The novel CuO-SnO2 nanocomposite oxide photocatalysts were prepared by simple co-precipitation method, and characterized by X- ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurement an...The novel CuO-SnO2 nanocomposite oxide photocatalysts were prepared by simple co-precipitation method, and characterized by X- ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurement and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activities of CuO-SnO2, evaluated using the photodegradation of Acid Blue 62 as a probe reaction under the irradiation of Xenon light, were also found to be related to the calcination temperature and the molar ratio of Cu to Sn. The maximum photocatalytic activity of the CuO-SnO2 photocatalyst was observed to be calcined at 500~C for 3 h (the molar ratio of Cu to Sn was 1:1) due to the sample with good crystallization and high surface area. It also showed much higher photocatalytic activity in treatment dye wastewater under simulated sunlight irradiation compared to Degussa P25 TiO2.展开更多
CuO was synthesized by thermal decomposition of Cu(NO3)2·3H2O at various temperatures and characterized by powder X-ray diffractometry(XRD) as well as scanning electron microscopy(SEM).The effects of calcination ...CuO was synthesized by thermal decomposition of Cu(NO3)2·3H2O at various temperatures and characterized by powder X-ray diffractometry(XRD) as well as scanning electron microscopy(SEM).The effects of calcination temperature,category of sacrificial reagent,initial sacrificial reagent concentration,and Ag loading content on the photocatalytic activity of the as-obtained CuO sample were investigated.The results show that the as-obtained CuO exhibits high activity for photocatalysis of H2 evolution reaction(HER) in oxalic acid solution under simulated sunlight irradiation.The highest photocatalytic activity of the as-obtained CuO was achieved at the calcination temperature of 1000℃,and oxalic acid was used as the sacrificial reagent with the concentration 0.05 mol/L.H2 evolution rate is as high as 2.98 mmol/(h·g) with 2%(mass fraction) loaded Ag.The possible photocatalytic reaction mechanism on the CuO photocatalyst for HER in oxalic acid solution was also discussed.展开更多
A large number of experimental and theoretical investigations of carbon dioxide (CO 2 ) spectra have been conducted since the most recent update of the High-Resolution Transmission Molecular Absorption (HITRAN) da...A large number of experimental and theoretical investigations of carbon dioxide (CO 2 ) spectra have been conducted since the most recent update of the High-Resolution Transmission Molecular Absorption (HITRAN) database. To maintain optimal parameters, the HITRAN 2004 CO 2 line list has been completely replaced by HITRAN 2008 data in the near-infrared region from 4300 cm-1 to 7000 cm-1 . To examine the effect of this change on the retrieval of CO 2 vertical column data from reflected sunlight spectra in the 1.61-μm spectral window, synthetic measurements for a given atmospheric state and instrument setup were generated and compared using radiative transfer model with the line-transition parameters from the HITRAN 2004 and 2008 databases. Simulated retrievals were then performed based on the optimal estimation retrieval theory. The results show that large systematic errors in atmospheric CO 2 column retrievals were induced by the differences in the HITRAN laboratory line parameters in the 1.61-μm region. The retrieved CO 2 columns were underestimated by 10 ppm using the HITRAN 2004 data, and improvements resulting from the use of the improved HITRAN database were more pronounced at a higher spectral resolution.展开更多
A novel and effective BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst was synthesized through a precipitation method. The structure, morphology, and optical properties of the samples were certified by X-ray diffraction, UV...A novel and effective BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst was synthesized through a precipitation method. The structure, morphology, and optical properties of the samples were certified by X-ray diffraction, UV-Vis diffuse reflectance, scanning electron microscopy, and X-ray photoelectron spectroscopic characterizations. Photocatalytic experiments demonstrated that the synthesized BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst exhibited excellent photocatalytic performance toward the degradation of tetracycline hydrochloride(TCH) under simulated sunlight. Furthermore, the TCH degradation rate of BiOCl0.9I0.1/15%β-Bi2O3 increased by 27.6% and 61.4% compared with those of the pure BiOCl0.9I0.1 and pure β-Bi2O3, respectively. Due to the multiple vacancies and valence states possessed by BiOCl0.9I0.1/x%β-Bi2O3, namely Bi5+, Bi(3-x)+, Bi5+–O, Bi3+–O, I- and I3-, the charge separation in photocatalysis reactions can be effectively promoted. The Mott-Schottky measurements indicate that the conduction band(CB) level of BiOCl0.9I0.1/15%β-Bi2O3 becomes more negative relative to that of BiOCl0.9I0.1, guaranteeing an advantageous effect on the redox ability of the photocatalyst. This study provides a new bright spot for the construction of high-performance photocatalysts.展开更多
