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对COIL中碱性过氧化氢(BHP)溶液中的HO2^-浓度进行了理论计算和实验测量。得到了HO2^-浓度随不同浓度的KOH和H2O2以及不同比例(体积)配比的变化规律,并做了不同浓度HO2^-对氯的利用率和激光输出功率影响的实验,获得的结果对优化BHP的配制和优化实验参数有较大的意义。 相似文献
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靳玲侠 《原子与分子物理学报》2018,35(6)
采用CCSD(T)/cc-pVTZ//B3LYP/6-311++G(2df,2p)水平上对CH3CHOH + HO2和CH3CH2O + HO2反应体系的单、三重态反应机理进行了详细的理论研究.计算结果表明,CH3CHOH + HO2反应主要发生在单重态势能面上,其中四条通道均为快速自发过程;CH3CH2O + HO2反应在三重态势能面上的通道CH3CH2O + HO2 → 3IM11 → 3TS11 → P11 (CH3CH2OH + 3O2)为动力学和热力学的优势路径. 大气中CH3CHOH比CH3CH2O更容易稳定存在. 相似文献
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靳玲侠 《原子与分子物理学报》2019,36(6)
采用CCSD(T)/cc-pVTZ//B3LYP/6-311++G(2df,2p)水平上对CH3CHOH + HO2和CH3CH2O + HO2反应体系的单、三重态反应机理进行了详细的理论研究.计算结果表明,CH3CHOH + HO2反应主要发生在单重态势能面上,其中四条通道均为快速自发过程;CH3CH2O + HO2反应在三重态势能面上的通道CH3CH2O + HO2 → 3IM11 → 3TS11 → P11 (CH3CH2OH + 3O2)为动力学和热力学的优势路径. 大气中CH3CHOH比CH3CH2O更容易稳定存在. 相似文献
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采用频率为1.8MHz的超声波在固定式声化学反应器内研究了声化学降解腐植酸的自由基氧化历程。通过采用TA溶液作为OH自由基捕获剂,吡啶溶液作HO2自由基捕获剂,以及KI溶液的I2释放法分别确定出实验条件下反应溶液中OH自由基的浓度为10^-7M,HO2自由基浓度为10^-5M及H2O2浓度为10^-5M。在此基础上研究了均相与多相催化条件下声化学降解腐植酸溶液的TOC削减情况。发现CeO2和Cu2O催化作用下腐植酸的降解效率分别较均相条件下提高40%和20%。并就反应机理和反应动力学过程进行了描述。 相似文献
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OH自由基是大气中最重要的氧化剂,准确测量对流层OH自由基的浓度是厘清我国二次污染形成机理的关键.本文介绍了一种基于同步光解的OH自由基便携式标定方法,使用汞灯的185 nm线辐射处于层流状态下的具有一定水汽浓度的合成空气,光解HO2和O2定量产生确定浓度的OH, HO2自由基和O3.开展了臭氧浓度及廓线分布因子P和氧气吸收截面等影响因素的准确测量,降低该标定方法的不确定度.进一步构建便携式标定装置,建立应用于实际外场标定的OH自由基浓度快速获取方法.开展基于激光诱导荧光技术OH自由基(LIF-OH)探测系统的准确标定测试,准确产生3×10^8-2.8×10^9 cm^-3浓度的OH自由基, LIF-OH探测系统的荧光信号与自由基浓度具有非常好的相关性.在综合外场观测(STORM)的应用中该标定装置的不确定度为13.0%,具有良好的稳定性和准确性,可以用于复杂外场环境下LIF-OH系统的快速标定. 相似文献
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运用密度泛函的B3LYP方法及CBS-QB3方法对HO2NO2(过氧硝酸,PNA)与OH自由基的反应进行了理论研究. 结果表明, 在计算所得的势能面曲线上存在五个产物通道,分别为H2O+NO2+O2、HOOH+NO3、NO2+HO3H、HO2+HONO2和HO2+HOONO. 对这五个通道分别进行了详细的研究,其中最主要的反应通道为:PNA+OH!M1!TS1!H2O+NO2+O2. 采用了一个准平衡近似的方法并运用CBS-QB3基础上的能量计算得到了300K下此反应路径的速率常数值为1.13 £10-1 相似文献
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Moshe Kuznietz Tomoo YamamuraDexin Li Yoshinobu Shiokawa 《Journal of magnetism and magnetic materials》2008
Rather old preparation of the compounds ThCo2Ge2 and ThCo2Si2 and their magnetic study in the temperature range 100–570 K, published by Omejec and Ban [Z. Anorg. Allg. Chem. 380 (1971) 111], indicated that both compounds ordered ferrromagnetically below 100 K. In order to verify the old data, polycrystalline samples of ThCo2Ge2 and ThCo2Si2 have been prepared by arc melting and subsequent annealing, and studied by X-ray diffraction at room temperature (RT), by superconducting quantum interference device (SQUID)-magnetization and AC-susceptibility measurements at 2–320 K, and by dc-magnetization measurements in variable magnetic fields up to 120 kOe at 5, 80, and 283 K. The magnetic measurements confirm the ferromagnetic ordering in both compounds, but with totally different Curie temperatures: ≈120(20) K for ThCo2Ge2 and above 320 K for ThCo2Si2. The paramagnetic values of ThCo2Ge2 and the ordering of both compounds are discussed and compared with the old results of Omejec and Ban. 相似文献
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Natural radiative lifetimes have been measured for the 3s 2 ns 2 S 1/2 (n≦10) and 3s 2 nd 2 D 5/2,3/2 (n≦11) sequences of aluminum using pulsed laser excitation of an atomic beam. The investigated states were populated from the ground configuration using UV pulses of wavelength down to 210 nm produced by a Nd: YAG- or an excimer-pumped dye-laser system. TheS-state lifetimes increase regularily with increasing principal quantum number but this is not the case for theD sequence. 相似文献
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M. J. Jongerius Tj. Hollander C. Th. J. Alkemade 《Journal of Quantitative Spectroscopy & Radiative Transfer》1978,20(6):599-607
Fluorescence-excitation (wing) profiles of the Na-D doublet lines were measured over a wavelength range extending from 0.3 to 200 Å from the line center for the red D1 and blue D2 wings and from 0.3 to 3 Å for the red D2 and the blue D1 wings, respectively. The line profiles were determined with the aid of a tunable CW dye-laser as a background source by measuring the total fluorescence intensity observed on detuning the laser wavelength. The flames were premixed, laminar, shielded flames at 1 atm, with temperatures ranging from 1860 to 2270 K; N2 and Ar served as diluent gases. The line core and near-wing profiles (i.e. the region covering 0.3<Δλ<7 Å for the outer wings and 0.3<Δλ<3 Å for the inner ones) in all of the