High spin states in 63Cu

Excited states of ⁶³Cu were populated via the ⁵²Cr+¹⁰O (65 MeV) reaction using the gamma detector array equipped with charged particle detector array for reaction channel separation. On the basis of γ-γ coincidence relations and angular distribution ratios, a level scheme was constructed up to E _n=7 MeV and J ^π=23/2⁽⁺⁾. The decay scheme deduced was interpreted in terms of shell model calculations, with a restricted basis of the f _5/2, p _3/2, p _1/2, g _9/2 orbitals outside a ⁵⁶ ₂₈Ni core.     

The B 2Σ+–X 2Σ+ Transition of 12C17O+: The 2‐υ″ Progression

Abstract

Three new bands of the B ²Σ⁺–X ²Σ⁺ system of ¹²C¹⁷O⁺ have been investigated using conventional spectroscopic techniques. The spectra were observed in a graphite hollow‐cathode lamp by discharging molecular oxygen (enriched in about 45% of the ¹⁷O₂ isotope) under 1.0 Torr pressure. The rotational analysis of the 2–4, 2–5, and 2–6 bands was performed with the effective Hamiltonian of Brown (Brown et al., J. Mol. Spectrosc. 1979; 74: 294–318). Molecular constants were derived from a merge calculation, including both the current wavenumbers and the spectroscopic data published by the authors previously. The principal equilibrium constants for the ground state of ¹²C¹⁷O⁺ are ω_e=2185.9658(84), ω_e x _e = 14.7674(11), B _e=1.927001(38), α_e=1.8236(22)×10^?2, γ_e=?0.331(28)×10^?4, D _e=6.041(12)×10^?6, β_e=0.100(31)×10^?7 cm^?1, and the equilibrium constants for the excited state are σ_e=45876.499(15), ω_e=1712.201(12), ω_e x _e=27.3528(39), B _e=1.754109(35), α_e=2.8706(57)×10^?2, γ_e = ?1.15(19)×10^?4, D _e=7.491(20)×10^?6, β_e=2.13(12)×10^?7, γ_e = 2.0953(97)×10^?2, and α_γe=?9.46(59)×10^?4 cm^?1, respectively. Rydberg–Klein–Rees potential energy curves were constructed for the B ²Σ⁺ and X ²Σ⁺ states of this molecule, and Franck–Condon factors were calculated for the vibrational bands of the B–X system.     

NQR, NMR and Crystal Structure Studies of [C(NH2)3]2HgX4 (X = Br, I)

The crystal structure of [C(NH₂)₃]₂HgBr₄ has been determined at room temperature: monoclinic, space group C2/c, with a = 10.035(2), b = 11.164(2), c = 13.358(3) Å, β = 111.67(3)°, and Z = 4. The crystal consists of planar [C(NH₂)₃]⁺ and distorted tetrahedral [HgBr₄]^2? ions. The Hg atom is located on a two-fold axis such that two sets of inequivalent Br atoms exist in an [HgBr₄]^2? ion. In accordance with the crystal structure, two ⁸¹Br NQR lines widely separated in frequency were observed between 77 and ca. 380 K. [C(NH₂)₃]₂HgI₄ yielded four ¹²⁷I NQR lines ascribable to m = ±1/2 ? ±3/2 transitions, indicating that its crystal structure is different from the bromide complex. The ¹H NMR T ₁ measurements showed a single minimum for the bromide but two minima for the iodide. The analyses based on the C₃ reorientations of the planar [C(NH₂)₃]⁺ ions gave the activation energies of 29.8 kJ mol^?1 for the bromide, and 30.2 and 40.0 kJ mol^?1 for the iodide.     