Zirconia-supported CuO (CuO/ZrO2) composite photocatalysts were successfully synthesized via citric acid-assisted sol-gel technique. For comparison, CuO/ZrO2 materials were also prepared by solid state reaction and ...Zirconia-supported CuO (CuO/ZrO2) composite photocatalysts were successfully synthesized via citric acid-assisted sol-gel technique. For comparison, CuO/ZrO2 materials were also prepared by solid state reaction and co-precipitation method. The as-prepared powders were characterized by X-ray diffractometry (XRD), transmission electron microscopy (TEM), and thermogravimetric-differential thermal analysis (TG-DTA). The photocatalytic activity of CuO/ZrO2 catalyst was investigated based on the H2 evolution from oxalic acid solution under simulated sunlight irradiation. The effects of molar ratio of CuO to ZrO2, preparation method, phase change with the calcination temperature and the durability on the photocatalytic activity of the photocatalyst were investigated in detail. It is found that the optimal activity of photocatalytic H2 evolution (2.41 mmol.h i.g-~) can be obtained when CuO/ZrO2 composite photocatalyst is synthesized by sol-gel technique and the mole ratio of CuO to ZrO2 is 40%. The activity of copper oxide supported on monoclinic ZrO2 calcined at higher temperature is much higher than that on tetragonal ZrO2 calcined at lower temperature, and the best calcination temperature is 900 ℃.展开更多
Theanine is a non-protein amino acid representing as much as 50% of the total amino acids in black tea and 1% - 2% of dry weight in green tea. It has been shown to be able to reduce high blood pressure, promote relaxa...Theanine is a non-protein amino acid representing as much as 50% of the total amino acids in black tea and 1% - 2% of dry weight in green tea. It has been shown to be able to reduce high blood pressure, promote relaxation, and inhibit caffeine’s side effects among others. This current study explored the effects of sunlight and withering durations on theanine levels in tea shoots. Theanine content from three leaves and a bud, two leaves and a bud and internodes were detected and quantified by using High Performance Liquid chromatography (HPLC). Sunlight exposure experiment was started at dawn (0600 HRS, GMT + 3.00) when the light intensity was low and tea was collected at three-hour interval throughout the day to (1800 Hrs, GMT + 3.00) when the light intensity had dropped. At the start of the experiment, the theanine levels were significantly high but as the intensity of sunlight increased during the day there was a significant drop in theanine levels, and as the sun set the theanine levels increased significantly again in all samples. The results also showed that theanine levels were significantly increased after 15 hours of withering. Three leaves and a bud withered for 3 hours had mean theanine levels of 1.41% and those withered for 15 hours had mean theanine levels of 3.11%. Internodes exhibited higher mean theanine levels than those of leaves. In the light of these results, it’s evident that withering for a longer period of time and harvesting of tea when the light intensity is low ensure high amount of theanine in tea.展开更多
We conducted ship-board incubation experiments to investigate changes in nutrient uptake of phytoplankton under different phosphate concentrations and irradiances in the Changjiang River Estuary and its adjacent water...We conducted ship-board incubation experiments to investigate changes in nutrient uptake of phytoplankton under different phosphate concentrations and irradiances in the Changjiang River Estuary and its adjacent waters in China. Under 100% natural irradiance the uptake rates of phosphate, silicate, and nitrate were accelerated at high phosphate levels (1.84 μM), while under low irradiance (about 50% natural irradiance) their uptake rates were restrained at the high but stimulated greatly at the intermediate phosphate concentrations (1.26 μM), as the growth of phytoplankton, changes in nitrite and ammonium uptake didn't follow an obvious pattern. Our results also showed that there were linear relationships between nitrate, silicate and phosphate uptake at different phosphate concentrations under low and high irradiances, and the growth period of phytoplankton was prolonged both at the high phosphate concentrations under high irradiance and at the intermediate concentrations under low irradiance, suggesting that the limitation of phytoplankton growth mainly reflected changes in its growth period, and because no such environment (low irradiance and low phosphate concentrations) actually existed in a high turbidity zone, phytoplankton blooms hardly occurred there. In the absence of irradiance, denitrification occurred readily and phytoplankton was kept decreasing, which resulted in phosphate regeneration.展开更多
On the basis of referring plenty of literatures, we summed up the research advance in effects of sun light on the internal quality of peach fruit. This paper discussed the effect of light on the internal quality of pe...On the basis of referring plenty of literatures, we summed up the research advance in effects of sun light on the internal quality of peach fruit. This paper discussed the effect of light on the internal quality of peach fruit under the conditions of open cultivation, protected cultivation, bagging and surface covering with reflective film, the mechanism of occurrence and the technical measures to improve the utilization rate of light and light energy, and prospected the future research work.展开更多
People living near the equator more easily obtain adequate 25-hydroxyvitamin D [25(OH)D]. However, studies indicated that vitamin D deficiency is common even in the sunniest areas. We mainly analyzed the vitamin D sta...People living near the equator more easily obtain adequate 25-hydroxyvitamin D [25(OH)D]. However, studies indicated that vitamin D deficiency is common even in the sunniest areas. We mainly analyzed the vitamin D status and dietary patterns of men highly exposed to sunlight, and investigated the correlation of vitamin D status with dietary patterns and time for outdoor work or activities. The average vitamin D levels among men highly exposed to sunlight was sufficient, but parts of the population had vitamin D deficiency or insufficiency. Long-term vitamin D deficiency may correlate with obesity and hypertension. These results provide a scientific basis for future research.展开更多
