This study assessed the feasibility of developing a machine vision system equipped with ultraviolet (UV) light, using changes in fish-surface color to predict aerobic plate count (APC, a standard freshness indicator) ...This study assessed the feasibility of developing a machine vision system equipped with ultraviolet (UV) light, using changes in fish-surface color to predict aerobic plate count (APC, a standard freshness indicator) during storage. The APC values were tested and images of the fish surface were taken when fish were stored at room temperature. Then, images</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">’</span></span></span><span><span><span><span> color-space conversion among RGB, HSV, and L*a*b* color spaces was carried out and analyzed. The results revealed that a* and b* values from the UV-light image decreased linearly during storage. A further regression analysis of these two parameters with APC value demonstrated a good exponential relationship between the a* value and the APC value (R</span><sup><span>2</span></sup><span> = 0.97), followed by the b* (R</span><sup><span>2</span></sup><span> = 0.85). Therefore, our results suggest that the change in color of the fish surface under UV light can be used to assess fish freshness during storage.展开更多
Understanding chemical transformations of contaminants and the resulting products is extremely important in devising proper monitoring methods for such contaminants and in assessing potential human exposure to the tra...Understanding chemical transformations of contaminants and the resulting products is extremely important in devising proper monitoring methods for such contaminants and in assessing potential human exposure to the transformation products in the environment. Ultraviolet (UV) light from the sun can induce various photochemical transformations of contaminants in the environment. Alkylnaphthalenes are light-molecular-weight polycyclic aromatic hydrocarbons (PAHs) which are one of the most widespread organic pollutants present in ambient air as a result of a variety of incomplete combustion sources. In this study, 1-methylnapthalene,a typical example of an alkylnaphthalene, was subjected to UV irradiation to investigate its transformation in the presence and absence of air. Twenty-one products were detected in the reaction mixtures. Some photo-oxidation products were identified, including both ring-opened and ring-retained oxygenated compounds, such as 1-naphthaldehyde, 1-naphthoic acid, 1-naphthalenemethanol and phthalic anhydride. Although dimeric products were observed in the presence of air, more were found in the presence of helium or argon gas, indicating a different photo-oxidation pathway from those commonly observed in other media, such as water. Under just 48 hours of exposure to the UV light in the presence of air, three major products were formed with a production yield of about 10% each. Compared to 1-methylnapthalene, the UV induced transformation products observed in this study are more volatile, acidic, water soluble or toxic. The formation of these products may significantly change our understanding of the risks assessed solely from the parent compound in contaminants research and supports the inclusion of airborne transformations of the parent compound in risk assessment.展开更多
Based on previous work, it has been hypothesized that the energetics of ultraviolet (UV) light disrupts effects induced by receptor-binding ligands. If this hypothesis is true, then UV light should (i) disrupt a broad...Based on previous work, it has been hypothesized that the energetics of ultraviolet (UV) light disrupts effects induced by receptor-binding ligands. If this hypothesis is true, then UV light should (i) disrupt a broad variety of endpoints and (ii) disrupt effects produced by ligands that bind to diverse receptor types. This was tested directly in the present study by using ligands selective for four different receptors (one ionotropic, three metabotropic) and three different behavioral endpoints. The selective dopamine D2 receptor antagonist (–)sulpiride (0.1 uM) dose-relatedly decreased spontaneous locomotor velocity, the selective nicotinic acetylcholine receptor agonist nicotine (1, 3, 5 mM) and the selective muscarinic acetylcholine receptor agonist pilocarpine (20, 30, 50 mM) induced seizure-like activity, and the selective-opioid receptor agonist U-50,488H (10 uM) produced physical dependence (manifested as abstinence-induced withdrawal) in planarian models. Each of these diverse ligand and receptor-mediated effects were attenuated by UV light (254 nm = 7.83 × 10–19 J = 4.89 eV). These findings provide further evidence that UV light disrupts ligand-receptor mediated interactions and that UV light might provide a useful tool for examining drug-receptor interactions.展开更多
