期刊文献+
共找到376篇文章
< 1 2 19 >
每页显示 20 50 100
Photooxidation stability of phytosterols with different relative spatial positions in different particles
1
作者 Jingjian Liu Dan Wang +1 位作者 Ping Shao Simin Feng 《Food Innovation and Advances》 2023年第3期225-232,共8页
The aim of this study was to investigate the effects of relative spatial position of stigmasterol on its photooxidation stability in different particles.Phytosterol oxidation products(POPs)from phytosterol oxidation w... The aim of this study was to investigate the effects of relative spatial position of stigmasterol on its photooxidation stability in different particles.Phytosterol oxidation products(POPs)from phytosterol oxidation were successfully isolated and studied using solid phase extraction(SPE)technology in conjunction with GC-MS.The photooxidation stability of stigmasterol in four particles was as follows:zein stabilized particles(ZPs)≈zein-pectin stabilized particles(ZPPs)>soy protein isolate(SPI)-pectin stabilized particles(SPPs)>SPI stabilized particles(SPs).7β-Hydroxy and 5β,6β-epoxy was the main POPs in the first and second oxidation stages,respectively,which reached 8,945±43μg/g and 6,010±289μg/g after 240 min UV light exposure treatment in SPs.When stigmasterol was hydrophobically adsorbed on the surface of SPs,the network gel generated by pectin outside SPPs prevented photooxidation of stigmasterol.When stigmasterol was encapsulated in the interior of ZPs,the blocking effect of pectin in ZPPs became insignificant.The study provided a feasible development direction for the storage and quality control of phytosterols as dietary supplements. 展开更多
关键词 stability photooxidation STABILIZED
下载PDF
Physiological Basis of Photosynthetic Tolerance to Photooxidation and Shading in Rice 被引量:13
2
作者 李霞 焦德茂 《Acta Botanica Sinica》 CSCD 2000年第12期1271-1277,共7页
Thirty genotypes from rice germplasm were identified under photooxidation and shading condition and divided into four basic types : (1) cultivars tolerant to both photooxidation and shading, (2) cultivars tolerant to... Thirty genotypes from rice germplasm were identified under photooxidation and shading condition and divided into four basic types : (1) cultivars tolerant to both photooxidation and shading, (2) cultivars tolerant to photooxidation but sensitive to shading, (3) cultivars tolerant to shading but sensitive to photooxidation, and (4) cultivars sensitive to photooxidation and shading. A comparative study of photosynthetic characteristics of a cultivar (cv. Wuyujing 3) that is tolerant and a cultivar (cv. Xiangxian) that is sensitive to both photoinhibition and shading showed that the photochemical efficiency of PSⅡ ( F v/F m ) and the content of PSⅡ_D1 protein in the tolerant cultivar “Wuyujing 3” decreased less under photoinhibition conditions as compared with “Xiangxian”. Under photooxidation conditions, superoxide dismutase was induced rapidly to a higher level and the active oxygen O - built up to a lower level in “Wuyujing 3” than in “Xiangxian”. At the same time, the photosynthetic rate decreased by 23% in “Wuyujing 3” vs. 64% in “Xiangxian”. Shading (20% natural light) during the booting stage caused only small decreases (7%-13%) in RuBisCO activity and the photosynthetic rate in “Wuyujing 3” but showed marked decreases (57%-64%) in “Xiangxian” which corresponded to the decreases in grain yield in the two cultivars (38% and 73%, respectively). The correlation analysis showed that the tolerance to photooxidation is mainly related to PSⅡ_D1 and that to shading is mainly related to RuBisCO activity. This study provided a simple and effective screening method and physiological basis for crop breeding in enhancing tolerance to both high and low radiation. 展开更多
关键词 photooxidation SHADE RICE PSⅡphotochemical efficiency RuBi0
下载PDF
Characteristics of Chlorophyll Fluorescence and Membrane-lipid Peroxidation of Various High-yield Rices Under Photooxidation Conditions 被引量:4
3
作者 黄雪清 焦德茂 李霞 《Acta Botanica Sinica》 CSCD 2002年第3期279-286,共8页
