International Nuclear Information System (INIS)

Nucleon decay of underbarrier one-quasiparticle states with large angular momentum in soft spherical nuclei is considered. It is shown that energy dependences of differential probabilities of nucleon decay to the ground (0"+) and first excited (2"+) states of daughter nucleus differ qualitatively from each other due to strong interaction between quasiparticles and low-lying quadrupole states.

International Nuclear Information System (INIS)

K"#pi#=20"- and 49/2"- yrast isomers have been discovered in "1"7"6Ta and "1"7"7Ta, with meanlives of 1.4 ms and 0.19 ms, respectively. The long meanlives arise from substantial K-hindrance in the "1"7"6Ta case but from spin-trapping in the "1"7"7Ta case. Quasiparticle calculations, which treat the Fermi and pairing energies self-consistently, reproduce the excitation energies of these isomers and the other multi-quasiparticle high-K states observed. Due to blocking, pairing is significantly reduced in the 3-quasiparticle states, the extent depending on the specific configurations. It is completely quenched for both protons and neutrons in the highest seniority states. Yrast traps of even higher spin are predicted to exist in "1"7"6Ta and "1"7"7Ta. ((orig.)).

International Nuclear Information System (INIS)

The electron scattering form factor for excitation of the 1"+ state of "8"8Sr at 3.486 MeV has been calculated in the quasiparticle random phase approximation (QRPA). The disagreement between the data and restricted shell-model calculations can be explained in terms of the pairing correlations introduced by the QRPA; no #DELTA#-h admixtures are required. (orig.).

International Nuclear Information System (INIS)

By using a model dielectric matrix in electron self-energy evaluations the computational effort of a quasiparticle band-structure calculation for a semiconductor is greatly reduced. Applications to various systems with or without inversion symmetry, having narrow or wide band gaps, and semiconductor alloys demonstrate the reliability and accuracy of the method. Calculations have been performed for thirteen semiconducting or insulating materials: Si, LiCl, AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, InSb, and the Al_0_._5Ga_0_._5As and In_0_._5_3Ga_0_._4_7As alloys. Excellent agreement with experimental results is obtained for the quasiparticle energies for these materials. The only three exceptions, E(#GAMMA#_1_c) of AlP, E(L_1_c) of AlAs, and E(L_1_c) of AlSb are discussed and attributed to various experimental uncertainties. Several other quasiparticle-excitation-related properties are also examined in this work. The ...

International Nuclear Information System (INIS)

The high-spin states in transitional odd-mass nuclei are studied in terms of an odd quasi-particle coupled to an asymmetric rotor with a variable moment of inertia (VMI). In order to take into account the VMI, the basis states are expanded in terms of the core eigenfunctions. Excitation energies, quadrupole moments, magnetic moments, B(E2) values and B(M1) values are calculated and compared with the experimental data for nuclei in Au and La regions. On comparison with other descriptions it is found that the treatment with VMI provides a more satisfactory explanation of the data. (Auth.).

International Nuclear Information System (INIS)

Isomers have been populated in "2"4"6Cm and "2"5"2No with quantum numbers K"#pi#=8"-, which decay through K"#pi#=2"- rotational bands built on octupole vibrational states. For N=150 isotones with (even) atomic number Z=94-102, the K"#pi#=8"- and 2"- states have remarkably stable energies, indicating neutron excitations. An exception is a singular minimum in the 2"- energy at Z=98, due to the additional role of proton configurations. The nearly constant energies, in isotones spanning an 18% increase in Coulomb energy near the Coulomb limit, provide a test for theory. The two-quasiparticle K"#pi#=8"- energies are described with single-particle energies given by the Woods-Saxon potential and the K"#pi#=2"- vibrational energies by quasiparticle random-phase approximation calculations. Ramifications for self-consistent mean-field theory are discussed.

International Nuclear Information System (INIS)

The high-spin structure of the Z=77 nucleus "1"8"7Ir has been studied using the fusion-evaporation reaction "1"8"6W("7Li6n) at a beam energy of 59 MeV. The excitation scheme of this nucleus has been extended by more than 110 new states, including extensions of all previously established rotational bands. The band crossing region of the h_9_/_2 negative-parity yrast band has been revised and new intrinsic high-K states have been identified. In particular, a 29/2"- isomeric state [T_1_/_2=1.8(5)#mu#s] at an excitation energy of 2487 keV has been observed for the first time, and on top of it, a rich level scheme reaching up to spin (59/2"-) and excitation energies around 7 MeV has been established.

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The Green's function method in the Quasiparticle Time Blocking Approximation is applied to nuclear excitations in {sup 132}Sn and {sup 208}Pb. The calculations are performed self-consistently using a Skyrme interaction. The method combines the conventional RPA with an exact single-particle continuum treatment and considers in a consistent way the particle-phonon coupling. We reproduce not only the experimental values of low-and high-lying collective states but we also obtain fair agreement with the data of non-collective low-lying states that are strongly influenced by the particle-phonon coupling. (orig.)

International Nuclear Information System (INIS)

I present results for the mass spectrum of excited baryons and pentaquarks using overlap fermions and Bayesian curve-fitting method; and magnetic moments and polarizabilities for a variety of hadrons in the background field method.

International Nuclear Information System (INIS)

An apparatus allowing the photoexcitation of barium atomic beam over its whole surface is described. This photoexcitation is achieved by another barium spectrum emitted up steam of the beam by a cathodic out-flow produced at the exit oven. The fluorescence spectrum is studied in detail as well as the influence of different parameters, such as oven temperature, current intensity of the outflow, and excitation depth. A calculation shows how to determine Einstein coefficient, oscillator strengths and atomic lifetimes from our experimental measurements.

International Nuclear Information System (INIS)

The method of augmented plane wave (APW) is used to obtain the band structure of the SmS compound in the semiconductor and metal phases. The noncentral part of the Coulomb electron-electron interaction is taken into account in the first order perturbation theory. In this case the radial part of the wave APW-function is taken as a zero approximation function. A multiplet structure of the excited configuration f"5d, which provides a good description of the X-ray photoelectron spectrum and optical spectrum epsilon_2(#omega#), is obtained. The configuration fd is calculated for the interpretation of the optical absorption spectrum of the samarium monosulfide metal phase. (author).

International Nuclear Information System (INIS)

The modular and periodic antenna structure in TCA is shown to produce an extremely pure spectrum of excited waves. This purity, together with precise measurements of the antenna loading in different parts of the spectrum, has allowed us to demonstrate that it is essential to include both toroidal coupling and the Hall effect (#omega#/#omega#/sub c//sub i/not =0) in order to explain our results. We show that toroidicity produces coupling from the directly excited Vertical BarmVertical Bar = 1 wave to Vertical BarmVertical Bar = 0,2 waves. Discrete Alfven Waves are also seen for Vertical BarmVertical Bar = 0,2 in addition to the directly driven Vertical BarmVertical Bar = 1. The importance of the Hall effect is most visible when a travelling wave is excited, in which case the antenna loading depends on the direction of the wave imposed. We present the antenna loading found with ...

CERN Document Server

We present first worldline numerical results for the nontrivial interplay between geometry and temperature dependencies of the Casimir effect. We show that the temperature dependence of the Casimir force can be significantly larger for open geometries (e.g., perpendicular plates) than for closed geometries (e.g., parallel plates). For surface separations in the experimentally relevant range, the thermal correction for the perpendicular-plates configuration exhibits a stronger parameter dependence and exceeds that for parallel plates by more than an order of magnitude at room temperature. This effect can be attributed to the fact that the fluctuation spectrum for closed geometries is gapped, inhibiting the thermal excitation of modes at low temperatures. By contrast, open geometries support a thermal excitation of the low-lying modes in the gapless spectrum already at low temperatures.

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It is shown that pure NQR can be utilized as a platform for quantum computing without applying a high external magnetic field. By exciting each resonance transition between quadrupole energy levels with two radio-frequency fields differing in phase and direction, the double degeneracy of the spin energy spectrum in an electric field gradient is removed. As an example, in the case of I=7/2 (nuclei {sup 133}Cs or {sup 123}Sb) the energy spectrum has eight levels which can be used as three qubits. (orig.)

International Nuclear Information System (INIS)

... transitions lutetium 175 target mev range 10-100 multipolarity neutrons parity

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A theoretical study of an exciton confined in a quantum ring is presented. The quantum ring is described as a two-dimensional circular quantum dot with a repulsive core, which is modelled with the help of two Gaussian functions. We have applied the variational method and investigated the evolution of the low-energy exciton spectrum with the change of the confinement potential. The calculations have been performed for the recently produced self-assembled ring-shaped InGaAs quantum dots. We have shown that the repulsive core strongly increases the radiative transition probability from the exciton ground state at the expense of the decreasing probability of the transitions from the excited states. This effect results from the orthogonality properties of the exciton wavefunctions, which are specific to the quantum-ring confinement potential. We have studied the characteristic features of the exciton spectrum, which can be used ...

International Nuclear Information System (INIS)

The results of experimental researches of photoluminescence and X-ray luminescence in crystal ZnSe are presented at the different values of tension of electric-field to samples. Observed, that the electric field changes both intensity of stationary luminescence and form of bars in the spectrums of luminescence. At the saliatory change of difference of potentials on the electrodes of crystal in luminescence there are of long duration relaxation processes character of which substantially depends on the type of excitation of standard.

International Nuclear Information System (INIS)

Low fluorescence in the field of the Eu3+ photoluminescence spectrum is registered against a bach ground of the continuum of solvent emanation when multi-bubble sonolysis of EuCl3 (0.1 mol l-1) solutions saturated by the air and argon in heavy water. Distinctive sonoluminescence of europium ion is not found earlier in aqueous solutions. Possible reasons of low values of Eu3+ sonoluminescence as compared with other lanthanide ions (Ln3+), and effect of europium on the spectrum of solvent continuum connected, in particular, with the quenching of electron-excited products of the H2O* (O2O*) and Eu3+* sonolysis in the reactions of electron transfer are discussed

International Nuclear Information System (INIS)

Reduction of the metallic impurity concentration in the TCA plasma has enabled us to correlate the observed heating with the calculated position where the rf energy is deposited. In modelling the measured antenna loading due to the presence of Alfven resonance surfaces, and hence inferring the energy deposition profile, both ion cyclotron effects and the toroidal geometry must be considered. In particular, toroidicity couples energy to resonance surfaces that would not be excited in cylindrical geometry. The increase in electron density during a rf pulse changes the positions of these surfaces so that spectrum-related effects may be observed. The appearance of a new surface at the centre of the plasma is seen as a sharp discontinuity on many of the macroscopic parameters, accompanied by evidence of changes in the current density profile. These results, and the predictions of numerical codes, have imposed new constraints on the optimisation of ...