Luminescent characteristics of LiCaBo3:M (M=Eu, Sm, Tb, Ce, Dy) phosphor for white LED

LiCaBO₃:M (M=Eu³⁺, Sm³⁺, Tb³⁺, Ce³⁺, Dy³⁺) phosphors were synthesized by a normal solid-state reaction using CaCO₃, H₃BO₃, Li₂CO₃, Na₂CO₃, K₂CO₃, Eu₂O₃, Sm₂O₃, Tb₄O₇, CeO₂ and Dy₂O₃ as starting materials. The emission and excitation spectra were measured by a SHIMADZU RF-540 UV spectrophotometer. And the results show that these phosphors can be excited effectively by near-ultraviolet light-emitting diodes (UVLED), and emit red, green and blue light. Consequently, these phosphors are promising phosphors for white light-emitting diodes (LEDs). Under the condition of doping charge compensation Li⁺, Na⁺ and K⁺, the luminescence intensities of these phosphors were increased.     

Optoacoustic gas analyzer based on a13C16O2 laser for multicomponent pollution of air

A computer-aided optoacoustic gas analyzer based on a continuous¹³C¹⁶C₂ laser for multicomponent pollution of atmospheric air is described. The analyzer has the ability to detect absorption of radiation by detected substances at the level of ∼1·10⁻⁹ cm⁻¹ at a time resolution of 30 sec. Results of an experiment on simultaneous detection of H₂O, CO₂, NO₂, NH₃, HNO₃, OCS, and C₂H₄ in the atmospheric air using 40 laser lines are presented. B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 345–350, May–June, 1999.     

三角对称下3d3离子2E态g因子性质研究

采用完全对角化方法,以尖晶石结构的ZnAl₂Ｏ₄:Cr^3＋,ZnGa₂Ｏ₄:Cr^3＋和MgAl₂Ｏ₄:Cr^3＋系列晶体为例,联系晶格局域结构,对三角对称下3d³离子²E态g因子性质进行了研究.研究中考虑了包括自旋与自旋相互作用、自旋与另一轨 关键词： 2E态g因子')" href="#">²E态g因子 3离子')" href="#">3d³离子 尖晶石结构 磁相互作用     

Precise Nuclear Quadrupole Moments of 8B and 13B

The electric quadrupole coupling constants eqQ/h of ⁸B (, T _1/2 = 769 ms) and ¹³B (, T _1/2 = 17.4 ms) in single crystal TiO₂ have been precisely measured by the β-NQR technique. The ratios of these Q moments to Q(¹²B) were determined as ∣Q(⁸B)/Q(¹²B)∣ = 4.882(32) and ∣Q(¹³B)/Q(¹²B)∣ = 2.768(24).     

Upconversion luminescence of Tm^3＋/Yb^3＋ codoped oxyfluoride glasses

Novel oxyfluoride glasses are developed with the composition of 30SiO2-15Al2O3-28PbF2-22CdF2-0.1TmF3 - xYbF3 - （4.9 - x） AlF3（x=0, 0.5, 1.0, 1.5, 2.0） in tool fraction, Furthermore, the upconversion luminescence characteristics under a 970nm excitation are investigated. Intense blue, red and near infrared luminescences peaked at 453nm, 476nm, 647nm and 789nm, which correspond to the transitions of Tm^3＋： ^1D2 →^3F4, ^1G4 →^3H6, ^1G4 →^3F4, and ^3H4 →^3H6, respectively, are observed. Due to the sensitization of Yb^3＋ ions, all the upconversion luminescence intensities are enhanced considerably with Yb^3＋ concentration increasing. The upconversion mechanisms are discussed based on the energy matching rule and quadratic dependence on excitation power. The results indicate that the dominant mechanism is the excited state absorption for those upconversion emissions.     

