机载激光雷达测深技术与应用研究进展

近年来机载激光雷达测深技术得到了快速发展,并在近岸海域、河道水深测量以及水下地形地貌测绘等领域发挥了重要作用。详细分析了国内外机载激光雷达测深系统的发展历程,探讨了机载激光测深数据处理和应用方面的研究进展,以及当前机载激光测深技术发展和应用中的问题,最后展望了未来的发展趋势。为机载激光雷达测深技术研究与应用者提供了详细的参考资料。     

ND:YAG透明激光陶瓷的研究进展及相关问题

随着激光技术的进展,对激光介质材料的要求越来越高,大尺寸、高激活离子掺杂度的透明陶瓷材料已经成为国际上的研究热点。从发展历史、粉体的制备、成型以及烧结等方面对Nd∶YAG透明激光陶瓷的研究进展进行总结,并提出了部分需要进一步研究的相关基础问题。     

水体富营养化预警仿真研究及实践

随着我国城镇化进程加快,在城市压力增大、用地继续扩张的背景下,城市规划与管理者对生态环境愈加重视。绝大多数地区在城市规划过程中出于构建生态安全格局、提升区域景观考虑,规划开挖人工湖泊或者小型支流。在城镇中打造人工湖或小型支流作为加强城市水循环、打造水景观的常用手段,兼具实用性、环境改善性与观赏性。     

Microstructural characteristics of Nd:YAG powders leading to transparent ceramics

We reported on the successful synthesis of the Nd:YAG (Nd:Y3Al5O12) nano-powders by using urea as the precipitant with the microwave assisted homogeneous precipitation (MAHP) method. The different microstructural characteristics of the Nd:YAG nano-powders were affected by the concentrations of (Y3++Nd3+) and Al3+ ([Y3++Nd3+]=0.06 mol/L, [Al3+]=0.1 mol/L), aging time (6 d) and aging condition (in vessel). The optimum microstructural characteristics of the high quality Nd:YAG nano-powders leading to transparent Nd:YAG ceramics including the pure YAG phase, the smallest crystallite size, a uniform crystallite size distribution, less density defects, uniform micro-components and the proper molar ratio of (Y3++Nd3+) and Al3+ (0.6148) were discussed.     

Fabrication of cerium-doped nonstoichiometric (Ce,Lu, Gd)3+δ(Ga,Al)5-δO12 transparent ceramics

Cerium-doped nonstoichiometric (Ce,Lu,Gd)3+δ(Ga,Al)5–δO12 (LuGGAG) transparent garnet ceramic samples were fabri-cated via a solid state reaction method in this study. The ceramics were prepared via ox...     

陈化过程中湿度、温度及时间对Nd:YAG纳米粉体的影响

采用微波辅助均相沉淀法制备了Nd:YAG(Nd:Y₃Al₅O₁₂)纳米粉体. 通过XRD和SEM对此方法制备的Nd:YAG纳米粉体进行了分析表征, 并分析了在陈化过程中, 湿度、温度和陈化时间对制备Nd:YAG纳米粉体的影响. 实验结果表明: 陈化环境的湿度、温度和陈化时间对制备Nd:YAG纳米粉体的组分和形貌有显著的影响. 陈化环境中湿度和温度对Nd:YAG纳米粉体的影响具有一定的依存关系, 必须适当地控制; 陈化时间对Nd:YAG纳米粉体的粒径大小影响显著, 随着陈化时间的延长, 获得的Nd:YAG纳米粉体的颗粒尺寸先减小后增大.