A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes p...A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes possessing good bonding interface have higher shear strength than that of pure aluminum and can bear both axial and radial deformation.The original interface between aluminum layer and ferrite layer was observed by scanning electron microscopy（SEM）.The results show that the clad tubes with good bonding properties possess the interface in wave and straight shape.The Fe/Al clad tube was used to manufacture the T-shape by hydro-bulging.It is found that the good-bonding interface of the Fe/Al clad tube plays a dominant role in the formation of the T-shape.展开更多
By combining the advantages of the additive weighted mean (AWM) operator and the ordered weighted averaging (OWA) operator, this paper first presents a hybrid operator for aggregating data information, and then propos...By combining the advantages of the additive weighted mean (AWM) operator and the ordered weighted averaging (OWA) operator, this paper first presents a hybrid operator for aggregating data information, and then proposes a hybrid aggregation (HA) operator-based method for multiple attribute decision making (MADM) problems. The theoretical analyses and the numerical results show that the HA operator generalizes both the AWM and OWA operators, and reflects the importance of both the given argument and the ordered position of the argument. Thus, the HA operator can reflect better real situations in practical applications. Finally, an illustrative example is given.展开更多
In order to develop the liquid phase sintering process of WC-Ni3Al-B composites,the preparation process of WC＋Ni3Al prealloyed powder by reaction synthesis of carbonyl Ni,analytical purity Al and coarse WC powders wa...In order to develop the liquid phase sintering process of WC-Ni3Al-B composites,the preparation process of WC＋Ni3Al prealloyed powder by reaction synthesis of carbonyl Ni,analytical purity Al and coarse WC powders was investigated.DSC and XRD were adopted to study the procedure of phase transformation for the 3Ni＋Al and 70%WC＋（3Ni＋Al） mixed powders in temperature ranges of 550-1200 °C and 25-1400 °C,respectively.The results demonstrate that the formation mechanism of Ni3Al depends on the reaction temperature.Besides WC phase,there exist Ni2Al3,NiAl and Ni3Al intermetallics in the powder mixture after heat treatment at 200-660 °C,while only NiAl and Ni3Al exist at 660-1100 °C.Homogeneous WC＋Ni3Al powder mixture can be obtained in the temperature range of 1100-1200 °C.The WC-30%（Ni3Al-B） composites prepared from the mixed powders by conventional powder metallurgy technology show nearly full density and the shape of WC is round.WC-30%（Ni3Al-B） composites exhibit higher hardness of 9.7 GPa,inferior bending strength of 1800 MPa and similar fracture toughness of 18 MPa-m1/2 compared with commercial cemented carbides YGR45（WC-30%（Co-Ni-Cr））.展开更多
The growth of intermetallic compounds at the interface between solid Al and Fe and the effects of intermetallic compound layers on the interfacial bonding of clad materials were investigated. The results showed that t...The growth of intermetallic compounds at the interface between solid Al and Fe and the effects of intermetallic compound layers on the interfacial bonding of clad materials were investigated. The results showed that the interface between the solid Fe and Al formed by heat-treatment consisted of Fe2Al5 and FeAl3 intermetallic compound layers, which deteriorated the interfacial bonding strength. Fractures occurred in the intermetallic compound layer during the shear testing. The location of the fracture depended on the defects of microcracks or voids in the intermetallic compound layers. The microcracks in the intermetallic compound layer were caused by the mismatch of thermal expansion coefficients of materials during cooling, and the voids were consistent with the Kirkendall effect. The work will lay an important foundation for welding and joining of aluminum and steel, especially for fabrication of Al-Fe clad materials.展开更多
Objective To compare the long-term clinical effects of two kinds of crowns and bridges made of porcelain fused to Au-Pt alloy and Ni-Cr alloy. Methods A total of 131 teeth (64 patients) were rehabilitated using porcel...Objective To compare the long-term clinical effects of two kinds of crowns and bridges made of porcelain fused to Au-Pt alloy and Ni-Cr alloy. Methods A total of 131 teeth (64 patients) were rehabilitated using porcelain-fused-to-metal crowns, among which 59 were rehabilitated with Au-Pt alloy metal ceramic crown and 72 with Ni-Cr alloy metal ceramic crown. The porcelain fracture, shade, marginal adaptation, gingival discoloration, and gingival status after finishing restoration and 36 months of follow-up were evaluated. Results After 36 months of restoration, porcelain fused to Au-Pt alloy crown showed better clinical effects than porcelain fused to Ni-Cr alloy crown in shade, marginal adaptation, gingival discoloration, as well as gingival status (all P<0.05). Conclusion The Au-Pt alloy ceramic crown is superior to Ni-Cr alloy ceramic crown in long-term clinical effects.展开更多
