Existence and Well-Posedness for Symmetric Vector Quasi-Equilibrium Problems

An existence result for the solution set of symmetric vector quasi-equilibrium problems that allows for discontinuities is obtained. Moreover, sufficient conditions for the generalized Levitin-Polyak well-posedness of symmetric vector quasi-equilibrium problems are established

One-Pot Synthesis of N,N′-dialkylureas via Carbonylation of Amines with CO2 Applying Y0.08Zr0.92O1.96 Mixed Oxide (YSZ-8) as a Heterogeneous Catalyst

One-pot synthesis of N,N′-dialkylureas were successfully achieved from catalytic carbonylation of aliphatic primary amines with CO2 as the carbon source and Y0.08Zr0.92O1.96 mixed oxide (Yttria-stabilized zirconia, YSZ-8) as the heterogeneous catalyst. The yield of the target product was obtained up to 80.60% from a 48 h reaction with an aliphatic primary amine and 3.0 MPa CO2 in N-methyl-2-pirrolidinone at 160 °C. A multi-pronged mechanistic study was carried out where factors that might influence the reaction efficiency were studied, including catalyst structure, substrates basicity, CO2 pressure, solvent polarity and reaction time. The presence of oxygen vacancies in YSZ-8 was found to be essential for the carbonylation process by creating additional reduction potential for the activation of CO2 which would lead to the key intermediate species

Temperature effect on screening effects and stopping power for low-energy d-

In order to investigate the interaction of d-Li, the excitation functions of α-particle yields for the 6Li(d, α)4He reaction in liquid Li (495–600 K) have been measured for the bombarding energies from 30 to 70 keV by 2.5 keV steps. It turns out that the excitation function is significantly affected by the environmental temperature, and this results in a negative T-dependence for both screening potential and energy loss. The T-dependence of the screening energy can be simply explained by the reduced Debye-Hueckel model due to the ionic screening, while the experimental evidence of the T-dependence energy loss is presented only for calling a more reasonable explanation

Heterogeneous CPU-GPU Accelerated Subgridding in the FDTD Modelling of Microwave Breakdown

Microwave breakdown is crucial to the transmission of high-power microwave (HPM) devices, where a growing number of studies have analyzed the complex interactions between electromagnetic waves and the evolving plasma from theoretical and analytical perspectives. In this paper, we propose a finite-difference time-domain (FDTD) scheme to numerically solve Maxwell’s equation, coupled with a fluid plasma equation for simulating the plasma formation during HPM air breakdown. A subgridding method is adopted to obtain accurate results with lower computational resources. Moreover, the three-dimensional subgridding Maxwell–plasma algorithm is efficiently accelerated by utilizing heterogeneous computing technique based on graphics processing units (GPUs) and multiple central processing units (CPUs), which can be applied as an efficient method for the investigation of the HPM air breakdown phenomena

Investigation on the interface bonding and reinforcement mechanism of nano Ti/AZ31 magnesium matrix composites

In this study, nano Ti/AZ31 composites were successfully prepared by powder metallurgy method, and the strength and plasticity of the composites were improved in both directions. The SEM shows that the Ti particles were evenly distributed at the grain boundary in the sintered composite, and the Ti particles pin the grain boundary to make the grain of the composite significantly refined. EBSD shows that the addition of nano Ti particles significantly reduces the texture strength of the composite and increases the starting probability of the slip system. TEM shows that nano Ti and AZ31 matrix formed stable Al3Ti and MgO phases at the interface, and shows a strong coherent relationship. The nanoindentation test shows that the Ti/AZ31 interface of the composite was stable, the interface bonding energy and interface fracture toughness were gradiently distributed, and the bonding energy and fracture toughness of the interface bonding area were better than those of the matrix. Tensile test shows that the 1.5 wt%Ti/AZ31 composite obtained the best comprehensive mechanical properties with yield strength, ultimate tensile strength and elongation of 143 MPa, 243 MPa and 11.5%, respectively, obviously higher than those of AZ31 alloys. The increased strength was mainly due to the grain refinement and strengthening at grain boundaries. The improved ductility was the result of weakened texture, increase of slip system start-up probability and strong interfacial bonding between Ti particles and AZ31 matrix

Direct measurement of astrophysical factor S(E) and screening potential for Be9(p,α)6Li reaction at low energy

As Beryllium is an important element in primary nucleosynthesis, its nuclear reaction cross-sections induced by charged projectiles need to be measured precisely. The astrophysical S(Ei) factors were measured in the ultra-low energy range from Elab=18 to 100 keV in 2-keV increments (42 points). Both the astrophysical S(E) curve (Sbare(0)=16.2±1.8MeVb) and the screening energy (Us=545±98eV) were deduced. In regard to astrophysical applications of the Sbare(E) curve, the present results are consistent with Zahnow's direct measurement. For the long-standing problem of ‘abnormal’ screening effect, our screening energy result also agrees with that obtained using the Trojan-horse method (Us=676±86eV) but smaller than Zahnow's value (900±50eV), although all results are much larger than that obtained in the adiabatic limit (∼264 eV). Keywords: p–9Be reaction, Screening potential, Astrophysical facto

Highly Efficient and Reversible SO₂ Capture by Surfactant-Derived Dual Functionalized Ionic Liquids with Metal Chelate Cations

A series of dual functionalized ionic liquids with metal chelate cations from surfactant and alkali metal salt were designed, prepared, and used for SO₂ capture. The effect of metal ions, coordination number, anionic structures, temperature, and pressure on SO₂ absorption was investigated. The interaction of these functionalized ionic liquids with SO₂ was explained by spectroscopic investigation. The results showed that these metal-containing ionic liquids exhibited high absorption capacity through a combination of physical and chemical interaction of SO₂ with basic anions and ether-containing cations as well as excellent reversibility (21 recycles). Considering the easy preparation, low cost, and excellent performance, these dual functionalized metal-containing ionic liquids provide significant improvements over traditional ionic liquids, indicating the promise for industrial application in SO₂ capture

Coupled CRC 2D and ALI 3D Cultures Express Receptors of Emerging Viruses and Are More Suitable for the Study of Viral Infections Compared to Conventional Cell Lines

Infections of emerging and reemerging viruses (SARS-CoVs, influenza H1N1, etc.) largely and globally affect human health. Animal models often fail to reflect a physiological status because of species tropism of virus infection. Conventional cell lines are usually genetically and phenotypically different from primary cells. Developing an in vitro physiological model to study the infection of emerging viruses will facilitate our understanding of virus-host cell interactions, thereby benefiting antiviral drug discovery. In the current work, we first established normal airway epithelial cells (upper and lower airway track) in 2D and 3D culture systems using conditional reprogramming (CR) and air-liquid interface (ALI) techniques. These long-term cultures maintained differentiation potential. More importantly, these cells express two types of influenza virus receptors, α2-6-Gal- and α2-3-Gal-linked sialic acids, and angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoVs as well. These cells were permissive to the infection of pandemic influenza H1N1 (H1N1pdm). In contrast, the lung cancer cell line A549 and immortalized airway epithelial cells (16HBE) were not susceptible to H1N1 infection. A virus-induced cytopathic effect (CPE) on 2D CRC cultures developed in a time-dependent manner. The pathological effects were also readily observed spreading from the apical layer to the basal layer of the 3D ALI culture. This integrated 2D CRC and 3D ALI cultures provide a physiological and personalized in vitro model to study the infection of emerging viruses. This novel model can be used for studying virus biology and host response to viral infection and for antiviral drug discovery