共查询到20条相似文献,搜索用时 31 毫秒
1.
Pang Xiao-feng 《Frontiers of Physics in China》2007,2(4):469-493
A new theory of bio-energy transport along protein molecules, where energy is released by the hydrolysis of adenosine triphosphate
(ATP), has recently been proposed for some physical and biological reasons. In this theory, Davydov’s Hamiltonian and wave
function of the systems are simultaneously improved and extended. A new interaction has been added into the original Hamiltonian.
The original wave function of the excitation state of single particles has been replaced by a new wave function of the two-quanta
quasi-coherent state. In such case, bio-energy is carried and transported by the new soliton along protein molecular chains.
The soliton is formed through the self-trapping of two excitons interacting with amino acid residues. The exciton is generated
by the vibration of amide-I (C=O stretching) arising from the energy of the hydrolysis of ATP. The properties of the soliton
are extensively studied by analytical methods and its lifetime for a wide range of parameter values relevant to protein molecules
is calculated using the nonlinear quantum perturbation theory. The life-time of the new soliton at the biological temperature
of 300 K is large enough and belongs to the order of 10−10 s or τ/τ
0 ⩾ 700. The different properties of the new soliton are further studied. The results show that the new soliton in the new
model is a better carrier of bio-energy transport and it can play an important role in biological processes. This model is
a candidate of the bio-energy transport mechanism in protein molecules.
相似文献
2.
Yu.N. Lobach A.D. Efimov A.A. Pasternak 《The European Physical Journal A - Hadrons and Nuclei》1999,6(2):131-140
Lifetimes of excited states in 110Cd have been measured by the Doppler shift attenuation method in the reaction (α,2nγ) at E
α= 25 MeV. Lifetime values for 8 states and lifetime limits for 3 states were obtained. The band structures of 110Cd have been interpreted in terms of a modified version of the interacting boson model (IBM + 2 q.p.). The calculations explain
well the excitation energies and electromagnetic transition probabilities up to J
π= 16+, except for the 10+
1 state. The structural features are discussed in terms of collective and two quasiparticle excitations.
Received: 20 March 1999 / Revised version: 28 May 1999 相似文献
3.
V.D. Efros H. Oberhummer A. Pushkin I.J. Thompson 《The European Physical Journal A - Hadrons and Nuclei》1998,1(4):447-453
A semi–microscopic model for the low–energy photodisintegration of the 9Be nucleus is constructed, and the experimental data are analyzed with its help. The older radioactive isotope data are supported
by this analysis. The theoretical photodisintegration cross section is derived. The astrophysical rates for the reaction α+α+n→9Be+γ and the reverse photodisintegration of 9Be are calculated. The new reaction rate for α+α+n→9Be+γ is compared with previous estimations.
Received: 19 January 1998 相似文献
4.
Y. Tagaya S. Hashimoto K. Morita Y.H. Pu T. Ariga K. Ohta T. Minemura I. Hisanaga T. Motobayashi T. Nomura 《The European Physical Journal A - Hadrons and Nuclei》1999,5(2):123-125
The α-decay energy and halflife of 195mAt were determined to be 6960±20 keV and 385+69
−51 ms respectively, on the basis of genetic correlations in the 169Tm(36Ar, α6n)195At reaction, while those of 195gAt measured simultaneously were 7105±30 keV and 146+21
−17 ms respectively, reconfirming the previously reported values. A new isotope 199Fr was also produced and identified in the same way in the 169Tm(36Ar, 6n)199Fr reaction, yielding Eα= 7655±40 keV and T1/2= 12+10
−4 ms.
Received: 26 March 1999 相似文献
5.
