It has been wildly accepted that it is a good idea to search new genes from these uncultured microorganisms during the course of study to isolate new genes from total dnas prepared from uncultured bacteria in soil , we obtained a 4 . 7 - kb dna fragment that made e . coli host cells produce a red fluorescence light under exposure of ultraviolet ( uv ) 在研究和开发未能培养的微生物的过程中，从土壤细菌中克隆到一条全长4 . 7kb的dna片段，与质粒puc118连接后转入大肠杆菌jm109菌株中，其编码的产物可以使重组菌体在紫外线照射下呈现红色荧光。将基因称为红色基因( redgene ) ，含该基因的重组菌称为red - clone 。
Due to the large exciton binding energy of 60mev , which ensures the high efficient excitonic emission at room temperature , it is regarded as one of the most promising materials for fabricating efficient ultraviolet ( uv ) and blue light emitting devices . since the first observation of the stimulated ultraviolet emission at room temperature , zno has become another hotspot in the region of uv light emitting researching 氧化锌在室温条件下具有较高的激子束缚能( 60mev ) ，保证了其在室温下较强的激子发光，是制作紫外光电子器件的合适材料，自1997年首次发现zno室温紫外受激发射以来， zno研究已成为继gan之后紫外发射材料研究的又一研究热点。
The lifetime of particles co - doped with li + and na + increased as compared to that of un - doped one . however , the lifetime decreased as co - doped with other dopants . in addition , we also studied that ultraviolet ( uv ) light - induced spectral change in eu3 + - doped aluminosilicate glass and red to blue up - conversion emission of tm3 + - , yb3 + - doped y2o3 nanocrystals ( 2 )在紫外光辐照下， eu ~ ( 3 + )掺杂的氧化物玻璃电荷迁移带强度降低，通过研究辐照与激光的功率密度、波长的关系，发现这种变化属于单光子过程，并具有频率选择性。
Due to the large exciton binding energy of 60mev , which ensures the high efficient excitonic emission at room temperature , it is regarded as one of the most promising materials for fabricating efficient ultraviolet ( uv ) and blue light emitting devices . since the first observation of the stimulated ultraviolet emission at room temperature , zno has become another hotspot in the region of uv light emitting researching 由于氧化锌在室温条件下具有较高的激子束缚能( 60mev ) ，保证了其在室温下较强的激子发光，因而被认为是制作紫外半导体激光器的合适材料，自1997年首次发现zno室温紫外受激发射以来， zno研究已成为继gan之后紫外发射材料研究的又一研究热点。
Dlc and a - sic : h films were prepared by the rf glow discharge and the reactive sputtering method respectively . there were two reasons that we chose y rays , ultraviolet ( uv ) photons , and neutrons as radiation sources . one is that y rays , uv photons and neutrons irradiation are serious at outer space and / or nucleus irradiation enviromentthe other is that the study on y rays irradiation on the films is a new and an important directioaotherwisejirnited reports have been made of the investigation on the uv photonsjieutrons irradiation influences on these films 本文分别采用射频( 13 . 56mhz )等离子体cvd及射频反应溅射方法制得了dlc及a - sic ： h薄膜。文中主要选择y射线、紫外光及中子作为辐照源有两方面的原因：一方面，在外层空间， y射线及紫外光辐射十分严重，而在核辐射环境下y射线及中子辐射也不可忽视；另一方面， y射线辐照这两种薄膜完全是一项开创性的工作，同时国内外对紫外光子、中子与这两种薄膜作用的研究也很少。
In fact , gan has been regarded as one of the most promising materials for the fabrication of opto - electronic devices operating in the blue and near - ultraviolet ( uv ) regions , for instance light - emitting diodes ( leds ) and laser diodes ( lds ) , because it has large direct energy band gap of 3 . 4ev at room temperature Gan是一种十分优异的宽带隙-族化合物半导体材料，是当前世界上最先进的半导体材料之一。室温下， gan的禁带宽度为3 . 4ev ，是制作光电子器件，尤其是蓝、绿发光二极管( leds )和激光二极管( lds )的理想材料。
