纯聚偏氟乙烯-六氟丙烯共聚物(PVDF-HFP)基凝胶电解质常常受制于低离子电导率,阻碍了其在染料敏化太阳电池(dye-sensitized solar cells,DSSCs)中的应用。而利用纳米填充可提高凝胶电解质离子电导率及凝胶电解质DSSCs的性能。本文使用...纯聚偏氟乙烯-六氟丙烯共聚物(PVDF-HFP)基凝胶电解质常常受制于低离子电导率,阻碍了其在染料敏化太阳电池(dye-sensitized solar cells,DSSCs)中的应用。而利用纳米填充可提高凝胶电解质离子电导率及凝胶电解质DSSCs的性能。本文使用功能化的多壁碳纳米管(f-MWCNT)作为PVDF-HFP凝胶电解质的纳米填充物,通过改变f-MWCNT的质量分数来研究其对电解质的离子电导率和离子扩散的影响,进而研究其对DSSCs的转化效率和长期稳定性的增强作用。研究发现:质量分数0.5%的f-MWCNT明显提高了 PVDF-HFP 凝胶电解质的离子电导率和离子扩散系数。并且,该凝胶电解质基DSSCs的光转换效率可达5.28%,相比于未填充的PVDF-HFP凝胶电解质基DSSCs(4.01%),其效率提高了31.7%。 42 d后,该电池依然可以保持最初转化效率的86.5%。实验结果证实了f-MWCNT在纳米填充方面的巨大潜能,为采用纳米填充物提高凝胶电解质DSSCs的性能提供参考。展开更多
Zr-based bulk metallic glass matrix composites （BMGMCs） with a composition of Zr60.0Ti14.7Nb5.3Cu5.6Ni4.4- Be10.0 （at%） were fabricated by an innovative process, i.e., semisolid processing plus Bridgman solidifica...Zr-based bulk metallic glass matrix composites （BMGMCs） with a composition of Zr60.0Ti14.7Nb5.3Cu5.6Ni4.4- Be10.0 （at%） were fabricated by an innovative process, i.e., semisolid processing plus Bridgman solidification. Different morphologies, distributions, and volume fractions of the crystalline phases can be achieved by tailoring the withdrawal velocity. The largest fi-acture strain of Zr60.0Ti14.7Nb5.3Cu5.6Ni4.4Be10.0 （at%） composites with the withdrawal velocity of 1.0 mm/s was found to be 16.7%. The mechanism of plasticity improvement is mainly attributed to the interpenetrated structure of the crystalline phase, which greatly confines the rapid propagation of shear bands.展开更多
Gold nanoparticles-dimethylsiloxane(AuNPs-PDMS) membrane is a novel composite material in biochemical technology an d micro-electro-mechanical system(MEMS) research.It is widely used in biomed ici ne,biochemical detec...Gold nanoparticles-dimethylsiloxane(AuNPs-PDMS) membrane is a novel composite material in biochemical technology an d micro-electro-mechanical system(MEMS) research.It is widely used in biomed ici ne,biochemical detection and en vironmental protection due to its biocompatibility,elasticity and electric char acteristics.In this paper,the characteristics of the composite membrane were d escribed,and four methods for fabricating AuNPs-PDMS composite membranes were reviewed in detail.Besides,the advantages and disadvantages of the four method s were summarized,and the present problems and future researches were proposed.展开更多
The dynamic mechanical behaviors of hollow Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 bulk metal glass (BMG) are investigated using a splitting Hopkinson pressure bar (SHPB) in this study. Upon dynamic compressive loading, the ho...The dynamic mechanical behaviors of hollow Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 bulk metal glass (BMG) are investigated using a splitting Hopkinson pressure bar (SHPB) in this study. Upon dynamic compressive loading, the hollow specimen exhibit lower strength and poor ductility, caused by the higher stress concentration for the hollow one through FEM modeling. The different strain-rate responses for the hollow specimen are compared and explained. On the fracture surface of the hollow samples, there are highly dense vein patterns, many liquid drops and fishbone-like patterns.展开更多
A novel and facile oxidation-induced self-doping process of graphene-silicon Schottky junction by nitric acid（HNO3） vapor is reported. The HNO3 oxidation process makes graphene p-type self-doped, and leads to a high...A novel and facile oxidation-induced self-doping process of graphene-silicon Schottky junction by nitric acid（HNO3） vapor is reported. The HNO3 oxidation process makes graphene p-type self-doped, and leads to a higher built-in potential and conductivity to enhance charge transfer and to suppress charge carrier recombination at the graphene-silicon Schottky junction. After the HNO3 oxidation process, the open-circuit voltage is increased from the initial value of 0.36 V to the maximum value of 0.47 V, the short-circuit current is greatly increased from 0.80μA to 7.71μA, and the ideality factor is optimized from 4.4 to 1.0. The enhancement of the performance of graphene-Si solar cells may be due to oxidation-induced p-type self-doping of graphene-Si junctions.展开更多
Cartilage has limited self-repair ability due to its avascular,alymphatic and aneural features.The combination of three-dimensional(3D)printing and tissue engineering provides an up-and-coming approach to address this...Cartilage has limited self-repair ability due to its avascular,alymphatic and aneural features.The combination of three-dimensional(3D)printing and tissue engineering provides an up-and-coming approach to address this issue.Here,we designed and fabricated a tri-layered(superficial layer(SL),middle layer(ML)and deep layer(DL))stratified scaffold,inspired by the architecture of collagen fibers in native cartilage tissue.The scaffold was composed of 3D printed depth-dependent gradient poly(e-caprolactone)(PCL)impregnated with methacrylated alginate(ALMA),and its morphological analysis and mechanical properties were tested.To prove the feasibility of the composite scaffolds for cartilage regeneration,the viability,proliferation,collagen deposition and chondrogenic differentiation of embedded rat bone marrow mesenchymal stem cells(BMSCs)in the scaffolds were assessed by Live/dead assay,CCK-8,DNA content,cell morphology,immunofluorescence and real-time reverse transcription polymerase chain reaction.BMSCs-loaded gradient PCL/ALMA scaffolds showed excellent cell survival,cell proliferation,cell morphology,collagen II deposition and hopeful chondrogenic differentiation compared with three individual-layer scaffolds.Hence,our study demonstrates the potential use of the gradient PCL/ALMA construct for enhanced cartilage tissue engineering.展开更多
