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Anti-ultraviolet aging tests of asphalts adapting to environment in Tibetan Plateau of China 被引量:15
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作者 廖公云 黄晓明 巴桑顿珠 《Journal of Southeast University(English Edition)》 EI CAS 2008年第4期503-507,共5页
Ultraviolet (UV) aging is one of the main factors which cause premature damage of asphalt pavements in the Tibetan Plateau, China. According to the measured levels of UV radiation, aging tests of styrene-butadiene r... Ultraviolet (UV) aging is one of the main factors which cause premature damage of asphalt pavements in the Tibetan Plateau, China. According to the measured levels of UV radiation, aging tests of styrene-butadiene rubber (SBR) asphalts with different contents of three anti-UV-aging agents including nano-TiO2, CeO2 and carbon black are performed. Common indices, which include retained penetration after thin film oven tests (TFOT) and softening point, and strategic highway research program (SHRP) indices of aged asphalts are evaluated. Infrared absorption spectral analysis is performed on asphalt specimens with 0. 8% carbon black which have been aged for different aging times (500, 1000 and 1 500 h). By grey incidence analysis, the optimal contents of anti-UV-aging agents are determined. The results show that TiO2 and CeO2 are not only good UV absorbing or shielding agents, but also strong oxidants. Carbon black is a good anti-UV-aging agent, and its optimal content is about 0. 8% of asphalt weight. UV aging of asphalt mainly occurs in the early stages of aging. The longer the aging time, the more severe the aging of asphalt. 展开更多
关键词 ultraviolet (UV) aging agent carbon black infrared absorption spectral analysis grey incidence analysis
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Effect of Ultraviolet Aging on the Bonding and Tensile Properties of Polymer-Cement Composite 被引量:6
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作者 Zhihang Wang Jinyu Xu +1 位作者 Xin Meng Congjin Zhu 《Journal of Renewable Materials》 SCIE EI 2021年第6期1157-1168,共12页
In this paper,the specimens of polymer-cement composites after 1 d,7 d,15 d,and 30 d aging without aging and UV aging are subjected to fixed extension test and tensile test.By observing the mode of the composite in th... In this paper,the specimens of polymer-cement composites after 1 d,7 d,15 d,and 30 d aging without aging and UV aging are subjected to fixed extension test and tensile test.By observing the mode of the composite in the fixed-elongation test,and measuring the elastic recovery rate,tensile strength,elongation at break,peak tensile strain,tensile toughness and pre-peak tensile toughness of the composite,the effects of UV aging on the bonding and the tensile properties of the composite were studied.And combining with scanning electron microscopy experiments,the micro-mechanism of the effect of ultraviolet aging on the properties of composite was analyzed.The results showed that the composite had a good bonding property,and no damage was observed after UV aging for 30 days.The UV aging increased the elastic recovery rate and peak tensile within a certain range.The elastic recovery rate and peak tensile strain of the composite increased by 6.60%and 23.55%respectively after UV aging for 15 days.Therefore,the UV aging could enhance the tensile property and the tensile energy consumption performance of the composite.The tensile strength of the composite increased by 65.36%after UV aging for 30 days.The tensile toughness and pre-peak tensile toughness of the composite were increased by 43.29%and 101.83%respectively after UV aging for 15 days.The elongation at break of composite decreased continuously after UV aging due to the photo-oxygen reaction,as well as secondary hydration reaction and cross-linking curing reaction of cement. 展开更多
关键词 Polymer-cement composite ultraviolet aging bonding property tensile property failure mode MICROSTRUCTURE
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Evaluation of the in vitro antimicrobial properties of ultraviolet A/riboflavin mediated crosslinking on Candida albicans and Fusarium solani 被引量:2
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作者 Bing Sun Zhi-Wei Li +3 位作者 Hai-Qun Yu Xiang-Chen Tao Yong Zhang Guo-Ying Mu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2014年第2期205-210,共6页
AIMTo evaluate the antimicrobial properties of ultraviolet A (UVA) (365 nm)/riboflavin against Candida albicans and Fusarium solani.
