马铃薯高垄膜上覆土自然顶膜出苗栽培技术为近年来推广的一项马铃薯栽培新技术,具有自然出苗率高、产量高、杂草少等优点,其中膜上覆土厚度是影响马铃薯自然顶膜出苗的关键因素之一。为了确定马铃薯最佳覆土厚度,试验设0、1、3、5、7 c...马铃薯高垄膜上覆土自然顶膜出苗栽培技术为近年来推广的一项马铃薯栽培新技术,具有自然出苗率高、产量高、杂草少等优点,其中膜上覆土厚度是影响马铃薯自然顶膜出苗的关键因素之一。为了确定马铃薯最佳覆土厚度,试验设0、1、3、5、7 cm 5个覆土厚度处理,结果表明:3、5 cm 2个处理为最佳覆土厚度,更有利于顶膜出苗,自然顶膜出苗率分别达到95.2%、98%,出苗整齐度分别为91.7%、91.4%,较对照产量分别增加了28.83%、27.72%,商品率分别提高了47.77%、49.64%,膜下杂草分别减少了44.74%、84.21%。同时,地膜回收也更为彻底。展开更多
By solving the magneto-transport equation for excess minority charge carriers in the base of the series vertical-junction silicon cell, the phenomenological parameters of the cell can be determined from the boundary c...By solving the magneto-transport equation for excess minority charge carriers in the base of the series vertical-junction silicon cell, the phenomenological parameters of the cell can be determined from the boundary conditions. Photocurrent density and photovoltage are determined for each value of applied magnetic field and corresponding optimum thickness, to establish the current-voltage characteristic (Jph(Sf, Sb, z, B, Hop)-Vph(Sf, Sb, z, B, Hop) of the silicon cell under polychromatic illumination. This study will make it possible to reduce the material used (by reducing the optimum thickness), which will help to lower prices. It will also enable us to reduce betting effects (lower series resistance), thereby boosting solar cell efficiency.展开更多
The bifacial silicon solar cell, placed at temperature (T) and illuminated from the back side by monochromatic light in frequency modulation (ω), is studied from the frequency dynamic diffusion equation, relative to ...The bifacial silicon solar cell, placed at temperature (T) and illuminated from the back side by monochromatic light in frequency modulation (ω), is studied from the frequency dynamic diffusion equation, relative to the density of excess minority carriers in the base. The expressions of the dynamic recombination velocities of the minority carriers on the rear side of the base Sb1(D(ω, T);H) and Sb2(α, D(ω, T);H), are analyzed as a function of the dynamic diffusion coefficient (D(ω, T)), the absorption coefficient (α(λ)) and the thickness of the base (H). Thus their graphic representation makes it possible to go up, to the base optimum thickness (Hopt(ω, T)), for different temperature values and frequency ranges of modulation of monochromatic light, of strong penetration. The base optimum thickness (Hopt(ω, T)) decreases with temperature, regardless of the frequency range and allows the realization of the solar cell with few material (Si).展开更多
The monochromatic absorption coefficient of silicon, inducing the light penetration depth into the base of the solar cell, is used to determine the optimum thickness necessary for the production of a large photocurren...The monochromatic absorption coefficient of silicon, inducing the light penetration depth into the base of the solar cell, is used to determine the optimum thickness necessary for the production of a large photocurrent. The absorption-generation-diffusion and recombination (bulk and surface) phenomena are taken into account in the excess minority carrier continuity equation. The solution of this equation gives the photocurrent according to ab</span><span style="font-family:Verdana;">sorption and electronic parameters. Then from the obtained short circuit</span><span style="font-family:Verdana;"> photocurrent expression, excess minority carrier back surface recombination velocity is determined, function of the monochromatic absorption coefficient at a given wavelength. This latter plotted versus base thickness yields the optimum thickness of an n</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">-p-p</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;"> solar cell, for each wavelength, which is in the range close to the energy band gap of the silicon material. This study provides a tool for improvement solar cell manufacture processes, through the mathematical relationship obtained from the thickness limit according to the absorption coefficient that allows base width optimization.展开更多
文摘马铃薯高垄膜上覆土自然顶膜出苗栽培技术为近年来推广的一项马铃薯栽培新技术,具有自然出苗率高、产量高、杂草少等优点,其中膜上覆土厚度是影响马铃薯自然顶膜出苗的关键因素之一。为了确定马铃薯最佳覆土厚度,试验设0、1、3、5、7 cm 5个覆土厚度处理,结果表明:3、5 cm 2个处理为最佳覆土厚度,更有利于顶膜出苗,自然顶膜出苗率分别达到95.2%、98%,出苗整齐度分别为91.7%、91.4%,较对照产量分别增加了28.83%、27.72%,商品率分别提高了47.77%、49.64%,膜下杂草分别减少了44.74%、84.21%。同时,地膜回收也更为彻底。
文摘By solving the magneto-transport equation for excess minority charge carriers in the base of the series vertical-junction silicon cell, the phenomenological parameters of the cell can be determined from the boundary conditions. Photocurrent density and photovoltage are determined for each value of applied magnetic field and corresponding optimum thickness, to establish the current-voltage characteristic (Jph(Sf, Sb, z, B, Hop)-Vph(Sf, Sb, z, B, Hop) of the silicon cell under polychromatic illumination. This study will make it possible to reduce the material used (by reducing the optimum thickness), which will help to lower prices. It will also enable us to reduce betting effects (lower series resistance), thereby boosting solar cell efficiency.
文摘The bifacial silicon solar cell, placed at temperature (T) and illuminated from the back side by monochromatic light in frequency modulation (ω), is studied from the frequency dynamic diffusion equation, relative to the density of excess minority carriers in the base. The expressions of the dynamic recombination velocities of the minority carriers on the rear side of the base Sb1(D(ω, T);H) and Sb2(α, D(ω, T);H), are analyzed as a function of the dynamic diffusion coefficient (D(ω, T)), the absorption coefficient (α(λ)) and the thickness of the base (H). Thus their graphic representation makes it possible to go up, to the base optimum thickness (Hopt(ω, T)), for different temperature values and frequency ranges of modulation of monochromatic light, of strong penetration. The base optimum thickness (Hopt(ω, T)) decreases with temperature, regardless of the frequency range and allows the realization of the solar cell with few material (Si).
文摘The monochromatic absorption coefficient of silicon, inducing the light penetration depth into the base of the solar cell, is used to determine the optimum thickness necessary for the production of a large photocurrent. The absorption-generation-diffusion and recombination (bulk and surface) phenomena are taken into account in the excess minority carrier continuity equation. The solution of this equation gives the photocurrent according to ab</span><span style="font-family:Verdana;">sorption and electronic parameters. Then from the obtained short circuit</span><span style="font-family:Verdana;"> photocurrent expression, excess minority carrier back surface recombination velocity is determined, function of the monochromatic absorption coefficient at a given wavelength. This latter plotted versus base thickness yields the optimum thickness of an n</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;">-p-p</span><sup><span style="font-family:Verdana;">+</span></sup><span style="font-family:Verdana;"> solar cell, for each wavelength, which is in the range close to the energy band gap of the silicon material. This study provides a tool for improvement solar cell manufacture processes, through the mathematical relationship obtained from the thickness limit according to the absorption coefficient that allows base width optimization.
