但是自身条件的不足和社会环境的种种限制，就像一道道有形无形的门槛不断粉碎着他们的城市梦，阻碍了其自我价值的实现。
But the constraints of their own conditions and social environment are the obstacles for its realization as they break down their dreams in the city.
这为它今后能迈进钱币收藏领域三星级的门槛奠定了基础，也是很多收藏家鉴定票券是否有收藏价值的首要条件。
This for it will be towards the threshold of the coin collection field three-star laid a foundation, is also a lot collectors identify whether there be collection value in the workplace.
采用恒载荷和慢应变速率动态拉伸实验方法，测定了X80管道钢在不同充氢条件下的氢致开裂门槛应力和断裂应力。
The threshold stress and fracture stress of hydrogen-induced cracking of X80 pipeline steel are studied by constant load test and slow stain rate test.
应用推荐