关键词 aNTIMICROBIaL CROSSLINKING FUNGaL RIBOFLaVIN ultraviolet a
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Promising Ultraviolet Absorbers——Novel Guanine Analogs Having Significantly Improved Ultraviolet Absorption Capacity and Dissipating the Energy of Absorbed Photons by Nonradiative Decay Mechanism 被引量:1
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作者 HAN Song-zhe WU Yu-ting +1 位作者 ZHANG Meng JIAO Jia-jun 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2012年第3期434-437,共4页
Structural properties of nucleobase underlie their ultrafast excited-state dynamics and low fluorescence quantum yields, which cause effectively nonradiative decay process and render them like sunscreens. Thus, eight ... Structural properties of nucleobase underlie their ultrafast excited-state dynamics and low fluorescence quantum yields, which cause effectively nonradiative decay process and render them like sunscreens. Thus, eight guanine analogs[N-2-(2'-nitrobenzoyl)-guanine, N-2-(3'-nitrohenzoyl)-guanine, N-2-(4'-nitrobenzoyl)-guanine, N-2-(2'-hydroxybenzoyl)-guanine, N-2-(4'-methoxylbenzoyl)-guanine, N-2-(4'-chloricbenzoyl)-guanine, N-2-(4'- me- thylicbenzoyl)-guanine and N-2-(3',5'-dinitrobenzoyl)-guanine] with different substituted benzoyls, except N-2-(4'-chloricbenzoyl)-guanine, were newly synthesized. In contrast with guanine, they exhibit wider ultraviolet absorbent range, higher molar extinction coefficient and lower fluorescence intensity. 展开更多
关键词 GUaNINE ultraviolet absorber acidamide
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Ultraviolet and mid-infrared continuum generation by cross-phase modulation between red-shifted solitons and blue-shifted dispersive waves in a photonic crystal fiber 被引量:1
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作者 申向伟 苑金辉 +7 位作者 桑新柱 余重秀 饶岚 忻向军 夏民 韩颖 夏长明 侯蓝田 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第7期337-342,共6页
Using a photonic crystal fiber with a zero dispersion wavelength of the fundamelItal mode at 780 nm designed and fabricated in our lab, the ultraviolet and mid-infrared continua are generated by cross-phase modulation... Using a photonic crystal fiber with a zero dispersion wavelength of the fundamelItal mode at 780 nm designed and fabricated in our lab, the ultraviolet and mid-infrared continua are generated by cross-phase modulation between red-shift solitons and blue-shift dispersive waves. The dependences of continuum on the pump power and wavelength are investigated. With the pump working at 820 nm, when the pump power increases froul 300 to 500 mW, the bandwidths of ultraviolet and mid-infrared continua change from 80 to 140 nm and 100 to 200 nm, respectively. The wavelength of ultraviolet continuum is below 246 nm, and the wavelength of mid-infrared continuum exceeds 2500 nm. Moreover, the influences of pump power on wavelength and conversion efficiency of different parts of continua are also demonstrated. 展开更多
关键词 photonic crystal fiber (PCF) ultraviolet and mid-infrared continuum fundamentalmode soliton self-frequency shift
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STUDIES ON THE EFFECT OF DISSOLVED IONS ON SCO DEPRESSING PROPERTY USING ULTRAVIOLET ABSORPTION SPECTRA
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作者 邵绪新 皇甫京华 +1 位作者 何维军 郭梦熊 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1996年第2期16-24,共9页
SCO is a selective dolomite deperessant in the flotation system of collophane and dolomite. However,experi-ments confirmed that reverse phenomenon would occur for some phosphatic mines. In order to explain the SCO dep... SCO is a selective dolomite deperessant in the flotation system of collophane and dolomite. However,experi-ments confirmed that reverse phenomenon would occur for some phosphatic mines. In order to explain the SCO depress-ing mechanism i this paper describes studying results on the ef-fect of dissolved ions on SCO depressing property using ul-traviolet absorption spectra. It is found that the effect of dis-solved ions, especially Mg2+ ?on the SCO adsorption property is strong. When Mg2+ concentration is low,dolomite adsorbs SCO and is depressed. When Mgz+ concentration is more than 90g/t in pulp.SCO adsorption capacity on colophane is obvi-ously greater than that on dolomite,which results in the de-pression of collophane. The adsorption results are consistent with flotation results. 展开更多
关键词 SCO depressing property ultraviolet absorption spectra
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Effect of Ultraviolet Aging on Asphalt Rheological Properties
