Analysis of the Coriolis interaction between ν6 and ν4 bands of ethylene-cis-d2(cis-C2H2D2) by high-resolution FTIR spectroscopy

The Fourier transform infrared (FTIR) spectrum of the ν₆ band of ethylene-cis-d₂(cis-C₂H₂D₂) was recorded with a unapodized resolution of 0.0063 cm^?1 in the 990–1100 cm^?1 region. A total of 609 transitions were assigned to this band centred at 1039.7682 ± 0.0003 cm^?1. The ν₆ band was found to be coupled to the ν₄ band by a-type Coriolis resonance. Both perturbed and unperturbed transitions were assigned and fitted to give eight rovibrational constants with high accuracy for the v₆ = 1 state with a standard deviation of 0.00097 cm^?1 using a Watson’s A-reduced Hamiltonian in the I^r representation. From a rovibrational analysis of the Coriolis interaction between the ν₆ band and non-infrared active ν₄ band of cis-C₂H₂D₂, the band centre of ν₄ at 984.9 ± 0.2 cm^?1 was derived. Furthermore, the second-order a-type Coriolis coupling constant between the two bands was obtained for the first time.     

A deep insight into arsenic adsorption over γ-Al2O3 in the presence of SO2/NO

Arsenic is easily evaporated during coal combustion, which not only raises serious environmental concerns but also results in the deactivation of catalyst in selective catalytic reduction (SCR) systems. It is a promising method to use sorbents for the capture of arsenic vapors (As₂O₃(g)) before As-containing flue gas entering SCR catalyst. However, arsenic has a strong affinity with sulfur in coal and SO₂ in the coal combustion flue gas strongly suppresses As₂O₃(g) capture by typical Ca/Fe-based sorbents. This study estimated the selective capture of As₂O₃(g) by γ-Al₂O₃ and the effects of SO₂ and NO on the arsenic adsorption were investigated. The results showed that As₂O₃(g) adsorption over γ-Al₂O₃ was effectively conducted at temperatures ranging from 300 to 400 °C. In the reacted γ-Al₂O₃, arsenic was predominantly in the form of As³⁺ through reactions with Al-O bonds and positive charged alumina ions. SO₂ was slightly adsorbed on γ-Al₂O₃, which had a limited effect on arsenic adsorption. The adsorption of SO₂ on γ-Al₂O₃ mainly occurred on the sites of hydroxyl groups (Al-OH) and few adsorbed SO₂ was bound with positive charged alumina ions. NO was catalytically oxidized by γ-Al₂O₃ and released as NO₂. Nevertheless, NO competed with As₂O₃(g) to adhere to positive charged alumina ions and strongly suppressed arsenic adsorption over γ-Al₂O₃. Fortunately, in the presence of SO₂, NO was mostly transformed into intermediate (-SO₃NO) at the sites of Al-OH on γ-Al₂O₃. As a result, the adverse effect of NO on the adsorption of As₂O₃(g) was weakened.     

An intermediate monoclinic phase and electromechanical interactions in xPbTiO3-(1−x)Pb(Zn1/3Nb2/3)O3 crystals

The elastic matching of phases in the vicinity of the morphotropic phase boundary in xPbTiO₃-(1?x)Pb(Zn_1/3Nb_2/3)O₃ crystals is investigated in an external electric field with strength E ‖ [001]. The field dependences of the unit cell parameters of the monoclinic phase are determined experimentally in the range 0≤E≤2 MV/m. The results obtained are used in analyzing specific features in the electromechanical properties of xPbTiO₃-(1?x)Pb(Zn_1/3Nb_2/3)O₃ crystals (0.08?x?0.09), in which the monoclinic phase is intermediate between the rhombohedral and tetragonal phases and can coexist with these phases. A correlation between the optimum volume concentrations of domains or twins in different two-phases states is revealed and interpreted for the first time.     

