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51.
We study charmed baryon resonances that are generated dynamically from a coupled-channel unitary approach that implements heavy-quark symmetry. Some states can already be identified with exper-imental observations, such as Λ_c(2595), Λ_c(2660), Σ_c(2902) or Λ_c(2941), while others need a compilation of more experimental data as well as an extension of the model to include higher order contributions. We also compare our model to previous SU(4) schemes. 相似文献
52.
Salcedo D 《The journal of physical chemistry. A》2006,110(44):12158-12165
Tropospheric aerosols are usually complex mixtures of inorganic and organic components. Although the thermodynamic properties of inorganic aerosols have been widely studied, the effect of organics on such properties is still under discussion. In this study, solubility in water, water activity (a(w)) of aqueous solutions, deliquescence relative humidity (DRH), eutonic composition, and eutonic DRH were determined for bulk mixtures of malonic acid (MA) with ammonium sulfate (AS) and ammonium bisulfate (ABS) at 25 degrees C over the full range of composition (from 0 wt % to the solubility limit of the mixture components). The data were used to construct equilibrium phase diagrams, which show the phase of the mixtures as a function of total composition, dry mixture composition, water content, and ambient relative humidity (RH). This work complements previous reports on the thermodynamic properties of AS/MA mixtures because the range of concentrations investigated is larger than in any other published single study. On the other hand, this is the first report on the a(w), deliquescence, and water absorption of ABS/MA mixtures. The eutonic composition for AS/MA mixtures was found to be 66.8 MA dry wt % (MA dry wt % = MA mass x 100/(AS mass + MA mass) with a DRH of 0.437. The eutonic composition for the ABS/MA mixtures was lower than for the AS/MA mixtures: 20.9 MA dry wt % with a DRH of 0.327. Measured a(w) of liquid AS/MA and ABS/MA solutions is compared with an extended Zdanovskii-Stokes-Robinson expression, obtaining a good agreement (error < 5-6%). The expression was used to predict water uptake of mixtures and might be useful to interpret particle hygroscopic growth experiments. Comparison of the AS/MA and ABS/MA systems indicates that ABS reduces the DRH and enhances water uptake, relative to mixtures with AS. The results confirm that ambient particles containing sulfate and water-soluble organic compounds can remain liquid or partially liquid at very low ambient RH conditions, especially if the sulfate is not completely neutralized. 相似文献
53.
The dimension two gluon condensate has been used previously within a simple phenomenological model to describe power corrections
from available lattice data for the renormalized Polyakov loop and the heavy quark-antiquark free energy in the deconfined
phase of QCD [1,2]. The QCD trace anomaly of gluodynamics also shows unequivocal inverse temperature power corrections which
may be encoded as dimension two gluon condensate. We analyze lattice data of the trace anomaly and compare with other determinations
of the condensate from previous references, yielding roughly similar numerical values. 相似文献
54.
Dr. Christian B. Nielsen Dr. Theis Brock‐Nannestad Dr. Peter Hammershøj Dr. Theis K. Reenberg Dr. Magnus Schau‐Magnussen Denis Trpcevski Thomas Hensel Dr. Roberto Salcedo Gleb V. Baryshnikov Prof. Boris F. Minaev Dr. Michael Pittelkow 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(12):3898-3904
We describe herein the first synthesis of a new class of anti‐aromatic planar cyclooctatetraenes: the azatrioxa[8]circulenes. This was achieved by treating a suitably functionalised 3,6‐dihydroxycarbazole with 1,4‐benzoquinones or a 1,4‐naphthoquinone. We fully characterised the azatrioxa[8]circulenes by using optical, electrochemical and computational techniques as well as by single‐crystal X‐ray crystallography. The results of a computational study (NICS) suggest that the central planar cyclooctatetraene is anti‐aromatic when the molecules are in neutral or oxidised states (2+), and that the corresponding dianions are aromatic. We discuss the aromatic/anti‐aromatic nature of the planar cyclooctatetraenes and compare them with the isoelectronic tetraoxa[8]circulenes. 相似文献
55.
L. L. Salcedo 《Physics letters. [Part B]》2002,530(1-4):244-250
It is argued that the derivative expansion is a suitable method to deal with finite temperature field theory, if it is restricted to spatial derivatives only. Using this method, a simple and direct calculation is presented for the radiatively induced Chern–Simons-like piece of the effective action of (2+1)-dimensional fermions at finite temperature coupled to external gauge fields. The gauge fields are not assumed to be subjected to special constraints, and in particular, they are not required to be stationary nor Abelian. 相似文献
56.
57.
L. A. M. Salcedo J. P. B. C. de Melo D. Hadjimichef T. Frederico 《The European Physical Journal A - Hadrons and Nuclei》2006,27(2):213-223
We study the scaling of the 3S1-1S0 meson mass splitting and the pseudoscalar weak-decay constants with the mass of the meson, as seen in the available experimental
data. We use an effective light-front QCD-inspired dynamical model regulated at short distances to describe the valence component
of the pseudoscalar mesons. The experimentally known values of the mass splitting, decay constants (from global lattice-QCD
averages) and the pion charge form factor up to 4 [GeV/c]2 are reasonably described by the model. 相似文献
58.
Predominant Information Quality Scheme for the Essential Amino Acids: An Information‐Theoretical Analysis
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Prof. Rodolfo O. Esquivel Dr. Moyocoyani Molina‐Espíritu Prof. Sheila López‐Rosa Prof. Catalina Soriano‐Correa Prof. Carolina Barrientos‐Salcedo Prof. Miroslav Kohout Prof. Jesús S. Dehesa 《Chemphyschem》2015,16(12):2571-2581
In this work we undertake a pioneer information‐theoretical analysis of 18 selected amino acids extracted from a natural protein, bacteriorhodopsin (1C3W). The conformational structures of each amino acid are analyzed by use of various quantum chemistry methodologies at high levels of theory: HF, M062X and CISD(Full). The Shannon entropy, Fisher information and disequilibrium are determined to grasp the spatial spreading features of delocalizability, order and uniformity of the optimized structures. These three entropic measures uniquely characterize all amino acids through a predominant information‐theoretic quality scheme (PIQS), which gathers all chemical families by means of three major spreading features: delocalization, narrowness and uniformity. This scheme recognizes four major chemical families: aliphatic (delocalized), aromatic (delocalized), electro‐attractive (narrowed) and tiny (uniform). All chemical families recognized by the existing energy‐based classifications are embraced by this entropic scheme. Finally, novel chemical patterns are shown in the information planes associated with the PIQS entropic measures. 相似文献
59.
C. Garcıa-Recio J. Nieves L. L. Salcedo 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):491-494
The construction of an extended version of the Weinberg-Tomozawa Lagrangian, in which baryons and mesons form spin-flavor
multiplets, is reviewed and some of its properties discussed, for an arbitrary number of colors and flavors. The coefficient
tables of spin-flavor irreducible representations related by crossing between the s-, t- and u-channels are explicitly constructed. 相似文献
60.
We developed a detailed rate equation model to study laser dynamics and active Q-switching in Tm,Ho: YAG and Tm:YAG lasers. The simulation results agreed well with published experimental data, as well as
provided new insights for optimizing pulse generation.
Received: 7 March 1996/Accepted: 28 May 1996 相似文献