Objective This paper aims to evaluate the genotoxicity in peripheral blood lymphocytes of rats after exposure to sunlight at different time points of day in a tropical region of Brazil(5oS,42oW).Materials and Method...Objective This paper aims to evaluate the genotoxicity in peripheral blood lymphocytes of rats after exposure to sunlight at different time points of day in a tropical region of Brazil(5oS,42oW).Materials and Methods Thirty Wistar-Hannover rats,three months old,were randomly divided into three groups of 10 animals each:Group I [control,without exposure to ultraviolet(UV) radiation],Group II(exposed to sunlight during 08:00 a.m.to 10:00 a.m.),and Group III(exposed to sunlight during 10:00 a.m.to 12:00 a.m.).After a week of exposure,peripheral blood samples were taken from the tail of these animals to prepare smears on two slides per animal.In 24 h after exposure to sunlight in Group III,a new collection was obtained to observe the repair activity.The alkaline comet assay was used in this study to evaluate the genotoxic activity of sunlight(P0.05).Results There was no statistical difference between Group I and II(P=0.672).On the other hand,the exposure to sunlight in Group III showed genotoxic action in comparison to the other groups(P0.0001).Also,there was no significant repair in Group III R(P=0.407).Conclusion This study has shown a genotoxic potential of sunlight(UVA-B) in lymphocytes of mammals from 10:00 a.m.to 12:00 a.m.,due to a higher intensity of UV in this tropical region.展开更多
Two kinetic models were established for conservative estimates of photodegradation rates of contaminants under sunlight irradiation,in particular for wastewater stabilisation ponds and clarifiers in conventional waste...Two kinetic models were established for conservative estimates of photodegradation rates of contaminants under sunlight irradiation,in particular for wastewater stabilisation ponds and clarifiers in conventional wastewater treatment plants.These two models were designated for(1)contaminants with high photolytic rates or high photolytic quantum yields,whose photodegradation is unlikely to be enhanced by aquatic photosensitisers;and(2)contaminants withstanding direct photolysis in sunlit waters but subjected to indirect photolysis.The effortlessly intelligible prediction procedure involves sampling and analysis of real water samples,simulated solar experiments in the laboratory,and transfer of the laboratory results to realise water treatment using the prediction models.Although similar models have been widely used for laboratory studies,this paper provides a preliminary example of translating laboratory results to the photochemical fate of contaminants in real waters.展开更多
Black silicon, produced by irradiating the surface of a silicon wafer with femtosecond laser pulses in the presence of a sulfur-bearing gas, is widely believed to be a potential material for efficient multi-intermedia...Black silicon, produced by irradiating the surface of a silicon wafer with femtosecond laser pulses in the presence of a sulfur-bearing gas, is widely believed to be a potential material for efficient multi-intermediate-band silicon solar cells. Taking chalcogen as an example, we analyse the loss of sunlight for silicon with two impurity bands and we find that loss of the sunlight can be minimized to 0.332 when Te^0(0.307 eV) and Te+(0.411 eV) are doped into microstructured silicon. Finally, problems needed to be resolved in analysing the relationship between conversion efficiency of the ideal four-band silicon solar cell and the position of the introduced two intermediated bands in silicon according to detailed balance theory are pointed out with great emphasis.展开更多
PV modules are used as stand alone power sources for agricultural equipments such as lifting pumps in farms, where the power infrastructure is not yet improved. In order to expand the agricultural use of PV module, th...PV modules are used as stand alone power sources for agricultural equipments such as lifting pumps in farms, where the power infrastructure is not yet improved. In order to expand the agricultural use of PV module, the cost of PV generation should be reduced. In this paper, the power output performance of a commercial PV module was improved by using a sunlight concentrator that could be assembled inexpensively and a simple sun-tracking method.展开更多
In order to explore the law of photosynthetic active radiation in winter sunlight greenhouse in Panjin and serve the local facility agriculture better,based on the observed data of sunlight greenhouse microclimate and...In order to explore the law of photosynthetic active radiation in winter sunlight greenhouse in Panjin and serve the local facility agriculture better,based on the observed data of sunlight greenhouse microclimate and of the nearby weather station during winter in 2012,the methods of correlation analysis and stepwise regression analysis were adopted to study characteristics of photosynthetic active radiation in sunlight greenhouse and the ratio of photosynthetic active radiation to global radiation under different weather types during winter,and to set up forecast models of photosynthetic active radiation in sunlight greenhouse under different weather types during winter.The results showed that:(1) the daily variation of photosynthetic active radiation in sunlight greenhouse on sunny and cloudy days were both obvious,and photosynthetic active radiation in sunlight greenhouse was 1-38 W/m^2 when it's cloudy.(2) ηPARon typical cloudy day was the highest,on cloudy day was secondary and on sunny day was the minimum during winter;(3) the methods of stepwise regression analysis were respectively adopted to set up models of the highest daily maximum photosynthetic active radiation,the total daily photosynthetic active radiation,daily maximum global radiation,and the total daily global radiation in sunlight greenhouse associated with climate outside,the models passed the 0.01 level of significance,and fitting test had been carried out:4 factors were fitted well on sunny and cloudy day,but fitted poor on overcast day.展开更多
