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Effects of post annealing on the physical and electrical properties of solar-blind polycrystalline gallium oxide (Ga2O3) ultraviolet photodetectors on the sapphire substrate are investigated. The grain size of poly-Ga2O3 becomes larger with the post annealing temperature (PAT) increasing from 800 °C to 1000 °C, but it gets smaller with further raising PAT to 1100 °C. A blue shift is observed at the absorption edge of the transmittance spectra of Ga2O3 on sapphire as increasing PAT, due to the incorporation of Al from the sapphire substrate into Ga2O3 to form (AlxGa1–x)2O3. The high-resolution X-ray diffraction and transmittance spectra measurement indicate that the substitutional Al composition and bandgap of (AlxGa1–x)2O3 annealed at 1100 °C can be above 0.30 and 5.10 eV, respectively. The Rmax of the sample annealed at 1000 °C increases about 500% compared to the as-deposited device, and the sample annealed at 1000 °C has short rise time and decay time of 0.148 s and 0.067 s, respectively. This work may pave a way for the fabrication of poly-Ga2O3 ultraviolet photodetector and find a method to improve responsivity and speed of response. [ABSTRACT FROM AUTHOR]

In this study, an eddy current (EC) detector is integrated in an additive/subtractive hybrid manufacturing (ASHM) process. The detector facilitates in-process inspection and repair operations through material deposition, defect detection, and removal processes layer by layer. A feasibility test is carried out on eddy current detection of subsurface defects in additively manufactured parts by using an EC detector. The study compares the results obtained from the EC detection with those by the X-ray computed tomography and the destructive methods. Experiments and simulations are conducted to investigate the effect of excitation frequency on intensity of the eddy current signal. The effects of residual heat of an additively manufactured specimen and lift-off distance of an EC probe on impedance changes are also investigated. In addition, the effect of defect width on EC signal is analyzed. The study shows that the EC method is capable of detecting subsurface defects in the ASHM parts. It is promising to integrate the EC detection and subtractive manufacturing into additive manufacturing to produce parts with improved quality and better performances. [ABSTRACT FROM AUTHOR]

As the main alkali and alkaline-earth oxides in red mud, the effects of Na 2 O and CaO on the physical properties, crystalline phases and microstructure of red mud based ultra-lightweight ceramsite (RUC) were systematically investigated using XRD, FTIR and SEM-EDS methods. Na 2 O and CaO promote the generation of glass phase and reduce the viscosity of liquid phase. A proper Na 2 O content accelerates the formation of internal large size pores and the expansion of ceramsite, but excessive Na 2 O makes the pores grow and connect to each other and then reduces the compressive strength of RUC. The presence of CaO produces the glass phase with high fluidity that can fill the internal pores of RUC, thereby reducing the expansion property and water absorption. High contents of Na 2 O and CaO accelerate the crystallization of nepheline and anorthite respectively, and the formation of anorthite is contributed to improve the strength of RUC. The bulk density and compressive strength of RUC can reach 365–485 kg/cm3 and 1.05–1.53 MPa when the contents of Na 2 O and CaO in RUC are controlled within 3% and 3.5%, respectively, which meet the requirement of GB/T 17431.2–2010. [ABSTRACT FROM AUTHOR]

Austenitic stainless steel 316L is ion implanted by carbon with implantation fluences of 1.2 × 10 17 ions-cm − 2 , 2.4 × 10 17 ions-cm − 2 , and 4.8 × 10 17 ions-cm − 2 . The ion implantation induced graded microstructure and phase transformation in stainless steel is investigated by X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. The corrosion resistance is evaluated by potentiodynamic test. It is found that the initial phase is austenite with a small amount of ferrite. After low fluence carbon ion implantation, an amorphous layer and ferrite phase enriched region underneath are formed. Nanophase particles precipitate from the amorphous layer due to energy minimization and irradiation at larger ion implantation fluence. The morphology of the precipitated nanophase particles changes from circular to dumbbell-like with increasing implantation fluence. The corrosion resistance of stainless steel is enhanced by the formation of amorphous layer and graphitic solid state carbon after carbon ion implantation. [ABSTRACT FROM AUTHOR]

In the present study, Zr 0.8 Ti 0.2 Co 1− x Fe x ( x = 0, 0.1, 0.2 and 0.3) alloys were prepared by arc melting method. The effect of Fe substitution on microstructure and hydrogen storage properties was studied systematically. The phase structure and hydrogen storage properties were characterized by X-ray diffraction (XRD), Electron Probe Micro-analysis (EMPA) and Sievert's type volumetric apparatus. XRD and EPMA analysis show that Zr 0.8 Ti 0.2 Co alloy forms cubic phase ZrCo and traces of ZrCo 2 , while the alloys of composition with x = 0.1, 0.2 and 0.3 form cubic phase ZrCo with the secondary Laves phases Zr(Co,Fe) 2 and Zr 2 Co. The cell volumes and content of the secondary phase increase gradually as the content of Fe substitution increases. The hydrogen storage experiment shows that Fe substitution for Co ameliorates initial hydriding kinetic property and shortens the incubation duration of the Zr 0.8 Ti 0.2 Co 1− x Fe x ( x = 0.1, 0.2 and 0.3) alloys, compared with Zr 0.8 Ti 0.2 Co alloy. The improved kinetic property is due to the catalyst effect of the secondary phase, which makes it favorable for the application in International Thermonuclear Experimental Reactor (ITER). [ABSTRACT FROM AUTHOR]