An insight into the reaction kinetics of CH3 + O2(a1Δg) and its enhancement effect on methane ignition

The reaction between CH₃ and O₂(a¹?_g) is crucial to understand the effects of electronically excited oxygen in plasma-assisted combustion of methane and other hydrocarbons. In the present work, multireference quantum chemical methods were used to investigate the potential energy surface of CH₃ + O₂(a¹?_g). The RRKM/master equation simulation was employed to compute the rate coefficients of various pathways to this reaction over the temperature range of 300–2000 K and a pressure range of 0.1–100 atm. Special attention has been paid to the nonadiabatic transition between the excited state and ground state, which directly leads to a quenching channel from CH₃ + O₂(a¹?_g) to CH₃ + O₂(X³∑_g^?). This quenching reaction has been overlooked by previous theoretical and kinetic modeling studies. We also conducted kinetic modeling to examine the effect of this reaction on the ignition enhancement of methane oxidation. Although the channel of CH₃ + O₂(a¹?_g) quenching to CH₃ + O₂(X³∑_g^?) has nonnegligible rate constants comparing with other reaction channels, modeling result with the inclusion of 5% O₂(a¹?_g) in molecular oxygen shows that the titled reactions shorten the ignition delay time of methane by more than twenty times at 900 K, 1 atm. The ignition enhancement is mainly from the chain branching channels to CH₂O + OH and CH₃O + O which has been greatly promoted by excess energy from O₂(a¹?_g). The present study uncovers the kinetic mechanism of this nonadiabatic reaction and provides reasonable rate coefficients for further kinetic modeling of plasma-assisted combustion of methane and other hydrocarbons.     

[OsⅥ(N)(NH3)4](CF 3SO3)3电化学还原过程的原位FTIR光谱研究

运用原位FTIRS,UV/Vis和电化学方法研究了乙腈溶液中[Os Ⅵ(N)(NH3)4](CF3SO3)3在GC和Pt电极上的还原过程 .结果首次在Pt电极上检测到桥氮物种ν(N≡N)的红外谱峰,位于2 019和1 970 c m-1附近,分别指认为[Ⅲ,Ⅱ]和[Ⅱ,Ⅱ]混合价桥氮锇络合物.为进一步探讨桥氮偶联过程提供了新的谱学数据.     

Monochromatic soft-x-ray-induced reactions of CF2Cl2 adsorbed on Si(111)-7 × 7 studied by continuous-time photon-stimulated desorption spectroscopy near the F(1s) edge

Continuous-time core-level photon-stimulated desorption (PSD) spectroscopy was used to investigate the monochromatic soft x-ray photoreactions of CF(2)Cl(2) adsorbed on Si(111)-7 × 7 near the F(1s) edge (681-704 eV). Sequential F(+) PSD spectra were observed as a function of photon exposure at the CF(2)Cl(2)-covered surface (dose = 2.0 × 10(14) molecules cm(-2), ～0.75 monolayer). The F(+) PSD and total electron yield (TEY) spectra of solid CF(2)Cl(2) near the F(1s) edge were also measured. Both F(+) PSD and TEY spectra depict three features in the energy range of 687-695 eV, and are assigned to the excitations of F(1s) to (13a(1) + 9b(2))[(C-Cl)(?)], (7b(1) + 14a(1))[(C-F)?] antibonding and 5p Rydberg orbitals, respectively. Following the Auger decay process, two holes are created in the C-F bonding orbitals producing the 2h1e final state which results in the F(+) desorption. This PSD mechanism, responsible for the F(+) PSD of solid CF(2)Cl(2), is used to explain the first F(+) PSD spectrum in the sequential F(+) PSD spectra. The variation of spectral shapes in the sequential F(+) PSD spectra shows the consumption of adsorbed CF(2)Cl(2) molecules and the production of surface SiF species as a function of photon exposure. The photolysis cross section of the adsorbed CF(2)Cl(2) molecules by photons with varying energy (681-704 eV) is deduced from the sequential F(+) PSD spectra and found to be ～6.0 × 10(-18) cm(2).     

