The phase component, the grain size and the magnetic properties of rapidly quenching Nd 9(FeCoZrAl) 85 B 6 amorphous alloy at different heat treatment were investigated. The heat treatment process influences obv...The phase component, the grain size and the magnetic properties of rapidly quenching Nd 9(FeCoZrAl) 85 B 6 amorphous alloy at different heat treatment were investigated. The heat treatment process influences obviously the crystallizing of Nd 2Fe 14 B and α Fe phase, the grain size and the magnetic properties of the alloy. When the heat treatment temperature is lower, the crystallizing of amorphous phase is not sufficient, the grains grow unhomogeneously, so the grain size of Nd 2Fe 14 B phase is much larger. When the heat treatment temperature is much higher, although the amorphous phase is fully crystallized, the grains grow quickly and its size is much larger, too. When the amorphous alloy is heat treated at a proper temperature at 685 ℃ and 30 min, the amorphous phase is fully crystallized and the growth of Nd 2Fe 14 B grains is not remarkable. Thus the grain size is very small, and the magnetic coupling effect reaches a maximum value between the Nd 2Fe 14 B grains and between the Nd 2Fe 14 B grain and α Fe grain, so the alloy possesses good magnetic properties, and the magnetic properties of epoxy resin bonded magnet from the alloy are B r=655 mT, j H c =639 2 kA·m -1 , b H c =381 6 kA·m -1 , ( BH ) m=65 68 kJ·m -3 .展开更多
Based on the comprehensive analysis of hydrogen storageexperimental results for Zr-Ni amor- phous alloy, the quantitativerelationship of PCT curve was established, the calculated results areconsistent with experimenta...Based on the comprehensive analysis of hydrogen storageexperimental results for Zr-Ni amor- phous alloy, the quantitativerelationship of PCT curve was established, the calculated results areconsistent with experimental ones.展开更多
The ZrTiCuNiBe alloy is melt and solidified by Bridgman unidirectional solidification on two gravity field orientations (the gravity field orientation is parallel and opposite to solidification direction). Effects of ...The ZrTiCuNiBe alloy is melt and solidified by Bridgman unidirectional solidification on two gravity field orientations (the gravity field orientation is parallel and opposite to solidification direction). Effects of gravity on morphology and microstructure are investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). When gravity field orientation is parallel to solidificationdirection, less needle-like primary phase is embedded in a matrix eutectic; when gravity field orientation is opposite to solidification direction, a large amount of coarser needle-like primary phases were observed.展开更多
Candidatus Accumulibacter,a prominent polyphosphate-accumulating organism(PAO)in wastewater treatment,plays a crucial role in enhanced biological phosphorus removal(EBPR).The genetic underpinnings of its polyphosphate...Candidatus Accumulibacter,a prominent polyphosphate-accumulating organism(PAO)in wastewater treatment,plays a crucial role in enhanced biological phosphorus removal(EBPR).The genetic underpinnings of its polyphosphate accumulation capabilities,however,remain largely unknown.Here,we conducted a comprehensive genomic analysis of Ca.Accumulibacter-PAOs and their relatives within the Rhodocyclaceae family,identifying 124 core genes acquired via horizontal gene transfer(HGT)at its least common ancestor.Metatranscriptomic analysis of an enrichment culture of Ca.Accumulibacter revealed active transcription of 44 of these genes during an EBPR cycle,notably including the polyphosphate kinase 2(PPK2)gene instead of the commonly recognized polyphosphate kinase 1(PPK1)gene.Intriguingly,the phosphate regulon(Pho)genes showed minimal transcriptions,pointing to a distinctive fact of Pho dysregulation,where PhoU,the phosphate signaling complex protein,was not regulating the high-affinity phosphate transport(Pst)system,resulting in continuous phosphate uptake.To prevent phosphate toxicity,Ca.Accumulibacter utilized the laterally acquired PPK2 to condense phosphate into polyphosphate,resulting in the polyphosphate-accumulating feature.This study provides novel insights into the evolutionary emergence of the polyphosphate-accumulating trait in Ca.Accumulibacter,offering potential advancements in understanding the PAO phenotype in the EBPR process.展开更多
