Selective laser melting(SLM)or Laser-based powder bed fusion(LBPF)is gaining much attention for the fabrication of novel materials with complex shapes,improved functionalities,and properties.An attempt has been made t...Selective laser melting(SLM)or Laser-based powder bed fusion(LBPF)is gaining much attention for the fabrication of novel materials with complex shapes,improved functionalities,and properties.An attempt has been made to fabricate hard and brittle silicon via SLM in the absence of any cracks.Two different powder batches were used,where one of the powder batches has 0.3wt%Fe and the other batch with 0.02wt%Fe.The parameter optimization process shows that the SLM Si samples were successfully fabricated from the powders with the minor addition of Fe.The deliberate addition of Fe facilitates heterogeneous nucleation of Si and aids in absorbing the laser energy beam more efficiently.SLM Si samples with 98.5%theoretical density were fabricated with a hardness of around 10.65±40 GPa.The experimental results show that SLM can successfully fabricate Si without cracks and with near theoretical density(of 99%)and complex shapes,which opens their use in wider industrial applications.展开更多
暗褐网柄牛肝菌(Phlebopus portentosus)是第一个栽培成功的牛肝菌目(Boletales)真菌,一般采用覆土栽培模式,覆土微生物对子实体的发育具有重要作用,目前的研究主要集中在覆土微生物上,但缺少对子实体内生菌的研究。为揭开暗褐网柄牛肝...暗褐网柄牛肝菌(Phlebopus portentosus)是第一个栽培成功的牛肝菌目(Boletales)真菌,一般采用覆土栽培模式,覆土微生物对子实体的发育具有重要作用,目前的研究主要集中在覆土微生物上,但缺少对子实体内生菌的研究。为揭开暗褐网柄牛肝菌子实体内生菌的组成,本研究基于Illumina MiSeq平台,利用16S rRNA V3~V4区高通量测序进行细菌群落结构分析。结果表明子实体(fruiting body,FB)内部存在很高丰度的细菌,主要以变形菌门(Proteobacteria)为主,在属水平上以贪铜菌属(Cupriavidus)(64.98%)、不动杆菌属(Acinetobacter)(7.62%)、苍白杆菌属(Ochrobactrum)(6.02%)为主。与覆土(casing soil,CS)基质固有的细菌种群进行比较,VENN分析显示子实体内有468个OTUs为独有,占总序列的26.65%,分类上隶属于贪铜菌属、不动杆菌属和Delftia。FB和CS差异性分析以及Lefse标志性微生物分析均显示贪铜菌属、苍白杆菌属、不动杆菌属、嗜糖假单胞菌属(Pelomonas)等为FB特异性、标志性类群。利用Picrust(Phylogenetic investigation of communities by reconstruction of unobserved states)进行Kyoto Encyclopedia of Genes and Genomes(KEGG)通路预测发现,子实体内生菌群的主要代谢途径为膜传输、氨基酸代谢、碳水化合物代谢、外源生物降解与代谢,与覆土菌群有20个代谢通路的差异,并且外源生物降解与代谢、信号转导、其他氨基酸代谢、脂质代谢、细胞过程和信号5个通路的比例要高于覆土,微生物类群的差异可能是导致产生这些功能差异的原因。展开更多
A causal relationship has been reported between the average population salt(sodium chloride)intake and the increased risk of stroke and cardiovascular and cerebrovascular diseases in some epidemiological and clinical ...A causal relationship has been reported between the average population salt(sodium chloride)intake and the increased risk of stroke and cardiovascular and cerebrovascular diseases in some epidemiological and clinical studies.The World Health Organization has recommended that a sodium intake of<2 g/day is preventive against cardiovascular disease,although the current intake is in excess in most countries.展开更多
基金by the Shenzhen Institute of Information Technology School-Enterprise Collaborative Innovation(No.SZIIT2021KJ057)the High-end Foreign Experts Recruitment Program(No.G2021163004L)+2 种基金the Natural Science Foundation of Guangdong Province(2020A1515011242)the Guangdong International Science and Technology Cooperation Program((No.2021A0505050002)the European Regional Development Grant(No.ASTRA6-6)。
文摘Selective laser melting(SLM)or Laser-based powder bed fusion(LBPF)is gaining much attention for the fabrication of novel materials with complex shapes,improved functionalities,and properties.An attempt has been made to fabricate hard and brittle silicon via SLM in the absence of any cracks.Two different powder batches were used,where one of the powder batches has 0.3wt%Fe and the other batch with 0.02wt%Fe.The parameter optimization process shows that the SLM Si samples were successfully fabricated from the powders with the minor addition of Fe.The deliberate addition of Fe facilitates heterogeneous nucleation of Si and aids in absorbing the laser energy beam more efficiently.SLM Si samples with 98.5%theoretical density were fabricated with a hardness of around 10.65±40 GPa.The experimental results show that SLM can successfully fabricate Si without cracks and with near theoretical density(of 99%)and complex shapes,which opens their use in wider industrial applications.
文摘暗褐网柄牛肝菌(Phlebopus portentosus)是第一个栽培成功的牛肝菌目(Boletales)真菌,一般采用覆土栽培模式,覆土微生物对子实体的发育具有重要作用,目前的研究主要集中在覆土微生物上,但缺少对子实体内生菌的研究。为揭开暗褐网柄牛肝菌子实体内生菌的组成,本研究基于Illumina MiSeq平台,利用16S rRNA V3~V4区高通量测序进行细菌群落结构分析。结果表明子实体(fruiting body,FB)内部存在很高丰度的细菌,主要以变形菌门(Proteobacteria)为主,在属水平上以贪铜菌属(Cupriavidus)(64.98%)、不动杆菌属(Acinetobacter)(7.62%)、苍白杆菌属(Ochrobactrum)(6.02%)为主。与覆土(casing soil,CS)基质固有的细菌种群进行比较,VENN分析显示子实体内有468个OTUs为独有,占总序列的26.65%,分类上隶属于贪铜菌属、不动杆菌属和Delftia。FB和CS差异性分析以及Lefse标志性微生物分析均显示贪铜菌属、苍白杆菌属、不动杆菌属、嗜糖假单胞菌属(Pelomonas)等为FB特异性、标志性类群。利用Picrust(Phylogenetic investigation of communities by reconstruction of unobserved states)进行Kyoto Encyclopedia of Genes and Genomes(KEGG)通路预测发现,子实体内生菌群的主要代谢途径为膜传输、氨基酸代谢、碳水化合物代谢、外源生物降解与代谢,与覆土菌群有20个代谢通路的差异,并且外源生物降解与代谢、信号转导、其他氨基酸代谢、脂质代谢、细胞过程和信号5个通路的比例要高于覆土,微生物类群的差异可能是导致产生这些功能差异的原因。
基金supported by the National Natural Science Foundation of China[22006006]the Fundamental Research Funds for the Central Universities[No.3132022158]。
文摘A causal relationship has been reported between the average population salt(sodium chloride)intake and the increased risk of stroke and cardiovascular and cerebrovascular diseases in some epidemiological and clinical studies.The World Health Organization has recommended that a sodium intake of<2 g/day is preventive against cardiovascular disease,although the current intake is in excess in most countries.