Anharmonic resonance interactions in the bending manifold associated with ν3 in 13C2D2 studied by high—resolution infrared and Raman spectroscopy

The Q branch of the 2ν₂ ← ν₂ band of ¹³C₂D₂ has been recorded with an instrumental resolution of about 0.003 cm^?1 using inverse Raman spectroscopy combined with stimulated Raman pumping in order to populate the ν₂=1 state. A weak local perturbation evident in the spectrum has been attributed to the effect of an anharmonic resonance between the ν₂=2 and ν₃=ν₄=ν₅=1 Σ⁺ _g, states. To study this interaction, the components of the latter vibrational manifold (Σ⁺ _g, ^? _g and Δ_g), together with all the bending states up to (ν₄ + ν₅)=2 associated with ν₃=1, have been characterized through the analysis of their infrared spectra. Both cold and hot bands from states thermally populated at room temperature, ν₄, ν₅, 2ν₄, 2ν₅ and ν₄ + ν₅, have been recorded in the region between 2300 and 3000 cm^?1 at an effective resolution of about 0.009 cm^?1. A simultaneous analysis of all the assigned transitions has been performed on the basis of a theoretical model which takes into account the rotational and vibrational ?-type resonances within each vibrational manifold, the Darling-Dennison anharmonic resonance between the ν₃ + 2ν₄ and ν₃ + 2ν₅ states, and the anharmonic interaction between the 2ν₂ and ν₃ + ν₄ + ν₅ states.     

Rovibrational constants for the ground state and ν8 = 1 state of ethylene-d3 (C2HD3) by high-resolution FTIR spectroscopy

The Fourier transform infrared (FTIR) spectrum of the ν₈ fundamental band of ethylene-d₃ (C₂HD₃) was recorded with a unapodized resolution of 0.0063 cm⁻¹ in the wavenumber region of 840–980 cm⁻¹. By assigning and fitting a total of 738 infrared transitions using a Watson’s A-reduced Hamiltonian in the I^r representation, rovibrational constants for the upper state (ν₈ = 1) up to all five quartic centrifugal distortion terms were derived for the first time. The root-mean-square (rms) deviation of the fit was 0.00076 cm⁻¹. The ground state rovibrational constants of C₂HD₃ were also determined for the first time by a fit of 450 combination-differences from the present infrared measurements, with rms deviation of 0.00075 cm⁻¹. Local frequency perturbations were not detected in the C-type ν₈ band of C₂HD₃ which is centred at 918.73199 ± 0.00007 cm⁻¹.     

Electrostatic effects between adsorbed species—the K … Co interaction on Ni(111) as studied by infrared reflection-absorption spectroscopy

Using infrared reflection-absorption spectroscopy (IRAS), TPD and LEED, we have made a detailed study of CO coadsorbed with potassium on Ni(111). Both long range delocalized and short range localized potassium-CO interactions are observed at both low and high potassium coverages. Using the high resolution of IRAS, we estimate the lateral range of the long range K-CO interaction to be ≈ 25 CO molecules per potassium atom at the lowest potassium coverage studied. We explain the long range K-CO interaction in terms of a through-space electrostatic interaction and the observed decrease in the CO vibrational frequency in terms of the vibrational Stark effect. Finally, short range K-CO interactions, possibly due to the formation of a potassium-CO complex, are suggested by TPD and IRAS results.     

Study of the levels in 174Lu by (p, 3nγ) spectroscopy

The nuclear levels in ¹⁷⁴Lu were investigated by means of ¹⁷⁶Yb(p, 3nγ) reaction spectroscopy. Standard germanium detector techniques as well as an on-line curved crystal spectrometer were used. Six well-developed rotational bands are observed. These results confirm and extend the scheme previously obtained by direct reactions. The presented data document a study on the anomalous g-factors of the 142 d isomeric band.     

