共查询到20条相似文献,搜索用时 24 毫秒
1.
L.V. Grigorenko R.C. Johnson I.G. Mukha I.J. Thompson M.V. Zhukov 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):125-129
The theoretical approach to the two-proton radioactivity and three-body decays developed in (L.V. Grigorenko, R.C. Johnson,
I.G. Mukha, I.J. Thompson, M.V. Zhukov, Phys. Rev. Lett. 85, 22 (2000) and to be published in Phys. Rev. C) is applied to the range of light nuclear systems. We study nuclear structures,
widths, and momentum correlations for the decay fragments. Strong contradictions with experiment, as well as effects of special
interest, are found in 12O and 16Ne nuclei.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: l.grigorenko@surrey.ac.uk 相似文献
2.
M. Jazbinšek M. Zgonik S. Takekawa M. Nakamura K. Kitamura H. Hatano 《Applied physics. B, Lasers and optics》2002,75(8):891-894
The wavelength dependence of the space-charge field as induced in near-stoichiometric LiTaO3 crystals is investigated by measuring the bulk photogalvanic effect and the photoconductivity. LiTaO3 crystals of composition nearer to stoichiometry exhibit a pronounced reduction of the saturated space-charge field, which
results from a larger increase in the photoconductivity relative to the photogalvanic effect. Especially, at near-UV wavelengths,
the saturated space-charge field of the order of 0.1 kV/cm reaches a minimum that is two orders of magnitude lower than typical
values observed in undoped near-stoichiometric LiNbO3.
Received: 11 July 2002 / Revised version: 2 September 2002 / Published online: 20 December 2002
RID="*"
ID="*"Corresponding author. Fax: +41-1/633-1056, E-mail: mojca@fiz.uni-lj.si 相似文献
3.
G. Schönwaßer H. Hübel G.B. Hagemann H. Amro R.M. Clark M. Cromaz R.M. Diamond P. Fallon B. Herskind G. Lane W.C. Ma A.O. Macchiavelli S.W. Ødegård G. Sletten D. Ward J.N. Wilson 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):435-437
Average transition quadrupole moments in the yrast triaxial superdeformed bands of 163Lu, 164Lu and 165Lu were determined in a Doppler-shift attenuation-method experiment. Fractional Doppler shifts were determined in γ-ray coincidence
spectra measured with the Gammasphere array. The transition quadrupole moments derived from these data show a decrease from
163Lu to 165Lu which is not predicted by total-energy surface calculations.
Received: 12 August 2002 / Accepted: 23 October 2002 / Published online: 10 December 2002
RID="a"
ID="a"e-mail: schoenwa@iskp.uni-bonn.de
Communicated by D. Schwalm 相似文献
4.
We present a method for determining the effective driving potential for a molecular motor from measurements of its stochastic
position versus time. In developing the method we can make precise the previously vague notions of ‘Brownian ratchet’ and
‘power stroke’, and suggest means to experimentally distinguish between the two. In particular, we distinguish between two
kinds of ratchets: ratchets that rectify large fluctuations and ratchets that bias small fluctuations.
Received: 24 October 2001 / Accepted: 11 February 2002 / Published online: 22 April 2002 相似文献
5.
100-W average-power, high-energy nanosecond fiber amplifier 总被引:5,自引:0,他引:5
J. Limpert S. Höfer A. Liem H. Zellmer A. Tünnermann S. Knoke H. Voelckel 《Applied physics. B, Lasers and optics》2002,75(4-5):477-479
We report on the fiber-based amplification of a Q-switched Nd:YAG thin-disk laser. At repetition rates between 3 and 50 kHz
output powers up to 100 W are generated. Pulse energies up to 4 mJ, with diffraction-limited beam quality, are generated in
a 30-μm Yb-doped large-mode-area fiber, furthermore pulse energies up to 8 mJ are achieved from a multimode fiber amplifier.
Received: 8 May 2002 / Revised version: 10 July 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +49-3641/65-7680, E-mail: Jens.Limpert@uni-jena.de 相似文献
6.
