Properties and structure of N = Z nuclei within relativistic mean field theory

The axially deformed relativistic mean field theory with the force NLSH has been performed in the blocked BCS approximation to investigate the proper-ties and structure of N=Z nuclei from Z=20 to Z=48. Some ground state quantities such as binding energies, quadrupole deformations, one/two-nucleon separation energies, root-mean-squaxe (rms) radii of charge and neutron, and shell gaps have been calculated. The results suggest that large deformations can be found in medium-heavy nuclei with N=Z=38-42. The charge and neutron rms radii increase rapidly beyond the magic number N=Z=28 until Z=42 with increasing nucleon number, which is similar to isotope shift, yet beyond Z=42, they decrease dramatically as the structure changes greatly from Z=42 to Z=43. The evolution of shell gaps with proton number Z can be clearly observed. Besides the appearance of possible new shell closures, some conventional shell closures have been found to disappear in some region. In addition, we found that the Coulomb interaction is not strong enough to breakdown the shell structure of protons in the current region.

Investigation of two-proton emission from excited states of the odd-Z nucleus P-28 by complete-kinematics measurements

An experiment to study exotic two-proton emission from excited levels of the odd-Z nucleus P-28 was performed at the National Laboratory of Heavy Ion Research-Radioactive Ion Beam Line (HIRFL-RIBLL) facility. The projectile P-28 at the energy of 46.5 MeV/u was bombarding a Au-197 target to populate the excited states via Coulomb excitation. Complete-kinematics measurements were realized by the array of silicon strip detectors and the CsI + PIN telescope. Two-proton events were selected and the relativistic-kinematics reconstruction was carried out. The spectrum of relative momentum and opening angle between two protons was deduced from Monte Carlo simulations. Experimental results show that two-proton emission from P-28 excited states less than 17.0 MeV is mainly two-body sequential emission or three-body simultaneous decay in phase space. The present simulations cannot distinguish these two decay modes. No obvious diproton emission was found.

A novel approach to isoscaling: The role of the order parameter m = N-f-Z(f)/A(f)

Isoscaling is derived within a recently proposed modified Fisher model where the free energy near the critical point is described by the Landau O(m(6)) theory. In this model m = N-f-Z(f)/A(f) is the order parameter, a consequence of (one of) the symmetries of the nuclear Hamiltonian. Within this framework we show that isoscaling depends mainly on this order parameter through the 'external (conjugate) field' H. The external field is just given by the difference in chemical potentials of the neutrons and protons of the two sources. To distinguish from previously employed isoscaling relationships, this approach is dubbed: m-scaling. We discuss the relationship between this framework and the standard isoscaling formalism and point out some substantial differences in interpretation of experimental results which might result. These should be investigated further both theoretically and experimentally. (C) 2010 Elsevier B.V. All rights reserved.

Two-electron-one-photon M1 and E2 transitions between the states of the 2p(3) and 2s(2)2p odd configurations for B-like ions with 18 <= Z <= 92

Two-electron-one-photon (TEOP) M1 and E2 transition energies, line strengths and transition probabilities between the states of the 2p(3) and 2s(2)2p odd configurations for B-like ions with 18 <= Z <= 92 have been calculated using the GRASP2K package based on the multiconfiguration Dirac-Hartree-Fock (MCDHF) method. Employing active-space techniques to expand the configuration list, we have systematically considered the valence, core-valence and core-core electron correlation effects. Breit interaction and quantum electrodynamical (QED) effects were also included to correct atomic state wavefunctions and the corresponding energies. Influences of electron correlation, Breit interaction and QED effects on transition energies and line strengths of the TEOP M1 and E2 transitions were analysed in detail. The present results were also compared with other theoretical and experimental values.

Relativistic Mean Field Study of the Z=117 Isotopic Chain

The properties of the Z = 117 isotopic chain are studied within the framework of the axially deformed relativistic mean field theory (RMFT) in the blocked BCS approximation. The ground-state properties, such as binging energies, deformations as well as the possible.. decay energies and lifetimes are calculated with the parameter set of NL-Z2 and compared with results from the finite range droplet model. The analysis by RMFT shows that the isotopes in the range of mass number A = 291 similar to 300 exhibit higher stability, which suggests that they may be promising nuclei to be hopefully synthesized in the lab among the nuclei Z = 117.

(Z)-2-(2-chloro-3,3,3-trifluoroprop-1enyl)-6-methoxyphenyl acetate

The crystal structure of the title compound, C12H10ClF3O3, was determined in order to establish the configuration of the C double bond. The compound was found to be the Z isomer. The crystal structure is dominated by Cl center dot center dot center dot O halogen bonds [Cl center dot center dot center dot O = 3.111 (3) angstrom], as well as C-H center dot center dot center dot O and C-H center dot center dot center dot F hydrogen-bonding interactions, that connect neighboring molecules into a three-dimensional supramolecular network.

