检索结果-南通市图书馆

rempi/MATI Spectra and Theoretical Calculations of 2-Methoxypyridine and 2-(N-methylamino)pyridine:The Conformational Effect

在线全文

学校读者我要写书评

暂无评论

REMPI/MATI Spectra and Theoretical Calculations of 2-Methoxy...

298～330nm范围SF_2自由基(2+1)rempi光谱研究

第十五届全国化学动力学会议

作者：代文帅 Sheng Liu Min Cheng Yikui Du Qihe Zhu Beijing National laboratory of molecular Science State Key laboratory of Molecular Reaction DynamicsInstitute of ChemistryChinese Academy of Sciences University of Chinese Academy of Sciences

The vibrational spectra of 2-methoxypyridine(2 MOP) and 2-(N-methylamino)pyridine(2 NMP) in the first electronically excited(S) and cationic ground(D) states are obtained by-resonance-enhanced multi-photon ionization(rempi) and mass-analyzed threshold ionization(MATI) *** experimental results reveal that there are cis and trans conformers in the S,S,and D states of 2 ***,only cis conformer can be detected for the 2 MOP as predicted by the relaxed potential energy *** adiabatic ionization energies of 2 MOP,cis 2 NMP and trans 2 NMP are measured to be 69379,62518 and 62709 cm with an uncertainty of about 5 *** 2 MOP and trans 2 NMP,more prominent low-frequency peaks in the rempi spectrum of cis 2 NMP are observed and most of them are due to the motions of methylamino,indicating remarkable geometrical changes at methylamino group between the S(or D) state and S state of cis 2 *** ab initio and density functional theory calculations are performed to predict the optimized geometries and vibrational frequencies of 2 MOP and the two 2 NMP *** is found that a geometrical distortion along τ(CH) mode has occurred distinctly during the electronic excitation of cis 2 NMP,*** almost staggered(s) methyl in the S state becomes an eclipsed(e)conformer in the S and D *** MATI spectra suggest that the molecular geometries of these conformers in the D state are similar to those in the S *** natural bond orbital(NBO) and electron density topology are also performed to explain the s/e conformational effect in different electronic states of cis 2 NMP.

关键词： 2-methoxypyridine 2-(N-methylamino)pyridine rempi MATI conformer

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

量子电子学报 1998年第5期15卷 441-446页

作者：束继年张群戴静华李全新中国科学技术大学化学物理系合肥230026

1990年Hudgens等人在文献［1］中报道了SF2自由基4P里德堡态（3＋1）rempi光谱中存在不正常的振动间隔，迄今这一现象尚未研究清楚．我们从实验中获得了298～330nm范围的SF2自由基4p里德堡态（2＋1）rempi光谱．通过对光谱数据的分析，... 详细信息

1990年Hudgens等人在文献［1］中报道了SF2自由基4P里德堡态（3＋1）rempi光谱中存在不正常的振动间隔，迄今这一现象尚未研究清楚．我们从实验中获得了298～330nm范围的SF2自由基4p里德堡态（2＋1）rempi光谱．通过对光谱数据的分析，我们试探性地将这段光谱归属于SF2自由基从基态分别到二个不同电子激发态的共振跃迁．标识结果表明，这种归属能较好地解释4P里德堡态不正常的振动间隔的现象．并得到了相应的分子常数．

关键词： SF2自由基 rempi 光谱电子激发态

利用rempi方法测量BaF高里德堡系列光谱

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 1995年第4期8卷 308-313页

作者：马辉李俭刘耀明陈瓞延清华大学物理系

我们建立了一套电热高温扩散束装置，并利用ＲＥＭＰＩ－ＴＯＦ方法获得了ＢａＦ分子ｕ＝１，１３．６≤ｎ＊≤５６各里德堡态能级结构。初步分析显示，ｎ＊＜２２各态能级结构仍具有ｓ－ｐ－ｄ－ｆｓｕｐｅｒｃｏｍｐｌｅｘ特征。

