Celibacy is considered as one of the greatest virtues of a student seeking knowledge.
What are the methods proposed by Hindu scriptures, by which a student can keep his/her celibacy or practice of abstinence intact, in this new age?
You can't practice Brahmacharya just by reading books or making vows. You are containing Vasanas or Samskarans from eons into/onto your chitta. There are three layers of mind - conscious, sub conscious & unconscious. By force or temporary Vairagya you can only control your conscious mind but the habits patterns which are present in deep layers of mind (namely in other twos) can't be destroyed so easily without a particular organized method or practice. To eradicate Samskarans from deep mind you will have to practice awareness & equanimity. There are many meditations for this which you can find in Vijanabhairava tantra. Buddhist's techniques Vipassana & satipatthan are also for the same. You can find the way in this answer.
8 things to avoid in order to maintain strict brahmacharya by Sridhara Swami - http://selfdefinition.org/celibacy/quotes/sridhar-swami-eight-aspects-of-brahmacharya.htm
It also greatly helps if you avoid rajasic/tamasic foods - meat, liquor, onion & garlic - because they stimulate nerves & sexual desires.