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1.
通过发射光谱对大气压氦等离子体射流三个不同位置进行测量, 并采用光谱拟合获得氮气分子振转温度的方法, 研究了放电电压和气体流量以及离喷口的距离对射流的温度和化学活性的影响。发现大气压等离子体射流的气体温度和振动温度均随着放电电压增加而升高, 随着气体流量的增大而降低, 随着离喷口距离的增加而降低并逐步趋于稳定。通过对等离子体射流中振动温度的变化趋势并结合活性成分氧原子光谱强度的变化证实了等离子体射流的活性亦随着气体流量及离喷口距离的增大而降低, 随着放电电压增加而升高的结论。  相似文献   

2.
利用显微拉曼对违禁药品麻黄素以及伪麻黄素———左旋咪唑致幻药物做了拉曼测试 ,在激发光 5 1 4 5nm和室温环境下 ,得到了麻黄素和左旋咪唑分子的拉曼散射谱。麻黄素属单取代苯类 ,具有Cy2ν对称性 ,我们对它的拉曼振动模式做了识别。并将麻黄素的拉曼谱和甲基安非他明做了对比分析 ,麻黄素和甲基安非他明同属单取代苯 ,其分子结构十分相似 ,由于取代基的成分不一样 ,因而拉曼谱中一些峰的相对强度和位置发生了变化  相似文献   

3.

The pressure response of Raman phonons, determined for several hcp metals, includes positive pressure shifts as well as anomalies like mode softening in connection with phase transitions. It is shown that the phonon frequencies and their pressure dependences are related to macroscopic elastic parameters. More general, these results show that the measurement of Raman-active phonons in metals provides a direct probe of bonding, and agreement with theoretical models gives additional confidence in ab initio techniques.  相似文献   

4.
This work is devoted to the determination of the vibrational population of hydrogen molecules in the ground and excited electronic states from the analysis of visible spectra of the H2 molecules excited by an RF discharge in an expanding thermal arc plasma. Comparison of the experimental results on relative electron-impact excitation cross sections for the transition H2(X1Σ, υ0 = 0)→ H2(d3IIu, υ′) with other experiments, and with calculations based on the Franck-Condon principle, shows good agreement. This means, that for plasma under investigation: 1) in the ground electronic state H2(d3IIu,υ′), only the lowest vibrational level with υ0 = 0 is significantly populated, and 2) direct electron exictation of H2(d3IIu, υ′, υ′) state from the ground state H2(X1Σ, υ0 = 0) dominates.  相似文献   

5.
分子振动光谱法与中药研究的最新进展   总被引:24,自引:8,他引:24  
本文叙述了分子振动光谱法(傅半叶变换拉曼光谱技术和傅立叶变换红外光谱技术)的量新发展与中药的无损定性鉴别、定量分析、热稳定性监控及中药优化的最新应用。报道了利用傅立叶变换拉曼光谱技术(FT-Raman)和漫反射傅立叶变换2红外光谱技术(DR-FTIR)可以直接快速地鉴别生药材;利用漫反射傅立叶变换近红外光谱技术(DR-NIR)可以无损定量分析中药材、中成药和方剂的组分含量利用FT-Raman和HA  相似文献   

6.
用高灵敏的光腔衰荡光谱(Cavity Ring-Down Spectroscopy)方法探测到了正丙醇波长在620和700nm附近的高激发泛频振动光谱,将其归属于分子不同稳定构象的O-H伸缩振动(ν=4、5)泛频吸收,谱带用高斯函数模拟后得到的每一个峰都对应于分子的一个或几个稳定构象。用局域模理论(Local Mode Theory)对同一分子的不同泛频振动(ν值不同)进行了分析指认,求出了分子羟  相似文献   

7.
A multi reference internally contracted configuration interaction (MRCI) method is used to generate the potential energy function (PEF) of the excited electronic state of HCN molecule. The analytic representation of the PEF is employed to calculate complex eigenvalues (resonance positions and widths) by a discrete variable representation (DVR) of the Hamiltonian for the non-rotating (J =0) molecule. The computational method used is a variant of the filter-diagonalization technique based on a recursive polynomial expansion of the absorbing-boundary-conditions (ABC) Green operator. Reasonable agreement with existing experimental data is found. Received 27 July 1999 and Received in final form 18 October 1999  相似文献   

