Spin-triplet superconductivity in UNi(2)Al(3) revealed by the (27)Al Knight shift measurement

We report (27)Al Knight shift ( (27)K) measurement on a single-crystal UNi(2)Al(3) that reveals a coexistence of superconductivity and a spin-density-wave (SDW) type of magnetic ordering ( T(SDW) = 4.5 K). The spin part of (27)K, (27)K(s), does not change down to 50 mK across the superconducting (SC) transition temperature T(c) approximately 0.9 K. In contrast with the isostructural compound UPd(2)Al(3) ( T(c) approximately 2 K), which was identified to be a spin-singlet d-wave superconductor, the behavior of (27)K strongly supports that UNi(2)Al(3) , like UPt(3) and Sr(2)RuO(4), belongs to a class of spin-triplet SC pairing state superconductors.     

Ultraviolet upconversion fluorescence in rare-earth-ion-doped Y2O3 induced by infrared diode laser excitation

Room-temperature ultraviolet emission of Tm(3+) ions at 298 ((1)I(6)-->(3)H(6)), 364 ((1)D(2)-->(3)H(6)), and 391 nm ((1)I(6)-->(3)H(5)) was obtained in Y(2)O(3):Yb(3+)-Tm(3+) by continuous-wave diode laser excitation of 980 nm. Power dependence analysis demonstrates that five- and six-photon upconversion processes populate the (1)D(2) and (1)I(6) states, respectively. We believe that the (1)D(2) population originates from the cross relaxation (1)G(4)+(3)F(4)-->(3)H(4)+(1)D(2) of the Tm(3+) ions, while subsequent energy transfer from Yb(3+) to Tm(3+) excites the (1)D(2) state to the upper (1)I(6) state. High multiphoton-induced ultraviolet emission is also expected for other trivalent rare-earth ions similar to Tm(3+).     

Observation of time-dependent CP violation in B0 --> eta'K0 decays and improved measurements of CP asymmetries in B0 --> phiK0, KS0KS0KS0 and B0 --> J/psiK0 decays

We present improved measurements of CP-violation parameters in B(0) --> phiK(0), eta(')K(0), KS(0)KS(0)KS(0) decays based on a sample of 535 x 10(6) BB pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. We obtain sin2phi1(eff)=+0.64+/-0.10(stat)+/-0.04(syst) for B(0) --> eta(')K(0), +0.50+/-0.21(stat)+/-0.06(syst) for B(0) --> phiK(0), and +0.30+/-0.32(stat)+/-0.08(syst) for B(0) --> KS(0)KS(0)KS(0) decays. We have observed CP violation in the B(0) --> eta(')K(0) decay with a significance of 5.6 standard deviations. We also perform an improved measurement of CP asymmetries in B(0) --> J/psiK(0) decays and obtain sin2phi1=+0.642+/-0.031(stat)+/-0.017(syst).     

产生医用放射性核素核数据的测量、理论计算与评价

简要介绍已广泛用于临床的^32P,^89Sr,^90Y,^103Pd,^125I,^131I,^137Cs,^153Sm,^186Re,^188Re,^192Ir和具有很大潜在使用可能性的^64Cu,^67Cu,^67Ga,^86Y,^105Rh,^111In,^114mIn,^124I,^149Pm,^166Ho,^169Yb,^177Lu,^211At,^213Bi,^225Ac 26个放射性核素利用反应堆或加速器或衰变的55种不同途径产生的核数据的测量、理论计算及数据可靠性的初步评价,以改善其在诊断和治疗医用中的安全性、有效性和科学性。The nuclear data measurements and preliminary evaluation as well as alculation for established and emerging 26 radionuclides produced in 55 ways by using reactor or accelerator or decay are briefly introduced in order to keep the safety and validity in medical therapeutic applications. The 11 established radionuclides are ^32P,^89Sr,^90Y,^103Pd,^125I,^131I,^137Cs,^153Sm,^186Re,^188Re,^192Ir and the 15 emerging radionuclides are 64Cu,^67Cu,^67Ga,^86Y,^105Rh,^111In,^114mIn,^124I,^149Pm,^166Ho,^169Yb,^177Lu,^211At,^213Bi,^225Ac.     