Using various high-yield rices (Oryza sativa L.) such as japonica cultivar 9516, two parental line hybrid rice between subspecies with more japonica element Peiai 64/E32, Liangyoupeijiu (Peiai 64/9311), and indica hyb... Using various high-yield rices (Oryza sativa L.) such as japonica cultivar 9516, two parental line hybrid rice between subspecies with more japonica element Peiai 64/E32, Liangyoupeijiu (Peiai 64/9311), and indica hybrid rices X07S/Zihui 100, Gangyou 881, Shanyou 63 as the materials, the characteristics of chlorophyll fluorescence and membrane-lipid peroxidation of detached leaves at booting stage under photooxidation conditions were studied. In comparison with indica hybrid rice, after the photooxidation treatment, the primary photochemical efficiency of PS II (F-v/F-m), quantum yield of linear electron transport of PS II (Phi(PSII)) and photochemical quenching coefficient (qP) in japonica cultivar and hybrid rice with japonica decreased less. This indicated that high-yield rice with japonica was able to maintain higher capability of light energy conversion, resulting in the alleviation of photoinhibition. Meanwhile, the higher activities of protective enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) led to the less accumulation of endogenous active oxygen (O-(2)(radical anion), H2O2) and less content of the malondialdehyde (MDA) and the less decline of chlorophyll and protein contents, indicating a stronger tolerance to photooxidation. The changes in contents of chlorophyll and protein among various nee cultivars during photooxidation treatment were consistent with the decline of chlorophyll content from heading stage to maturation stage under natural conditions. Statistical analysis showed that there was a significant correlation between the indexes of tolerance to photooxidation and the rate of seed setting, implying that the cultivar tolerated to photooxidation had higher resistance to early aging of leaf. These results suggested that from a view of superhigh-yield breeding, considering both the utilization of heterosis and the resistance to early aging of leaf, introduction of japonica element tolerating to photooxidation into the rice sterile line (maternal plant) is a breeding strategy worthy to pay great attention to. 展开更多
关键词 RICE photooxidation chlorophyll fluorescence membrane-lipid peroxidation
下载PDF
Photooxidation in Leaves of Facultative CAM Plant Sedum spectabile at C_3 and CAM Mode 被引量:2
4
作者 林植芳 彭长连 林桂珠 《Acta Botanica Sinica》 CSCD 2003年第3期301-306,共6页
The switch from C-3 to CAM pathway was induced by water stress in a C-3/CAM intermediate plant Sedum spectabile Boreau. Typical CAM criteria were observed upon 15 d of withholding water. Leaf delta(13)C value (-%) and... The switch from C-3 to CAM pathway was induced by water stress in a C-3/CAM intermediate plant Sedum spectabile Boreau. Typical CAM criteria were observed upon 15 d of withholding water. Leaf delta(13)C value (-%) and water content showed a linear correlation fashion. Chlorophyll fluorescence parameters and antioxidative capacity were altered by water stress. Phi(PSII) and q(P) were reduced by 50% and 34% of the control, respectively, while NPQ rose ca. 180%. SOD activity and ability to scavenge DPPH. free radical went down but membrane permeability changed slightly. However, when an additional photooxidation by MV with high PPFD was carried out with leaf discs from watered (C-3 mode) and drought plants (CAM mode), q(P) and Phi(PSII) in leaves at induced CAM mode stage continuously decreased to a very low level. High 1 - q(P) value (0.86) and 1 - q(P)/NPQ ratio (>1) indicated the presence of high reduction state and unbalance of light energy budget. Together with the marked loss of membrane integral, it was evidenced that photooxidative damage was more serious in the induced CAM mode than in the C-3 mode. No advantage of photooxidation tolerance was found at the induced CAM expression stage of the facultative CAM plant, as compared with its C-3 mode stage, and also with the constitutive CAM plants reported previously. The differences in photooxidation sensitivity between the inducible CAM expressing plant and the constitutive CAM plant were discussed. 展开更多
关键词 Sedum spectabile facultative CAM plant photooxidation water stress CAM expression
下载PDF
Effects of seed aerosols on the growth of secondary organic aerosols from the photooxidation of toluene 被引量:14
5
作者 HAO Li-qing WANG Zhen-ya HUANG Ming-qiang FANG Li ZHANG Wei-jun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第6期704-708,共5页
Hydroxyl radical (.OH)-initiated photooxidation reaction of toluene was carried out in a self-made smog chamber. Four individual seed aerosols such as ammonium sulfate, ammonium nitrate, sodium silicate and calcium ... Hydroxyl radical (.OH)-initiated photooxidation reaction of toluene was carried out in a self-made smog chamber. Four individual seed aerosols such as ammonium sulfate, ammonium nitrate, sodium silicate and calcium chloride, were introduced into the chamber to assess their influence on the growth of secondary organic aerosols (SOA). It was found that the low concentration of seed aerosols might lead to high concentration of SOA particles. Seed aerosols would promote rates of SOA formation at the start of the reaction and inhibit its formation rate with prolonging the reaction time. In the case of ca. 9000 pt/cm^3 seed aerosol load, the addition of sodium silicate induced a same effect on the SOA formation as ammonium nitrate. The influence of the four individual seed aerosols on the generation of SOA decreased in the order of calcium chloride〉sodium silicate and ammonium nitrate〉ammonium sulfate. 展开更多
