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71.
In the present study, the regional characteristics of continental seismic activity, the relationship between continental seismic activity and plate tectonics as well as the processes of evolution of large earthquakes in the seismic regions have been discussed, on the basis of the data of earthquakes with M≥6 widely distributed over Central and Eastern Asia continent, the fault plane solutions of great shallow earthquakes and the information on the geological structure of this continent as well. 相似文献
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在中专物理中常常会遇到一些极值问题,例如两物体发生完全非弹性碰撞时动能损失最大,负载电阻等于电源内阻时电源输出功率最大,实验中滑动触头在电桥电阻丝中点附近时实验误差最小等等.至于在物理习题中,则极值问题更是比比皆是.可见,极值问题是中专物理无法避开的问题.本文对中专物理中用初等数学知识处理极值问题的一些常用方法归纳如下:1 利用三角函数的性质本法主要利用正弦函数和余弦函数的极值为±1的原理作为求极值的依据.凡与三角函数有关的极值问题,如将有关表达式化成包含单个正弦函数或余弦函数的式子,然后运sl… 相似文献
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3-OXaperfluoroalkanesulfonyl fluoride (1) reacted with allylamine to give the corresponding N-allylsulfonamide 2 which on treatment with sodium methoxide and methyl iodide affrded N-methyl-N-allyl-3 -oxaperfluoroalkanesulfonamide 3. 2 and 3 were converted to the corresponding substituted trichlorosilanes 4 and 5 respectively on treatment with trichlorosilane in the presence of chloroplatinic acid. Compounds 5 reacted with methanol and pyridine to give the corresponding trimethoxysilane 6. The elemental analysis, IR, ^1H NMR and 19F NMR data of these new compounds were recorded in Table 1-4. The compounds 4, 5 can be used for the treatment of glass surface to render it water-proof and solvent-proof. 相似文献
78.
The reaction of perfluoro- (3, 4-dimethyl-3-ethylhexene-(2)) (1) with allyl alcohol under different conditions gave different products. Compound 1 reacted with sodium allyl alcoholate yielding 2-(1'-allyloxy-tetrafluoroethyl)-perfluoro(3-methyl-3-ethylpentene- (1))(2). In the presence of triethylamine, 1 reacted with allyl alcohol to give 2-allyloxy-perfluoro (3, 4-dimethy1-4-ethylhexene- (2))(3), and in the presence of acetone and K2CO3 to give compound 4. These reactions all gave allyl-3-trifluoromethyl-3- pentafluoroethyl-2,2-dihydro-pentafluorovalerate (5a) as byproduct. Compound 1 reacted with allyl alcohol in the presence of triethylamine at 20-22`C to give 2, at 30-35`C to give a mixture of 2 and 3 and at 35-40`C to give a mixture of 3 and 5a respectively. Compound 2 was transformed to compound 4 in acetone and in the psesence of K2CO3, \o\ compound 5a or 5b in the corresponding alcohol and to compound 6 on reacting with dimethylamine. Compound 2 as well as 3 was converted to perfluoro-(3-ethyl-2,3,4,5- tetramethyl-2,3-dihydrofuran) (7) by KF in sulpholane. 相似文献
79.
3, 4-Bis (trifluoromethyl)-perfluorohexene-(3) (1) reacted with diethylamine to give the 1-N, N-diethylamino-2-pentafluoroethyl -3-trifluoromethyl-perfluoropentene-(1)(2), which was easily hydrolyzed to the corresponding N, N-diethyl-2-penta-fluoroethyl- 3-trifluoromethyl-perfluoropenteno-(2)-amide (3). When compound 1 was allowed to react with n-butyl amine at 40-50`C, the 2,3,4-tris(trifluoromethyl)-4-pentafluoroethyl-1-n-butyl-aza- cyclobutene-(2) (5) was obtained as the main product and at-30-40`C, 3,4-bis(trifluoromethyl)-4-n-butylamino-perfluorohexene-(2) (4) as the main product. The isomers 3, 4-bis(trifluoromethyl)-4-allyloxy-perfluoro-hexen-(2) (6) and 2-pentafluoroethyl-3-trifluoromethyl-3-allyloxy-perfluoropentene-(1)(7) were formed when 1 was reacted with sodium allyl alcoholate. 相似文献
80.
金属组学是一门新兴的前沿交叉学科,是对若干涉及金属相关生命过程的分子机制以及对细胞与组织内全部金属离子和金属配合物进行综合研究的学科.在金属组学中,生命体系中所有的金属蛋白质、金属酶以及其他含金属的生物分子统称为金属组,这个概念与基因组学中的基因组和蛋白质组学中的蛋白质组相类似.本文对金属组学中涉及的若干概念进行阐述,并将着重介绍金属组学中的研究技术和方法,特别是“组和技术”,即把一种高分辨率分离技术如凝胶电泳/激光切除、色谱或者毛细管电泳与一项高灵敏度检测方法,如电感耦合等离子体质谱、电喷雾电离质谱、基质辅助激光解吸附质谱或者X射线荧光/吸收光谱联合起来.并重点分析了这些方法的优缺点以及在分离鉴别金属蛋白、磷酸化蛋白以及硒蛋白、确定金属蛋白的结构与功能的关系和医药中的金属药物活性抗药性方面的研究中的应用. 相似文献