The relationships of nitrous oxide(N2O)and methane(CH4)emissions to other environmental parameters have been studied extensively in Antarctic terrestrial ecosystems.However,the effects of sunlight on soil N2O and CH4 ...The relationships of nitrous oxide(N2O)and methane(CH4)emissions to other environmental parameters have been studied extensively in Antarctic terrestrial ecosystems.However,the effects of sunlight on soil N2O and CH4 fluxes are neglected across the Antarctic tundra.Here,fluxes of N2O and CH4 from maritime Antarctic tundra soils were measured in the absence and presence of sunlight during three summers.The N2O fluxes averaged-4.6±1.2μg·m^-2·h^-1 in the absence of sunlight and 5.7±1.5μg·m^-2·h^-1 in its presence;CH4 fluxes averaged 119.8±24.5μg·m^-2·h^-1(absence)and-40.5±28.3μg·m^-2·h^-1(presence).The correlations between N2O and CH4 fluxes and other environmental variables(e.g.,soil moisture,temperature,organic and inorganic material)were not statistically significant(P>0.05)at all sites.On average,sunlight significantly increased N2O emissions and CH4 uptake by 10.3μg·m^-2·h^-1 and 160.3μg·m^-2·h^-1,respectively.This study indicates that sunlight is critical for accurately estimating N2O and CH4 budgets from maritime Antarctica and necessary for constraining the role of their emissions from tundra soil.展开更多
In order to explore the photocatalytic activity of the lanthanum and iodine co-doped TiO2,the degradation of acid blue 62 as a probe reaction under simulated sunlight irradiattion was investigated.A novel visible-ligh...In order to explore the photocatalytic activity of the lanthanum and iodine co-doped TiO2,the degradation of acid blue 62 as a probe reaction under simulated sunlight irradiattion was investigated.A novel visible-light-activated La/I/TiO2 nanocomposition photocatalyst was prepared using precipitation-diping method,and characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM)and UV-Vis diffuse reflectance spectroscopy(UV-Vis-DRS).The photocatalytic efficiency of La/I/TiO2 was evaluated by the photodegradation of reactive acid blue 62 as a probe reaction under simulated sunlight irradiationt.Photocatalytic experiment results shows that the La/I co-doped TiO2 catalyst has higher photocatalytic activity than the standard Degussa P25,La-doped TiO2 and I-doped TiO2 photocatalysts under simulated sunlight irradiation,and the way of La/I co-doping extends the absorption spectra of TiO2 and shifts the absorption edge remarkably toward longer wavelength.展开更多
The lethal effect produced by sunlight in bacteria depends on the photodynamic action of the ultraviolet component of the radiation. Neither the reactive oxygen species involved nor the targets for damage have been ce...The lethal effect produced by sunlight in bacteria depends on the photodynamic action of the ultraviolet component of the radiation. Neither the reactive oxygen species involved nor the targets for damage have been certainly identified, and the aim of this study was to address these issues. During exposures to natural sunlight, photo-protection provided by nitrogen sparging was compared with which provided by the addition of L-histidine (an efficient scavenger for hydroxyl radical and singlet oxygen) or mannitol (an hydroxyl radical scavenger which reacts poorly with singlet oxygen) to the irradiation medium. Both scavengers reproduced for the most part the effect of oxygen depletion, indicating that damage depends mainly on hydroxyl radical generation. Survival of irradiated bacteria decreased considerably when they were cultured using a substrate unsuitable for fermentation, suggesting that respiration impairment is a key factor in cell killing. This observation is in keeping with the notion that the respiratory chain is the main target for the action of sunlight in Escherichia coli.展开更多
Energy-saving solar greenhouse vegetables cultivating is to create and improve microclimate environment with greenhouse in those seasons impossible for open cultivation production and in order to achieve the purpose o...Energy-saving solar greenhouse vegetables cultivating is to create and improve microclimate environment with greenhouse in those seasons impossible for open cultivation production and in order to achieve the purpose of harvest in advance or in delay. Since a greenhouse needs huge construction expenses and high production costs, only though the improvement of facility utilization can we obtain better economic benefits. Vegetable germination and seedling stage need a long time for ground, so they need smaller standing area. So we concentrated in a small area of cultivation can not only create a suitable environment easily, nurture strong age seedling, but also can avoid greenhouse waste. Make transplanting to greenhouse after Seedlings breeding can effectively reduce the fertility cycle and substantially increase greenhouse utilization.展开更多
基金Project supported by the National Natural Science Foundation of China(No. 20677008)the Innovation Foundation of Donghua University for Doctors(No. 113-06-001900621).
