期刊文献+
共找到136篇文章
< 1 2 7 >
每页显示 20 50 100
Tuning the Oxygen Anionic Redox Reversibility in Na_(0.67)Mn_(0.8)Fe_(0.1)Co_(0.1)O_(2)Through Sn Doping
1
作者 Huibo Wang Ling Li +4 位作者 Wenze Han Hao Guo Ivan ABobrikov Yujun Chai Xiangfeng Liu 《Renewables》 2023年第2期253-265,共13页
Oxygen anion redox chemistry in layered oxide cathodes for sodium-ion batteries has attracted great interest.However,the release of lattice oxygen caused by the irreversible anionic redox and Jahn–Teller effect accel... Oxygen anion redox chemistry in layered oxide cathodes for sodium-ion batteries has attracted great interest.However,the release of lattice oxygen caused by the irreversible anionic redox and Jahn–Teller effect accelerates the structural distortion and electrochemical degradation.Herein,we rationally construct a stable crystal lattice to enhance the reactivity and reversibility of oxygen redox and inhibit the Jahn–Teller effect by Sn doping.The stronger binding energy of Sn–O enhances the structural stability of the cathode,which is favorable to suppress the oxygen release and Jahn–Teller effect.Thus,the reversibility of oxygen redox and the stability of the layered structure are enhanced.The expansion of the interlayer spacing decreases the energy barriers for Na+ion intercalation,improving the rate performance of the electrode.Benefitting from the rational design,the electrode delivers an enhanced rate performance and cycling stability.This work offers some insights into tuning the oxygen anion redox chemistry as well as suppressing the Jahn–Teller effect by lattice modulation. 展开更多
关键词 sodium-ion batteries layered oxides cathode oxygen anion redox Jahn–Teller effect Sn substitution
原文传递
In situ generation of oxyanions-decorated cobalt(nickel)oxyhydroxide catalyst with high corrosion resistance for stable and efficient seawater oxidation
2
作者 Fengting Luo Pei Yu +2 位作者 Jueting Xiang Junjie Jiang Shijian Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期508-516,共9页
The development of efficient and robust anode materials for stable alkaline seawater electrolysis is severely limited by chlorine evolution reaction and chloride corrosion.Here,the sulfur-doped cobalt-nickel bimetalli... The development of efficient and robust anode materials for stable alkaline seawater electrolysis is severely limited by chlorine evolution reaction and chloride corrosion.Here,the sulfur-doped cobalt-nickel bimetallic phosphides(CoNiPS)are specifically designed as a pre-catalyst for navigating a surface reconstruction to fabricate the anions(PO^(3-)_(4) and SO^(2-)_(4))-decorated