关键词 TOLUENE photooxidation secondary organic aerosol seed aerosol
下载PDF
The Relationship Among Photoinhibition, Photooxidation and Early Aging at a Late Development Stage in Different Varieties with High Yield 被引量:4
6
作者 JIAO De-mao, LI Xia, HUANG Xue-qing and JI Ben-hua( Institute of Agrobiological Genetics and Physiology, Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , P.R. China Department of Biology, Nantong Normal College, Nantong 226007 , P.R. China) 《Agricultural Sciences in China》 CAS CSCD 2002年第6期618-625,共8页
Using six high yield varieties from different ecological districts in China the parameters of Chl fluorescence, the performance of membrane lipid peroxidation and the reduction of Chl content in flag leaf under natura... Using six high yield varieties from different ecological districts in China the parameters of Chl fluorescence, the performance of membrane lipid peroxidation and the reduction of Chl content in flag leaf under natural condition at the later developmental stages (from heading stage to mature stage). The results showed that Fv/Fm , decreased gradually, the excessive light energy led to the accumulation of active oxygen O2-, H2O2 and the product of membrane-lipid peroxidation, MDA, which resulted in the reduction of Chl content and early aging due to photooxidation during the course of senescence of flag leaf. This phenomenon varied obviously in rice varieties. When comparina japonica tolerant to photooxidation, Fv/Fm in indica shanyou 63 susceptible to photoxidation decreased significantly. An increase of active oxygen and a sharp drop of Chl content, resulted in 'yellowish' early aging and influenced filling and setting of rice grain. The mechanism on early aging in indica was related to light and temperature conditions in filling stages. On a fine day (above 251), PS Ⅱ reaction center exhibited a dynamic change on revisable inactivation. Under strong midday light, PS Ⅱ function in indica exhibited obvious down-regulation and photoinhibition; Under strong light with low temperature, PS Ⅱ resulted in photodamage, showing early aging, which were related to the degradation of PSⅡ - D1 Protein and the inhibition of the endogenous protecting system such as Xanthophyll cycle and the enzymes of scavenging active oxygen. The results suggested that for a view of high-yield breeding, on the basis of a good type-plant, giving consideration to the utilization of heterosis and resistance to early aging, selecting japonica or a sterile line with japonice genotype as maternal was a breeding strategy worthy of being paid more attention. 展开更多
关键词 Rice Characteristics of chl fluorescence PHOTOINHIBITION photooxidation Early aging
下载PDF
Photooxidation of hydrochlorofluocarbons and hydrofluorocarbons initiated by OH radicals 被引量:2
7
作者 Zhong Jinxian Mu Yujing Yang Wenxiang(Research Center for Eco-Environmental Sciences Chinese Academy of Sciences, Beijing 100085, China)Chen Dazhou(Chinese Center for Certified Reference Materials, Beijing 100013, China) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1996年第2期228-234,共7页
Under simulated atmospheric condition, photoomdation for HCFC-22 + H2O2, HCFC-22 + H2O2+O2, HFC-134A + H2O2 and HFC-134A + H2O2+ O2 systems were studied.H2O2 was irradiated by low pressure mercury lamp and produced OH... Under simulated atmospheric condition, photoomdation for HCFC-22 + H2O2, HCFC-22 + H2O2+O2, HFC-134A + H2O2 and HFC-134A + H2O2+ O2 systems were studied.H2O2 was irradiated by low pressure mercury lamp and produced OH radicals. The OH radicals can initiate photooxidation of HCFC-22 and 134A. The products of photooxidation were determined by a Fourier Transform infrared Spectroscopy with a 20ml long path cell. The products were COF2,CO2, HCI, H2O and HF for HCFC-22 + H2O2 system, HO, CO2, HCI and HF for HCFC-22 +H2O2 +O2 system, HCOF, CF3OOCF3,CO2, H2O and HF for HFC-134A +H2O2 system, HCOF, CO2, H2O, and HF for HFC-134A + H2O2+ O2 system. Based on those results, the mechanisms of photooxidation were suggested. 展开更多
关键词 HYDROCHLOROFLUOROCARBONS HYDROFLUOROCARBONS photooxidation OH radicals FTIR.