First observation of the decays B(0) → D(+)K(-)π(+)π(-) and B(-) → D(0)K(-)π(+)π(-)

First observations of the Cabibbo-suppressed decays B(0) → D(+)K(-)π(+)π(-) and B(-) → D(0)K(-)π(+)π(-) are reported using 35 pb(-1) of data collected with the LHCb detector. Their branching fractions are measured with respect to the corresponding Cabibbo-favored decays, from which we obtain B(B(0) → D(+)K(-)π(+)π(-))/B(B(0) → D(+)π(-)π(+)π(-))=(5.9±1.1±0.5)×10(-2) and B(B(-) → D(0)K(-)π(+)π(-))/B(B(-) → D(0)π(-)π(+)π(-))=(9.4±1.3±0.9)×10(-2), where the uncertainties are statistical and systematic, respectively. The B(-) → D(0)K(-)π(+)π(-) decay is particularly interesting, as it can be used in a similar way to B(-) → D(0)K(-) to measure the Cabibbo-Kobayashi-Maskawa phase γ.     

Characterization of Electronic Spectra of Rhodium Monohydride and Monodeuteride

Emission spectra of two new electronic transitions of Pb(2) have been measured with a Fourier transform spectrometer in the 5200-8500 cm(-1) range. The emissions were observed from the afterglow of a microwave discharge in a mixture of Pb(x) vapor with hydrogen and argon carrier gas. By comparison with the results of ab initio calculations, the spectra are assigned to transitions from the lowest 1(g) and 1(u) states to the X(1)0(+)(g) ground state. The X(2)1(g) --> X(1)0(+)(g) transition between the fine-structure components of the X(3)Sigma(-)(g) ground state must be magnetic dipole in nature and thus is the first purely magnetic dipole fine-structure transition observed in the optical region. The 1(u) state is mostly a component of the low-lying inverted A(3)Pi(u) state and so is denoted A(2)1(u). Vibrational analyses have yielded the following electronic energies and vibrational constants for (208)Pb(2) (in cm(-1)): X(1)0(+)(g): omega(e) = 110.20(2), omega(e)x(e) = 0.341(2); X(2)1(g): T(e) = 5304.9(1), omega(e) = 120.57(7), omega(e)x(e) = 0.254(14); A(2)1(u): T(e) = 7817.5(2), omega(e) = 126.45(6), omega(e)x(e) = 0.399(11), where the numbers in parentheses are the standard deviations of the parameters. Copyright 2000 Academic Press.     

Evidence for B0 --> D+ D- and observation of B- --> D0D- and B- -->D0D*- decays

We report evidence for B(0) --> D(0)D(-) and the first observation of the decay modes B(-) --> D(0)D(-) and B(-) --> D(0)D(*-) based on a sample of 152 x 10(6) BB events collected by the Belle detector at KEKB. The branching fractions for B(0) --> D(+) D(-), B--->D(0)D(-), and B--> D(0)D(*-) are found to be (1.91 +/- 0.51 +/- 0.30) x10(-4), (4.83 +/- 0.78 +/- 0.58) x 10(-4), and (4.57 +/- 0.71 +/- 0.56) x 10(-4), respectively. Charge asymmetries in the B---> D(0)D(-) and B(-) --> D(0)D(*-) channels are consistent with zero.     

