1,549 research outputs found
Cyclic Sulfones from Double Conjugate Addition of Rongalite
We report a cyclic sulfone synthesis method from the addition of sodium hydroxymethanesulfinate to doubly electrophilic dienone substrates. The novel synthesis of the cyclic sulfone thus avoided the using the toxic and odorous sulfides, and also oxidizing reagents. We prepared both the symmetrical and unsymmetrical substrates, and then used the substrate for the synthesis of cyclic sulfone
Preliminary Analysis of YANG Changji’s Thoughts on Ethics
Yang Changji is a famous educator and ethicist in modern time. His ethics thought combines the West and Eastern ethics as a whole, gathering each school’s advantages. This paper makes a preliminary study on the ethics thought of Yang Changji, summarizes the main content of his ideas, evaluates its ideological value, and criticizes the deficiency. Moreover, it analyses the effect of his thoughts on Mao Zedong and other revolutionists
Crystal structure of 3-methyl-2,3-dihydro-2-thioxoquinazolin-4(1H)-one, C9H8N2OS
Abstract
C9H8N2OS, monoclinic, C2/c (no. 15), a = 24.273(5) Å, b = 9.026(2) Å, c = 8.2852(19) Å, β = 108.818(4)°, V = 1718.2(7) Å3, Z = 8, R
gt(F) = 0.0438, wR
ref(F
2) = 0.1190, T = 296(2) K
The Wigner solution of quark gap equation at nonzero current quark mass and partial restoration of chiral symmetry at finite chemical potential
According to the generally accepted phase diagram of QCD, at low temperature
and high baryon number density the chiral phase transition of QCD is of first
order and the co-existence of the Nambu-Goldstone phase and the Wigner phase
should appear. This is in conflict with the usual claim that the quark gap
equation has no Wigner solution in the case of nonzero current quark mass. In
this paper we analyze the reason why the Wigner solution does not exist in the
usual treatment and try to propose a new approach to discuss this question. As
a first step, we adopt a modified Nambu-Jona-Lasinio (NJL) model to study the
Wigner solution at finite current quark mass. We then generalize this approach
to the case of finite chemical potential and discuss partial restoration of
chiral symmetry at finite chemical potential and compare our results with those
in the normal NJL model.Comment: 7 pages, 5 figures, and 1 table, discussion at finite chemical
potential adde
Terrace-like structure in the above-threshold ionization spectrum of an atom in an IR+XUV two-color laser field
Based on the frequency-domain theory, we investigate the above-threshold
ionization (ATI) process of an atom in a two-color laser field with infrared
(IR) and extreme ultraviolet (XUV) frequencies, where the photon energy of the
XUV laser is close to or larger than the atomic ionization threshold. By using
the channel analysis, we find that the two laser fields play different roles in
an ionization process, where the XUV laser determines the ionization
probability by the photon number that the atom absorbs from it, while the IR
laser accelerates the ionized electron and hence widens the electron kinetic
energy spectrum. As a result, the ATI spectrum presents a terrace-like
structure. By using the saddle-point approximation, we obtain a classical
formula which can predict the cutoff of each plateau in the terrace-like ATI
spectrum. Furthermore, we find that the difference of the heights between two
neighboring plateaus in the terrace-like structure of the ATI spectrum
increases as the frequency of the XUV laser increases
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