Based on transient temperature field theory of heat conduction, the solar temperature field calculation model of U-shape sectioned high-speed railway cable-stayed bridge under actions of concrete beams and ballast was...Based on transient temperature field theory of heat conduction, the solar temperature field calculation model of U-shape sectioned high-speed railway cable-stayed bridge under actions of concrete beams and ballast was established. Using parametric programming language, finite element calculation modules considering climate conditions, bridge site, structure dimension and material thermophysical properties were compiled. Six standard day cycles with the strongest yearly radiation among the bridge sites were selected for sectional solar temperature field calculation and temperature distributions under different temperature-sensitive parameters were compared. The results show that under the influence of sunshine, U-shape section of the beam shows obvious nonlinear distribution characteristics and the maximum cross-section temperature difference is more than 21℃; the ballast significantly reduces sunshine temperature difference of the beam and temperature peak of the bottom margin lags with the increase of ballast thickness; the maximum cross-section vertical temperature gradient appears in summer while large transverse temperature difference appears in winter.展开更多
In order to improve the service life of solar street lamp, it is necessary to manage the lamp＇s battery in the form of on-line detection via wireless communanication. A wireless managonent systean for solar street la...In order to improve the service life of solar street lamp, it is necessary to manage the lamp＇s battery in the form of on-line detection via wireless communanication. A wireless managonent systean for solar street lamp based on nanoLOC AVR nttlule is researched in this paper, the system can real-timely detect the solar street lamp＇s battery voltage, corrent, tonperature, internal resistance, residual capacity and so on. And the collected data is transmitted to computer＇ s management via wireless connnunication to achieve recording, storage, analysis and processing for various parameters.展开更多
The atmosphere protects humans, plants, ani- mals, and microorganisms from damaging doses of ultra- violet-B （UVB） solar radiation （280-320 nm） because it modifies the UVB reaching the Earth＇s surface. This modif...The atmosphere protects humans, plants, ani- mals, and microorganisms from damaging doses of ultra- violet-B （UVB） solar radiation （280-320 nm） because it modifies the UVB reaching the Earth＇s surface. This modification is a function of the solar radiation＇s path length through the atmosphere and the amount of each attenuator along the path length. The path length is deter- mined by solar zenith angle （SZA）. The present work ex- plains the dependence of hemispherical transmittance of UVB on SZA. The database used consists of five years of hourly UVB and global solar radiation measurements. From 2001 to 2005, the South Valley University （SVU） meteorological research station （26.20°N, 32.75°E） car- ried out these measurements on a horizontal surface. In addition, the corresponding extraterrestrial UVB （UVBe^d and broadband solar radiation （Gext） were estimated. Consequently, the hemispherical transmittance of UVB （KtuvB） and the hemispherical transmittance of global solar radiation （Kt） were estimated. Furthermore, the UVB redaction due to the atmosphere was evaluated. An analy- sis of the dependence between KtuvB and SZA at different ranges of Kt was performed. A functional dependence between KtuvB and SZA （KtuvB=-a（SZA）＋b） for very narrow Kt-ranges （width of ranges was 0.01） was devel- oped. The results are discussed, and the sensitivity of AKtuvB to △SZA for very narrow Kt-ranges was studied. It was found that the sensitivity of △KtUVB to ASZA slightly increases with increased Kt, which means KtuvB is sensi- tive to SZA as Kt increases. The maximum correlation （R） between KtuvB and SZA was equal to -0.83 for Kt= 0.76.展开更多
This paper uses Abductive network to predict global solar radiation in any location in the Kingdom of Saudi Arabia （KSA） based on sunshine duration, month number, latitude, longitude, and altitude of the location. R...This paper uses Abductive network to predict global solar radiation in any location in the Kingdom of Saudi Arabia （KSA） based on sunshine duration, month number, latitude, longitude, and altitude of the location. Results indicate good agreement between measured and predicted GSR values for each of the 35 locations with known GSR values. Finally, the data from all available stations are used to train an abductive network to estimate the GSR values anywhere in the Kingdom based on latitude and longitude. GSR values are estimated using the developed method at 25 additional locations throughout the kingdom and used with the measured data from the 35 available measurement stations to draw a comprehensive contour map of GSR values for KSA.展开更多
Taking the ecological, environmental protection as the starting point, in view of our country road lighting with excessive power consumption problems, the paper proposes design scheme of S type spiral lamp that is sui...Taking the ecological, environmental protection as the starting point, in view of our country road lighting with excessive power consumption problems, the paper proposes design scheme of S type spiral lamp that is suitable the coastal city, highway zone by solar energy combined with wind energy generation. This design uses class of S spiral with the highest wind energy utilization rate, and the surface has materials that can absorb solar energy, its structure built in simple and the design fit standard proportion lamp. This design has the advantages of beautiful apnearance, easv to produce, has the very big use value.展开更多