Microstructures of laminates produced by epoxy/carbon fibers with different fiber volume fraction were studied by analyzing the composite cross-sections.The main result of the compaction of reinforcement is the flatti...Microstructures of laminates produced by epoxy/carbon fibers with different fiber volume fraction were studied by analyzing the composite cross-sections.The main result of the compaction of reinforcement is the flatting of bundle shape,the reducing of gap and the embedment of bundles among each layer.The void content outside the bundle decreased sharply during the compaction until it is less than that inside the bundle when the fiber volume fraction is over 60%.The resin flow velocity in the fiber tow is 102-104 times greater than the flow velocity out the fiber tow no matter the capillary pressure is taken into account or not.展开更多
Transition metal oxides with 4d or 5d metals are of great interest due to the competing interactions, of the Coulomb repulsion and the itineracy of the d-electrons, opening a possibility of building new quantum ground...Transition metal oxides with 4d or 5d metals are of great interest due to the competing interactions, of the Coulomb repulsion and the itineracy of the d-electrons, opening a possibility of building new quantum ground states. Particularly the 5d metal oxides containing Iridium have received significant attention within the last years, due to their unexpected physical properties, caused by a strong spin orbit coupling observed in It（IV）. A prominent example is the Mott-insulator Sr2IrO4. Another member of this family, the honeycomb lattice compound Na2IrO3, also being a Mott-insulator having, most probably, a Kitaev spin liquid ground state. By deintercalating sodium from Na2IrO3, the authors were able to synthesize a new honeycomb lattice compound with more than 50% reduced sodium content. The reduction of the sodium content in this layered compound leads to a change of the oxidation state of iridium from ＋ IV to ＋ V/＋ VI and a symmetry change from C2/c to P-3. This goes along with significant changes of the physical properties. Besides the vanishing magnetic ordering at 15 K, also the transport properties changes and instead insulating semiconducting properties are observed.展开更多
Investigating the microstructures and properties of gradient materials has been regarded as a promising way to accelerate the identification of optimal compositions for applications. Herein, a supergravity method is a...Investigating the microstructures and properties of gradient materials has been regarded as a promising way to accelerate the identification of optimal compositions for applications. Herein, a supergravity method is applied to prepare the graded entropic alloys Al-Zn-Li-Mg-Cu. Through carefully optimizing the experimental conditions, the graded microstructures and hardness values appear after the supergravity technique. The morphology of the alloy significantly changes from the bulk intermetallics to eutectic structures along the supergravity force direction, which results from the crushed and graded aluminum oxide combined with the extremelystrong force. The results show that with this supergravity method, a performance-enhanced alloy can potentially be achieved through the centrifugation in a short time span and thus it paves the way for designing and synthesizing entropic alloys with intriguing properties.展开更多
A novel 3D metal-organic framework(MOF) with remarkable thermal stability,Ni(BIC)2.2·5H2O(JUC-86)(HBIC = 1-H-benzimidazole-5-carboxylic acid and JUC = Jilin University China),has been synthesized under hydrotherm...A novel 3D metal-organic framework(MOF) with remarkable thermal stability,Ni(BIC)2.2·5H2O(JUC-86)(HBIC = 1-H-benzimidazole-5-carboxylic acid and JUC = Jilin University China),has been synthesized under hydrothermal conditions.It crystallizes in tetragonal symmetry with P43212 space group.The 3D structure consists of channels assembled from triple helices with a 4.5 × 4.52 aperture,which are formed by the parallel alignment of three infinite helical chains.The thermogravimetric analysis(TGA) and powder X-ray diffractions(PXRD) indicate JUC-86 with high thermal stability(up to 350 ℃).展开更多
