Immobilization of enzymes by radiation-induced polymerization of glass-forming monomers: 2. Effects of cooling rate and solvent on porosity and activity of immobilized enzymes

The effect of cooling rate of a monomeric system on the porosity and activity of an immobilized enzyme prepared by radiation-induced polymerization of 2-hydroxyethyl methacrylate at low temperatures has been studied. Slow cooling gave the same effect on porosity of the polymer as decreasing the monomer concentration. A glass-forming solvent such as diethylene glycol was added to water to study the effect of the supercooling tendency of the solvent. Addition of diethylene glycol decreased porosity and also enzymic activity. Water was replaced by the miscible solvent p-dioxane and the immiscible solvent n-decane in order to clarify the effect of solvent. p-Dioxane had a similar effect to water on the relation between the monomer concentration, porosity and activity. On the other hand, polymer prepared from the system containing n-decane showed different immobilization properties owing to the presence of independent pores in the matrix.     

A kinetic study on the reaction of dicumyl peroxide with some low-olefin rubbers

The viscosity lowering of toluene solutions of isobutylene-isoprene rubber, polyisobutylene, and ethylene-propylene rubber in the reaction with dicumyl peroxide was investigated. By using the kinetic equations for the reaction of rubber with peroxide which had been derived previously by KIRIYAMA et al. the results of the experiments are discussed.     

Development of ultra high strength steels based on spinodal decomposition

A new idea for the development of ultra high strength steels by utilizing the spinodal decomposition of the Fe-Mo binary system is proposed. The idea comprises the restraint of the brittleness of the Fe-Mo alloy by reducing the Mo-content necessary to spinodal decomposition and by microstructure refining such as grain refining, subgrain refining etc; the former is realized by the alloying with some elements which, in general, have a tendency towards ordering (i.e., negative interchange energy between the nearest neighbour atoms) when combined with iron, and the latter by thermomechanical treatment and/or cold rolling. On the basis of the idea, that hidden properties indispensable to high strength materials are successfully drawn from the Fe-Mo alloy; we have obtained a 4GPa grade high tensile steel of Fe-Mo-Co-V. This idea is sure to contribute new suggestions to the development of high strength materials.     

辐射聚合覆盖离子型高分子的纸固定化绿色木霉细胞

通过辐射聚合,在纸表面覆盖阳离子——疏水性共聚物polo(DEAEMA-ATMPT)和阴离子——疏水性共聚物poly(AA-ATMPT)作为固定化绿色木霉细胞的载体。试验结果表明:用覆盖poly(DEAEMA-ATMPT)的载体固定化细胞比较牢固,未因振荡而解吸;固定化细胞的FPA(滤纸活性)均高于未固定化的游离细胞,其中用覆盖25％:75％ poly(DEAEMA-ATMPT)的载体固定化细胞的FPA比游离细胞增加了20％;固定化细胞的重量随共聚物中阳离子组分的增加而增加。用覆盖poly(AA-ATMPT)的载体固定化绿色木霉也有较好的效果。但固定化细胞的重量明显低于覆盖poly(DEAEMA-ATMPT)的载体固定化细胞的重量,且它随共聚物中阴离子组分的增加而下降。阳离子——疏水性共聚物能提高固定化绿色水霉的效果;用离子型共聚材料固定化细胞静电引力起了主要的作用。     

Microstructure of carbonaceous mesophase spherule

Carbonaceous spherules of mesophase were examined by transmission electron microscopy (TEM) and X-ray diffraction to precisely clarify its structure. A series of thin sections were cut from a single spherule with a microtome, and the three-dimensional lamellar structure of the spherule investigated. From 002 dark-field images and selected area electron diffractions (SAD), it was observed that the spherule was of the Brooks-Taylor type, with the lamellae being parallel even at the poles of the spherule. Structural changes within the spherule was studied following carbonization and graphitization. The structure of the resultant coke was essentially that of spherule of mesophase. Size of the lamellae increased as well as. The number of stacking lamellae also increased, but a rapid increase was not seen. The spherules of mesophase show a high degree of homogeneity and an excellent degree of graphitization.     

日本建筑材料市场的动向

日本建筑材料协会 日本建筑材料协会是通过国土交通省、经济产业省认可的具有全国性规模的公益法人．主要以建筑材料生产厂家、销售公司、施工公司等与建材相关的企业为主体．在日本国内会员数已超过300家公司。协会于1934年成立．约有70年的历史。现在，正致力于新时代建材的开发、启蒙与普及以及会员企业和建筑业的进步、发展贡献着力量．同时还积极参与公益活动。     

Effects of grain boundary on dielectric properties in fine-grained BaTiO3 ceramics

BaTiO₃ dielectric ceramics, which have no core–shell structure, were prepared. High-resolution transmission electron microscope (TEM) and the newly developed chemical etching analysis revealed the composition of the grain boundary. The grain boundary has an important role in stabilizing temperature dependence of a dielectric constant. The grain boundary causes a large stress against grains, resulting in a change of the domain structure. So, the stress from the grain boundary is considered to depress the dielectric abnormality at the Curie temperature.     

Repetition bend properties of Cu-Cr and Cu-Cr-Sn alloys

Repetition numbers of bending of Cu-0.81 wt% Cr, Cu-0.81 wt% Cr-0.14 wt% Sn and Cu-0.26 wt% Cr-0.10 wt% Sn alloys were investigated. After solution treatment, the first two types of copper alloys have a primary chromium phase; this is not so in the last alloy. The primary chromium phase does not influence the repetition numbers of bending of cold-rolled specimens; the repetition numbers of bending of specimens aged at 723 K for 1.8 × 10³ sec after cold rolling are higher than those of cold-rolled specimens. The cause of this is considered to be a recovery of work-hardening during ageing.