对二苯并-30-冠-10(DB 30 C 10)和苯并-15-冠-5(B 15 C 5)的紫外分光光度测定法进行了研究。结果表明,DB 30 C 10在2.0×10^(-5)～2.4×10^(-4)mol/L 和 B 15 C 5在3.40×10^(-9)～4.1×10^(-4)mol/L 范围内遵守比耳定...对二苯并-30-冠-10(DB 30 C 10)和苯并-15-冠-5(B 15 C 5)的紫外分光光度测定法进行了研究。结果表明,DB 30 C 10在2.0×10^(-5)～2.4×10^(-4)mol/L 和 B 15 C 5在3.40×10^(-9)～4.1×10^(-4)mol/L 范围内遵守比耳定律。给出了两种试剂在不同溶液中的λ_(max)和ε值。展开更多
Hilbert problem 15 required understanding Schubert's book.In this book,reducing to degenerate cases was one of the main methods for enumeration.We found that nonstandard analysis is a suitable tool for making rigo...Hilbert problem 15 required understanding Schubert's book.In this book,reducing to degenerate cases was one of the main methods for enumeration.We found that nonstandard analysis is a suitable tool for making rigorous of Schubert's proofs of some results,which used degeneration method,but are obviously not rigorous.In this paper,we give a rigorous proof for Example 4 in Schubert's book,Chapter 1.§4 according to his idea.This shows that Schubert's intuitive idea is correct,but to make it rigorous a lot of work should be done.展开更多
The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness,...The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.展开更多
文摘对二苯并-30-冠-10(DB 30 C 10)和苯并-15-冠-5(B 15 C 5)的紫外分光光度测定法进行了研究。结果表明,DB 30 C 10在2.0×10^(-5)～2.4×10^(-4)mol/L 和 B 15 C 5在3.40×10^(-9)～4.1×10^(-4)mol/L 范围内遵守比耳定律。给出了两种试剂在不同溶液中的λ_(max)和ε值。
文摘Hilbert problem 15 required understanding Schubert's book.In this book,reducing to degenerate cases was one of the main methods for enumeration.We found that nonstandard analysis is a suitable tool for making rigorous of Schubert's proofs of some results,which used degeneration method,but are obviously not rigorous.In this paper,we give a rigorous proof for Example 4 in Schubert's book,Chapter 1.§4 according to his idea.This shows that Schubert's intuitive idea is correct,but to make it rigorous a lot of work should be done.
文摘The key problems of cold power spinning of Ti-15-3 alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.
