Friction stir processing(FSP) has emerged as a transformative solid-state technique for enhancing the mechanical performance and microstructural integrity of metallic materials,particularly in the context of additive ...Friction stir processing(FSP) has emerged as a transformative solid-state technique for enhancing the mechanical performance and microstructural integrity of metallic materials,particularly in the context of additive manufacturing(AM).This study demonstrates the effectiveness of FSP as a post-processing strategy for two distinct AM systems:wire arc additive manufacturing(WAAM) of low-carbon steel and selective laser melting(SLM) of Ti6Al4V alloy.In the case of WAAM fabricated steel,FSP significantly refined the coarse dendritic microstructure into ultrafine equiaxed grains,resulting in a 21 %-24 % increase in hardness and enhanced tensile properties at the overlapping regions.Similarly,for SLM fabricated Ti6Al4V,FSP eliminated the columnar prior-β grains and residual porosity,yielding a homogenous α+β structure with improved strengthductility balance and reduced anisotropy.These improvements were attributed to the dynamic recrystallization,conversion of low-angle to high-angle grain boundaries,and homogenization of phase constituents induced by FSP.Despite challenges such as tool wear and fixturing complexity,the study confirms that FSP can reliably bridge the performance gap in AM components by healing solidification defects,mitigating anisotropy,and tailoring the local microstructure.The findings position FSP as a versatile and scalable post-processing technique,crucial for advancing high-performance,application-ready components in aerospace,biomedical,and structural applications.展开更多
Objective To establish and evaluate a real-time PCR assay to detect Mycoplasma pneumoniae （M.pneumoniae） in clinical specimens. Methods By analysing the whole pl gene sequence of 60 M.pneurnoniae clinical isolates i...Objective To establish and evaluate a real-time PCR assay to detect Mycoplasma pneumoniae （M.pneumoniae） in clinical specimens. Methods By analysing the whole pl gene sequence of 60 M.pneurnoniae clinical isolates in Beijing of China, an optimized real-time PCR assay （MpP1） using pl gene conserved region was designed. The specificity and sensitivity of this assay were evaluated and compared with other two reported assays （RepMpl and Mp181） using 40 positive and 100 negative clinical specimens. Results The detection limit of the new assay was 8.1 fg （about 1-3CFU） M.pneumoniae DNA. The sensitivity of MpP1, RepMpl, and Mp181 assays appeared to be 100%, 100%, and 85%, respectively. Conclusion MpP1 assay is suitable for the detection of M.pneumoniae in Chinese clinical specimens.展开更多
field attraction test of (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (= 7R,8S-epo-2me-17ene-18Hy), a trace component of the sex pheromone gland of the Asian gypsy moth,(Lymantria dispar), traps that were baited with...field attraction test of (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (= 7R,8S-epo-2me-17ene-18Hy), a trace component of the sex pheromone gland of the Asian gypsy moth,(Lymantria dispar), traps that were baited with the trace component attracted more L. dispar than traps baited with (7S,8R)-cis-7,8-epoxy-2-methyloctadec-17-ene (= 7S,8R-epo-2me-17ene-18Hy) and unbaited traps. However, traps baited with 7R,8S-epo-2me-17ene-18Hy were less attractive than traps baited with (+)-disparlure [=(7R,8S)-cis-7,8-epoxy-2-methyloctadecane], the sex pheromone of L. dispar. Combination tests with (?)-disparlure, 7R,8S-epo-2me-17ene-18Hy, and 7S,8R-epo-2me- 17ene-18Hy revealed that 7R,8S-epo-2me-17ene-18Hy acted synergistically with (?)-disparlure.展开更多
基金funded by the National Natural Science Foundation of China(Grant No.52322508)the R&D Program of Beijing Municipal Education Commission(Grant No.KZ20231000519).
文摘Friction stir processing(FSP) has emerged as a transformative solid-state technique for enhancing the mechanical performance and microstructural integrity of metallic materials,particularly in the context of additive manufacturing(AM).This study demonstrates the effectiveness of FSP as a post-processing strategy for two distinct AM systems:wire arc additive manufacturing(WAAM) of low-carbon steel and selective laser melting(SLM) of Ti6Al4V alloy.In the case of WAAM fabricated steel,FSP significantly refined the coarse dendritic microstructure into ultrafine equiaxed grains,resulting in a 21 %-24 % increase in hardness and enhanced tensile properties at the overlapping regions.Similarly,for SLM fabricated Ti6Al4V,FSP eliminated the columnar prior-β grains and residual porosity,yielding a homogenous α+β structure with improved strengthductility balance and reduced anisotropy.These improvements were attributed to the dynamic recrystallization,conversion of low-angle to high-angle grain boundaries,and homogenization of phase constituents induced by FSP.Despite challenges such as tool wear and fixturing complexity,the study confirms that FSP can reliably bridge the performance gap in AM components by healing solidification defects,mitigating anisotropy,and tailoring the local microstructure.The findings position FSP as a versatile and scalable post-processing technique,crucial for advancing high-performance,application-ready components in aerospace,biomedical,and structural applications.
基金supported by the National Key Program for Infectious Diseases of China,No.2008ZX10004-002
文摘Objective To establish and evaluate a real-time PCR assay to detect Mycoplasma pneumoniae （M.pneumoniae） in clinical specimens. Methods By analysing the whole pl gene sequence of 60 M.pneurnoniae clinical isolates in Beijing of China, an optimized real-time PCR assay （MpP1） using pl gene conserved region was designed. The specificity and sensitivity of this assay were evaluated and compared with other two reported assays （RepMpl and Mp181） using 40 positive and 100 negative clinical specimens. Results The detection limit of the new assay was 8.1 fg （about 1-3CFU） M.pneumoniae DNA. The sensitivity of MpP1, RepMpl, and Mp181 assays appeared to be 100%, 100%, and 85%, respectively. Conclusion MpP1 assay is suitable for the detection of M.pneumoniae in Chinese clinical specimens.
基金support of the "Cooperative Research Program for Agriculture Science and Technology Development(Project No.PJ01175601)" Rural Development Administration,Republic of Korea
文摘field attraction test of (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (= 7R,8S-epo-2me-17ene-18Hy), a trace component of the sex pheromone gland of the Asian gypsy moth,(Lymantria dispar), traps that were baited with the trace component attracted more L. dispar than traps baited with (7S,8R)-cis-7,8-epoxy-2-methyloctadec-17-ene (= 7S,8R-epo-2me-17ene-18Hy) and unbaited traps. However, traps baited with 7R,8S-epo-2me-17ene-18Hy were less attractive than traps baited with (+)-disparlure [=(7R,8S)-cis-7,8-epoxy-2-methyloctadecane], the sex pheromone of L. dispar. Combination tests with (?)-disparlure, 7R,8S-epo-2me-17ene-18Hy, and 7S,8R-epo-2me- 17ene-18Hy revealed that 7R,8S-epo-2me-17ene-18Hy acted synergistically with (?)-disparlure.