Co(Ni)OOH catalyst(R-CoNiPS)with exceptional durability and high activity for stable alkaline seawater oxidation(ASO).Various experiment techniques together with theoretical simulations both demonstrate that the in situ-generated PO^(3-)_(4) and SO^(2-)_(4) anions on catalyst surface can improve the oxygen evolution reaction(OER)activity,regulating and stabilizing the catalytic active species Co(Ni)OOH,as well as make a critical role in inhibiting the adsorp-tion of chloride ions and extending the service life of electrode.Therefore,this R-CoNiPS electrode exhi-bits superb OER activity toward AsO and stands out among the non-precious ASO electrocatalysts reported recently,requiring low overpotentials of 420 and 440 mV to attain large current densities of 500 and 1000 mA cm^(-2) in an alkaline natural seawater electrolyte,respectively.Particularly,the catalyst displays a negligible chloride corrosion at room temperature during ASO operation(>200 h)at 500 mA cm^(-2).This work opens up a new viewpoint for designing high-activity and durable electrocata-lystsforseawaterelectrolysis. 展开更多
关键词 Seawater electrolysis anions oxygen evolution reaction Chloride corrosion
下载PDF
A High Sensitivity Detection Method of Singlet Oxygen and Superoxide Anion 被引量:2
3
作者 MinHAO DaXING QunCHEN JuanWANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第6期679-682,共4页
This paper, for the first time, reports a method that can be used as a highly sensitive probe for singlet oxygen (1O2) and superoxide anion (O2-) in vitro or in vivo. FCLA(3,7-dihydro-6-{4-[2-(N'-(5-fluoresceinyl)... This paper, for the first time, reports a method that can be used as a highly sensitive probe for singlet oxygen (1O2) and superoxide anion (O2-) in vitro or in vivo. FCLA(3,7-dihydro-6-{4-[2-(N'-(5-fluoresceinyl)thioureido)ethoxy]phenyl}-2-methylimidazo{1,2-a}pyrazin-3-one sodium salt), a chemiluminescence (CL) analysis reagent, has been reported to sensitively react with 1O2 and O2- to emit photons with a spectral peak of 525nm. In this work, when human serum albumin (HSA) was added into FCLA solution to enhance the CL intensity, approximately 20 times, compared to that without HSA. The enhanced CL had the same 525 nm spectral peak, identical to that without HSA. By gradually reducing the molecular oxygen content in the solution, we find that the auto-oxidation of oxygen molecules dissolved in the solution plays an important role in the CL process. Based on these experimental evidences, we propose a novel and highly sensitive detection method of 1O2 and O2-, which may have a great potential in chemical and medical applications. 展开更多
