A novel active ester synthesis reagent (N,N′-disuccinimidyl carbonate)

A convenient reagent for active ester synthesis --N,N′-disucinimidyl carbonate-- was prepared. This reagent was useful for the preparation of active esters and peptides in stead of dicyclohexylcarbodiimide.     

Studies on Rydberg orbitals. IV. Basic formulas for the one-electron perturbation calculation of molecular Rydberg excited states

General expressions are obtained for the energies of complex and real forms of any hydrogenic orbital (n, l, m) in a cluster of point charges of any geometry. This is a perturbation calculation of hydrogenic Rydberg orbitals in a one-electron hard core approximation. A model calculation of 3d-electrons of carbene, ethylene and benzene with varying charge distribution is given.     

A New Crystal Form,Polymorphism, and Multi‐Morphology in Biodegradable Poly(3‐hydroxypropionate)

Summary: A new crystal morphology (δ form) of poly(3‐hydroxypropionate) (PHP) is found in cast and melt‐crystallized PHPs with low molecular weight, in which the PHP chains possibly adopt a 2₁ helix rather than the trans conformation found in the β or γ form. The fusion temperature‐ and the crystallization temperature‐dependent polymorphism are responsible for the dual morphologies and the unique growth kinetics of spherulites in the melt‐crystallized PHPs.

a) A dual‐morphology developed at 70 °C in PHP films after melting at 117 °C and b) that formed during cooling at a rate of 1 °C · min⁻¹ from 130 °C.     

Photomechanical Switching Behavior of Semi‐Interpenetrating Polymer Network Consisting of Azobenzene‐Carrying Crosslinked Poly(vinyl ether) and Polycarbonate

Summary: A novel semi‐interpenetrating polymer network (semi‐IPN) with photomechanical switching ability was developed by a cationic copolymerization of azobenzene‐containing vinyl ethers in a matrix of a linear polycarbonate (PC). The semi‐IPN film showed reversible deformation upon switching the UV irradiation on and off and responded with unprecedented rapidity. The photomechanical effect is attributed to a reversible change between the highly aggregated and dissociated states of the azobenzene groups.

The reversible UV response of the length of the semi‐IPN film at 25 °C.     

Na10(glycine)2[H2W12O42]·28H2O

The title compound, decasodium diglycine di­hydro­geno­do­tetra­conta­do­deca­tung­state(10?) octa­cosa­hydrate, consists of a centrosymmetric paratungstate [H₂W₁₂O₄₂]^10? anion, ten Na⁺ cations, two zwitterionic glycine molecules and 28 water molecules of crystallization. Two glycine carboxylate O atoms coordinate three different Na⁺ cations, while the amino N atom forms hydrogen bonds with the paratungstate anion through both terminal and bridging O atoms.     

A Facile Synthesis of Thioacids by Hydrolysis of 1-(Acylthio)ethaniminium Chlorides

A facile method for the preparation of thioacids in moderate to good yields has been developed by hydrolysis of 1-(acylthio)ethaniminium chlorides under a liquid-liquid two phase system consisting of benzene and a sodium hydroxide aqueous solution at room temperature. We have achieved facile preparation of these compounds without use of toxic compounds such as hydrogen sulfide.     

Flutter of hanging roofs and curved membrane roofs

This paper presents the determination method of flutter critical wind velocity of hanging roofs and curved membrane roofs of which outer surface only is exposed to wind, and some numerical results for fundamental shape of the roofs are illustrated to make clear the influences of curvatures, materials, size factors and prestressing on this critical velocity, and the dynamic behavior of the roofs subjected to wind. The procedure to formulate the governing equations is on the basis of classical flow theory with vorticities in the boundary layer and in the wake from the trailing edge, and the solution is obtained with Galerkin's procedure.