文摘The novel CuO-SnO2 nanocomposite oxide photocatalysts were prepared by simple co-precipitation method, and characterized by X- ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurement and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activities of CuO-SnO2, evaluated using the photodegradation of Acid Blue 62 as a probe reaction under the irradiation of Xenon light, were also found to be related to the calcination temperature and the molar ratio of Cu to Sn. The maximum photocatalytic activity of the CuO-SnO2 photocatalyst was observed to be calcined at 500~C for 3 h (the molar ratio of Cu to Sn was 1:1) due to the sample with good crystallization and high surface area. It also showed much higher photocatalytic activity in treatment dye wastewater under simulated sunlight irradiation compared to Degussa P25 TiO2.
基金Project(20876039) supported by the National Natural Science Foundation of ChinaProject(09JJ3023) supported by Natural Science Foundation of Hunan Province, China
文摘CuO was synthesized by thermal decomposition of Cu(NO3)2·3H2O at various temperatures and characterized by powder X-ray diffractometry(XRD) as well as scanning electron microscopy(SEM).The effects of calcination temperature,category of sacrificial reagent,initial sacrificial reagent concentration,and Ag loading content on the photocatalytic activity of the as-obtained CuO sample were investigated.The results show that the as-obtained CuO exhibits high activity for photocatalysis of H2 evolution reaction(HER) in oxalic acid solution under simulated sunlight irradiation.The highest photocatalytic activity of the as-obtained CuO was achieved at the calcination temperature of 1000℃,and oxalic acid was used as the sacrificial reagent with the concentration 0.05 mol/L.H2 evolution rate is as high as 2.98 mmol/(h·g) with 2%(mass fraction) loaded Ag.The possible photocatalytic reaction mechanism on the CuO photocatalyst for HER in oxalic acid solution was also discussed.
基金supported by the National Natural Science Foundation of China (Grant No 41130104)Ministry of Science and Technology of China (Grant No 2010DFA22770)+1 种基金the key projects fromthe 11th Five-Year Plan of national scientific and technological (Grant No 2008BAC34B04-2)the National Basic Research Program of China (also called 973 Program,Grant Nos 2005CB422200x and 2006CB403702)
文摘A large number of experimental and theoretical investigations of carbon dioxide (CO 2 ) spectra have been conducted since the most recent update of the High-Resolution Transmission Molecular Absorption (HITRAN) database. To maintain optimal parameters, the HITRAN 2004 CO 2 line list has been completely replaced by HITRAN 2008 data in the near-infrared region from 4300 cm-1 to 7000 cm-1 . To examine the effect of this change on the retrieval of CO 2 vertical column data from reflected sunlight spectra in the 1.61-μm spectral window, synthetic measurements for a given atmospheric state and instrument setup were generated and compared using radiative transfer model with the line-transition parameters from the HITRAN 2004 and 2008 databases. Simulated retrievals were then performed based on the optimal estimation retrieval theory. The results show that large systematic errors in atmospheric CO 2 column retrievals were induced by the differences in the HITRAN laboratory line parameters in the 1.61-μm region. The retrieved CO 2 columns were underestimated by 10 ppm using the HITRAN 2004 data, and improvements resulting from the use of the improved HITRAN database were more pronounced at a higher spectral resolution.
文摘A novel and effective BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst was synthesized through a precipitation method. The structure, morphology, and optical properties of the samples were certified by X-ray diffraction, UV-Vis diffuse reflectance, scanning electron microscopy, and X-ray photoelectron spectroscopic characterizations. Photocatalytic experiments demonstrated that the synthesized BiOCl0.9I0.1/x%β-Bi2O3 composite catalyst exhibited excellent photocatalytic performance toward the degradation of tetracycline hydrochloride(TCH) under simulated sunlight. Furthermore, the TCH degradation rate of BiOCl0.9I0.1/15%β-Bi2O3 increased by 27.6% and 61.4% compared with those of the pure BiOCl0.9I0.1 and pure β-Bi2O3, respectively. Due to the multiple vacancies and valence states possessed by BiOCl0.9I0.1/x%β-Bi2O3, namely Bi5+, Bi(3-x)+, Bi5+–O, Bi3+–O, I- and I3-, the charge separation in photocatalysis reactions can be effectively promoted. The Mott-Schottky measurements indicate that the conduction band(CB) level of BiOCl0.9I0.1/15%β-Bi2O3 becomes more negative relative to that of BiOCl0.9I0.1, guaranteeing an advantageous effect on the redox ability of the photocatalyst. This study provides a new bright spot for the construction of high-performance photocatalysts.
