The effects of rare earth Ce on the microstructure and mechanical properties of impure copper containing Pb were investigated using OM,SEM,EPMA,TEM and tensile testing.TEM and EDS analysis reveal that spherical CePb3 ...The effects of rare earth Ce on the microstructure and mechanical properties of impure copper containing Pb were investigated using OM,SEM,EPMA,TEM and tensile testing.TEM and EDS analysis reveal that spherical CePb3 particles form after Ce addition.CePb3 particles,with average size of^3.6μm,homogenously distribute in the Cu matrix.Due to small lattice misfit(~4.62%)with Cu matrix,CePb3 particles can act as effective nucleation sites beneficial to the grain refinement.Pb at grain boundaries seriously deteriorates the mechanical properties of Cu.The tensile strength and the elongation of Cu-0.1 Pb are decreased by 43.1%and 56.7%compared with those of pure copper,respectively.Ce can purify grain boundaries,cause the precipitation of CePb3 particles and refine grain sizes,which contribute to significant improvement of the mechanical properties of Cu.Compared with Cu-0.1Pb,the tensile strength(179 MPa)and the elongation(38.5%)of Cu-0.1Pb-0.3Ce are increased by 117.6%and 151.6%,respectively.展开更多
This study was carried out to investigate the biogenic amines(BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish ...This study was carried out to investigate the biogenic amines(BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish were gathered from retail and wholesale markets and manufacturers, which had been produced in various regions in China. Cadaverine(CAD) and putrescine(PUT) were quantitatively the most common biogenic amines. About 14% of the samples exceeded the histamine content standards established by the FDA and/or EU. The highest histamine content was found in Silver pomfret(Pampus argenteus)(347.79 mg kg^(-1)). Five of forty three samples exceeded the acceptable content of TYR(100 mg kg^(-1)), and 23.26% of dried-salted fish contained high contents of biogenic amines(above 600 mg kg^(-1)). In addition, species, regions, pickling processes and drying methods made the physicochemical property, microorganisms and biogenic amines in dry salted fish to be different to some extents. The total plate count(TPC) was much higher than that of total halophilic bacteria in all samples. The biogenic amines, physicochemical property and microbiological counts exhibited large variations among samples. Furthermore, no significant correlation between biogenic amines and physicochemical property and TPC was observed. This study indicated that dry salted fish may still present healthy risk for BAs, depending on the processing methods, storage conditions among others.展开更多
As high-grade magnesite and brucite resources(hereinafter referred to as magnesium-containing minerals)are decreasing annually,developing flotation separation technologies capable of efficiently and economically extra...As high-grade magnesite and brucite resources(hereinafter referred to as magnesium-containing minerals)are decreasing annually,developing flotation separation technologies capable of efficiently and economically extracting magnesium resources from low-grade magnesium-containing minerals is necessary.Although efficient flotation separation technologies for magnesium-containing minerals are well researched,related concepts are not yet clarified.Moreover,the industrial development of magnesium-containing mineral flotation technologies is limited by their low separation efficiency and environmental problems.This limitation has inhibited the full utilization of low-grade magnesium-containing minerals.This study comprehensively discusses the research progress of flotation separation technologies for magnesium-containing minerals,focusing on the crystal chemical and surface characteristics of magnesium-containing minerals and their gangue minerals,effect of inevitable ions on mineral flotation behavior,interaction effects of minerals,and research advancement of flotation reagents.The study aims to clarify the future development direction of the flotation separation of magnesium-containing minerals and provide theoretical support and technical references for an efficient separation.展开更多
Magnesium-doped calcium silicate(CS)bioceramic scaffolds have unique advantages in mandibular defect repair;however,they lack antibacterial properties to cope with the complex oral microbiome.Herein,for the first time...Magnesium-doped calcium silicate(CS)bioceramic scaffolds have unique advantages in mandibular defect repair;however,they lack antibacterial properties to cope with the complex oral microbiome.Herein,for the first time,the CS scaffold was functionally modified with a novel copper-containing polydopamine(PDA(Cu^(2+)))rapid deposition method,to construct internally modified(*P),externally modified(@PDA),and dually modified(*P@PDA)scaffolds.The morphology,degradation behavior,and mechanical properties of the obtained scaffolds were evaluated in vitro.The results showed that the CS*P@PDA had a unique micro-/nano-structural surface and appreciable mechanical resistance.During the prolonged immersion stage,the release of copper ions from the CS*P@PDA scaffolds was rapid in the early stage and exhibited long-term sustained release.The in vitro evaluation revealed that the release behavior of copper ions ascribed an excellent antibacterial effect to the CS*P@PDA,while the scaffolds retained good cytocompatibility with improved osteogenesis and angiogenesis effects.Finally,the PDA(Cu^(2+))-modified scaffolds showed effective early bone regeneration in a critical-size rabbit mandibular defect model.Overall,it was indicated that considerable antibacterial property along with the enhancement of alveolar bone regeneration can be imparted to the scaffold by the two-step PDA(Cu^(2+))modification,and the convenience and wide applicability of this technique make it a promising strategy to avoid bacterial infections on implants.展开更多
基金Projects(ZR2018MEE005,ZR2018MEE016)supported by the Natural Science Foundation of Shandong Province,ChinaProject(J18KA059)supported by the Higher Educational Science and Technology Program of Shandong Province,ChinaProject(HJ16B01)supported by the Doctoral Fund of Yantai University,China。
文摘The effects of rare earth Ce on the microstructure and mechanical properties of impure copper containing Pb were investigated using OM,SEM,EPMA,TEM and tensile testing.TEM and EDS analysis reveal that spherical CePb3 particles form after Ce addition.CePb3 particles,with average size of^3.6μm,homogenously distribute in the Cu matrix.Due to small lattice misfit(~4.62%)with Cu matrix,CePb3 particles can act as effective nucleation sites beneficial to the grain refinement.Pb at grain boundaries seriously deteriorates the mechanical properties of Cu.The tensile strength and the elongation of Cu-0.1 Pb are decreased by 43.1%and 56.7%compared with those of pure copper,respectively.Ce can purify grain boundaries,cause the precipitation of CePb3 particles and refine grain sizes,which contribute to significant improvement of the mechanical properties of Cu.Compared with Cu-0.1Pb,the tensile strength(179 MPa)and the elongation(38.5%)of Cu-0.1Pb-0.3Ce are increased by 117.6%and 151.6%,respectively.