Three novel transition metal complexes [ML2（phen）]＇H20 （M= Mn, Co, Zn; HL= C10H702NSe, 2-phenyl-4-selenazole carboxylic acid, phen= 1,10-phenanthroline） 1-3 were synthesized and characterized by elemental analysi...Three novel transition metal complexes [ML2（phen）]＇H20 （M= Mn, Co, Zn; HL= C10H702NSe, 2-phenyl-4-selenazole carboxylic acid, phen= 1,10-phenanthroline） 1-3 were synthesized and characterized by elemental analysis, IR spectra. Their crystal structures were deterimined by single-crystal X-ray diffraction method. The antibacterial activities of the complexes against five species of bacteria, Escherichia coli （E. coli）, Staphylococcus epidermidis （S. epidermidis）, Staphylococcus aureus （S. au- reus）, Acinetobacter baumanii （A. baumanii） and Streptococcus viridans （S. viridans）, were tested respectively. The anticancer activities of the complexes against human pancreatic cancer line PANC-28 and human hepatocarcinoma line HuH7 were also studied. The interactions between the complexes and DNA were studied by ethidium bromide （EB） fluorescent probe.展开更多
基金Project(BA2006067)supported by Achievement Transitional Foundation of Jiangsu Province,China
文摘A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes possessing good bonding interface have higher shear strength than that of pure aluminum and can bear both axial and radial deformation.The original interface between aluminum layer and ferrite layer was observed by scanning electron microscopy（SEM）.The results show that the clad tubes with good bonding properties possess the interface in wave and straight shape.The Fe/Al clad tube was used to manufacture the T-shape by hydro-bulging.It is found that the good-bonding interface of the Fe/Al clad tube plays a dominant role in the formation of the T-shape.
文摘By combining the advantages of the additive weighted mean (AWM) operator and the ordered weighted averaging (OWA) operator, this paper first presents a hybrid operator for aggregating data information, and then proposes a hybrid aggregation (HA) operator-based method for multiple attribute decision making (MADM) problems. The theoretical analyses and the numerical results show that the HA operator generalizes both the AWM and OWA operators, and reflects the importance of both the given argument and the ordered position of the argument. Thus, the HA operator can reflect better real situations in practical applications. Finally, an illustrative example is given.
基金Project (2012CB723906) supported by the National Basic Research Program of China
文摘In order to develop the liquid phase sintering process of WC-Ni3Al-B composites,the preparation process of WC＋Ni3Al prealloyed powder by reaction synthesis of carbonyl Ni,analytical purity Al and coarse WC powders was investigated.DSC and XRD were adopted to study the procedure of phase transformation for the 3Ni＋Al and 70%WC＋（3Ni＋Al） mixed powders in temperature ranges of 550-1200 °C and 25-1400 °C,respectively.The results demonstrate that the formation mechanism of Ni3Al depends on the reaction temperature.Besides WC phase,there exist Ni2Al3,NiAl and Ni3Al intermetallics in the powder mixture after heat treatment at 200-660 °C,while only NiAl and Ni3Al exist at 660-1100 °C.Homogeneous WC＋Ni3Al powder mixture can be obtained in the temperature range of 1100-1200 °C.The WC-30%（Ni3Al-B） composites prepared from the mixed powders by conventional powder metallurgy technology show nearly full density and the shape of WC is round.WC-30%（Ni3Al-B） composites exhibit higher hardness of 9.7 GPa,inferior bending strength of 1800 MPa and similar fracture toughness of 18 MPa-m1/2 compared with commercial cemented carbides YGR45（WC-30%（Co-Ni-Cr））.
基金Project(2011DFR50630)sponsored by the International S&T Cooperation of China
文摘The growth of intermetallic compounds at the interface between solid Al and Fe and the effects of intermetallic compound layers on the interfacial bonding of clad materials were investigated. The results showed that the interface between the solid Fe and Al formed by heat-treatment consisted of Fe2Al5 and FeAl3 intermetallic compound layers, which deteriorated the interfacial bonding strength. Fractures occurred in the intermetallic compound layer during the shear testing. The location of the fracture depended on the defects of microcracks or voids in the intermetallic compound layers. The microcracks in the intermetallic compound layer were caused by the mismatch of thermal expansion coefficients of materials during cooling, and the voids were consistent with the Kirkendall effect. The work will lay an important foundation for welding and joining of aluminum and steel, especially for fabrication of Al-Fe clad materials.
