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One color resonant two photon ionization spectroscopy of p-methylstyrene and theoretical calculation
Huang J Xiao D Bi W Xu X Gao Z Zhu Q Zhang C 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,66(2):371-376
The band origin of the S1<--S0 transition of p-methylstyrene is determined to be 34,276 cm-1 by one color resonant two photon ionization (1C-R2PI) method, which is red shifted by 3811 cm-1 with respect to that of benzene. This indicates that the interaction of the methyl and vinyl groups with the ring in the S1 state is greater than that in the S0 state. The active vibrations assigned from the R2PI spectrum are found to be the in-plane ring modes. The bands at 399, 613, 724, and 786 cm-1 are assigned to the vibrations 9b, 6b, 12, and 1, respectively, and discussed in detail. The experimental results are well supported by ab initio and density functional theory (DFT) calculations. 相似文献
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Huang J Tzeng W 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,67(3-4):824-829
One-color (1C), two-color (2C) resonant two-photon ionization (R2PI), and mass analyzed threshold ionization (MATI) methods have been applied to study the S(1)<--S(0) transition and threshold ionization of p-methylanisole. The excitation energy of the S(1)<--S(0) transition is determined to be 35,401+/-2 cm(-1), the adiabatic ionization energy of this molecule is measured to be 63,965+/-15 and 63,972+/-5 cm(-1) by the 2C-R2PI and MATI methods. Most of the observed R2PI and MATI bands result from the in-plane ring vibrations. The frequencies of vibrations 9b, 1 and 7a are measured to be 393, 800 and 1168 cm(-1) in the S(1) state, and 412, 811 and 1220 cm(-1) in the D(0) state, respectively. This indicates the molecular structure in the D(0) state is more rigid than that in the S(1) state. 相似文献
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Huang J Lin JL Tzeng WB 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,67(3-4):989-994
We have applied two-color resonant two-photon mass-analyzed threshold ionization technique to record the vibrational spectra of the selected rotamers of m-cresol. The adiabatic ionization energies of cis and trans m-cresol are determined to be 66,933+/-5 and 67,084+/-5 cm(-1), respectively. Frequencies of the in-plane ring vibrations 6a, 1, and 9b are measured to be 528, 720, 1167 cm(-1) for the cis and 520, 698, and 1153 cm(-1) for the trans m-cresol cation. This indicates that different orientation of the OH group with respect to the CH(3) group slightly influences these ring vibrations. 相似文献
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目的分析广东省惠州地区12岁以下儿童全血常见微量元素分布情况,了解该地区儿童不同发育时期微量元素含量的变化规律,为指导合理膳食和用药提供依据。方法对2014年1月—6月来惠州市第一人民医院儿科门诊及体检中心进行检查的499例12岁以下儿童,采用原子吸收光谱仪进行全血5种元素(Cu、Zn、Ca、Mg、Fe)及Pb元素进行检测,并进行统计分析。结果499例中表现为以钙和锌缺乏为主,分别占19.8%和18.6%,其次为铁(15.8%),全血铜、镁含量基本正常,铅在各组中均可检测到一定的阳性率。锌与铁元素缺乏存在一定的相关性。结论惠州地区1~12岁儿童微量元素缺乏比例较高且各元素缺乏情况在不同年龄段有统计学差异。结果提示家长应正确合理膳食,均衡营养,维持各元素间的平衡,并在儿童生长发育期定期进行微量元素检测,及早发现问题并进行治疗。 相似文献
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HUANG Jiangou XU Mancai ** LI Haitao SHI Zuoqing HE Binglin College of Chemistry Chemical Engineering Hunan Normal University Changsha The State Key Laboratory of Functional Polymer Materials for Adsorption Separation Institute of Polymer Chemistry Nankai University Tianjin 《Chinese Journal of Reactive Polymers》2002,(2)
1. INTRODUCTION Adsorption capacity and selectivity are improved when some ion exchange groups or hydrogen bonding acceptor or/and donors are introduced into common polymeric adsorbents [1~5]. R. F. Shi et al have synthesized a series of bifunctional ads… 相似文献
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Three polymeric adsorbents with hydrogen bonding acceptors, methylamine,N-methyl-acetamide and aminotri(hydroxymethyl)methane modified resins are synthesized fromchloromethylated X-5 resin. Adsorption isotherms of phenol and theophylline onto the three modifiedresins and the original X-5 resin from aqueous solution are measured. The results show thatadsorption of compounds with hydrogen bonding donor onto methylamine and N-methylacetamidemodified resins is enhanced as compared with that onto X-5 resin, and adsorption mechanismbetween the adsorbents and the adsorbates is mainly based on hydrogen bonding and hydrophobicinteraction. While adsorption of compounds with hydrogen bonding donor ontoaminotri(hydroxymethyl)methane modified resin is lowered as compared with that onto X-5 resin, andadsorption mechanism between the adsorbent and the adsorbates is mainly based on hydrophobicinteraction. 相似文献
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