Crystal growth, spectroscopic characteristics, and Judd–Ofelt analysis of Dy:Lu_2O_3 for yellow laser

Dy：Lu2O3 was grown by the float-zone （Fz） method. According to the absorption spectrum, the Judd-Ofelt （JO） parameters Ω2, Ω4, and Ω6 were calculated to be 4.86 × 10-20 cm2, 2.02 × 10-20 cm2, and 1.76 ×10-20 cm2, respectively. The emission cross-section at 574 nm corresponding to the 4F9/2 →6H13/2 transition was calculated to be 0.53 ×10 20 cm2. The yellow （4F9/2 →6H13/2 transition） to blue （4F9/2 →6H15/2 transition） intensity ratio ranges up to 12.9. The fluorescence lifetime of the 4F9/2 energy level was measured to be 112.1 μs. These results reveal that Dy：Lu2O3 is a promising material for use in yellow lasers.

Crystal growth and spectral properties of Tb：Lu2O3

The crystal growth,x-ray diffraction pattern,absorption spectrum,emission spectrum,and fluorescence lifetime of a Tb：Lu2O3 single crystal were studied.Excited at 483 nm,the peak absorption cross-section was calculated to be 3.5×10（-22）cm2,and the full width at half maximum was found to be 2.85 nm.The Judd-Ofelt（J-O）intensity parameters 2,4,and 6 were computed to be 3.79×10（-20）cm2,1.30×10（-20）cm2,and 1.08×10（-20）cm2,with a spectroscopic quality factor 4/6 being 1.20.The emission cross-sections of green emission around 543 nm and yellow emission around 584 nm were calculated to be 9.43×10（-22）cm2 and 1.32×10（-22）cm2,respectively.The fluorescence lifetimeτexp of -5D4 was fitted to be 1.13 ms.The data suggest that the Tb：Lu2O3 crystal could be a potential candidate for green and yellow laser operation.

Odorant-binding protein 19 in Monochamus alternatus involved in the recognition of a volatile strongly emitted from ovipositing host pines

Monochamus alternatus is the primary carrier of pine wood nematodes,which pose a serious threat to Pinus spp.in many countries.Newly emerging M.alternatus adults feed on heathy host pines,while matured adults transfer to stressed host pines for mating and oviposition.Several odorant-binding proteins(OBPs)of M.alternatus have been proved to aid in the complex process of host location.To clarify the corresponding relations between OBPs and pine volatiles,more OBPs need to be studied.In this research,MaltOBP19 showed a specific expression in the antennae and mouthparts of M.alternatus,and it was marked in 4 types of antenna sensilla by immunolocalization.Fluorescence binding assays demonstrated the high binding affinity of MaltOBP19 with camphene and myrcene in vitro.In Y-tube olfactory experiments,M.alternatus adults were attracted by camphene and RNAi of OBP19 via microinjection significantly decreased their attraction index.Myrcene induced phobotaxis,but RNAi had no significant effect on this behavior.Further,we found that ingesting dsOBP19 produced by a bacteria-expressed system with a newly constructed vector could lead to the knockdown of MaltOBP19.These results suggest that MaltOBP19 may play a role in the process of host conversion via the recognition of camphene,which has been identified to be strongly released in stressed host pines.In addition,it is proved that knockdown of OBP can be achieved by oral administration of bacteria-expressed double-stranded RNA in M.alternatus adults,providing a new perspective in the control of M.alternatus.

High power and energy generation in a Nd:YAG single-crystal fiber laser at 1834 nm

We report on a diode-end-pumped high-power and high-energy Nd:YAG single-crystal fiber laser at 1834 nm.Two 808 nm diodes injecting about 58 W pump power into the Nd:YAG fiber have generated 3.28 W continuouswave and 1.66 W Cr:ZnSe-based passively Q-switched lasers. Slope efficiencies with respect to pump powers are8.7% for the continuous-wave laser and 4.9% for the Q-switched laser. The extracted maximum pulse energy is about 266.9 μJ, and the corresponding maximum pulse peak power is 2.54 kW. These performances greatly surpass previous results regarding this specific laser emission because the laser gain medium in the form of fiber can significantly mitigate thermally induced power saturation thanks to its significantly reduced thermal lensing effect. Single-crystal fiber lasers show great potential for high average power, pulse energy, and peak power.

Transcriptomic response of Pinus massoniana to infection stress from the pine wood nematode Bursaphelenchus xylophilus

The pinewood nematode(PWN)Bursaphelenchus xylophilus is a forestry quarantine pest and causes an extremely dangerous forest disease that is spreading worldwide.Due to the complex pathogenic factors of pine wood nematode disease,the pathogenesis is still unknown.B.xylophilus ultimately invades a host and causes death.However,little is known about the defence-regulating process of host pine after infection by B.xylophilus at the molecular level.Therefore,we wanted to understand how Pinus massoniana regulates its response to invasion by B.xylophilus.P.massoniana were artificially inoculated with B.xylophilus solution,while those without B.xylophilus solution were used as controls.P.massoniana inoculated with B.xylophilus solution for 0 h,6 h,24 h,and 120 h was subjected to highthroughput sequencing to obtain transcriptome data.At various time points(0 h,6 h,24 h,120 h),gene transcription was measured in P.massoniana inoculated with PWN.At different time points,P.massoniana gene transcription differed significantly,with a response to early invasion by PWN.According to Gene Ontology(GO)classification and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis,P.massoniana response to PWN invasion involves a wide range of genes,including plant hormone signal transformation,flavonoid biosynthesis,amino sugar and nucleoside sugar metabolism,and MAPK signalling pathways.Among them,inoculation for 120 hours had the greatest impact on differential genes.Subsequently,weighted gene coexpression network analysis(WGCNA)was used to analyse transcriptional regulation of P.massoniana after PWN infection.The results showed that the core gene module of P.massoniana responding to PWN was“MEmagenta”,enriched in oxidative phosphorylation,amino sugar and nucleotide sugar metabolism,and the MAPK signalling pathway.MYB family transcription factors with the highest number of changes between infected and healthy pine trees accounted for 20.4% of the total differentially expressed transcription factors.To conclude,this study contributes to our understanding of the molecular mechanism of initial PWN infection of P.massoniana.Moreover,it provides some important background information on PWN pathogenic mechanisms.