Production of positronium, dimuonium, and ditauonium in ultra-peripheral heavy ion collisions with two-photon processes

We calculate the production of exotic electromagnetic bound systems, which ia an consisting of a ($l^{+}l^{-}$) bound state system such as positronium, dimuonium, and ditauonium, by photon-photon interaction with the equivalent photon approximation in ultra-peripheral heavy ion collisions considering the nuclear form factor. The numerical results demonstrate that the experimental study of positronium, dimuonium, and ditauonium in ultra-peripheral collisions is feasible at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies.Comment: 7 pages, 2 figure

Production of χc\chi_{c} and ηc\eta_{c} production in ultra-peripheral collisions with two-photon processes

We calculate the production of $\chi_{c}$ and $\eta_{c}$ by the semi-coherent and coherent two-photon interaction in ultra-peripheral heavy ion collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies. The differential cross section of transverse momentum distribution and rapidity distribution for $AB\stackrel{\gamma\gamma}{\longrightarrow}AHB$ (H=$\chi_{c}$ and $\eta_{c}$), are estimated by using the equivalent photon approximation in ultra-peripheral nucleus-nucleus collisions. The numerical results demonstrate that the experimental study of $\chi_{c}$ and $\eta_{c}$ in ultra-peripheral nucleus-nucleus collisions is feasible at RHIC and LHC energies.Comment: 6 pages, 2 figures. arXiv admin note: text overlap with arXiv:2209.1143

Preparation and ageing-resistant properties of polyester composites modified with functional nanoscale additives

This study investigated ageing-resistant properties of carboxyl-terminated polyester (polyethylene glycol terephthalate) composites modified with nanoscale titanium dioxide particles (nano-TiO(2)). The nano-TiO(2) was pretreated by a dry coating method, with aluminate coupling agent as a functional grafting additive. The agglomeration resistance was evaluated, which exhibited significant improvement for the modified nanoparticles. Then, the effects of the modified nano-TiO(2) on the crosslinking and ageing-resistant properties of the composites were studied. With a real-time Fourier transform infrared (FT-IR) measurement, the nano-TiO(2) displayed promoting effect on the crosslinking of polyester resin with triglycidyl isocyanurate (TGIC) as crosslinking agent. Moreover, the gloss retention, colour aberration and the surface morphologies of the composites during accelerated UV ageing (1500 hours) were investigated. The results demonstrated much less degree of ageing degradation for the nanocomposites, indicating an important role of the nano-TiO(2) in improving the ageing-resistant properties of synthetic polymer composites

The REST Gene Signature Predicts Drug Sensitivity in Neuroblastoma Cell Lines and Is Significantly Associated with Neuroblastoma Tumor Stage

Neuroblastoma is the most common and deadly solid tumor in children, and there is currently no effective treatment available for neuroblastoma patients. The repressor element-1 silencing transcription (REST) factor has been found to play important roles in the regulation of neural differentiation and tumorigenesis. Recently, a REST signature consisting of downstream targets of REST has been reported to have clinical relevance in both breast cancer and glioblastoma. However it remains unclear how the REST signature works in neuroblastoma. Publicly available datasets were mined and bioinformatic approaches were used to investigate the utility of the REST signature in neuroblastoma with both preclinical and real patient data. The REST signature was found to be associated with drug sensitivity in neuroblastoma cell lines. Further, neuroblastoma patients with enhanced REST activity are significantly associated with higher clinical stages. Loss of heterozygosity on chromosome 11q23, which occurs in a large subset of high-risk neuroblastomas, tends to be correlated with high REST activity, with marginal significance. In conclusion, the REST signature has important implications for targeted therapy, and it is a prognostic factor in neuroblastoma patients

Effect of oxygen coordination environment of Ca-Mn oxides on catalytic performance of Pd supported catalysts for aerobic oxidation of 5-hydroxymethyl-2-furfural

This work was supported by Natural Science Foundation of Tianjin (Grant No. 17JCYBJC22600) and the Fundamental Research Funds for the Central Universities. Computational support was provided by the Beijing Computing Center (BCC).Four types of Ca-Mn oxides, including CaMnO3, CaMn2O4, CaMn3O6 and Ca2Mn3O8, have been prepared and used as supports for Pd nanoparticles. The oxygen activation capacity of these oxides and the catalytic activity of the oxide supported Pd nanocatalysts have been investigated using the aerobic oxidation of 5-hydroxymethyl-2-furfural as a model reaction. It is found that the local coordination environment of lattice oxygen sites plays a crucial role on their redox property and charge transfer ability from Pd nanoparticles to the support. In particular, the Ca-Mn oxide with lower oxygen coordination number, weaker metal-oxygen bonds and tunnel crystal structure, e.g. CaMn2O4, exhibits promoted oxygen activation capacity, and stronger electron transfer ability. Consequently, Pd/CaMn2O4 exhibits the highest catalytic activity among these catalysts, providing a promising yield of 2,5-furandicarboxylic acid. This work may shed light on the future investigation on the design of local structure of active oxygen sites in oxides or oxide supported catalysts for redox reactions.PostprintPeer reviewe

Spin-density-wave transition in double-layer nickelate La3Ni2O7

Recently, a signature of high-temperature superconductivity above the liquid nitrogen temperature (77 K) was reported for La3Ni2O7 under pressure. This finding immediately stimulates intense interest in the possible high-Tc superconducting mechanism in double-layer nickelates. Interestingly, the pressure-dependent phase diagram inferred from transport measurements indicates that superconductivity under high pressure emerges from the suppression of a density-wave-like transition at ambient pressure, which is similar to high-temperature superconductors. Therefore, clarifying the exact nature of the density-wave-like transition is important for determining the mechanism of superconductivity in double-layer nickelates. Here, nuclear magnetic resonance (NMR) spectroscopy of 139La nuclei was performed to study the density-wave-like transition in a single crystal of La3Ni2O7. The temperature-dependent 139La NMR spectrum and nuclear spin-lattice relaxation rate (1/T1) provide unambiguous evidence for a spin-density-wave (SDW) transition with a transition temperature TSDW of ~ 150 K. Furthermore, the anisotropic splitting of the NMR spectrum suggests a possible double spin stripe with magnetic moments along the c axis. In addition, the present NMR measurements also revealed spatial inhomogeneity of magnetism due to inner apical oxygen vacancies. All these results will be helpful for building a connection between superconductivity and magnetic interactions in double-layer nickelates.Comment: 14 pages, 4 figure