There has been compelling evidence indicating that deformed single-particle (SP) states in neutron-rich regions are different from those in the stable region. It was pointed out that for the light rare-earth (60Nd, 62Sm, and 64Gd), neutron-rich (N = 98 − 102) nuclei, the Woods–Saxon potential, the Nilsson modified oscillator potential with ‘universal’ parameters, and the folded Yukawa potential all failed to describe the correct ordering of neutron SP states. The location and size of deformed shell gaps in this mass region are under current debate. We propose a modification for the ‘standard’ Nilsson parameters of Bengtsson and Ragnarsson introduced in 1985. The proposed N-dependent spin–orbit interaction causes directly changes in deformed shell gaps with neutron number and deformation. By applying the modified Nilsson parameters to generate deformed bases for the projected shell model, we demonstrate that the calculation can explain consistently the current experimental data, including the ground state configuration in odd-neutron nuclei, upbending of the yrast moment of inertia at higher spins and the energies of 2-quasineutron 6− and 4− isomers in even–even nuclei.

The oil spills occur frequently during the offshore oil exploration and transportation, resulting in the destruction of the marine environment. After an oil spill, petroleum can stay in the sea for a long time and pose a toxic effect on marine organism. Under the action of the waves, oil continues to diffuse, flows to the intertidal zone of the coast, where it accumulates. Ulva pertusa Kjellman (Ulvales, Chlorophyta) is the marine green algae and is widely distributed and easy to breed in the intertidal zone. The study investigated the growth rates, chlorophyll-a, and carbon and nitrogen stable isotopes of U. pertusa under the stress of the water accommodated fraction (WAF) for two kinds of oils (0# diesel oil and Russian crude oil). The results showed that the growth rate and chlorophyll-a initially increased and then decreased under the stress of WAF. High concentration of WAF posed the obviously inhibitory effect on algae; and oil spill also causes the distinct fraction of carbon and nitrogen stable isotopes of U. pertusa, especially for carbon stable isotope. The change trends of bulk carbon and nitrogen isotopes were similar to those of growth rates of U. pertusa. Therefore, the application of stable isotope techniques can quickly evaluate the toxic effects of petroleum on algae and can be used as a new method to evaluate the toxicity of the oil spill in marine environment.