CERN Document Server

Jet-driven shocks are responsible for an important fraction of the emission of the narrow-line regions (NLRs) in many classes of AGN. However, this cannot explain all observations. It is clear that the remaining sources are photoionised by the active nucleus. The 2-d hydrodynamic models from the RSAA group support an evolutionary scenario whereby the shock-excited NLRs are initially jet-driven but later, ionizing photons from the central engine replace shocks as the main excitation mechanism and shock induced star formation may also become important. In their photoionized phase, dusty and radiation-pressure dominated evolution produces a self-regulated NLR spectrum. This model aso explains the coronal emission lines and fast (3000 km s$^{-1}$) outflows seen in some Seyferts.

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We have developed a low-temperature particle detector that uses a novel quasiparticle trapping mechanism to funnel athermal phonon energy from an 80 mg Ge absorber into a 1.6 mg doped Ge thermistor via a superconducting Al film. We report on pulse height spectra obtained at 320 mK by scanning a {sup 241}Am alpha source along the device, and show that up to 20% of the energy deposited in the Ge absorber by a 5.5 MeV alpha particle interaction can be collected into a thermistor via quasiparticle trapping. We show that this device is sensitive to the position of an alpha particle interaction in the Ge absorber for interaction distances of up to 5 mm from a quasiparticle trap.

International Nuclear Information System (INIS)

Electronic circular dichroism (ECD) of the n-#pi# and #pi# -#pi# transitions of the amide groups in the ultraviolet has become an indispensable tool for qualitative characterization of proteins in solution. Since the existence of such a spectrum (that is, of natural optical activity) comes from the three dimensional interaction of the chromophores in the molecule, CD is exquisitely sensitive to molecular conformation. However, in proteins, the amide transitions available in the near UV are limited in number and are broads and overlapping. Interactions among them yield information about the polymeric backbone, but since such amide electronic excitation are relatively delocalized, the resulting

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There are two non-equivalent sites of yttrium in the lattice of Y{sub 2}SiO{sub 5}. Both of them may be occupied substitutionally by Er{sup 3+}, resulting in a laser active material. We measured absorption spectra of Y{sub 2}SiO{sub 5}:Er{sup 3+} at several low temperatures and we studied its emission spectrum at 4.2 K following selective excitation of individual Stark components of the {sup 4}I{sub 13}2/ to {sup 4}I{sub 15}2/ transition by the light of a tunable colour centre laser. The results of these two experiments allow classification of the absorption and emission lines into two independent systems, thus yielding two energy level schemes 1 and 2. Moreover, simple crystal field calculations strongly suggest from which Y{sub 2}SiO{sub 5} crystallographic site spectrum 1 arises, and from which one spectrum 2. (author)

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The authors present a search for excited and exotic muon states {mu}*, conducted using an integrated luminosity of 371 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV at the Tevatron with the CDF II detector. They search for associated production of {mu}{mu}* followed by the decay {mu}* {yields} {mu}{gamma}, resulting in the {mu}{mu}{gamma} final state. They compare the data to model predictions as a function of the mass of the excited muon M{sub {mu}*}, the compositeness energy scale {Lambda}, and the gauge coupling factor f. No signal above the standard model expectation is observed in the {mu}{gamma} mass spectrum. In the contact interaction model, they exclude 107 < M{sub {mu}*} < 853 GeV/c{sup 2} for {Lambda} = M{sub {mu}*}; in the gauge-mediated model, they exclude 100 < M{sub {mu}*} < 410 GeV/c{sup 2} for f/{Lambda} = 10{sup -2} GeV{sup -1}. These 95% ...

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The ..beta.. decay half-lives of neutron-rich isotopes with Z=24-28 are calculated in the QRPA with a Gamow-Teller residual interaction. For odd-mass and odd-odd systems QRPA phonon correlations are introduced to quasiparticle transitions in first-order perturbation. The calculated half-lives agree very well with the experimental values. For later application of this model to nuclei far from stability, we have examined the dependence of the calculated half-lives on the model parameters.

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Pairing correlations in multi-quasiparticle states in deformed nuclei are expected to be reduced because of blocking. New intrinsic states and their associated rotational bands have been identified allowing comparisons to be made as a function of seniority and between nuclei. The possible effects of the reduced pairing on the collective rotation, and its manifestation in terms of alignment, are discussed. 13 refs., 2 figs.

International Nuclear Information System (INIS)

An experimental investigation was made of the #gamma#-transitions feeding or de-exciting the 1355 keV isomeric state in "1"7"7Ta. The E2/M1 mixing ratios for the 311 keV interband transition from the isomer and for the 271 keV and the 295 keV intraband transitions within the rotational band on the isomer were determined to be delta = 0.29sup(+0.11)sub(-0.06), 0.25sup(+0.05)sub(-0.03) and 0.30sup(+0.06)sub(-0.08), respectively, employing combined measurements of the linear polarization and angular distribution of the #gamma#-ray with the aid of conversion electron measurements. Spin and parity assignments of the isomer were confirmed to be 21/2"-. The half-life of the isomer was remeasured to be Tsub(1/2) = 5.0 +- 0.2 #mu#s and the magnetic moment was found to be #mu# = 0.080 +- 0.014 #mu#sub(N). The gsub(K) and gsub(R) factors for the band on the isomer were deduced separately to be gsub(K=21/2"-) = 0.062sup(+0.011)sub(-0.008) and gsub(R) = ...

International Nuclear Information System (INIS)

A new high-sensitivity wide-bandwidth 1.25-5.5 eV (225-1000 nm) spectrometer has been constructed to measure luminescence emission spectra of minerals that are of interest for optical dating. Spectra of emission resulting from 1.43 eV (IR) excitation after #gamma#-irradiation are reported for 13 cut rock feldspars and 20 feldspar separates. Also reported are phosphorescence spectra following #gamma#-irradiation, and after 1.4 eV excitation. The main differences between the infrared stimulated luminescence spectra and the phosphorescence is the almost complete absence of the violet, 3.1 eV, and yellow-green, 2.2 eV, bands in the phosphorescence, and the presence of a green emission band centred at 2.7 eV in the phosphorescence following #gamma#-irradiation (but absent in the phosphorescence following 1.4 eV excitation). The red, 1.7 eV, band is present in all the phosphorescence spectra but is not always seen during 1.4 eV ...

International Nuclear Information System (INIS)

Tris(8-quinolinolato)aluminum(III) (Alq3) shows electronic absorption bands at 378, 360 (in a 1:1 mixed solvent of methanol and ethanol (ME) at 77 K), 334, 316, 300, 263, 255.8, and 233 nm in ethanol at room temperature. According to the polarized fluorescence excitation spectrum together with MO calculations, for instance, the 360 nm band is assigned to an LL CT transition (an intramolecular charge transfer transition between two ligands), and the 378 nm band to an LM/ML CT one (an intramolecular charge transfer transition between ligand and metal). Alq3 shows a broad fluorescence band peaking at around 478 nm in the ME matrix at 77 K. The emission spectrum measured with a phosphoroscope has two emission bands at 567 and 478 nm. The 567 nm band accompanies vibronic bands at 578 and 605 nm, being safely assigned to a phosphorescence of Alq3. The lifetimes of the 478 and 567 nm bands are both 5.4 ms. The lifetime of the 478 ...

International Nuclear Information System (INIS)

The fundamental optical properties of dysprosium (Dy) doped strontium sulfide bulk samples for various dopant concentrations from 0.1 to 1.0 at.% were investigated by X-ray diffraction (XRD), electron paramagnetic resonance spectroscopy (EPR), room temperature photoluminescence (PL), photoluminescence excitation (PLE) and diffuse reflectance spectroscopy (DRS). Investigations by electron paramagnetic resonance yielded the state of Dy in the sample as Dy3+. An additional ESR line due to F+ center was observed. The PL emission spectrum consisted of several intense lines and a number of weaker ones which were identified as transitions between energy levels of Dy3+. The optimum doping concentration for maximum intensity was found to be 0.25 at.%. Blue shift of the absorption edge energy and red shift of the PLE spectrum were observed with increasing doping concentration. The former is due to Burstein-Moss (BM) effect and the ...

International Nuclear Information System (INIS)

Russian 1987. p. 452. USSR Dao Tien Kkhoa Knyaz'kov, OM Kukhtina,

Energy Technology Data Exchange (ETDEWEB)

The infrared spectrum of the rotovibrational band {ital v}=0{r_arrow}2 of parahydrogen has been observed in the condensed phases down to {ital T}=2 K. In the solid, phonon and roton sidebands exhibit peaks corresponding to those observed in the fundamental. Contributions arising from the reorientation of ortho-H{sub 2} impurities have been detected. The {ital Q}{sub 1}(0)+{ital S}{sub 1}(0) band has been resolved into an asymmetric doublet, and the origin of this latter is discussed. In the liquid phase the observed line shapes include strong translational contributions, and are accounted for by assuming that at short times the excited molecule is encapsulated in the cage of nearest neighbors.

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The linearized collective Schroedinger equation for nuclear quadrupole surface vibrations incorporates a new spin degree of freeedom with a spin value of 3/2. We use this equation to describe the low energy spectrum of certain even-odd Ir nuclei which have a spin 3/2 in their ground state. For that purpose we explicitly introduce collective spin-dependent potentials which simulate the interaction of the valence nucleon with the core. The linearized Schroedinger equation is transformed into an effective Schroedinger equation with collective spin-dependent potentials. Already collective spin-orbit couplings of SO(3) and SO(5) type are sufficient to reproduce the lowest excited states of even-odd Ir nuclei. (orig.).

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The photoluminescence intensity of an optical emitter changes when placed in close proximity to a noble-metal nanoparticle, due to two contributions. First, the optical near-field of the nanoparticle leads to a change in excitation rate of the emitter. Secondly, the emission efficiency is changed due to an optical energy transfer from the emitter to the metal nanoparticle, which provides additional radiative and non-radiative decay channels. In this work we investigate the photoluminescence of Sm{sup 3+} ions, which are embedded in SiO{sub 2}. The photoluminescence spectrum of ions in proximity to single silver and gold nanoparticles is measured. The influence of the spectral position of the nanoparticle plasmon peak on the photoluminescence yield will be discussed and compared with model calculations.

International Nuclear Information System (INIS)

A new formulation of meson self-energies is introduced for #sigma#,#omega#,#pi#,#rho#,#delta#, and #eta# mesons on the basis of the particle-hole-antiparticle representation. We have studied the difference between the meson self-energy (MSE) of this representation and the MSE of the traditional density-Feynman (DF) representation. It is shown that the new formulation describes exactly the physical processes such as particle-hole excitations or particle-antiparticle excitations, and that, on the other hand, the meson self-energy based on the DF representation includes unphysical components. By numerical calculations, the meson self-energies describing the particle-hole excitations are shown to be close to each other for most of the meson self-energy in low momentum (R<500 MeV) and low energy (R_0<200 MeV). This fact implies that former calculations using the low momentum and low-energy part do not change greatly. The ...