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作者 Wang Jiani Xue Zhongjun +1 位作者 Tan Yiqiu Zhang Lei 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2013年第4期26-32,共7页
This paper simulated the ultraviolet aging process of asphalt and used dynamic mechanic analysis (DMA) method to evaluate the effect of ultraviolet aging on the asphalt theological properties. After having experienc... This paper simulated the ultraviolet aging process of asphalt and used dynamic mechanic analysis (DMA) method to evaluate the effect of ultraviolet aging on the asphalt theological properties. After having experienced ultravio- let aging, the low temperature performance of asphalt binder decreased significantly, with its complex modulus increased and phase angle decreased along with changing rheological properties as compared to the performance of original asphalt binder. The ultraviolet aging process would make asphalt binder more sensitive to brittle and fatigue failure. On the basis of the time-temperature superposition principle (TTSP), the viscoelastic transition frequency (coT) is proposed to evaluate the effect of ultraviolet aging. It is found that with the increase in ultraviolet aging time, the cox moves to the lower frequency range gradually. Since the viscoelastic transition frequency is sensitive to the effect of aging, it can be used as an indicator of ultraviolet aging. 展开更多
关键词 aSPHaLT ultraviolet aging rheological properties viscoelastic transition frequency
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Higher order harmonics suppression in extreme ultraviolet and soft x-ray
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作者 陈勇 魏来 +6 位作者 钱凤 杨祖华 王少义 巫殷忠 张强强 范全平 曹磊峰 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期344-348,共5页
The extreme ultraviolet and soft x-ray sources are widely used in various domains. Suppressing higher order harmonics and improving spectral purity are significant. This paper describes a novel method of higher order ... The extreme ultraviolet and soft x-ray sources are widely used in various domains. Suppressing higher order harmonics and improving spectral purity are significant. This paper describes a novel method of higher order harmonics suppression with single order diffraction gratings in extreme ultraviolet and soft x-ray. The principle of harmonic suppression with single order diffraction grating is described, and an extreme ultraviolet and soft x-ray non-harmonics grating monochromator is designed based on the single order diffraction grating. The performance is simulated by an optical design software. The emergent beams of a monochromator with different gratings are measured by a transmission grating spectrometer. The results show that the single order diffraction grating can suppress higher order harmonics effectively, and it is expected to be widely used in synchrotron radiation, diagnostics of laser induced plasma, and astrophysics. 展开更多
关键词 higher order harmonics suppression extreme ultraviolet and soft x-ray monochromator single order diffraction grating
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Effect of a Single Threading Dislocation on Electrical and Single Photon Detection Characteristics of 4H-SiC Ultraviolet Avalanche Photodiodes 被引量:5
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作者 Lin-Lin Su Dong Zhou +5 位作者 Qing Liu Fang-Fang Ren Dun-Jun Chen Rong Zhang You-Dou Zheng Hai Lu 《Chinese Physics Letters》 SCIE CAS CSCD 2020年第6期119-122,共4页
We fabricated 4H-SiC ultraviolet avalanche photodiode(APD)arrays and systematically investigated the effect of threading dislocations on electrical and single photon detection characteristics of 4H-SiC APDs.Based on a... We fabricated 4H-SiC ultraviolet avalanche photodiode(APD)arrays and systematically investigated the effect of threading dislocations on electrical and single photon detection characteristics of 4H-SiC APDs.Based on a statistical correlation study of individual device performance and structural defect mapping revealed by molten KOH etching,it is determined with high confidence level that even a single threading dislocation within APD active region would lead to apparent device performance degradation,including increase of dark current near breakdown voltage,premature breakdown and reduction of single photon detection efficiency at fixed dark count rate. 展开更多
关键词 BREaKDOWN ultraviolet aPPaRENT
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Preparation and Anti-ultraviolet Aging Performance of Organic Layered Double Hydroxides/Bitumen Composites 被引量:3