文摘The phase component, the grain size and the magnetic properties of rapidly quenching Nd 9(FeCoZrAl) 85 B 6 amorphous alloy at different heat treatment were investigated. The heat treatment process influences obviously the crystallizing of Nd 2Fe 14 B and α Fe phase, the grain size and the magnetic properties of the alloy. When the heat treatment temperature is lower, the crystallizing of amorphous phase is not sufficient, the grains grow unhomogeneously, so the grain size of Nd 2Fe 14 B phase is much larger. When the heat treatment temperature is much higher, although the amorphous phase is fully crystallized, the grains grow quickly and its size is much larger, too. When the amorphous alloy is heat treated at a proper temperature at 685 ℃ and 30 min, the amorphous phase is fully crystallized and the growth of Nd 2Fe 14 B grains is not remarkable. Thus the grain size is very small, and the magnetic coupling effect reaches a maximum value between the Nd 2Fe 14 B grains and between the Nd 2Fe 14 B grain and α Fe grain, so the alloy possesses good magnetic properties, and the magnetic properties of epoxy resin bonded magnet from the alloy are B r=655 mT, j H c =639 2 kA·m -1 , b H c =381 6 kA·m -1 , ( BH ) m=65 68 kJ·m -3 .
文摘Based on the comprehensive analysis of hydrogen storageexperimental results for Zr-Ni amor- phous alloy, the quantitativerelationship of PCT curve was established, the calculated results areconsistent with experimental ones.
基金the National NaturalScience Foundation of China (Grant No. 59889102) and the Chinese National Microgravity Laboratory (PAN-YU-95-34).
文摘The ZrTiCuNiBe alloy is melt and solidified by Bridgman unidirectional solidification on two gravity field orientations (the gravity field orientation is parallel and opposite to solidification direction). Effects of gravity on morphology and microstructure are investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). When gravity field orientation is parallel to solidificationdirection, less needle-like primary phase is embedded in a matrix eutectic; when gravity field orientation is opposite to solidification direction, a large amount of coarser needle-like primary phases were observed.
基金supported by the National Natural Science Foundation of China(52270035 and 51808297)the Natural Science Foundation of Guangdong Province(2021A1515010494)+1 种基金the Guangzhou Key Research and Development Program(2023B03J1334)the Pearl River Talent Recruitment Program(2019QN01L125).
文摘Candidatus Accumulibacter,a prominent polyphosphate-accumulating organism(PAO)in wastewater treatment,plays a crucial role in enhanced biological phosphorus removal(EBPR).The genetic underpinnings of its polyphosphate accumulation capabilities,however,remain largely unknown.Here,we conducted a comprehensive genomic analysis of Ca.Accumulibacter-PAOs and their relatives within the Rhodocyclaceae family,identifying 124 core genes acquired via horizontal gene transfer(HGT)at its least common ancestor.Metatranscriptomic analysis of an enrichment culture of Ca.Accumulibacter revealed active transcription of 44 of these genes during an EBPR cycle,notably including the polyphosphate kinase 2(PPK2)gene instead of the commonly recognized polyphosphate kinase 1(PPK1)gene.Intriguingly,the phosphate regulon(Pho)genes showed minimal transcriptions,pointing to a distinctive fact of Pho dysregulation,where PhoU,the phosphate signaling complex protein,was not regulating the high-affinity phosphate transport(Pst)system,resulting in continuous phosphate uptake.To prevent phosphate toxicity,Ca.Accumulibacter utilized the laterally acquired PPK2 to condense phosphate into polyphosphate,resulting in the polyphosphate-accumulating feature.This study provides novel insights into the evolutionary emergence of the polyphosphate-accumulating trait in Ca.Accumulibacter,offering potential advancements in understanding the PAO phenotype in the EBPR process.
