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41.
F.?P.?He?bergerEmail author S.?Hofmann I.?Kojouharov D.?Ackermann 《The European Physical Journal A - Hadrons and Nuclei》2004,22(2):253-260
Isomeric states in 210-215Ra have been populated by the decay of the compound nuclei 216,220Ra produced in irradiations of 204,208Pb with 12C at
MeV. Published values for
-ray energies and half-lives were confirmed for
Ra. Our data for
Ra agree with the
-energies and the half-life measured at the RITU separator, University of Jyväskylä (Finland). Its decay pattern is complex. Two series of
-rays of
keV and
keV were observed. A half-life of
s was measured. The isomeric state is attributed to an 8 + state at E
* = 2053.8keV. A previously unknown isomeric state was assigned to
Ra. It has a half-life of (
)
and it decays by emission of
-rays with energies of 396.1keV and 802.0keV. It is attributed to a 13/2 + state at E
* = 1198.1 keV.PACS:
23.60. + e
decay - 27.90. + b
相似文献
42.
We answer a known question showing that not all radicals of semigroup Q algebras
of Q0 -complete commutative, cancellative and torsion-free semigroups
are homogeneous. 相似文献
43.
The spectral function of the scalar-isoscalar channel of the O(N) symmetric linear σ model is studied in the broken symmetry phase. The investigation is based on the leading order evaluation of the self-energy in the limit of large number of Goldstone bosons. We describe its temperature-dependent variation in the whole low temperature phase. This variation closely reflects the trajectory of the scalar-isoscalar quasi-particle pole. In the model with no explicit chiral symmetry breaking, we studied also the corresponding dynamical exponent near the critical point. 相似文献
44.
J.A. Fülöp Zs. Major B. Horváth F. Tavella A. Baltuška F. Krausz 《Applied physics. B, Lasers and optics》2007,87(1):79-84
The use of temporally shaped pump pulses for optical parametric chirped-pulse amplification can increase the efficiency and
suppress possible spectral distortions in this process. With this goal in mind a novel method for shaping narrowband picosecond
pulses has been developed. The method is based on the pulse stacking principle, where replicas of the incoming pulse are created
in a specially designed four-beam interferometer. The replicas are recombined with appropriate relative delays. The interferometer
design allows for a unique flexibility in varying the pulse shape, since all relevant degrees of freedom, such as relative
intensities and delays between the pulse replicas are independently adjustable. Here we describe the design of our device
in detail and report on the experimental demonstration of its pulse-shaping capabilities.
PACS 42.65.Yj; 42.65.Re; 42.81.Gs 相似文献
45.
A simple model consisting of two electronic levels and one vibrational mode (phonon) was theoretically studied. The electronic-vibrational interaction was linear in the vibrational displacement. The vibrational mode was taken in the harmonic approximation and was attached to the thermal bath formed by the ambient environment. The kinetic constants of the vibrational dissipation were of the second order in the vibrational-bath coupling and were taken in the Markovian limit. Although, depending on the parameters of the model, different curves of the non-radiative vibration-induced excited state decay were obtained, in general, three time intervals, corresponding to different physical behaviour, were found. In the short-time interval, small oscillations superimposed on the excited state decay were observed. They were determined by the vibrational frequency and influenced by electronic-vibrational coupling. In the middle-time interval, almost quasi-exponential decay was detected; its rate constant increased with stronger electronic-vibrational interaction and speed of vibrational relaxation. In the long-time interval, the decay was very slow and, under special conditions, even an asymptotic non-zero excited state population was observed. Its value increased with the strength of the off-diagonal electron-vibrational coupling. Links of the parameters of the model with quantum chemical terms were estimated. 相似文献
46.
In contrast with earlier literature data [7], both acrylic esters and acrylonitrile underwent Michael addition to l-methyl-3,4-dihydroisoquinolines 1-4 to yield the diesters 5-9 or the dinitrile 10 , respectively. Compounds 5-10 were converted by Claisen condensation to 1-[(3′-methoxycarbonyl- or 1-[(3′-ethoxycarbonyl-4′-oxo)-l'-cyclohexyl]-3,4-dihydroisoquinoline derivatives 11-16 . Several derivatives of 12 were prepared. The new compounds possess various pharmacological actions. 相似文献
47.