关键词 Singlet oxygen superoxide anion chemiluminescence.
下载PDF
Inactivation of Bacillus Subtilis by Atomic Oxygen Radical Anion
4
作者 李龙春 王莲 +2 位作者 于宙 吕选忠 李全新 《Plasma Science and Technology》 SCIE EI CAS CSCD 2007年第1期119-124,共6页
UAtomic oxygen radical anion (O-) is one of the most active oxygen species, and has extremely high oxidation ability toward small-molecules of hydrocarbons. However, to our knowledge, little is known about the effec... UAtomic oxygen radical anion (O-) is one of the most active oxygen species, and has extremely high oxidation ability toward small-molecules of hydrocarbons. However, to our knowledge, little is known about the effects of O- on cells of micro-organisms. This work showed that O- could quickly react with the Bacillus subtilis cells and seriously damage the cell walls a s well as their other contents, leading to a fast and irreversible inactivation. SEM micrographs revealed that the cell structures were dramatically destroyed by their exposure to O-. The inactivation efficiencies of B. subtilis depend on the O- intensity, the initial population of cells and the treatment temperature, but not on the pH in the range of our investigation. For a cell concentration of 10^6 cfu/ml, the number of survived cells dropped from 10^6 cfu/ml to 10^3 cfu/ml after about five-minute irradiation by an O- flux in an intensity of 233 nA/cm^2 under a dry argon environment (30 ℃, 1 atm, exposed size: 1.8 cm^2). The inactivation mechanism of micro-organisms induced by O- is also discussed. 展开更多
关键词 atomic oxygen radical anion INACTIVATION Bacillus subtilis cell structure SEM
下载PDF
基于对苯二甲酸的MOFs对含氧阴离子的吸附及光降解研究
5
作者 陈悦 李田甜 +3 位作者 种仙娥 池立欣 钱俊峰 张致慧 《化工新型材料》 CAS CSCD 北大核心 2024年第7期273-278,共6页
以对苯二甲酸为配体与金属盐反应得到两个金属-有机框架材料Cd-MOF和UiO-66,通过X射线粉末衍射仪(XRD)、热分析仪(TG)以及氮气吸脱附对两种MOFs材料进行表征,测试材料的纯度、热稳定性以及多孔性。用所合成的材料进行吸附和光催化降解... 以对苯二甲酸为配体与金属盐反应得到两个金属-有机框架材料Cd-MOF和UiO-66,通过X射线粉末衍射仪(XRD)、热分析仪(TG)以及氮气吸脱附对两种MOFs材料进行表征,测试材料的纯度、热稳定性以及多孔性。用所合成的材料进行吸附和光催化降解含氧阴离子实验。结果表明:Cd-MOF对MnO^(-)_(4)、Cr_(2)O_(7)^(2-)和CrO_(4)^(2-)的吸附率分别可以达到100%、57%、62%,经过光降解后的去除率可达到100%、84%、87%,UiO-66对MnO^(-)_(4)、Cr_(2)O_(7)^(2-)、CrO_(4)^(2-)的吸附率分别可以达到66%、25%、60%,经过光降解后的去除率可达到99%、40%、87%。相对于吸附能力,两种MOFs材料对含氧阴离子尤其是含Cr阴离子均表现出更好的光催化降解能力,Cd-MOF对含氧阴离子的去除率优于UiO-66。机理研究表明,在光催化降解过程中产生了活性物质·O^(-)_(2)和·OH,它们的产生有助于提高降解效率。 展开更多
关键词 金属-有机框架材料 含氧阴离子 吸附 光催化降解 对苯二甲酸配体
原文传递
Exploring negative ion behaviors and their influence on properties of DC magnetron sputtered ITO films under varied power and pressure conditions
6