8.
Abstract

The analytical applications of the evolved gas analysis (EGA) performed by infrared spectroscopy, for the period extending from 2005 to 2009, are collected in this review. By this technique, the nature of volatile products released by a substance subjected to a controlled temperature program are on-line determined, with the possibility to prove a supposed reaction, either under isothermal or under heating conditions.  相似文献   

9.
时间分辨红外发射光谱法对自由基反应的研究   总被引:2,自引:0,他引:2  
在过去的 15年中 ,傅立叶变换红外发射光谱法广泛应用于研究气相自由基反应 .Sloan首先研究了O(1D)的反应 ,随后Leone和Hancock研究了O(3 P)的反应 .此后 ,孔繁敖和朱起鹤等研究了小自由基 ,包括CH、CH2 、CH3 、C2 H3 、C2 H5、C2 H、C3 H3 和C3 H5与O2 、NO、N2 O、NO2 等分子的反应。在红外光谱中观察到各个反应的初生产物和初步反应通道 ,和从头算的理论研究结合起来 ,这些反应的机理已基本弄清 .  相似文献   

10.
Emission spectroscopy using electrical discharge, flame, and X-ray excitation has been the anlytical method of choice in the majority of a i r pollution studies involving trace metals analysis in particulate pollutants. The extensive literature in this area is reviewed here. The emphasis is on analytical methods rather than on specific results. Complete sections are devoted to review and survey literature, electrical discharge methods by element, flame excitation, and X-ray excitation. Wherever possible, information is included on sample preparation, standardization, excitation mode, detection method, and analytical results in terms of sensitivity, reproducibility, and area of application.  相似文献   

11.
原子发射光谱双谱线法测量固体火箭发动机内燃气温度   总被引:7,自引:0,他引:7  
发展了一种利用原子发射双谱线法,测试固体火箭发动机燃烧室内燃气温度的方法,设计了相应的测试系统。该方法利用石英光学纤维,将固体火箭发动机内高温高压燃气的光谱辐射信号传入测量系统;选用了两条波长间隔小的谱线,大大减少了光谱辐射率,光谱透射率等对光谱测量的影响,设计使用了耐压测量探头,保证在高压,强腐蚀条件下,系统的密封性和光的透过率,对装填有SQ-2推进剂的固体火箭发动机燃烧室内的气流温度进行了在线检测,测量时间分辨率可高达0.5μs。  相似文献   

12.
黄剑 《光谱实验室》2001,18(4):482-484
本文选择了合适条件,建立了纯钽中钇的原子发射光谱测定方法。  相似文献   

13.
在 76 4 0 0~ 796 5 0cm-1的能量范围内测量了三氯乙烯的真空紫外脉冲场电离 光电子 (VUV PFI PE)谱 .根据量子化学理论计算的频率以及Franck Condon因子 ,对VUV PFI PE谱的振动谱带进行了标定 ,确认了11个三氯乙烯阳离子的振动频率 ,分别为 :ν1+ =14 8cm-1,ν2 + =180cm-1,ν3 + =2 86cm-1,ν4+ =4 0 2cm-1,ν5+=4 72cm-1,ν6+ =6 6 0cm-1,ν7+ =875cm-1,ν8+ =990cm-1,ν9+ =10 38cm-1,ν10 + =12 6 7cm-1,ν11+ =14 0 8cm-1.这些测量和新近用真空紫外 红外光诱导电离确定的ν12 + =30 73cm-1一起 ,提供了三氯乙烯阳离子电子基态的所有 12个振动频率的实验值 .通过对VUV PFI PE谱 (0 ,0 )跃迁带的光谱拟合 ,确定了三氯乙烯的电离能为(76 4 4 1.7± 2 .0 )cm-1((9.4 776± 0 .0 0 0 2 )eV) .  相似文献   