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Conference excitement recalled by "CERN courier" report

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The first overtone spectrum of solid parahydrogen with various low ortho impurity levels has been studied in detail using a White-type external multireflection system. For the Q{sub 2{l_arrow}0}(0) transition the authors have observed the fully resolved threefold splitting due to the crystal field effect. Furthermore, the authors have obtained a rich satellite spectrum associated with the transitions Q{sub 2{l_arrow}0}(0) and Q{sub 2{l_arrow}0}(1) at different ortho-H{sub 2} contents revealing information about the ortho-H{sub 2} pair interaction in the second vibrationally excited state of the hydrogen molecule. A preliminary analysis and assignment of these satellite transitions will be presented. Another point of study was the spectral region around 8300 cm{sup -1}, where the double transitions of the type Q{sub 1{l_arrow}0}(n) + Q{sub 1{l_arrow}0}(n{prime}) (n, n{prime} = 0,1) are located. The most remarkable features ...

Science.gov (United States)

Low-frequency current noise and current-voltage (I-V) characteristics have been studied in InAs/GaAs self-assembled Quantum Dot Infrared Photodetectors in dark conditions and under illumination, at T = 77K and T = 5K. The noise behavior is consistent with a generation-recombination fluctuation process mainly related to thermally excited charge carriers at T = 77K. At T = 5K the current noise is consistent with a mechanism of fluctuations driven by the electric field, related to tunneling rather than emission-capture of charge carriers from the Quantum Dots. A very effective noise suppression mechanism, related to the tunneling regime, determines a decrease of fluctuation intensity as a function of the voltage. At T = 5K, an interesting behavior is observed in the current-voltage and noise power spectra for some of nominally identical QDIP structures in the presence of irradiation. Some devices indeed exhibit (i) a very high photoresponse and (ii) a 1/f-shaped noise ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Visible blue cathodoluminescence (CL), photoluminescence (PL), x-ray excited optical luminescence (XEOL) and electroluminescence (EL) via Zf free excitonic emission have been obtained from CuBr thin films deposited on glass, Cr coated glass, GaAs and Si substrates. In addition to the Zf emission several peaks corresponding to Cu+ emissions via 3d94s - d10 transitions were observed on the AC EL spectrum at 2.10, 2.7, 3.03, 3.07 and 3.80 eV. X-ray diffraction (XRD) measurements confirmed that the vacuum evaporated CuBr thin films grow preferentially with a (111) orientation irrespective of the substrate. While the AC voltage source was found to have no detrimental effects on CuBr thin films, cathodic deposition of Cu metal via electrolytic decomposition was observed under steady sta...

International Nuclear Information System (INIS)

The energy levels of the configuration f"2 in an eight-fold cubic crystal field (CF) have been calculated, and the results are used to explain the experimental spectrum of UO_2. The fourth-order CF potential turns out to be much smaller than usually assumed for this compound. This has an effect of reducing the J-mixing in the wavefunctions, particularly in the case of the ground state wavefunction. In spite of the strength of the CF, the ground state vertical stroke "3H_4T_2 right angle is found to be modified only slightly by the J-mixing effect; it consists of 89.4% "3He_4, and the remaining eleven components make up the rest. Very good correlation is obtained between the experimental and simulated energy-level schemes. The predominance of "3H_4 in the ground state consequently increases the value of the calculated effective magnetic moment. The results are compared with our previous predictions about the system, and relevant conclusions drawn in the light of ...

International Nuclear Information System (INIS)

A phenomenological simulation was carried out for 41 experimental crystal-field (CF) levels within the "4I_9_/_2_-_1_5_/_2, "4F_3_/_2_-_9_/_2, "4S_3_/_2 and "2H_9_/_2 J manifolds, including the available infrared (IR) data up to #approx#15 000 cm"-"1 for the Nd"3"+ ions in the Nd_2CuO_4 single crystals. The CF Hamiltonian for the tetragonal C_4_v symmetry was diagonalized together with the free-ion Hamiltonian in a basis that spans the entire 4f"3 configuration. A rms error of 9 cm"-"1 between the calculated and experimental energy level schemes was obtained. A comparison of the spectra in the visible region between the insulating Nd_2CuO_4 and the metallic Nd_2_-_xCe_xCuO_4, allowed identifying the absorption bands associated with the development of the charge-doping induced local structural distortions in the superconducting regime.

British Library Electronic Table of Contents (United Kingdom)

The alloying effects on K to L shell vacancy transfer probabilities (?KL) in 3d transition metals have been carried out by X-ray fluorescence studies of various alloy compositions. K X-ray intensity ratios of Ti, Cr, Fe, Co, Ni, and Cu elements in the FexNi1?x, FexCr1?x, NixCr1?x, FexCryNi1?(x+y), TixNi1?x, TixCo1?x, and CoxCu1?x alloys have been measured following excitation by 22.69keV X-rays from a 10 mCi 109Cd radioactive point source and ?KL values for alloying elements have been determined from these ratios. The spectrum of characteristic K-X-ray photons from samples were detected with a high resolution Si(Li) detector coupled to a 4 K multichannel analyzer. The present investigation makes it possible to ...

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No abstract prepared.

International Nuclear Information System (INIS)

... excitation experimental data gamma radiation mev range 01-10 parity

International Nuclear Information System (INIS)

According to the calculations, intensity of the KL_1L_2("3P_0) Auger transition should drastically increase with increasing atomic number Z due to the relativistic effects. However, this behavior was experimentally proved only for very few elements. A lack of enough precise experimental data in the atomic number region Z<45 does not enable one to distinguish between relativistic and non-relativistic approaches in this region. Thus for Z=38 the KL_1L_2("3P_0/"1P_1) intensity ratio was determined with relative uncertainty of 63 % in the only measurement with external excitation. Here we present results of our investigation of the KLL Auger electron spectrum of "8"8Sr generated in the EC decay of "8"8Y (T_1_/_2= 106.6 d). Electron spectra were measured with the 11 eV instrumental resolution using a combined electrostatic spectrometer. The present value of the KL_2L_3("1D_2) absolute transition energy in Sr is higher by 7.4 eV (i.e. more than ...

International Nuclear Information System (INIS)

We present sensitive high angular resolution (0.''57-0.''78) SO, SO_2, CO, C_2H_5OH, HC_3N, and HCOCH_2OH line observations at millimeter and submillimeter wavelengths of the young O-type protostar W51 North made with the Submillimeter Array. We report the presence of a large (about 8000 AU) and hot molecular circumstellar disk around this object, which connects the inner dusty disk with the molecular ring or toroid reported recently and confirms the existence of a single bipolar outflow emanating from this object. The molecular emission from the large disk is observed in layers with the transitions characterized by high excitation temperatures in their lower energy states (up to 1512 K) being concentrated closer to the central massive protostar. The molecular emission from those transitions with low or moderate excitation temperatures is found in the outermost parts of the disk and exhibits an inner cavity with an angular size of around 0.''7. ...

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The nuclear shapes of transitional Mo isotopes are calculated by means of a model based on the cranking approximation and the Strutinksy method. The recent experimental results of the high-spin spectroscopy and lifetime measurement of [sup 87]Mo are studied in detail and explained by the evolution of the [gamma]-deformation with the quasiparticle configurations. The shape calculations with the modified-harmonic-oscillator potential give a critical neutron number N [>=] 47 for the spherical shape of the Mo isotopes. (orig.)

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Experimentally it is found that at constant temperature the order-parameter relaxation time, tausub(..delta..), decreases with increasing power of the microwaves, coupled into a superconducting strip. If the same increase in critical current, that corresponds with a given power of the microwaves, is obtained by lowering the temperature, the decrease in tausub(..delta..) is smaller. This reflects the fact that quasiparticles are removed more efficiently from the gap edge by microwaves than by lowering the temperature in equilibrium. A modified time-dependent Ginzburg-Landau equation is shown to describe these results adequately.

International Nuclear Information System (INIS)

Spectral-luminescent characteristics of Sr2Y8(SiO4)6O2: Eu powder crystal phosphor with the apatite structure and high-intensity luminescence of Eu3+ ions have been studied. The charge state of europium in the samples has been characterized by means of X-ray L3-adsorption spectroscopy. It was established that Eu3+ forms two types of optical centers. Besides, luminescence of Eu2+ions was found. Reduction Eu3+#->#Eu2+ was considered, which may be due to VSr|| vacancy formation in the 4f crystal lattice position and to negative charge transfer by this vacancy to two EuY3+ ions. Thus, in the silicate lattice there exist inhomogeneously distributed oxygen-deficient centers, which are responsible for nonradiative transfer of excitation energy to Eu3+ and Eu2+ ions. To study electron-vibrational interactions in the crystal phosphor samples, their IR and Raman spectra were examined. In the luminescence spectrum of Eu2+, a series of low-intensity ...

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A method to identify hadronic molecules in the particle spectrum is reviewed and the conditions for its applicability discussed. Special emphasis is put on the discussion of molecule candidates in the baryon spectrum. (orig.)

Science.gov (United States)

... switching off all the pixels causes all the spectrum lines to disappear (top of Figure 6), next, that switching off one ... Acousto-optic spectrum analyser ...

Energy Technology Data Exchange (ETDEWEB)

Nuclei in the mass-180 region have many high-{Omega} single-particle levels close to the Fermi energy and are, therefore, prime candidates for high-K isomers. Since both neutron and proton level densities are rather low, one should expect blocking and particle-number fluctuations to be rather important. We have performed good-particle-number calculations and have shown that the simpler blocked BCS theory gives a good approximation to the multi-quasiparticle spectra if the pairing strength is chosen appropriately. This has allowed us to perform a systematic theoretical study of this mass region. Residual spin-spin interactions are shown to be essential in reproducing the energies and even the correct order of known states. Good agreement has been found for {sup 175}Hf, {sup 176}Hf and {sup 177}Ta, where extensive data already exist. Predictions for new high-K states near the yrast line are made for these nuclei and for {sup 178}W. (orig.).

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Bremstrahlung Isochromat Spectroscopy (BIS). The XES spectra were collected using a Specs electron gun for the excitation and the XES 350 grating monochromator and channel plate system from Scienta as the photon detection. Spectra were collected in 'normal mode,' where the electron gun kinetic energy (KE) and the energy position of the center of the channel plate were both fixed and the energy distribution in the photon (hv) spectrum was derived from the intensities distributed across the channel plate detector in the energy dispersal direction. The polycrystalline Ce sample was oxidized by exposure to air at ambient pressures. After introduction to the ultra-high vacuum system, the oxidized sample was bombarded with Ar, to clean the topmost surface region and stabilize the surface and near surface regions. Although CeO{sub 2} would be the thermodynamically preferred composition in an oxygen rich environment, the combination ...

International Nuclear Information System (INIS)

... coriolis force de-excitation excited states half-life iridium 187 multipolarity

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The schematic model is extended to open-shell nuclei. The quasiparticle random-phase approximation plus core polarization are used to calculate multipole matrix elements M/sub n/ and M/sub p/. Calculated trends in the ratio of deformation parameters ..beta../sub n//..beta../sub p/ are compared with experimental ratios for several sets of isotopes and isotones. The systematics indicate a rather abrupt change toward equality of ..beta../sub n/ and ..beta../sub p/ when N or Z is changed from a closed-shell value.