作者 Maoyang Li Chaochao Mo +6 位作者 Peiyu Ji Xiaoman Zhang Jiali Chen Lanjian Zhuge Xuemei Wu Haiyun Tan Tianyuan Huang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期442-449,共8页
We deposited indium-tin-oxide(ITO)films on silicon and quartz substrates by magnetron sputtering technology in pure argon.Using electrostatic quadrupole plasma diagnostic technology,we investigate the effects of disch... We deposited indium-tin-oxide(ITO)films on silicon and quartz substrates by magnetron sputtering technology in pure argon.Using electrostatic quadrupole plasma diagnostic technology,we investigate the effects of discharge power and discharge pressure on the ion flux and energy distribution function of incidence on the substrate surface,with special attention to the production of high-energy negative oxygen ions,and elucidate the mechanism behind its production.At the same time,the structure and properties of ITO films are systematically characterized to understand the potential effects of high energy oxygen ions on the growth of ITO films.Combining with the kinetic property analysis of sputtering damage mechanism of transparent conductive oxide(TCO)thin films,this study provides valuable physical understanding of optimization of TCO thin film deposition process. 展开更多
关键词 magnetron sputtering ion energy ITO thin film high energy oxygen anion
原文传递
阴离子膜电解水非贵金属析氧催化剂研究进展
7
作者 赵清锐 冯英杰 +3 位作者 付晓玥 周越 刘东兵 李蔚 《石油化工》 CAS CSCD 北大核心 2024年第10期1491-1496,共6页
因兼具碱性电解水低成本及质子交换膜电解水技术高效等优势,阴离子膜电解水制氢被认为是最有前景的绿氢制备技术。目前针对阴离子膜电解水制氢技术的研究多集中在非贵金属催化剂或低贵金属催化剂上,从组成、特征、制备方法等方面介绍了... 因兼具碱性电解水低成本及质子交换膜电解水技术高效等优势,阴离子膜电解水制氢被认为是最有前景的绿氢制备技术。目前针对阴离子膜电解水制氢技术的研究多集中在非贵金属催化剂或低贵金属催化剂上,从组成、特征、制备方法等方面介绍了应用于阴离子膜电解水中的金属氧化物、金属硫化物/磷化物、合金、氢氧化物等析氧催化剂的研究进展,并对阴离子膜电解水制氢析氧催化剂的发展方向进行了展望。 展开更多
关键词 阴离子膜电解水 析氧反应 电催化剂 非贵金属
下载PDF
盐湖卤水体系硼的存在形态及其分布规律的研究进展 被引量:3
8
作者 赵鋆 周桓 《盐科学与化工》 CAS 2024年第1期1-7,共7页
硼酸盐具有多样性和复杂性,液相硼物种有多种形态,明确盐湖卤水体系硼物种的存在形态及其分布规律是近年来卤水化学与热力学研究的热点。文章对硼酸盐水溶液结构的研究方法,硼氧配阴离子的相互作用与化学平衡,硼物种转化机制,盐湖卤水... 硼酸盐具有多样性和复杂性,液相硼物种有多种形态,明确盐湖卤水体系硼物种的存在形态及其分布规律是近年来卤水化学与热力学研究的热点。文章对硼酸盐水溶液结构的研究方法,硼氧配阴离子的相互作用与化学平衡,硼物种转化机制,盐湖卤水体系硼物种分布与离子组成的关系等方面中盐湖卤水体系硼的存在形态及其分布规律的研究进展进行了汇总和讨论。 展开更多
关键词 硼酸盐水溶液 硼氧配阴离子 溶液结构 盐湖卤水 拉曼光谱
下载PDF
高性能Ir基阳极双催化层阴离子交换膜电解水
9
作者 尹燕 尹硕尧 +2 位作者 陈斌 冯英杰 张俊锋 《材料导报》 EI CAS CSCD 北大核心 2024年第6期1-7,共7页
设计高性能低Ir阳极催化层对阴离子交换膜电解水(AEMWE)商业化发展至关重要。本研究采用催化剂涂覆基底(CCS)方法,构建基于氧化铱(IrO_(2))和碳载铱(IrC)双催化层的阳极结构,提出了一种新型双Ir催化层并提高了AEMWE性能。研究表明,在IrC... 设计高性能低Ir阳极催化层对阴离子交换膜电解水(AEMWE)商业化发展至关重要。本研究采用催化剂涂覆基底(CCS)方法,构建基于氧化铱(IrO_(2))和碳载铱(IrC)双催化层的阳极结构,提出了一种新型双Ir催化层并提高了AEMWE性能。研究表明,在IrC-IrO_(2)(先喷涂碳载铱,后喷涂氧化铱)催化层中,IrC高度分散特性有利于提高催化层中Ir的利用率,优化了催化层内电子、氢氧根离子的传输。采用商业Pt/C催化剂作为阴极,IrC-IrO_(2)阳极双催化层组装成碱性膜电极,在1 mol/L KOH电解质条件下,2.0 V时IrC-IrO_(2)电极达到了2.31 A/cm^(2)的高电流密度,而且在低浓度电解质以及纯水中依旧保持较高的性能。本研究为碱性膜电解水技术高效催化层的设计提供了参考。 展开更多
