原子核电荷半径R_c所有的实验数据都表明,R_c系统偏离A~(1/3)律,即随A增大R_c/A~(1/3)系统地递减,而R_c/Z~(1/3)则比较接近于一个常量.原子核巨单极共振能量E_x∝R~(-1)的大量实验数据也支持这一结论.根本原因在于A~(1/3)律与同位旋无关,而Z~(1/3)律已部分反映了同位旋的影响.基于壳模型,给出了Z~(1/3)律的微观诠释.壳模型中质子和中子谐振子势强度参数ω_p和ω_n的差异,可以用Z~(1/3)律说明.基于与Wigner的原子核同位旋多重态质量公式(IMME)相似的理论考虑,提出了核电荷半径改进的Z~(1/3)律. All the experimental data of the nucleus charge radius R_c show that the R_c system departs from A ~ (1/3) law, that is, decreases systematically as R increases, while R_c / Z ~ (1/3) ) Is quite close to a constant.The large number of experimental data of nuclear monopole resonance E_xαR ~ (-1) also support this conclusion.The fundamental reason is that A ~ (1/3) law has nothing to do with isospin, and Z The ~ (1/3) law has partially reflected the isospin effect. Based on the shell model, the microscopic interpretation of the Z ~ (1/3) law is given. The proton and neutron resonance oscillator strength parameters ω_p and ω_n The Z ~ (1/3) law can be used to explain the difference of Z / (1/3) law of nuclear charge radius based on the similar theory of Wigner’s nuclear isospin-like multiplex mass state formula (IMME)