喹啉降解过程瞬态粒子的光谱分析

利用纳秒级脉冲辐解技术对喹啉在多种条件下降解过程中所生成的瞬态粒子行为进行了详细分析.探讨了喹啉在羟基、氢自由基、水合电子、SO4·-,Br2·-、叠氮化钠等作用下生成的瞬态粒子的吸收光谱、瞬态粒子的生成和衰减行为,可作为实际含喹啉废水溶液降解研究的理论参考.     

水溶液中金属团簇的脉冲辐解研究进展

介绍了以脉冲辐解技术为手段研究水溶液中单金属团簇的形成机理,并对团簇的性质及其反应进行了简要的概括,对今后团簇的发展趋势进行了展望。     

N2O饱和胞嘧啶水溶液体系辐解的瞬态产物研究

在确定胞嘧啶阴离子自由基特征吸收的基础上，采用脉冲辐解技术，以Ｎ２ＯＲ ｅ＾－ａｑ的清除剂对Ｃｙｔ水溶液进行了研究。实验结果显示：在不存在自由ｅ＾－ａｑ条件下仍产生了Ｃｙｔ的两个特征吸收峰，即位于λｍａｘ＝３３５±５ｍｍ处的Ｃｙｔ－吸收峰和其质子化产物的吸收峰。     

用脉冲辐解法研究尼古丁的化学活性

首次运用电子脉冲辐解技术研究尼古丁分子的化学活性。实验表明 ,在尼古丁分子中存在有多个活性点 ,它们可分别与水合电子、氢自由基、羟基自由基作用 ,生成不同的中间产物 ,得到不同的吸收峰 ,并测定了它们的生成反应速率常数。尼古丁分子易与水合电子、氢自由基、羟基自由基作用这些特性可以解释尼古丁分子所具有的一些生理活性 ,同时为尼古丁分子的改性工作提供理论基础。     

VP-16与DNA分子间电子转移的光谱学研究

运用脉冲辐解和圆二色谱技术,对用于治疗肿瘤的依托泊甙(VP-16)与鸟苷酸(GMP)和小牛胸腺DNA分子间电子转移的光谱进行了探讨.用脉冲辐解技术发现了VP-16与GMP之间的电子转移,测得两者之间的反应速率常数为3.16×107 L·mol-1·s-1,并对它们的吸收光谱进行了归属,同时用圆二色谱技术发现了VP-16与小牛胸腺DNA之间相互作用.从而为医学工作者进一步了解和探讨VP-16的抗肿瘤机理提供了直接的理论依据.     

脉冲辐射技术研究茶多酚类化合物的单电子还原电位

单电子还原电位是辐射保护和敏化中“电荷转移”的根本判据,采用时间分辨脉冲电子辐解瞬态吸收光谱装置,在ｐＨ＝７．０的磷酸缓冲溶液中,以杜醌（－２４４ｍＶ）为参比,准确地测定了茶多酚类化合物表儿茶素没食子酸酯（ＥＣＧ）、表没食子酸儿茶素（ＥＧＣ）、表儿茶素（ＥＣ）的单电子还原电位值Ｅ７＾１分别为－３２４、－３２０、－３２６ｍＶ;并通过与ＤＮＡ碱基胸腺嘧啶的单电子还原电位（－１１００ｍＶ）作比较,从热力     

离子强度对脉冲辐解法测定的单电子还原电位的影响

深入分析了采用脉冲辐解技术测定物质的单电子还原电位时是否考虑离子强度的影响问题，结论是：若选定的参比物本身不带电荷，则对所有的单电子还原电位还不必考虑溶液中离子强度的影响；若选定的参比物本身带电荷，则需考虑离子强度的影响；此外，还运动Ｍａｒｃｕｓ电子转移理论定性地讨论了影响电子转移反应速率的主要因素。     

三烷基氧化膦辐解产物的气相色谱研究

用高分辨率毛细管气相色谱法及等离子体光谱法研究了核工业领域应用的萃取剂三烷基氧化膦（ＴＲＰＯ）酸性含磷解产物。研究表明,在γ辐照条件下酸性辐解产物主要为二烷基膦酸、一烷基膦酸,磷酸及脂肪酸。其产额分别为０．５８、０．６７、０．０１４及０．５６。     