基金Project(20876039) supported by the National Natural Science Foundation of ChinaProject(09JJ3023) supported by the Natural Science Foundation of Hunan Province,China
文摘Zirconia-supported CuO (CuO/ZrO2) composite photocatalysts were successfully synthesized via citric acid-assisted sol-gel technique. For comparison, CuO/ZrO2 materials were also prepared by solid state reaction and co-precipitation method. The as-prepared powders were characterized by X-ray diffractometry (XRD), transmission electron microscopy (TEM), and thermogravimetric-differential thermal analysis (TG-DTA). The photocatalytic activity of CuO/ZrO2 catalyst was investigated based on the H2 evolution from oxalic acid solution under simulated sunlight irradiation. The effects of molar ratio of CuO to ZrO2, preparation method, phase change with the calcination temperature and the durability on the photocatalytic activity of the photocatalyst were investigated in detail. It is found that the optimal activity of photocatalytic H2 evolution (2.41 mmol.h i.g-~) can be obtained when CuO/ZrO2 composite photocatalyst is synthesized by sol-gel technique and the mole ratio of CuO to ZrO2 is 40%. The activity of copper oxide supported on monoclinic ZrO2 calcined at higher temperature is much higher than that on tetragonal ZrO2 calcined at lower temperature, and the best calcination temperature is 900 ℃.
文摘Theanine is a non-protein amino acid representing as much as 50% of the total amino acids in black tea and 1% - 2% of dry weight in green tea. It has been shown to be able to reduce high blood pressure, promote relaxation, and inhibit caffeine’s side effects among others. This current study explored the effects of sunlight and withering durations on theanine levels in tea shoots. Theanine content from three leaves and a bud, two leaves and a bud and internodes were detected and quantified by using High Performance Liquid chromatography (HPLC). Sunlight exposure experiment was started at dawn (0600 HRS, GMT + 3.00) when the light intensity was low and tea was collected at three-hour interval throughout the day to (1800 Hrs, GMT + 3.00) when the light intensity had dropped. At the start of the experiment, the theanine levels were significantly high but as the intensity of sunlight increased during the day there was a significant drop in theanine levels, and as the sun set the theanine levels increased significantly again in all samples. The results also showed that theanine levels were significantly increased after 15 hours of withering. Three leaves and a bud withered for 3 hours had mean theanine levels of 1.41% and those withered for 15 hours had mean theanine levels of 3.11%. Internodes exhibited higher mean theanine levels than those of leaves. In the light of these results, it’s evident that withering for a longer period of time and harvesting of tea when the light intensity is low ensure high amount of theanine in tea.
文摘We conducted ship-board incubation experiments to investigate changes in nutrient uptake of phytoplankton under different phosphate concentrations and irradiances in the Changjiang River Estuary and its adjacent waters in China. Under 100% natural irradiance the uptake rates of phosphate, silicate, and nitrate were accelerated at high phosphate levels (1.84 μM), while under low irradiance (about 50% natural irradiance) their uptake rates were restrained at the high but stimulated greatly at the intermediate phosphate concentrations (1.26 μM), as the growth of phytoplankton, changes in nitrite and ammonium uptake didn't follow an obvious pattern. Our results also showed that there were linear relationships between nitrate, silicate and phosphate uptake at different phosphate concentrations under low and high irradiances, and the growth period of phytoplankton was prolonged both at the high phosphate concentrations under high irradiance and at the intermediate concentrations under low irradiance, suggesting that the limitation of phytoplankton growth mainly reflected changes in its growth period, and because no such environment (low irradiance and low phosphate concentrations) actually existed in a high turbidity zone, phytoplankton blooms hardly occurred there. In the absence of irradiance, denitrification occurred readily and phytoplankton was kept decreasing, which resulted in phosphate regeneration.
基金Supported by Innovative Engineering Project of Hebei Academy of Agriculture and Forestry Sciences(2018100201,2019-3-5-1,2019-1-1-6)Hebei Science and Technology Support Program(16226313D-3)Shijiazhuang Comprehensive Experimental Station of National Peach Industry Technology System(CARS-31-Z-2)。
文摘On the basis of referring plenty of literatures, we summed up the research advance in effects of sun light on the internal quality of peach fruit. This paper discussed the effect of light on the internal quality of peach fruit under the conditions of open cultivation, protected cultivation, bagging and surface covering with reflective film, the mechanism of occurrence and the technical measures to improve the utilization rate of light and light energy, and prospected the future research work.
