Rhodium-catalyzed C-H activation has emerged as a powerful and promising tool for constructing diverse heterocyclic systems in organic synthesis.1]Recently years have increased interest in the annulation of hydrazines...
Rhodium-catalyzed C-H activation has emerged as a powerful and promising tool for constructing diverse heterocyclic systems in organic synthesis.1]Recently years have increased interest in the annulation of hydrazines,which has prepared the indoles,2,3-dihydro-1H-indazoles and pyrazoles.
As potential thermal barrier coating （TBC） materials, Ruddlesden-Popper structured BaLn2Ti3010 （Ln = rare earth） compounds possess excellent phase stability and desirable thermo-physical properties as well as inte...
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As potential thermal barrier coating （TBC） materials, Ruddlesden-Popper structured BaLn2Ti3010 （Ln = rare earth） compounds possess excellent phase stability and desirable thermo-physical properties as well as interesting anisotropic structure. In this paper, the effects of pressure during BaLa2Ti3010 （BLT） bulk preparation on the grain orientation were investigated. BLT grains exhibited lamellar structure, but the grain orientation depended strongly on the existence of pressure during bulk preparation. When pressure was applied, BLT grains preferentially grew along pressing direction, leading to formation of the texture parallel to pressing direction, but BLT grain orientation became relatively random when pressure was absent. However, in the small scale area, BLT grains grew preferentially along c-axis with independence on pressure during preparation. Pressure affected BLT grain orientation at the rapid growth stage according to the grain growth model of BLT.
A novel glucose biosensor based on graphene nanosheets(GNs)modified gold nanowire arrays(AuNWAs)electrode was *** ordered gold nanowire arrays were prepared by direct electrodeposition in anodic aluminum oxide *** wer...
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A novel glucose biosensor based on graphene nanosheets(GNs)modified gold nanowire arrays(AuNWAs)electrode was *** ordered gold nanowire arrays were prepared by direct electrodeposition in anodic aluminum oxide *** were synthesized through a public route involving graphite oxidation,exfoliation,and chemical *** emission scanning electron microscope and high-resolution transmission electron microscope were employed to characterize the asprepared AuNWAs and *** oxidase was immobilized on the surface of GNs-AuNWAs modified electrode via a cross-linking *** cyclic voltammetry results showed that the GNs-AuNWAs-based glucose biosensors have high catalysis activity to hydrogen peroxide(H2O2)than those modified with GNs or AuNWAs ***,amperometric response was employed to detect glucose concentration owing to its simplicity,high selectivity,and relative low *** biosensors based on GNs-AuNWAs showed excellent performance with high sensitivity of 40.25 lA cm-2(mmol/L)-1,low detection limit of 0.02 mmol/L,and a linear range from 0.02 to 3 mmol/L.
The negative thermal expansion （NTE） properties of the antiperovskite manganese nitrides with micron-scale, submicron-scale and nanometer-scale microstructures, respectively, were investigated using the Mn3Cu0.5Ge0....
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The negative thermal expansion （NTE） properties of the antiperovskite manganese nitrides with micron-scale, submicron-scale and nanometer-scale microstructures, respectively, were investigated using the Mn3Cu0.5Ge0.5N composition as an example. It was discovered that the NTE start temperature, NTE operation temperature range and coefficient of NTE change obviously in a wide range with decreasing the grain size level of the microstructure. The mechanisms for the broadening of the NTE operation temperature range and the decrease in the absolute value of NTE coefficient were proposed based on the grain-size-dependence of the frustrated magnetic interactions and magnetic ordering. The present study indicates that the NTE properties of the antiperovskite manganese nitrides can be tailored by the control of the microstructure scale.
The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for develo...
The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lap shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.
Two polyborosiloxanes （PBSis） with char yield up to 74.13% at 800 ℃ were synthesized by the direct polycondensation of boric acid with phenyltrimethoxysilane in diglyme. The PBSis were characterized by gel permeati...
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Two polyborosiloxanes （PBSis） with char yield up to 74.13% at 800 ℃ were synthesized by the direct polycondensation of boric acid with phenyltrimethoxysilane in diglyme. The PBSis were characterized by gel permeation chromatography, IR spectroscopy as well as ^1H-, ^29Si- and ^11B-NMR. PBSi modified phenol-formaldehyde resins （PBSi/PFs） were prepared at different PBSi/PF mass ratios and were cured at 150 ℃. The PBSi/PFs were characterized by IR spectroscopy, scanning electron microscopy, thermogravimetric analysis and tensile test. The results revealed that the cured PBSi/PFs had sea-island morphology and higher char yield than the common PF. PBSi/PF blend with PBSi/PF mass ratio of 0.4：1 had char yield up to 70.83% at 800 ℃. The PBSi/PFs had tensile strength similar to PF. The ceramization of PBSi/PFs was also studied. The silicon boron oxycarbide （SiBOC） ceramics formed were characterized by IR spectroscopy and elemental analysis. This method provided a valuable way to prepare easily shapeable polymer blends as ceramic precursors.
A facile and environment friendly approach to synthesis of unique hierarchical BiOCl flowery microspheres(FMs)using a biodegradable surfactant polyvinyl alcohol(PVA)was reported herein for the first *** to the BiOCl n...
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A facile and environment friendly approach to synthesis of unique hierarchical BiOCl flowery microspheres(FMs)using a biodegradable surfactant polyvinyl alcohol(PVA)was reported herein for the first *** to the BiOCl nanosheets synthesized in the absence of PVA,hierarchical BiOCl FMs consist of large amounts of interwoven polycrystalline nanosheets that assemble into a porous flowery *** formation mechanism of the hierarchical BiOCl FMs was also proposed,whereby PVA was believed to play a key role in the crystal growth and the formation of the final *** with TiO2-P25 and BiOCl nanosheets,hierarchical BiOCl FMs displayed remarkably enhanced photocatalytic activity,and20 mg of BiOCl FMs could completely degrade 50 mL of methyl orange solution(20 mg/L)within 30 min under UVlight *** to the comprehensive analysis,it can be concluded that the larger specific surface area,porosity,suitable band gap,and the enhanced light absorption capacity may contribute to the remarkably enhanced photocatalytic *** facile and green approach to fabricating hierarchical BiOCl FMs would give vital clues to develop new route for synthesizing other hierarchical structured materials.
The electronic structure, nonlinear electronic polarization induced by a static external electric field, and frequency dependent second-harmonic susceptibility tensor of the borophosphate BPO4 are studied by a first-p...
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The electronic structure, nonlinear electronic polarization induced by a static external electric field, and frequency dependent second-harmonic susceptibility tensor of the borophosphate BPO4 are studied by a first-principles calculation based on density-functional theory. Our calculated results show that the borophosphate BPO4 has a large band gap ∼10.4 eV, which is larger than the band gap of the widely used nonlinear optical crystal KBe2BO3F2. However, BPO4 also has a nonlinear coefficient d36=0.92 pm/V at static limit, which also is larger than the nonlinear coefficient d11=0.47 pm/V of KBe2BO3F2. The unexpected larger nonlinear coefficient of BPO4 can be interpreted by the relatively strong s−p hybridization in BPO4, which can enhance the inter-band Berry connections, while the O 2p orbitals dominating valence bands in KBe2BO3F2 are very flat, resulting from weak s−p hybridization.
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