Der Zerfall des122Xe (T 1/2=20,l h) und des122J (T 1/2=3,6min)

Theγ spectra emitted in the decay of¹²²Xe and¹²²I have been investigated using Ge(Li) detectors and a Ge(Li)-NaI coincidence apparatus. 14γ transitions with energies between 61.8 and 416.9 keV have been identified in the decay of¹²²Xe, 44 transitions between 564.0 and 3,291.0 keV in the decay of¹²²I. Level schemes having 7 excited levels for¹²²I and 21 excited levels for¹²²Te are proposed.     

Der zerfall des J121 (T 1/2=2,12 h)

I¹²¹ was produced by bombarding a target of enriched Te¹²² with deuterons of 25 MeV. Theγ rays associated with the decay of I¹²¹ have been investigated using a Ge(Li) detector and a Ge(Li)-NaI coincidence set up. 58γ transitions ranging from 212.5 to 1841.8 keV have been identified. A decay scheme for the I¹²¹→Te¹²¹ decay which accounts for 50 of the observedγ transitions is proposed.     

Nuclear orientation study of the decay of208At (T 1/2=1.63 h) and209At (T 1/2=5.41 h) implanted in iron host

We have measured the angular distribution of gamma-rays in 208,209Po following the decay of the mass-separated isotopes 208,209At polarized at low temperatures in an iron host. Multipole mixing ratios were deduced for 14 and 9 gamma-ray transitions in 208Po and 209Po, respectively, and unambiguous spin-assignments were made for several levels in both nuclei.     

μ+ shift study inCdMgx (x=1%, 2%, 2.5%)shift study inCdMgx (x=1%, 2%, 2.5%)

In continuation of our earlier studies of the anomalous temperature dependence of the μ⁺ Knight shift K_μ in Cd,CdHg (1.2 at %) andCdMg (3.38 at %) — interpreted as due to Van Hove-type singularities in the local density of electron states /1/ — we have studied the temperature dependence of the μ⁺ Knight shift in polycrystallineCdMg (1.04 at %, 2.05 at %) and in a single crystal ofCdMg (2.5 at %). In contrast to pure Cd no anisotropies in K_μ could be detected. The temperature dependence of K_μ in aCdMg (2.05 at %) sample and in the monocrystallineCdMg (2.5 at %) sample essentially reproduces the one previously observed in polycrystallineCdMg (3.38 at %), showing a steplike discontinuity and a logarithmic singularity. A complete different behaviour is observed inCdMg (1.04 at %), where no logarithmic singularity seems to show up and where a steplike discontinuity of opposite sign at around 90 K is clearly seen. If these singularities are still to be interpreted in terms of Van Hove singularities, the question arises why there is such a nonlinear dependence on the Mg concentration.     

The alpha decay study of223Th (T 1/2=0.6 s)

Correlations between neutrons have been studied in the 96 MeV¹⁸O +⁶⁴Ni reaction, yielding the compound nucleus⁸²Kr at 88 MeV excitation energy. The observed anticorrelation at small relative momenta evidences dominance of quantum-statistical interference between identical particles, from which it is possible to deduce an average source lifetimeτ=(1.2±0.1)·10^?20 s as an upper limit disregarding possible contributions to the correlation function from the competingnn final-state interaction. Lacking appropriate model calculations at present, it is argued that further refinements in the theoretical treatment of strong interactions in the final state are needed to enable truly quantitative conclusions from small-angle nucleon-nucleon correlations at such large timescales.     

Methanol photomineralization in a Xe2 photoreactor (λ = 172 nm) with aeration of a solution

It is demonstrated that mineralization of methanol in a water solution in a Xe₂* photoreactor (λ ∼ 172 nm) upon exposure to vacuum ultraviolet radiation with aeration allows the process to be to intensified and the exposure time to be reduced by several times. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 95–97, October, 2006.     

Bestimmung des (631)K=1/2, I=1/2-Zustandes im U 239

Theγ-ray spectrometer at the DR 3-reactor at Risø was used to investigate the low energyγ-lines of U 239 which are emitted during neutron-capture in U 238. Very closely lying lines have been found between 500 and 650 keV. The big intensity of the 133 keV line and the lack of other transitions of appropriate energy and intensity point out that this line corresponds to the hinderedE 2-transition from the (631)I=1/2⁺ level to the (622)I=5/2⁺ groundstate. A suggestion was made for the decay possibility of the octupole states at 700 keV found by N.Fiebiger.     

Measurement of the nuclear magnetic moment of110Ag(T 1/2=24.4 s)

Nuclear magnetic resonance of¹¹⁰Ag has been observed in silver halides using the polarized neutron capture,β decay anisotropy method. The magnetic moment was determined asμ _I(¹¹⁰Ag)=2.7084 (5) nm (uncorrected).     

Electric quadrupole moments of the K π = 8− and 23/2− isomeric states in 170, 171, 172Hf

The spectroscopic quadrupole moments of the K ^π = 8^? isomers in ¹⁷⁰Hf and ¹⁷²Hf, Q _s ?=?4.91(17) b and 5.40(19) b, respectively and Q _s ?=?4.92(17) b for K ^π ?=?23/2^? in ¹⁷¹Hf have been measured using the time differential perturbed angular distribution technique. The nuclear reaction ¹⁶⁰Gd(¹⁶O, xnγ) was used to excite the respective isomeric states and for the recoil implantation of Hf nuclei into the Hf foil. The quadrupole deformation for the 8^? isomer and the ground state has the same value. The deformation corresponding to 23/2^? isomeric state is observed to be reduced with respect to the ground state due to the i _13/2 neutron alignment. The results are in good agreement with the multi-quasiparticle calculations.     