W. Cassing L. Jarczyk B. Kamys P. Kulessa H. Ohm K. Pysz Z. Rudy O.W.B. Schult H. Ströher 《The European Physical Journal A - Hadrons and Nuclei》2003,16(4):549-561
The lifetime of the Λ-hyperon in heavy hypernuclei measured in proton-Au, -Bi and -U collisions by the COSY-13 Collaboration
at COSY-Jülich has been analyzed to yield τΛ = (145±11) ps. This value for τΛ is compatible with the lifetime extracted from antiproton annihilation on Bi and U targets, albeit much more accurate. Theoretical
models based on the meson exchange picture and assuming the validity of the phenomenological ΔI = 1/2 rule predict the lifetime of heavy hypernuclei to be significantly larger (2-3 standard deviations). Such large differences
indicate that at least one of the assumptions in these models is not fulfilled. A much better reproduction of the lifetimes
of heavy hypernuclei is achieved in the phase space model, if the ΔI = 1/2 rule is discarded in the nonmesonic Λ decay.
Received: 8 August 2002 / Accepted: 20 December 2002 / Published online: 25 March 2003
RID="a"
ID="a"e-mail: h.stroeher@fz-juelich.de
Communicated by Th. Walcher 相似文献
6.
J. Walls J. Clarke S. Cauchi G. Karkas H. Chen W.A. van Wijngaarden 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):9-13
Polarizabilities of several rubidium states were determined by measuring stark shifts of transitions using an electro-optically
modulated laser beam to excite an atomic beam. The voltage required for atoms excited by the laser beam in an electric field
to be simultaneously in resonance as atoms excited by a frequency sideband of the laser in a field free region was measured.
The scalar α
and tensor α
2
polarizabilities were found to be: α
(9
S
1/2
) = 103.77±0.09, α
(10
S
1/2
) = 272.54±0.16, α
(8
D
3/2
) = 230.68±0.25 and α
2
(8
D
3/2
) = 26.55±0.10, α
(8
D
5/2
) = 222.68±0.14 and α
2
(8
D
5/2
) = 51.91±0.10 MHz/(kV/cm)2. The results are 100 times more accurate than previous measurements and are within 1% of those found theoretically using
a Coulomb approximation calculation.
Received 7 September 2000 and Received in final form 6 December 2000 相似文献
7.
A.N. Andreyev D. Ackermann P. Cagarda J. Gerl F. Heßberger S. Hofmann M. Huyse A. Keenan H. Kettunen A. Kleinböhl A. Lavrentiev M. Leino B. Lommel M. Matos G. Münzenberg C. Moore C.D. O'Leary R.D. Page S. Reshitko S. Saro C. Schlegel H. Schaffner M. Taylor P. Van Duppen L. Weissman R. Wyss 《The European Physical Journal A - Hadrons and Nuclei》1999,6(4):381-385
New neutron-deficient isotopes 188,189Po have been produced in the complete fusion reaction of 52Cr ions with a 142Nd target at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the
basis of α-γ and α-conversion electron coincidence measurements and of α-α position and time correlations. In 189Po a ground state to ground state α decay with Eα1= 7540(20) keV, T1/2= 5(1) ms and two fine structure α-decays at Eα2= 7264(15) keV and Eα3= 7316(15) keV have been observed. In 188Po (T1/2= 400+200
−150μs) a ground state to ground state α decay at Eα= 7915(25) keV and a fine structure α decay at Eα= 7350(40) keV have been found. Improved data on the α-decay of 189Bi were obtained.
Received: 15 October 1999 相似文献
8.
J. Kurpeta A. Andreyev J. Äystö A.-H. Evensen M. Huhta M. Huyse A. Jokinen M. Karny E. Kugler J. Lettry A. Nieminen A. Płochocki M. Ramdhane H.L. Ravn K. Rykaczewski J. Szerypo P. Van Duppen G. Walter A. Wöhr 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):49-54
The decay of the neutron–rich isotope 216Bi, produced by proton–induced spallation at the PS Booster–ISOLDE facility, was investigated by β-γγ, αγ coincidence and
spectrum-multiscaling measurements. A new method for reducing isobaric contamination enabled to cover the unknown region “east”
of 208Pb for the isobaric chain A=216. The half-life of the β decay of 216Bi was found as T1/2= 135 ± 5 s. Its decay scheme was extended and the possible shell model configurations are proposed.
Received: 13 July 1999 / Revised version: 22 September 1999 相似文献
9.