下载PDF
Photooxidation of Furfural with Phthalocyanine-sensitized TiO_2 Particle Under Xenon Lamp 被引量:2
8
作者 KANG Chun-li LU Yu +3 位作者 GUO Ping ZHANG Fan YU Hong-bing LIN Xue-yu 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2007年第2期154-158,共5页
Copper phthalocyanine was selected as the photosensitizer to sensitize TiO2 in this experiment with furfural as the target pollutant. The composite catalysts(TiO2/CuPC) obtained showed a great activity under a xenon... Copper phthalocyanine was selected as the photosensitizer to sensitize TiO2 in this experiment with furfural as the target pollutant. The composite catalysts(TiO2/CuPC) obtained showed a great activity under a xenon lamp. By experiments, the optimal preparation conditions of the composite catalysts were set as follows : the CuPC loading mass fraction was 1.5%, the mass fraction of acetylacetone was 0. 3% , and the stirring time was 10 h. UV-Vis diffuse reflectance spectra, XRD, and BET were used to characterize the properties of the composite catalysts, which showed that after loading CuPC on TiO2, the composite catalyst retained the same crystal structure as pure TiO2 and the wavelength range of its absorption spectrum was broadened to 600-700 nm while its surface area was smaller than that of the pure TiO2. Under the optimal conditions, 20 mg/L furfural solution was degraded by nearly 90% and TOC by about 70%. When the catalyst was reused 6 times, the activity of the catalyst was still retained by about 75%. 展开更多
关键词 TiO2 CUPC Phthalocyanine-photosensitizer FURFURAL photooxidation
下载PDF
Characterization of products from photooxidation of toluene 被引量:2
9
作者 HAO Li-qing WANG Zhen-ya +4 位作者 FANG Li ZHANG Wei-jun WANG Wei LI Cheng-xiang SHENG Liu-si 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第5期903-909,共7页
Photooxidation reaction of toluene in smog chamber systems was initiated by the UV radiation of tolucne/CH5ONO/NOx mixtures. The products of the photooxidation reaction of toluene and its subsequent reactions were ana... Photooxidation reaction of toluene in smog chamber systems was initiated by the UV radiation of tolucne/CH5ONO/NOx mixtures. The products of the photooxidation reaction of toluene and its subsequent reactions were analyzed directly utilizing Fourier transform infrared spectrometer (FTIR). Detailed assignments to FTIR spectrum of gas-phase products were given. The information of some important functional groups in the products, such as, carbonyl groups (C-O), hydroxyl groups (-OH), carboxylic acid (- COOH), C-C bonding, N O bonding and C-H bonding (C H), was got from this analysis. These results were compared to those analyzed by aerosol time of flight mass spectrometer (ATOFMS). It was found that there are some differcnccs between FTIR analysis of gas-phase products and that of particle-phase, for example, the products with carbonyl groups, which were connected to unsaturated chemical bonds, was relatively higher in the gas phase, while kctoncs, aldehydes, carboxylic acid and organonitrates were the dominant functional groups in the aerosol-phase reaction products. The possible reaction pathways of some important products in the gas phase were also discussed. 展开更多
