The fluorescence/phosphorescence excitation spectra, the dispersed fluorescence/phosphorescence spectra and the sensitized phosphorescence excitation spectrum have been measured for jet-cooled p-benzoquinone. The assignments of vibronic bands in the 1B1g(n-,π∗) ← 1Ag and 1Au(n+,π∗) ← 1Ag transitions have been definitely established. The phosphorescence spectra from vibronic levels of 3Au exhibit a feature of single vibronic level emission. The 3Au ← 1Ag transition was also vibrationally analyzed.
{"title":"Singlet And Triplet n,π∗ Transitions of Jet-Cooled p-Benzoquinone","authors":"I. Suzuka, M. Sanekata, Mitsuo. Ito, N. Ohta","doi":"10.1155/1994/72592","DOIUrl":"https://doi.org/10.1155/1994/72592","url":null,"abstract":"The fluorescence/phosphorescence excitation spectra, the dispersed fluorescence/phosphorescence spectra \u0000and the sensitized phosphorescence excitation spectrum have been measured for jet-cooled p-benzoquinone. \u0000The assignments of vibronic bands in the 1B1g(n-,π∗) ← 1Ag and 1Au(n+,π∗) ← 1Ag transitions \u0000have been definitely established. The phosphorescence spectra from vibronic levels of 3Au exhibit a \u0000feature of single vibronic level emission. The 3Au ← 1Ag transition was also vibrationally analyzed.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129804625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The infrared multiphoton excitation of D2CO was studied by monitoring infrared fluorescence from stretching modes of D2CO following excitation in the bending modes. The dependence of the infrared multiphoton dissociation yield on laser wavelength, on laser power, and on reactant and foreign gas pressures was also studied. Severe bottlenecks to excitation through the first few steps are found. Vibration-to-vibration transfer of a bending quantum from one excited D2CO molecule to another is a crucial step. Collision-induced changes of rotational quantum number must also play an important role.
{"title":"The Small Molecule Limit of Infrared Multiphoton Dissociation: Collisional Effects in D2CO","authors":"M. Berman, C. Moore","doi":"10.1155/LC.8.169","DOIUrl":"https://doi.org/10.1155/LC.8.169","url":null,"abstract":"The infrared multiphoton excitation of D2CO was studied by monitoring infrared fluorescence from stretching modes of D2CO following excitation in the bending modes. The dependence of the infrared multiphoton dissociation yield on laser wavelength, on laser power, and on reactant and foreign gas pressures was also studied. Severe bottlenecks to excitation through the first few steps are found. Vibration-to-vibration transfer of a bending quantum from one excited D2CO molecule to another is a crucial step. \u0000Collision-induced changes of rotational quantum number must also play an important role.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128476537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Picosecond Spectroscopy of Photoreceptor Molecules","authors":"F. Aussenegg, M. Lippitsch, M. Riegler","doi":"10.1155/LC.6.269","DOIUrl":"https://doi.org/10.1155/LC.6.269","url":null,"abstract":"","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129303867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Preliminary results of the application of optical coherence tomography (OCT), in particular in its spectral mode (SOCT) to the control of a varnish ablation process, are presented. Examination of the ablation craters made with an Er:YAG laser allows optimization of the laser emission parameters controlling fluence with respect to efficiency and safety of the ablation process. Results of measurements of ablation crater depth as a function of the number of pulses for a given fluence are presented for selected resins. This validates the applicability of SOCT to calibration of ablation conditions for the particular laser-varnish-paint layer combinations, and of its usage in planning the varnish ablation procedure. These results also imply that a review of conventional ablation thresholds is called for. Applicability of the SOCT technique to contemporaneous in situ monitoring of the range of varnish ablation is discussed.