International Nuclear Information System (INIS)

Energy level schemes are derived from gamma spectroscopy of several medium-mass deformed nuclei by studying the decay or proton and #alpha# nuclear spectroscopic data. Some new isomeric studies are established among which is the 31 y "1"7"8Hf isomeric state for which Isup(#pi#), K was determined to be 16"+, 16. A four quasi-particle configuration was assigned to this state at 2447.5 +- 2.5 KeV. Atomic masses have been calculated from various measurements and, on the basis of mass formulae extrapolated to neighboring mass regions.

International Nuclear Information System (INIS)

The crystal structure, electronic structure, and photoluminescence properties of EuxSi6-zAlz-xOz+xN8-z-x (x=0-0.1, 0xMySi6-zAlz-x-yOz+x+yN8-z-x-y (M=2Li, Mg, Ca, Sr, Ba) have been studied. Single-phase EuxSi6-zAlz-xOz+xN8-z-x can be obtained in very narrow ranges of x?0.06 (z=0.15) and z2+ ions can be incorporated into nitrogen-rich Si6-zAlzOzN8-z. The Eu2+ ion is found to occupy the 2b site in a hexagonal unit cell (P63/m) and directly connected by six adjacent nitrogen/oxygen atoms ranging 2.4850-2.5089 A. The calculated host band gaps by the relativistic DV-X? method are about 5.55 and 5.45 eV (without Eu2+ 4f5d levels) for x=0 and 0.013 in EuxSi6-zAlz-xOz+xN8-z-x (z=0.15), in which the top of the 5d orbitals overlap with the Si-3s3p and N-2p orbitals within the bottom of the conduction band of the host. EuxSi6-zAlz-xOz+xN8-z-x shows a strong green emission with a broad Eu2+ band centered at about 530 nm under UV to near-UV excitation range. The ...

International Nuclear Information System (INIS)

... beta spectrometers decay energy-level transitions k conversion l conversion

KoreaScience (Korea)

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International Nuclear Information System (INIS)

Eu-#alpha#-SiAlON (Eu_m_/_2Si_1_2_-_m_-_nAl_m_+_nO_nN_1_6_-_n) was synthesized with nominal compositions having small m and n values, by firing the powder mixture of Eu_2Si_5N_8, #alpha#-Si_3N_4, AlN, and Al_2O_3 at 1900 "oC for 6 h under 1 MPa nitrogen atmosphere. The ratio of the oxidation state of Eu"2"+/Eu"3"+ was estimated from the X-ray absorption fine structure (XAFS) measurement. The observed X-ray absorption near edge spectrum (XANES) showed that the Eu ion in Eu-#alpha#-SiAlON was mainly in divalent state but also coexisted with a small amount of Eu in the trivalent state. The crystal structure of Eu-#alpha#-SiAlON was refined by the Rietveld analysis of the X-ray powder diffraction patterns. The lattice constants of the samples increased with increasing m and n values. The excitation band of Eu-#alpha#-SiAlON ranged from the ultraviolet to the visible light region and a broad emission band centered at about 590 nm were observed. The ...

International Nuclear Information System (INIS)

Oxyfluoride aluminosilicate glasses in the composition of 50SiO2-20Al2O3-20LiF-10GdF3-0.5TmF3-xYbF3 (x = 0, 1.0, 2.5, 5, 7.5, 10, 15, 20, 25 and 30 mol%) have been prepared to study their thermal and optical properties. From the differential thermal analysis measurements, glass transition temperatures and onset crystallization temperatures have been evaluated and from them glass stability factors were calculated. Glass stabilities decreased gradually with fluoride content increment in all the studied glasses. The photoluminescence and decay measurements have also been carried out for all these glasses. In these glasses, an efficient near infrared quantum cutting with optimal quantum efficiency approaching 187% has been demonstrated, by exploring the co-operative downconversion mechanism from Tm3+ to Yb3+, with 467 nm (Tm3+ : 3H6 ? 1G4) excitation wavelength. These glasses are promising materials to achieve high efficiency silicon based solar cells by means of ...

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No abstract prepared.

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Energy Technology Data Exchange (ETDEWEB)

Calculations of total and angle-differential excitation cross sections for the electron impact excitation of lithium-like iron were performed with the R-matrix formulation. The alignments of the excited states 1s{sup 2}np {sup 2}P{sub 3/2} are also presented for n=3 and 4 along with the angular photon distribution from these states to the ground state. Relativistic effects were included in the present calculations by the Breit-Pauli Hamiltonian.

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No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Experience with the identification and tuning of exciter constants for a generating unit as the Second Nuclear Power Plant of Taiwan Power Company is reported. Field test is first performed on the excitation system with the generator open-circuited. Since the field test results differ from the computer simulation results using manufacturer`s constants, the authors first modify the manufacturer`s constants based on their previous experience to reach a preliminary set of parameters for the excitation system. Then a hybrid nonlinear simulation-sensitivity matrix method is developed to further refine the excitation system parameters. The exciter constants are tuned in order to give better dynamic response before a power system stabilizer is applied to the generator. Field tests are then performed in order to compare the dynamic response of the generator without and with power system ...

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Measurements of {gamma}-ray, {gamma}{gamma}-coincidence and internal conversion electron spectra from the {sup 106}Cd({alpha},n{gamma}){sup 109}Sn reaction were carried out at 15-20 MeV {alpha}-particle bombarding energies with Ge(HP) {gamma}-ray and superconducting magnetic lens plus Si(Li) electron spectrometers. The energies, relative intensities, internal conversion coefficients and coincidence relations of the {sup 109}Sn transitions were determined, and a more complete, consistent level scheme has been deduced. Spin and parity values have been determined from the internal conversion coefficients, the bombarding-energy dependence of the side-feeding intensities of the states and the available {gamma}-ray angular distribution data. The level scheme was interpreted in the framework of the quasi-particle shell model.

International Nuclear Information System (INIS)

The band crossing in "1"3"2Ba has been investigated by using the interacting boson model. A broken neutron pair has been coupled to a collective boson core. The boson-fermion interaction hamiltonian contains terms which can transform a boson into a pair of quasiparticles and vice versa. The parameters were partly determined by fitting the collective states of "1"3"2","1"3"4Ba and the yrast states of "1"3"1Ba. The energy backbending has been satisfactorily reproduced. Good agreement of the electromagnetic moments has been reached. The structure of the wave functions has been discussed. (author)

Energy Technology Data Exchange (ETDEWEB)

Formulas are obtained for calculation of the energies and B(Elambda) values of T/sub greater-than/ giant resonances in the quasiparticle-phonon model of the nucleus. Characteristics of giant dipole resonances are calculated in several spherical nuclei and the correct location is obtained for T/sub less-than/ and T/sub greater-than/ collective 1/sup -/ states. The calculated ratios sigma/sub -/1(T/sub greater-than/)/sigma/sub -/1(T/sub less-than/) agree with the experimental data for /sup 88/Sr, /sup 90/Zr, and /sup 92/Mo and are 3 times larger than the experimental values for /sup 116,120,124/Sn. The decrease of the cross sections sigma/sub -/1(T/sub greater-than/) in /sup 124/Sn in comparison with /sup 116/Sn is correctly reproduced.

International Nuclear Information System (INIS)

The use of chemically selective laser ionization combined with #beta# -delayed neutron counting at CERN/ISOLDE has permitted identification and half-life measurements for 623-ms "6"1Mn up through 14-ms "6"9Mn . The measured half-lives are found to be significantly longer near N=40 than the values calculated with a quasiparticle random-phase-approximation shell model. Gamma-ray singles and coincidence spectroscopy has been performed for "6"4","6"6Mn decays to levels of "6"4","6"6Fe , revealing a significant drop in the energy of the first 2"+ state in these nuclides that suggests an unanticipated increase in collectivity near N=40 . copyright 1999 The American Physical Society.

UK PubMed Central (United Kingdom)

CTX-M-25 is a novel extended-spectrum β-lactamase isolated from a single Canadian Escherichia coli isolate. Susceptibility testing demonstrated that this enzyme confers resistance...Full Text Available

UK PubMed Central (United Kingdom)

CTX-M extended-spectrum β-lactamases (ESBLs) are increasingly prevalent worldwide among Escherichia coli bacteria, mostly in community-acquired urinary tract infections. Finding...Full Text Available

UK PubMed Central (United Kingdom)

Among 149 extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae isolates collected from patients in southeast Austria from 1998 to 2004, 38 Escherichia coli...Full Text Available

UK PubMed Central (United Kingdom)

A nationwide survey of extended-spectrum β-lactamase (ESBL) production among Enterobacteriaceae, carried out in 2003, showed that CTX-M-type enzymes have achieved a sizeable...Full Text Available

International Nuclear Information System (INIS)

(Jun 1978). United States Miller, H. Univ. of Missouri, Columbia Peterman,

Energy Technology Data Exchange (ETDEWEB)

Secondary deuterium in the atmosphere are produced in interactions by primary cosmic rays. The shape of their energy spectrum depends on the primary cosmic ray spectrum incident at the top of the atmosphere. At high energies, the spectral shape depends on the primary spectrum of helium and heavy nuclei. However, at very low energies, specially below the geomagnetic cut-off, the spectral shape depends on the evaporation and recoil processes and hence almost independent of the spectral shape of the primary radiation. It is undertaken a calculation of the secondary deuterium spectrum at small atmospheric depths at various latitudes and the results will be presented.

Science.gov (United States)

... In 1982 an acousto-optic spectrum analyzer incorporated ... the OPTIMP is the optically controlled optical ... switch that changes the intensity reflectance ...

International Nuclear Information System (INIS)

... reactions differential cross sections dwba excitation excited states mev range

UK PubMed Central (United Kingdom)

Cells have an internal compass that enables them to move along shallow chemical gradients. As amoeboid cells migrate, signaling events such as Ras and PI3K activation occur spontaneously on pseudopodia....Full Text Available

Science.gov (United States)

Available from UMI in association with The British Library. Requires signed TDF. Design of time and correlation windows for non -parametric frequency response estimates. The thesis deals with problems that arise in the field of spectral analysis due to finite observations of input and output records. In particular, it is concerned with the method of applying time and correlation windows in spectral analysis procedures to obtain non-parametric frequency response estimates of open-loop time invariant systems. The thesis reviews and develops the sources of error that arise when frequency response techniques are applied directly to windowed records of input and output data to estimate the frequency response of open loop systems. Having identified the cause of these errors, methods of eliminating or reducing them are studied. The techniques introduced involve the use of differing time windows for the input and output data records. It is shown that windows can be designed on the basis of ...

