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961.
γ-射线辐照HDPE与PA-6共混物的结构与其对二甲苯阻隔性能的关系 总被引:2,自引:0,他引:2
高密度聚乙烯;尼龙-6;相结构;γ-射线辐照HDPE与PA-6共混物的结构与其对二甲苯阻隔性能的关系 相似文献
962.
963.
964.
HU Rong-zu +{ ** } CHEN San-ping + GAO Sheng-li + ZHAO Feng-qi + SONG Ji-rong + SHI Qi-zhen + CHEN Pei + LUO Yang + ZHAO Hong-an + YAO Pu + LI Jing +. Shaanxi Key Laboratory of Physico-Inorganic Chemistry Department of Chemistry Northwest University Xi′an P. R. China . Xi′an Modern Chemistry Research Institute Xi′an P. R. China . Shaanxi Applied Physics-Chemistry Research Institute Xi′an P. R. China 《高等学校化学研究》2004,20(5):631-636
IntroductionLead 2 ,4,6- trinitroresorcinate monohydrate,Pb( TNR)· H2 O,has good detonating propertiesand is sensitive to flame.It can be used as initiat-ing agent,igniter powder or delay powder.Itspreparation,properties,crystal structure[1] andthermal behavior[2 ] have been reported.In the pre-sent paper,we will report its kinetic parametersand mechanism of thermal decomposition reactionstudied with TG- DTA,IR and DSC.This is quiteuseful in the evaluation of its thermal stability un-d… 相似文献
965.
966.
A series of polybenzoxazoles(co)polymers bearing crankshaft units in the main chain was synthesized by the conventional solution polycondensation of 4,6-diaminorescinol dihydrochloride, terephthalic acid (TA) and 2,6-naphthalene dicarboxylic acid(NDA). All of the polymers show lyotropic liquid crystal behavior in polyphosphoric acid (PPA) and methanesulfonic acid (MSA). The polybenzoxazoles exhibit an excellent thermal resistance although the crankshaft monomer has been introduced into the polymer backbone. The temperature for the 5% weight loss of all the polymers is above 600 ℃. The X-ray diffraction analysis results show that the series of the polymers has a high crystallinity. The introduction of NDA makes a slight decrease in the thermal resistance of the polymers. The maximum absorption peak in the UV-Vis spectra can be adjusted according to the amount of 2,6-naphthalene units in the polymers, which indicates the potential application of the polymers as optoelectrie materials. 相似文献
967.
Syntheses of 2- or 6-Substituted Chromones and Chromone Ring-opening Reaction in Polyphosphoric Acid
HEXun-gui YOUQi-dong LIZhi-yu 《高等学校化学研究》2004,20(3):299-304
In an attempt to find new antitumor agents, a novel class of chromone compounds with a benzimidazoleor a benzoxazole ring in positions 2 or 6 were synthesized νia condensation in polyphosphoric acid(PPA) byusing chromone acids as the starting materials. During the preparation process, it was found that PPA couldcleave the chromone ring to produce a ring-opening compound(6). The molar ratio of the chromone com-pound (5) to the ring-opening compound (6) varied with the change of reaction temperature and time. Basedon MTT protocol, the antitumor activity of each of the compounds obtained was evaluated against three hu-man cancer cell lines: KB(oral epidermal), A2780(ovary) and Be17402 (liver). The IC50 varied from 54.7μmol/L to more than 180 μmol/L. 相似文献
968.
969.
Nonempty intersection theorems and system of generalized vector equilibrium problems in product G-convex spaces 总被引:1,自引:0,他引:1
丁协平 《应用数学和力学(英文版)》2004,25(6):618-626
By using an existence theorems of maximal elements for a family of set-valued mappings in G-convex spaces due to the author, some new nonempty intersection theorems for a family of set-valued mappings were established in noncompact product G-convex spaces. As applications, some equilibrium existence theorems for a system of generalized vector equilibrium problems were proved in noncompact product G-convex spaces. These theorems unify, improve and generalize some important known results in literature. 相似文献
970.
In this work the Einstein gravitational field equations and the Lichnerowicz boundary formalism in the extra dimensions are used to build up our black hole model from 6-dimensional space-time. From the internal stress-energy tensor the solutions with energy levels and semiclassical space-quantization are obtained, which combines with only one metric condition outside the defect. We show a new type of energy source, which originates from extra dimensions. A part of the energy source of quasi-stellar object (QSO) maybe come from extra dimensions in that way. The theoretical arithmetic upper limit is identical to that of the output energy of QSO. 相似文献