Lecturer 在不同国家意思差别还挺大的
在英国:
A lecturer in UK universities usually holds an open-ended position that involves carrying out both teaching and research. After a number of years, a lecturer may be promoted and become a senior lecturer. This position is below reader and professor.
在美国:
On a generic level, the term broadly denotes one who teaches at a university but is not eligible for tenure and has no research obligations.
assistant professor 在美国是入门的教职,非tenure
The rank of assistant professor generally is held for a probationary period of three to seven years,[13] after which the individual will either be promoted to associate professor and granted tenure (i.e., cannot be fired without cause and a formal hearing process) or will be terminated from employment.
在中国的话,大家都比较熟悉了:
Principal faculty
Professor (Chinese: 教授)
Associate professor (Chinese: 副教授)
Lecturer, or University Lecturer (Chinese: 讲师)
Assistant lecturer, or Associate lecturer (Chinese: 助教)
以上复制自维基百科
楼主的问题是说中国大学的assistant professor和lecturer之间的区别,我觉得其实就是我们所说的讲师,
但是稍有区别的地方在于:
1.有些学校开始执行非升即走的制度,也就是类似于美国的tenure制度,那么一般就都是先拿助理教授的职务,但是有些学校也就叫讲师,几年之内(国内五年比较多)拿不到副教授职务,就得离开再找工作。
2.还有没改革的学校的讲师是终身的。
3.另外讲师会有可能不做研究的歧义。
所以相对而言,刚博士毕业(或刚博士后出站)还未拿到副教授职位的教学科研人员,我认为中文就叫做讲师,英文翻译为assistant professor可能更为合适