Yu.N. Novikov H. Schatz P. Dendooven R. Béraud Ch. Miehé A.V. Popov D.M. Seliverstov G.K. Vorobjev P. Baumann M.J.G. Borge G. Canchel Ph. Desagne A. Emsallem W. Huang J. Huikari A. Jokinen A. Knipper V. Kolhinen A. Nieminen M. Oinonen H. Penttilä K. Peräjärvi I. Piqueras S. Rinta-Antila J. Szerypo Y. Wang J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2001,11(3):257-261
A careful investigation of the isomeric transition of the long-lived state at 228.5 keV excitation energy in 80Y has been done. The HIGISOL facility at the Jyv?skyl? isochronous cyclotron has been used. We used the electron magnetic
transporter to prepare an appropriate source and to measure the electron spectra in clean background conditions. The measured
internal conversion coefficient αK = 0.50±0.07 allows unambiguous 1- identification for the 228.5 keV first excited isomeric state in 80Y. With a “bare" half-life of 6.8±0.5 s found in this work, this state is strongly populated in the rp-process during X-ray
bursts and has therefore to be taken into account in X-ray burst model calculations. However, because of the similarity of
the β-decay half-lives of isomeric and ground states, we find a maximum reduction in the effective β-decay lifetime of 80Y of only 17±2%. Our results pave the way for a future investigation of the impact of the isomeric state on the “effective"
80Y proton capture rate.
Received: 14 March 2001 / Accepted: 10 July 2001 相似文献
10.
S. Kamerdzhiev J. Speth G. Tertychny 《The European Physical Journal A - Hadrons and Nuclei》2000,7(4):483-490
Recent experimental studies of the giant electric resonance region in 58Ni and 40Ca with inelastically scattered α-particles of energy Eα= 240 MeV are analyzed within a microscopic nuclear structure model.
The model includes the continuum RPA and more complex 1p1h⊗phonon configurations. By superimposing the contributions of different
multipoles up to L = 4 we obtain good agreement with the newest (reanalyzed) data for the isoscalar monopole strength and
for the total (α,α′) cross section in 58Ni. Agreement with experiment for the isoscalar monopole resonance in 40Ca is obtained too. We emphasize the necessity of using microscopic transition densities and discuss consequences for the
analyses of such experiments in light and medium mass nuclei. It is shown that the gross structure of the isoscalar monopole
resonance in 40Ca is caused by the 1p1h⊗phonon configurations.
Received: 23 December 1999 / Revised version: 28 February 2000 相似文献
11.
S. Hofmann F.P. Heßberger D. Ackermann S. Antalic P. Cagarda S. Ćwiok B. Kindler J. Kojouharova B. Lommel R. Mann G. Münzenberg A.G. Popeko S. Saro H.J. Schött A.V. Yeremin 《The European Physical Journal A - Hadrons and Nuclei》2001,10(1):5-10
The even-even nucleus 270110 was synthesized using the reaction 64Ni + 207Pb. A total of eight α-decay chains was measured during an irradiation time of seven days. Decay data were obtained for the
ground-state and a high-spin K isomer. The new nuclei 266Hs and 262Sg were identified as daughter products after α-decay. Spontaneous fission of 262Sg terminates the decay chain. The measured data are in agreement with calculations using the macroscopic-microscopic model
and with self-consistent HFB calculations with Skyrme-Sly4 interaction.
Received: 27 November 2000 / Accepted: 16 January 2001 相似文献
12.
F.P. Heßberger S. Hofmann I. Kojouharov D. Ackermann S. Antalic P. Cagarda B. Kindler B. Lommel R. Mann A.G. Popeko S. Saro J. Uusitalo A.V. Yeremin 《The European Physical Journal A - Hadrons and Nuclei》2002,15(3):335-342
The radioactive decay of 217Pa was investigated by means of α-γ-spectroscopy. Fine structure in the ground-state α-decay was established. Ambiguities
in the fine structure of the α-decay of the previously known isomeric state could be clarified by α-γ-coincidence measurements.
A previously unknown α-transition of E
α = (8306 ± 5) keV was detected and identified by means of delayed α-α- and α-γ-γ-coincidence measurements. A second isomeric
state decaying by α-emission was not observed. The quality of the previously reported data of the α-decay fine structure of
217Th was improved.