Energy Technology Data Exchange (ETDEWEB)

Er{sub 3}NbO{sub 7} phosphor was synthesized by sintering a mixture of Er{sub 2}O{sub 3} and Nb{sub 2}O{sub 5} powder in a molar ratio of 3:1 at 1600 deg. C over 55 h. Optical absorption and emission characteristics of Er{sup 3+} ions in the calcined Er{sub 3}NbO{sub 7} powder were investigated and discussed compared with ErNbO{sub 4} phosphor and a Z-cut congruent Er (2 mol%):LiNbO{sub 3} single crystal. The absorption and emission studies show that, due to different crystal structures, the spectroscopic properties of these niobates have some differences in spectral shape, peak position, and relative intensity, especially at 1.5 {mu}m. The most obvious spectral feature of the Er{sub 3}NbO{sub 7} is that the spectral structure of band instead of peak is observed in its absorption or emission spectrum due to the existence of local structural disorder and multiple Er{sup 3+} sites. The Er{sub 3}NbO{sub 4} shows stronger upconversion emission than the single crystal ...

Science.gov (United States)

Attention is given to recent research on gear fault diagnostic techniques. A mathematic model for vibration signals of defective gears is presented. Novel methods of gear fault diagnosis, such as zoom complex envelope analysis, wideband demodulation techniques, bispectrum analysis, correlation spectrum analysis, and maximum entropy spectrum analysis, are demonstrated. The wide-band demodulation technique is found to exhibit a high SNR. Bispectrum and correlation spectrum are excellent for some mechanical fault forms.

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... capture radioisotopes energy levels excited states intermediate mass nuclei

International Nuclear Information System (INIS)

... electron reactions electrons excitation inelastic scattering m1-transitions proton

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This exciting new development in neutron star evolution was presented at the Winter 2004 AAS Meeting in Atlantia,Georgia. ...

International Nuclear Information System (INIS)

... mixing coupled channel theory differential cross sections excited states helium

International Nuclear Information System (INIS)

... coincidence spectrometry decay excited states gamma spectra half-life

Energy Technology Data Exchange (ETDEWEB)

We discuss the search of excited leptons and quarks with spin 1/2 at {gamma}{gamma} and at {gamma}e colliders. We show that {gamma}{gamma} colliders have important advantages for the observation of excited leptons and quarks in comparison with ee, ep, and pp colliders discussed in previous papers. These collisions give a simple test for the chirality of the l{sup *}l{gamma} transition. The anomalous magnetic moment of excited leptons can be observed when its value is not too small. (orig.).

Science.gov (United States)

The progress in the development of a surface analysis tool based on the excitation of characteristic

Energy Technology Data Exchange (ETDEWEB)

The author shows in this paper an interesting relation between elementary and topological excitations in the antiferromagnetic and d-wave superconducting phases of the t-J model at two dimensions. The topological spin and charge excitations in one phase have the same dynamics as elementary excitations in the other phase, except the appearance of energy gaps. Moreover, the transition from one phase to another can be described as a quantum disordering transition associated with the topological excitations. Based on the above picture, a plausible phase diagram of t-J model is constructed.

International Nuclear Information System (INIS)

... RADIATION PHYSICS beta decay delayed protons excited states experimental

International Nuclear Information System (INIS)

Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-color, two-step resonant scheme was used to selectively ionize the desorbed Ir atoms. The hyperfine structure (HFS) and isotope shift (IS) of the first transition of the ionization path 5d"76s"2"4F_9_/_2#->#5d"76s6p"6F_1_1_/_2 at 351.5nm were measured for "1"8"2"-"1"8"9Ir, "1"8"6Ir"m and the stable "1"9"1","1"9"3Ir. The nuclear magnetic moments #mu#_I and the spectroscopic quadrupole moments Q_s were obtained from the HFS spectra and the change of the mean square charge radii from the IS measurements. The sign of #mu#_I was experimentally determined for the first time for the masses 182#=#+0.2 for the lighter group A=186g, 185, 184, 183 ...

International Nuclear Information System (INIS)

In the convolution/superposition algorithm, the energy spectrum should be modified to make the reconstructed dose distribution consistent with the measured dose distribution. The energy spectrum, which gives the best agreement, is not determined uniquely depending on the reconstruction procedure. In this report, the effects of the characteristics of the energy spectrum on the calculation accuracy are evaluated by comparing the percentage depth dose (PDD) and beam profiles for the reference energy spectrum with those calculated for the modified spectrum in order to optimize the energy spectrum modification procedure when 4 and 10 MV X-ray beams are used. Decreasing the number of energy bins brought a larger decrease rate in the computation accuracy than a decrease rate in computation time. Further, the decrease of the number of energy bins led to a change of the ...

International Nuclear Information System (INIS)

The intensity of erbium up-conversion luminescence could be limited by a saturation effect due to increased pump power. We studied the luminescence saturation of the 550 nm emission on erbium-doped, SiO_2-TiO_2 sol-gel powders under pulsed excitation at 979 and 1532 nm. From the latter, the up-converted luminescence intensity decreased with increasing excitation power, whereas no saturation was observed at 979 nm excitation. We proposed that the saturation effect is determined by the pump power, the erbium content and the lifetime of the corresponding first excited states at different pumping schemes.

International Nuclear Information System (INIS)

We have applied photofragment ion imaging to investigate the dissociation dynamics of low-lying, doubly excited states of molecular hydrogen. A doubly excited electronic state is one in which both of the hydrogen electrons reside in excited molecular orbitals. Two-step, two-color multiphoton excitation of H_2, first via 201.8 nm, two-photon excitation into the E, F "1#SIGMA#"+_g(v_E=0, J=1) state, followed by #approx#563 nm, 1+m (m=1, 2) excitation through the B double-prime "1#SIGMA#"+_u(v=0, J=0, 2), D "1#PI#_u(v=2, J=1, 2), and B' "1#SIGMA#"+_u(v=4, J=0, 2) states provides a ready means of populating several low-lying doubly excited states of H_2 at increasing internuclear separations. From these doubly excited repulsive states, both dissociation and autoionization processes are possible. Because the ...

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The expected interstellar antiproton spectrum arising from cosmic-ray interactions in the Galaxy is recalculated, and the modulation of both antiprotons and protons is calculated using a two-dimensional modulation model incorporating gradient and curvature drifts and a wavy current sheet as well as the usual diffusion, convection, and energy-loss effects. Significant differences in the antiproton/proton ratio for different solar magnetic field polarities are predicted as well as a 'low-energy' component for antiprotons below about 1 GeV. 28 refs.

Science.gov (United States)

Cross sections for excitation induced by electron collision between low-lying 1s{sup 2}2s{sup 2}2p{sup 5} and 1s{sup 2}2s2p{sup 6} states of f-like selenium and from these states to singly excited states with the excited electron occupying the M shell have been calculated by relativistic distorted-wave Born procedures. The GRASP{sup 2} code was used for the atomic structure calculations. The continuum orbitals for the construction of continuum states were computed in the distorted-wave approximation, in which the distorted-wave potential used was the spherically averaged potential of the nucleus plus the potential of the bound electrons of the bound state. The cross sections for excitations were computed first by a 233-level multiconfiguration Dirac-Fock (MCDF) configuration expansion and then by a 279-level MCDF configuration expansion. The latter procedure, which also took into account contributions ...

Science.gov (United States)

... In a HEAO 1 study of active galaxies, principally Seyfert 1s, in the 2, 165 keV energy range, Rothschild et al. ... As discussed by Rothschild et al. ...

UK PubMed Central (United Kingdom)

Summary of recent advancesSince their first description more than twenty years ago, Escherichia coli and Klebsiella pneumoniae possessing extended-spectrum...Full Text Available

CERN Document Server

Discussions on a form of a frequency spectrum of wind-driven sea waves just above the spectral maximum continue during the last three decades. In 1958 Phillips made a conjecture that wave breaking is the main mechanism responsible for the spectrum formation. That leads to the spectrum decay $\\sim \\omega^{-5}$, where $\\omega$ is the frequency of the waves. There is a contradiction between the numerous experimental data and this spectrum. The experiments show decay $\\sim\\omega^{-4}$. There are two general ways of the explanation of this phenomenon. The first one (proposed by Banner (1990)) takes into account the Doppler effect due to surface circular currents generated by long waves in the Phillips model. The second approach ascends to the work by Zakharov and Filonenko (1968). It is based on four-wave interactions in the kinetic equation and gives good agreement with the experimental data. In this ...

CERN Document Server

We consider typeIIA supergravity solution of D2-branes and D3-branes localized within D6-branes in the near-core region of D6-branes. With these solutions we can calculate the spectrum of the glueball mass in QCD3 and QCD4. The equation of motion describing the dilaton has the same eigenvalues and the same glueball masses in QCD3 and QCD4. Glueball mass spectrum is the same in the near core region of D6-branes of their M-theory counterpart is KK monopole. We conclude that the glueball mass spectrum is the same in QCD3 and QCD4 by considering the `near-core' limit of D6-branes of which M-theory counterpart (KK monopole background) becomes an ALE space with an $A_{N-1}$ singularity times 7 dimensional Minkowski space $M^{(6,1)}$.

Science.gov (United States)

of injuries, disabilities, and deaths; and 3. Encourage professionals from a wide spectrum of disciplines such as engineering, bioengineering, medicine, health care, public...

UK PubMed Central (United Kingdom)

By the turn of the century, American farmers and ranchers will be producing food and fiber through the application of highly sophisticated systems that involve a broad spectrum of relevant factors--from...Full Text Available

Science.gov (United States)

... 5.9-585/T; thermal stability; solubility in liquid nitrogen, oxygen and Freons; molar extinction coefficients in the visible range and EPR spectrum. ...

International Nuclear Information System (INIS)

The "8"6Kr("3He,n)"8"8Sr and "8"8Sr("3He,n)"9"0Zr reactions were studied to determine whether significant excited 0"+ strength was observed or whether these nuclei exhibited absence of excited state strength generally seen away from shell closures. Various properties of the levels are considered including angular distributions, spins, parities, interference, and enhancement. It is concluded that neither "8"8Sr nor "9"0Zr exhibit the strong proton pairing vibration expected for a closed proton shell nucleus.

Energy Technology Data Exchange (ETDEWEB)

This paper describes a signal simulator which is designed to calibrate eddy current probes. By using simultaneously an excitation coil and an electrically conducting plane, the simulator can emulate signals which correspond to spot welds with different flaws. The presence of a conducting plane allows a wide variation of the amplitude and phase of the excitation coil voltage during the calibration of a probe. A mathematical model for the simulator is derived and used to study the variation of the impedance change upon the parameters of the probe. Numerical computation shows that the impedance change depends in an important way on the frequency of the excitation coil current.

International Nuclear Information System (INIS)

Excitation of the HF electric field in the local plasma resonance region (LPRR) of inhomogeneous plasma by pumping electric field or modulated electron beam results to appearance of the ponderomotive force that presses plasma out of this region. Density cavity is formed in the LPRR due to this field. Further dynamics in this region depends on the plasma properties. For plasma with hot electrons ion-acoustic pulses run away from the cavity. at the local density maximum the new peak of electric field is excited. It results to the formation of new density cavity, etc. For isothermal plasma the density jump is formed.

