Blue Laser Diode Pumped Pr~(3+):YLF Visible Lasers

报道了蓝光激光二极管(ld)(中心波长约为444nM)单端纵向抽运掺镨氟化钇锂(Pr3+:ylf)的红光(640nM)和绿光(522nM)激光器。用单个棱镜作为抽运光束整形器,实验中红光最高输出功率为308.5MW,其相应的抽运阈值功率为46MW,斜率效率为47.5%;绿光这三个指标的值相应分别为193.4MW、162.3MW和37.1%。结果表明抽运光的整形提升了红、绿光的输出特性。Red(640 nm)and green(522 nm)lasers with Pr3+:YLF pumped by a blue laser diode emitting at about 444 nm in the longitudinal direction are reported.On the basis of the beam reshaping of the pump spot by aprism,the maximum output power,absorbed threshold pump power and slope efficiency of the red laser are 308.5 mW,46 mW and 47.5%,respectively.The three corresponding parameter values for green laser are 193.4 mW,162.3 mW and 37.1%,respectively.The results show that the shaped pump beam is beneficial to improve the output characteristics of these two visible laser emissions.国家自然科学基金(61275050); 博士点基金(20120121110034); 厦门市科技项目(3502Z20113004

On the strategies and approaches of high-quality development of coastal ecological farm and ranch in the Yellow River Delta

The Yellow River Delta is rich in natural resources and has a unique ecosystem.The ecological protection and high-quality development in the Yellow River Delta have become a national strategy.Under the severe constraints of resources and environments as well as the serious degradation of ecosystems,the ecological protection and high-quality development of the Yellow River Delta urgently need the guidance and support of scientific and technological innovation.The implementation of coastal ecological farm and ranch is considered to be one of the important ways to achieve high-quality development.In order to create new models of green,low-carbon and circular coastal ecological farm and ranch in the Yellow River Delta,this paper analyzed the existing problems in coastal ecological farm and ranch,and put forward the high-quality developmental concepts and targets.At present,the unoptimized macroscopical planning,the incomplete industrial system,the imperfect innovation system,and the unstrengthened policy support of coastal ecological farm and ranch have restricted the high-quality development of coastal ecological farm and ranch in the Yellow River Delta.Furthermore,multi-driven high quality development approaches were raised as follows.Firstly,optimizing the macroscopical planning driven by watersalt scenario,that is,identify the complexity of the water-salt scenario and plan the layout reasonably;analyze the dynamics of the water-salt scenario and accomplish digital management.Secondly,highlighting the chip function driven by seed industry,that is,improve biodiversity based on native species protection;strengthen the cultivation of improved seed to enhance the driving force of industry;promote seed breeding to improve the coverage of seed industry.Thirdly,promoting model innovation driven by farm-aquaculture interaction,that is,connect land and sea to optimize industrial spatial layout;integrate farm and ranch,and establish linkage between Three Industries.Fourthly,realizing the intelligent upgrading of industry driven by equipment development,that is,build unmanned farms in saline and alkaline land;realize less populated farms and ranches on the tidal-flat area;create shallow sea intelligent ranches.Fifthly,innovating the collaborative paradigm driven by research-industry linkage,that is,integrate innovative elements to solve the problem of disconnection between industry and scientific research;financing through multiple channels to enhance innovation vitality.Finally,achieving industrial upgrading driven by governance policy,that is,integrate research and development resources and improve innovation ability;implement integrated development and strengthen the whole industrial chain;forward-looking layout of special research projects and innovative development modes.Therefore,stakeholders could construct new developmental models of coastal ecological farm and ranch in the Yellow River Delta with match of water-salt scenarios,integration of farm and ranch,and linkage of Three Industries,to realize the coordinated development of mechanization,intelligence,digitization and systematization.Our study is helpful to provide a reference for the high-quality development of coastal ecological farm and ranch in the Yellow River Delta