Pressure broadening parameters of the hydroxyl radical A 2 Σ+ (υ’=0) ← X 2 Π3/2 (υ=0) transitions at ca. 308 nm

Pressure broadening widths and pressure-induced frequency shifts for the hydroxyl radical Q11([see full textsee full text]), Q21([see full textsee full text]), Q11(2), Q21(2) absorption lines in the A band at ca. 308 nm have been determined in the presence of a variety of gases (N2, Ar, Ne and He). Hydroxyl radicals were formed using either a microwave discharge or a vacuum ultra-violet photolysis of water vapour and were detected using direct absorption spectroscopy with a bandwidth normalised noise equivalent absorption sensitivity of 5 ×10-5 Hz-1/2. A tunable external cavity diode laser at 835 nm and a single-frequency continuous-wave intracavity frequency-doubled diode laser at 488 nm were used to produce tunable continuous-wave light at 308 nm by sum-frequency generation in a -BaB2O4 crystal.     

Measurements of rotational energy transfer and quenching in OHA 2 σ +,υ′ = 0 at elevated temperature

Total rotational energy transfer rates have been measured at 1330 K for specific rotational levels in the OHA ^{2 +}, = 0 state in collisions with H₂O. Rotational levels ranging fromN = 0 to 15 were studied. Measurements were performed in the post-flame region of a stoichiometric H₂/O₂/He flame operating at 25 mbar. Quenching rates following excitation of individual upper rotational states were also measured. The RET and quenching rates both exhibit monotonic decreases with increasing rotational quantum number.     

Radiative lifetimes for the A2Σ+ (v′ = 0–7) and D2Σ+ (v′ = 0–5) Rydberg states of NO

Intensities for the γ(A²Σ⁺?→?X²Π), ε(D²Σ⁺?→?X²Π) and (D²Σ⁺?→?A²Σ⁺) bands for NO have been calculated using the Molecular Quantum Defect Orbital (MQDO) methodology. Radiative lifetimes for the A²Σ⁺ and D²Σ⁺ vibrational Rydberg states have also been determined. The present results are in excellent accord with measurements available in the literature. Additionally, predictions for a number of unknown intensities and radiative lifetimes are made, given their potential usefulness.     

Quasi-classical rate constants for the inelastic process O2(υi≫ 1) + O2 → O2(υf) + O2

Rate constants have been calculated using quasi-classical trajectories (QCT) for the vibrational relaxation of highly excited O₂:O₂(X³Σ?,v_i) + O₂(X³Σ?,0) → O₂(X³Σ?,v_f) + O₂(X³Σ?) with 22 ≤v_i≤28. The present full-dimensional QCT results agree very well with recent quantum reduced dimensionality calculations, giving further support to the hypothesis that the observed experimental jump in depletion rates would be due partially to enhanced vibrational relaxation.     

双层量子霍尔系统在填充因子υ=1/2态的涡流解(英文)

以双层系统的ZHK 模型为基础,研究了双层量子霍尔系统在朗道填充因子取υ = 1=2 这种状态的静态涡流解。ZHK模型是一种包含Chern-Simons 规范相互作用的有效理论。为了简便,假定涡流具有柱对称的结构,随后写出了无量纲的非线性运动方程组,并分析了解的渐进行为。另外,在自对偶条件下,确定了自耦合常数的形式,并写出了关于密度的自对偶方程。最后,使用数值方法找到了类型分别为(0,1),(0, -1),(1,-1) 和(-1,-1) 的涡流解。发现拓扑数为(1,-1) 的涡流是不稳定的,它会衰变为(1,0) 和(0,-1) 两种涡流。数值结果表明,拓扑数为(0,-1)和(-1,-1)的涡流确实是自对偶涡流解。We investigate the static vortex solutions of a bilayer quantum Hall state at the Landau-level filling factor υ = 1=2. This work is based on the ZHK model, which is an effective field theory including Chern-Simons gauge interactions. We deduce the dimensionless nonlinear equations of motion for vortices possessing cylindrically symmetry, and analyze the asymptotical behaviors of solutions. Additionally, we analyze the values of critical coupling constants under the self-dual condition, and obtain the self-dual equations. Finally, vortices of type (0,1),(0, -1),(1,-1) and (-1,-1) are solved with numerical methods. We reach the conclusion that vortex of type (11,-1) is unstable, which will decay to (1,0) and (0,-1). The vortices of type (0,-1) and (-1,-1) are self-dual solutions from numerical results.     

NO(X2Π1/2,3/2)υ=1←0塞曼跃迁谱及其特性研究

根据塞曼效应理论和激光磁共振光谱技术(LMR)的基本原理,讨论了双原子分子2П态的塞曼效应特性并导出了解释分子塞曼跃迁的简明代数拟合方程,用这些方程对14N16O(X2Π1/2,3/2)及15N16O(X2Π3/2) (υ=1←0)的LMR谱线进行数据拟合,得到塞曼跃迁上、下子能级的gJ因子值和二级塞曼效应因子k2.将按Hund耦合情形(a)及过渡情形(ab)的理论和拟合方程计算出的磁场位置分别与实验结果相比较,结果表明对NO分子而言,过渡情形(ab)能较真实反映它的耦合情况,且在较高强度磁场下,必须计及二级塞曼修正.验证了采用上述代数拟合方程实现新分子LMR谱线标识和指认的可靠性,并提供了系统的处理方法.     