The X2Π and A2Σ+ states of FH+, ClH+ and BrH+: theoretical study of their g -factors and fine/hyperfine structures

Theoretical calculations on the fine, hyperfine and Zeeman (g-factor) parameters are reported for the X²Π and A²Σ⁺ states of FH⁺, ClH⁺ and BrH⁺. The fine-structure constants [spin–orbit (A), Λ-doubling (p, q) and spin–rotation constants (γ _Π, γ _Σ)] are evaluated up to second order (via SO/L couplings with several excited states) using a multireference configuration interaction (MRCI) method, a Breit–Pauli Hamiltonian and 6-311++(2d,2pd) basis sets. Hyperfine constants of magnetic and electric type [Frosch–Foley (a, b, c, d) and nuclear quadrupole (eQq ₀, eQq ₂)] are studied with density functional methods and various basis sets. Magnetic dipole moments (parameterized via g-factors) are calculated in second order like the fine structure constants. The situation is somewhat complex for X²Π since no less than five different g’s have to be evaluated in second order. In general, our results are in good agreement with those reported in the literature, mostly limited to the ground state. Our calculations confirm that, at equilibrium, all second-order properties are dominated by the couplings between the electronic states X and A.     

Measurement of beam quality factor (M) by slit-scanning method

Beam quality factor (M²) and far-field scattering angle of LD end-pump Nd : YVO₄ laser were measured by slit-scanning method. The experimental results showed that the laser operated on a multi-mode state. The corresponding analytical treatments for slit-scanning method and M² factor measurement also were presented in this paper.     

立方对称晶场中6S(3d5)态离子的磁相互作用及其自旋哈密顿参量的微观起源

基于完全对角化方法(complete diagonalization method, CDM), 研究了⁶S(3d⁵)态离子在立方对称晶场中的磁相互作用,分析了自旋哈密顿参量(a, g,Δg)的微观起源.研究中除了考虑研究者通常考虑的SO(spin-orbit)磁相互作用外,同时考虑了SS(spin-spin),SOO(spin-other-orbit),OO(orbit-orbit)磁相互作用.研究表明：⁶S(3d⁵)态离子在立方对称晶场中的自旋哈密顿参量起源于五种机理,即SO机理,SS机理,SOO机理,OO机理以及SO-SS-SOO-OO联合作用机理.文中研究了五种机理的相对重要性,结果表明：SO机理与SO-SS-SOO-OO联合作用机理在五种机理中最为重要.尽管SS,SOO,OO磁相互作用单独作用时对自旋哈密顿参量的贡献很小,但它们的联合作用SO-SS-SOO-OO机理对自旋哈密顿参量的贡献非常可观.此外研究表明：零场分裂参量a主要来自纯自旋四重态及自旋二重态与自旋四重态联合作用的贡献,而Zeemang(或者Δg)因子主要来自纯自旋四重态的贡献.纯自旋二重态对自旋哈密顿参量a与g(或者Δg)的贡献为零.在我们所选择的晶场区域,发现下列关系始终成立：a>0,a(-|Dq|)<a(|Dq|),g(-Dq)=g(Dq),a(-Dq,-ξ_d,B,C)=a(Dq,ξ_d, B,C),Δg(-Dq,-ξ_d, B, C)=Δg(Dq,ξ_d, B, C).作为本文理论的应用,研究了四种典型的Mn²⁺掺杂晶体材料,即Mn²⁺:KZnF₃,Mn²⁺: RbCdF₃,Mn²⁺: MgO,Mn²⁺: CaO,理论与实验测量符合很好. 关键词： 自旋哈密顿参量 6S(3d⁵)态离子')" href="#">⁶S(3d⁵)态离子 磁相互作用 完全对角化方法(CDM)     

High-resolution infrared spectra of OOO ozone isotopomer in the range 900-5000 cm: line positions

