This research documents and visualizes the intricate relationships among sunlight,built form,and public life specifically within Toronto’s core.Utilizing photographs and stop-motion videos,the study captured the dyna...This research documents and visualizes the intricate relationships among sunlight,built form,and public life specifically within Toronto’s core.Utilizing photographs and stop-motion videos,the study captured the dynamic movement of sunlight and observed corresponding differences in human behavior under varying light conditions.Maps and diagrams,generated using Rhino3D/Ladybug software,were employed to visualize the annual sunlight conditions throughout the defined study area.Building upon existing scholarship,this research affirms a strong relationship between sunlight and public life,noting that this relationship shifts with the changing seasons.The study concludes with a series of recommendations focused on the protection,expansion,and intensification of public space exposed to winter sunlight,particularly along pedestrian-oriented shopping streets,and advocates for the strategic use of large deciduous trees to manage sunlight across different seasons.The rapid transformation of downtown Toronto’s built form necessitates swift action to address these issues.While the research and its recommendations are centered on Toronto,they are potentially applicable to other cities that share similar climates,sunlight conditions,and built environments.展开更多
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
In this work Gd/La@ZnO nanoflower photocatalyst was successfully synthesized by a co-precipitation method and applied for rhodamine B(Rh B)and tetracycline(TCN)degradation under direct sunlight irradiation.The doping ...In this work Gd/La@ZnO nanoflower photocatalyst was successfully synthesized by a co-precipitation method and applied for rhodamine B(Rh B)and tetracycline(TCN)degradation under direct sunlight irradiation.The doping of rare earth elements extends the optical absorption wavelength of ZnO from UV region(390 nm)to visible-light region(401 nm).In addition,the co-doped ZnO nanoflower exhibits a lower charge recombination efficiency which was confirmed by photoluminescence emission analysis.Moreover,the co-doped ZnO nanoflower exhibits the maximum degradation efficiency of 91%for Rh B and 74%for TCN under sunlight irradiation.The calculated synergistic index of co-doped ZnO is higher than that of the pure ZnO.Reactive radicals’production was confirmed by terephthalic acid(TA)and nitro-blue tetrazolium(NBT)tests.The holes and hydroxyl(·OH)radicals play the major role in degradation reaction and it was confirmed by scavenger’s test.Moreover,the recycling test confirms the stability of the photocatalyst.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 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
Sunlight-driven C-TiO2/FeTiO3 composites were synthesized with different weight fractions of FeTiO3. The as-prepared samples were characterized by UV-Visible diffuse reflectance spectroscopy, Fourier transform infrare...Sunlight-driven C-TiO2/FeTiO3 composites were synthesized with different weight fractions of FeTiO3. The as-prepared samples were characterized by UV-Visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, energy-dis- persive X-ray spectroscopy, and photoluminescence. Under sunlight irradiation, the C-TiO2/FeTiO3 photocatalysts degraded methyl orange （MO） efficiently and displayed much higher photocatalytic activity than that of pure FeTiO3 or carbon-doped titanium dioxide （C-TiO2）, and the C-TiOE/FeTiO3 photocatalyst with 10 wt% of FeTiO3 exhibited the highest photocatalytic activity. The enhancement of photocatalytic activity was mainly ascribed to the formation of a heterojunction between C-TiO2 and FeTiO3, which facilitated the transfer and separation of photogenerated electron-hole pairs. The quenching effects of different scavengers demonstrated that the reactive superoxide radicals （02-） and hydroxyl radicals （OH） played a major role in the MO degradation. The possible photocatalytic mechanism is discussed on the basis of the band structures of C-TiO2 and FeTiO3. To further enhance the photocatalytic efficiency, double-heterojunctioned CQD/C-TiO2/FeTiO3 composite was prepared by loading carbon quantum dots onto the C-TiO2/FeTiO3 surface.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
Nanomaterials are considered as suitable heterogeneous catalysts for many organic reactions.Herein nano-tube TiO_(2) has been reported as a heterogeneous catalyst,for synthesis of imines in sunlight at room temperatur...Nanomaterials are considered as suitable heterogeneous catalysts for many organic reactions.Herein nano-tube TiO_(2) has been reported as a heterogeneous catalyst,for synthesis of imines in sunlight at room temperature under solvent-free conditions.The condensation of less electrophilic carbonyl compounds with poorly nucleophilic amines was afforded imines in excellent yields.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
