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1.
The nuclear quadrupole interaction of 204mPb in lead oxides has been measured by γ–γ time differential perturbed angular correlation. Ab-initio calculations of the electric field gradients and X-ray diffraction allowed the assignment of the detected nuclear quadrupole
interactions to the different Pb sites in the PbO phases litharge and massicote as well as in Pb3O4. The TDPAC probe 204mPb was produced with a 204Bi/204mPb-generator at the home laboratory at the University of Leipzig. The use of a high performance liquid chromatography system
increased significantly the yield, the specific activity of 204mPb, and reduced the acidic concentration of the eluate. 相似文献
2.
Murilo F. Cabral Valber A. Pedrosa Sergio A.S. Machado 《Applied Surface Science》2008,254(17):5612-5617
The deposition and characterization of Se films doped with Pb underpotentially deposited (UPD) ad-atoms was studied in this work. The employed experimental techniques were cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, UV-vis spectroscopy and atomic force microscopy. The initial deposition of Se film by chronoamperometry yielded a thin film composed of approximately 700 layers. The Pb UPD on Se was achieved by chronoamperometry in a potential value previously determined in voltammetric experiments. This deposition yielded a deposition charge of approximately 7.5% of the total one. The film resistance altered from 320 Ω cm−2 for Se to 65 Ω cm−2 for the Se/Pb one. Flat band potential values and number of acceptors and donors were also calculated for both films and the values obtained were +0.95 and −0.51 V for Se and Se/Pb, respectively. The Se coating presented 1.2 × 1017 cm−3 acceptors while the Se/Pb one presented 3.2 × 1017 cm−3 donors. The band gap values for both films were 2.4 eV and 1.9 eV, correspondingly. 相似文献
3.
Beker H. Bøggild H. Boissevain J. Cherney M. Dodd J. Esumi S. Fabjan C. W. Fields D. E. Franz A. Hansen K. H. Holzer B. Humanic T. Jacak B. Jayanti R. Kalechofsky H. Kobayashi T. Kvatadze R. Lee Y. Y. Leltchouk M. Lörstad B. Maeda N. Medvedev A. Miake Y. Miyabayashi A. Murray M. Nagamiya S. Nishimura S. Noteboom E. Pandey S. U. Piuz F. Polychronakos V. Potekhin M. Poulard G. Sakaguchi A. Sarabura M. Shigaki K. Simon-Gillo J. Sletten H. Sondheim W. Sugitate T. Sullivan J. P. Sumi Y. van Hecke H. Willis W. J. Wolf K. 《Zeitschrift fur Physik C Particles and Fields》1994,64(2):209-217
K+K+ and K–K– correlations from S+Pb collisions at 200 GeV/c per nucleon and K+K+ correlations from p+Pb collisions at 450 GeV/c per nucleon, are presented as measured by the focusing spectrometer of the NA44 experiment at CERN. Multidimensional fits are performed in order to characterize the kaon-emission volume, which is found to be smaller than the pion-emission volume. 相似文献
4.
The reassignment of spins in the low lying level structure of219Ra obtained from the alpha decay of223Th and minor changes in the spins and the position of the first observed state in the spectroscopy from the nuclear reaction studies208Pb (14C, 3n)219Ra make possible the correlation of these two level structures which were previously unconnected. The resulting level structure shows very tentativeK = 1/2± and 5/2± parity doublet bands and their evolution from anomalous rotational structures into vibrational like bands with alternating spins and opposite parities, reminiscent of weak coupling to an octupole correlated core. The comparison and contrast of the isobars219Ra and219Fr is also presented.One of us (RKS) wishes to thank the National Science Foundation for support under contract PHY92-07336 with Florida State University 相似文献
5.
《The European Physical Journal C - Particles and Fields》2009,61(2):223-235
Measurements of the cross sections for charged current deep inelastic scattering in e
−
p collisions with longitudinally polarised electron beams are presented. The measurements are based on a data sample with an
integrated luminosity of 175 pb−1 collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is given for positively
and negatively polarised electron beams. The differential cross-sections d
σ/dQ
2, d
σ/dx and d
σ/dy are presented for Q
2>200 GeV2. The double-differential cross-section d
2
σ/dxdQ
2 is presented in the kinematic range 280<Q
2<30 000 GeV2 and 0.015<x<0.65. The measured cross sections are compared with the predictions of the Standard Model.