基金financial support of the National Natural Science Foundation of China (Nos. 51101110 and 51105267)the Youth Science Foundation of Shanxi Province, China (Nos. 2012021018-1 and 2012021013-1)the Research Project Supported by Shanxi Scholarship Council of China (Nos. 2012-032 and 2012-030)
文摘Zr-based bulk metallic glass matrix composites （BMGMCs） with a composition of Zr60.0Ti14.7Nb5.3Cu5.6Ni4.4- Be10.0 （at%） were fabricated by an innovative process, i.e., semisolid processing plus Bridgman solidification. Different morphologies, distributions, and volume fractions of the crystalline phases can be achieved by tailoring the withdrawal velocity. The largest fi-acture strain of Zr60.0Ti14.7Nb5.3Cu5.6Ni4.4Be10.0 （at%） composites with the withdrawal velocity of 1.0 mm/s was found to be 16.7%. The mechanism of plasticity improvement is mainly attributed to the interpenetrated structure of the crystalline phase, which greatly confines the rapid propagation of shear bands.
基金National Natural Science Foundation of China (No.51105267, No.91123036)China Postdoctoral Science Foundation(No.2011M500542, No.2012T50248)+1 种基金National Research Foundation for the Doctoral Program of Higher Education of China (No.20111402120007)Shanxi Provincial Foundation for Returned Scholars (No.2011x10)
文摘Gold nanoparticles-dimethylsiloxane(AuNPs-PDMS) membrane is a novel composite material in biochemical technology an d micro-electro-mechanical system(MEMS) research.It is widely used in biomed ici ne,biochemical detection and en vironmental protection due to its biocompatibility,elasticity and electric char acteristics.In this paper,the characteristics of the composite membrane were d escribed,and four methods for fabricating AuNPs-PDMS composite membranes were reviewed in detail.Besides,the advantages and disadvantages of the four method s were summarized,and the present problems and future researches were proposed.
文摘The dynamic mechanical behaviors of hollow Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 bulk metal glass (BMG) are investigated using a splitting Hopkinson pressure bar (SHPB) in this study. Upon dynamic compressive loading, the hollow specimen exhibit lower strength and poor ductility, caused by the higher stress concentration for the hollow one through FEM modeling. The different strain-rate responses for the hollow specimen are compared and explained. On the fracture surface of the hollow samples, there are highly dense vein patterns, many liquid drops and fishbone-like patterns.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61504113,61674113 and 51622507the Natural Science Foundation of Shanxi Province under Grant No 2016011040+1 种基金the Natural Science Foundation of Fujian Province under Grant No 2018J01567the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province under Grant No 2016138
文摘A novel and facile oxidation-induced self-doping process of graphene-silicon Schottky junction by nitric acid（HNO3） vapor is reported. The HNO3 oxidation process makes graphene p-type self-doped, and leads to a higher built-in potential and conductivity to enhance charge transfer and to suppress charge carrier recombination at the graphene-silicon Schottky junction. After the HNO3 oxidation process, the open-circuit voltage is increased from the initial value of 0.36 V to the maximum value of 0.47 V, the short-circuit current is greatly increased from 0.80μA to 7.71μA, and the ideality factor is optimized from 4.4 to 1.0. The enhancement of the performance of graphene-Si solar cells may be due to oxidation-induced p-type self-doping of graphene-Si junctions.
基金This study was supported by the National Natural Science Foundation of China(Nos 51975400,61703298,61501316,51505324)National Key Research and Development Program(2019YFB1310200)+1 种基金Shanxi Provincial Key Research and Development Project(201803D421050)Beijing Natural Science Foundation(7202190).
文摘Cartilage has limited self-repair ability due to its avascular,alymphatic and aneural features.The combination of three-dimensional(3D)printing and tissue engineering provides an up-and-coming approach to address this issue.Here,we designed and fabricated a tri-layered(superficial layer(SL),middle layer(ML)and deep layer(DL))stratified scaffold,inspired by the architecture of collagen fibers in native cartilage tissue.The scaffold was composed of 3D printed depth-dependent gradient poly(e-caprolactone)(PCL)impregnated with methacrylated alginate(ALMA),and its morphological analysis and mechanical properties were tested.To prove the feasibility of the composite scaffolds for cartilage regeneration,the viability,proliferation,collagen deposition and chondrogenic differentiation of embedded rat bone marrow mesenchymal stem cells(BMSCs)in the scaffolds were assessed by Live/dead assay,CCK-8,DNA content,cell morphology,immunofluorescence and real-time reverse transcription polymerase chain reaction.BMSCs-loaded gradient PCL/ALMA scaffolds showed excellent cell survival,cell proliferation,cell morphology,collagen II deposition and hopeful chondrogenic differentiation compared with three individual-layer scaffolds.Hence,our study demonstrates the potential use of the gradient PCL/ALMA construct for enhanced cartilage tissue engineering.