关键词：氟化钡里德堡态数据 rempi

CF_2Cl自由基5p Rydberg态的rempi研究

在线全文

学校读者我要写书评

暂无评论

自然科学进展（国家重点实验室通讯） 1999年第A12期9卷 1346-1350页

作者：李全新张群束继年徐海峰俞书勤陈从香马兴孝中国科学技术大学化学物理系合肥230026

用直流脉冲放电方法制备CF_2Cl自由基,结合rempi技术,研究了310～330nm波长范围内CF_2Cl自由基(2+1)rempi光谱。对CF_2Cl自由基5p Rydberg态的带源、振动能级结构进行了分析,初步得到了该Rydberg态两个被激活的振动模ω_3′(a_1)和ω_4... 详细信息

用直流脉冲放电方法制备CF_2Cl自由基,结合rempi技术,研究了310～330nm波长范围内CF_2Cl自由基(2+1)rempi光谱。对CF_2Cl自由基5p Rydberg态的带源、振动能级结构进行了分析,初步得到了该Rydberg态两个被激活的振动模ω_3′(a_1)和ω_4′(b_1)的振动频率,并估算了5p Rydberg态量子亏损值。

关键词： CF2CL 自由基氟利昂 Rydberg态 rempi 大气化学

激光偏振特性对丙酮和氧气多光子电离质谱信号的影响

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

原子与分子物理学报 2005年第3期22卷 568-572页

作者：张霞孔祥和樊新岩张树东王仍蔡廷栋曲阜师范大学物理工程学院曲阜273165

在极性分子丙酮复合物CH3COCH3·H2O和非极性分子氧气的rempi谱中,母体离子信号强度与激光偏振方向的关系是不同的。改变532nm激光偏振方向,记录了两种分子母体离子信号强度,实验结果表明,对于氧气分子的母体离子信号强度,激光偏振方向... 详细信息

在极性分子丙酮复合物CH3COCH3·H2O和非极性分子氧气的rempi谱中,母体离子信号强度与激光偏振方向的关系是不同的。改变532nm激光偏振方向,记录了两种分子母体离子信号强度,实验结果表明,对于氧气分子的母体离子信号强度,激光偏振方向的改变对其没有影响,而对于CH3COCH3·H2O的母体离子信号强度,随偶极矩与激光偏振方向夹角的增加,其母体离子信号强度呈余弦曲线变化,且与夹角余弦的2·1次幂成正比。理论分析显示,CH3COCH3·H2O的rempi母体离子信号强度应与此夹角的余弦的2次幂成正比。这就说明实验结果和理论分析是相符的。

关键词： rempi 母体离子极性分子偶极矩

Rapid analysis of trace pollutants using laser mass spectrometry

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2001年第7期44卷 940-946页

作者：魏杰章莲蒂顾学军张冰孔祥和郑海洋夏柱红 Laboratotry of Laser Spectroscopy Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei China

Organic pollution has been gaining more and more ***,at present the determination of virtually all of them,including polycyclic aromatic carbons (PAHs),the largest single class of chemical carcinogens known today,is made via pre-purification and *** major problems are complexity and time-consuming,thus,no ideal real-time on-line monitoring can be *** mass spectrometry combines UV spectroscopy and time-of-flight mass spectrometry (TOF-MS) through resonance-enhanced multiphoton ionization (rempi).It is characteristic of high sensitivity,high selectivity and *** this paper,after its principles,a small mobile laser mass spectrometer,in which a mini-excimer (KrF,248 nm) laser was used,is ***-time analysis of vehicle exhaust gas was made using this instrument,and the results showed some advantages over traditional methods:multicomponent detection,including benzene,toluene,xylene,C3-benzene,naphthalene,and methyl-naphthalene; high sensitivity (100 ppb);high time-resolution (0.1 s);and no need for pre-purification or pre-concentration of samples.