The electron spin resonance spectrum of NH(SO3 -) in γ-irradiated potassium sulphamate

The electron spin resonance spectrum of the radical NH(SO₃ ^- trapped in a single crystal of potassium sulphamate is interpreted. The hyperfine couplings for the hydrogen and nitrogen nuclei are given. The radical is planar, the unpaired electron occupying an orbital of π symmetry being predominantly a nitrogen 2p orbital.     

Time-resolved spectroscopy and energy transfer in Pr3+-doped Gd2(SO4)3·8H2O

The luminescence of Pr³⁺ in gadolinium sulfate hydrate is reported for 195 nm laser excitation. the Pr³⁺ ion acts as a sensitizer of the host lattice emission. The Pr³⁺Gd³⁺ energy transfer occurs in two different ways. In the octahydrate the transfer occurs from the lowest component of the 4f5d configuration of Pr³⁺, but in the samples with less water there is energy transfer from the¹ S _o level of Pr³⁺ to several Gd³⁺ levels. The Pr³⁺ emission in the two modifications is, of course, also strikingly different.Deceased 24 December 1994     

Study on interaction between Dy(Ⅲ)(NR)_3 complex and herring sperm DNA by spectroscopy

<正>The action mode between Dy(III)(NR)_3 and herring sperm DNA is studied by ultraviolet-visible(UVvis) and fluorescence spectra as well as electrochemistry.Double-reciprocal method studies show that the binding stoichiometry between Dy(III)(NR)_3 and DNA is 1:1,the binding constants at different temperatures are 1.15×10~5 L/mol at 25℃and 2.09×10~5 L/mol at 35℃,and the corresponding thermodynamic parameters are△_rH_m~(?) = 2.48×10~4 J/mol,△_rG_m~(?)= -2.34×10~4 J/mol,△_rS_m~(?) = 161.7 J/(mol-K),△_rS_m~(?) is the driving force in this reaction.Combined with Scatchard method and melting method,the results suggest that the interaction mode between Dy(III)(NR)_3 and herring sperm DNA is intercalation fashion and groove fashion.     

Preparation of γ-AL(OH)3 and γ-AL2O3 Nanoparticles by the Method of Pulsed Laser Ablation of Metal Aluminum in Water

Russian Physics Journal -     

Ti(SO4)2水热法制纳米SO2-4/TiO2光催化剂的光谱研究

以Ti(SO4) 2 水溶液为前驱物 ,尿素为沉淀剂 ,采用水热沉淀 加热分解 浸渍烧结法制备纳米SO2 -4/TiO2 固体超强酸光催化剂 ,并用XRD ,BET ,FTIR ,DRS和FS等对中间态粒子和产物进行表征 ,以光催化降解罗丹明B为模型反应 ,筛选制备SO2 -4/TiO2 光催化剂的优化条件。结果表明 ,用Ti(SO4) 2 为前驱物 ,水热法能在较低的温度、弱碱性介质中 ,得到纳米锐钛矿型TiO2 晶体 ;在 30 0℃下控制焙烧 4h ,基本能使水热反应副产物 (NH4) 2 SO4等分解 ,又避免H2 SO4大量的流失 ;SO2 -4负载量和烧结时间是影响SO2 -4/TiO2 光催化活性的主要因素 ,当SO2 -4负载量 11%、烧结温度 4 5 0℃时 ,制备的SO2 -4/TiO2 光催化剂活性较高 ,达P 2 5光催化剂的水平     

光解CF3I研究I(52p1/2)的动力学

本实验用YAG激光器的四倍频光,光解CF3I得到I(52P1/2)。通过测量I(52P1/2)跃迁到基态而发出的1.315 μm荧光得到I(52P1/2)的自发辐射寿命为0.0370.005s,测得CF3I、O2、He对I(52P1/2)的猝灭常数分别为0.605Pa-1s-1,2 .25Pas-1及0.22Pas-1。     

