Effects of Lu^(3+ )Doping on Optical Properties and Laser Performances of NYAB Crystal

Volume compensation(VC)achieved in(Lu,Nd):YAl_(3)(BO_(3))_(4)(YAB)crystal codoped with Lu^(3+)and Nd^(3+)ions is described.The lattice parameters,spectral properties and laser performances of the VC(Lu,Nd):YAB and single-doped Nd:YAB(NYAB)crystals are measured and compared.The results indicate that the laser performances of NYAB crystal can be greatly improved by the VC doping.

气缸体铸件裂纹缺陷的分析及解决

介绍了16 L天然气发动机气缸体铸件的结构及技术要求,针对试制过程中在铸件通风口之间的位置出现的裂纹进行了分析,并结合计算机模拟技术,分析铸件的凝固过程和应力情况,确定了裂纹的类型为冷裂纹。通过优化铸件结构,避免在铸件上形成应力集中,增加铸件应力处的结构强度,改善型芯的退让性或溃散性,减小铸件的收缩阻力,降低材料的收缩倾向,减少铸件的内应力,合理调整熔炼工艺等措施,解决了铸件的裂纹问题。