{"title":"Varnish Ablation Control by Optical Coherence Tomography","authors":"M. Gora, P. Targowski, A. Rycyk, J. Marczak","doi":"10.1155/2006/10647","DOIUrl":"https://doi.org/10.1155/2006/10647","url":null,"abstract":"Preliminary results of the application of optical coherence tomography (OCT), in particular in its spectral mode (SOCT) to the control of a varnish ablation process, are presented. Examination of the ablation craters made with an Er:YAG laser allows optimization of the laser emission parameters controlling fluence with respect to efficiency and safety of the ablation process. Results of measurements of ablation crater depth as a function of the number of pulses for a given fluence are presented for selected resins. This validates the applicability of SOCT to calibration of ablation conditions for the particular laser-varnish-paint layer combinations, and of its usage in planning the varnish ablation procedure. These results also imply that a review of conventional ablation thresholds is called for. Applicability of the SOCT technique to contemporaneous in situ monitoring of the range of varnish ablation is discussed.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129740817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Systematic behavior of decay rates of resonances above dissociation threshold is investigated by using the theory of resonance scattering. The condition for the Rice-Ramsperger-Kassel-Marcus (RRKM) rate formula to be valid is clarified by analyzing the random model of unimolecular dissociation. The decay rate averaged over many resonances agrees with the RRKM rate when the mean spacing and the mean width of the resonance states coincide with each other. On the other hand, auto- and mutual-correlation functions of the non-stationary wave functions indicate a rather paradoxical and intriguing phenomenon: In the RRKM regime, insufficient time is left for intramolecular vibrational energy redistribution (IVR) before dissociation.
{"title":"Competition Between Intramolecular Vibrational Energy Re-Distribution and Unimolecular Dissociation: A Scattering Theoretical Point of View","authors":"K. Someda, Hiroki Nakamura, F. Mies","doi":"10.1155/1995/59696","DOIUrl":"https://doi.org/10.1155/1995/59696","url":null,"abstract":"Systematic behavior of decay rates of resonances above dissociation threshold is investigated by using the theory of resonance scattering. The condition for the Rice-Ramsperger-Kassel-Marcus (RRKM) rate formula to be valid is clarified by analyzing the random model of unimolecular dissociation. The decay rate averaged over many resonances agrees with the RRKM rate when the mean spacing and the mean width of the resonance states coincide with each other. On the other hand, auto- and mutual-correlation functions of the non-stationary wave functions indicate a rather paradoxical and intriguing phenomenon: In the RRKM regime, insufficient time is left for intramolecular vibrational energy redistribution (IVR) before dissociation.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123517312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Changes in the pharmaceutical L-adrenaline-D-hydrogentartrate, incorporated in KBr matrices, induced by a pulsed carbon-dioxide Transversely Excited Atmospheric (TEA) laser, were observed. Modifications of the sample were monitored via infrared spectra. Special attention was devoted to the dependence of the sample changes on the laser energy density used. The irradiation of the pharmaceutical has been performed with two laser lines at wavelengths of about 10.6 µm. The laser lines coincide well with the absorption band of the pharmaceutical, which is assigned to the ring vibrations/out-of-plane OH deformation vibrations, within the carboxyl (COOH) group of L-adrenaline-D-hydrogentartrate. Laser energy densities of 1.20 and 1.70 J/cm2 modified the pharmaceutical/compound. It was found that this modification is in essence a thermal effect. The level of change showed a dependence on the laser energy density, number of accumulated laser pulses and temporal shape of the pulse.
观察了脉冲二氧化碳横向激发大气(TEA)激光诱导的KBr基质中掺入药物l -肾上腺素-d -氢庆大酸盐的变化。通过红外光谱监测样品的变化。特别注意了样品变化对所用激光能量密度的依赖性。用波长约10.6µm的两条激光线照射该药物。激光谱线与l -肾上腺素- d -氢大石酸酯羧基(COOH)内的环振动/面外OH变形振动的吸收带吻合良好。激光能量密度分别为1.20和1.70 J/cm2，修饰了药物/化合物。结果表明，这种变化实质上是一种热效应。其变化程度与激光能量密度、累积激光脉冲数和脉冲时间形状有关。
{"title":"IR Laser-Induced Changes to L-adrenaline-D-hydrogentartrate Incorporated in KBr Matrices","authors":"T. Jovanovic, M. Bogavac, B. Radak, M. Trtica","doi":"10.1080/02786270215156","DOIUrl":"https://doi.org/10.1080/02786270215156","url":null,"abstract":"Changes in the pharmaceutical L-adrenaline-D-hydrogentartrate, incorporated in KBr matrices, induced by a pulsed carbon-dioxide Transversely Excited Atmospheric (TEA) laser, were observed. Modifications of the sample were monitored via infrared spectra. Special attention was devoted to the dependence of the sample changes on the laser energy density used. The irradiation of the pharmaceutical has been performed with two laser lines at wavelengths of about 10.6 µm. The laser lines coincide well with the absorption band of the pharmaceutical, which is assigned to the ring vibrations/out-of-plane OH deformation vibrations, within the carboxyl (COOH) group of L-adrenaline-D-hydrogentartrate. Laser energy densities of 1.20 and 1.70 J/cm2 modified the pharmaceutical/compound. It was found that this modification is in essence a thermal effect. The level of change showed a dependence on the laser energy density, number of accumulated laser pulses and temporal shape of the pulse.