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作者 XU Song YU Jianying +2 位作者 KE Yunbin XUE Lihui HU Changbin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2019年第4期979-986,共8页
Layered double hydroxides(LDHs) with the physical property of high ultraviolet(UV)reflectance were used to enhance the anti-UV aging performance of bitumen. In view of the poor compatibility of LDHs with bitumen, thre... Layered double hydroxides(LDHs) with the physical property of high ultraviolet(UV)reflectance were used to enhance the anti-UV aging performance of bitumen. In view of the poor compatibility of LDHs with bitumen, three organic anions, namely, sodium dodecyl benzenesulfonate(SDBS), sodium dodecyl sulfate(SDS) and sodium dodecyl sulfonate(SDSO), were used as modifiers to prepare organic LDHs(OCLDHs) through regeneration process, and the crystal structure, chemical composition, morphological feature and UV shielding capability of synthesized OCLDHs were analyzed. Then the OCLDHs were added into bitumen to evaluate the storage stability and anti-UV aging property of OCLDHs/bitumen composites.The results show that the organic anions are inserted into the interlayers of LDHs, the intercalation expands the interlayer distance of LDHs, makes the particle shapes become more irregular and complicated, and enhances the absorption ability within the range from 200 to 300 nm while has little influence on the UV reflection ability.Result of high temperature storage stability indicates the organic modification ameliorates the compatibility of LDHs with bitumen. Compared with LDHs, OCLDHs decrease the deteriorations of bitumen’s properties during UV exposure test, exhibiting better effect in enhancing anti-UV aging performance of bitumen. Furthermore,among the three OCLDHs, LDHs intercalated by SDBS exhibit the most effective improvement due to the best compatibility with bitumen and comparatively good UV shielding effect. 展开更多
关键词 LaYERED double HYDROXIDES BITUMEN ORGaNIC modification compatibility ultraviolet aging performance
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Laboratory research on rheological behavior and characterization of ultraviolet aged asphalt 被引量:3
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作者 吴少鹏 朱国军 +1 位作者 陈筝 刘至飞 《Journal of Central South University》 SCIE EI CAS 2008年第S1期369-373,共5页
The influence of aging on the evolution of structural,morphological and rheological properties of neat asphalt was investigated by Fourier transform infrared(FTIR),atomic force microscopy(AFM) and dynamic shear rheome... The influence of aging on the evolution of structural,morphological and rheological properties of neat asphalt was investigated by Fourier transform infrared(FTIR),atomic force microscopy(AFM) and dynamic shear rheometer(DSR),respectively.Asphalt was suffered under 20 W/m2 of UV radiant intensity and under the condition of aging time(0,48,96 and 144 h) with film thickness of 100 μm and film thickness of 50,100,200 and 500 μm after aging for 120 h,respectively,at certain UV radiant intensity 20 W/m2.Rheological results tested by DSR exhibit higher the complex shear(stiffness) modulus(G*) and lower phase angle(δ),compared to the virgin at the same test condition.The compositions analysis of asphalt before and after aging show an increase of carbonyl and sulfoxides,while a decrease of aromatic functional groups.With the increase of the component of asphaltene,obvious agglomerates of asphalten appear in neat asphalt surfaces after aging. 展开更多
关键词 ultraviolet(UV) aGING aSPHaLT RHEOLOGICaL behavior chemical microstructure MORPHOLOGY EVOLUTIONS
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Ground-based Observations of Ultraviolet and Total Solar Radiation in Shenyang,Northeast China 被引量:2
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作者 GAO Qian HU LiWen +6 位作者 GONG HuiZhi GAO Na YU JiaMing WANG Yang CHU Chun YANG Hui LIU Yang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2011年第5期499-505,共7页