Deceased.
Also affiliated with University College London, United Kingdom.
Now at University of Liverpool, UK.
On leave of absence at CERN, Geneva, Switzerland.
Now at CERN, Geneva, Switzerland.
Now at Bologna University, Bologna, Italy.
Also at Institut of Theoretical and Experimental Physics, Moscow, Russia.
Also at INP, Cracow, Poland.
Also at FPACS, AGH-UST, Cracow, Poland.
Partially supported by Warsaw University, Poland.
Partly supported by Moscow State University, Russia.
Royal Society of Edinburgh, Scottish Executive Support Research Fellow.
Now at University of Salerno, Italy.
Also affiliated with DESY, Germany.
Also at University of Tokyo, Japan.
Now at Kobe University, Japan.
V. Aushev: Supported by DESY, Germany.
Partly supported by Russian Foundation for Basic Research grant no. 05-02-39028-NSFC-a.
STFC Advanced Fellow.
Nee Korcsak-Gorzo.
This material was based on work supported by the National Science Foundation, while working at the Foundation.
Now at University of Kansas, Lawrence, USA.
Also at Max Planck Institute, Munich, Germany, Alexander von Humboldt Research Award.
Also working at Max Planck Institute, Munich, Germany.
Now at KEK, Tsukuba, Japan.
Now at Nagoya University, Japan.
Member of Department of Radiological Science, Tokyo Metropolitan University, Japan.
Now at SunMelx Co. Ltd., Tokyo, Japan.
Also at Hamburg University, Inst. of Exp. Physics, Alexander von Humboldt Research Award and partially supported by DESY,
Hamburg, Germany.
Also at Łódź University, Poland.
Member of Łódź University, Poland.
Also at University of Podlasie, Siedlce, Poland.
Now at Lund Universtiy, Lund, Sweden.
Now at Institute of Aviation, Warsaw, Poland.
Supported by the research grant no. 1 P03B 04529 (2005–2008).
This work was supported in part by the Marie Curie Actions Transfer of Knowledge project COCOS (contract MTKD-CT-2004-517186).
Now at University of Bonn, Germany.
Now at DESY group FEB, Hamburg, Germany.
Also at Moscow State University, Russia.
Supported by the Natural Sciences and Engineering Research Council of Canada (NSERC). 相似文献
6.
Elastic scattering of 7, 9, 11, 20 and 26 MeV neutrons from 208Pb has been measured with the Ohio University Tandem Van de Graaff accelerator. Standard pulsed beam time-of-flight techniques were employed. Measurements of the incident flux at 0° were used to normalize the differential cross sections. The measured cross sections were corrected for dead time, detector efficiency, flux attenuation, multiple scattering, finite geometry, neutron source anisotropy and compound elastic contribution. Relative uncertainties are estimated to be between 5%–10% and the uncertainty in the normalization is estimated to be less than 5 %. The data were used to obtain neutron optical potential parameters. A comparison with proton optical parameters is presented, and the (p, n) quasi-elastic cross section is calculated and compared with available data. Deformation parameters for the 3? state (Q = ?2.615 MeV) and 5ā (Q = ?3.198 MeV) in 208Pb were obtained at incident energies of 11 and 26 MeV. 相似文献
7.
E. Gerlic J. Ka¨llne H. Langevin-Joliot J. Van de Wiele G. Duhamel 《Physics letters. [Part B]》1975,57(4):338-340
Energy spectra have been measured for the (τ, α) reaction at 205 MeV on90Zr, 118,124Sn and 208Pb. Results on the valence neutron shells and on the inner 1f7/2 shell in 90Zr, 1g9/2 subshell in 118,124Sn (T< and T> components) and 1h11/2 subshell in 208Pb are presented. 相似文献
8.
It is shown that characteristic optical absorption bands of Pb ions in mixed aqueous solutions of NaCl and PbCl2 can be used for a quantitative determination of lead in NaCl crystals. The optimum conditions for such an analytical procedure are presented. On the basis of this it is possible to determine correctly even 4 ppm Pb in NaCl specimens of only 0·05 cm3. As an example of the applicability of this method the Pb distribution was investigated in crystals grown by different methods from melts of different Pb concentrations.Dedicated to Dr. A.Bohun, DrSc., on his 65th birthday.The authors thank Mrs. E.Horn for performing all the measurements with the highest degree of accuracy. 相似文献
9.