N-Acetyl-N-{2-[(Z)-2-chloro-3,3,3-trifluoroprop-1-enyl]phenyl}acetamide

The title compound, C13H11ClF3NO2, adopts a Z conformation. Halogen center dot center dot center dot oxygen interactions [Cl center dot center dot center dot O = 2.967 (3) angstrom] in the crystal packing lead to the formation of a dimer joined by two Cl center dot center dot center dot O bonds.

Self-Assembly of Hyperbranched Multiarmed PEG-PEI-PLys(Z) Copolymer into Micelles, Rings, and Vesicles

Self-assembling of synthesized novel biodegradable hyperbranched amphiphilic poly(ethylene glycol)-polyethylenimine-poly(epsilon-benzyloxycarbonyl-L-lysine) (PEG-PEI-PLys(Z)) in aqueous media is studied. In aqueous media. PLys(Z) is the hydrophobic segment, with PEG and PEI as the hydrophilic segments. It will self-assemble into spherical shape when the selected solvent water is dropped into the common solvent tetrahydrofuran (THF). And when PEG-PEI-PLYS in common solvent is dropped into mixed solvent water and THF, rings will come into King. The spherical and rings are observed by environmental scanning electron microscopy (ESEM) and transmission electron microscopy ITEM). It shows that the size of the sphere is about 100 nm, and the diameter of ring distributes from 400 nm to 10 mu m and bigger with the time roll around.

Reversible B/Z-DNA transition under the low salt condition and non-B-form polydApolydT selectivity by a cubane-like europium-L-aspartic acid complex

We report here that a cubane-like europium-L-aspartic acid complex at physiological pH can discriminate between DNA structures as judged by the comparison of thermal denaturation, binding stoichiometry, temperature-dependent fluorescence enhancement, and circular dichroism and gel electrophoresis studies. This complex can selectively stabilize non-B-form DNA polydApolydT but destabilize polydGdCpolydGdC and polydAdTpolydAdT. Further studies show that this complex can convert B-form polydGdCpolydGdC to Z-form under the low salt condition at physiological temperature 37 degrees C, and the transition is reversible, similar to RNA polymerase, which turns unwound DNA into Z-DNA and converts it back to B-DNA after transcription. The potential uses of a left-handed helix-selective probe in biology are obvious. Z-DNA is a transient structure and does not exist as a stable feature of the double helix. Therefore, probing this transient structure with a metal-amino acid complex under the low salt condition at physiological temperature would provide insights into their transitions in vivo and are of great interest.

用Z-扫描技术研究手性介质非线性圆双折射

用Z 扫描技术研究了各向同性手性介质 (聚酯酰亚胺吡啶溶液 )对于左、右圆偏振光的非线性圆双折射 ,得到在低光强下非线性旋光角的变化规律 ,验证了非线性圆双折射与非线性旋光的关系。

镍催聚1,4-聚丁二烯橡胶的e_y,[Z]和f值与其内在的相关性

比较稀土催聚1，4—聚丁二烯橡胶和几种不同温度下聚合的镍催聚1，4—聚丁二烯橡胶的σｙ 和［η］，从中得知链缠结的变化是影响σｙ 和［η］以及 τ的主要原因，而微观结构的变化可能是影响链缠结的因素之一，1，4—聚丁二烯橡胶的加工性能与链缠结有关。

Synthesis, crystal structure and properties of (Z)-3-triphenylstannyl-1,1-diphenyl propenol

Five new organotin compounds were synthesized and characterized, X-ray crystal structure analysis of (Z)-3-triphenylstannyl-1,1-diphenyl propenol was performed, The crystal belongs to space group P2(1)/n. The cell parameters are: a = 1.235 7(2) nm, b = 0.987 4(2) nm, c = 2.208 1(4) nm, beta = 95.23(3)degrees, V = 2.683 0(9) nm(3), Z = 4, R = 0.027 9, R-w = 0.064 5. The tin atom of the molecule exists in a distorted tetrahedron, Z isomer of double bond is obtained.

(Z)-3-三苯基锡基-1,1-二苯基烯丙醇的合成、晶体结构和性质研究

合成并表征了５种新的有机锡化合物．测定了（Ｚ）－３－三苯基锡基－１，１－二苯基烯丙醇的晶体结构．晶体属于Ｐ２１／ｎ空间群，晶胞参数ａ＝１．２３５７（３）ｎｍ，ｂ＝０．９８７４（２）ｎｍ，ｃ＝２．２０８１（２）ｎｍ，β＝９５．２３（３）°，Ｚ＝４．分子结构是以锡为中心的畸变四面体构型，双键为顺式构型．并对其性质进行了研究.