Continuing the systematic study of ozone high-resolution infrared spectra, we present in this paper the measurements and analyses of line positions for the ¹⁸O¹⁶O¹⁸O isotopomer. In the range 900-5000 cm⁻¹, corresponding to the observed spectra, 15 bands are analysed: ν₁, ν₃, ν₂+ν₃, ν₁+ν₂, 2ν₃, ν₁+ν₃, 2ν₁, ν₂+2ν₃, ν₁+ν₂+ν₃, 3ν₃, 2ν₁+ν₃, ν₂+3ν₃, ν₁+3ν₃, ν₁+ν₂+3ν₃, and 5ν₃. As in the case of ¹⁶O₃, ¹⁸O₃, and ¹⁶O¹⁸O¹⁶O, the analysis of these bands is performed using effective rovibrational Hamiltonians for nine polyads of interacting upper vibrational states. To correctly reproduce all observed transitions, we have to account for resonance perturbations due to 13 “Dark” states: (0 3 0), (0 4 0), (2 1 0), (0 3 1), (1 0 2), (0 4 1), (1 1 2), (3 1 0), (0 3 2), (0 0 4), (3 2 0), (0 1 4), and (0 4 2). We present the range of observed transitions, the results for spectroscopic parameters (vibrational energy levels, rotational and centrifugal distortion constants, and resonance coupling parameters), as well as the statistics for rovibrational energy levels, calculations and measurements. A comparison of observed band centres with those predicted from an isotopically invariant potential function is discussed. The RMS deviation between predicted and directly observed band centres is ≈0.03 cm⁻¹ up to 3000 and ≈0.25 cm⁻¹ for all 16 bands up to 5000 cm⁻¹.     

The Influence on NMR Parameters of Silicon Penta Coordination in Silatranes

¹H, ¹³C, ¹⁹F and ²⁹Si NMR chemical shifts and coupling constants for Si-substituted silatranes, XSi(OCH₂CH₂)₃N, and triethoxysilanes, XSi(OCH₂CH₃)₃, where X = H, CH₃, and F have been studied. Expansion of the coordination numbers of silicon and tin leads to similar changes in the NMR parameters.     

The next-to-leading order (NLO) gluon distribution from DGLAP equation and the logarithmic derivatives of the proton structure functionF 2(x, Q 2) at lowx

At lowx, an analytic solution of the DGLAP equation for gluon in the next-to-leading order (NLO) is obtained by applying the method of characteristics. Its compatibility with double leading logarithmic approximation (DLLA) asymptotics is discussed and comparison with the exact ones like GRV98NLO is made. The solution is then utilized to calculate the derivatives∂F ₂ (x,Q ²)/∂ lnQ ² and ∂ lnF ₂(x,Q ²)/∂ ln (1/x) and compared with the recent HERA data. Our solution is found to reproduce most of the essential features of the data on the derivatives.     

LD抽运Er3+，Yb3+共掺磷酸盐玻璃被动调Q激光器的理论分析和数值计算

研究了以Co²⁺:MgAl₂O₄晶体为饱和吸收体的LD抽运Er³⁺,Yb³⁺共掺磷酸盐玻璃激光器.针对双掺离子之间的能量传递和Er³⁺的多种跃迁过程，结合Co²⁺:MgAl₂O₄晶体中Co²⁺离子的饱和吸收特性，给出了详尽的速率方程，在其基础上进行了数值分析，分析了输出镜透过率、激光介质长度、谐振腔长度、腔内往返损耗、饱和吸收体长度对激光阈值、峰值功率、单脉冲能量以及脉冲宽度的影响.     

The 2D {P} Spin-Echo-Difference Constant-Time [C, H]-HMQC Experiment for Simultaneous Determination of JH3′P and JC4′P in C-Labeled Nucleic Acids and Their Protein Complexes

A two-dimensional {³¹P} spin-echo-difference constant-time [¹³C, ¹H]-HMQC experiment (2D {³¹P}-sedct-[¹³C, ¹H]-HMQC) is introduced for measurements of ³J_C4′P and ³J_H3′P scalar couplings in large ¹³C-labeled nucleic acids and in DNA–protein complexes. This experiment makes use of the fact that ¹H–¹³C multiple-quantum coherences in macromolecules relax more slowly than the corresponding ¹³C single-quantum coherences. ³J_C4′P and ³J_H3′P are related via Karplus-type functions with the phosphodiester torsion angles β and ε, respectively, and their experimental assessment therefore contributes to further improved quality of NMR solution structures. Data are presented for a uniformly ¹³C, ¹⁵N-labeled 14-base-pair DNA duplex, both free in solution and in a 17-kDa protein–DNA complex.     

