Selective effects of homogeneous and heterogeneous reactions in the system N21-CO

In the system N₂¹-CO, effects arising only from the reactions in the homogeneous phase have been isolated in a reactor with inert walls. After an induction period of 0.13 s, they involve a stationary rate of enhancement of N₂(B³Π_g) and N(⁴S) concentrations according to the reactions N₂(X¹Σ_g⁺)_v¹+CO→ CO(X¹Σ⁺)_v1 + N₂(X¹Σ_g⁺ and CO(X¹Σ⁺)_v1 + N₂(A³Σ_u⁺) → N (⁴S) + N(⁴S) + CO(X¹Σ⁺).In a reactor with active walls, both the above reactions in the homogeneous phase and heterogeneous reactions due to CO adsorbed on the walls are involved according to CO_ads + N₂(X¹Σ_g⁺)_{v1 ads or not} → CO(X¹Σ⁺)_v1 + N₂(X¹Σ_g⁺ and N(⁴S) + N(⁴S) + CO_ads → N₂(X¹Σ_g⁺) + CO(X¹Σ⁺)N(⁴S) + CO_ads → N₂(X¹Σ_g⁺) + CO(X¹Σ⁺). In this case, the rate of enhancement is not stationary. Furthermore, for cylindrical reactors with large diameters, the two types of reaction do not interact and their effects are additive.     

A global potential energy surface for H2S+(X 4A′′) and quasi-classical trajectory study of the S+(4S) + H2(X1Σ+g) reaction

A novel global potential energy surface for H₂S⁺(X?⁴A″) based on accurate ab initio calculations is presented. Energies are calculated at the multi-reference configuration interaction level with Davidson correction using aug-cc-pVQZ basis set plus core-polarisation high-exponent d functions. A grid of 4552 points is used for the least-square fitting procedure in the frame of a many-body expansion. The topographical features of the new potential energy surface are here discussed in detail. Such a surface is then employed for dynamic studies of the S(⁴S) + H₂(X?¹Σ⁺_g) →SH⁺(X?³Σ^?) + H(²S) reaction using the quasi-classical trajectory method. State specific trajectories are calculated, for both ground and ro-vibrationally excited initial states of H₂(X?¹Σ⁺_g). Corrections to the zero point energy leakage of the classical calculations are also presented. Calculated reaction cross sections and rate constants are here reported and compared with available literature.     

Electron-vibrational energy exchange in collisions of electronically excited N2(A 3Σ u + ) molecules with Zn(X 1 S) atoms

The interaction matrix between the N₂ molecule in the X ¹Σ _g ⁺ and A ³Σ _u ⁺ states and the Zn atom in the ¹ S and ³ P states calculated earlier by the asymptotic method was used to find the rate constants for the electron-vibrational energy exchange N₂(A ³Σ _u ⁺ , v) + Zn(¹ S) → N₂(X ¹Σ ₈ ⁺ , v′) + Zn(³ P). The calculations were performed by the transition state method, and the probabilities of transitions between intersecting electron-vibrational terms of the system in motion along the reaction coordinate were determined by the Landau-Zener equation. The calculated electron excitation transfer constants between N₂(A ³Σ _u ⁺ , v = 1, 0) and Zn(¹ S) over the temperature range 300–900 K were on the order of 10^?11?10^?12 cm³/s.     

Interaction of Zn atoms in the 1 S and 3 P states with N2 molecules in the X 1Σ g + and A 3Σ u + states at moderate distances between the atom and molecule

An asymptotic method was used to derive analytical expressions for the matrix elements of interaction between the N₂ molecule in the X ¹Σ _g ⁺ and A ³Σ _u ⁺ electronic states and the Zn atom in the ¹ S and ³ P states. Quadrupole-quadrupole, dispersion, and exchange interactions were taken into consideration. The character of the set of diabatic vibronic potential energy surfaces of the system suggests that the energy transfer in the process N₂(A ³Σ _u ⁺ ) + Zn(¹ S) → N₂(X ¹Σ _g ⁺ ) + Zn(³ P) may prove to be rather effective.     

Ultraviolet to infrared refractive indices of tetragonal double tungstate and double molybdate laser crystals

Sellmeier parameters of thirteen tetragonal (space group $I\overline{4}$ ) double tungstate and double molybdate laser crystals with M⁺T³⁺(X⁶⁺O₄)₂ composition have been calculated using the room temperature refractive indices determined from the ultraviolet band gap of the crystals to ????2 ??m. All considered crystals are uniaxial but only crystals with Bi in their composition show a significant birefringence (??n>10^?2). The refractive index value increases for the sequence T³⁺=La, Y, Gd, Lu, and Bi independently of the M⁺ and X⁶⁺ cation pair. Implications for the design of laser waveguides and laser pulse dispersion are discussed.     