A. Hürstel M. Rejmund E. Bouchez P.T. Greenlees K. Hauschild S. Juutinen H. Kettunen W. Korten Y. Le Coz P. Nieminen Ch. Theisen A.N. Andreyev F. Becker T. Enqvist P.M. Jones R. Julin H. Kankaanpää A. Keenan P. Kuusiniemi M. Leino A.-P. Leppänen M. Muikku J. Pakarinen P. Rahkila J. Uusitalo 《The European Physical Journal A - Hadrons and Nuclei》2002,15(3):329-334
Prompt and delayed gamma-ray spectroscopy of very neutron-deficient bismuth isotopes 187, 189Bi has been performed using the Recoil Decay Tagging (RTD) method. The isomeric i
13/2 states have been identified and their lifetimes have been measured. The systematics of these long-lived M2 isomers has been extended to the proton-unbound isotopes. The general behaviour of single-proton states is discussed within
the systematics and interpreted within the shell-model framework.
Received: 2 May 2002 / Accepted: 3 June 2002 / Published online: 19 November 2002
RID="a"
ID="a"e-mail: wkorten@cea.fr
RID="b"
ID="b"Present address: GANIL, Caen, France.
RID="c"
ID="c"Present address: Radiation and Nuclear Safety Authority, P.O. Box 14, FIN-00881 Helsinki.
Communicated by D. Schwalm 相似文献
7.
8.
J.K. Jian X.L. Chen W.J. Wang L. Dai Y.P. Xu 《Applied Physics A: Materials Science & Processing》2003,76(2):291-294
Single-crystalline SnO2 nanowires, nanobelts and nanodendrites were synthesized by a simple gas-reaction route on a large scale at 900 °C. They were
characterized by means of X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive
X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). FE-SEM images
showed that the products consisted of nanowires, nanobelts and nanodendrites that represent a novel morphology reported for
the first time. XRD, SAED and EDS indicated that they were single-crystalline tetragonal SnO2. The influence of experimental conditions on the morphologies of the products is discussed.
Received: 3 June 2002 / Accepted: 10 June 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: 86-10/82649531, E-mail: xlchen@aphy.iphy.ac.cn 相似文献
9.
M. Girod J. Libert J.-P. Delaroche P. Romain 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):209-212
The structure properties of the even-even nuclei 226, 228, 230, 232, 234Th, 230, 232, 234, 236, 238, 240U, 240, 242, 244, 246Pu, and 242, 244, 246, 248Cm have been investigated at normal and superdeformed shapes in microscopic mean-field calculations based on Gogny force.
Collective levels are predicted from constrained Hartree-Fock-Bogoliubov and configuration mixing calculations. Two quasiparticle
states are also predicted from blocking calculations for neutron and proton configurations. Predictions are shown and compared
with experimental data at superdeformed shapes.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: michel-g.girod@cla.tr 相似文献
10.
N.A. Orr 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):109-113
Clustering is a relatively widespread phenomenom which takes on many guises across the nuclear landscape. Selected topics
concerning the study of halo systems and clustering in light, neutron-rich nuclei are discussed here through illustrative
examples taken from the Be isotopic chain. The production and detection of multineutron clusters is also briefly presented.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: orr@caelav.in2p3.fr 相似文献
11.
R.-D. Herzberg N. Amzal J.E. Bastin F. Becker P.M.T. Brew P.A. Butler A.J.C. Chewter J.F.C. Cocks O. Dorvaux K. Eskola J. Gerl P.T. Greenlees N.J. Hammond K. Hauschild K. Helariutta F. Heßberger M. Houry A. Hürstel R.D. Humphreys G.D. Jones P.M. Jones R. Julin S. Juutinen H. Kankaanpää H. Kettunen T.L. Khoo W. Korten P. Kuusiniemi Y. Le Coz M. Leino A.P. Leppänen C.J. Lister R. Lucas M. Muikku P. Nieminen R.D. Page T. Page P. Rahkila P. Reiter Ch. Schlegel C. Scholey G. Sletten O. Stezowski Ch. Theisen W.H. Trzaska J. Uusitalo H.J. Wollersheim 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):205-208
In-beam conversion electron spectroscopy experiments have been performed on the transfermium nuclei 253, 254No using the conversion electron spectrometer SACRED in nearly collinear geometry in conjunction with the gas-filled separator
RITU at the University of Jyv?skyl?. The experimental setup is discussed and the spectra are compared to Monte Carlo simulations.