International Nuclear Information System (INIS)

Using U-120 cyclotron in the course of correlation experiment one studied mechanisms of excitation and decay of "1"2C nucleus states resulting from irradiation of deuterium-polyethylene target by 27.2 MeV energy #alpha#-particle beam via recording of #alpha#-#alpha#-coincidence simultaneously with investigations of #alpha# + d-interactions. Production of "1"2C excited states decaying with the escape of #alpha#-particle and "8Be nucleus in the ground and the excited states is the basic mechanism of the studied #alpha# + "1"2C interaction

International Nuclear Information System (INIS)

The K_#beta#/K_#alpha# X-ray intensity ratios are measured for Mn and Fe and for six other elements with Z lying in the range 49<=Z<=82 following electron capture decay and photon excitation using "2"4"1Am and "5"7Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence of K_#beta#/K_#alpha# values on the mode of excitation in the case of Mn and Fe is attribuited to the chemical effects, while no such dependence is found for the high-Z elements.

International Nuclear Information System (INIS)

In a (p,p') study of "8"8Sr at Esub(p) = 201 MeV both a large resonance centered at 9.4 MeV excitation energy and the known 1"+ state at 3.486 MeV are excited. Several discrete states are observed in the resonance. The cross section of the whole resonance is 27% of a simple particle-hole prediction. The strength of the low-lying 1"+ state is only about 15% of that calculated from a wave function including core-polarization contributions, whereas (e,e') scattering finds about 50%. (orig.).

International Nuclear Information System (INIS)

We review recent progress on experimental studies of collective charge excitations in hole-doped spin ladder system Sr_1_4_-_xCa_xCu_2_4O_4_1, focusing on anomalous features of phase excitation. We also discuss possible candidates for related charge ordered state, together with a controversial issue of the hole density transferred from spin chain layers to spin ladder layers. (author)

Energy Technology Data Exchange (ETDEWEB)

We discuss recent results obtained for the heavy-fermion metals UPd{sub 2}Al{sub 3} and YbRh{sub 2}Si{sub 2}. UPd{sub 2}Al{sub 3} is the first among all superconductors for which tunneling and inelastic neutron-scattering data highlight a non-phononic, i.e., magnetic-exciton mediated, pair state. YbRh{sub 2}Si{sub 2} represents a model system exhibiting pronounced non-Fermi liquid effects above a weak antiferromagnetic phase transition at T{sub N}=70 mK. Upon approaching the quantum critical point (T{sub N}{yields}0), by low doping with Ge, one observes for T<0.3 K disparate behavior in the temperature dependences of both the electrical resistivity and the electronic specific heat as well as a Curie-Weiss law in the uniform magnetic susceptibility, implying uncompensated large 4f moments. These observations indicate a break up of the composite quasiparticles into their local f-spin and itinerant conduction-electron parts.

Science.gov (United States)

Mar 1, 2011 ... Radionuclide X-ray fluorescence analysis. 2: Detection of the X-ray fluorescence radiation excited by radionuclide radiation ...

International Nuclear Information System (INIS)

A scheme of evaluating a generalized three-photon excitation cross section #sigma#/sub (3)/ in neutral atomic argon at 3144.67 A is outlined. Three photons at this wavelength can excite the neutral argon atoms from the ground 3p"6 "1S_0 state to the 3p"54s'[1/2]_1"0 state. The fourth photon will ionize the argon atoms. Assuming linear polarization of the incident laser radiation, contributions from several channels in various energy-level schemes are summed in the evaluation of the transition probability. For a laser linewidth of #DELTA##lambda#/sub L/ = 1 A, our maximum numerical value of the computed result for the three-photon excitation cross section is #sigma#/sub (3)/ = 1.414 x 10/sup -80/ cm"6 s"2. .AE.

Science.gov (United States)

... the effective lifetime of the excited states against spontaneous radiation is only a fe- times the natural lifetime and collisional destruction by ...

Science.gov (United States)

This investigation describes the technique for the detection of the X-ray fluorescent radiation

International Nuclear Information System (INIS)

... UN)) Nel Electronic (Turkey) INIS-TR--0132 1218 p. PHYSICS OF

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

This report discusses: shape coexistence in {sup 184}Pt; nuclear structure of {sup 187}Ir; g-factors of excited states; OLNO-2; and refrigerator development.

International Nuclear Information System (INIS)

... excited states inelastic scattering mev range 10-100 mev range 100-1000

Energy Technology Data Exchange (ETDEWEB)

A flowing carbon dioxide laser was operated at low pressures up to 4 torr. Excitation of the laser was provided using various combinations of direct current (DC), pulsed microwave, and continuous wave (CW) microwave excitation. The microwaves were in the 2.45 GHz band and were coupled into the gas using a slow-wave interdigital transmission line. Laser output of 25 milliwatts (mw) was achieved using a DC discharge only. A combination of a DC discharge and pulsed microwaves doubled the output and resulted in some modulation. Changing the laser gas mixture and pulsed microwave field characteristics allowed some flexibility in the modulation. Lasing was not achieved with excitation from the CW microwaves alone due to the formation of localized discharges. Using pulsed microwaves to sustain the discharge and CW microwaves to pump the laser, a quasi-CW output of 55 mw was achieved.

International Nuclear Information System (INIS)

... functions intermediate structure isobaric analogs level widths mev range

International Nuclear Information System (INIS)

... v. 33(4). beta-minus decay de-excitation delayed gamma radiation iron 64

International Nuclear Information System (INIS)

... Institute of Plasma Physics, National Science Center 'Kharkov Institute of

Science.gov (United States)

Jan 22, 2011 ... dc.description.abstract, The progress in the development of a surface analysis tool based on the excitation of characteristic luminescence ...

International Nuclear Information System (INIS)

... band theory excited states iridium 187 iridium 189 beta decay radioisotopes

Science.gov (United States)

High Cycle Fatigue Initiative Workshop -Active Vibration. Control/Engine. Health Monitoring Session December 10,. 1996. The presentation was titled "Active ...

UK PubMed Central (United Kingdom)

Among 235 extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL) isolates collected from a nationwide surveillance performed in Taiwan, 102 (43.4%) were...Full Text Available

CERN Document Server

The early idea that a non-perturbative gluon condensate affects the spectrum of heavy quarks is revisited in the light of modern simulation techniques. We evaluate the low lying spectrum of bound states of two heavy quarks for large hypothetical quark mass, m_Q > m_b, using non-relativistic QCD and compare with other models to test the consistency.

UK PubMed Central (United Kingdom)

Among 177 extended-spectrum β-lactamase-producing Klebsiella pneumoniae isolates collected from 11 Slovenian hospitals in 2005 and 2006, 60 (34%), from eight hospitals,...Full Text Available

UK PubMed Central (United Kingdom)

Extended-spectrum β-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A technique has been developed at the Idaho National Engineering Laboratory to sum high resolution gamma-ray pulse spectra from systems with multiple Ge detectors. Lockheed Martin Idaho Technologies Company operates a multi-detector spectrometer configuration at the Stored Waste Examination Pilot Plant facility which is used to characterize the radio nuclide contents in waste drums destined for shipment to Waste Isolation Pilot Plant. This summing technique was developed to increase the sensitivity of the system, reduce the count times required to properly quantify the radionuclides and provide a more consistent methodology for combining data collected from multiple detectors. In spectrometer systems with multiple detectors looking at non homogenous waste forms it is often difficult to combine individual spectrum analysis results from each detector to obtain a meaningful result for the total waste container. This is particularly true when the counting statistics in ...

UK PubMed Central (United Kingdom)

CTX-M-type extended-spectrum β-lactamases (ESBLs) have become increasingly common worldwide, with the notable exception of the United States, where TEM- and SHV-type ESBLs have appeared to predominate....Full Text Available

UK PubMed Central (United Kingdom)

CTX-M extended-spectrum beta-lactamases (ESBLs) have emerged as the most common type of ESBL globally, their incidence easily surpassing those of SHV and TEM ESBLs in most locales. This study compared...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

With the help of the symmetry at the P point, we have determined the relations between the force constants and the moduli of elasticity for A-15 compounds. Based on these relations, a semi-experimental method for the study of the lattice dynamic behaviors of A-15 compounds is developed. Numerical calculations of the phonon spectrum of Nb/sub 3/Sn and its temperature dependence have been made, and they are in good agreement with the experimental data.

International Nuclear Information System (INIS)

The cross section database for electron impact excitation and electron impact ionization for hydrogen beam kinetic energies greater than 100 eV was considered, giving for each particular process a reference to a recommended publication of cross sections, as well as the accuracy or estimated accuracy. The work is motivated by the application of neutral beam injection in magnetic confinement devices, such as large tokamaks. 9 refs, 2 figs.

Energy Technology Data Exchange (ETDEWEB)

I discuss several examples of critical phenomena in O(N) models where topological excitations play an important role at criticality. I focus particular attention on the O(2) model in 3D, where recent measurements of the vortex string length distribution in equilibrium suggest the existence of a quantitative picture of the critical behavior in terms of defects. The compatibility of this perspective with renormalization group predictions is examined.

Energy Technology Data Exchange (ETDEWEB)

This work presents a study of the {sup 1}P{sup 0} excited states of He that can be reached by absorption of a single photon carrying an energy close to the double ionization threshold (DIT) (79 eV). Above the DIT, these states are the double continuum states; below, they are the double excited states. These two types of states are tightly coupled to the single continuum states with or without excitation of the residual ion He{sup +}, owing to their degeneracy in energy. In a one-photon process, these states can only be formed owing to the electronic correlations in the system which must be well described to obtain quantitative good results. Our study is a part of the work which aims at a united description of all these doubly excited, ionized-excited, and double continuum states. We use the Hyperspherical R-Matrix with Semiclassical Outgoing Waves (HRM-SOW) method, initially ...

International Nuclear Information System (INIS)

The magnetic excitations of the Kondo compound CePd_2Si_2 below its Neel temperature (T_N = 10 K) have been studied by inelastic neutron scattering. At T = 1.6 K the data are best represented by two dispersive inelastic modes. Their linewidth (#propor to# 0.5 meV) indicates substantial broadening, which is ascribed to Kondo-type local fluctuations. (orig.).

International Nuclear Information System (INIS)

Intrinsic crossluminescence (CRL) of CsBr, CsCl, and of BaF_2 was investigated with electron-beam and synchrotron radiation excitation. From the CRL spectra, the excitation spectra and the reflectivity, energy level schemes were deduced. Extrinsic CRL was observed changing either the initial (CsCl:Br"-) or the final (RbCl:Cs"+; KCl:Cs"+) state of CRL by doping. (author).

Science.gov (United States)

The excitation of compound-nucleus resonances in Y/sup 89/ and Zr/sup 90/ by proton bombardment at 4 to 5.5 Mev of Sr/sup 88/ and Y/sup 89/, respectively, is reported. Shell-model corfigurations were used to interpret the results. (R.E.U.)

International Nuclear Information System (INIS)

An energy sensitive Si(Li) detector XRF analyzer built by ATOMKI, Hungary, has been applied for various analytical purposes in alumina production at the Almasfuezitoe Alumina Company, Hungary. Specifically, the CaO content in red mud was determined by the new XRF technique using isotope excitation sources. The analysis of other components is under way. (R.P.).

