A century on from Dmitrii Mendeleev: tables and spirals,noble gases and Nobel prizes

Mendeleev’s failure to represent the periodic system as a continuum may have hidden from him the space for the noble gases. A spiral format might have revealed the significance of the wide gaps in atomic mass between his rows. Tables overemphasize the division of the sequence into ‘periods’ and blocks. Not only do spirals express the continuity; in addition they are more attractive visually. They also facilitate a new placing for hydrogen and the introduction of an ‘element of atomic number zero’.

New upper bounds on Lee codes

The paper considers exact values of and upper bounds on the maximal cardinality of a q-ary Lee code of length n with a minimum distance ?d. Special attention is paid to small parameters. Some new results are presented and tables with the presently known best upper bounds are given for q∈{5,6,7} and n?7.     

用对数线性模型比较香港居民在超市与便利店的购买行为

对于抽样调查比较香港居民在超市与便利店的购买行为所得的配对设计的方列联表数据，用对数线性模型进行分析。