Numerical Prediciton of Heat Flux from Flame in Room Fire

A number of CFD (Computational Fluid Dynamics) calculations were carried out to simulate the large scale room corner fire, which is an important scenario for the evaluation of the fire performance of the surface lining material. Considered are turbulent gas flows, turbulent combustion, radiation and heat conduction inside solid boundary. Heat transfer from flame and hot gas is calculated, with the important radiation component presented by discrete transfer (DT) method and the convection heat transfer considered by the wall function. An absorptivity and emissivity model was employed to predict the radiation property of combustion products including soot, CO2 and H2O, which are usually the primary radiating species in the combustion of hydrocarbon fuels. Configurations are a square burner flame in the corner of the standard full scale fire room, with three different standoff distances: 0 cm, 5 cm and 10 cm, and two different burner outputs: 40 kW and 150 ItW. Totally, six cases were studied. The results, including the temperature and heat fluxes, are discussed and compared with experimental measurements

A Chattering Free Discrete-Time Global Sliding Mode Controller for Optoelectronic Tracking System

Aiming at the uncertainties including parameter variations and external disturbances in optoelectronic tracking system, a discrete-time global sliding mode controller (DGSMC) is proposed. By the design of nonlinear switching function, the initial state of control system is set on the switching surface. An adaptive discrete-time reaching law is introduced to suppress the high-frequency chattering at control input, and a linear extrapolation method is employed to estimate the unknown uncertainties and commands. The global reachability for sliding mode and the chattering-free property are proven by means of mathematical derivation. Numerical simulation presents that the proposed DGSMC scheme not only ensures strong robustness against system uncertainties and small tracking error, but also suppresses the high-frequency chattering at control input effectively, compared with the SMC scheme using conventional discrete-time reaching law

Investigation of Patch Antenna Based on Photonic Band-Gap Substrate with Heterostructures

The characteristics of the patch antenna based on photonic band-gap (PBG) substrate with heterostructures were studied numerically by using the method of finite difference time domain (FDTD). The results indicate that, comparing to the conventional patch antennas, the expansion of working frequency band of the new patch antenna can be realized and its radiation efficiency also can be improved notably with the influence of PBG. In addition, for this new kind of patch antenna, its return loss is much less and there are two minimum values for return loss corresponding to the resonant frequency of the two different photonic crystals made of the substrate. Its physical mechanism lies on the PBG which suppresses the surface waves propagating along the surface of the substrate and reflects most of electromagnetic wave energy radiated to the substrate significantly

B7-H4 Polymorphism Influences the Prevalence of Diabetes Mellitus and Pro-Atherogenic Dyslipidemia in Patients with Psoriasis.

BACKGROUND The co-inhibitory molecule B7-H4 is located in the genomic regions associated with type 1 diabetes (T1D) susceptibility. However, the correlation of B7-H4 with glycometabolism and dyslipidemia has never been studied. OBJECTIVE To explore the influence of B7-H4 polymorphism on the prevalence of diabetes mellitus (DM) and dyslipidemia in psoriasis. METHODS In this single-center cross-sectional study, we recruited 265 psoriatic patients receiving methotrexate (MTX) treatment. Thirteen single-nucleotide polymorphisms (SNPs) in B7-H4 were genotyped. Serum levels of total cholesterol (TC), triglycerides (TG), lipoprotein (a) (LP(a)), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein (LDL), apolipoprotein A1 (ApoA1), and apolipoprotein B (ApoB) were measured at baseline and week 12. RESULTS The GG genotype carriers of rs12025144 in B7-H4 had a higher prevalence of DM (57.14% vs. 17.71% vs. 18.67%, p = 0.0018), and had a poorer response to MTX in diabetic patients (p < 0.05), compared with AA or AG genotype carriers. The AG genotype of rs2066398 was associated with higher levels of pro-atherogenic lipids. MTX significantly downregulated the level of anti-atherogenic lipid ApoA1 in AA genotype carriers of rs2066398. CONCLUSIONS The genotypes rs12025144 and rs2066398 in B7-H4 were correlated with a higher prevalence of DM and dyslipidemia in psoriasis, respectively

Bis[μ-N-(3-meth­oxy-2-oxidobenzyl­idene-1:2κ2 O 2:O 2)-l-isoleucinato-2κ2 N,O]bis­(1,10-phenanthroline-1κ2 N,N′)dinickel(II) methanol tetra­solvate trihydrate

In the title complex, [Ni2(C14H17NO4)2(C12H8N2)2]·4CH3OH·3H2O, the two NiII ions are bridged by two Schiff base anions, leading to a dinuclear complex. One NiII ion is six-coordinated by four O atoms and two N atoms of two tridentate Schiff base ligands derived from the condensation of l-isoleucine and o-vanillin. The other NiII ion is six-coordinated by four N atoms of two 1,10-phenanthroline ligands and two O atoms of the Schiff base ligands. In the crystal, inter­molecular O—H⋯O and C—H⋯O hydrogen bonds lead to a three-dimensional structure. Intra­molecular C—H⋯O hydrogen bonds are also present. One of the methyl groups of the l-isoleucinate moieties is disordered over two sets of sites with an occupancy ratio of 0.687 (19):0.313 (19) and two methanol mol­ecules are half-occupied

Two-dimensional superconductivity at heterostructure of Mott insulating titanium sesquioxide and polar semiconductor

Heterointerfaces with symmetry breaking and strong interfacial coupling could give rise to the enormous exotic quantum phenomena. Here, we report on the experimental observation of intriguing two-dimensional superconductivity with superconducting transition temperature ($T_c$) of 3.8 K at heterostructure of Mott insulator Ti$_2$O$_3$ and polar semiconductor GaN revealed by the electrical transport and magnetization measurements. Furthermore, at the verge of superconductivity we find a wide range of temperature independent resistance associated with vanishing Hall resistance, demonstrating the emergence of quantum metallic-like state with the Bose-metal scenario of the metallic phase. By tuning the thickness of Ti$_2$O$_3$ films, the emergence of quantum metallic-like state accompanies with the appearance of superconductivity as decreasing in temperature, implying that the two-dimensional superconductivity is evolved from the quantum metallic-like state driven by the cooperative effects of the electron correlation and the interfacial coupling between Ti$_2$O$_3$ and polar GaN. These findings provide a new platform for the study of intriguing two-dimensional superconductivity with a delicate interplay of the electron correlation and the interfacial coupling at the heterostructures, and unveil the clues of the mechanism of unconventional superconductivity.Comment: 17 pages, 4 figure

Quantum metallic state in the titanium sesquioxide heterointerface superconductor

The emergence of the quantum metallic state marked by a saturating finite electrical resistance in the zero-temperature limit in a variety of two-dimensional superconductors injects a new momentum to the realm of unconventional superconductivity. Despite much research efforts over last few decades, there is not yet a general consensus on the nature of this unexpected quantum metal. Here, we report the unique quantum metallic state within the hallmark of Bose-metal characterized by the saturated resistance and simultaneously vanished Hall resistance in the titanium sesquioxide heterointerface superconductor Ti$_2$O$_3$/GaN. Strikingly, the quantum bosonic metallic state proximate to the two-dimensional superconductivity-metal transition tuned by magnetic fields persists in the normal phase, suggesting that the existence of composite bosons formed by electron Cooper pairs survives even in the normal phase. Our work marks the observation of the preformed electron Cooper pairs in heterointerface superconductor and sheds new light on understanding the underlying pairing mechanism of unconventional superconductivity.Comment: 6 pages, 4 figure