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对于函数的概念,苏教版必修数学1是站在集合观点上给出的,一般地,设A,B是两个非空数集,如果按某种对应法则f,对于集合A中的每一个元素x,在集合B中都有惟一的元素y和它对应,这样的对应叫做从A到B的一个函数,通常记为y=f(x),x∈A,其中所有的输入值x组成的集合A叫做函数y=f(x)的定义域,对于A中的每一个x,都有一个输出值y与之对应,我们将所有输出值y组成的集合称为函数的值域. 相似文献
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Two novel adducts of formula Mn(hfac)2( NITPhCl )2 (1) and [Mn(hfac)2(IMHPhCl)]2(NIT-PhCl)·0.5H2O (2), where hfac = hexafluoroacetylacetonate, NITPhCl = 2-(3-chlorophenyl)-4,4,5,5-tetram-ethylimidazolyl-1-oxyl-3-oxide, IMHPhCl = 2-(3-chlorophenyl)-4, 4, 5, 5-tetramethylimidazolyl-3-oxide, have been prepared by the reaction of Mn(hfac)2·2H2O with NITPhCl. Compound 1 is triclinic, space group P-1with a = 1.3003(3) nm, 6 = 1.3138(3) nm,c = 1.4931 (3) nm, α = 83.74(3)°, β = 77.77(3)°, γ = 60.59(3)°, V=2.171(1)nm3, Z = 2. Compound 2 is triclinic, space group P-1 with a = 1.2994(3) nm, b = 1.4841(3) nm, c = 2.1031 (4) nm, a = 92.30(3)° ,p = 98.68(3)°, γ = 97.89(3)°, V= 3.964(2)nm3, Z = 2. Each manganese atom is hexacoordinated in both compounds and compound 2 is organized inchains by hydrogen bonds between neighboring pairs of NITPhCl and IMHPhCl. 相似文献
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一、引发类比、联想,培养想象思维
类比、联想是发展想象思维的前提,在课堂教学中,教师要时刻引导学生用已有的知识经验,诱发未知的想象,来培养学生的想象思维.据传,春秋时代鲁国的公输班受到路边的齿形草能割破行人的腿的启发,发明了锯子.他的思维过程可能为:齿形草能割破行人的腿,“锯子”能“锯”开木材, 相似文献
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