After comparison of Trichoderma population density and test of colonization ability in rhizospheres were conducted. Auxotrophic mutants of T. harzianum tolerant to carbendazim and UV-light were obtained by UV-light mu...After comparison of Trichoderma population density and test of colonization ability in rhizospheres were conducted. Auxotrophic mutants of T. harzianum tolerant to carbendazim and UV-light were obtained by UV-light mutagenesis and carbendazim stress on PDA medium and a basis medium with hot pepper root exudation by adding the fungicide. The results showed: all four different isolates of Trichoderma had certain colonization ability in rhizosphere with the characteristic of growing as roots and distributing many more around root tips. The ability, however, was different for the 4 isolates, showing the wild isolates colonized weakly in rhizosphere. Around 5% spores alive and mutants could be obtained after the isolates were irradiated under a 20W UV-light at 25 cm distance for 5 min. The mutants tolerant to carbendazim were screened out by adding the fungicide into PDA medium, which increased resistance to the fungicide 100 times higher than their original isolates and showed auxotrophic. Three mutants,G7n,G20n and G5n, grew very well on PDA and a basic medium with hot pepper root exudation. Therefore, these mutants could be used as the isolates with good colonization ability for further research.展开更多
Syntheses of zince oxide（ZnO） nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry（XRD）, transmission electron...Syntheses of zince oxide（ZnO） nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry（XRD）, transmission electron microscopy（TEM）, infrared spectroscopy（IR） and UV-Vis spectroscopy. The prepared ZnO nanoparticles were nearly spherical and highly crystalline with an average size of 29 nm. In addition, high UV-light absorption properties of oleic acid surface modified ZnO nanoparticles were successfully obtained for a dispersion of ZnO nanoparticles in ethanol.展开更多
We investigated the effects of Si-layer-thickness ratios on ultraviolet (UV) peak intensities of Si/ SiO2 multilayered films produced by alternately stacking several-nanometer-thick Si and SiO2 layers using radio-freq...We investigated the effects of Si-layer-thickness ratios on ultraviolet (UV) peak intensities of Si/ SiO2 multilayered films produced by alternately stacking several-nanometer-thick Si and SiO2 layers using radio-frequency sputtering for the first time. The Si-layer-thickness ratio of the Si/SiO2 film is a very important parameter for enhancing the peak intensity because the ratio is concerned with the size of Si nanocrystals in the film, which might affect the intensity of the UV light emission from the film. We prepared seven samples with various estimated Si-layer-thickness ratios, and measured the photoluminescence spectra of the samples after annealing at 1150°C, 1200°C, or 1250°C for 25 min. From our experiments, we estimate that the proper Si-layer-thickness ratio to obtain the strongest UV peaks from the Si/SiO2 multilayered films is around 0.29. Such a UV-lightemitting thin film is expected to be used in future higher-density optical-disk systems.展开更多
PGMR ( Photoperiod sensitive Genic Male-sterile Rice) Nongken 58s was discovered in1973 by SHI Mingsong, with the characters ofpollen sterile under long daylength(LD) condi-tion but fertile under short daylength (SD)c...PGMR ( Photoperiod sensitive Genic Male-sterile Rice) Nongken 58s was discovered in1973 by SHI Mingsong, with the characters ofpollen sterile under long daylength(LD) condi-tion but fertile under short daylength (SD)condition during its fertility change stage. LI展开更多
To explore the method of evaluating the soothing effect of human skin damage,a human skin damage model was established using UV light induction.Four test areas were set up,namely blank control area,UV damage preventio...To explore the method of evaluating the soothing effect of human skin damage,a human skin damage model was established using UV light induction.Four test areas were set up,namely blank control area,UV damage prevention and soothing area,immediate soothing area after UV damage and soothing area after UV damage.Five skin parameters,including skin melanin,red pigment value,skin pigmentation value,a*value,and skin redness value,were used to characterize skin pigmentation before and after using the sample Changes in properties such as skin erythema and skin pigment.The results showed that the method showed significant changes in the skin condition of volunteers before and after using the sample,and could achieve a soothing effect,which has certain reference significance.展开更多