Received: 29 April 2002 / Accepted: 17 June 2002 / Published online: 19 November 2002
RID="a"
ID="a"e-mail: f.p.hessberger@gsi.de
Communicated by J. ?yst? 相似文献
13.
D. Karevski Y-C. Lin H. Rieger N. Kawashima F. Iglói 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,20(2):267-276
We study the critical behavior of Ising quantum magnets with broadly distributed random couplings (J), such that P(ln J) ∼ | ln J|-1 - α, α > 1, for large | ln J| (Lévy flight statistics). For sufficiently broad distributions, α < , the critical behavior is controlled by a line of fixed points, where the critical exponents vary with the Lévy index, α.
In one dimension, with = 2, we obtained several exact results through a mapping to surviving Riemann walks. In two dimensions the varying critical
exponents have been calculated by a numerical implementation of the Ma-Dasgupta-Hu renormalization group method leading to
≈ 4.5. Thus in the region 2 < α < , where the central limit theorem holds for | ln J| the broadness of the distribution is relevant for the 2d quantum Ising model.
Received 6 December 2000 and Received in final form 22 January 2001 相似文献
14.
B. Fornal R. Broda W. Królas T. Pawłat J. Wrzesiński P.J. Daly P. Bhattacharyya Z.W. Grabowski C.T. Zhang D. Bazzacco S. Lunardi C. Rossi Alvarez G. de Angelis D.R. Napoli 《The European Physical Journal A - Hadrons and Nuclei》1998,1(4):355-357
Prompt and delayed γ-rays in nuclei of the 208Pb region produced in 450 MeV 76Ge +208Pb collisions have been studied at GASP. Yrast states above the α-decaying isomer in 211Po have been located including a 0.25 μs 31/2− isomer at 2135 keV and a 2 μs isomer at 4874 keV.
Received: 22 September 1997 相似文献
15.
K. Van de Vel A.N. Andreyev R.D. Page H. Kettunen P.T. Greenlees P. Jones R. Julin S. Juutinen H. Kankaanpää A. Keenan P. Kuusiniemi M. Leino M. Muikku P. Nieminen P. Rahkila J. Uusitalo K. Eskola A. Hürstel M. Huyse Y. Le Coz M.B. Smith P. Van Duppen R. Wyss 《The European Physical Journal A - Hadrons and Nuclei》2003,17(2):167-171
Gamma rays from excited states of 190Po have been observed using the Jurosphere Ge-detector array coupled to the RITU gas-filled separator. They were associated
with a collective band which from spin 4 onwards resembles the prolate rotational bands known in the isotones 188Pb and 186Hg. This indicates that in 190Po the prolate configuration becomes yrast above I = 2. The experimental results are interpreted in a two-band mixing calculation and are in agreement with α-decay data and
potential energy surface calculations.
Received: 10 January 2003 / Accepted: 19 February 2003 / Published online: 7 May 2003 相似文献
16.
P. Descouvemont 《The European Physical Journal A - Hadrons and Nuclei》2001,12(4):413-419
The 9Be and 9B nuclei are investigated in a microscopic three-cluster model involving α + α +
n (or α + α +
p) configurations. The 8Be (0
+
, 2
+
) +
n and 5He (3/2
-
, 1/2
-
) + α (or mirror) channels are included by taking account of the unstable nature of 8Be and 5He. Spectroscopic properties of 9Be and 9B are analyzed. We show that the 5He + α configurations cannot be neglected to derive accurate results. The 9Be(γ,αα)n photodisintegration cross-section is shown to be mainly determined by 8Be + n channels at low energies, but 5He + α channels become important beyond E
γ≈ 4 MeV.
Received: 7 September 2001 / Accepted: 19 November 2001 相似文献
17.