Observation of Upsilon(4S) decays to pi(+)pi(-)Upsilon(1S) and pi(+)pi(-)Upsilon(2S)

Observation of Upsilon(4S) decays to pi(+)pi(-)C and pi(+)pi(-)Upsilon(2S)We present the first measurement of Upsilon(4S) decays to pi(+)pi(-)Upsilon(1S) based on a sample of 230 x 106(4S) mesons collected with the BABAR detector. We measure the product branching fractions Beta(Upsilon(4S) --> pi(+)pi(-)Upsilon(1S)) x BetaUpsilon(1S) --> mu(+)mu(-) = (2.23 +/- 0.25(stat) +/- 0.27(syst))x 10(-6) and Beta(Upsilon(4S) --> pi(+)pi(-)Upsilon(2S) x Beta(Upsilon(2S) --> mu(+)mu(-))=(1.69 +/-0.26(stat) +/- 0.20(syst)) x 10(-)6, from which we derive the partial widths Gamma(Upsilon(4S) --> pi(+)pi(-)Upsilon(1S))=(1.8 +/-0.4) keV and Gamma(Upsilon(4S) --> pi(+)pi(-)Upsilon(2S))=(2.7 +/- 0.8) keV.     

Near-Infrared Laser Spectroscopy of TiS: The b(1)Pi-X(3)Delta Transition

Laser-induced fluorescence spectrum of TiS in the 769-863 nm region has been recorded and analyzed. The TiS molecule was produced using the technique of laser vaporization/reaction with supersonic cooling. Twenty-one weak subbands have been assigned as being due to b(1)Pi-X(3)Delta, B(3)Pi(0)-X(3)Delta(1), and C(3)Delta-X(3)Delta transitions. Strong evidence shows that the b(1)Pi state is responsible for perturbing the v = 0, 1, and 2 levels of the C(3)Delta(1) subband. The molecular constants of the b(1)Pi state have been determined as follows: T(e) = 10 589.47 cm(-1), omega(e) = 542.14 cm(-1), omega(e)x(e) = 3.16 cm(-1), B(e) = 0.19568 cm(-1), and alpha(e) = 0.00085 cm(-1). The spin-orbit interaction between the b(1)Pi (v = 2 and 3) and C(3)Delta (v = 1 and 2) levels is discussed in terms of configuration interaction occurring between the b(1)Pi from the 11varsigma(1) 5pi(1) configuration and the (1)Pi from the 5pi(1) 1delta(1) configuration, and the C(3)Delta state from 12varsigma(1) 1delta(1) configuration. Copyright 2000 Academic Press.     

Unambiguous identification of (17)O containing ozone isotopomers for symmetry selective detection

Symmetry selective detection of the (17)O containing ozone isotopomers (16)O(16)O(17)O and (16)O(17)O(16)O requires the unambiguous identification of absorption lines. We report high resolution tuneable diode laser spectrometer measurements of (17)O containing ozone isotopomers in the R-branch of the nu3 band and present a purely experimental technique that discriminates between (16)O(16)O(17)O and (16)O(17)O(16)O. Around 1040 cm(-1), differences in line positions of (16)O(17)O(16)O upto 4 x 10(-3) cm(-1) between our measurements and present spectroscopic database records (HITRAN 2004) are found.     

The High-Resolution FTIR Spectrum and Equilibrium Structure of Chloro(sulphido)boron

The FTIR spectrum of chloro(sulphido)boron, Cl-B&bond;S, has been recorded at 0.0035 cm(-1) resolution. The nu(3) bands of the isotopomers (35)Cl(11)B(32)S, (37)Cl(11)B(32)S, (35)Cl(11)B(34)S, (37)Cl(11)B(34)S, (35)Cl(10)B(32)S, (37)Cl(10)B(32)S, and (35)Cl(10)B(34)S have been analyzed to yield effective rotational and centrifugal distortion constants for the ground and a number of excited vibrational states. For the (35)Cl(11)B(32)S isotopomer the nu(1) band has also been analyzed. The rotational constants have been used to determine equilibrium bond lengths of 168.42(8) and 160.14(8) pm for the Cl-B and B-S bonds, respectively. Copyright 2000 Academic Press.     