基金funded by a Special Scientific Research Fund of Public Welfare Profession of Ministry of Health of China(Grant No.201202012)a fund supported by the Science and Technology Ministry of China(Grant No.2012BAI02B03)a grant from the National Natural Science Foundation of China(Grant No.81372992)
文摘People living near the equator more easily obtain adequate 25-hydroxyvitamin D [25(OH)D]. However, studies indicated that vitamin D deficiency is common even in the sunniest areas. We mainly analyzed the vitamin D status and dietary patterns of men highly exposed to sunlight, and investigated the correlation of vitamin D status with dietary patterns and time for outdoor work or activities. The average vitamin D levels among men highly exposed to sunlight was sufficient, but parts of the population had vitamin D deficiency or insufficiency. Long-term vitamin D deficiency may correlate with obesity and hypertension. These results provide a scientific basis for future research.
文摘Objective This paper aims to evaluate the genotoxicity in peripheral blood lymphocytes of rats after exposure to sunlight at different time points of day in a tropical region of Brazil(5oS,42oW).Materials and Methods Thirty Wistar-Hannover rats,three months old,were randomly divided into three groups of 10 animals each:Group I [control,without exposure to ultraviolet(UV) radiation],Group II(exposed to sunlight during 08:00 a.m.to 10:00 a.m.),and Group III(exposed to sunlight during 10:00 a.m.to 12:00 a.m.).After a week of exposure,peripheral blood samples were taken from the tail of these animals to prepare smears on two slides per animal.In 24 h after exposure to sunlight in Group III,a new collection was obtained to observe the repair activity.The alkaline comet assay was used in this study to evaluate the genotoxic activity of sunlight(P0.05).Results There was no statistical difference between Group I and II(P=0.672).On the other hand,the exposure to sunlight in Group III showed genotoxic action in comparison to the other groups(P0.0001).Also,there was no significant repair in Group III R(P=0.407).Conclusion This study has shown a genotoxic potential of sunlight(UVA-B) in lymphocytes of mammals from 10:00 a.m.to 12:00 a.m.,due to a higher intensity of UV in this tropical region.
文摘Two kinetic models were established for conservative estimates of photodegradation rates of contaminants under sunlight irradiation,in particular for wastewater stabilisation ponds and clarifiers in conventional wastewater treatment plants.These two models were designated for(1)contaminants with high photolytic rates or high photolytic quantum yields,whose photodegradation is unlikely to be enhanced by aquatic photosensitisers;and(2)contaminants withstanding direct photolysis in sunlit waters but subjected to indirect photolysis.The effortlessly intelligible prediction procedure involves sampling and analysis of real water samples,simulated solar experiments in the laboratory,and transfer of the laboratory results to realise water treatment using the prediction models.Although similar models have been widely used for laboratory studies,this paper provides a preliminary example of translating laboratory results to the photochemical fate of contaminants in real waters.
基金Project supported by the Key Program of Natural Science Foundation of Guangdong Province of China (Grant Nos.10251063101000001 and 8251063101000006)the National Natural Science Foundation of China (Grant No.60878063)
文摘Black silicon, produced by irradiating the surface of a silicon wafer with femtosecond laser pulses in the presence of a sulfur-bearing gas, is widely believed to be a potential material for efficient multi-intermediate-band silicon solar cells. Taking chalcogen as an example, we analyse the loss of sunlight for silicon with two impurity bands and we find that loss of the sunlight can be minimized to 0.332 when Te^0(0.307 eV) and Te+(0.411 eV) are doped into microstructured silicon. Finally, problems needed to be resolved in analysing the relationship between conversion efficiency of the ideal four-band silicon solar cell and the position of the introduced two intermediated bands in silicon according to detailed balance theory are pointed out with great emphasis.
基金Supported by Curriculum for Practical Overseas Education in La Paz, Mexico
文摘PV modules are used as stand alone power sources for agricultural equipments such as lifting pumps in farms, where the power infrastructure is not yet improved. In order to expand the agricultural use of PV module, the cost of PV generation should be reduced. In this paper, the power output performance of a commercial PV module was improved by using a sunlight concentrator that could be assembled inexpensively and a simple sun-tracking method.