The effect of the parameters on the open-circuit voltage, V_(OC) of a-Si:H/c-Si heterojunction solar cells was explored by an analytical model. The analytical results show that V_(OC) increases linearly with the logar...The effect of the parameters on the open-circuit voltage, V_(OC) of a-Si:H/c-Si heterojunction solar cells was explored by an analytical model. The analytical results show that V_(OC) increases linearly with the logarithm of illumination intensity under usual illumination. There are two critical values of the interface state density(D_(it)) for the open-circuit voltage(V_(OC)), D_(it)^(crit,1) and D_(it)crit,2(a few 1010 cm^(-2)·e V^(-1)). V_(OC) decreases remarkably when D_(it) is higher than D_(it)^(crit,1). To achieve high V_(OC), the interface states should reduce down to a few 1010 cm^(-2)·e V^(-1). Due to the difference between the effective density of states in the conduction and valence band edges of c-Si, the open-circuit voltage of a-Si:H/c-Si heterojunction cells fabricated on n-type c-Si wafers is about 22 mV higher than that fabricated on p-type c-Si wafers at the same case. V_(OC) decreases with decreasing the a-Si:H doping concentration at low doping level since the electric field over the c-Si depletion region is reduced at low doping level. Therefore, the a-Si:H layer should be doped higher than a critical value of 5×10^(18) cm^(-3) to achieve high V_(OC).展开更多
In a smart grid, electric loads are supplied by various DC （direct current） power sources, such as solar cells or batteries. On the other hand, traditional AC （alternating current） loads like a directly connected ...In a smart grid, electric loads are supplied by various DC （direct current） power sources, such as solar cells or batteries. On the other hand, traditional AC （alternating current） loads like a directly connected induction motors will also be used. In the circumstances, a smart power conversion unit is one of key components, which can integrate these DC or AC apparatus and trade power among them. Authors have developed an integrated power converter based on a well-known circuit topology of flying capacitor multilevel converter. This paper describes the detail of the circuit topology and its characteristics depending on designed parameters. The achieved power quality is also verified by simulation study.展开更多
The dependence of the organic solar cells parameters, e.g., the shirt circuit current Isc, open circuit voltage Vo,., the fill factor FF and the efficiency eta on temperature is investigated. By expressing the differe...The dependence of the organic solar cells parameters, e.g., the shirt circuit current Isc, open circuit voltage Vo,., the fill factor FF and the efficiency eta on temperature is investigated. By expressing the different equations which link the parameters with temperature, it is observed that the short circuit current Isc increases so monotonous with temperature and then saturates to a maximum value before decreasing at high temperatures. The open circuit voltage V∝ decreases linearly with the increasing of the temperature. The fill factor FF and the efficiency eta which are directly related with short circuit current Isc and the open circuit voltage V∝ follow their variations.展开更多
基金Project(51378503)supported by the National Natural Science Foundation of ChinaProject(2010G018-A-3)supported by Technology Research and Development Program of the Ministry of Railways,China
文摘Based on transient temperature field theory of heat conduction, the solar temperature field calculation model of U-shape sectioned high-speed railway cable-stayed bridge under actions of concrete beams and ballast was established. Using parametric programming language, finite element calculation modules considering climate conditions, bridge site, structure dimension and material thermophysical properties were compiled. Six standard day cycles with the strongest yearly radiation among the bridge sites were selected for sectional solar temperature field calculation and temperature distributions under different temperature-sensitive parameters were compared. The results show that under the influence of sunshine, U-shape section of the beam shows obvious nonlinear distribution characteristics and the maximum cross-section temperature difference is more than 21℃; the ballast significantly reduces sunshine temperature difference of the beam and temperature peak of the bottom margin lags with the increase of ballast thickness; the maximum cross-section vertical temperature gradient appears in summer while large transverse temperature difference appears in winter.
文摘In order to improve the service life of solar street lamp, it is necessary to manage the lamp＇s battery in the form of on-line detection via wireless communanication. A wireless managonent systean for solar street lamp based on nanoLOC AVR nttlule is researched in this paper, the system can real-timely detect the solar street lamp＇s battery voltage, corrent, tonperature, internal resistance, residual capacity and so on. And the collected data is transmitted to computer＇ s management via wireless connnunication to achieve recording, storage, analysis and processing for various parameters.