关键词 阴离子交换膜电解水(AEMWE) 析氧反应(OER) 双催化层 Ir基催化剂
下载PDF
醚氧-烷基间隔三离子侧链型PBI碱性膜研究
10
作者 杨睿祯 陈婉婷 +3 位作者 王小舟 崔福军 贺高红 吴雪梅 《现代化工》 CAS CSCD 北大核心 2024年第3期97-102,109,共7页
基于侧链接枝改性合成了一系列具有醚氧-烷基-醚氧链段间隔分布的三阳离子侧链型聚苯并咪唑膜(oat-PBI-x)。侧链中两段柔性的含醚链段有助于亲水通道和氢键网络的形成,促进OH-快速传递,而己烷基间隔段可打破侧链全亲水属性,有效抑制膜... 基于侧链接枝改性合成了一系列具有醚氧-烷基-醚氧链段间隔分布的三阳离子侧链型聚苯并咪唑膜(oat-PBI-x)。侧链中两段柔性的含醚链段有助于亲水通道和氢键网络的形成,促进OH-快速传递,而己烷基间隔段可打破侧链全亲水属性,有效抑制膜过度溶胀。在IEC为1.40 mmol/g时膜的综合性能达到最佳。80℃时电导率为144.4 mS/cm,拉伸强度保持在21 MPa,在80℃、1 mol/L KOH溶液中浸泡900 h后电导率保留率为91.7%。将其应用于H_(2)/O_(2)燃料电池,可在1549 mA/cm^(2)的高电流密度下达到611 mW/cm^(2)的峰值功率密度。 展开更多
关键词 阴离子交换膜 聚苯并咪唑 多阳离子侧链 醚氧键 燃料电池
原文传递
Determination of photochemically-generated reactive oxygen species in natural water 被引量:2
11
作者 ZHAN Manjun Nanjing Research Institute of Environmental Protection,Nanjing 210013,China. 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第3期303-306,共4页
Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environment. ROS may participate in the indirect photolysis of trace organic pollutants,... Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environment. ROS may participate in the indirect photolysis of trace organic pollutants, therefore resulting in changes in their environmental fates and ecological risks in natural water systems. Bisphenol A (BPA), an endocrine-disrupting chemical, exits widely in natural waters. The photodegradation of BPA promoted by ROS (-OH, 1O2, HO2./O2^-), which were produced on the excitation of ubiquitous constituents (such as nitrate ion, humic substances and Fe(Ⅲ)-oxalate complexes) in natural water under simulated solar radiation was investigated. Both molecular probe method and electron spin resonance (ESR) test were used for the characterization of the generated ROS. It was found that .OH was photochemically produced in the presence of nitrate ions, humic substances and Fe(Ⅲ)-oxalate complexes and that 102 was produced with the presence of humic substances. The steady-state concentrations of .OH was 1.27×10^-14 mol/L in a nitrate solution, and the second-order rate constant of BPA with "OH was 1.01×10^10 L/(mol.s). 展开更多
关键词 reactive oxygen species Bisphenol A hydroxyl radicals singlet oxygen superoxide anion radical PHOTODEGRADATION
下载PDF
Core-branch Co Ni hydroxysulfides with versatilely regulated electronic and surface structures for superior oxygen evolution electrocatalysis 被引量:3
12