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121212533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two techniques for rotational analysis of the nd←1b1 Rydberg spectra of H2O and D2O are discussed—a Coriolis coupled asymmetric top model for the room temperature 3d←1b1 cluster, and an extension of multichannel quantum defect theory to asymmetric tops, which is applied to recent jet cooled photoionization spectra of the nd←1b1 series converging to the (100) vibrational levels of H2O
{"title":"Rotational Analysis of the Rydberg Spectrum of Water","authors":"M. Child, R. D. Gilbert, C. Jungen","doi":"10.1155/LC.11.253","DOIUrl":"https://doi.org/10.1155/LC.11.253","url":null,"abstract":"Two techniques for rotational analysis of the nd←1b1 Rydberg spectra of H2O and D2O are discussed—a \u0000Coriolis coupled asymmetric top model for the room temperature 3d←1b1 cluster, and an extension of \u0000multichannel quantum defect theory to asymmetric tops, which is applied to recent jet cooled photoionization \u0000spectra of the nd←1b1 series converging to the (100) vibrational levels of H2O","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"39 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114113866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The evolution since 1982, of far-UV laser photoablation of polymers is described. The experimental data can be fitted by using a dynamic model which states that the irradiated interface moves at a rate proportional to the difference between, the intensity reaching it, and the ablation threshold intensity It. The screening effect of the ablated gaseous products is taken into account. The experimental etch depth versus fluence, obtained with our new quartz crystal microbalance technique, can be fitted by adjusting two parameters of this model; the mean absorption coefficient of the products β and the so-called ablation rate constant k, which is the etch rate for I=It
{"title":"Ultraviolet Laser Photoablation of Polymers: A Review and Recent Results","authors":"S. Lazare, V. Granier","doi":"10.1155/1989/18750","DOIUrl":"https://doi.org/10.1155/1989/18750","url":null,"abstract":"The evolution since 1982, of far-UV laser photoablation of polymers is described. The experimental data can be fitted by using a dynamic model which states that the irradiated interface moves at a rate proportional to the difference between, the intensity reaching it, and the ablation threshold intensity It. The screening effect of the ablated gaseous products is taken into account. The experimental etch depth versus fluence, obtained with our new quartz crystal microbalance technique, can be fitted by adjusting two parameters of this model; the mean absorption coefficient of the products β and the so-called ablation rate constant k, which is the etch rate for I=It","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114311470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The time-of-flight (TOF) spectra of Ar+ and Ar fragments produced in the photodissociation of Arn
Arn光解过程中产生的Ar+和Ar碎片的飞行时间(TOF)光谱
{"title":"Photodissociation Dynamics of Arn","authors":"T. Nagata","doi":"10.1155/1994/98627","DOIUrl":"https://doi.org/10.1155/1994/98627","url":null,"abstract":"The time-of-flight (TOF) spectra of Ar+ and Ar fragments produced in the photodissociation of Arn","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121706919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have performed resonance Raman (RR) intensity calculations of the Soret-resonant Raman spectra of Ni and Zn Porphine to investigate observed core size intensity differences in the time-resolved Soret-resonant Raman (RR) spectra of hemoglobin. It was found that the metalloporphine intensities mainly derive from the expansion of the Cα—Cm and Cβ—Cβ bonds in the excited state, and that the observed differences are mainly due to the larger core-sized heme having a decreased Cα—Cm force constant and larger excited state porphyrin ring expansion.
{"title":"Modeling the Transient Changesin the Soret-Resonant RamanIntensities of Hemoglobin DuringThe R→ T Transition","authors":"T. Rush, R. Kumble, T. Spiro","doi":"10.1155/1999/70916","DOIUrl":"https://doi.org/10.1155/1999/70916","url":null,"abstract":"We have performed resonance Raman (RR) intensity calculations of the Soret-resonant Raman spectra of Ni and Zn Porphine to investigate observed core size intensity differences in the time-resolved Soret-resonant Raman (RR) spectra of hemoglobin. It was found that the metalloporphine intensities mainly derive from the expansion of the Cα—Cm and Cβ—Cβ bonds in the excited state, and that the observed differences are mainly due to the larger core-sized heme having a decreased Cα—Cm force constant and larger excited state porphyrin ring expansion.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121802478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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