光解CF3I研究I(52p1/2)的动力学

 本实验用YAG激光器的四倍频光,光解CF₃I得到I(5²P_1/2)。通过测量I(5²P_1/2)跃迁到基态而发出的1.315 μm荧光得到I(5²P_1/2)的自发辐射寿命为0.0370.005s,测得CF₃I、O₂、He对I(5²P_1/2)的猝灭常数分别为0.605Pa^-1s^-1,2 .25Pas^-1及0.22Pas^-1。     

The ν12 band of ethylene-1-C (CCH4) by high-resolution FTIR spectroscopy

The Fourier transform infrared (FTIR) spectrum of the ν₁₂ fundamental band of ethylene-1-¹³C (or ¹³C¹²CH₄) was recorded with an unapodized resolution of 0.0063 cm⁻¹ in the wavenumber region of 1360-1520 cm⁻¹. Rovibrational constants for the upper state (ν₁₂ = 1) up to five quartic and two sextic centrifugal distortion terms were derived for the first time by assigning and fitting a total of 879 infrared transitions using a Watson’s A-reduced Hamiltonian in the I^r representation. The root-mean-square deviation of the fit was 0.00066 cm⁻¹. The ground state rovibrational constants were also determined by a fit of 523 combination-differences from the present infrared measurements, with a rms deviation of 0.00090 cm⁻¹. The A-type ν₁₂ band which is centred at 1439.34607 ± 0.00004 cm⁻¹ was found to be relatively free from local frequency perturbations. From the ν₁₂ = 1 rovibrational constants obtained, the inertial defect Δ₁₂ was found to be 0.242826 ± 0.000002 μŲ.     

Photoinduced transformations in (As1–xBix)2S3 glass observed by Raman spectroscopy

Raman spectra of (As_1–xBi_x)₂S₃ glass samples with x ≤ 0.2 measured at the excitation with above-bandgap (532 nm) laser light at a relatively low power density (P_exc = 4 kW/cm²) clearly confirm the amorphous character, thereby markedly extending the known compositional interval of existence of the (As_1–xBi_x)₂S₃ glass previously known (x ≤ 0.06). Spectra measured at an increased P_exc (40 kW/cm²) reveal a photostructural transformation in the illuminated area of the glass leading to an additional contribution of Bi–S bonds as well as to an increasing number of cage-type As₄S₄ units with homopolar As–As bonds. A number of new features in a broad range up to about 1,000 cm⁻¹, which emerge in the Raman spectra of the (As_1–xBi_x)₂S₃ glasses with high (x ≥ 0.14) Bi content and increase in intensity with the exposure time, are related to a photochemical transformation, namely, oxidation of arsenic and sulphur on the (As_1–xBi_x)₂S₃ glass surface with formation of units containing arsenate AsO₄³⁻ and sulphate SO₄²⁻ ions. These processes are irreversible and occur only in the presence of a sufficient amount of bismuth.     

Submillimeter-wave spectroscopy of VN (XΔr) and VO (XΣ): A study of the hyperfine interactions

The pure rotational spectra of VN (X³Δ_r) and VO (X⁴Σ⁻) have been recorded in the frequency range 290-520 GHz using direct absorption spectroscopy. These radicals were synthesized in the gas-phase from the reaction of VCl₄ with either N₂ or H₂O in an AC discharge. Seven rotational transitions were recorded for each molecule; in both sets of spectra, fine and hyperfine structures were resolved. The data sets for VN and VO were fit with Hund’s case (a) and case (b) Hamiltonians, respectively, and rotational, fine structure, and hyperfine constants determined. For VN, however, an additional hyperfine parameter, Δa, was necessary for the analysis of the Ω = 2 sublevel to account for perturbations from a nearby ¹Δ state, in addition to the usual Frosch and Foley constants. Determination of Δa suggests that the ¹Δ state lies ∼3000 cm⁻¹ above the ground state. In VO, the hyperfine structure in the F₂ and F₃ components was found to become heavily mixed due to an avoided crossing, predicted by previous optical studies to be near the N = 15 level. The hyperfine constants established for these two molecules are consistent with the proposed σ¹δ¹ and σ¹δ² electron configurations.