How learn the branching ratio X(3872) \to D*^0 \bar D^0 + c.c.

Enfant terrible of charmonium spectroscopy, the resonance X(3872), generated a stream of interpretations and ushered in a new exotic XYZ spectroscopy. In the meantime, many (if not all) characteristics of X(3872) are rather ambiguous. We construct spectra of decays of the resonance X(3872) with good analytical and unitary properties which allows to define the branching ratio of the \(X(3872) \to D*^0 \bar D^0 + c.c.\) decay studying only one more decay, for example, the X(3872) → π⁺π^? J/ψ(1S) decay. We next define the range of values of the coupling constant of the X(3872) resonance with the \(X(3872) \to D*^0 \bar D^0 + c.c.\) system. Finally, we show that our spectra are effective means of selection of models for the resonance X(3872).     

Theoretical Study of the Dynamic Stark Effect on Dissociation of CsI

The influence of the dynamic Stark effect on the dissociation of CsI is theoretically studied by the time-dependent wave-packet method. After a pump pulse induces a dissociating wave packet that propagates through both the ionic channel X0⁺(Cs ⁺(¹ S ₀)?+?I ⁺(¹ S ₀)) and the covalent channel A0⁺(Cs(² S _1/2)?+?I(² P _3/2)), a Stark pulse is applied to control the diabatic-dissociation dynamics. The first-order non-resonant non-perturbative dynamic Stark effect gives control over the break up, the dissociation probabilities in the two channels being controlled by the delay between the pump and Stark pulses. With a 720-fs delay, the dissociation probability through channel A is greatly enhanced.     

The bΣ(b0) → XΣ(X10,X21) and aΔ(a2) → X21 transitions of AsBr

Emission spectra of the b¹Σ⁺(b0⁺) → X³Σ⁻(X₁0⁺,X₂1) and a¹Δ(a2) → X₂1 transitions of AsBr have been measured in the near-infrared spectral region with a Fourier-transform spectrometer. The arsenic bromide radicals were generated in fast-flow systems by reaction of arsenic vapor (As_x) with bromine and were excited by microwave-discharged oxygen. The most prominent features in the spectrum are the Δv = +1,0,−1, and −2 band sequences of the b¹Σ⁺(b0⁺) → X³Σ⁻(X₁0⁺) transition in the range 11 700-12 700 cm⁻¹. With lower intensities, the Δv = 0 and −1 sequences of the b¹Σ⁺(b0⁺) → X³Σ⁻(X₂1) sub-system show up in the same range. Further to the red, between 6000 and 6700 cm⁻¹, the Δv = 0, +1, and −1 sequences of the hitherto unknown a¹Δ(a2) → X₂1 transition are observed. Analyses of medium- and high-resolution spectra have yielded improved molecular constants for the X₁0⁺, X₂1, and b0⁺ states and first values of the electronic energy and the vibrational constants of the a2 state.     

Refined interpretation of broadband radiation from a gas-discharge plasma of a krypton-xenon mixture

The earlier interpretation of the broadband continuum observed in the VUV emission spectra of a gas-discharge plasma in a Kr + Xe mixture is refined. On the assumption that this continuum is caused by the bound-free transitions v,0⁺(³ P ₁) → ε, 0⁺(¹ S ₀) in KrXe* and Xe₂ molecules, the distribution of the population over the vibrational levels v of the states 0⁺(³ P ₁) of both molecules is obtained and the vibrational temperature for different methods of excitation of the spectrum is determined. Internuclear potentials 0⁺(³ P ₁) and 0⁺(¹ S ₀) available from the literature are used. To improve the agreement between the calculated and experimental spectra, it is proposed to modify the positive branch of the potential curve 0⁺(¹ S ₀) of the KrXe* molecule.     

Search for ξ(2.2) andX(2.2) in radiative decays of ϒ-meson

The results of an experiment on the search for ξ(2.2) andX(2.2) in the radiative decays of the Υ-meson are presented. The experiment was carried out with the MD-1 detector at the VEPP-4 collider. An upper limitB(Υ→γξ)B(ξ→K ⁺ K ^?)<2·10^?4 is obtained at 90% C.L. Results are presented on the search for the decay Υ→γX, X→ ?? not previously investigated. For this decay the upper limitB(Υ→γX)B(X→??)<3·10^?3 is obtained at 90% C.L.     