关键词：激光集体 spectrometry 污染物质察觉芳香的烃 rempi TOFMS

A multiphoton ionization study of acetone using time-of-flight mass spectrometry

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2010年第27期55卷 3123-3130页

作者： ZHENG XianFeng WU HongXia SONG Yu WU JingZe ZHANG JingSong CUI ZhiFeng Department of Physics Anhui Normal University Wuhu 241000 China Department of Chemistry University of California Riverside CA 92521 USA

The 3p Rydberg states of acetone and photodissociation of the acetone cation were studied using time-of-flight(TOF)mass *** 3p Rydberg state spectroscopy of acetone was investigated with linearly polarized two-photon resonance enhanced multiphoton ionization(rempi)from 320 to 337 *** new transition bands were observed in the *** addition to the CH3COCH3 + ion,CH3CO + and CH3 + fragments were *** laser power dependences suggest that the CH3COCH3 +,CH3CO + and CH3 + ions are produced in three-,four-,and four-photon processes,*** of CH3CO + and CH3 + involves excitation of the ground state acetone cation by an additional photon and subsequent decomposition of the excited acetone *** average translational energies of CH3CO + and CH3 + from dissociation in CH3COCH3 +(X)+hv→CH3CO + +CH3 and CH3COCH3 +(X)+hv→CH3 + +CH3CO,respectively,were derived from the ion TOF peak profiles.

关键词：共振增强多光子电离飞行时间飞行质谱丙酮阳离子 rempi CH3 线性偏振

Laser mass spectrometry for high sensitive and multi-component analysis of exhaust gas from vehicles

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2001年第1期46卷 86-88页

作者： Liandi Zhang Jie Wei Haiyang Zheng Ziyao Li Zhuhong Xia Xuejun Gu Bin Zhang Chinese Acad Sci Anhui Inst Opt & Fine Mech Lab Laser Spect Hefei 230031 Peoples R China

Laser mass spectrometry is a newly developed method for pollutant detection. It combines resonance-enhanced multiphoton ionization (rempi) and time-of-flight mass spectro- metry (TOF-MS). It may detect pollutants with high sensitivity, high selectivity and in a multi-component way. In this note, laser mass spectrometry was used to detect the pollutants in exhaust gases from vehicles. With one-color rempi (at 266 nm), several aromatic hydrocarbons, including benzene, toluene, xylene, C3-benzene, etc., were detected. These substances were selectively ionized by (1+1) rempi and their mass resolution was detected by a TOF mass spectrometer. And a quantitative analysis was achieved.

关键词： laser mass spectrometry rempi TOF-MS aromatics.

242—260nm波长区CS_2分子的多光子解离电离

在线全文

学校读者我要写书评

暂无评论

物理化学学报 1998年第11期14卷 1007-1012页

作者：张立敏陈军戴静华王储记章弢陈从香马兴孝中国科学院选键化学开放实验室合肥230026 中国科技大学化学物理系合肥230026

在242－260nm波氏范围通过CS2分子的共振增强多光子电离（rempi）获得了母体离子CS和碎片离子的分质量激发谱．在λ＜246.4nm区间，CS激发谱上呈现出来源于CS2双光子电离的弥散谱带,碎片离子激发谱的归属强烈提示多光子过程中有中性基... 详细信息

在242－260nm波氏范围通过CS2分子的共振增强多光子电离（rempi）获得了母体离子CS和碎片离子的分质量激发谱．在λ＜246.4nm区间，CS激发谱上呈现出来源于CS2双光子电离的弥散谱带,碎片离子激发谱的归属强烈提示多光子过程中有中性基电子态的CS和S（经由CS2的光解离）产生：（1）CS+的谱带主要来源于中性CS碎片经由单光子跃迁产生的（1＋1）共振增强电离，（2）除了部分S+的谱峰来自CS+的光解外，多数S+的锐谱峰来自中性S原子经由3p3（2D0）4p，3p3（4S0）np（n＝6，7，8）←3p43pJ（J＝2，1,0）双光子跃迁产生的（2＋1）共振增强电离．

关键词：多光子解离电离 CS碎片 S原子 rempi 二硫化碳