Objective This work explores the diurnal variation of Solar ultraviolet radiation (UVR) and total solar radiation (TSR) in northeast China,using daily observations of UVR and TSR in Shenyang.Methods UVR and TSR me... Objective This work explores the diurnal variation of Solar ultraviolet radiation (UVR) and total solar radiation (TSR) in northeast China,using daily observations of UVR and TSR in Shenyang.Methods UVR and TSR measurements were carried out from March 1st,2006 to December 31st,2009 in Shenyang,Liaoning province,China (41°51' N,123°27' E).Results Both TSR and UVR showed seasonal variation,reaching the highest levels in summer and the lowest in winter.They showed the greatest fluctuation in summer and autumn.The irradiance of TSR and UVR on clear days around the equinoxes and solstices increased substantially compared with the mean seasonal irradiance,especially in autumn.The whole day accumulated dose of UVR in winter was far less than that during the middle part of a summer day (i.e.between 10:00 and 14:00).It was also less than the accumulated summer dose of morning and afternoon (i.e.between 8:00 and 10:00 and 14:00 and 16:00).Conclusion The instant irradiance and daily accumulated amount of UVR are low in Shenyang,especially in autumn and winter.Thus concern about the health effects arising because shortage of UVR in northeast China is warranted. 展开更多
关键词 ultraviolet radiation Total sun radiation Broadband radiometer
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Comprehensive Evaluation on Impacts of Diseases on Quality of Paris polyphylla var. chinensis Based on Ultraviolet and Infrared Spectra 被引量:1
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作者 Yongxia KE Jixiu SHEN +3 位作者 Hairong ZHONG Risha WEIZE Yunzhang XU Yuan LIU 《Medicinal Plant》 CAS 2019年第3期63-65,68,共4页
[Objectives] The research aimed to evaluate impacts of diseases on quality of Paris polyphylla var. chinensis. [Methods]Ultraviolet spectrophotometry was used to determine and contrast content of total saponins in roo... [Objectives] The research aimed to evaluate impacts of diseases on quality of Paris polyphylla var. chinensis. [Methods]Ultraviolet spectrophotometry was used to determine and contrast content of total saponins in root,stem and leaf from healthy and diseased plants. Infrared characteristic absorption peaks of healthy and diseased plants were found by infrared fingerprint method for comparative analysis.[Results]Total saponins content in root sample J4 of healthy plant reached 4. 89% and was the highest,while it was 0. 13% in stem sample J11 of healthy plant and was the lowest. Total saponins content in root sample B1 of diseased plant was 1. 68% and was the highest,while it was 0. 1% in stem sample B7 of diseased plant and was the lowest. In healthy and diseased plants,total saponins content in root was significantly higher than that in stem and leaf. Content of total saponins in root from healthy plant was significantly higher than that from diseased plant,and there was little difference in stem and leaf of healthy and diseased plants. Root sample Jg of healthy plant had obvious C-O characteristic vibration of polysaccharides and glycosides and absorption peak of O-H bending vibration in steroidal saponin near 1 160. 02 cm-1,while diseased plant had no obvious absorption peak. Near 861. 97 and 768. 07 cm-1,root sample Jg of healthy plant had significant C-C stretching vibration in sugar ring and characteristic absorption peak of characteristic vibration of steroidal saponin,while root sample Bg of diseased plant had no obvious characteristic peak. [Conclusions] Diseases significantly affected composition and content of total saponins and steroidal saponins from P. polyphylla var. chinensis,further affecting quality of P. polyphylla var. chinensis. 展开更多
关键词 PaRIS polyphylla VaR. CHINENSIS ultraviolet Infrared Total SaPONINS QUaLITY
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Preparation and Characterization of Lignosulfonate Intercalated Layered Double Hydroxides and Their Application in Improving Ultraviolet Aging Resistance for Bitumen
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作者 何边阳 余剑英 +2 位作者 HU Wei WAN Xiaodong WU Zhongkui 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2019年第2期446-452,共7页
In order to develop economically anti-ultraviolet(UV) aging additives to bitumen and extend the comprehensive utilization of lignin materials, lignosulfonate(LS) was selected to intercalate into layered double hydroxi... In order to develop economically anti-ultraviolet(UV) aging additives to bitumen and extend the comprehensive utilization of lignin materials, lignosulfonate(LS) was selected to intercalate into layered double hydroxides(LDHs), then the LS intercalated LDHs(LS-LDHs) were applied to improve UV aging resistance of bitumen. With the characterization of X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, chemical analysis and scanning electron microscopy(SEM), LS was successfully intercalated into the galleries of LDHs. The ultraviolet and visible(UV-vis) absorbance curves showed LS-LDHs had excellent UV absorptive ability from 200 to 400 nm. Thermogravimetry and differential scanning calorimetry(TG-DSC) indicated LS-LDHs could have a good thermal stability during the processing of bitumen. Compared with the LDHs, the LS-LDHs exhibited better performance in UV aging resistance of bitumen. 展开更多
