不饱和脂肪酸标准物质研制之商榷

探讨了不饱和脂肪酸标准物质的制备,分析定值。     

一种新二肟的合成及其电化学行为

修饰电极;一种新二肟的合成及其电化学行为     

Solventless Formation of G‐Quartet Complexes Based on Alkali and Alkaline Earth Salts on Au(111)

Template cations have been extensively employed in the formation, stabilization and regulation of structural polymorphism of G‐quadruplex structures in vitro. However, the direct addition of salts onto solid surfaces, especially under ultra‐high‐vacuum (UHV) conditions, to explore the feasibility and universality of the formation of G‐quartet complexes in a solventless environment has not been reported. By combining UHV‐STM imaging and DFT calculations, we have shown that three different G‐quartet‐M (M: Na/K/Ca) complexes can be obtained on Au(111) using alkali and alkaline earth salts as reactants. We have also identified the driving forces (intra‐quartet hydrogen bonding and electrostatic ionic bonding) for the formation of these complexes and quantified the interactions involved. Our results demonstrate a novel route to fabricate G‐quartet‐related complexes on solid surfaces, providing an alternative feasible way to bring metal elements to surfaces for constructing metal–organic systems.     

Compounds with inhibitory activity on peristalsis from the seeds of Holarrhena antidysenterica

Eight compounds were isolated from the seeds of Holarrhena antidysenterica Wall.ex A.DC. On the basis of physico-chemical properties and spectroscopic data, holarrhenanan (1) was identified as a new compound, compounds 2–3 were isolated from H. antidysenterica for the first time, and five known compounds were also obtained. Inhibitory effects of some compounds and extracts to the intestinal peristalsis were evaluated. Results showed that the extracts and compounds 4, 6 exhibited remarkable inhibitory effects with tension inhibition rate of 32.77, 32.77% and amplitude inhibition rate of 59.51, 55.98%, respectively on the vitro rabbit intestinal peristalsis.     

Salt spray corrosion behavior and pitting resistance of Ti-15 V-3Cr-3Al-3Sn alloy evaluated using XPS,SKPFM, and electrochemical technique

Journal of Solid State Electrochemistry - As a promising material for many industrial applications, Ti-15 V-3Cr-3Al-3Sn (commonly referred to as Ti-15–3) titanium alloy always...     

Chronology and origin of VMS deposits in Xinjiang,NW China

VMS deposits in Xinjiang, NW China are widespread in the Altay, Tianshan and West Kunlun orogenic belt, mainly formed during the Proterozoic rifting and Phanerozoic post-orogenic extension and are related to the bimodal volcanism. The VMS deposits are middle and small in scale. According to assemblages of metallogenetic elements, they can be divided into four types (Cu-Zn, Cu-S, Pb-Zn-Cu and Pb-Zn types) with the Cu-Zn and Pb-Zn types being the most important ones. Research of isotopic chronology shows that the VMS deposits in Xinjiang were formed during the Proterozoic, Ordovician, Deovonian, Carboniferous and Permian periods and usually underwent multi-stage mineralization, especially the large-sized deposits usually have post-volcanic superimposed mineralization by tectonomagmatic or metamorphic hydrothermal metal-logenic fluids.     

Lu-Eu共掺杂Ga2O3的光电性质的第一性原理计算

宽禁带半导体β-Ga₂O₃因为具有优良的物理化学性能而成为研究热点.本文基于DFT(Density Functional Theory)的第一性原理方法,先采用PBE(Perdew-Burke-Ernzerhof)中的GGA(Generalized Gradient Approximation)和GGA+U(Generalized Gradient Approximation-Hubbard U)的方法计算了本征β-Ga₂O₃,Lu掺杂浓度为12.5%的β-Ga₂O₃及Lu-Eu共掺杂浓度为25%的β-Ga₂O₃结构的晶格常数、能带结构和体系总能量.发现采用GGA+U的方法计算的带隙值更接近实验值,于是采用GGA+U的方法计算了本征β-Ga₂O₃,Lu掺杂的β-Ga₂O₃以及Lu-Eu共掺杂的β-Ga₂O...     

Narrowband blue emission with insensitivity to the doping concentration from an oxygen-bridged triarylboron-based TADF emitter: nondoped OLEDs with a high external quantum efficiency up to 21.4%

Blue thermally activated delayed fluorescence (TADF) emitters that can simultaneously achieve narrowband emission and high efficiency in nondoped organic light-emitting diodes (OLEDs) remain a big challenge. Herein, we successfully design and synthesize two blue TADF emitters by directly incorporating carbazole fragments into an oxygen-bridged triarylboron acceptor. Depending on the linking mode, the two emitters show significantly different photophysical properties. Benefitting from the bulky steric hindrance between the acceptor and terminal pendants, the blue emitter TDBA-Cz exhibited a high photoluminescence quantum yield (PLQY) of 88% in neat films and narrowband emission. The corresponding non-doped blue device exhibited a maximum external quantum efficiency (EQE) of 21.4%, with a full width at half maximum (FWHM) of only 45 nm. This compound is the first blue TADF emitter that can concurrently achieve narrow bandwidth and high electroluminescence (EL) efficiency in nondoped blue TADF-OLEDs.

A donor–acceptor TADF emitter showed narrowband high-efficiency blue emission by fine molecular modulation. The corresponding OLEDs exhibited a maximum EQE of 21.4% and a small FWHM of 45 nm, representing the most efficient nondoped blue TADF-OLEDs.     

One-pot synthesis of uniform hollow cuprous oxide spheres fabricated by single-crystalline particles via a simple solvothermal route

Uniform Cu₂O hollow spheres fabricated by single-crystalline particles (smaller than 20 nm) are facile synthesized in ethylene glycol (EG) solution by a simple solvothermal route without using pre-fabricated templates and reductive agents. EG in this protocol is not only used as a solvent, complexing agent, and reducing agent, but also served as a structure-directing agent for the formation of hollow structure. By control of reaction conditions, such as reaction time, temperature, and the anions, the morphology and structure of the hollow spheres can be tuned. A coordination adsorption and oriented attachment and Ostwald ripening mechanism is proposed for explaining the formation process of hollow Cu₂O spheres in EG solution; and importantly, the hollow Cu₂O spheres exhibit an excellent property for the electro-catalytic oxidization of ascorbic acid in acetic acid buffer solution. Moreover, the hollow spherical Cu₂O particles could be potentially applied in catalysis, sensor, and as model for fundamental research.