关键词 TOLUENE photooxidation secondary organic aerosol Fourier transform infrared spectrometer smog chamber
下载PDF
The Effects of Accelerated Photooxidation on Molecular Weight and Thermal and Mechanical Properties of PHBV/Cloisite 30B Bionanocomposites 被引量:1
10
作者 Kahina Iggui Mustapha Kaci +1 位作者 Nicolas Le Moigne Anne Bergeret 《Journal of Renewable Materials》 SCIE 2018年第3期288-298,共11页
The effects of accelerated photooxidation on the molecular weight and thermal and mechanical properties of Cast PHBV and PHBV/Cloisite 30B(3 wt%)bionanocomposites are investigated herein.Through size exclusion chromat... The effects of accelerated photooxidation on the molecular weight and thermal and mechanical properties of Cast PHBV and PHBV/Cloisite 30B(3 wt%)bionanocomposites are investigated herein.Through size exclusion chromatography(SEC)analysis,a significant decrease in both weight and number average molecular weights was observed for all irradiated samples over time,resulting from the chain scission mechanism.Differential scanning calorimetry(DSC)data indicated a decrease in degree of crystallinity and melting temperature after UV exposure,with the appearance of double melting peaks related to the changes in the crystal structure of PHBV.Thermal stability,tensile and thermo-mechanical properties were also reduced consecutively in photooxidation,being more pronounced for Cast PHBV.This study shows that the incorporation of Cloisite 30B in PHBV provides a better resistance to photooxidation in comparison with the neat polymer. 展开更多
关键词 Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) organo-modified montmorillonite BIONANOCOMPOSITES accelerated photooxidation and degradation
下载PDF
Kinetic Characteristic of Photooxidation of Cypermethrin by Organic Peroxy Radical
11
作者 Bi Gang Chen Chang-yang +3 位作者 Niu Fei Gu Ying-hong Tian Shi-zhong Cheng Jie-ke 《Wuhan University Journal of Natural Sciences》 EI CAS 2001年第3期725-728,共4页
The kinetic characteristic of photolysis of cypermethrin (CPM) sensitized by acetophenone (AP) and the effect of probe substance 2,6-Di-tert-butyl-4-methylphenol and tetralin is studied in this report. It showed that ... The kinetic characteristic of photolysis of cypermethrin (CPM) sensitized by acetophenone (AP) and the effect of probe substance 2,6-Di-tert-butyl-4-methylphenol and tetralin is studied in this report. It showed that the photolysis rate of CPM increases slightly with the increase of AP concentration; photolysis rate of CPM has no relationship with [CPM] itself; The more dipolar moment the solvent has, the more the interaction between radical and solvent has, and the slower the photolysis of CPM is. The addition of radical probe substance confirms that ROO·is more than RO·. The steady-state concentration of ROO·is about 10?8 mol·L?1. 展开更多
关键词 photooxidation CYPERMETHRIN organic peroxy SENSITIZATION
