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An innovative approach for measuring wind fields in urban building clusters using Unmanned Aerial Vehicles (UAVs) is presented. This method captures the distribution of wind fields within clusters. The results indicate that building architecture has a significant influence on wind flow characteristics at 15 m and 25 m height levels. Particularly, areas adjacent to the buildings and the wake section exhibit notable variations in wind speed and turbulence intensity compared to the incoming flow. The regions most affected include the areas flanking the buildings on either side and the intermediate section of the wake. The flow separation and convergence of incoming wind from the windward sides of the buildings notably amplify the wind load, resulting in a significant shift in wind speed and turbulence intensity within pedestrian pathways. The use of UAVs for wind measurements enables a flexible and efficient assessment of urban wind fields. These findings pave the way for further research into wind field measurements in urban architecture and a better understanding of the interference effects of buildings.

We propose and experimentally demonstrate an approach for generating a wideband optical frequency comb (OFC) featuring multiple comb lines and wavelength tunability based on a gain-switched weak-resonant-cavity Fabry–Perot laser diode (WRC-FPLD) under multi-wavelength optical injection. The longitudinal mode interval of the utilized WRC-FPLD is about 0.28 nm (35.0 GHz), and its relaxation oscillation frequency is about 2.0 GHz at 1.15 times the threshold current. Under current modulation with a power of 20.00 dBm and a frequency of 2.0 GHz, the WRC-FPLD is driven into the gain-switched state. By further introducing multi-wavelength injection light (MWIL) containing four power equalization comb lines with an interval of 0.56 nm, a wideband OFC featuring multiple comb lines and wavelength tenability can be obtained. The experimental results demonstrate that by gradually increasing the injection's optical power, the number of produced OFC lines initially increases and then decreases. By meticulously adjusting the wavelengths of the MWIL and carefully selecting the matched injection power, the broadband OFC can be tuned across an extensive spectral range. Under optimized operation parameters, an OFC with 147 lines, and a bandwidth of approximately 292 GHz within a 10 dB amplitude, variation is achieved. In this case, the measured single-sideband phase noise at the fundamental frequency is about −115 dBc/Hz @ 10 kHz, indicating that the comb lines possess good stability and strong coherence. [ABSTRACT FROM AUTHOR]

According to the conserved sequences flanking the 3' end of the 16S and the 5' end of the 23S rDNAs, PCR primers were designed, and the 16S-23S rDNA intergenic spacers (IGSs) of two strains of Vibrio vulnificus were amplified by PCR and cloned into pGEM-T vector. Different clones were selected to be sequenced and the sequences were analyzed with BLAST and the software DNAstar. Analyses of the IGS sequences suggested that the strain ZSU006 contains five types of polymorphic 16S-23S rDNA intergenic spacers, namely, IGSGLAV, IGSGLV, IGSIA, IGSG and IGSA; while the strain CG021 has the same types of IGSs except lacking IGSA. Among these five IGS types, IGSGLAV is the biggest type, including the gene cluster of tRNAGlu-tRNALys-tRNAAla-tRNAVal; IGSGLV includes that of tRNAGlu-tRNALys-tRNAVal; IGSAG, tRNAAla-tRNAGlu; IGSIA, tRNAIle-tRNAAla; IGSG, tRNAGlu and IGSA, tRNAAla. Intraspecies multiple alignment of all the IGS sequences of these two strains with those of V. vulnificus ATCC27562 available at GenBank revealed several highly conserved sequence blocks in the non- coding regions flanking the tRNA genes within all of strains, most notably the first 40 and last 200 nucleotides, which can be targeted to design species-specific PCR primers or detection probes. The structural variations of the 16S-23S rDNA intergenic spacers lay a foundation for developing diagnostic methods for V. vulnificus.