LED UV油墨利用LED光源进行光固化,光扩散粉可快速固化,在紫外光的照射下迅速发生聚合反应。将光扩散粉高分子结晶材料加入乳液合成的LED UV光固化树脂中,利用两者的有效结合,达到理想的光扩散。光固化工艺保证显示面板膜层更稳定,减少...LED UV油墨利用LED光源进行光固化,光扩散粉可快速固化,在紫外光的照射下迅速发生聚合反应。将光扩散粉高分子结晶材料加入乳液合成的LED UV光固化树脂中,利用两者的有效结合,达到理想的光扩散。光固化工艺保证显示面板膜层更稳定,减少原材料消耗,降低了生产成本。展开更多
文摘This study assessed the feasibility of developing a machine vision system equipped with ultraviolet (UV) light, using changes in fish-surface color to predict aerobic plate count (APC, a standard freshness indicator) during storage. The APC values were tested and images of the fish surface were taken when fish were stored at room temperature. Then, images</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">’</span></span></span><span><span><span><span> color-space conversion among RGB, HSV, and L*a*b* color spaces was carried out and analyzed. The results revealed that a* and b* values from the UV-light image decreased linearly during storage. A further regression analysis of these two parameters with APC value demonstrated a good exponential relationship between the a* value and the APC value (R</span><sup><span>2</span></sup><span> = 0.97), followed by the b* (R</span><sup><span>2</span></sup><span> = 0.85). Therefore, our results suggest that the change in color of the fish surface under UV light can be used to assess fish freshness during storage.
文摘Understanding chemical transformations of contaminants and the resulting products is extremely important in devising proper monitoring methods for such contaminants and in assessing potential human exposure to the transformation products in the environment. Ultraviolet (UV) light from the sun can induce various photochemical transformations of contaminants in the environment. Alkylnaphthalenes are light-molecular-weight polycyclic aromatic hydrocarbons (PAHs) which are one of the most widespread organic pollutants present in ambient air as a result of a variety of incomplete combustion sources. In this study, 1-methylnapthalene,a typical example of an alkylnaphthalene, was subjected to UV irradiation to investigate its transformation in the presence and absence of air. Twenty-one products were detected in the reaction mixtures. Some photo-oxidation products were identified, including both ring-opened and ring-retained oxygenated compounds, such as 1-naphthaldehyde, 1-naphthoic acid, 1-naphthalenemethanol and phthalic anhydride. Although dimeric products were observed in the presence of air, more were found in the presence of helium or argon gas, indicating a different photo-oxidation pathway from those commonly observed in other media, such as water. Under just 48 hours of exposure to the UV light in the presence of air, three major products were formed with a production yield of about 10% each. Compared to 1-methylnapthalene, the UV induced transformation products observed in this study are more volatile, acidic, water soluble or toxic. The formation of these products may significantly change our understanding of the risks assessed solely from the parent compound in contaminants research and supports the inclusion of airborne transformations of the parent compound in risk assessment.
文摘Based on previous work, it has been hypothesized that the energetics of ultraviolet (UV) light disrupts effects induced by receptor-binding ligands. If this hypothesis is true, then UV light should (i) disrupt a broad variety of endpoints and (ii) disrupt effects produced by ligands that bind to diverse receptor types. This was tested directly in the present study by using ligands selective for four different receptors (one ionotropic, three metabotropic) and three different behavioral endpoints. The selective dopamine D2 receptor antagonist (–)sulpiride (0.1 uM) dose-relatedly decreased spontaneous locomotor velocity, the selective nicotinic acetylcholine receptor agonist nicotine (1, 3, 5 mM) and the selective muscarinic acetylcholine receptor agonist pilocarpine (20, 30, 50 mM) induced seizure-like activity, and the selective-opioid receptor agonist U-50,488H (10 uM) produced physical dependence (manifested as abstinence-induced withdrawal) in planarian models. Each of these diverse ligand and receptor-mediated effects were attenuated by UV light (254 nm = 7.83 × 10–19 J = 4.89 eV). These findings provide further evidence that UV light disrupts ligand-receptor mediated interactions and that UV light might provide a useful tool for examining drug-receptor interactions.
