New Prenylated Flavones from the Roots of Ficus Beecheyana

Two new prenylated flavanones, ficubee A and ficubee B, respectively, as 7,8‐(2,2‐dimethylpyrano)‐6‐prenyl‐5,3′,4′‐trihydroxyflavone and 6,7‐(2,2‐dimethylpyrano)‐8‐prenyl‐5,3′,4′‐trihydroxyflavone were isolated from the roots of Ficus beecheyana together with twelve known compounds: β‐sitosterol, 5‐stigmasten‐3β,7α‐diol, 5‐stigmasten‐3β,7β‐diol, 3β‐hydroxystigmast‐5‐en‐7‐one, 4‐hydroxybenzaldehyde, 4‐hydroxy‐3‐methoxybenzaldehyde, 1‐(4‐hydroxyphenyl)‐ethanone, 4‐hydroxy‐3‐methoxybenzoic acid, 4‐hydroxy‐cinnamic acid, seseline, xanthyletin, and psoralene. The structures of these secondary metabolites were determined by spectroscopic means and in comparison with published data.     

The effect of the polyaniline morphology on the performance of polyaniline supercapacitors

The polyaniline (PANI) prepared by the pulse galvanostatic method (PGM) or the galvanostatic method on a stainless steel substrate from an aqueous solution of 0.5 mol/l H₂SO₄ with 0.2 mol/l aniline has been studied as an electroactive material in supercapacitors. The electrochemical performance of the PANI supercapacitor is characterized by cyclic voltammetry, a galvanostatic charge–discharge test and electrochemical impedance spectroscopy in NaClO₄ and HClO₄ mixed electrolyte. The results show that PANI films with different morphology and hence different capacitance are synthesized by controlling the synthesis methods and conditions. Owing to the double-layer capacitance and pseudocapacitance increase with increasing real surface area of PANI, the capacitive performances of PANI were enhanced with increasing real surface area of PANI. The highest capacitance is obtained for the PANI film with nanofibrous morphology. From charge–discharge studies of a nanofibrous PANI capacitor, a specific capacitance of 609 F/g and a specific energy density of 26.8 Wh/kg have been obtained at a discharge current density of 1.5 mA/cm². The PANI capacitor also shows little degradation of capacitance after 1,000 cycles. The effects of discharge current density and deposited charge of PANI on capacitance are investigated. The results indicate that the nanofibrous PANI prepared by the PGM is promising for supercapacitors.     

Bag model approach to the intermediate states in hadronic transitions in heavyQ\bar Q systems

Instead of the quark confining string model (QCS) used in [4], a bag model approach to the intermediate states in hadronic transitions in heavy \(Q\bar Q\) systems is studied. The calculation is based on a spherical bag model with Born-Oppenheimer approximation. It is shown that the spectra of intermediate states in this approach are quite different from those obtained in the QCS model, while normalized by the experimental data of Γ(ψ′→ψππ) the two approaches give very similar results for most of the hadronic transition rates in the \(b\bar b\) system. This shows that the results in [4] are not sensitive to the models of the intermediate states. The present approach can also be applied to the study of intermediate states including light quarks.     

面向CO2电化学转化的铜基催化剂研究进展

Burning of fossil fuels increases CO₂ concentration in the atmosphere, resulting in a series of climate- and environment-related concerns such as global warming, sea-level rise, and melting of glaciers. Therefore, utilization of renewable energy to reduce the CO₂ concentration, in order to realize a sustainable development, is urgent. Capturing and utilizing CO₂, a greenhouse gas, can not only address these concerns but also alleviate the current scenario of energy shortage. Thermal catalytic CO₂ hydrogenation offers various pathways with high conversion efficiencies to produce fuels and industrial chemicals including CO, HCOOH, CH₃OH, and CH₄. However, CO₂ is chemically inert due to the highly stable C＝O bond. Thus, harsh reaction conditions such as high temperature and pressure are required for CO₂ hydrogenation.     

CdS/SiO2纳米棒核/壳结构的制备和发光性能

利用在醇介质中氨水催化水解硅酸乙酯（TEOS）制备SiO2来包覆半导体CdS纳米棒而形成CdS/SiO2核/壳结构.通过X射线衍射（XRD）、透射电子显微镜（TEM）证实SiO2包覆壳层为非晶，且壳层厚度随TEOS浓度的增大而增加，在10～30 nm之间.并研究了其紫外 可见吸收光谱（UV Vis）和荧光发射光谱(PL)的性质.     

Neutral red as electron transfer mediator: enhanced electrocatalytic activity of platinum catalyst for methanol electro-oxidation

Organic molecule neutral red (NR), as electron transfer mediator, was introduced in the anodic electrocatalyst system for methanol oxidation and the resulting electrode was investigated by cyclic voltammetry, polarization method, and electrochemical impedance spectroscopy. For the same loading mass of platinum catalyst, 1.25 times larger exchange current density, 1.83 times higher specific activity, and better long-term cycle stability can be obtained at Pt/NR/graphite electrode, as compared to the electrode without NR. These results indicate that neutral red plays an important role on the enhanced electrocatalytic activity of platinum catalyst for methanol oxidation.     

First report of a nano‐Cu2O‐catalyzed protocol for homo‐coupling reaction of terminal alkynes in water/ionic liquid medium

A new, efficient and green protocol for the nano‐Cu₂O‐catalyzed homo‐coupling reaction of terminal alkynes has been developed, using water/ionic liquid as an environmentally friendly solvent. Moreover, the system also allows the synthesis of unsymmetric 1,3‐diynes by cross‐coupling of two different terminal alkynes. It is noteworthy that the nano‐Cu₂O‐catalyzed methodology is a good supplement to copper catalyst for the Glaser‐type homo‐coupling reaction. Copyright © 2016 John Wiley & Sons, Ltd.     

New 3 D Tubular Porous Structure of an Organic–Zincophosphite Framework with Interesting Gas Adsorption and Luminescence Properties

A new 3D tubular zinc phosphite, Zn₂(C₂₂H₂₂N₈)_0.5(HPO₃)₂?H₂O ( 1 ), incorporating a tetradentate organic ligand was synthesized under hydro(solvo)thermal conditions and structurally characterized by single‐crystal X‐ray diffraction. Compound 1 is the first example of inorganic zincophosphite chains being interlinked through 1,2,4,5‐tetrakis(imidazol‐1‐ylmethyl)benzene to form a tubular porous framework with unusual organic–inorganic hybrid channels. The thermal and chemical stabilities, high capacity for CO₂ adsorption compared to that for N₂ adsorption, and interesting optical properties of LED devices fabricated using this compound were also studied.