Reevaluation of the density dependence of nucleon radius and mass in the global color symmetry model of QCD

With the global color symmetry model (GCM) at finite chemical potential, the density dependence of the bag constant, the total energy and the radius of a nucleon in nuclear matter is investigated. A relation between the nuclear matter density and the chemical potential with the action of QCD being taken into account is obtained. A maximal nuclear matter density for the existence of the bag with three quarks confined within is given. The calculated results indicate that, before the maximal density is reached, the bag constant and the total energy of a nucleon decrease, and the radius of a nucleon increases slowly, with the increasing of the nuclear matter density. As the maximal nuclear matter density is reached, the mass of the nucleon vanishes and the radius becomes infinite suddenly. It manifests that a phase transition from nucleons to quarks takes place.Comment: 18 pages, 3 figure

The Sand Removal Performance and Erosion Characteristics of Shale Gas Wellhead Desander

In the process of shale gas extraction, fracturing technology is often used, and the extracted gas contains large amounts of sand, resulting in the risk of blockage and erosion of surface gathering equipment, which seriously affects safe production. To address this problem, this paper presents a numerical study of the sand removal performance and erosion characteristics of the filter desander used in Sichuan shale gas fields under different operating conditions (flow velocity, sand mass flow rate, operating pressure, and sand particle size) using CFD method. The results show that the increase of shale gas velocity is not conducive to the efficient operation of the filter desander. So the flow velocity should be controlled within 10 m/s as much as possible to avoid the rapid drawdown of separation efficiency and overly high erosion rate. When the sand size increases from 10μm to 100μm, the erosion area of the filter desander changes to sheet-like distribution, and the separation efficiency increases to 85%, a 2.3-fold increase. In addition, the change in operating pressure has a relatively small impact on the erosion wear of the desander

1,3-Bis[(4-methylbenzylidene)amino­oxy]propane

The title bis­oxime compound, C19H22N2O2, synthesized by the reaction of 4-methyl-2-hydroxy­benzaldehyde with 1,3-bis­(amino­oxy)propane in ethanol, adopts a V-shaped conformation. The dihedral angle between the rings is 84.59 (3)°. The mol­ecule is disposed about a crystallographic twofold rotation axis, with one C atom lying on the axis. In the crystal, mol­ecules are packed by C—H⋯π(Ph) inter­actions, forming chains

4-({4-[1-(Methoxy­imino)eth­yl]anilino}(phen­yl)methyl­ene)-3-methyl-2-phenyl-1H-pyrazol-5(4H)-one

In the title compound, C26H24N4O2, the dihedral angles between the central pyrazole ring and the other three benzene rings are 40.02 (3), 77.51 (5) and 55.72 (3)°. A strong intra­molecular N—H⋯O hydrogen bond forms a six-membered ring with an S(6) motif. In the crystal structure, a weak inter­molecular C—H⋯N inter­action with graph-set motif R 2 2(8) and C—H⋯O hydrogen bonds link each mol­ecule to three others, forming an infinite two-dimensional supra­molecular structure

(E)-2-{4-[1-(Hydroxyimino)ethyl]phenyl­iminomethyl}-6-methoxyphenol mono­hydrate

In the title compound, C16H16N2O3·H2O, the benzene rings are nearly coplanar with each other, forming a dihedral angle of 4.46 (3)°. There is a strong intra­molecular O—H⋯N hydrogen bond which results in a six-membered ring. In the crystal, the mol­ecules are connected into a three-dimensional network via O—H⋯O and O—H⋯N inter­molecular hydrogen bonds, forming a centrosymmetric ring along the b axis with graph-set motif R 4 4(10). In addition, the short distances between the centroids of six-membered rings [3.555 (1) Å], indicate the existence of π–π stacking inter­actions, which may stabilize the crystal structure