关键词 LaYERED double HYDROXIDES LIGNOSULFONaTE BITUMEN ultraviolet aging resistance
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Mutagenesis of T richoderma V iride by Ultraviolet and Plasma
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作者 姚日生 李曼曼 +3 位作者 邓胜松 胡华佳 王淮 李凤和 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第4期353-356,共4页
Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet (UV) and plasma mutation. The mutant produced a 21.0... Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet (UV) and plasma mutation. The mutant produced a 21.0 IU/mL FPase which was 98.1% higher than that of the parent strain Trichoderma viride ZY-1. In addition, the effect of ultraviolet and plasma mutagenesis was not merely simple superimposition of single ultraviolet mutation and single plasma mutation. Meanwhile, there appeared a capsule around some of the spores after the ultraviolet and plasma treatment, namely, the spore surface of the strain became fuzzy after ultraviolet or ultraviolet and plasma mutagenesis. 展开更多
关键词 MUTaGENESIS Trichoderma viride PLaSMa ultraviolet CELLULaSE solid-statefermentation
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Effects of polypeptide from Chlamys farreri on amino acid con-tent in guinea pig skin irradiated by chronic ultraviolet A and B
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作者 于国英 曹鹏利 +3 位作者 郭昆 王跃军 孙谧 王春波 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2004年第4期440-442,共3页
We examined the effects of polypeptide from Chlamys farreri (PCF) on the amount of hy-droxyproline in guinea pig skin irradiated by chronic ultraviolet A (UVA) and ultraviolet B (UVB) radiation. PCF was applied locall... We examined the effects of polypeptide from Chlamys farreri (PCF) on the amount of hy-droxyproline in guinea pig skin irradiated by chronic ultraviolet A (UVA) and ultraviolet B (UVB) radiation. PCF was applied locally before repeated exposure of guinea pig to UVA and UVB. The contents of hy-droxyproline and other amino acids in guinea pig skin were determined by automatic amino acid analyzer. Our results showed that: (1) long-time UVA and UVB radiation can reduce dramatically the amounts of hy-droxyproline, aspartic acid, threonine, glycine, phenylalanine and lysine in guinea pig skin in comparison with the control group (P < 0.05); (2) Compared with model group, pre-treatment with 5 % and 20 % PCF prior to UVA and UVB radiation can inhibit the decline of amino acids content in guinea pig skin in a dose-dependent manner (P < 0.05). As the decrease of hydroxyproline, glycine and lysine contents in the skin directly reflexes type I collagen degeneration, our results indicated that the chronic application of PCF can protect skin type I collagen against UV radiation, and thus protect skin from photoaging. 展开更多
关键词 polypeptide from Chlamys farreri ultraviolet radiation HYDROXYPROLINE PHOTOaGING guinea pig
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Three-Photon Resonant Third Harmonic Generation of H2 in Vacuum Ultraviolet and Extreme Ultraviolet Regions
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作者 XIE Xiao-bo WANG Peng-qian +1 位作者 CAO Chuan-shun SUN Tao-heng 《Chinese Physics Letters》 SCIE CAS CSCD 1999年第11期816-818,共3页
Tunable coherent vacuum ultraviolet and extreme ultraviolet radiation have been produced in H2 by three-photon resonant third harmonic generation via B1 Σ_(u)^(+)(v’) ← X^(1) Σ_(g)^(+) (v = 0 ) and C^(1) IIu(v’) ... Tunable coherent vacuum ultraviolet and extreme ultraviolet radiation have been produced in H2 by three-photon resonant third harmonic generation via B1 Σ_(u)^(+)(v’) ← X^(1) Σ_(g)^(+) (v = 0 ) and C^(1) IIu(v’) ← X^(1) Σ_(g)^(+) ( v = 0 ) transitions. Highly resolved third harmonic spectrum exhibits some distinct characteristics. Phase-matching effect of the nonlinear optical process is also discussed. 展开更多
关键词 ultraviolet HaRMONIC RESONaNT
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Feasibility of Extreme Ultraviolet Active Optical Clock
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作者 ZHUANG Wei CHEN Jing-Biao 《Chinese Physics Letters》 SCIE CAS CSCD 2011年第8期28-30,共3页
