In this paper,the theoretical rate equation model of an in-band pumped gain-switched thulium-doped fiber(TDF) laser is investigated.The analytical formulations of pump energy threshold,peak power extraction efficiency...In this paper,the theoretical rate equation model of an in-band pumped gain-switched thulium-doped fiber(TDF) laser is investigated.The analytical formulations of pump energy threshold,peak power extraction efficiency,and pulse extraction efficiency are derived through analyzing the interaction process between the pump pulse and the laser pulse.They are useful for understanding,designing,and optimizing the in-band pumped TDF lasers in a 1.9 μm-2.1 μm wavelength region.The experiment with an all-fiber gain-switched TDF laser pumped by a 1.558-μm pulse amplifier is conducted,and our experimental results show good agreement with theoretical analysis.展开更多
Cotton fiber strength is mainly determined during the secondary cell wall deposition stage when cel- lulose is synthesized. We obtained cDNA of 20―25 d post anthesis (DPA) fiber from 109 F2 progeny and developed a co...Cotton fiber strength is mainly determined during the secondary cell wall deposition stage when cel- lulose is synthesized. We obtained cDNA of 20―25 d post anthesis (DPA) fiber from 109 F2 progeny and developed a cotton fiber transcriptome profiling via cDNA-AFLP technology using 37 different primer combinations. The F2 population originated from an interspecific cross between Gossypium hirsutum and Gossypium barbadense. One hundred and thirty-eight absence/presence polymorphic transcript- derived fragments (TDFs), with sizes ranging from 100 bp to 722 bp, were screened. Of these, 75 (53.62%) were polymorphic between the parents of the F2 population. Sequencing the 75 transcripts revealed that 37 of them had been reported to be cotton fiber ESTs. Nine of 75 transcript sequences were homologous to 7 cloned cotton fiber genes, encoding cysteine proteinase, vacuolar H+-pyro- phosphatase, vacuolar H+-ATPase, catalytic subunit, arabinogalactan protein, putative receptor protein kinase PERK1, GIA/RGA-like gibberellin response modulator and cellulose synthase. Some other transcripts may represent new gene fragments in cotton fiber development. Surprisingly, 46 of the 75 transcripts were mapped to a single linkage group. The transcriptome groups and the sequenced TDFs could serve as important resources in the functional genomic research of cotton fiber development.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 60878011 and 61078008)the Program for New Century ExcellentTalents in University,China (Grant No. NCET-10-0067)
文摘In this paper,the theoretical rate equation model of an in-band pumped gain-switched thulium-doped fiber(TDF) laser is investigated.The analytical formulations of pump energy threshold,peak power extraction efficiency,and pulse extraction efficiency are derived through analyzing the interaction process between the pump pulse and the laser pulse.They are useful for understanding,designing,and optimizing the in-band pumped TDF lasers in a 1.9 μm-2.1 μm wavelength region.The experiment with an all-fiber gain-switched TDF laser pumped by a 1.558-μm pulse amplifier is conducted,and our experimental results show good agreement with theoretical analysis.
基金Supported by the National 973 Project (Grant No. 2004CB117302)the National Natural Science Foundation of China (Grant No. 30671322)the Key Project of Natural Science Foundation of Hebei Province (Grant No. C2006001034)
文摘Cotton fiber strength is mainly determined during the secondary cell wall deposition stage when cel- lulose is synthesized. We obtained cDNA of 20―25 d post anthesis (DPA) fiber from 109 F2 progeny and developed a cotton fiber transcriptome profiling via cDNA-AFLP technology using 37 different primer combinations. The F2 population originated from an interspecific cross between Gossypium hirsutum and Gossypium barbadense. One hundred and thirty-eight absence/presence polymorphic transcript- derived fragments (TDFs), with sizes ranging from 100 bp to 722 bp, were screened. Of these, 75 (53.62%) were polymorphic between the parents of the F2 population. Sequencing the 75 transcripts revealed that 37 of them had been reported to be cotton fiber ESTs. Nine of 75 transcript sequences were homologous to 7 cloned cotton fiber genes, encoding cysteine proteinase, vacuolar H+-pyro- phosphatase, vacuolar H+-ATPase, catalytic subunit, arabinogalactan protein, putative receptor protein kinase PERK1, GIA/RGA-like gibberellin response modulator and cellulose synthase. Some other transcripts may represent new gene fragments in cotton fiber development. Surprisingly, 46 of the 75 transcripts were mapped to a single linkage group. The transcriptome groups and the sequenced TDFs could serve as important resources in the functional genomic research of cotton fiber development.