用脉冲辐解和激光光解技术研究C60和三氯乙烷的反应机理

用脉冲辐射和激光光解技术研究Ｃ６０－和ＣＨ３ＣＣｌ３的反应机理。发现Ｃ６０在６５０ｎｍ有循环吸收，认为在脉冲辐射实验中是通过空穴转移以及在激光光解实验中通过激发态转移两种不同的机制产生的。另外，在４３０ｎｍ处观察到Ｃ６０和ＣＨ３ＣＣｌ３的长寿命自由基加合物的产生，认为这个自由基加合物在脉冲辐解和激光光解过程中分别以自由基加成机制和通过形成激发态络合物现两种不同的机制产生的。     

γ辐照三烷基氧膦中烷烃的顶空气相色谱法测定

建立了顶空气相色谱法测定γ辐照三烷基氧膦中微量轻质烃的方法。研究了色谱条件及顶空加热条件。方法的回收率为 90 %— 10 9% ,对正戊烷、正己烷、正辛烷的检出限分别为 8.7× 10 - 7、3.2× 10 - 6 、3.1× 10 - 5g/ m L。用于测定三烷基氧膦中轻质烃辐解产物得到满意的结果     

吖啶橙与肝素钠相互作用的分光光度法研究

用分光光度法研究吖啶橙与肝素钠的结合反应,吖啶橙主要以静电作用的方式与肝素钠发生相互作用.在pH 2.0的Britton-Robinson(B-R)缓冲溶液中,吖啶橙在478和492 nm处有特征吸收峰,当加入肝素钠后,492 nm处的吸光度值强度降低且在453 nm处出现了一个新的吸收峰,说明两者之间发生了较强的相互作用形成了一种新的复合物,利用摩尔比法求解两者的结合比为1:3.在最佳条件下,吸光度值的降低与肝素钠的浓度在3.0～15.0 mg·L-1范围内呈良好的线性关系,表观摩尔吸光系数ε=1.599×105L·mol-1·cm-1,检测限(3σ)为0.236 mg·L-1.该方法简单、快速,应用于肝素钠注射液效价的测定,结果令人满意.     

Properties of carbon and iron modified TiO2 photocatalyst synthesized at low temperature and photodegradation of acid orange 7 under visible light

The nanoparticles of TiO₂ modified with carbon and iron were synthesized by sol-gel followed solvothermal method at low temperature. Its chemical composition and optical absorption were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence emission spectroscopy (PL), UV-vis absorption spectroscopy, and electron paramagnetic resonance (EPR). It was found that carbon and iron modification causes the absorption edge of TiO₂ to shift the visible light region. Fe(III) cation could be doped into the matrix of TiO₂, by which could hinder the recombination rate of excited electrons/holes. Superior photocatalytic activity of TiO₂ modified with carbon and iron was observed for the decomposition of acid orange 7 (AO7) under visible light irradiation. The synergistic effects of carbon and iron in modified TiO₂ nanoparticles were responsible for improving visible light photocatalytic activity.     

水溶性磷酸盐柱[5]芳烃与吖啶橙的络合行为

本文首先构建了水溶性磷酸盐柱[5]芳烃（PP5A）与阳离子荧光染料吖啶橙（AO）主-客体络合物.然后通过紫外光谱（UV）、红外吸收光谱（IR）、分子荧光光谱（MFS）、一维和二维核磁共振（NMR）波谱技术（包括¹H NMR和NOESY）研究了PP5A与AO的络合行为.此外，还研究了pH及两种表面活性剂——十二烷基硫酸钠（SDS）和十六烷基三甲基溴化铵（CTAB）对AO/PP5A络合体系的荧光强度的影响.最后，采用分子对接计算了PP5A与AO和CTAB的络合模式及络合能.研究表明，AO与PP5A形成1：1的主-客体络合物；在pH=3~11范围内，PP5A均能使AO的荧光强度发生减弱或淬灭；SDS和CTAB的加入并不会对AO/PP5A络合体系的荧光强度产生显著影响.AO与PP5A络合时产生的荧光强度变化可为荧光传感器的设计提供理论基础.     