作者 Bin Wang Cheng Tang +3 位作者 Hao-Fan Wang Xiao Chen Rui Cao Qiang Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第11期8-14,共7页
To satisfy the rapid development of gas-involving electrocatalysis(O2, CO2, N2, etc.), nanostructured electrocatalysts with favorably regulated electronic structure and surface nanostructures are urgently required. He... To satisfy the rapid development of gas-involving electrocatalysis(O2, CO2, N2, etc.), nanostructured electrocatalysts with favorably regulated electronic structure and surface nanostructures are urgently required. Herein, we highlighted a core-branch hydroxysulfide as a significantly enhanced oxygen evolution reaction electrocatalyst. This hydroxysulfide was facilely fabricated via a versatile interfacial reaction in S2- inorganic solution at room temperature for a designed period. The moderative growth kinetics contributed to the growth of interconnected hydroxysulfide nanosheets with high-sulfur contents on the hydroxide precursor substrates, resulting in a hierarchical nanostructure with multifunctional modifications, including regulated electronic structure, rapid electron highway, excellent accessibility, and facilitated mass transfer. Such synthetic methodology can be generalized and facilely governed by regulating the temperature, concentration, duration, and solvent for targeted nanostructures. Contributed to the favorably regulated electronic structure and surface nanostructure, the as-obtained core-branch Co2NiS2.4(OH)1.2 sample exhibits superior OER performance, with a remarkably low overpotential(279 m V required for 10.0 m A c^m-2), a low Tafel slope(52 m V dec^-1), and a favorable long-term stability. This work not only presents a promising nanostructured hydroxysulfide for excellent OER electrocatalysis, but also shed fresh lights on the further rational development of efficient electrocatalysts. 展开更多
关键词 oxygen evolution REACTION Hydroxysulfides anion regulation INTERFACIAL REACTION Hierarchical structure
下载PDF
Selenocysteine antagonizes oxygen glucose deprivation-induced damage to hippocampal neurons 被引量:3
13
作者 Xian-Jun Wang Mei-Hong Wang +5 位作者 Xiao-Ting Fu Ya-Jun Hou Wang Chen Da-Chen Tian Su-Yun Bai Xiao-Yan Fu 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第8期1433-1439,共7页