A.N. Andreyev K. Van de Vel A. Barzakh A. De Smet H. De Witte D.V. Fedorov V.N. Fedoseyev S. Franchoo M. Górska M. Huyse Z. Janas U. Köster W. Kurcewicz J. Kurpeta V.I. Mishin K. Partes A. Plochocki P. Van Duppen L. Weissman 《The European Physical Journal A - Hadrons and Nuclei》2002,14(1):63-75
Alpha-decay properties of the neutron-deficient isotope 185Pb were studied at the PSB-ISOLDE (CERN) on-line mass separator using the resonance ionisation laser ion source (RILIS). The
nuclei of interest were produced in a 1.4 GeV proton-induced spallation reaction of a uranium graphite target. In contrast
to previous studies, two α-decaying isomeric states were identified in 185Pb. The relative production of the isomers, monitored by their α-counting rates, could be significantly changed when a narrow-bandwidth
laser at the RILIS setup was used to scan through the atomic hyperfine structure. Based on the atomic hyperfine structure
measurements, along with the systematics for heavier odd-mass lead isotopes, the spin and the parity of these states were
interpreted as 3/2- and 13/2+ and their nuclear magnetic moments were deduced. The α-decay energy and half-life value for the I
π = 13/2+ isomer are E
α = 6408(5) keV, T
1/2 = 4.3(2) s, respectively; while for the I
π = 3/2- isomer ( T
1/2 = 6.3(4) s) two α-decays with E
α1 = 6288(5) keV, I
α1 = 56(2)% and E
α2 = 6486(5) keV, I
α2 = 44(2)% were observed. By observing prompt α-γ coincidences new information on the low-lying states in the daughter isotope
181Hg was obtained.
Received: 7 February 2002 / Accepted: 19 February 2002 相似文献
18.
J. Mrázek M. Honusek A. Špalek J. Bielčík J. Slívová J. Adam A.A. Pasternak 《The European Physical Journal A - Hadrons and Nuclei》1999,5(4):399-408
The results of in-beam investigations of excited states of 99Ru using the 98Mo(α,3n) reaction are presented. Angular distributions of γ–rays and γ–γ coincidences have been measured. Excited states have
been identified up to an energy of E = 5603 keV and spin of Iπ= 31/2−. Mean lifetimes τ have been determined using the DSA method for eleven levels. Aligned angular momenta are discussed and
the probable (νh
11/2) origin of a backbending at frequency about 0.5 MeV was confirmed. The possible role of (νd
5/2) alignment at frequencies above 0.5 MeV was pointed out.
Received: 13 January 1999 / Revised version: 26 March 1999 相似文献
19.
M.N.A. Abdullah M.S. Mahbub S.K. Das A.S.B. Tariq M.A. Uddin A.K. Basak H.M. Sen Gupta F.B. Malik 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):477-486
Full finite-range macroscopic calculations in the distorted-wave Born approximation have been performed using the molecular
and Michel α-nucleus potentials to analyze the angular distributions of cross-sections of the 27Al(α, d)29Si reaction, at 26.5 and 27.2 MeV incident energies, leading to seven transitions up to the excitation energy E
X = 4.08 MeV of the final nucleus. The parameters of the two types of the α-nucleus potentials are determined from the elastic-scattering
data. Both the molecular and Michel potentials, without any adjustment to the parameters needed to fit the elastic-scattering
data, are able in most cases to reproduce, simultaneously, the absolute cross-sections particularly at large angles, where
the previous calculations failed to reproduce by orders of magnitude, and the gross pattern of angular distributions of the
reaction. The deuteron-cluster spectroscopic factors for most of the seven transitions, deduced using the two α-27Al potentials, differ from those obtained in earlier works. The spectroscopic factor for the ground-state transition, deduced
in the present work for the 25.8 MeV data, agrees well with the shell model prediction.
Received: 15 July 2002 / Accepted: 8 August 2002 / Published online: 10 December 2002
RID="a"
ID="a"e-mail: akbasak2001@Yahoo.com
Communicated by G. Orlandini 相似文献
20.
Z.-C. Yan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(1):15-18
The fully correlated calculations of the Zeeman gJ factors for the first three quartet S states of lithium are presented, including relativistic and radiative corrections of
orders α2, α2
m/M, and α3. The isotope shifts in gJ are predicted precisely for various isotopes of lithium.
Received 4 December 2000 and Received in final form 26 September 2001 相似文献