从浅攻到蚕食:论章楶的军事构想与实施

章楶,建州蒲城(今福建蒲城)人,北宋哲宗时历任环庆路、泾原路安抚使,主持西北军务,颇有战功,为"一时良将"。哲宗朝是北宋对西夏在军事、外交方面的战略转变时期,在元祐年间,章楶的防御战略抵御了西夏来犯,而绍圣、元符年间,他的进攻战略使得北宋军队大举反攻,拓边西北。本文对章楶在不同时期所陈军事战略以及具体实施进行探讨。

Sharp Bounds for Symmetric and Asymmetric Diophantine Approximation

In 2004,Tong found bounds for the approximation quality of a regular continued fraction convergent to a rational number,expressed in bounds for both the previous and next approximation.The authors sharpen his results with a geometric method and give both sharp upper and lower bounds.The asymptotic frequencies that these bounds occur are also calculated.