Designing and/or searching for novel antioxidants against oxygen glucose effective strategy for the treatment of human isdlemic stroke. Selenium is deprivation (OGD)-induced oxidative damage represents an an essenti... Designing and/or searching for novel antioxidants against oxygen glucose effective strategy for the treatment of human isdlemic stroke. Selenium is deprivation (OGD)-induced oxidative damage represents an an essential trace dement, which is beneficial in the chemo- prevention and chemotherapy of cerebral ischemic stroke. The underlying mechanisms for its therapeutic effects, however, are not well documented. Selenocysteine (SeC) is a selenium-containing amino acid with neuroprotective potential. Studies have shown that SeC can reduce irradiation-induced DNA apoptosis by reducing DNA damage. In this study, the in vitro protective potential and mechanism of action of SeC against OGD-induced apoptosis and neurotoxicity were evaluated in HT22 mouse hippocampal neurons. We cultured HT22 cells in a glucose-free medium containing 2 mM Na2S402, which formed an OGD environment, for 90 minutes. Findings from MTT, flow cytometry and TUNEL staining showed obvious cytotoxicity and apoptosis in HT22 cells in the OGD condition. The activation of Caspa se-7 and Caspase-9 further revealed that OGD-induced apoptosis of HT22 cells was mainly achieved by triggering a mitochondrial-medi- ated pathway. Moreover, the OGD condition also induced serious DNA damage through the accumulation of reactive oxygen species and superoxide anions. However, SeC pre-treatment for 6 hours effectively inhibited OGD-induced cytotoxicity and apoptosis in HT22 cells by inhibiting reactive oxygen species-mediated oxidative damage. Our findings provide evidence that SeC has the potential to suppress OGD-induced oxidative damage and apoptosis in hippocampal neurons. 展开更多
关键词 SELENIUM SELENOCYSTEINE ischemic stroke oxygen glucose deprivation hippocampal neuron MITOCHONDRIA reaction oxygen species superoxide anion oxidative damage APOPTOSIS
下载PDF
天然虾青素清除超氧阴离子的抗氧化能力 被引量:8
14
作者 郑鑫鑫 黄青 《食品研究与开发》 CAS 北大核心 2023年第14期8-12,162,共6页
为研究天然虾青素对超氧阴离子的抗氧化作用,该研究对邻苯三酚自氧化法进行适当改进,在原有方法的基础上引入无水乙醇溶解虾青素,通过分析邻苯三酚自氧化产物在325 nm附近的吸收变化评价虾青素的抗氧化活性,并与典型的抗氧化剂β-胡萝... 为研究天然虾青素对超氧阴离子的抗氧化作用,该研究对邻苯三酚自氧化法进行适当改进,在原有方法的基础上引入无水乙醇溶解虾青素,通过分析邻苯三酚自氧化产物在325 nm附近的吸收变化评价虾青素的抗氧化活性,并与典型的抗氧化剂β-胡萝卜素、维生素C和α-生育酚进行超氧阴离子清除能力的比较。结果表明,虾青素的超氧阴离子清除能力与维生素C相近,明显高于β-胡萝卜素和α-生育酚。 展开更多
关键词 虾青素 抗氧化 超氧阴离子 活性氧 邻苯三酚自氧化
下载PDF
阴离子空位调控电解水制氢过渡金属基催化剂的研究进展 被引量:1
15
作者 马惠 宋利 +1 位作者 于彦龙 李雷 《化学试剂》 CAS 北大核心 2023年第8期17-24,共8页
以可再生电力为电源的电解水制氢是一种制备高纯氢气的可持续发展路径。其中,析氢反应(HER)电催化剂的性能仍需进一步提升。阴离子空位具有增加活性位点、提升电导率以及优化中间体物质吸附能的作用,已被广泛应用于提高HER电催化剂性能... 以可再生电力为电源的电解水制氢是一种制备高纯氢气的可持续发展路径。其中,析氢反应(HER)电催化剂的性能仍需进一步提升。阴离子空位具有增加活性位点、提升电导率以及优化中间体物质吸附能的作用,已被广泛应用于提高HER电催化剂性能。综述了近几年阴离子空位调控HER电催化剂的研究进展,以促进电解水制氢的进一步发展。重点分析了阴离子空位的制备与表征、阴离子空位对电解水析氢的影响与机制,并对阴离子空位工程提升电解水制氢催化剂性能研究的挑战进行分析与展望。 展开更多