The H(2)(18)O solvent-induced isotope shift in (19)F NMR

The H(2)(16)O/H(2)(18)O solvent-induced isotope shifts ((18)O SIIS) of the (19)F NMR signals of a number of fluorine compounds have been measured. These isotope shifts are observed to be upfield, downfield, or zero, depending on the specific compound and the precise solution conditions. At 25 degrees C and with an (18)O enrichment of 86%, the (18)O SIIS of several fluorinated amino acids were in the range of 0.0014-0.0018 ppm downfield. 5-Fluorouridine displays a significantly wider range of (18)O SIIS values. A 5-fluorouridine-labeled 16-mer RNA also displayed observable (18)O SIIS values, but the characteristics of these were significantly modified from those of free 5-fluorouridine. The experimental observations are consistent with the (18)O SIIS being composed of upfield and downfield components, with the relative contributions of these determining the size and direction of the overall isotope shift. This is discussed in terms of a combination of van der Waals interactions between the fluorine atom and the solvent, electrical and hydrogen bonding effects, and the perturbations to these due to (18)O substitution in the solvent water. This isotope effect promises to be a highly useful tool in a range of (19)F NMR studies.     

193T1超形变带K=1/2的可能性

分析了脱耦合项对于原子核转动惯量的重要影响.总结了奇质量核K=1/2带转动惯量变化规律的新特点.在此基础上讨论了¹⁹³T1中3条新的超形变带的内部结构.目前尚无足够证据能够确认它们都是K=1/2带.     

Precise measurement of magnetic moment of short-lived β-emitting nuclei 12B (Iπ= 1+, T1/2 = 20.18 ms)

The spin polarized β-emitting nuclei 12B (Iπ = 1+, T1/2 = 20.18 ms) were produced by the nuclear reaction 11B(d, p) 12B and by the selection technique of the incident deuteron energy and the 12B recoil angle following the nuclear reaction. The nuclear magnetic moment of the short-lived nuclei 12B was measured by β-NMR with the β-NMR and β-NQR setup established for the first time in China. The nuclear magnetic moment of 12B was determined to be μ = 0.99993 ± 0.00048 nm or g = 0.99993 ± 0.00048 after the precise correction of the Knight shift.     

Twists in Hopf algebras andRT 1 T 2=T 2 T 1 relations

LetR be a matrix unitary quasi-classical solution of the Yang-Baxter equation. Considering an associative algebra defined by the relationRT ₁ T ₂=T ₂ T ₁ we find a universal twistF such thatR is the image ofR=F ₂₁ F ⁻¹ in the vector representation. Presented at the 11th Colloquium “Quantum Groups and Integrable Systems”, Prague, 20–22 June 2002.     

Theoretical Study of the Collision-Induced Double Transition CO(2) (nu(3) = 1) + N(2) (nu(1) = 1) <-- CO(2) (nu(3) = 0) + N(2) (nu(1) = 0) at 296 K

A procedure is presented for the calculation of the double vibrational collision-induced absorption CO(2) (nu(3) = 1) + N(2) (nu(1) = 1) <-- CO(2) (nu(3) = 0) + N(2) (nu(1) = 0) on the basis of quantum lineshapes computed using an isotropic potential and dipole-induced dipole functions. The linestrengths and energies of the vibration-rotation transitions are treated explicitly for N(2), utilizing the HITRAN database for CO(2). The theoretical absorption profile is compared to recent experimental results. By narrowing the width of the individual lines contributing to the overall absorption profile relative to their values determined for N(2)-N(2) collision-induced absorption, excellent agreement between theory and experiment is obtained. Copyright 2000 Academic Press.     

Al2O3X(X=H,D, T)的电子振动近似理论方法研究

用密度泛函理论(DFT)方法在6-311++G(d,p)水平上对Al₂O₃X(X=H, D, T)分子较低能量的几何构型进行了优化. 计算结果表明该分子有两个可能基态, 即Al₂O₃X(X=H,D,T)(²A′)C_s和Al₂O₃X 关键词： 2O₃X(X=H;D;T)分子团簇')" href="#">Al₂O₃X(X=H;D;T)分子团簇 热力学函数 氢同位素效应 吉布斯自由能改变     

The PMC processes associated to the (1/2, 1/2)-Bernoulli shift are also Bernoulli

It is proven that the Prigogine-Misra-Courbage (PMC) processes associated to the (1/2, 1/2)-Bernoulli shift are Bernoulli shifts. The Bernoulli partitions are constructed explicitly by using the decomposition of the transition kernels of the PMC processes on the fibers of the stable manifold of the transformed point (the generating property of these partitions is proved for any two-symbol Bernoulli shifts).     

s~(1/2)=355GeV附近的R值测量

利用北京谱仪 (BES)在s=3.5 5GeV附近获取的总积分亮度约为 5 pb-1的实验数据 ,测量了e e-湮没强子产生截面与 μ子对产生截面的比值 (即R值 ) .其测量误差比其它实验组已发表的此能区的测量误差减小约 5 0 % .     

导出E=mc~2和m=m_0/(1-v~2/c~2)~(1/2)的一种方案

借助光子导出了E=mc2和m=m01-v2/c2.