Infrared Diode Laser Spectrum of the nu(1) Fundamental Band of ClBO

The nu(1) band of ClBO has been recorded using infrared diode laser spectroscopy. The molecule was produced by reacting oxygen atoms, produced in a microwave discharge containing an O(2)/He mixture, with BCl(3). Thirty-three lines of the (35)Cl(11)B(16)O isotopomer and 32 lines due to the (37)Cl(11)B(16)O isotopomer have been assigned. By fixing the ground state constants to those previously obtained by microwave spectroscopy, a least-squares fit (rms = 0.0008) gave the following upper state constants; (35)Cl(11)B(16)O: nu(0) = 1972.18024(21) cm(-1), B(1) = 0.1725055(12) cm(-1); (37)Cl(11)B(16)O: nu(0) = 1971.82846(24) cm(-1), B(1) = 0.1688402(13) cm(-1). The rotational constants of all the fundamental bands of ClBO have been used to calculate an r(e) structure yielding r(e(B-Cl)) = 167.668(26) pm and r(e(B-O)) = 121.308(26) pm. Copyright 2000 Academic Press.     

Measurement of (1)J(NC') and (2)J(H(N))(C') couplings from spin-state-selective two-dimensional correlation spectrum.

A method for the measurement of (1)J(NC') and (2)J(H(N))(C') coupling constants from a simplified two-dimensional [(15)N, (1)H] correlation spectrum is presented. The multiplet components of the (1)J(NC') doublet in the indirect dimension and (2)J(H(N))(C') in the direct dimension are separated into two subspectra by spin-state-selective filters. Thus each subspectrum contains no more peaks than the conventional [(15)N, (1)H]-HSQC spectrum. Furthermore, the method for the measurement of (1)J(NC') and (2)J(H(N))(C') is designed to exploit destructive relaxation interference (TROSY). The results are verified against the measurements of (1)J(NC') from spin-state-selective [(13)C', (1)H] correlation spectra recorded with additional sequence described here.     

Determination of backbone angle psi in proteins using a TROSY-based alpha/beta-HN(CO)CA-J experiment

Transverse relaxation-optimized NMR experiment (TROSY) for the measurement of three-bond scalar coupling constant between (1)H(alpha)(i-1) and (15)N(i) defining the dihedral angle psi is described. The triple-spin-state-selective experiment allows measurement of (3)J(H(alpha)N) from (13)C(alpha), (15)N, and (1)H(N) correlation spectra H(2)O with minimum resonance overlap. Transverse relaxation of (13)C(alpha) spin is minimized by using spin-state-selective filtering and by acquiring a signal longer in (15)N-dimension in a manner of semi-constant-time TROSY evolution. The (3)J(H(alpha))(N) values obtained with the proposed alpha/beta-HN(CO)CA-J TROSY scheme are in good agreement with the values measured earlier from ubiquitin in D(2)O using the HCACO[N] experiment.     

C_(60)O_n(n=2,3)异构体的合成和理论计算研究

本文通过臭氧氧化C60得到C60On的混合物,反相高压液相色谱图表明有两种C60O2异构体和两种C60O3异构体,分别标记为C60O2(I)、C60O2(II)和C60O3(I)、C60O3(II),同时得到了它们的UV-vis谱图。为了确定它们的最可能结构,我们对四种最可能的C60O2异构体和九种最可能的C60O3异构体进行了理论计算,从能量、偶极矩、电子光谱方面进行了系统研究,提出了实验得到的C60On(n=2,3)的稳定结构。计算结果与实验吻合良好。     