flames studied appeared to have the same frequency dependence, regardless of the nature and concentrations of the gases used. The blue D2-line profile followed an unexpected (-2.2) law, while the other three profiles obeyed the theoretically expected (-2) law (the dispersion profile function). The line profile in the Δλ range between the impact and quasistatic regions was found to depend on the main perturbers involved. We found that the far blue D2- and red D1-wings in the Ar-diluted H2/O2 flame obeyed the (-) and (-) laws, respectively, as predicted by the quasi-static theory for the Lennard-Jones interaction. For the N2-diluted C2H2/O2 and H2/O2 flames, we did not find these wing dependences in the Δλ range investigated. 相似文献
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V.N. Nguyen F. Tcheou J. Rossat-Mignod R. Ballestracci 《Solid State Communications》1983,45(2):209-213
Neutron diffraction studies and magnetic measurements on the compounds TbNi2Si2 (1), HoCo2Si2 (2) and TbCo2Si2 (3) revealed a collinear antiferromagnetic order below TN = 10 ± 1 K (1), TN = 13 ± 1 K (2) and TN = 30 ± 2 K (3) with the rare earths moments oriented along the c-axis [m0 = 8.8 ± 0.2 μB (1), m0 = 8.1 ± 0.2 μB (2), m0 = 8.8 ± 0.2 μB (3)] and the corresponding wavevector are . The magnetic structure of the compounds HoCo2Si2 and TbCo2Si2 consists of ferromagnetic layers perpendicular to the c-axis coupled antiferromagnetically (+?+?) while for TbNi2Si2 the ordering within (0 0 1) plane is antiferromagnetic and the planes (0 0 1) are indeed decoupled. 相似文献
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Different compositions in the Lu2Si2O7-Sc2Si2O7 system have been synthesized following the ceramic method. All XRD patterns are compatible with the thortveitite structure (β-RE2Si2O7 polymorph). Unit cell parameters change linearly with composition, which indicates a complete solid solubility of Sc2Si2O7 in Lu2Si2O7. 29Si MAS NMR spectra show a decrease of the 29Si chemical shift with increasing Sc content. A correlation reported in the literature to predict 29Si chemical shifts in silicates is applied here to obtain the theoretical variation in 29Si chemical shift values in the system Lu2Si2O7-Sc2Si2O7 and the results compare favourably with the values obtained experimentally. The FWHM values of the 29Si MAS NMR curves indicate a random distribution of Lu and Sc in the structure of the intermediate members. Finally, the IR study of the system confirms the solubility of Sc2Si2O7 in Lu2Si2O7, showing the splitting of several modes in the intermediate members and a linear shift of the frequency on going from one end-member to the other. 相似文献
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T.P. Smirnova L.V. Yakovkina V.V. Kaichev Song Jeong-Hwan 《Journal of Physics and Chemistry of Solids》2010,71(5):836-840
The physical and chemical properties of the HfO2/SiO2/Si stack have been analyzed using cross-section HR TEM, XPS, IR-spectroscopy and ellipsometry. HfO2 films were deposited by the MO CVD method using as precursors the tetrakis 2,2,6,6 tetramethyl-3,5 heptanedionate hafnium—Hf(dpm)4 and dicyclopentadienil-hafnium-bis-diethylamide—Сp2Hf(N(C2H5)2)2.The amorphous interface layer (IL) between HfO2 and silicon native oxide has been observed by the HRTEM method. The interface layer comprises hafnium silicate with a smooth varying of chemical composition through the IL thickness. The interface layer formation occurs both during HfO2 synthesis, and at the annealing of the HfO2/SiO2/Si stack. It was concluded from the XPS, and the IR-spectroscopy that the hafnium silicate formation occurs via a solid-state reaction at the HfO2/SiO2 interface, and its chemical structure depends on the thickness of the SiO2 underlayer. 相似文献
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Experimental study on the system of Cl/Cl_2/He/HN_3/I_2 总被引:2,自引:0,他引:2
Using a microwave generator, chlorine diluted by helium was dissociated to chlorine atoms that subsequently reacted with hydrogen azide to produce the excited states of NCl(a1△). Meanwhile, molecular iodine with carrier gas of helium reacted with atomic chlorine to produce atomic iodine which then was pumped to excited state of I(2P1/2) by an energy transfer reaction from NCl(a1△). In this paper, the changes of NCl(a1△) and NCl(b1∑) emission intensity is presented when I2/He is introduced into the stream of Cl/Cl2/He/HN3/NCl(a1△)/NCl(b1∑). The dependences of atomic iodine I(2P1/2) on flow rates of gases were also investigated. The optimum parameters for I(2P1/2) production are given. 相似文献