The relationship of this geometry to Riemann's varieties was not clear.这种几何和Riemann几何的关系是不清楚的.H. C. Whitehead theorem in Riemann manifolds is extended into Finsler manifolds.指出了Finsler流 形中任一点处凸邻域的存在性,将Riemann流形的J. H...
The relationship of this geometry to Riemann's varieties was not clear.这种几何和Riemann几何的关系是不清楚的.He could not understand Riemann's work on Abelian functions nor Roch's contributions in his dissertation.他不能理解R...
Evolution can explain why human embryos look like gilled fishes.进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样.A sharp demarcation of adventive embryos from zygotic embryos cannot be drawn.不定胚与合子胚之间不能划分出明显的界限.Most grass embryos have a fla...
以硫酸氢钾为催化剂,正丁酸和异戊醇为原料合成了正丁酸异戊酯.Isoamyl butyrate was synthesized by using potassium bisulfate as the catalyst.以硫酸高铈为催化剂,正丁酸和异戊醇为原料合成了正丁酸异戊酯.Isoamyl butyrate was synthesized by using ceric sulfate as the catalyst.以硫酸铈铵为催化剂,...