We propose an experimental scheme of vacuum ultraviolet(VUV)and extreme ultraviolet(XUV)optical frequency standards with noble gas atoms.Considering metastable state 3𝑃2 noble atoms pumped by a conventional di... We propose an experimental scheme of vacuum ultraviolet(VUV)and extreme ultraviolet(XUV)optical frequency standards with noble gas atoms.Considering metastable state 3𝑃2 noble atoms pumped by a conventional discharging method,the atomic beam is collimated with transverse laser cooling at the metastable state and enters into the laser cavity in the proposed setup.Due to stimulated emission from the metasable state to the ground state inside the laser cavity consisting of VUV reflection coating mirrors,our calculations show that with enough population inversion to compensate for the cavity loss,an active optical frequency standard at VUV and XUV is feasible. 展开更多
关键词 PUMPED CaVITY ultraviolet
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Lentinula edodes extract inhibits matrix metalloproteinase expression and increases typeⅠprocollagen expression via the p38 MAPK/c-Fos signaling pathway in ultraviolet A and B-irradiated HaCaT keratinocytes
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作者 Jung Im Lee Jung Hwan Oh +6 位作者 Fatih Karadeniz So Young Park Hye Ran Kim Hyun Jin Jo Kyung Im Jung Byung-Jin Jeon Chang-Suk Kong 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2021年第4期164-173,共10页
Objective:To determine the effect of Lentinula edodes extract on ultraviolet(UV)A and UVB-induced changes in matrix metalloproteinase(MMP)and type I procollagen expression using human immortalized HaCaT keratinocytes.... Objective:To determine the effect of Lentinula edodes extract on ultraviolet(UV)A and UVB-induced changes in matrix metalloproteinase(MMP)and type I procollagen expression using human immortalized HaCaT keratinocytes.Methods:Lentinula edodes ethanol extract(LEE)was obtained by extraction with 80%ethanol for 4 h at 80℃.Effect of LEE on UVinduced alteration on the expression and production of MMPs and type I procollagen in keratinocytes was investigated using ELISA,RT-PCR,and Western blotting assay.To determine the underlying mechanism of LEE-mediated effects,mitogen-activated protein kinase(MAPK)and activator protein 1 signaling pathways were analysed by Western blotting assay.Results:LEE significantly inhibited the expression of MMP-1 and MMP-9 and increased the expression of type I procollagen in UVA and UVB-irradiated HaCaT keratinocytes.The phosphorylation levels of p38 were significantly inhibited by LEE whereas it did not affect c-Jun N-terminal kinase and extracellular signal-regulated kinase phosphorylation.Suppression of p38 phosphorylation was also accompanied by downregulation of UVA and UVB-induced increase in c-Fos.Conclusions:LEE effectively inhibits the expression of MMP-1 and MMP-9 and increases type I procollagen production through the p38 MAPK/c-Fos signaling pathway in UVA and UVB-irradiated HaCaT keratinocytes.This findings suggest that Lentinula edodes may be developed as a cosmetic material to suppress UV exposuremediated skin aging. 展开更多
关键词 Lentinula edodes ultraviolet Matrix metalloproteinases TypeⅠprocollagen Ha Ca T
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Deep-ultraviolet and visible dual-band photodetectors by integrating Chlorin e6 with Ga_(2)O_(3)
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作者 Yue Zhao Jin-Hao Zang +5 位作者 Xun Yang Xue-Xia Chen Yan-Cheng Chen Kai-Yong Li Lin Dong Chong-Xin Shan 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第7期631-635,共5页
Gallium oxide(Ga_(2)O_(3))is a promising material for deep-ultraviolet(DUV)detection.In this work,Chlorin e6(Ce6)has been integrated with Ga_(2)O_(3)to achieve a DUV and visible dual-band photodetector,which can achie... Gallium oxide(Ga_(2)O_(3))is a promising material for deep-ultraviolet(DUV)detection.In this work,Chlorin e6(Ce6)has been integrated with Ga_(2)O_(3)to achieve a DUV and visible dual-band photodetector,which can achieve multiple target information and improve the recognition rate.The photodetector shows two separate response bands at 268 nm and 456 nm.The DUV response band has a responsivity of 9.63 A/W with a full width at half maximum(FWHM)of 54.5 nm;the visible response band has a responsivity of 1.17 A/W with an FWHM of 45.3 nm.This work may provide a simple way to design and fabricate photodetectors with dual-band response. 展开更多
关键词 deep ultraviolet VISIBLE dual-band photodetector Ga_(2)O_(3)
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