M. D. Lunney G. Audi C. Borcea M. Dedieu H. Doubre M. Duma M. Jacotin J. -F. Képinski G. Le Scornet M. de Saint Simon C. Thibault 《Hyperfine Interactions》1996,99(1):105-114
The MISTRAL project (Mass measurements at ISolde using a Transmission RAdiofrequency spectrometer on-Line) is scheduled to begin experiments towards the end of 1996. With high resolution (105), potentially high accuracy (5×10–7) and excellent sensitivity (10 s–1), the MISTRAL spectrometer promises to provide needed mass measurements in regions of very-short lived nuclei. The spectrometer operation principles are described and a discussion concerning the interest in using highly charged ions is presented.CSNSM, Orsay; IAP, Bucharest; PPE Division, CERN; GSI, Darmstadt; University of Mainz; McGill University, Montreal; IPN, Orsay; Chalmers University, Göteborg; University of Giessen and the ISOLDE Collaboration. 相似文献
10.
H.C. Manjunatha 《Isotopes in environmental and health studies》2014,50(4):555-564
In the natural uranium-238 decay series, pure beta isotopes such as 234Th, 234Pa, 214Pb, 214Bi, 210Pb and 210Bi are released. The few lead isotopes such as 211Pb, 212Pb, 213Pb and 215Pb are good beta emitters. In certain nuclear reactions of reactor these isotopes are released. These beta isotopes have maximum beta energies, which induce the bremsstrahlung radiation. The bremsstrahlung component of these beta isotopes has been traditionally ignored in dosimetry calculations. The shapes of bremsstrahlung spectra are a basic ingredient in the understanding and quantification of beta-ray dosimetry. The bremsstrahlung spectra produced by these high-energy isotopes such as 234Th, 234Pa, 214Pb, 214Bi, 210Pb, 210Bi, 211Pb, 212Pb, 213Pb and 215Pb in bone, muscle and teeth are studied, and the computed spectral distributions are presented. The spectral shapes are primarily responsible for variations in the shapes of depth–dose distributions. They are intended to provide a quick and convenient reference for spectral shapes and to give an indication of the wide variation in these shapes. The evaluated beta bremsstrahlung dose as a function distance for the studied nuclides is also presented. The efficiency, intensity and dose rate of bremsstrahlung induced by beta isotopes of natural uranium-238 decay series and beta-emitting lead isotopes in human tissues such as brain, breast, heart, kidney, liver, muscle, pancreas and bone have also been studied in the present investigation. The values of bremsstrahlung dosimetric parameters are low for pancreas, but they are high for bone. For all studied tissues these parameters are high for 234Pa, but low for 210Pb. 相似文献
11.
M. Rejmund K.H. Maier R. Broda B. Fornal M. Lach J. Wrzesiński J. Blomqvist A. Gadea J. Gerl M. Górska H. Grawe M. Kaspar H. Schaffner C. Schlegel R. Schubart H.J. Wollersheim 《The European Physical Journal A - Hadrons and Nuclei》1998,1(3):261-266
High spin states in nuclei around 208Pb were populated in deep inelastic collisions of 76Ge, 136Xe, and 208Pb projectiles with 208Pb targets at beam energies about 12% above the Coulomb barrier. New states in 209Pb were found by measuring γ-γ-coincidences. They are interpreted as the yrast states that originate from the coupling of
one neutron to the lowest excitations of the 208Pb core. The results are discussed in the frame of the shell model.
Received: 22 November 1997 相似文献
12.
13.
The impingement and interdiffusion of adsorbed Pb and Bi layers spreading from separated 3D pure bulk sources on Cu(1 0 0) has been studied, at T = 513 K, by in situ scanning Auger microscopy. When the leading edges of the pure Pb and Bi diffusion profiles impinge, they both consist of low-coverage lattice gas surface alloyed phases. In these low-coverage phases, Pb displaces surface alloyed Bi and the point of intersection of the profiles drifts towards the Bi source. These features lead to the conclusion that Pb atoms are more strongly bound at surface alloyed sites in Cu(1 0 0) than Bi atoms. Once the total coverage (Pb + Bi) on the substrate reaches about one monolayer, Pb and Bi are dealloyed from the substrate, and the interdiffusion profiles become essentially symmetric. Pb and Bi mix in all proportions, with an interdiffusion coefficient of ∼10−13 m2/s. This is considerably smaller than the self-diffusion coefficients previously observed for pure Pb and Bi in their respective high-coverage phases, indicating that the mechanism of interdiffusion is different from that of self-diffusion. As interdiffusion proceeds, the point of intersection of the Pb and Bi profiles reverses its drift direction, leading to the conclusion that binding of Bi atoms to the Cu(1 0 0) substrate is stronger than that of Pb atoms in the highest-coverage surface dealloyed layers. 相似文献
14.