Millimeter-Wave Spectroscopy of Sulfur Dichloride

The rotational spectra of (32)S(35)Cl(2), (32)S(35)Cl(37)Cl, (32)S(37)Cl(2), and (34)S(35)Cl(2) in their ground vibrational states, as well as those of (32)S(35)Cl(2) and (32)S(35)Cl(37)Cl in their nu(2) and 2nu(2) excited states, have been studied in selected frequency regions between 100 and 370 GHz. Transitions involving a large range of quantum numbers have been observed, so that precise rotational and quartic centrifugal distortion constants could be determined for each of the spectra investigated. The complete set of sextic distortion constants was also obtained for the most abundant isotopomer in its ground vibrational state. The newly determined rotational constants of (34)S(35)Cl(2) and (32)S(37)Cl(2) allowed us to calculate the complete r(s) structure of sulfur dichloride using both single- and double-isotopic substitution methods. The quadratic force field has been refined using a larger set of quartic distortion constants and inertial defects. Copyright 2000 Academic Press.     

Resonant spin excitation in an overdoped high temperature superconductor

An inelastic neutron scattering study of overdoped Bi(2)Sr(2)CaCu(2)O(8+delta) ( T(c) = 83 K) has revealed a resonant spin excitation in the superconducting state. The mode energy is E(res) = 38.0 meV, significantly lower than in optimally doped Bi(2)Sr(2)CaCu(2)O(8+delta) ( T(c) = 91 K, E(res) = 42.4 meV). This observation, which indicates a constant ratio E(res)/k(B)T(c) approximately 5.4, helps resolve a long-standing controversy about the origin of the resonant spin excitation in high temperature superconductors.     

Noncritically phase-matched frequency conversion in Gd(x)Y(1-x)Ca(4)O(BO(3))(3) crystal

A nonlinear optical crystal YCa(4)O(BO(3))(3) (YCOB) is phase matchable for third-harmonic generation (THG) of a Nd:YAG laser by type I mixing between 1.064 and 0.532mum . By partial substitution of Gd for Y in YCOB, a solid solution Gd(x)Y(1-x)Ca(4)O(BO(3))(3) gradually changes the phase-matching angles of THG to (theta, ?)=(90( degrees ), 90 ( degrees )) . We present the properties of noncritically phase-matched THG in Gd(x) Y(1-x)Ca(4)O(BO(3))(3) (x=0.28) .     

BaMgAl10O17:Eu2+,Mn2+中Eu2+→Mn2+的能量传递

在还原气氛下采用高温固相法合成了BaMgAl10O17:Mn2 ,BaMgAl10O17:Eu2 ,BaMgAl10O17:Eu2 ,Mn2 粉末样品,测量并研究了它们的激发光谱和发射光谱性质.结果表明:BaMgAl10O17:Eu2 ,Mn2 中,Eu2 的发射光谱和Mn2 的吸收光谱之间的光谱交叠范围较大,两种离子之间发生了明显的交叉弛豫过程,即有较强的共振能量传递过程,导致在紫外光的激发下,样品BaMgAl10O17:Eu2 ,Mn2 发射光谱中以蓝光和绿光为主.     

Rovibrational Intensities of the (00(0)3) <-- (10(0)0) Dyad Absorption Bands of (12)C(16)O(2)

Absolute line intensities of (12)C(16)O(2) are experimentally measured for the first time for the (00(0)3)(I) <-- (10(0)0)(II) band at 5687.17 cm(-1) and the (00(0)3)(I) <-- (10(0)0)(I) band at 5584.39 cm(-1). The spectra were obtained using a Bomem DA8 Fourier transform spectrometer and a 25-m base-path White cell at NASA-Ames Research Center. The rotationless bandstrengths at a temperature of 296 K and the Herman-Wallis parameters are S(0)(vib) = 6.68(30) x 10(-25) cm(-1)/(molecule/cm(2)); A(1) = 1.4(9) x 10(-4), and A(2) = -1.1(5) x 10(-5) for the (00(0)3)(I) <-- (10(0)0)(II) band and S(0)(vib) = 6.07(22) x 10(-25) cm(-1)/(molecule/cm(2)); A(1) = 5.2(1.5) x 10(-4) and A(2) = -4.0(7) x 10(-5) for the (00(0)3)(I) <-- (10(0)0)(I) band.