市井”含有“街市、市场”以及“粗俗鄙陋”之意。市井文化是一种生活化、自然化、无序化的自然文化，它是指产生于街区小巷、带有商业倾向、通俗浅近、充满变幻而杂乱无章的一种市民文化，它是一种“现象流”——“逝者如斯乎，不舍昼夜。”它反映着市民真实的日常生活和心态，表现出浅近而表面化的喜怒哀乐。它自由闲散缺乏庄严，缺少深刻性和心灵冲击力，“没有现实与历史的深层次的忧患，更没有血与火的悲剧意识。”

To your second request: I had done some searches but obtained no result.Usually in China we use 知网,a site of essay data in various fields which is not open publicly if you have not been signed and pay.There is very few other sites you could turn to. I found only one related article maybe it could be helpful to you: 黄发有：<<90年代小说的城市焦虑>> http://www.ddwenxue.com/html/wxjy/xwlw/20080609/107.html

市井is a derogatory term before.like 市井小民(shi jing xiao min)，means ordinary people who are not very rich or have much power,generally,the speaker is look down at someone with prejudice.but now it's almost neutral word.市井文化 is related to common people's culture,it's based on daily life,rife in city. yeah.it's my personal opinion...

文化=culture it's easy to understand 市井 maybe it's equal to the ordinary and common ppl who have no high social status. popular literature or art can be replace this word