The S21 lines of the A2Σ+ (v′ = 1)←X2Π (v″ = 0) transitions of OH and OD

The S₂₁ lines of the OH radical for the A²Σ⁺ (v′ = 1)←X²Π (v″ = 0) transition have been observed in the 278–280 nm region from the laser-excitation spectrum. The OH radical was generated from either the H + NO₂ or the H + O₃ reaction in a flow system and the fluorescence passing through a 309.6 nm interference filter was detected with a photomultiplier-boxcar integrator arrangement. The weak S₂₁ lines were observed at laser energies above 0.2 mJ. The observed peak wavenumbers are in excellent agreement with those predicted for the S₂₁ bands of the A (v>′ = 1)←X (v″ = 0) transition from the known spectroscopic parameters. Observation of the corresponding S₂₁ system for OD in the 286.0–286.9 nm region further confirms this assignment. The relative absorption cross-sections of about one-tenth those of the P₁ lines are in good agreement with theoretical considerations.     

用“υ t／2=υ^-”巧解匀变速直线运动问题

匀变速直线运动的公式众多，一题多解的题例广泛，能灵活应用匀变速直线运动的规律解题也是一种对思维能力的训练．在众多的公式中，“υ t/2=υ^-”——即在某段时间内的平均速度等于这段时间中间时刻的瞬时速度——有着较广泛的应用，有时利用其解题能使问题变得简明，使问题得以迅速解决．现举例说明如下．     

The infrared spectrum of 12C2HD: the bending states up to υ4 +υ5 =3

The infrared spectrum of ¹²C₂HD has been recorded at high resolution between 450 and 2100?cm^?1 by Fourier transform spectroscopy. The ν₄ and ν₅ bending fundamental bands together with overtones, combination bands and associated hot bands involving modes up to υ_tot?=?υ₄?+?υ₅?=?3 have been identified. Altogether, 43 vibrational bands have been analysed, leading to the spectroscopic characterization of the ground state and of 18 vibrationally excited states. They include all the components of the vibrational manifolds up to υ_tot?=?3, with the exception of the υ₄?=?3, ??=?±3 state. A simultaneous fit of all the assigned transitions has been performed. The adopted model includes vibration and rotation ?-type interaction resonances. The determined spectroscopic parameters reproduce the assigned wavenumber transitions with RMS values close to the estimated experimental uncertainties.     

The FeH radical: rotational assignment of the a6A Δ(ν = 2) and b6II (ν = 1) levels

A dispersed fluorescence study of the FeH radical at near ambient (～450 K) temperature has identified the g⁶Φ-a ⁶δ (0, 2) and g⁶Φ-b⁶II (0, 1) bands in the orange region of the spectrum. The corresponding bands with upper state e⁶II are located at about 640nm in the red. High resolution measurements in LIF have enabled the assignment of around 275 lines to these four transitions. Analysis of these bands has provided a second vibrational interval for the a⁶δ state and a first vibrational interval for the b⁶II state as 1536cm^?1 and 1542cm^?1, respectively. Term values have also been measured for a set of levels with a tentative assignment to c⁴Φ_9/2 (ν = 1).     

Syntheses and structure characterization of inorganic/organic coordination polymers: Ag(dpa), Co(O3PH)(4,4′-bpy)(H2O), Zn(O3PH)(4,4′-bpy)0.5 and Mn[O2PH(C6H5)]2(4,4′-bpy) (dpa=2,2′-dipyridylamine; 4,4′-bpy=4,4′-bipyridine)

Four novel coordination polymers: Ag(dpa) I, Co(O₃PH)(4,4′-bpy)(H₂O) II, Zn(O₃PH)(4,4′-bpy)_0.5 III and Mn[O₂PH(C₆H₅)]₂(4,4′-bpy) IV (dpa=2,2′-dipyridylamine; 4,4′-bpy=4,4′-bipyridine), were synthesized by microwave heating and characterized by X-ray crystallography. I crystallizes in monoclinic space group P21/n with a=11.576(2) Å, b=5.585(2) Å, c=15.243(4) Å, β=109.00(2)°, V=931.8(3) ų. II crystallizes in monoclinic Cc space group with a=22.477(7) Å, b=5.280(1) Å, c=10.404(4) Å, β=96.08(3)°, V=1227.8(7) ų. III crystallizes in monoclinic P21/c space group with a=9.758(2) Å, b=7.449(3) Å, c=10.277(2) Å, β=100.02(2)°, V=735.6(4) ų. IV crystallizes in monoclinic space group P2/c with a=10.174(1) Å, b=11.817(3) Å, c=18.784(4) Å, β=102.14(1)°, V=2207.8(8) ų. I consists of linear metal–metal chains wrapped by dpa ligands. II and III consist of two-dimensional M^II(O₃PH) inorganic sheets cross-linked by 4,4′-bpy ligands, while IV is formed by Mn[O₂PH(C₆H₅)]₂ sheets cross-linked by 4,4′-bpy ligands. I exhibits two-step thermal decomposition at ~200 and ~250°C, resulting in the reduction of Ag⁺ to Ag metal. II loses its coordination water at ~100°C, leaving vacant coordination sites at Co²⁺ ions, while the original framework remains intact. The removal of 4,4′-bpy in II–IV occurs at elevated temperatures above 250, 200 and 400°C respectively.     