基金supported by the Deanship of Scientific Research from King Saud University
文摘The atmosphere protects humans, plants, ani- mals, and microorganisms from damaging doses of ultra- violet-B （UVB） solar radiation （280-320 nm） because it modifies the UVB reaching the Earth＇s surface. This modification is a function of the solar radiation＇s path length through the atmosphere and the amount of each attenuator along the path length. The path length is deter- mined by solar zenith angle （SZA）. The present work ex- plains the dependence of hemispherical transmittance of UVB on SZA. The database used consists of five years of hourly UVB and global solar radiation measurements. From 2001 to 2005, the South Valley University （SVU） meteorological research station （26.20°N, 32.75°E） car- ried out these measurements on a horizontal surface. In addition, the corresponding extraterrestrial UVB （UVBe^d and broadband solar radiation （Gext） were estimated. Consequently, the hemispherical transmittance of UVB （KtuvB） and the hemispherical transmittance of global solar radiation （Kt） were estimated. Furthermore, the UVB redaction due to the atmosphere was evaluated. An analy- sis of the dependence between KtuvB and SZA at different ranges of Kt was performed. A functional dependence between KtuvB and SZA （KtuvB=-a（SZA）＋b） for very narrow Kt-ranges （width of ranges was 0.01） was devel- oped. The results are discussed, and the sensitivity of AKtuvB to △SZA for very narrow Kt-ranges was studied. It was found that the sensitivity of △KtUVB to ASZA slightly increases with increased Kt, which means KtuvB is sensi- tive to SZA as Kt increases. The maximum correlation （R） between KtuvB and SZA was equal to -0.83 for Kt= 0.76.
文摘This paper uses Abductive network to predict global solar radiation in any location in the Kingdom of Saudi Arabia （KSA） based on sunshine duration, month number, latitude, longitude, and altitude of the location. Results indicate good agreement between measured and predicted GSR values for each of the 35 locations with known GSR values. Finally, the data from all available stations are used to train an abductive network to estimate the GSR values anywhere in the Kingdom based on latitude and longitude. GSR values are estimated using the developed method at 25 additional locations throughout the kingdom and used with the measured data from the 35 available measurement stations to draw a comprehensive contour map of GSR values for KSA.
文摘Taking the ecological, environmental protection as the starting point, in view of our country road lighting with excessive power consumption problems, the paper proposes design scheme of S type spiral lamp that is suitable the coastal city, highway zone by solar energy combined with wind energy generation. This design uses class of S spiral with the highest wind energy utilization rate, and the surface has materials that can absorb solar energy, its structure built in simple and the design fit standard proportion lamp. This design has the advantages of beautiful apnearance, easv to produce, has the very big use value.
基金Project(11374094)supported by the National Natural Science Foundation of ChinaProject(2013HZX23)supported by Natural Science Foundation of Hunan University of Technology,ChinaProject(2015JJ3060)supported by Natural Science Foundation of Hunan Province of China
文摘The effect of the parameters on the open-circuit voltage, V_(OC) of a-Si:H/c-Si heterojunction solar cells was explored by an analytical model. The analytical results show that V_(OC) increases linearly with the logarithm of illumination intensity under usual illumination. There are two critical values of the interface state density(D_(it)) for the open-circuit voltage(V_(OC)), D_(it)^(crit,1) and D_(it)crit,2(a few 1010 cm^(-2)·e V^(-1)). V_(OC) decreases remarkably when D_(it) is higher than D_(it)^(crit,1). To achieve high V_(OC), the interface states should reduce down to a few 1010 cm^(-2)·e V^(-1). Due to the difference between the effective density of states in the conduction and valence band edges of c-Si, the open-circuit voltage of a-Si:H/c-Si heterojunction cells fabricated on n-type c-Si wafers is about 22 mV higher than that fabricated on p-type c-Si wafers at the same case. V_(OC) decreases with decreasing the a-Si:H doping concentration at low doping level since the electric field over the c-Si depletion region is reduced at low doping level. Therefore, the a-Si:H layer should be doped higher than a critical value of 5×10^(18) cm^(-3) to achieve high V_(OC).
文摘In a smart grid, electric loads are supplied by various DC （direct current） power sources, such as solar cells or batteries. On the other hand, traditional AC （alternating current） loads like a directly connected induction motors will also be used. In the circumstances, a smart power conversion unit is one of key components, which can integrate these DC or AC apparatus and trade power among them. Authors have developed an integrated power converter based on a well-known circuit topology of flying capacitor multilevel converter. This paper describes the detail of the circuit topology and its characteristics depending on designed parameters. The achieved power quality is also verified by simulation study.
文摘The dependence of the organic solar cells parameters, e.g., the shirt circuit current Isc, open circuit voltage Vo,., the fill factor FF and the efficiency eta on temperature is investigated. By expressing the different equations which link the parameters with temperature, it is observed that the short circuit current Isc increases so monotonous with temperature and then saturates to a maximum value before decreasing at high temperatures. The open circuit voltage V∝ decreases linearly with the increasing of the temperature. The fill factor FF and the efficiency eta which are directly related with short circuit current Isc and the open circuit voltage V∝ follow their variations.
