Microporous La–Metal–Organic Framework (MOF) with Large Surface Area

A microporous La–metal‐organic framework (MOF) has been synthesized by the reaction of La(NO₃)₃ ? 6 H₂O with a ligand 4,4′,4′′‐s‐triazine‐1,3,5‐triyltri‐p‐aminobenzoate (TATAB) featuring three carboxylate groups. Crystal structure analysis confirms the formation of 3D MOF with hexagonal micropores, a Brunauer–Emmett—Teller (BET) surface area of 1074 m² g^?1 and high thermal and chemical stability. The CO₂ adsorption capacities are 76.8 cm³ g^?1 at 273 K and 34.6 cm³ g^?1 at 293 K, a highest measured CO₂ uptake for a Ln–MOFs.     

Synthesis and enhanced photoluminescence in novel AucoreAu-Agshell nanoparticles embedded Nd-doped antimony oxide glass hybrid nanocomposites

Au_coreAu-Ag_shell nanoparticles and Nd³⁺ ions co-doped in a novel antimony(III) oxide based dielectric (glass) matrix were synthesized for the first time, by a new very simple single-step methodology involving selective thermo-chemical reduction without employing any external reducing agent. They were characterized by the evolution of UV-vis-NIR absorption and photoluminescence spectra, XRD patterns, TEM and SAED images. XRD and SAED indicate the building of core-shell nanoparticles through the formation of (1 1 1) and (2 0 0) planes whereas TEM advocates the generation of spherical and spheroidal particles of 22-107 nm sizes with various core morphologies. Photoluminescence upconversion exhibits two major emission bands of Nd³⁺ ions at 540 (green) and 649 (deep-red) nm which undergo about 5-fold intensity enhancement by the nanoparticles. Such enhancement is attributed to the local field effect induced by plasmonic Au-Ag nanoparticles to Nd³⁺ ions. These nanocomposites are promising for many nanophotonics applications.     

Working group report: Quantum chromodynamics (QCD) and hadronic structure

We discuss potential problems in hadronic physics. Recent developments are reviewed and possible future studies in some interesting areas which are underway are highlighted.     

无限横观各向同性弹性圆柱中刚性圆盘的扭转振动

分析了无限横观各向同性弹性圆柱中，刚性圆盘的扭转振动问题．绘制的图形显示了材料的各向异性性质对应力强度因子的影响．     

An efficient and convenient protocol for the synthesis of quinoxalines and dihydropyrazines via cyclization-oxidation processes using HClO4·SiO2 as a heterogeneous recyclable catalyst

A convenient and straightforward method has been developed for the synthesis of quinoxalines and dihydropyrazines (DHPs) using α-bromo ketones and 1,2-diamines in the presence of silica supported perchloric acid (HClO₄·SiO₂) at room temperature. The quinoxalines and DHPs were presumably formed via cyclization-oxidation. The catalyst works under heterogeneous conditions and can be recycled.     

Synthesis and Structure of Unprecedented Samarium Complex with Bulky Bis‐iminopyrrolyl Ligand via Intramolecular C=N Bond Activation

An unprecedentate samarium complex of the molecular composition [{κ³‐{(Ph₂CH)N=CH}₂C₄H₂N)}{κ³‐{(Ph₂CHN=CH)(Ph₂CHNCH)C₄H₂N}Sm}₂] ( 2 ), which was isolated by the reaction of a potassium salt of 2,5‐bis{N‐(diphenylmethyl)‐iminomethyl}pyrrolyl ligand [K(THF)₂{(Ph₂CH)N=CH}₂C₄H₂N)] ( 1 ) with anhydrous samarium diiodide in THF at 60 °C through the in situ reduction of imine bond is presented. The homoleptic samarium complex [[κ³‐{(Ph₂CH)–N=CH}₂C₄H₂N)]₃Sm] ( 3 ) can also be obtained from the reaction of compound 1 with anhydrous samarium triiodide (SmI₃) in THF at 60 °C. The molecular structures of complexes 2 and 3 were established by single‐crystal X‐ray diffraction analysis. The molecular structure of complex 2 reveals the formation of a C–C bond in the 2,5‐bis{N‐(diphenylmethyl)iminomethyl}pyrrole ligand moiety (Ph₂Py^–). However, complex 3 is a homoleptic samarium complex of three bis‐iminopyrrolyl ligands. In complex 2 , the samarium ion adopts an octahedral arrangement, whereas in complex 3 , a distorted three face‐centered trigonal prismatic mode of nine coordination is observed around the metal ion.     

Carbene‐Catalyzed Enantioselective Aldol Reaction: Post‐Aldol Stereochemistry Control and Formation of Quaternary Stereogenic Centers

The dominated approaches for asymmetric aldol reactions have primarily focused on the aldol carbon–carbon bond‐forming events. Here we postulate and develop a new catalytic strategy that seeks to modulate the reaction thermodynamics and control the product enantioselectivities via post‐aldol processes. Specifically, an NHC catalyst is used to activate a masked enolate substrate (vinyl carbonate) to promote the aldol reaction in a non‐enantioselective manner. This reversible aldol event is subsequently followed by an enantioselective acylative kinetic resolution that is mediated by the same (chiral) NHC catalyst without introducing any additional substance. This post‐aldol process takes care of the enantioselectivity issues and drives the otherwise reversible aldol reaction toward a complete conversion. The acylated aldol products bearing quaternary/tetrasubstituted carbon stereogenic centers are formed in good yields and high optical purities.     

Possibility of Love wave propagation in a porous layer under the effect of linearly varying directional rigidities

The present paper investigates the Love wave propagation in an anisotropic porous layer under the effect of rigid boundary. Effect of initial stresses on the propagation of Love waves in a fluid saturated, anisotropic, porous layer having linear variation in directional rigidities lying in contact over a pre-stressed, inhomogeneous elastic half-space has also been considered. The dispersion equation of phase velocity has been derived and the influence of medium characteristic such as porosity, rigid boundary, initial stress, anisotropy and inhomogeneity over it has been discussed. The velocities of Love waves have been calculated numerically as a function of KH (where K is the wave number and H is the thickness of the layer) and are presented in a number of graphs.