The major findings in this report are(ⅰ)development of nanocomposite photocatalyst working through Z-scheme charge transfer pathway across the heterojunction,(ⅱ)utilization of direct sunlight as the photo-source,and...The major findings in this report are(ⅰ)development of nanocomposite photocatalyst working through Z-scheme charge transfer pathway across the heterojunction,(ⅱ)utilization of direct sunlight as the photo-source,and(ⅲ)prospect of ligand-hole in photocatalysis through enhanced sub-band gap absorption,The photocatalysts,namely LaNiO_(3),g-C_(3)N_(4) and LaNiO_(3)/g-C_(3)N_(4) nanocomposites were synthesized via facile route and were characterized for their structure,morphology,microstructure,texture,elemental mapping and surface oxidation states by using several physicochemical techniques.The photocatalytic performance of the nanocomposite was tested through the degradation of hazardous azo dye pollutants,namely reactive black 5 and methylene blue as well as the colorless antibiotic-pollutant tetracycline hydrochloride in aqueous solution in presence of natural sunlight with excellent recycling activity.The 10%LaNiO_(3)/g-C_(3)N_(4) nanocomposite sample shows the best catalytic activity,degrading respectively 94%,98.6%and 88.1%of reactive black 5,methylene blue and tetracycline hydrochloride in60,180 and 120 min.The photocatalytic activity of the nanocomposite phase is several times superior to that of the pure phases.The improvements of photocatalytic activity of g-C_(3)N_(4) in the nanocomposite have been rationalized through the construction of direct Z-scheme heterojunction and suppression of electron-hole pair recombination efficiency.The enhanced photo-absorption of the nanocomposite can possibly be related to sub-bandgap absorption,which is associated to the midgap state originating from ligand-hole formation or defects in the structure.The photodegradation process is mediated through the formation of super oxide radical(O_(2))and hole(h^(+))as the main responsible species.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
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
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
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
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
文摘This research documents and visualizes the intricate relationships among sunlight,built form,and public life specifically within Toronto’s core.Utilizing photographs and stop-motion videos,the study captured the dynamic movement of sunlight and observed corresponding differences in human behavior under varying light conditions.Maps and diagrams,generated using Rhino3D/Ladybug software,were employed to visualize the annual sunlight conditions throughout the defined study area.Building upon existing scholarship,this research affirms a strong relationship between sunlight and public life,noting that this relationship shifts with the changing seasons.The study concludes with a series of recommendations focused on the protection,expansion,and intensification of public space exposed to winter sunlight,particularly along pedestrian-oriented shopping streets,and advocates for the strategic use of large deciduous trees to manage sunlight across different seasons.The rapid transformation of downtown Toronto’s built form necessitates swift action to address these issues.While the research and its recommendations are centered on Toronto,they are potentially applicable to other cities that share similar climates,sunlight conditions,and built environments.
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Research Supporting Project(RefRSP-2021/160)King Saud University。
文摘In this work Gd/La@ZnO nanoflower photocatalyst was successfully synthesized by a co-precipitation method and applied for rhodamine B(Rh B)and tetracycline(TCN)degradation under direct sunlight irradiation.The doping of rare earth elements extends the optical absorption wavelength of ZnO from UV region(390 nm)to visible-light region(401 nm).In addition,the co-doped ZnO nanoflower exhibits a lower charge recombination efficiency which was confirmed by photoluminescence emission analysis.Moreover,the co-doped ZnO nanoflower exhibits the maximum degradation efficiency of 91%for Rh B and 74%for TCN under sunlight irradiation.The calculated synergistic index of co-doped ZnO is higher than that of the pure ZnO.Reactive radicals’production was confirmed by terephthalic acid(TA)and nitro-blue tetrazolium(NBT)tests.The holes and hydroxyl(·OH)radicals play the major role in degradation reaction and it was confirmed by scavenger’s test.Moreover,the recycling test confirms the stability of the photocatalyst.
