Advanced Materials Research Vols. 391-392

Abstract: A new glycocerebroside (1), along with one additional known glycocerebroside (2), was isolated from the chloroform-soluble lipid fraction of the ethanol extract of Sagina japonica (Caryophyllaceae) and characterized. The structure and relative stereochemistry of two compounds were identified as (2S, 3R, 4E, 8E, 10E)-1-(β-D-glucopyranosyl)-3-hydroxy-2-[(R)-2′-hydroxy palmitoyl] amino-4, 8, 10-octadeca-tri-ene (1) and (2S, 3R, 4E, 8E)-1-(β-D-glucopyranosyl)-3-hydroxy -2-(palmitoyl)amino-4, 8-octadeca-di-ene (2) by means of spectroscopic (¹H, ¹³C, and 2D NMR; MS).

Abstract: Quartz grains were extracted from volcano ash beside Huguang Maar Lake, and the thermoluminescence (TL) of the grains was measured. Based on the thermoluminescence data of quartz the paleodose of volcanic ash beside Huguang Maar Lake was calculated with sensitized revise technique. The calculated TL dose depending on TL about 315^◦C is 75.3±4.8Gy, while the calculated dose depending on TL about 407^◦C is 115±8Gy. A physical model is set up to analyze the difference of the two calculation doses, and it can be seen that the latter is relatively veracious.

Abstract: In this paper, in situ observation of fracture process of short carbon fibers/epoxy (SCF/EP) composites was researched. The samples were prepared firstly. And then, in order to get high quality reconstruction images of carbon fiber–epoxy composites, experiments of in situ static observation of SCF/EP composites were carried out. As results, static 2D and 3D reconstruction images of fiber-epoxy composites were obtained. At last, a special small tensile testing device which can be used to apply extraneous force to small samples was designed. Based on the above work, in situ observation of fracture process of composites will be realized most probably in the next work.

Abstract: The reductive degradation of 2,4-dinitrotoluene (2,4-DNT) by three kinds of iron-based materials, namely, copper-doped iron, scrap iron and iron powder, was investigated in detail. The effects of iron materials, pH and iron dosage on the removal efficiency were studied. The results indicated that copper-doped iron had the highest removal rate of 2,4-DNT. The removal rate of 2,4-DNT increased with increasing temperature. After addition of sodium sulfate, the removal rate of 2,4-DNT was enhanced. According to GC/MS analyses, 2,4-diaminotoluene was the final product of 2,4-DNT and possible reductive pathway of 2,4-DNT was proposed.

Abstract: A series of novel multiblock copolymers containing rigid hydrophilic/soft hydrophobic blocks were synthesized and evaluated for use as proton exchange membranes (PEMs). The multiblock copolymers were prepared by a coupling reaction between phenoxide-terminated sulfonated poly(arylene ether sulfone) oligomer (OSO) and fluorine-terminated poly(arylene ether sulfone) oligomer (FNO). All copolymers produced tough, flexible and transparent membranes by casting from DMSO solution. The resulting membranes displayed good water stability and enhanced proton conductivities comparable to that of the corresponding random ones with similar ion exchange capacity (IEC) values. They also showed slight anisotropic swelling behavior, while isotropic behavior for the random ones. The results revealed that these multiblock copolymers were potential candidates for PEM materials.

Abstract: A series of novel sulfonated poly(arylene ether sulfone) (SPAES) copolymers were successfully synthesized from hexafluoro bisphenol A (6F-BPA), 9,9’-bis(4-hydroxyphenyl) fluorene (BHPF), 4,4’-difluorodiphenyl sulfone (DFDPS) and 3,3’-disulfonate-4,4’-difluorodiphenyl sulfone (SDFDPS) via aromatic nucleophilic substitution polymerization, and subsequently used to prepare proton exchange membranes. By adjusting the ratio of 6F-BPA to BHPF, the influence of the rigidity of polymer backbone on the properties of the prepared membranes was investigated in detail. The results indicated that the SPAES membranes had better stability towards water but lowered water uptake and proton conductivity with the increase in the polymer backbone rigidity.

Abstract: The objective of this work was to create 3D hydrogel with tunable degradability for use in tissue regeneration. Therefore, we reported the synthesis and characterization of a novel degradable hydrogel based on poly (amic acid) (PAA). Unlike previously reported degradable hydrogel, these materials contained two kind of cleavable bonds to adjust their degradation. FTIR was employed to characterize the structure of PAA and hydrogels. Swelling ratio and degradation time correlated with the molar ratio of two cross-linkers and cross-linked density. The surface microstructure of hydrogels during degradation was observed by SEM. These properties changed predictably as degradation.

Abstract: As for the more and more severe corrosion fatigue of pipelines in service and the results of the former analyzing means and tests, a new method was brought forward to study the low-cycle corrosion fatigue by using a large pure-bended sample (480 mm×38 mm×12 mm). The experimental samples were obtained from the gas-transmission spiral welded pipe (X65) used in the west-east gas transport project of China. The experiential formula about crack growth speed, , is established via the experimental results under two different environments of air and 3% NaCl solution, and the two constants of a and b were identified.

Abstract: The status and progress of high pressure resistant insulation material at home and abroad were reviewed from aspects like high thermal conductivity, high temperature resistance, environ-mental protection and modification of nano-particles. High thermal conductivity insulation materials can improve the efficiency of cooling system and decrease the energy loss of electric machines. Some famous foreign companies keep ahead in this field. Current domestic high temperature resistant solvent less insulating varnish can only be used in small and medium sized generators instead of high voltage generators. Therefore this kind of material should be improved in either resin rich or resin less insulation systems.

Abstract: Epoxy resin (EP) with excellent performance was widely used as electronic encapsulation materials, but the traditional EP can not meet require of nowadays electronic encapsulation materials in wet-heat resistance, flame retardant, insulation and other performance. So the current research progress of EP with wet-heat resistance and high-performance was summarized in the field of electronic encapsulation.