基金Supported by Special Program for Scientific Research in Public Service Industry"Studies on Professional Weather Report for Agricultural Production in Northeast China"(GYHY201206024)~~
文摘In order to explore the law of photosynthetic active radiation in winter sunlight greenhouse in Panjin and serve the local facility agriculture better,based on the observed data of sunlight greenhouse microclimate and of the nearby weather station during winter in 2012,the methods of correlation analysis and stepwise regression analysis were adopted to study characteristics of photosynthetic active radiation in sunlight greenhouse and the ratio of photosynthetic active radiation to global radiation under different weather types during winter,and to set up forecast models of photosynthetic active radiation in sunlight greenhouse under different weather types during winter.The results showed that:(1) the daily variation of photosynthetic active radiation in sunlight greenhouse on sunny and cloudy days were both obvious,and photosynthetic active radiation in sunlight greenhouse was 1-38 W/m^2 when it's cloudy.(2) ηPARon typical cloudy day was the highest,on cloudy day was secondary and on sunny day was the minimum during winter;(3) the methods of stepwise regression analysis were respectively adopted to set up models of the highest daily maximum photosynthetic active radiation,the total daily photosynthetic active radiation,daily maximum global radiation,and the total daily global radiation in sunlight greenhouse associated with climate outside,the models passed the 0.01 level of significance,and fitting test had been carried out:4 factors were fitted well on sunny and cloudy day,but fitted poor on overcast day.
基金supported by the National Natural Science Foundation of China(Grant nos.41776190,41976220)。
文摘The relationships of nitrous oxide(N2O)and methane(CH4)emissions to other environmental parameters have been studied extensively in Antarctic terrestrial ecosystems.However,the effects of sunlight on soil N2O and CH4 fluxes are neglected across the Antarctic tundra.Here,fluxes of N2O and CH4 from maritime Antarctic tundra soils were measured in the absence and presence of sunlight during three summers.The N2O fluxes averaged-4.6±1.2μg·m^-2·h^-1 in the absence of sunlight and 5.7±1.5μg·m^-2·h^-1 in its presence;CH4 fluxes averaged 119.8±24.5μg·m^-2·h^-1(absence)and-40.5±28.3μg·m^-2·h^-1(presence).The correlations between N2O and CH4 fluxes and other environmental variables(e.g.,soil moisture,temperature,organic and inorganic material)were not statistically significant(P>0.05)at all sites.On average,sunlight significantly increased N2O emissions and CH4 uptake by 10.3μg·m^-2·h^-1 and 160.3μg·m^-2·h^-1,respectively.This study indicates that sunlight is critical for accurately estimating N2O and CH4 budgets from maritime Antarctica and necessary for constraining the role of their emissions from tundra soil.
基金Foundation items: The Key Scientific and Technological Project of Shanghai, China (No. 09231202805) Shanghai Leading Academic Discipline Project, China (No. B604)
文摘In order to explore the photocatalytic activity of the lanthanum and iodine co-doped TiO2,the degradation of acid blue 62 as a probe reaction under simulated sunlight irradiattion was investigated.A novel visible-light-activated La/I/TiO2 nanocomposition photocatalyst was prepared using precipitation-diping method,and characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM)and UV-Vis diffuse reflectance spectroscopy(UV-Vis-DRS).The photocatalytic efficiency of La/I/TiO2 was evaluated by the photodegradation of reactive acid blue 62 as a probe reaction under simulated sunlight irradiationt.Photocatalytic experiment results shows that the La/I co-doped TiO2 catalyst has higher photocatalytic activity than the standard Degussa P25,La-doped TiO2 and I-doped TiO2 photocatalysts under simulated sunlight irradiation,and the way of La/I co-doping extends the absorption spectra of TiO2 and shifts the absorption edge remarkably toward longer wavelength.
文摘The lethal effect produced by sunlight in bacteria depends on the photodynamic action of the ultraviolet component of the radiation. Neither the reactive oxygen species involved nor the targets for damage have been certainly identified, and the aim of this study was to address these issues. During exposures to natural sunlight, photo-protection provided by nitrogen sparging was compared with which provided by the addition of L-histidine (an efficient scavenger for hydroxyl radical and singlet oxygen) or mannitol (an hydroxyl radical scavenger which reacts poorly with singlet oxygen) to the irradiation medium. Both scavengers reproduced for the most part the effect of oxygen depletion, indicating that damage depends mainly on hydroxyl radical generation. Survival of irradiated bacteria decreased considerably when they were cultured using a substrate unsuitable for fermentation, suggesting that respiration impairment is a key factor in cell killing. This observation is in keeping with the notion that the respiratory chain is the main target for the action of sunlight in Escherichia coli.
文摘Energy-saving solar greenhouse vegetables cultivating is to create and improve microclimate environment with greenhouse in those seasons impossible for open cultivation production and in order to achieve the purpose of harvest in advance or in delay. Since a greenhouse needs huge construction expenses and high production costs, only though the improvement of facility utilization can we obtain better economic benefits. Vegetable germination and seedling stage need a long time for ground, so they need smaller standing area. So we concentrated in a small area of cultivation can not only create a suitable environment easily, nurture strong age seedling, but also can avoid greenhouse waste. Make transplanting to greenhouse after Seedlings breeding can effectively reduce the fertility cycle and substantially increase greenhouse utilization.