[Display omitted] • Four-coordinate N-heterocyclic carbene (NHC) Cu(I) complexes with nonconjugated NHC ligand are synthesized and characterized. • The photophysical properties of the corresponding complexes is studied. • Complexes show deep blue emission in 452–466 nm region. • DFT and TDDFT calculations were employed to rationalize the photophysical properties. In the present study, a series of the four-coordinate N-hetercycle carbene (NHC) copper (I) complexes [Cu(MethyIm-Meth-benzTriazole)(POP)]PF 6 (P1), [Cu(BenzyIm-Meth-benzTriazole)(POP)]PF 6 (P2), and [Cu(BenzyBenzoIm-Meth-benzTriazole)(Xantphos)]PF 6 (P3), MethyIm-Meth-benzTriazole = 1-((1-benzyl-1 H -1,2,3-triazol-4-yl)methyl)-3-methyl-1 H -imidazolylidene, BenzyIm-Meth-benzTriazole = 1-((1-benzyl-1 H- 1,2,3-triazol-4-yl)methyl)-3-phenyl-1 H -imidazolylidene, BenzyBenIm-Meth-benzTriazole = 3-benzyl-1-((1-benzyl-1 H -1,2,3-triazol-4-yl)methyl)-1 H -benzo[d]imidazolylidene, POP = bis[(2-diphenylphosphino)phenyl]ether, have been synthesized and characterized. The molecular structure of P2 has been established by single-crystal X-ray diffraction study. The addition of the methylene spacer into the NHC ligand effectively breaks the π-conjugation of the ligand, resulting in a larger HOMO-LUMO energy gap. In the solid state, P1 – P3 exhibit deep blue emission in the range of 452–466 nm with the excited-state lifetimes (τ) of 14.9–16.2 μs and the emission quantum yields (Φ) of 8.50–11.9 % at room temperature. Additionally, the photophysical properties are explained by using density functional theory (DFT) and time dependent DFT. [ABSTRACT FROM AUTHOR]

In the present study, a series of the four-coordinate N-hetercycle carbene (NHC) copper (I) complexes [Cu(Ph-Im-cyPy)(Xantphos)]PF 6 (P1), [Cu(DimBenPh-Im-cyPy)(Xantphos)]PF 6 (P2), and [Cu(BenDimBenIm-CNPy)(Xantphos)]PF 6 (P3), Ph-Im-cyPy=3-benzyl-1-(4-cyano-pyridin-2-yl)-1 H -imidazolylidene, DimBenPh-Im-cyPy=3-(3,5-dimethylbenzyl-1-(4-cyano-pyridin-2-yl)-1 H -imidazolylidene, BenDimBenIm-CNPy=3-benzyl-1-(4-cyano-pyridin-2-yl)-1 H -5,6-dimethylbenzimidazolylidene, Xantphos=9,9-dimethyl-4,5-bis(diphenylphosphino)-9 H -xanthene, have been synthesized and characterized. The molecular structures of P1 – P3 have been established by single-crystal X-ray diffraction study. In the solid state, P1 – P3 exhibit orange-red emission in the range of 621–643 nm with shorter excited-state lifetimes (τ) of 5.73–6.42 μs and the emission quantum yields (Φ) of 1.0–3.9 % at room temperature. Additionally, the photophysical properties are explained by using density functional theory (DFT) and time dependent DFT. [Display omitted] [ABSTRACT FROM AUTHOR]

This article demonstrates the fabrication of 3D hierarchical porous graphene aerogels (HGAs) with tunable porous architecture by a “fishing” process with polystyrene (PS) particles as sacrificial templates. Structure and morphology were characterized by X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM), respectively. The 3D HGAs exhibits low density, super hydrophobicity, high porosity and good thermal stability, which were used as adsorbents for removal of oils and organic solvents, showing highly efficient adsorption. In addition, they could be regenerated by heat treatment to release the adsorbates. After eight toluene-adsorbing and drying recycles, the adsorption capacity of HGAs reaches 93% of the initial uptake. [ABSTRACT FROM AUTHOR]

• The article we are going to contribute has the following highlights: • Two rare earth metal organic frameworks were synthesized by solvothermal method using zwitterionic 1,3-Bis(1-carboxylatoethyl)imidazolium bromide as ligand. • Complex 2 of Gd(C 9 H 11 N 2 O 4)(C 2 O 4)(H 2 O) (C 9 H 11 N 2 O 4 2‒ = 1,3-Bis(1-carboxylatoethyl) imidazolium ion, C 2 O 4 2- = oxalate) shows antiferromagnetic interactions in the temperature range 2−300 K. Good water-solubility, integrity and stability of 2 significantly different from common complexes grant it great potential in bio-related applications. Two rare earth coordination polymers named {[La 6 (C 9 H 11 N 2 O 4) 11 (H 2 O) 2 (OH) 2 ]⋅Br 5 } n (1) and [Gd(C 9 H 11 N 2 O 4)(C 2 O 4)(H 2 O)] n (2) (C 9 H 11 N 2 O 4 2‒ = 1,3-bis(1-carboxylatoethyl) imidazolium ion, C 2 O 4 2- = oxalate) were solvothermally synthesized using zwitterionic 1,3-bis(1-carboxylatoethyl)imidazolium bromide as ligand. 1 and 2 were both structurally characterized by single crystal X-ray diffraction, and their thermodynamic properties and magnetic properties of 2 were studied. In the 3D structure of 1 , La3+ ions are all ten-coordinated and exhibit three different coordination environments. This 3D structure of 1 is formed by La−O coordination bonds with Br− located in the cavities through H-bond and electrostatic attraction. Different from 1 , all Gd3+ ions in 2 have the same eight-coordinated environment. These two coordination polymers both have good thermostability until 323 °C for 1 and 375 °C for 2 , and then decompose giving rise to La 2 O 3 and Gd 2 O 3 , respectively. The magnetic behaviors of 2 are measured in the temperature range 2–300 K. [Display omitted] [ABSTRACT FROM AUTHOR]