The implications for the ground-state configuration of 253No are discussed.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: rdh@ns.ph.liv.ac.uk
RID="b"
ID="b"Present address: GANIL, F-14021 Caen, France.
RID="c"
ID="c"Permanent address: IReS Strasbourg, IN2P3-CNRS, F-67037-Strasbourg, France.
RID="d"
ID="d"Present address: CEA/DIF DCRE/SDE/LDN F-91680 Bruyeres-le-Chatel.
RID="e"
ID="e"Present address: Daresbury Laboratory, Daresbury WA4 4AD, UK.
RID="f"
ID="f"Permanent address: IPN Lyon, IN2P3-CNRS, F-69037 Lyon, France. 相似文献
12.
J.K. Jian X.L. Chen T. Xu Y.P. Xu L. Dai M. He 《Applied Physics A: Materials Science & Processing》2002,75(6):695-697
SnO2 nanowires were synthesized using a direct gas reaction route and were characterized by X-ray powder diffraction (XRD), scanning
electron microscopy (SEM), selected-area electron diffraction (SAED), high-resolution transmission electron microscopy (HRTEM)
and Raman-scattering spectroscopy. XRD, SEM, SAED and HRTEM indicated that the products were tetragonal SnO2 nanowires with diameters of 10–50 nm. The nanowires were single crystal and solid inside. Dendritic nanowires were observed
for the first time. Three vibrational modes were observed in the Raman spectra of the samples.
Received: 7 January 2002 / Accepted: 11 April 2002 / Published online: 19 July 2002 相似文献
13.
H.R. Zeng G.R. Li Q.R. Yin Z.K. Xu 《Applied Physics A: Materials Science & Processing》2003,76(3):401-404
Pb(Zr,Ti)O3 (PZT) ferroelectric thin film was prepared by the sol-gel technique and crystallized with a (111) preferred orientation.
The domain structure and polarization reversal behavior were investigated by using scanning force microscopy (SFM) piezoresponse
mode at the nanometer scale. A step structure of approximately 30 nm in width was directly observed, which was formed during
the polarization reversal process. The presence of the step structure reveals that the forward domain-growth mechanism is
the dominant domain-switching process in our PZT thin films.
Received: 6 August 2002 / Accepted: 9 August 2002 / Published online: 28 October 2002
RID="*"
ID="*"Corresponding author. Fax: +86-21/5241-3122, E-mail: huarongzeng@163.net 相似文献
14.
W.J. Zhang C.Y. Chan K.M. Chan I. Bello Y. Lifshitz S.T. Lee 《Applied Physics A: Materials Science & Processing》2003,76(6):953-955
Large-area, 1-μm-thick cubic boron nitride (cBN) films were deposited on (001) silicon substrates by electron-cyclotron-resonance-enhanced
microwave-plasma chemical vapor deposition (ECR-MP CVD) in a mixture of He-Ar-N2-BF3-H2 gases. With the assistance of fluorine chemistry in the gas phase and substrate reactions, the phase purity of the sp3-configuration was improved to over 85% at a reduced substrate bias voltage of -40 V. The grown films show clear Raman transversal
optical (TO) and longitudinal optical (LO) phonon vibration modes, characteristic of cBN. Such Raman spectral characteristics
are the first ever observed in cBN films prepared under ECR-MP CVD conditions.
Received: 3 May 2002 / Accepted: 7 May 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +852-2788/7830, E-mail: apwjzh@cityu.edu.hk 相似文献
15.
Desrosiers Patrick Lapointe Luc Mathieu Pierre 《Communications in Mathematical Physics》2003,233(3):383-402
We call superpartitions the indices of the eigenfunctions of the supersymmetric extension of the trigonometric Calogero-Moser-Sutherland
model. We obtain an ordering on superpartitions from the explicit action of the model's Hamiltonian on monomial superfunctions.
This allows to define Jack superpolynomials as the unique eigenfunctions of the model that decompose triangularly, with respect
to this ordering, on the basis of monomial superfunctions. This further leads to a simple and explicit determinantal expression
for the Jack superpolynomials.
Received: 11 May 2001 / Accepted: 16 August 2002 Published online: 7 November 2002
Communicated by R. H. Dijkgraaf 相似文献
16.