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.
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the University Grants Commission(UGC), New Delhi,India,for financial support with Ref.No.:17-06/ 2012(i)EU-V
文摘Sunlight-driven C-TiO2/FeTiO3 composites were synthesized with different weight fractions of FeTiO3. The as-prepared samples were characterized by UV-Visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, energy-dis- persive X-ray spectroscopy, and photoluminescence. Under sunlight irradiation, the C-TiO2/FeTiO3 photocatalysts degraded methyl orange （MO） efficiently and displayed much higher photocatalytic activity than that of pure FeTiO3 or carbon-doped titanium dioxide （C-TiO2）, and the C-TiOE/FeTiO3 photocatalyst with 10 wt% of FeTiO3 exhibited the highest photocatalytic activity. The enhancement of photocatalytic activity was mainly ascribed to the formation of a heterojunction between C-TiO2 and FeTiO3, which facilitated the transfer and separation of photogenerated electron-hole pairs. The quenching effects of different scavengers demonstrated that the reactive superoxide radicals （02-） and hydroxyl radicals （OH） played a major role in the MO degradation. The possible photocatalytic mechanism is discussed on the basis of the band structures of C-TiO2 and FeTiO3. To further enhance the photocatalytic efficiency, double-heterojunctioned CQD/C-TiO2/FeTiO3 composite was prepared by loading carbon quantum dots onto the C-TiO2/FeTiO3 surface.
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the Iran National Science Foundation(No.87040564)for financial support
文摘Nanomaterials are considered as suitable heterogeneous catalysts for many organic reactions.Herein nano-tube TiO_(2) has been reported as a heterogeneous catalyst,for synthesis of imines in sunlight at room temperature under solvent-free conditions.The condensation of less electrophilic carbonyl compounds with poorly nucleophilic amines was afforded imines in excellent yields.
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 ℃.
基金Project supported by the Science and Engineering Research Board(SERB),Government of India(EMR/2016/001811,EMR/2016/000083)。
文摘The major findings in this report are(ⅰ)development of nanocomposite photocatalyst working through Z-scheme charge transfer pathway across the heterojunction,(ⅱ)utilization of direct sunlight as the photo-source,and(ⅲ)prospect of ligand-hole in photocatalysis through enhanced sub-band gap absorption,The photocatalysts,namely LaNiO_(3),g-C_(3)N_(4) and LaNiO_(3)/g-C_(3)N_(4) nanocomposites were synthesized via facile route and were characterized for their structure,morphology,microstructure,texture,elemental mapping and surface oxidation states by using several physicochemical techniques.The photocatalytic performance of the nanocomposite was tested through the degradation of hazardous azo dye pollutants,namely reactive black 5 and methylene blue as well as the colorless antibiotic-pollutant tetracycline hydrochloride in aqueous solution in presence of natural sunlight with excellent recycling activity.The 10%LaNiO_(3)/g-C_(3)N_(4) nanocomposite sample shows the best catalytic activity,degrading respectively 94%,98.6%and 88.1%of reactive black 5,methylene blue and tetracycline hydrochloride in60,180 and 120 min.The photocatalytic activity of the nanocomposite phase is several times superior to that of the pure phases.The improvements of photocatalytic activity of g-C_(3)N_(4) in the nanocomposite have been rationalized through the construction of direct Z-scheme heterojunction and suppression of electron-hole pair recombination efficiency.The enhanced photo-absorption of the nanocomposite can possibly be related to sub-bandgap absorption,which is associated to the midgap state originating from ligand-hole formation or defects in the structure.The photodegradation process is mediated through the formation of super oxide radical(O_(2))and hole(h^(+))as the main responsible species.
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.
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.
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.
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.