关键词 电解水 析氢反应 阴离子空位 氧空位 硫空位 硒空位 磷空位 双空位
下载PDF
纳米氧化镁及其复合材料的抗菌性能研究 被引量:22
16
作者 李世涛 乔学亮 +2 位作者 陈建国 吴长乐 梅冰 《功能材料》 EI CAS CSCD 北大核心 2005年第11期1651-1654,1663,共5页
参考最近有关文献,认为抗菌材料已经成为传统材料与环境一体化的方向,作为新型陶瓷抗菌剂的纳米MgO系材料与其它抗菌剂相比,表现出独特的抗菌性和广泛的应用背景,对其研究已成为国外研究的新热点。本文总结了纳米MgO粉体的制备方法,分... 参考最近有关文献,认为抗菌材料已经成为传统材料与环境一体化的方向,作为新型陶瓷抗菌剂的纳米MgO系材料与其它抗菌剂相比,表现出独特的抗菌性和广泛的应用背景,对其研究已成为国外研究的新热点。本文总结了纳米MgO粉体的制备方法,分析了其抗菌机理,概述了其最新研究进展和复合制备技术,最后指出了存在的问题和研究方向。 展开更多
关键词 纳米氧化镁 抗菌 复合抗菌剂 吸附作用 氧离子O^2-
下载PDF
观光木叶片挥发油成分及其对超氧阴离子抑制与清除活性研究 被引量:12
17
作者 何开跃 李晓储 +3 位作者 张双全 樊英鑫 邱金芬 毕慧敏 《林业科学研究》 CSCD 北大核心 2007年第1期58-62,共5页
用有机溶剂萃取法从观光木(Tsoongiodendron odorum)叶片中分离出挥发油,经GC/MS/计算机进行成分分析和定量测定,并且测定了其对超氧阴离子抑制与清除活性。鉴定出38种化合物,主要成分为酯类(33.396%),萜类(18.313%),醇类(12.065%)和芳... 用有机溶剂萃取法从观光木(Tsoongiodendron odorum)叶片中分离出挥发油,经GC/MS/计算机进行成分分析和定量测定,并且测定了其对超氧阴离子抑制与清除活性。鉴定出38种化合物,主要成分为酯类(33.396%),萜类(18.313%),醇类(12.065%)和芳香族化合物(9.484%)。研究结果表明,观光木叶片挥发油有较强的抑制与清除超氧阴离子活性。挥发油在稀释100倍时,抑制超氧阴离子活性最大,超过了植酸和没食子酸丙酯。在稀释20倍时,总SOD(T-SOD)活性达495.10 U.mL-1,其中CuZn-SOD活性为338.50 U.mL-1,占T-SOD的68.36%,Mn-SOD活性为156.70 U.mL-1,占T-SOD的31.64%。本研究结果为进一步探讨观光木叶片挥发油的保健功能提供了科学依据。 展开更多
关键词 观光木 挥发油 化学成分 超氧阴离子 SOD
下载PDF
TiO_2电极中O^(2-)的形成及迁移过程研究 被引量:7
18
作者 李泽全 张娜 +2 位作者 白晨光 陈小亮 陶长元 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2010年第3期473-476,共4页
采用融盐电解法,在900℃熔盐CaCl2中以烧结TiO2为阴极,石墨棒为阳极制备金属钛。研究O2-在TiO2电极中的形成及其迁移过程。结果表明:实验高温促使TiO2结构中氧空位的形成及O2-产生;O2-通过氧空位从阴极内部迁移到表面,钛酸钙是电解过程... 采用融盐电解法,在900℃熔盐CaCl2中以烧结TiO2为阴极,石墨棒为阳极制备金属钛。研究O2-在TiO2电极中的形成及其迁移过程。结果表明:实验高温促使TiO2结构中氧空位的形成及O2-产生;O2-通过氧空位从阴极内部迁移到表面,钛酸钙是电解过程的必然中间产物,阴极表面生成的致密金属层钛阻碍O2-从阴极内部往表面的迁移。 展开更多
关键词 二氧化钛 氧负离子 钛酸钙
下载PDF
槲皮素自氧化作用影响其超氧阴离子自由基清除能力的研究 被引量:25
19
作者 俞梅兰 余燕影 曹树稳 《食品工业科技》 CAS CSCD 北大核心 2006年第3期75-78,共4页
通过比较槲皮素在不同介质中紫外吸收光谱变化,探讨槲皮素自氧化作用影响因素及可能机理,采用邻苯三酚自氧化法研究了槲皮素自氧化作用对其清除超氧阴离子自由基能力的影响。结果表明,在pH>8时,槲皮素醇溶液发生自氧化作用,且作用强... 通过比较槲皮素在不同介质中紫外吸收光谱变化,探讨槲皮素自氧化作用影响因素及可能机理,采用邻苯三酚自氧化法研究了槲皮素自氧化作用对其清除超氧阴离子自由基能力的影响。结果表明,在pH>8时,槲皮素醇溶液发生自氧化作用,且作用强度随着槲皮素浓度、pH和实验温度的增大而增强;金属离子Ca2+、Fe2+、Fe3+、Cu2+、Mg2+等对槲皮素自氧化作用有增强效应,使槲皮素清除超氧阴离子自由基能力减弱,甚至出现负抑制;Mn2+、Al3+、Zn2+等离子对槲皮素自氧化作用有抑制,其中,Mn2+、Zn2+可增强槲皮素清除超氧阴离子自由基能力,而Al3+则减弱其清除能力。 展开更多
关键词 槲皮素 自氧化 超氧阴离子自由基
原文传递
近红外吸收菁染料分子链结构对其光氧化稳定性能的影响 被引量:10
20
作者 李军 陈萍 +3 位作者 赵江 郑德水 冈崎庸树 速水正明 《感光科学与光化学》 CSCD 1997年第4期343-350,共8页
本文对具有不同分子链结构及不同链长,而母核结构分别为吲哚类及喹啉类的六种菁染料在溶液中的光氧化稳定性能进行了研究.结果表明菁染料的光褪色主要是由光氧化反应所致,当在分子链上引入不饱和环体结构时,可以使菁染料分子的光稳... 本文对具有不同分子链结构及不同链长,而母核结构分别为吲哚类及喹啉类的六种菁染料在溶液中的光氧化稳定性能进行了研究.结果表明菁染料的光褪色主要是由光氧化反应所致,当在分子链上引入不饱和环体结构时,可以使菁染料分子的光稳定性能增加;而随着分子链长的增加菁染料的光氧化稳定性能则明显下降.通过顺磁共振谱测定结果表明,在菁染料的自敏光氧化反应原初过程中,既存在单重态氧过程又存在超氧负离子过程. 展开更多
关键词 菁染料 光氧化 链结构 红外吸收 光化学
下载PDF
上一页 1 2 7 下一页 到第
使用帮助 返回顶部