Absolute intensities and pressure broadening coefficients measured at different temperatures for the 201II ← 000 band of 12C16O2 at 4978cm-1

Absolute line intensities and self-broadening coefficients have been measured at 197° and 294°K for the 201_II ← 000 band of ¹²C¹⁶O₂ at about 4978cm^-1. The vibration-rotation factor (F_VR), the purely vibrational transition moment (∣R(O)∣), and the integrated band intensity (S_band) are deduced from the measurements. The results are: F_VR(m)=1+(0.24±0.08)x10^-4m+(0.55+0.21)x10^-4m², ∣R(O)∣= (4.340±0.008x10^-3 debye, S_band=96372±190cm^-1km^-1atm^-1_STP. The results for self-broadening coefficients, as well as for individual vibration-rotation lines, are presented in the text.     

用MRCI方法研究CS+同位素离子X2Σ+和A2Π态的光谱常数与分子常数

利用内收缩多参考组态相互作用方法和价态范围内的最大相关一致基aug-cc-pV6Z, 在0.05—0.60 nm的核间距范围内计算了CS⁺离子X²Σ+和A²Π态的势能曲线. 利用CS⁺离子的势能曲线并在同位素质量修正的基础上, 拟合出了X²Σ+和A²Π态的同位素离子^{1 关键词： 同位素识别 势能曲线 光谱常数 分子常数}     

Thermoelectric power of the vitreous electrolyte (AgI)0.79(Ag2O.B2O3)0.21

We have determined the thermoelectric power ? of the high ionic conductivity glass (AgI)_0.79(Ag₂O.B₂O₃)_0.21; ? is negative throughout the investigated T range, 320–500 K. The heat of transport of the mobile Ag⁺, Q_Ag, taken as the slope of the straight line fitting ? versus 1/T, is quite lower than the activation energy obtained from conductivity data, viz. Q_Ag = 2.81 kcal/mole^-1 < E_act = 4.34 kcalmole^-1. To circumvent this discrepancy, the analysis of the experimental data is carried out as follows: (i) it is supposed that Q_Ag = E_act in agreement with the free ion theory for solid electrolytes; (ii) the vibrational part of the silver ion entropy, S(Ag⁺, vib), is assumed to be equal to the entropy of silver, S(Ag); (iii) on the ground of a structural model for this kind of glasses, the ideal configurational entropy of the mobile Ag⁺, S(Ag⁺, conf)_id, is evaluated through a statistical approach. The ideal ionic entropy is defined as S(Ag⁺)_id = {S(Ag⁺, vib) + S(Ag⁺, conf)_id}; (iv) the difference {S(Ag⁺)_exp - S(Ag⁺)_id} is viewed as an excess entropy and is described according to the classical model of the regular solutions.     

Investigation of the diffractive reaction p + N → [∑+ K 0] + N at the proton energy of E p =70 GeV and observation of the decay process X(2000) → ∑+ K 0

The diffractive reaction p + N → [∑⁺ K ⁰] + N induced by 70-GeV protons is investigated at the SPHINX facility. The measured mass spectrum of the ∑⁺ K ⁰ system originating from this reaction shows a resonance structure with a mass of M=1995±18 MeV and a width of Γ=90±32 MeV. The cross section for the formation of this structure is found to be σ=182±38 nb per target nucleon. These data comply well with the results that we obtained previously in studying the reaction p + N → [∑⁰ K ⁺] + N, where we observed the formation of the X(2000) → ∑⁰ K ⁺ state, a candidate for an exotic baryon with hidden strangeness. The measured ratio R of the two branching fractions, R = Br[X(2000) → ∑⁺ K ⁰]/Br[X(2000) → ∑⁰ K ⁺] = 1.91 ± 0.38, is consistent with the value of R=2 expected for an isospin-1/2 baryon.     

Characteristics of d + α Bound and Resonant States from Analytic Continuation of the Effective-Range Expansion

In the present work one- and two-channel approaches using the expansion of the effective-range function K(E) in powers of energy E are applied to obtain the asymptotic normalization coefficients (ANCs) and vertex constants (VCs) for the d + α system. The coefficients of the K(E) expansion are found by fitting the d α phase shifts. By analytic continuation of K(E) thus obtained to the corresponding poles the ANCs and VCs for D wave d α resonances with J ^π = 1⁺, 2⁺, 3⁺ are calculated for the first time. The 1⁺-resonance and the bound state of ⁶Li (J ^π = 1⁺) are considered jointly in the two-channel (S + D) effective-range approach and the ANCs and VCs for the ground ⁶Li state are found.     

Virasoro type Lie algebras and deformations

The first and second cohomologies of Cartan Type Lie algebras with coefficients in irreducible tensor modules are calculated. The spaceH ¹(L, U) is interpreted as a space of deformations of (L, U)-modules.H ²(L, L)≠0 ifL=S ₂,S ₂ ⁺ orL=H _n ,H _n ⁺ . Lie algebra of divergenceless vector fieldsS ₂ ⁺ has only one nontrivial local deformation. The two-sided simple hamiltonian algebraH _n has 2n ²+n new local deformations in addition to Moyal cocycle. The Lie algebrasL=W _n (n>3),S _n?1(n>2),H _n (n>1),K _n+1(n>1) have 3, 1, 1, 3 nonisomorphic tensor modules with irreducible bases and nonzero 1-cohomologies; respectively, the corresponding numbers for 2-cohomologies are 9, 6, 7 and 9.     