下载PDF
EFFECT OF PHOTOOXIDATION ON PHOTOLUMINESCENCE OF N, N'-DIPHENYL-N, N'-DI(M-TOLYL)-BENZIDINE AND RUBRENE CODOPED PMMA THIN FILMS
12
作者 YB. Hou, L.J. Meng and M.P. dos Santos ( Department of Physics, Minho University, Braga 4719, Portugal) ( Departamento de Fisica, Instituto Superior de Engenharia do Porto, Rua de Sao Tome, 4200 Porto, Portugal) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2001年第6期441-447,共7页
In this paper, the PMMA films doped with N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine and rubrene were fabricated by spin coating, and the effect of photooxidation on the photoluminescence of the doped PMMA thin f... In this paper, the PMMA films doped with N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine and rubrene were fabricated by spin coating, and the effect of photooxidation on the photoluminescence of the doped PMMA thin films was investigated. The results showed that under the irradiation of 350nm UV light, N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine can sensitized rubrene and results in the enhancement in the photooxidation of rubrene. The effect of photooxidation on the photoluminescence from rubrene was more obvious. Both lifetime measurement and in situ measurement of photoluminescence showed that rubrene molecules exist in two chemical surroundings. 展开更多
关键词 PHOTOLUMINESCENCE photooxidation
下载PDF
Study on the Direct Photooxidation of Near-Infrared Absorbing Benzothiazolone Cyanine Dye
13
作者 Li, J Chen, P +2 位作者 Zheng, DS Okasaki, T Hayami, M 《Chinese Chemical Letters》 SCIE CAS CSCD 1998年第1期107-110,共4页
In this paper, direct photooxidation of benzothiazolone cyanine dye: in acetonitrile was studied. The photoproducts had been identified by (HNMR)-H-1 and fast atom bombardment (FAB) mass spectrometry. The results show... In this paper, direct photooxidation of benzothiazolone cyanine dye: in acetonitrile was studied. The photoproducts had been identified by (HNMR)-H-1 and fast atom bombardment (FAB) mass spectrometry. The results showed that the N-ethylbenzothiazolone (I), the ionic acid (II), and ionic aldehyde (III) are the principal photoproducts. 展开更多
关键词 cyanine dyes photooxidation photoproduct FAB-MS
全文增补中
一种天然蓝色素可降解膜的制备及其油脂抗氧化性研究
14
作者 罗海澜 马翠云 +6 位作者 杜利月 张福华 李新伟 陈旭东 赵梦梦 陈树兴 王飞 《食品安全质量检测学报》 CAS 2024年第1期206-215,共10页
目的将真菌Pseudofusicoccum violaceum F10产的天然蓝色素添加到明胶基膜中制备成可降解抗氧化性膜,并探究该膜的抗氧化性能。方法将天然蓝色素按一定比例添加到明胶、羧甲基纤维素钠(sodium carboxymethylcellulose,CMC)、甘油制备的... 目的将真菌Pseudofusicoccum violaceum F10产的天然蓝色素添加到明胶基膜中制备成可降解抗氧化性膜,并探究该膜的抗氧化性能。方法将天然蓝色素按一定比例添加到明胶、羧甲基纤维素钠(sodium carboxymethylcellulose,CMC)、甘油制备的基础膜液中,制备成蓝色素膜;采用响应面优化成膜工艺;对膜的色素保留率、机械性能、透水性、抗氧化活性及抗油脂光氧化性等进行测定。结果色素添加浓度在0.02%~0.04%时,色素在膜中分布均匀,浓度增加到0.08%时,色素分布不均匀、有聚集现象;随着蓝色素添加量增大,膜的抗拉力强度增强,伸长率有所下降;最佳的成膜工艺是明胶2.474 g、CMC 1.125 g、甘油1.158 g、蓝色素0.03%;正常光照下膜的色素保留率可达90%以上,加速光照下膜的色素保留率可维持在80%以上;蓝色膜的自由基清除率随色素添加量的增加而增强,当添加量为0.06%时,1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基和2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)ammonium salt,ABTS]阳离子自由基的清除率分别为42.3%和32.4%;与无色素膜相比,蓝色素膜能使橄榄油的过氧化值(peroxide value,POV)降低45.7%。结论该蓝色膜有较好色素保留率、机械性能,同时具备抗氧化活性和抗光氧化性,本研究可为开发同时具备减缓油脂自动氧化和光氧化的可降解包装膜奠定了理论基础。 展开更多