纳米级发光材料A2SnO4(A=Ca,Sr,Ba):Eu发光性质的研究

采用络合溶胶-凝胶法制备出系列纳米级发光材料A2SnO4(A=Ca,Sr,Ba):Eu.并采用相关光谱、X射线衍射(XRD)、荧光光谱(PL)对所制备的纳米发光粉体进行表征.结果表明:制备的纳米发光粉体的粒径均匀,集中在100 nm左右;XRD结果证明碱土金属锡酸盐结构均为具有确定结构的单一物相;并且这些发光粉体的性质与碱土金属离子的半径密切相关.     

A=2反应堆中氘氚燃烧等离子体特性

人们注意到，实验反应堆ITER-FEAT的环径比A≈3，而球形环的环径比接近1．4，后者可以稳定约束更高的比压值，但其工程问题变得很棘手。最近一些研究表明环径比A接近2的托卡马克系统(在目前的实验研究和理论研究中仍是空白)具有一些非常有意义的品质，例如，对于破裂不稳定性更安全，具有高的自举电流比，以及提高反应堆的经济竞争力(甚至可以采用常规磁体)，等等。     

Nd:NaR(WO4)2晶体生长(R=Bi,Y)

采用提拉法生长出了掺钕钨酸铋钠[Nd:NaBi (WO4)2,简称Nd:NBW]和掺钕钨酸钇钠[Nd:NaY (WO4)2,简称Nd:NYW]晶体,并给出了制备无开裂优质Nd:NBW和Nd:NYW晶体的最佳生长工艺参数.从XRD分析得到Nd:NBW和Nd:NYW晶体的晶胞参数,并分析了晶体的拉曼光谱,认为二者结构基本相同,为四方晶系、白钨矿结构、I41/a空间群.由吸收光谱可以看出,Nd:NBW在802nm有较强的吸收峰,Nd:NYW在804nm、752nm、586nm附近有较强、较宽的吸收峰,二者均适合于LD泵浦;计算了晶体中Nd3 的吸收截面积.     

The potential for which E n 1 ′ 12=E n 2 ′ l1 in nonrelativistic quantum mechanics

The answer is provided to the question ‘What is the potential for which E _{n 1} ^′ l₂=E _{n 2} ^′ l₁ in nonrelativistic Quantum Mechanics?’     

The dipnictenes R-E=E′-R′ (E=P,As, Sb,Bi) revisited: a TDDFT and multi-reference study of some aspects of its electronic spectroscopy

Compounds with double bonds Terp-E=E′-Terp (E, E'=P, As, Sb or Bi; Terp=-C₆H₃-2,6 (C₆H₅)₂) have been studied using DFT. These compounds have been used as a model for other compounds with larger substituents. Some bands of its electronic spectroscopy have been calculated using TDDFT, and the results show high correlation with experimental data, when available. In Bi-containing compounds, the origin of some weak bands in the calculated spectra and also in experimental data is unclear. An assignation of these bands is suggested, wedding the experimental data with calculated and theoretical results. These bands could be weak singlet–triplet transitions, partially allowed by spin-orbit coupling only in Bi-containing compounds. A theoretical estimation of the energy of these bands is achieved using CASSCF and MR-MP2.     

A new ternary carbide Dy2Mn2−xC5 (x=0.6): Preparation,crystal structure,and physical properties

The crystal structure, magnetic and electrical transport properties of the new ternary compound Dy₂Mn_2−xC₅ (x=0.6) have been investigated. According to X-ray powder diffraction the carbide crystallizes in its own structure type, space group I4/mmm, a=3.6421(2), c=15.7713(9) Å, R_B=0.062, R_p=0.134. The crystal structure contains isolated carbon atoms and C₂ dimers in square-bipyramidal holes and distorted bicapped square anti-prisms, respectively. Manganese atomic positions in the structure were found to be not fully occupied. Physical properties were studied in the temperature range down to 0.4 K. The electrical resistivity of Dy₂Mn_2−xC₅ (x=0.6) reveals its basically metallic nature with a positive temperature coefficient above about 30 K. A resistive anomaly at around 20 K indicates the appearance of an antiferromagnetic superzone boundary gap at low temperatures. A phase transition towards long range antiferromagnetic magnetic ordering below 19 K is further revealed by heat capacity and ac susceptibility data. Magnetization data refer to a non-trivial nature of the magnetic ground state which may be caused by the intrinsic structural disorder associated with random vacancies at the Mn site.