位阻效应 meaning in English

steric effects

Dense of structure and development of final properties were benefited from retardation of hydration . in contrast , cement hydration process was controlled better by polycarboxylate superplasticizer than the other three superplasticizers owing to its stereoscopic action . and its adaptability to cement was better , by which the cement particles were
相比之下,聚羧酸盐高效减水剂由于其良好的空间位阻效应,能够使水泥颗粒呈完全分散状态,与其他三种高效减水剂相比可有效控制水泥水化历程,与水泥适应性较好。
The membrane properties were found to be dependent upon the content of styrene . the membrane physic - chemical properties compare to nafion 117 except that their chemical stability has to be further improved to make them acceptable for practical use in the proton exchange membrane fuel cell . the proton transport through the membrane follows the " liquid - like " proton conductivity mechanism y and the water balance is important for the working condition of the fuel cell
对磺化膜的研究分析表明：膜的性能参数如离子交换容量、吸水率、水合系数、形体稳定性、导电性能、化学与热稳定性等依赖于膜中苯乙烯含量，且接枝苯乙烯相互间的位阻效应对膜性能影响很大；膜的性能可与nafion膜相比较；质子在膜中的传导遵循“似液体”质子传导机理；电渗析与扩散作用使膜保持水平衡。