当代大学生创业风险及防范研究

目前我国大学生创业状态和盈利情况不容乐观，研究大学生创业风险种类，能够更好地对风险产生的原因进行分析，做出有效的防范措施。大学生创业风险可根据经营活动划分为不同的风险类型，创业风险产生原因主要有大学生自身知识和能力存在不足、学校创业教育存在短板、社会舆论存在过度宣传和误导、大学生创业风险防范体系不够完善等，需要从学生自身、高校教育、社会舆论、法律制度建设等方面防范大学生创业风险。     

Effect of RE on molybdenum partitioning and resultant mechanical and microstructuralbehaviorofaduplexstainlesssteelduringhotworkingcondition

The effect of rare earth(RE) on Mo partitioning and resultant mechanical and microstructural behavior of a duplex stainless steel during hot working condition was investigated. It was found that RE effect was sensitive to temperature. At the high temperature, the development of dynamic recovery(DRV) in α phase was slowed down while the dynamic recrystallization(DRX) process in γ phase was accelerated by RE, whereby both work hardening rate(at low strain) and dynamic softening rate(at high strain) increased and moreover, the discrepancy on the hardness of the both phase reduced. Whereas at the low temperature, the effect of RE was opposite as compared with those in the high temperature. Mo partitioning analysis by EPMA indicated that RE enhanced the partitioning of Mo in α phase while reduced Mo concentration in γ phase at higher temperature whereby the mismatch between two phases could be improved indicated by the elimination of voids and cracks at α/γ interface, but it was contrary to that at the low temperature. Mo partitioning was believed to be an important cause for the RE effect on the differences of mechanical and microstructural behavior. Also this result provided a reasonable evidence for micro-alloying of RE in DSSs.     

石油压裂阀箱用17-4PH不锈钢热变形行为及热加工图

利用Gleeble-3500热模拟试验机研究了石油压裂阀箱用17-4PH不锈钢在变形温度为1050～1250℃,应变速率为0.01～0.5 s-1区间的热变形行为.结果表明:试验钢热变形流变曲线呈现出典型的动态再结晶特征,最大变形抗力随着变形温度的升高和应变速率的降低而减小,表明动态再结晶更充分.通过回归计算获得了17...