基金financially supported by the National Natural Science Foundation of China (No.31371800)the National Science-Technology Support Plan Project (2012BAD28B05)
文摘This study was carried out to investigate the biogenic amines(BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish were gathered from retail and wholesale markets and manufacturers, which had been produced in various regions in China. Cadaverine(CAD) and putrescine(PUT) were quantitatively the most common biogenic amines. About 14% of the samples exceeded the histamine content standards established by the FDA and/or EU. The highest histamine content was found in Silver pomfret(Pampus argenteus)(347.79 mg kg^(-1)). Five of forty three samples exceeded the acceptable content of TYR(100 mg kg^(-1)), and 23.26% of dried-salted fish contained high contents of biogenic amines(above 600 mg kg^(-1)). In addition, species, regions, pickling processes and drying methods made the physicochemical property, microorganisms and biogenic amines in dry salted fish to be different to some extents. The total plate count(TPC) was much higher than that of total halophilic bacteria in all samples. The biogenic amines, physicochemical property and microbiological counts exhibited large variations among samples. Furthermore, no significant correlation between biogenic amines and physicochemical property and TPC was observed. This study indicated that dry salted fish may still present healthy risk for BAs, depending on the processing methods, storage conditions among others.
基金financially supported by the Open Foundation of State Key Laboratory of Mineral Processing (No.BGRIMM-KJSKL-2024-07)the Open Project of the Key Laboratory of Solid Waste Treatment and Resource Utilization of the Ministry of Education,China (No.23kfgk02)。
文摘As high-grade magnesite and brucite resources(hereinafter referred to as magnesium-containing minerals)are decreasing annually,developing flotation separation technologies capable of efficiently and economically extracting magnesium resources from low-grade magnesium-containing minerals is necessary.Although efficient flotation separation technologies for magnesium-containing minerals are well researched,related concepts are not yet clarified.Moreover,the industrial development of magnesium-containing mineral flotation technologies is limited by their low separation efficiency and environmental problems.This limitation has inhibited the full utilization of low-grade magnesium-containing minerals.This study comprehensively discusses the research progress of flotation separation technologies for magnesium-containing minerals,focusing on the crystal chemical and surface characteristics of magnesium-containing minerals and their gangue minerals,effect of inevitable ions on mineral flotation behavior,interaction effects of minerals,and research advancement of flotation reagents.The study aims to clarify the future development direction of the flotation separation of magnesium-containing minerals and provide theoretical support and technical references for an efficient separation.
基金supported by the Key Research and Development Program of Zhejiang Province Foundation(No.2019C03027)the Zhejiang Provincial Natural Science Foundation of China(No.LZ22E020002)+1 种基金the Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202148333)the Zhejiang Provincial Basic Research for Public Welfare Funds(Nos.LGF22E030002,LGF21H140001,and LTGY23H140005),China.
文摘Magnesium-doped calcium silicate(CS)bioceramic scaffolds have unique advantages in mandibular defect repair;however,they lack antibacterial properties to cope with the complex oral microbiome.Herein,for the first time,the CS scaffold was functionally modified with a novel copper-containing polydopamine(PDA(Cu^(2+)))rapid deposition method,to construct internally modified(*P),externally modified(@PDA),and dually modified(*P@PDA)scaffolds.The morphology,degradation behavior,and mechanical properties of the obtained scaffolds were evaluated in vitro.The results showed that the CS*P@PDA had a unique micro-/nano-structural surface and appreciable mechanical resistance.During the prolonged immersion stage,the release of copper ions from the CS*P@PDA scaffolds was rapid in the early stage and exhibited long-term sustained release.The in vitro evaluation revealed that the release behavior of copper ions ascribed an excellent antibacterial effect to the CS*P@PDA,while the scaffolds retained good cytocompatibility with improved osteogenesis and angiogenesis effects.Finally,the PDA(Cu^(2+))-modified scaffolds showed effective early bone regeneration in a critical-size rabbit mandibular defect model.Overall,it was indicated that considerable antibacterial property along with the enhancement of alveolar bone regeneration can be imparted to the scaffold by the two-step PDA(Cu^(2+))modification,and the convenience and wide applicability of this technique make it a promising strategy to avoid bacterial infections on implants.