Radovan Hynek Iva Michalus Pavel Cejnar Jiří Šantrůček Sabina Seidlová Štěpánka Kučková Petra Sázelová Václav Kašička 《Electrophoresis》2021,42(23):2552-2562
Proteomic characterization of alveolar bones in oral surgery represents an analytical challenge due to their insoluble character. The implementation of a straightforward technique could lead to the routine use of proteomics in this field. This work thus developed a simple technique for the characterization of bone tissue for human maxillary and mandibular bones. It is based on the direct in-bone tryptic digestion of proteins in both healthy and pathological human maxillary and mandibular bone samples. The released peptides were then identified by the LC-MS/MS. Using this approach, a total of 1120 proteins were identified in the maxillary bone and 1151 proteins in the mandibular bone. The subsequent partial least squares–discrimination analysis (PLS-DA) of protein data made it possible to reach 100% discrimination between the samples of healthy alveolar bones and those of the bone tissue surrounding the inflammatory focus. These results indicate that the in-bone protein digestion followed by the LC-MS/MS and subsequent statistical analysis can provide a deeper insight into the field of oral surgery at the molecular level. Furthermore, it could also have a diagnostic potential in the differentiation between the proteomic patterns of healthy and pathological alveolar bone tissue. Data are available via ProteomeXchange with the identifier PXD026775. 相似文献
48.
The kinetics of free-radical cross-linking polymerization of methyl methacrylate (MM) in the presence of poly[2-(10-undecenoyloxy)ethyl methacrylate] (PUDEM) as a macromolecular cross-linker has been isothermally examined within the temperature range from 85–100°C using the differential scanning calorimetry (DSC). The activation energy found for this reaction, E
a=89.3 kJ mol–1, exceeds slightly the literature values of activation energy obtained for the mass polymerization of MM without any cross-linking agent. The activation energy has been also determined by the isoconversion method. It has been found that E
a decreases with the increase in the conversion, which may indicate a change in the reaction mechanism.This work was partly supported by the Committee for Research (KBN) in the framework of project No. 7 T08E 026 20 相似文献
49.
Hybrid organic-inorganic coatings and free-standing films made from [3-(glycidyloxy)propyl]trimethoxysilane, amino-terminated poly(oxypropylene) (Jeffamine D-230), colloidal polyaniline nanoparticles and, in some cases, colloidal nanosilica were prepared and characterized. HCl or 4-methylbenzene-1-sulfonic acid were used as catalysts for the sol-gel process and pH tuning, water-propan-2-ol mixture as a solvent. Electrical and mechanical properties and surface morphology of films were studied. The coatings were blue and non-conducting, or green and conducting, depending on preparation conditions. They have a smoother surface than in-situ polymerized polyaniline films. 相似文献
50.
István Ilisz Zoltán Pataj Róbert Berkecz Aleksandra Misicka Dagmara Tymecka Ferenc Fülöp Hee Jung Choi Myung Ho Hyun Antal Péter 《Journal of chromatography. A》2010,1217(7):1075-1082
Reversed-phase high-performance liquid chromatographic methods were developed for the separation of enantiomers of eleven unnatural β2-amino acids on a new chiral stationary phase, using the 11-methylene-unit spacer of aminoundecylsilica gel for the bonding of (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid as selector. The nature and concentration of the acidic and organic modifiers, the pH, the mobile phase composition, and the structures of the analytes substantially influenced the retention and resolution. Separations were carried out at constant mobile phase compositions in the temperature range 7–40 °C and the changes in enthalpy, Δ(ΔH°), entropy, Δ(ΔS°), and free energy, Δ(ΔG°) were calculated. The elution sequence was determined in some cases: the S enantiomers eluted before the R enantiomers. 相似文献