文摘After comparison of Trichoderma population density and test of colonization ability in rhizospheres were conducted. Auxotrophic mutants of T. harzianum tolerant to carbendazim and UV-light were obtained by UV-light mutagenesis and carbendazim stress on PDA medium and a basis medium with hot pepper root exudation by adding the fungicide. The results showed: all four different isolates of Trichoderma had certain colonization ability in rhizosphere with the characteristic of growing as roots and distributing many more around root tips. The ability, however, was different for the 4 isolates, showing the wild isolates colonized weakly in rhizosphere. Around 5% spores alive and mutants could be obtained after the isolates were irradiated under a 20W UV-light at 25 cm distance for 5 min. The mutants tolerant to carbendazim were screened out by adding the fungicide into PDA medium, which increased resistance to the fungicide 100 times higher than their original isolates and showed auxotrophic. Three mutants,G7n,G20n and G5n, grew very well on PDA and a basic medium with hot pepper root exudation. Therefore, these mutants could be used as the isolates with good colonization ability for further research.
基金Supported by the Key Project of the National Eleventh Five-Year Research Programe of China(No.2008BAE66B00)
文摘Syntheses of zince oxide（ZnO） nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry（XRD）, transmission electron microscopy（TEM）, infrared spectroscopy（IR） and UV-Vis spectroscopy. The prepared ZnO nanoparticles were nearly spherical and highly crystalline with an average size of 29 nm. In addition, high UV-light absorption properties of oleic acid surface modified ZnO nanoparticles were successfully obtained for a dispersion of ZnO nanoparticles in ethanol.
基金The financial support from the National Nature Science Foundation of China （No. 10835008） and State Key Laboratory of Coal Conversion （SKLCC） in-house project （No. 2008BWZ011） were highly acknowledged.
文摘We investigated the effects of Si-layer-thickness ratios on ultraviolet (UV) peak intensities of Si/ SiO2 multilayered films produced by alternately stacking several-nanometer-thick Si and SiO2 layers using radio-frequency sputtering for the first time. The Si-layer-thickness ratio of the Si/SiO2 film is a very important parameter for enhancing the peak intensity because the ratio is concerned with the size of Si nanocrystals in the film, which might affect the intensity of the UV light emission from the film. We prepared seven samples with various estimated Si-layer-thickness ratios, and measured the photoluminescence spectra of the samples after annealing at 1150°C, 1200°C, or 1250°C for 25 min. From our experiments, we estimate that the proper Si-layer-thickness ratio to obtain the strongest UV peaks from the Si/SiO2 multilayered films is around 0.29. Such a UV-lightemitting thin film is expected to be used in future higher-density optical-disk systems.
文摘PGMR ( Photoperiod sensitive Genic Male-sterile Rice) Nongken 58s was discovered in1973 by SHI Mingsong, with the characters ofpollen sterile under long daylength(LD) condi-tion but fertile under short daylength (SD)condition during its fertility change stage. LI
文摘To explore the method of evaluating the soothing effect of human skin damage,a human skin damage model was established using UV light induction.Four test areas were set up,namely blank control area,UV damage prevention and soothing area,immediate soothing area after UV damage and soothing area after UV damage.Five skin parameters,including skin melanin,red pigment value,skin pigmentation value,a*value,and skin redness value,were used to characterize skin pigmentation before and after using the sample Changes in properties such as skin erythema and skin pigment.The results showed that the method showed significant changes in the skin condition of volunteers before and after using the sample,and could achieve a soothing effect,which has certain reference significance.