关键词 Pseudofusicoccum violaceum F10 天然蓝色素 响应面试验 抗氧化活性 抗光氧化
下载PDF
ZnONP/g-C_(3)N_(4)柱撑结构复合材料构建及NO光氧化脱除研究
15
作者 张博川 许磊 +3 位作者 谢诚 孙永芬 叶千钧 刘燕芝 《工程科学学报》 EI CSCD 北大核心 2024年第11期2046-2054,共9页
随着现代工业的飞速发展,如何实现氮氧化物的有效脱除成为目前亟待解决的重要难题.本研究提出了一种在石墨相氮化碳(g-C_(3)N_(4))表面原位生长纳米氧化锌点阵构建柱撑结构复合材料策略,以实现在可见光下光氧化去除NO.通过离子吸附反应... 随着现代工业的飞速发展,如何实现氮氧化物的有效脱除成为目前亟待解决的重要难题.本研究提出了一种在石墨相氮化碳(g-C_(3)N_(4))表面原位生长纳米氧化锌点阵构建柱撑结构复合材料策略,以实现在可见光下光氧化去除NO.通过离子吸附反应,成功制备了不同氧化锌颗粒负载量的ZnO NP/g-C_(3)N_(4)柱撑结构复合光氧化剂,并对其结构和电子特性进行了研究.结果表明,氧化锌纳米颗粒(ZnO NP)的引入改善了g-C_(3)N_(4)的团聚,提高了比表面积,暴露出更多活性位点.异质结构的构建改善了复合材料能带结构,促进了光生载流子的迁移及分离,光氧化性能显著提升.在可见光照射下质量分数为2.5%的ZnO NP/g-C_(3)N_(4)样品展现出了优异的光氧化性能,对NO体积分数为3×10^(-5)%以下的混合空气光氧化去除表现出优良的高效稳定性.本研究为高性能光氧化剂的设计与构建提供了有效策略,并为消除工业NO污染物提供了技术参考. 展开更多
关键词 g-C_(3)N_(4) ZNO 纳米材料 光氧化 NO脱除
下载PDF
Z型全氟聚醚的合成及应用研究进展
16
作者 张文 刘波 +2 位作者 张鸣 杨旭仓 钟志刚 《有机氟工业》 CAS 2024年第2期17-22,共6页
对四氟乙烯光氧化反应、过氧基团的去除和端基处理合成Z型全氟聚醚的过程进行了系统论述,并深入分析了光氧化反应机理。按照Z型全氟聚醚端基类型的差异,分别介绍了带惰性端基和功能性端基Z型全氟聚醚的应用进展,分析了现有合成工艺存在... 对四氟乙烯光氧化反应、过氧基团的去除和端基处理合成Z型全氟聚醚的过程进行了系统论述,并深入分析了光氧化反应机理。按照Z型全氟聚醚端基类型的差异,分别介绍了带惰性端基和功能性端基Z型全氟聚醚的应用进展,分析了现有合成工艺存在的问题及解决方法,以期为Z型全氟聚醚的合成及应用研究提供有益参考。 展开更多
关键词 Z型全氟聚醚 光氧化反应 过氧化物 端基氟化
下载PDF
TiO_(2)-TDI粒子改性聚氨酯胶粘剂的市场性价比研究
17
作者 杨桂玲 潘凯 《粘接》 CAS 2024年第3期7-10,共4页
采用TiO_(2)粒子和二氧化钛-甲苯二异氰酸酯(TiO_(2)-TDI)粒子对聚氨酯胶粘剂进行了改性处理,研究了不同添加量的改性粒子对聚氨酯胶粘剂硬度、羟基指数、拉伸剪切强度和表面形貌的影响。结果表明,改性聚氨酯胶粘剂的邵氏硬度随着二氧... 采用TiO_(2)粒子和二氧化钛-甲苯二异氰酸酯(TiO_(2)-TDI)粒子对聚氨酯胶粘剂进行了改性处理,研究了不同添加量的改性粒子对聚氨酯胶粘剂硬度、羟基指数、拉伸剪切强度和表面形貌的影响。结果表明,改性聚氨酯胶粘剂的邵氏硬度随着二氧化钛粒子添加量的增加而逐渐增大,而老化1000 h后,改性聚氨酯胶粘剂的邵氏硬度会随着TiO_(2)粒子添加量的增加而逐渐减小。随着老化时间从0增加至1000 h,聚氨酯胶粘剂和改性聚氨酯胶粘剂的羟基指数(CI)都会随着老化时间的延长而逐渐增大,且相同老化时间下,PU+0.4%TiO_(2)-TDI的CI指数更小、拉伸剪切强度最大,其次为0.4%TiO_(2)改性聚氨酯胶粘剂。 展开更多
关键词 双循环经济 聚氨酯胶粘剂 改性 老化 抗光氧化
下载PDF
Effects of NO_(2) and SO_(2) on the secondary organic aerosol formation fromβ-pinene photooxidation
18
作者 Xiangyu Zang Zhaoyan Zhang +6 位作者 Yingqi Zhao Gang Li Hua Xie Weiqing Zhang Guorong Wu Xueming Yang Ling Jiang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第2期151-160,共10页
Elucidating the effects of anthropogenic pollutants on the photooxidation of biogenic volatile organic compounds is crucial to understanding the fundamental mechanisms of secondary organic aerosol(SOA)formation.Here,t... Elucidating the effects of anthropogenic pollutants on the photooxidation of biogenic volatile organic compounds is crucial to understanding the fundamental mechanisms of secondary organic aerosol(SOA)formation.Here,the impacts of NO_(2)and SO_(2)on SOA formation from the photooxidation of a representative monoterpene,β-pinene,were investigated by a number of laboratory studies.The results indicated NO_(2)enhanced the SOA mass concentrations and particle number concentrations under both low and highβ-pinene conditions.This could be rationalized that the increased O_(3)concentrations upon the NO_(x)photolysis was helpful for the generation of more amounts of O_(3)-oxidized products,which accelerated the SOA