In this paper, the structure evolution in ¹⁵⁸Er and¹⁸⁵Os isotopes is calculated using the projected shell model (PSM) framework. The yrast spectrum, nucleon-rich effects, back-bending phenomenon, and the ratio of reduced electromagnetic transition probabilities, B(M1)/B(E2), are calculated in the spins ranges 8⁺–22⁺ and 17/2⁺–45/2⁺ for the mentioned isotopes, respectively. In the yrast spectrum, band crossing of one, two, and three quasi-particle bands at spins around 12⁺ and 41/2⁺, which is a sign of nucleon alignments, is investigated and 27 additional nucleons are found to be the reasons for back bending at lower spins in ¹⁵⁸Er than ¹⁸⁵Os, which is coincident with two great drops in the B(M1)/B(E2) ratio plots.

在本文中，使用投影壳模型（PSM）框架计算了¹⁵⁸ Er和¹⁸⁵ Os同位素的结构演化。在自旋范围8 ⁺ –22 ⁺和17/2 ⁺ –中计算了拉斯特谱，富核子效应，反弯曲现象以及降低的电磁跃迁几率B（M1）/ B（E2）。提到的同位素分别为45/2 ⁺。在yrast光谱中，研究了自旋1、2和3个准粒子带在12 ⁺和41/2 ⁺附近的自旋，这是核子比对的标志，另外27个核子是造成这种现象的原因。在较低的旋转中向后弯曲¹⁵⁸ Er比¹⁸⁵ Os，这与B（M 1）/ B（E 2）比图中的两个大滴重合。