Nuclear-medium modification of the ρ0(1S) and ρ′(2S) mesons in coherent photo-and electroproduction: Coupled-channel analysis

We study medium modifications of the dilepton e ⁺ e ^? and μ⁺μ^? mass spectra in coherent photo-and electroproduction of ρ⁰(1S)-and ρ′(2S)-meson resonances on nuclear targets. The analysis is performed within the coupled ρ⁰(1S), ρ′(2S), ... channel formalism, where nuclear modifications derive from off-diagonal rescatterings. We find that the effect of off-diagonal rescatterings on the shape of the dilepton-mass spectrum in the ρ⁰(1S)-meson mass region is only marginal, but it is very important in the ρ′(2S) mass region. The main off-diagonal contribution in the ρ′(2S) mass region comes from the sequential mechanism γ* → ρ⁰(1S) → ρ′(2S), which dominates ρ′(2S) production for heavy nuclei. Our results also show that, in the ρ′(2S) mass region, there is a considerable interference of the Breit-Wigner tail of the amplitude for the decay ρ⁰(1S) to e ⁺ e ^? and μ⁺μ^? with the amplitude for the decay of ρ′(2S) to e ⁺ e ^? and μ⁺μ^?.     

Eine scheinbare Abschwächung der Lokalitätsbedingung

For a hermitean, scalar, tempered fieldA(x) the locality axiom can be replaced by the following condition: For any two natural numbersn andj with 1≦j<n and for any configurationX(n, j):X ₁, ...,X _j?1,X _j ,X _j+1,X _j+2, ...X _n that is totally space-like in both orders: 1, ...,j?1,j, j+1,j+2, ...,n and 1, ...,j?,j+1,j,j + 2, ...,n there exist constants α(n,j)>2,C(X(n, j))>0,h(X(n, j))>0 such that with \(x_k = X_k \sqrt { - x^2 } \) : $$\begin{gathered} |\langle A(x_1 ) \ldots A(x_{j - 1} )[A(x_j ), A(x_{j + 1} )] A(x_{j + 2} ) \ldots A(x_n )\rangle |< \hfill \\ \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,< C(X(n, j)) exp\{ - h(X(n, j))\sqrt { - x^2 } ^{\alpha (n, j)} \} \hfill \\ \end{gathered} $$ for ?x ²>1.     

Short-Range Characterization of the MeAr (Me=Zn, Cd) Ground-State Potentials from Fluorescence Spectra

First-time observed D1(¹Π)_v′=10→X0⁺(¹Σ) fluorescence in ZnAr, and A0⁺(³Π)_v′=4→X0⁺ and D1(¹Π)_v′=7,8→X0⁺ fluorescence in CdAr van der Waals (vdW) molecules were produced in a continuous supersonic molecular beam crossed with a pulsed dye-laser beam, following excitation of single vibronic levels. The dispersed fluorescence spectra displayed characteristic Condon internal diffraction (CID) patterns consisting of bound-free, reflection type, continuous spectra, and, in certain cases, bound-bound discrete features. An analysis of the A0⁺→X0⁺ and D1→X0⁺ bound-bound spectra indicates that Morse functions are adequate representations of the X0⁺ potential energy (PE) curves below their dissociation limits. In simulation of the A0⁺→X0⁺ and D1→X0⁺ bound-free spectra, the Morse, Lennard-Jones L-J(n−6), and Maitland-Smith M-S(n₀,n₁) functions were tested, and the respective M-S(11.3, 9.0) and M-S(10.6, 7.0) potentials were found to be good representations for the repulsive walls of the X0⁺ PE curves of ZnAr and CdAr, respectively, over the short range, R=2.45-4.38 Å (ZnAr) and R=2.85-4.31 Å (CdAr), of internuclear separations.     

Comments on the measurements of vibrational intensity in the photoelectron spectra of N2 and CO,for the ionic ground state

Over 50 experimental values of the photoelectron intensity I(v′ = 1) (normalized to I(v′ = 0) equal to 100) for the N₂⁺, X²Σ_g⁺ photoelectron band, as well as 17 values of I(v′ = 1) for CO⁺, X²Σ⁺, are gathered or calculated from literature data, compared and discussed. Differences in the types of analyzer used, the instrumental conditions, the character of the UV light employed and the type of possible intensity corrections make such a comparison difficult, leave unexplained discrepancies and show the necessity of more systematic experimental investigations.