14.
Two polymorphic forms (I and II) of 4-fluorophenylpyruvic acid (F-PPA) were obtained by crystallization from different solvents, showing a melting point at 163.2 and 171.0 °C. Crystal structures of polymorphs I and II were determined by X-ray crystallography. IR and Raman spectra of the two polymorphs were measured and the spectral characteristics were compared with those of phenylpyruvic acid. the two polymorphs show similar molecular and crystal structures to each other, except for the molecular geometries of the enol and the carboxylic acid moieties. Distinct IR spectral differences which result from the crystal field splitting were observed between the two polymorphs.  相似文献   

15.
The Fourier transform infrared and Fourier transform Raman spectra of xanthoxyline crystals are reported, along with ab initio computations of the vibrational spectrum of the xanthoxyline molecule. The infrared and Raman spectra were recorded at 300?K in the 400- to 4,000- and 40- to 4,000-cm?1 intervals, respectively. The vibrational wave numbers and wave vectors were obtained from a density functional computation with the 6-31 G(d,p) basis set and the B3LYP approximation to the exchange correlation functional. Comparison with the theoretical results allows assignment of normal modes to the prominent features of the recorded spectra.  相似文献   

16.
The rotational spectra of the unstable HCCCP molecule have been investigated in the millimeter-wave region for the main excited vibrational states which lie below 1000 cm(-1), namely nu(4) (C&bond;C stretch), nu(5) (HCC bend), nu(6) (CCC bend), nu(7) (CCP bend), 2nu(6), 2nu(7), 3nu(7), 4nu(7), nu(5) + nu(7), and nu(6) + nu(7). l-type resonance effects have been taken into account in the analysis of the spectra, so that the values of the anharmonicity constants x(L(66)), x(L(77)), x(L(57)), and x(L(67)) could be determined. The anharmonic interactions which couple the nu(4) state with nu(6) + nu(7), 2nu(6), and 4nu(7) have been also considered, yielding the unperturbed value of the alpha(4) vibration-rotation coupling constant. Copyright 2001 Academic Press.  相似文献   

17.
18.
本文在原子吸收光谱仪的发射方式上,选择钡553.5nm发射线,以空气乙炔火焰为发射光源,进行了火争发射法测钡的方法研究。全面讨论了测试条件和干扰试验,并与ICP-AES、笑气乙炔AAS,以及空气乙炔AAS进行了比较,还讨论了乙醇的增感作用,并对出口材料中的可溶性钡进行了测定比较,得到满意结果。  相似文献   

19.
叙述了用光电光谱法测定钢中酸溶硼的方法,探讨了影响结果稳定性和准确性的因素.用本法测定钢中酸溶硼,具有良好的准确度和精密度,结果令人满意.  相似文献   

20.
利用发射光谱研究脉冲电晕放电中的自由基   总被引:10,自引:2,他引:10  
利用发射光谱技术在大气压下测量了以氮气为载气的不饱和水蒸气体系针-板式正脉冲电晕放电产生的OH(A^2∑→X^2Ⅱ0—O)自由基和O(3p^5P→3s^5S^02777.4nm),Ha(3P→2S 656.3nm)活性原子的发射光谱,并由N2(C^3Ⅱu→B^3Ⅱg)的△v=-3和△v=-4振动带序发射光谱强度计算得出N2(C,v)的相对振动布居及其振动温度,进而采用高斯分布拟合准确地求出了N2(C^3Ⅱu→B^3Ⅱg)的△v= 1振动带序发射光谱强度,从而可以由N2(C^3Ⅱu→B^3Ⅱg)的△v= 1振动带序与OH(A^2∑→X^2Ⅱ0—0)的重叠发射光谱中准确求出OH(A^2∑→X^2Ⅱ0—0)自由基的发射光谱强度。由发射光谱强度得到了激发态OH(A^3∑)自由基和O(3p^5P),Ha(3P)活性原子的布居。还研究了激发态OH(A^2∑)自由基和O(3p^5P),Ha(3P)活性原子的布居随放电电压和放电频率的变化以及氧气对激发态OH(A^2∑)自由基和O(3p^5P),Ha(3P)活性原子布居的影响。  相似文献   

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