Isospin properties of () reactions for the formation of deeply-bound antikaonic nuclei

The formation of deeply-bound antikaonic nuclear states in nuclear (K⁻,N) reactions is investigated theoretically within a distorted-wave impulse approximation (DWIA), considering the isospin properties of the Fermi-averaged elementary amplitudes. We calculate the formation cross sections of the deeply-bound states by the (K⁻,N) reactions on the nuclear targets, ¹²C and ²⁸Si, at incident K⁻ lab momentum p_K⁻=1.0 GeV/c and θ_lab=0°, introducing a complex effective nucleon number N_eff for unstable bound states in the DWIA. The results show that the deeply-bound states can be populated dominantly by the (K⁻,n) reaction via the total isoscalar ΔT=0 transition owing to the isospin nature of the amplitudes, and that the cross sections described by ReN_eff and ArgN_eff enable to deduce the structure of the nuclear states; the calculated inclusive nucleon spectra for a deep -nucleus potential do not show distinct peak structure in the bound region. The few-body and states formed in (K⁻,N) reactions on s-shell nuclear targets, ³He, ³H and ⁴He, are also discussed.     

J Coupling between C and H across Hydrogen Bonds in Proteins

Two new two- or three-dimensional NMR methods for measuring ^3hJ_C′N and ^2hJ_C′H coupling constants across hydrogen bonds in proteins are presented. They are tailored to suit the size of the TROSY effect, i.e., the degree of interference between dipolar and chemical shift anisotropy relaxation mechanisms. The methods edit 2D or 3D spectra into two separate subspectra corresponding to the two possible spin states of the ¹H^N spin during evolution of ¹³CO coherences. This allows ^2hJ_C′H to be measured in an E.COSY-type way while ^3hJ_C′N can be measured in the so-called quantitative way provided a reference spectrum is also recorded. A demonstration of the new methods is shown for the ¹⁵N,¹³C-labeled protein chymotrypsin inhibitor 2.     

截断部分相干厄米-高斯光束的广义M2G因子

基于广义截断二阶矩法,推导出了截断部分相干厄米-高斯(H-G)光束的广义M²_G因子的解析表达式. 截断完全相干H-G光束、截断高斯谢尔模型(GSM)光束以及截断高斯光束可以做为本文结果的特例给出. 研究表明:截断部分相干H-G光束的广义M²_G因子与截断参数δ,模阶数m以及相干参数α有关. 当δ非常小时,M^{2关键词： 截断部分相干厄米高斯光束 M2_G因子')" href="#">广义M2_G因子 广义截断二阶矩法}     

HD+2，H+3和D+3与固体相互作用和三体尾流效应

从分子离子H⁺₃及其氘化同位素分子离子D⁺₃和HD⁺₂与超薄固体膜相互作用发生库仑爆炸为基础,分析讨论了H⁺₃,D⁺₃和HD⁺₂三种分子离子的形成机理,根据产物能谱分布,利用库仑爆炸技术确定了同位素分子离子HD⁺₂的结构形式,给出具体核间距数值.并确定在实验中不存在线状结构的HD⁺₂.提出一种三原子分子离子和固体相互作用中尾流效应的处理方式,通过和实验结果做比较发现这是一种非常理想的处理三体尾流效应的模式,并用之进一步确认了HD⁺₂的结构形状.文章对H⁺₃,D⁺₃和HD⁺₂三种分子离子的实验结果做了对比和讨论. 关键词： +₂')" href="#">微团簇HD⁺₂ +₃和D⁺₃')" href="#">H⁺₃和D⁺₃ 库仑爆炸 三体尾流势 团簇结构