nucleation and growth.Combing with NO_(2),the promotion of the SOA yield by SO_(2)was mainly reflected in the increase of mass concentration,which might be due to the elimination of the newly formed particles by the initially formed particles.The observed low oxidation degree of SOA might be attributed to the fast growth of SOA,resulting in the uptake of less oxygenated gas-phase species onto the particle phase.The present findings have important implications for SOA formation affected by anthropogenic–biogenic interactions in the ambient atmosphere. 展开更多
关键词 Secondary organic aerosol Volatile organic compound Anthropogenic pollutant BETA-PINENE photooxidation
原文传递
“Steric Armor”Strategy of Blue Fluorescent Emitters against Photooxidation-Induced Degradation
19
作者 Sha-Sha Wang Jing-Rui Zhang +8 位作者 Kuan-De Wang Hao-Ran Li Peng-Hui Meng Yang Zhou Xiang Yu Ying Wei Quan-You Feng Yu-He Kan Ling-Hai Xie 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2024年第11期1223-1229,共7页
Stability against oxygen is an important factor affecting the performance of organic semiconductor devices.Improving photooxidation stability can prolong the service life of the device and maintain the mechanical and ... Stability against oxygen is an important factor affecting the performance of organic semiconductor devices.Improving photooxidation stability can prolong the service life of the device and maintain the mechanical and photoelectric properties of the device.Generally,various encapsulation methods from molecular structure to macroscopic device level are used to improve photooxidation stability.Here,we adopted a crystallization strategy to allow 14H-spiro[dibenzo[c,h]acridine-7,9′-fluorene](SFDBA)to pack tightly to resist fluorescence decay caused by oxidation.In this case,the inert group of SFDBA acts as a“steric armor”,protecting the photosensitive group from being attacked by oxygen.Therefore,compared with the fluorescence quenching of SFDBA powder under 2 h of sunlight,SFDBA crystal can maintain its fluorescence emission for more than 8 h under the same conditions.Furthermore,the photoluminescence quantum yields(PLQYs)of the crystalline film is 327%higher than that of the amorphous film.It shows that the crystallization strategy is an effective method to resist oxidation. 展开更多
关键词 Organic semiconductor photooxidation Spirocyclic aromatic hydrocarbons Crystal engineering Fluorescence
原文传递
非富勒烯受体有机太阳能电池稳定性研究进展
20
作者 郭雅雯 李大伟 +1 位作者 高杨 李翠红 《物理化学学报》 SCIE CAS CSCD 北大核心 2024年第6期15-19,共5页
近年来,基于非富勒烯受体(NFAs)的有机太阳能电池(OSCs)取得了迅猛的发展。单异质结OSCs的光电转换效率(PCE)已突破19%,这进一步推动了有机光伏技术的商业化进程。光电转换效率的快速提升源于活性层材料的创新开发、器件工程的优化以及... 近年来,基于非富勒烯受体(NFAs)的有机太阳能电池(OSCs)取得了迅猛的发展。单异质结OSCs的光电转换效率(PCE)已突破19%,这进一步推动了有机光伏技术的商业化进程。光电转换效率的快速提升源于活性层材料的创新开发、器件工程的优化以及对器件物理的更深刻理解。然而,稳定性问题已成为制约其商业化的一个主要因素。目前,关于活性层材料和电池器件稳定性的研究仍相对有限。在本综述中,我们对NFA-OSCs不稳定性的机理进行了简要介绍,包括NFAs的光氧化降解、不稳定的共混薄膜形貌以及界面层诱导的NFAs不稳定性。同时,我们总结了近年来国内外关于提高NFA-OSCs稳定性的研究策略。期望本综述能为实现高效、稳定的NFA-OSCs提供有益的指导。 展开更多
关键词 有机太阳能电池 非富勒烯受体 内部不稳定性 光氧化降解 形貌不稳定性 界面层
下载PDF
上一页 1 2 19 下一页 到第
使用帮助 返回顶部