Degradation of Acid Orange 7 in aqueous solution by zero-valent aluminum under ultrasonic irradiation

Degradation of azo dye Acid Orange 7 (AO7) by zero-valent aluminum (ZVAl) in combination with ultrasonic irradiation was investigated. The preliminary studies of optimal degradation methodology were conducted with sole ultrasonic, sole ZVAl/air system, ultrasonication + ZVAl/air system (US-ZVAl). In ZVAl/air system, the degradation of AO7 could almost not be observed within 30 min. The degradation of AO7 by ZVAl/air system was obviously enhanced under ultrasound irradiation, and the enhancement is mainly attributed to that the production of hydroxyl radicals in ultrasound-ZVAl process was much higher than that in sole ultrasonic or in sole ZVAl/air system. The variables considered for the effect of degradation were the power of ultrasound, the initial concentration of AO7, as well as the initial pH value and the dosage of zero-valent aluminum. The results showed that the decolorization rate increased with the increase of power density and the dosage of ZVAl, but decreased with the increase of initial pH value and initial concentration of AO7. More than 96% of AO7 removal was achieved within 30 min under optimum operational conditions (AO7: 20 mg/L, ZVAl: 2 g/L, pH: 2.5, ultrasound: 20 kHz, 300 W). This study demonstrates that ultrasound-ZVAl process can effectively decolorize the azo dye AO7 in wastewater.     

添加剂对AP/Al热分解影响的红外光谱与热分析研究

采用傅里叶变换红外吸收光谱(FTIR)和差示扫描量热法(DSC)研究了草酸铵(AO),碳酸锶(SC)及复配的草酸铵/碳酸锶等添加剂对复合固体推进剂主要组分高氯酸铵(AP)的作用机理。红外分析表明:草酸铵使AP各吸收峰消失的温度延后。碳酸锶在凝聚相中与AP的分解产物高氯酸发生反应生成比较稳定的产物高氯酸锶,IR光谱证实了高氯酸锶的存在。DSC分析结果表明:草酸铵的加入使AP高温阶段的分解放热峰向高温方向移动,但对AP低温阶段的分解放热峰没有影响。碳酸锶的加入使AP两个阶段的分解放热峰均向高温方向移动。草酸铵/碳酸锶的加入,虽然使AP的分解放热峰均向高温方向移动,但是实验发现,在常压下草酸铵/碳酸锶的组合配方没有发挥对AP高温分解的协同作用。基于上述实验探讨了草酸铵和碳酸锶抑制AP分解的作用机理。     

An undercutting model of atomic oxygen for multilayer silica/alumina films fabricated by plasma immersion implantation and deposition on polyimide

Multilayer silica/alumina films were created by plasma immersion implantation and deposition to protect against atomic oxygen (AO) in low earth orbit environment. The AO erosion mechanism of polyimide under multilayer silica/alumina films has been investigated using a ground-based AO simulator and Monte Carlo model. The results demonstrate that protective films are detached and plumped due to AO undercutting, and the exterior silica film is partly detached proven by chemical composition depth profile and erosion patterns. The undercutting model involving collision, diffusion, reaction, gas releasing, and retroaction on films is proposed. Based on the model, scattered impingement has serious erosion, although AO does not directly attack interior polymer. AO erosion predictions at two neighborhood cracks are first studied by Monte Carlo model for various incidence angles of AO. The protective film between cracks hinders the escape of AO, and accelerates the erosion.     

Excimer Emission of Acridine Orange Adsorbed on Gadolinium-Yttrium Orthovanadate Nanoparticles

Studying the complexes of inorganic nanoparticles – organic dye molecules is of great importance for their theranostics application. In this paper, we report gadolinium-yttrium orthovanadate nanoparticles (VNPs) – Acridine Orange (AO) complex formation in water solutions. To study the interactions between VNPs and AO, the methods of steady-state and time-resolved spectroscopy were used. It was shown that in aqueous solutions containing VNPs, AO aggregation takes place with a sandwich-like stacking of AO molecules in the near-surface layer of VNPs. The VNPs–AO complex formation causes significant changes in the AO fluorescence spectrum, namely, the appearance of a new broad, structureless band in the long-wavelength spectral edge, which was not observed in AO spectrum in a pure water solution. By analyzing of the absorption, fluorescence excitation spectra and fluorescence decay, the static excimer origin of the long-wavelength fluorescence band has been established.     

