, especially in central Europe.Methods: Based on a chronosequence of known ages of logs, we analyzed the nutrients stored in CWD of Fagus sylvatica, Picea abies, and Pinus sylvestris at different sites in Germany. To quantify nutrient concentrations, we assessed the use of Near Infrared Reflectance Spectroscopy(NIRS) to determine the chemical properties of CWD.Results: NIRS models were suitable to predict concentrations of C, N, P, lignin and extractives. Concentrations of most nutrients increased with mass loss, with the exception of potassium, which decreased for beech and pine and remained relatively constant for spruce. The highest nutrient concentrations(N, P, S, Ca and Mn, except Mg and K) were generally observed in highly decomposed spruce logs. The net effect of decreasing CWD mass and increasing nutrient concentrations was either a decreasing(N, P and K in beech; P, Mg, K and Mn in pine), constant(S, Ca and Mg in beech; N, S and Ca in pine) or increasing amount of nutrients(N, P, S and Ca in spruce; Mn in beech) in the logsover the course of decomposition. The C/N ratio decreased for all tree species, most markedly for spruce from ca. 1000 at the beginning of the decomposition process to 180 at 36 years. The N/P ratio converged to a value of about 30 forall three species. Lignin concentrations increased for spruce and beech and remained constant for pine.Conclusions: Our results indicate that most nutrients remain in CWD for long periods. Nutrients may be used and cycled by microorganisms within CWD, but with the exception of P(in beech), Mg(in pine) and K(in beech and pine), there appears to be little net nutrient export until two thirds of the mass is lost. Instead, N, P, S and Ca were accumulated in spruce logs, indicating that CWD became a net sink rather than a net source of some nutrients for several decades.展开更多
The initial value problem(IVP)for the one-dimensional isentropic compressible Navier-Stokes-Poisson(CNSP)system is considered in this paper.For the variables,the electric field and the velocity,under the Lagrange coor...The initial value problem(IVP)for the one-dimensional isentropic compressible Navier-Stokes-Poisson(CNSP)system is considered in this paper.For the variables,the electric field and the velocity,under the Lagrange coordinate,we establish the global existence and uniqueness of the classical solutions to this IVP problem.Then we prove by the method of complex analysis,that the solutions to this system converge to those of the corresponding linearized system in the L^(2) norm as time tends to infinity.In addition,we show,using Green’s function,that the solutions to this system are close to a diffusion profile,pointwisely,as time goes to infinity.展开更多
The precise L^(p) norm of a class of Forelli-Rudin type operators on the Siegel upper half space is given in this paper.The main result not only implies the upper L^(p) norm estimate of the Bergman projection,but also...The precise L^(p) norm of a class of Forelli-Rudin type operators on the Siegel upper half space is given in this paper.The main result not only implies the upper L^(p) norm estimate of the Bergman projection,but also implies the precise L^(p) norm of the Berezin transform.展开更多
基金Supported by the Natural Science Foundation of Anhui Provincia Education Department(KJ2017A341)the Talent Project of Fuyang Normal University(RCXM201714)+1 种基金the second author is supported by the Natural Science Foundation of Anhui Province of China(1608085MA03)the Fundamental Research Funds of Tongling Xueyuan Rencai Program(2015TLXYRC09)
文摘This study investigates the effect of the magnetic field on the transient density of excess minority charge carriers in the base of a series-connected vertical junction silicon solar cell. The solar cell is presented in open circuit transient operation. The magnetic field through the Laplace force which deflects the photogenerated carriers from their initial trajectory towards the lateral surfaces reducing their mobility, diffusion and conduction, will certainly influence the decay time of the transient regime. The transient density of excess minority carriers in the base is a sum of infinite terms whose decay time of the different harmonics is studied.
基金supported by the National Natural Science Foundation of China(Nos.12171156)the Science and Technology Commission of Shanghai Municipality(No.22DZ2229014)。
文摘In this paper,for 1<p<∞,the authors show that the coarse l^(p)-Novikov conjecture holds for metric spaces with bounded geometry which are coarsely embeddable into a Banach space with Kasparov-Yu’s Property(H).
基金funded through a grant by the German Science Foundation(DFG-BA 2821/4-1)to J.Bauhus
文摘Background: Coarse woody debris(CWD) is very important for forest ecosystems, particularly for biodiversity and carbon storage. Its relevance as a possible reservoir and source of nutrients is less clear, especially in central Europe.Methods: Based on a chronosequence of known ages of logs, we analyzed the nutrients stored in CWD of Fagus sylvatica, Picea abies, and Pinus sylvestris at different sites in Germany. To quantify nutrient concentrations, we assessed the use of Near Infrared Reflectance Spectroscopy(NIRS) to determine the chemical properties of CWD.Results: NIRS models were suitable to predict concentrations of C, N, P, lignin and extractives. Concentrations of most nutrients increased with mass loss, with the exception of potassium, which decreased for beech and pine and remained relatively constant for spruce. The highest nutrient concentrations(N, P, S, Ca and Mn, except Mg and K) were generally observed in highly decomposed spruce logs. The net effect of decreasing CWD mass and increasing nutrient concentrations was either a decreasing(N, P and K in beech; P, Mg, K and Mn in pine), constant(S, Ca and Mg in beech; N, S and Ca in pine) or increasing amount of nutrients(N, P, S and Ca in spruce; Mn in beech) in the logsover the course of decomposition. The C/N ratio decreased for all tree species, most markedly for spruce from ca. 1000 at the beginning of the decomposition process to 180 at 36 years. The N/P ratio converged to a value of about 30 forall three species. Lignin concentrations increased for spruce and beech and remained constant for pine.Conclusions: Our results indicate that most nutrients remain in CWD for long periods. Nutrients may be used and cycled by microorganisms within CWD, but with the exception of P(in beech), Mg(in pine) and K(in beech and pine), there appears to be little net nutrient export until two thirds of the mass is lost. Instead, N, P, S and Ca were accumulated in spruce logs, indicating that CWD became a net sink rather than a net source of some nutrients for several decades.
基金supported by National Natural Science Foundation of China(11931010,11671384,11871047 and 12101372)by the key research project of Academy for Multidisciplinary Studies,Capital Normal Universityby the Capacity Building for Sci-Tech Innovation-Fundamental Scientific Research Funds(007/20530290068).
文摘The initial value problem(IVP)for the one-dimensional isentropic compressible Navier-Stokes-Poisson(CNSP)system is considered in this paper.For the variables,the electric field and the velocity,under the Lagrange coordinate,we establish the global existence and uniqueness of the classical solutions to this IVP problem.Then we prove by the method of complex analysis,that the solutions to this system converge to those of the corresponding linearized system in the L^(2) norm as time tends to infinity.In addition,we show,using Green’s function,that the solutions to this system are close to a diffusion profile,pointwisely,as time goes to infinity.
基金supported by the National Natural Science Foundation of China(11801172,11771139,12071130)supported by the Natural Science Foundation of Zhejiang Province(LQ21A010002)supported by the Natural Science Foundation of Zhejiang Province(LY20A010007).
文摘The precise L^(p) norm of a class of Forelli-Rudin type operators on the Siegel upper half space is given in this paper.The main result not only implies the upper L^(p) norm estimate of the Bergman projection,but also implies the precise L^(p) norm of the Berezin transform.