International Nuclear Information System (INIS)

In the present work the excitation functions for the reactions "1"4"1Pr(#alpha#,n)"1"4"4Pm and "1"4"1Pr(#alpha#,2n)"1"4"3Pm have been measured experimentally below 50 MeV #alpha#-particle

Energy Technology Data Exchange (ETDEWEB)

The control of nitrogen oxides (NO{sub x}) emissions will become a major challenge in the forthcoming years, in the domain of automotive industry or industrial burners. Pulsed combustion offers an imaginative solution which does not affect the combustion efficiency. In this paper, the efficiency of this method is demonstrated using the burner of a 20 kW domestic boiler. The actuator is simply installed on the air intake. Two types of actuators have been tested successfully: a loudspeaker and a rotative valve. Both can produce 100 to 1000 Hz frequencies and can lead to a reduction of 20% of NO{sub x} emissions. The feasibility of the concept is also demonstrated on a 840 kW liquid fuel-oil burner. The mechanisms involved during an excitation are explained using the CH{sup *} radical imaging. Results show an important reorganization of the flow and of the flame structure. During each excitation cycle, an annular swirl occurs at the leading edge ...

International Nuclear Information System (INIS)

The inelastic energy losses for single collisions of Xe"+ ions with Xe targets have been measured for incident ion energies from 0.3 to 1.2 MeV and for scattering angles from 3"0 to 20"0. The energy losses were found to range from 1 to 11 keV with distinct steps at distances of closest approach of 0.22 and 0.12 A. By comparing these data with earlier ionization data by the same authors these steps are shown to be caused by M-shell excitation. Other excitations observed in the ionization data may be attributed to N-shell excitation. The distances of closest approach at which these excitations occur agree well with calculations by Eichler and Wille and co-workers, giving further evidence of the usefulness of Fano and Lichten's one-electron molecular model and these calculations.

International Nuclear Information System (INIS)

Electron elastic and collisional excitation cross sections from the ground state of potassium are calculated using the noniterative integral-equation method of Henry, Rountree, and Smith [Comput. Phys. Commun. 23, 233 (1981)] in the electron energy range 4#<=#E#<=#200 eV. Configuration-interaction target wave functions that take account of correlation and polarization effects are used to represent the ground state and the six lowest excited states 4p "2P degree, 5s "2S, 3d "2D, 5p "2P degree, 4d "2D, and 6s "2S. Elastic and discrete excitation cross sections are obtained in a seven-state close-coupling (7CC) approximation. The 7CC elastic and excitation cross sections are compared and contrasted. Near threshold the elastic cross section dominates the resonance, 4s "2S#->#4p "2P degree, and the sum of the other remaining excitation cross sections. Comparison of our total ...

International Nuclear Information System (INIS)

Full text: A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through de trending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality. (author)

CERN Document Server

Negative frequency has a physical meaning, the complete description of a frequency signal is a rotating complex signal, in complete description, positive frequency signal exp(iwt) and negative frequency signal exp(-iwt) is two distinguishable and independent frequency signals. Because the real-carrier modulation and demodulation do not distinguish positive and negative frequency, so half of the spectrum resources and signal energy are wasted. The complex-carrier modulation uses the distinguishable positive frequency signal exp(iwt) and negative frequency signal exp(-iwt) as the carrier signals, they can carry different information, so the spectrum resources is full used, the complex-carrier demodulation does not lose signal energy, so the spectrum efficiency is improved.

Energy Technology Data Exchange (ETDEWEB)

The spectrum of antiprotons from dark matter annihilation are calculated using the Lund Monte Carlo program, and simple analytic expressions for the spectrum and low-energy antiproton/proton ratio are derived. Comparing the results with recent upper limits on low energy antiprotons, it is concluded that the reported 4-13 GeV antiproton flux cannot be accounted for by dark matter annihilation. The new upper limits do not provide useful constraints on dark matter particles. They restrict the annihilation rate and imply that annihilation gamma ray and e(+) fluxes would be far below the fluxes produced by cosmic-ray collisions. It may be possible to look for a dark matter halo annihilation signal at antiprotons energies below 0.5 GeV, where the flux from cosmic-ray collisions is expected to be negligible. 32 references.

Energy Technology Data Exchange (ETDEWEB)

Generation of anomalous resistivity and dynamical development of collisionless reconnection in the vicinity of a magnetically neutral sheet are investigated by means of a three-dimensional particle simulation. For no external driving source, two different types of plasma instabilities are excited in the current layer. The lower hybrid drift instability (LHDI) is observed to grow in the periphery of current layer in an early period, while a drift kink instability (DKI) is triggered at the neutral sheet in a late period as a result of the nonlinear deformation of the current sheet by the LHDI. A reconnection electric field grows at the neutral sheet in accordance with the excitation of the DKI. When an external driving field exists, the convective electric field penetrates into the current layer through the particle kinetic effect and collisionless reconnection is triggered by the convective electric field earlier than the DKI is ...

Science.gov (United States)

We study a two-level atom in interaction with a real massless scalar quantum field in a spacetime with a reflecting boundary. The presence of the boundary modifies the quantum fluctuations of the scalar field, which in turn modifies the radiative properties of atoms. We calculate the rate of change of the mean atomic energy of the atom for both inertial motion and uniform acceleration. It is found that the modifications induced by the presence of a boundary make the spontaneous radiation rate of an excited inertial atom oscillate near the boundary and this oscillatory behavior may offer a possible opportunity for experimental tests for geometrical (boundary) effects in flat spacetime. While for accelerated atoms, the transitions from ground states to excited states are found to be possible even in a vacuum due to changes in the vacuum fluctuations induced by both the presence of the boundary and the acceleration of atoms, and this can be ...

International Nuclear Information System (INIS)

Silica glasses containing Pr"3"+ with and without CdS nanoparticles were prepared by sol-gel technique. The influence of CdS nanoparticles on Pr"3"+ doped glass was studied by absorption, photoluminescence and up-conversion. From the measured intensities of various absorption bands of these glasses, the Judd-Ofelt parameters ?_2, ?_4 and ?_6 have been evaluated. The radiative transition probability (A), radiative lifetime (?_R), branching ratio (?_R) and integrated emission cross-section (?_P) were calculated from excited states of "3P_1 and "3P_0 levels. The up-conversion emissions were found in the green, orange and red regions under 800 nm excitation with peaks 559, 612 and 688 nm respectively. On excitation with 370 nm also leads to similar green, orange and red regions.

International Nuclear Information System (INIS)

LaPO4 single crystals lightly doped with Er3+, and codoped with Er3+ and Yb3+ have been grown by spontaneous nucleation in a lead phosphate flux. Absorption and luminescence spectra have been measured in the visible and near-IR regions and the excited state dynamics has been studied upon pulsed laser excitation. The obtained results have allowed the evaluation of the effective emission cross-sections around 1.5 ?m, that have been found to be similar to important oxide laser crystals doped with Er3+. Efficient visible upconversion has been observed upon excitation at 980 nm in the codoped crystals. This behaviour is attributed to Yb3+-Er3+ energy transfer processes.

Energy Technology Data Exchange (ETDEWEB)

The K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios are measured for Mn and Fe and for six other elements with Z lying in the range 49 less than or equal to Z less than or equal to 82 following electron capture decay and photon excitation using /sup 241/Am and /sup 57/Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence of K/sub ..beta..//K/sub ..cap alpha../ values on the mode of excitation in the case of Mn and Fe is attributed to chemical effects, while no such dependence is found for the high-Z elements.

Energy Technology Data Exchange (ETDEWEB)

In this work, we present results of a systematic study of optical properties of Er{sup 3+} ions in 6H SiC. The role of N-donors played in activation of photoluminescence (PL) of erbium at 1.5 {mu}m was investigated. We have confirmed that N-donors are necessary for activation of the Er PL on one hand, whereas on the other we present evidence that N-donors compete for excitation with Er centres. The high-resolution measurements of the Er{sup 3+} PL were performed aiming at determination of crystal field split levels of the {sup 4}I{sub 15/2} ground and {sup 4}I{sub 13/2} first excited multiplet of Er{sup 3+} ions. Careful analysis of temperature evolution of individual PL lines allowed proposing energy level schemes for the ground and first excited states.

Energy Technology Data Exchange (ETDEWEB)

The high selectivity of 201 MeV inelastic proton scattering at forward angles for exciting ..delta..L=0 spin flip transitions is outlined by comparison with (e,e') and 65 MeV (p,p') measurements. A summary of the results obtained on the calcium isotopes, the N=28 isotones, /sup 88/Sr and /sup 90/Zr is presented. The differences in the relative M1 strength distributions between the (p,p') and the (e,e') results are discussed. Preliminary results on /sup 208/Pb are given; the ''isoscalar'' 1/sup +/ state at 5.846 MeV is excited.

Energy Technology Data Exchange (ETDEWEB)

A core-wide in-phase neutron flux oscillation, which took place, for example, at LaSalle-2 in the USA in 1988, is one of the nuclear-coupled thermal hydraulic instabilities in boiling water reactors (BWRs). In this study, an analysis has been performed focusing on the excitation of this type of instability in BWRs due to seismically induced resonance, within the scope of a point kinetics model. For this purpose, the TRAC-BF1 code has been modified to take into account the external acceleration in addition to gravity. As a result of this analysis, it is shown that reactivity insertion can occur accompanied by in-surge of the coolant into the core resulting from excitation. It is also shown that the amount of reactivity inserted largely depends on the degree of stability of the initial state and the amplitude of the seismic wave, whose frequency is the same as the characteristic frequency of the instability. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The excitation function of ({alpha},{ital xn}) reactions on {sup 191}Ir (abundance 37.3%) and on {sup 193}Ir (abundance 62.7%) has been measured for the 17--55 MeV alpha-particle bombarding energy range. The stacked foil activation technique and {gamma}-ray spectroscopy were used to determine the cross sections. The experimental data were compared with calculated values obtained by means of a geometry-dependent hybrid model. The initial exciton number {ital n}{sub 0}=4 with {ital n}=2, {ital p}=2, and {ital h}=0 gives the best agreements with the presently measured results. To calculate the excitation function theoretically a computer code was used. This set of excitation functions provides a data basis for probing the validity of combined equilibrium and preequilibrium reaction models in a considerable energy range.

UK PubMed Central (United Kingdom)

1. Eight deuteranopes matched a mixture of a monochromatic light on the long wave side of the neutral point and a violet (450 nm) primary to a fixed white as well as a monochromatic light on the short...Full Text Available

CERN Document Server

We introduce a methodology for analysis of multiwavelength data from X-ray selected BL Lac (XBL) objects detected in the TeV regime. By assuming that the radio--through--X-ray flux from XBLs is nonthermal synchrotron radiation emitted by isotropically-distributed electrons in the randomly oriented magnetic field of a relativistic blazar jet, we obtain the electron spectrum. This spectrum is then used to deduce the synchrotron self-Compton (SSC) spectrum as a function of the Doppler factor, magnetic field, and variability timescale. The variability timescale is used to infer the comoving blob radius from light travel-time arguments, leaving only two parameters. With this approach, we accurately simulate the synchrotron and SSC spectrum of flaring XBLs in the Thomson through Klein-Nishina regimes. Photoabsorption by interactions with internal jet radiation and the intergalactic background light (IBL) is ...