The weak coupling particle-vibration model is extended to lowlying neutron resonances in certain even-even or odd-odd nuclei by coupling the extra particle to core excited states of the odd mass target. The odd hole or particle in the target is treated as a passive spectator. 208Pb and 210Bi are studied as test cases and the calculated resonance quantities are in good general agreement with the average features of high resolution experiments. The resonances in 208Pb and 210Bi are related to the same intrinsic doorway in 209Pb. The 210Bi data is presented here for the first time. 相似文献
15.
C.N. Papanicolas J. Heisenberg J. Lichtenstadt J.S. McCarthy 《Physics letters. [Part B]》1981,99(2):96-100
We report the identification of new high multipolarity transitions in 207Pb and 206Pb by the measurement of their form factor. A comparison to the corresponding excitations in 208Pb is presented. 相似文献
16.
17.
G. Benzoni F. Azaiez S. Leoni S. Battacharyya R. Borcea A. Bracco L. Corradi D. Curien G. De France Zs. Dombrádi E. Fioretto S. Franchoo S. Grevy F. Ibrahim S. Iulian G. Mukherjee A. Navin G. Pollarolo N. Redon P. H. Regan M. Rejmund C. Schmitt G. Sletten D. Sohler M. Stanoiu S. Szilner D. Verney 《The European physical journal. Special topics》2007,150(1):83-86
A study of deep-inelastic and multi-nucleon transfer reactions to populate neutron-rich
O, Ne and F nuclei is here presented. The reaction under analysis employed a beam of radioactive
24Ne at 7.9 AMeV, provided by the
SPIRAL facility at Ganil, impingin on a 208Pb target. The reaction products have been
detected in the VAMOS spectrometer in coincidence with gamma rays
measured by the EXOGAM array. Preliminary results here presented show a selectivity
in the population of states of different nature. 相似文献
18.
Summary An accurate dating of recent Ionian Sea sediment cores has been performed by the210Pb radiometric method and by a detailed tephroanalysis. The markers of the historical volcanic eruptions which occurred in
the Campanian area (Vesuvius, Phlegrean Fields, Ischia) during the last two millenia have been identified along the cores.
Among the others, the famous Plinian Vesuvius eruption of 79 AD, which buried the Roman town of Pompei, has been recognized.
Direct210Pb dating is limited to the last two centuries. The tephroanalysis demonstrates that the sedimentation rate estimated by the210Pb method is correct and it is constant, at least for the last 2 ky. The presence of the137Cs peak due to the intense activity of nuclear-weapon testing in the atmosphere in 1963–64 AD assures that the top of the
core is present and not disturbed. The high precision of the core dating allows to transform the depth scale into a time scale
with an accuracy of ∼1%. The analysis of several cores taken in the same area demonstrates that the results presented here
are of general validity, at least in this region. The carbonatic mud deposited in the last millennia in the Gallipoli Terrace
can be successfully utilized for investigating the environmental conditions in the recent past. 相似文献
19.
A. S. Provorov E. I. Prakhin A. G. Sizykh M. Yu. Reushev S. V. Borozdun L. S. Évert 《Journal of Applied Spectroscopy》2004,71(5):760-762
The results of investigations of the microelemental composition of urine by the method of emission spectrum analysis are presented. The samples of urine under study were introduced into the arc discharge region by a fulgurator without preliminary preparation of the samples. The content of Pb in the urine samples at a concentration of about 10–9 g/ml has been determined. 相似文献
20.
Formulae are presented concerning the effects of virtual Coulomb excitation on the transfer of nucleons between heavy ions at energies below the Coulomb barrier. These formulae are applied towards calculation for the 208Pb(16O, 17O)207Pb reaction at 69.1 MeV. Generally, the effect is found to be of the order of 10% but it is not discernable owing to the small reaction cross sections. Suggestions are presented for extending the analysis to higher energies where the situation is more favourable. 相似文献