S. Pereira J.E. Sipe M.A. Bader S. Soria G. Marowsky 《Applied physics. B, Lasers and optics》2002,75(6-7):635-640
We theoretically demonstrate the feasibility of using a grating-waveguide structure (GWS) as a loss-tolerant, narrow-band
reflector in the UV. We simulate device operation using a Green-function technique. Our numerical simulations indicate that
a GWS with a 25-nm grating can be used as a 95% reflector for 157-nm light, even in the presence of intensity absorptions
of 50 cm-1.
Received: 23 July 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +49-551/5035-99, E-mail: mbader@llg.gwdg.de 相似文献
17.
G. Montagnoli S. Beghini F. Scarlassara A.M. Stefanini L. Corradi C.J. Lin G. Pollarolo Aage Winther 《The European Physical Journal A - Hadrons and Nuclei》2002,15(3):351-356
The two systems 40Ca + 90,96Zr have been studied by measuring nucleon transfer reactions at two energies near the Coulomb barrier, thus complementing
the available sub-barrier fusion cross-sections. Angular distributions for various transfer channels have been determined.
Significantly larger neutron transfer cross-sections are found for the target 96Zr that exhibits the larger enhancement in the sub-barrier fusion cross-sections. All data have been analyzed with a new model
for heavy-ion collisions that calculates simultaneously transfer cross-sections, fusion excitation functions and barrier distributions.
The model gives a good account of both transfer and fusion data.
Received: 2 May 2002 / Accepted: 4 June 2002 / Published online: 26 November 2002
RID="a"
ID="a"e-mail: montagnoli@pd.infn.it, Fax +39049 8277102, Tel. +39049 8277117.
RID="b"
ID="b"On leave from the China Institute for Atomic Energy, 102413 Beijing, China.
Communicated by C. Signorini 相似文献
18.
K.-I. Tezuka 《The European Physical Journal C - Particles and Fields》2002,25(3):465-468
We construct Poisson brackets at the boundaries of open strings and membranes with constant background fields which are compatible
with their boundary conditions. The boundary conditions are treated as primary constraints which give infinitely many secondary
constraints. We show explicitly that we need only two (the primary one and one of the secondary ones) constraints to determine
the Poisson brackets of strings. We apply this to membranes by using canonical transformations.
Received: 2 May 2002 / Revised version: 29 May 2002 / Published online: 16 August 2002
RID="a"
ID="a" e-mail: tezuka@physics.s.chiba-u.ac.jp 相似文献
19.
R. Denk K. Piglmayer D. Bäuerle 《Applied Physics A: Materials Science & Processing》2002,74(6):825-826
A regular lattice of SiO2 microspheres on a quartz support is used as a microlens array for laser-induced nanopatterning of polyethylene terephthalate
foils.
Received: 2 January 2002 / Accepted: 6 January 2002 / Published online: 27 March 2002 相似文献
20.
C. Affolderbach M. Stähler S. Knappe R. Wynands 《Applied physics. B, Lasers and optics》2002,75(6-7):605-612
Optical magnetometers have reached sensitivities that make them interesting candidates for the measurement of weak magnetic
fields also outside physics laboratories. In order to overcome problems with stray magnetic fields a common solution with
existing magnetometers is to operate a pair of them in a gradiometer configuration: one sensor measures the signal plus the
stray fields, while the other one is mounted such that it is only influenced by the stray fields. In the difference signal
the stray fields cancel. We have constructed such a gradiometer consisting of two sensors based on coherent population trapping
(CPT) resonances in a thermal cesium vapor. Using a magnetic bias field the intrinsically scalar CPT magnetometer can be turned
into a true vector magnetometer that is insensitive to magnetic fields perpendicular to a chosen measurement direction. We
describe how to align and calibrate the gradiometer. Stray field suppression by more than two orders of magnitude has been
achieved, limited by the sensitivity of the magnetometer. This makes possible the detection of picotesla flux density changes
in a weakly shielded or even unshielded environment.
Received: 3 April 2002 / Published online: 15 November 2002
RID="*"
ID="*"New address: Département de Physique, Université de Fribourg, Chemin du Musée 3, 1700 Fribourg, Switzerland
RID="**"
ID="**"Corresponding author. Fax: +41-26/300-9631, E-mail: robert.wynands@unifr.ch 相似文献