UK PubMed Central (United Kingdom)

The e.p.r. spectra of the Fe-proteins of nitrogenase from all sources studied have unusual features in that they have very anisotropic linewidths and low integrated intensities. These characteristics...Full Text Available

International Nuclear Information System (INIS)

This paper discusses the clinical application and main objective of testicular imaging. The authors present cases that represent a spectrum of the abnormalities which might be detected by testicular imaging, with special attention given to testicular torsion and the acute diseases which may mimic it clinically. Accuracy of the test is noted.

UK PubMed Central (United Kingdom)

Some cases of autism spectrum disorder (ASD) have mutations in the lipid phosphatase, Pten (phosphatase and tensin homolog on chromosome 10). Tissue...Full Text Available

International Nuclear Information System (INIS)

The observation by inelastic neutron scattering techniques of a high energy peak in the phonon spectrum (14 THz) of V_3Si is reported, and is attributed to a peak in the phonon density of states due to vanadium motions by the incoherent inelastic neutron scattering process.

UK PubMed Central (United Kingdom)

Nemonoxacin (TG-873870) is a novel nonfluorinated quinolone with broad-spectrum activities against Gram-positive and Gram-negative aerobic, anaerobic, and atypical pathogens, as well as against methicillin-resistant...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Using the Klein-Gordon equation with a box potential, a mass formula describing the family of nonflavored meson states with I = 1 is derived. The energy levels calculated agree with those observed within an accuracy of approx. 5%. In the model discussed quarks behave like tachyons.

Science.gov (United States)

The gamma spectrum and gamma - gamma coincidences of /sup 177/W were measured with a Ge(Li) detector. A level scheme was proposed for /sup 177/Ta. (tr-auth)

UK PubMed Central (United Kingdom)

BackgroundThe study aimed at (i) characterizing the mode of transmission of bla_CTX-M and bla_TEM-1 among extended-spectrum-β-lactamase...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundLentiviral vectors (LVs) can efficiently transduce a broad spectrum of cells and tissues, including dividing and non-dividing cells. So far the most widely used method...Full Text Available

UK PubMed Central (United Kingdom)

Extended-spectrum beta-lactamases (ESBL) constitute a key antibiotic-resistance mechanism affecting Gram-negative bacteria, and also an excellent model for studying evolution in real time. A shift in...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

An analysis was made on corrosion suppression mechanism of glycoletherdiaminetetraacetic acid (GEDTA) film made from GEDTA on stainless steel, and its corrosion inhibition effect. Results of analysis using IR spectrum, IR-ATR spectrum, {sup 1} HNMR spectrum, and ESCA spectrum indicated the deposition of the GEDTA film is a chemical deposition. In polarization tests at pH = 5 and 7, both polarization curves shifted to the constant current density side, showing suppression effect in reactions at both pH. When the corrosion environment is made severer, such as to pH = 2 and 4, the corrosion suppression effect of GEDTA became more distinctive. A ferroxyl test identified very little difference between untreated and treated materials. In a chemical pitting test, because oxidant and corrosive anion coexist in the test solution, and GEDTA is stable against corrosive anion Cl {sup {minus}}, the film is unstable ...

UK PubMed Central (United Kingdom)

Japanese medaka (Oryzias latipes) embryos exposed to ethanol have developed craniofacial, cardiovascular and skeletal defects which can be compared with the phenotypic features...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

We calculate mass spectrum of CHS model deformed by an exactly marginal operator, and find that there are tachyons which are not localized in the target space. Similar deformation is discussed in another CFT which corresponds to separated NS5-branes. A condensation of the tachyons is briefly argued.

UK PubMed Central (United Kingdom)

A chromosomally located β-lactamase gene, cloned and expressed in Escherichia coli from a reference strain of the enterobacterial species Kluyvera cryocrescens,...Full Text Available

UK PubMed Central (United Kingdom)

Escherichia coli ILT-1, Klebsiella pneumoniae ILT-2, and K. pneumoniae ILT-3 were isolated in May 1999 in Paris, France, from a rectal swab of a hospitalized...Full Text Available

UK PubMed Central (United Kingdom)

GR99060 and GR99062 are representatives of a series of 1,2,4-triazino[5,6-b]indole compounds. This series possessed broad-spectrum antifungal activity in vitro. The MIC ranges of the two compounds were...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundSLC19A3 (solute carrier family 19, member 3) is a thiamin transporter with 12 transmembrane domains. Homozygous or compound heterozygous mutations in SLC19A3 cause...Full Text Available

UK PubMed Central (United Kingdom)

There are a range of barriers precluding patients from fully engaging in and benefiting from the spectrum of eHealth interventions developed to support patient access to health information, disease...Full Text Available

UK PubMed Central (United Kingdom)

Humanin (HN), a 24-residue peptide, was identified as a novel neuroprotective factor and shows anti-cell death activity against a wide spectrum of Alzheimer's disease (AD)-related cytotoxicities, including...Full Text Available

International Nuclear Information System (INIS)

The High Flux Isotope Reactor (HFIR) located at Oak Ridge National Laboratory is one of the world's most powerful research reactors. In 1996, one year after the demise of the Advanced Neutron Source Project, the U.S. Department of Energy embarked on an aggressive program to upgrade the neutron scattering facilities at the HFIR. These upgrades, which are now in progress, include the installation of larger beam tubes, a high-performance hydrogen cold source, and additional neutron guides and neutron scattering instruments. An extensive analysis effort was performed over the past 4 yr to support the design of the modified beamlines and new user facilities and to assess the impact of the upgrades on the integrity of the existing reactor system. The results of three of these analyses are summarized here. Specifically, results are presented for analyses related to the design of the new cold neutron source (CNS), the assessment of beam tube changes on the anticipated pressure vessel lifetime, ...

International Nuclear Information System (INIS)

Solving a coupled set of differential equations formed by a Fokker-Planck equation and a set of master equations, we can calculate the number of 'prefission' particles (n,p,a), which are emitted from a hot, rotating compound nucleus. Furthermore we get their energy spectrum and their angular momentum distribution. Our results depend sensitively on the friction parameter #gamma#, the inertia M and the fission potential. Comparing the results with experimental data, we may learn something about these quantities. The investigations have been made for "1"8"7Ir and "1"8"5Os. (orig.).

International Nuclear Information System (INIS)

The maximum fissile fuel production capacity of three conceptual fusion breeder systems is examined on the basis of the dominant isotopic-balance processes. Compact relationships involving system power output, plasma and energy multiplication, and parameters which describe the fuel cycle and neutron spectrum in the blanket are established. It is found that the fusion breeder, as characterized herein, possesses a substantial fissile fuel breeding capacity the extent of which is governed primarily by the neutron spectrum in the conversion blanket and the break-even condition of the plasma. (author).

International Nuclear Information System (INIS)

The effect of UV radiation in the wavelength region 230 nm to 302 nm on the ability of an irradiated mammalian cell to reactivate UV-irradiated mammalian virus was tested. An action spectrum for radiation enhanced reactivation (RER) is presented. The shape of the action spectrum points to a combined nucleic acid-protein target for UV radiation effects on this cellular parameter. An analysis of the results of others involving the biochemical and photobiological events involved in RER does not allow us to distinguish which macromolecule is the major contributor to this effect. Studies involving an analogous phenomenon in bacteris (Weigle reactivation) imply that RER and WR amy involve similar mechanisms. (author).

Science.gov (United States)

Seeking effective methods is one of the most important goals in machinery fault diagnosis. The effective methods for gear fault diagnosis have been successively developed in our Institute. This paper is a comprehensive treatise based on our research work of recent years. A mathematical model of vibration signals for defective gears is physically described. Five effective new methods for gear fault diagnosis, such as zoom complex envelope analysis, wideband demodulation technique, bispectrum analysis, correlative spectrum analysis, and maximum entropy spectrum analysis for phase modulated signals, are summarily presented. The listed illustrations prove sufficiently the validation of these methods.

Energy Technology Data Exchange (ETDEWEB)

The existence of a narrow peak in the electronic density of states in A-15 compounds is explained by a strong electron--phonon interaction that leads to the polaron narrowing of the band. An analytic expression relating the transition temperature T/sub c/ to the phonon spectrum is derived under the assumption of a weak and an intermediate-strength coupling. The model allows the explanation of the correlation of T/sub c/ with the number of electrons per atom, the temperature dependence of the resistance, the magnitude and temperature dependence of the magnetic susceptibility, and the electronic specific heat.

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new method for the determination of the energy gap of superconductors. The V/sub max//kT versus ..delta../kT curve was calculated from tunneling theory. The maximum voltage in differential conductance V/sub max/ was measured from the electron tunneling spectrum. From V/sub max//kT and the curve, one can easily calculate the energy gap value ..delta... This method is simple, and the accuracy almost approaches that of the curve-fitting method.

CERN Document Server

The BESS-Polar spectrometer had its first successful balloon flight over Antarctica in December 2004. During the 8.5-day long-duration flight, almost 0.9 billion events were recorded and 1,520 antiprotons were detected in the energy range 0.1-4.2 GeV. In this paper, we report the antiproton spectrum obtained, discuss the origin of cosmic-ray antiprotons, and use antiprotons to probe the effect of charge sign dependent drift in the solar modulation.

CERN Document Server

We provide a both qualitative and quantitative comparison among different approaches aimed to solve the problem of non-linear diffusive acceleration of particles at shocks. In particular, we show that state-of-the-art models (numerical, Monte Carlo and semi-analytical), even if based on different physical assumptions and implementations, for typical environmental parameters lead to very consistent results in terms of shock hydrodynamics, cosmic ray spectrum and also escaping flux spectrum and anisotropy. Strong points and limits of each approach are also discussed, as a function of the problem one wants to study.

Energy Technology Data Exchange (ETDEWEB)

A scheme of evaluating a generalized three-photon excitation cross section sigma/sub (3)/ in neutral atomic argon at 3144.67 A is outlined. Three photons at this wavelength can excite the neutral argon atoms from the ground 3p/sup 6/ /sup 1/S/sub 0/ state to the 3p/sup 5/4s'(1/2)/sub 1//sup 0/ state. The fourth photon will ionize the argon atoms. Assuming linear polarization of the incident laser radiation, contributions from several channels in various energy-level schemes are summed in the evaluation of the transition probability. For a laser linewidth of ..delta..lambda/sub L/ = 1 A, our maximum numerical value of the computed result for the three-photon excitation cross section is sigma/sub (3)/ = 1.414 x 10/sup -80/ cm/sup 6/ s/sup 2/. .AE

UK PubMed Central (United Kingdom)

Amide n –π^* and π-π^* excitations around 200 nm are prominent spectroscopic...Full Text Available