脉冲放电等离子体/活性炭联合体系中OH自由基的发射光谱研究

基于 OH 自由基的强氧化性(2.8 V)及脉冲放电等离子体(pulsed discharge plasma,PDP)与活性炭(activated carbon,AC)联合体系的协同作用,依托于光谱检测技术简单、准确性高、灵敏度高等优点,利用发射光谱技术测量了以 O2作为载气的PDP/AC联合体系中产生的 OH 自由基的相对发射光谱,用以表征体系中 OH 自由基相对生成量的变化。通过考察PDP 水处理体系中不同 AC 添加量、脉冲峰值电压、电极间距对OH 自由基相对发射光谱强度的影响,分析了影响OH 自由基生成量的因素;通过比较,分析去离子水和酸性橙 II(acid orange,AO7)溶液中 OH 自由基发射光谱强度的变化规律,表征了 OH 自由基生成量的变化,以说明PDP/AC的协同作用机理及OH 自由基对有机物的氧化作用。研究结果表明,增加AC的添加量可以增强其在PDP体系中的催化效果,导致 PDP/AC 联合体系中 OH 自由基的相对发射光谱强度的增加;随着脉冲峰值电压的升高,注入PDP体系中的能量增加,从而增加了体系中OH 自由基的产量;电极间距增加导致PDP体系能量效率降低,降低了OH 自由基的产生量;无论是以去离子水还是以AO7溶液为溶液相,PDP/AC联合体系中 OH 自由基的产量均高于其在单独PDP体系中的生成量,且在 PDP/AC联合体系和单独的PDP作用体系中,去离子水中 OH 自由基的相对发射光谱强度均高于其在 AO7溶液中的强度值,这证明了 AC对PDP体系中 OH 自由基生成的协同作用和有机物对 OH 自由基的消耗。     

Synthesis, characterization and application of iodine modified titanium dioxide in phototcatalytical reactions under visible light irradiation

Iodine doped titanium dioxide has been successfully prepared by simple hydrolysis of tetrabutyl titanate in the presence of iodic acid. The adopted method allowed for the production of spherical iodine doped titaniun dioxide nanoparticles with varied amount of iodine content. Analysis by X-ray diffraction, Raman, transmission electron microscopy as well as UV-vis DRS revealed that titanium dioxide nanostructures were doped with iodine which existed in two different valence states I⁵⁺ and I⁻. The iodine in the form of I⁵⁺ is believed to have doped into the lattice whereas I⁻ was well dispersed on the surface of TiO₂ probably as iodine adducts hence rendering it to be highly absorbing in visible light region. The I-TiO₂ exhibited improved photocatalytic activity toward degradation of acid orange 7 (AO7), methyl orange (MO) and 2,4-dichlorophenol (2,4-DCP) under visible light over the pristine TiO₂ prepared by the same method. High catalytic properties are attributed to iodine doping which led to high specific surface area, absorption in visible region as well as alleviation of charge carrier recombination. The most probable route undertaken in the degradation of AO7 is through indirect oxidation by the hydroxyl radicals.     

槲皮素与Cu2+和Al3+配位反应的紫外可见吸收光谱法研究

采用带有快门的增强型瞬态光谱探测系统ICCD, 实时拍摄了槲皮素与Cu2+ 和Al3+ 配位反应的紫外-可见吸收光谱。结果显示, Cu2+ 和Al3+与槲皮素配合, 在中性条件下都有吸收峰为428 nm左右的中间产物产生, 最终产物都在300 nm左右有稳定的吸收峰; 而酸性条件下则直接生成吸收峰为300 nm左右的最终产物。虽然Cu2+ 和Al3+是不同的金属离子, 但在相同的酸性或中性条件下, 它们与槲皮素的配合过程却是相似的,只是完成反应所需要的时间不同。本文结果为进一步研究槲皮素与金属离子配合的机理提供了实验依据。