文摘Objective To compare the long-term clinical effects of two kinds of crowns and bridges made of porcelain fused to Au-Pt alloy and Ni-Cr alloy. Methods A total of 131 teeth (64 patients) were rehabilitated using porcelain-fused-to-metal crowns, among which 59 were rehabilitated with Au-Pt alloy metal ceramic crown and 72 with Ni-Cr alloy metal ceramic crown. The porcelain fracture, shade, marginal adaptation, gingival discoloration, and gingival status after finishing restoration and 36 months of follow-up were evaluated. Results After 36 months of restoration, porcelain fused to Au-Pt alloy crown showed better clinical effects than porcelain fused to Ni-Cr alloy crown in shade, marginal adaptation, gingival discoloration, as well as gingival status (all P<0.05). Conclusion The Au-Pt alloy ceramic crown is superior to Ni-Cr alloy ceramic crown in long-term clinical effects.
基金The Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,Science and Technology Commission of Shanghai Municipality,China(No.06QA14001)
文摘Microstructures of laminates produced by epoxy/carbon fibers with different fiber volume fraction were studied by analyzing the composite cross-sections.The main result of the compaction of reinforcement is the flatting of bundle shape,the reducing of gap and the embedment of bundles among each layer.The void content outside the bundle decreased sharply during the compaction until it is less than that inside the bundle when the fiber volume fraction is over 60%.The resin flow velocity in the fiber tow is 102-104 times greater than the flow velocity out the fiber tow no matter the capillary pressure is taken into account or not.
文摘Transition metal oxides with 4d or 5d metals are of great interest due to the competing interactions, of the Coulomb repulsion and the itineracy of the d-electrons, opening a possibility of building new quantum ground states. Particularly the 5d metal oxides containing Iridium have received significant attention within the last years, due to their unexpected physical properties, caused by a strong spin orbit coupling observed in It（IV）. A prominent example is the Mott-insulator Sr2IrO4. Another member of this family, the honeycomb lattice compound Na2IrO3, also being a Mott-insulator having, most probably, a Kitaev spin liquid ground state. By deintercalating sodium from Na2IrO3, the authors were able to synthesize a new honeycomb lattice compound with more than 50% reduced sodium content. The reduction of the sodium content in this layered compound leads to a change of the oxidation state of iridium from ＋ IV to ＋ V/＋ VI and a symmetry change from C2/c to P-3. This goes along with significant changes of the physical properties. Besides the vanishing magnetic ordering at 15 K, also the transport properties changes and instead insulating semiconducting properties are observed.
基金the financial support from the National Natural Science Foundation of China (NSFC, 51471025 and 51671020)
文摘Investigating the microstructures and properties of gradient materials has been regarded as a promising way to accelerate the identification of optimal compositions for applications. Herein, a supergravity method is applied to prepare the graded entropic alloys Al-Zn-Li-Mg-Cu. Through carefully optimizing the experimental conditions, the graded microstructures and hardness values appear after the supergravity technique. The morphology of the alloy significantly changes from the bulk intermetallics to eutectic structures along the supergravity force direction, which results from the crushed and graded aluminum oxide combined with the extremelystrong force. The results show that with this supergravity method, a performance-enhanced alloy can potentially be achieved through the centrifugation in a short time span and thus it paves the way for designing and synthesizing entropic alloys with intriguing properties.
基金supported by the National Basic Research Program of china (2011CB808703)the National Natural Science Foundation of China (91022030)+1 种基金"111" project(B07016)Jilin Young Scientist Foundation (20090131)
文摘A novel 3D metal-organic framework(MOF) with remarkable thermal stability,Ni(BIC)2.2·5H2O(JUC-86)(HBIC = 1-H-benzimidazole-5-carboxylic acid and JUC = Jilin University China),has been synthesized under hydrothermal conditions.It crystallizes in tetragonal symmetry with P43212 space group.The 3D structure consists of channels assembled from triple helices with a 4.5 × 4.52 aperture,which are formed by the parallel alignment of three infinite helical chains.The thermogravimetric analysis(TGA) and powder X-ray diffractions(PXRD) indicate JUC-86 with high thermal stability(up to 350 ℃).
基金financially supported by Natural Science Foundation of Zhejiang Province (Y4080256)
文摘Three novel transition metal complexes [ML2（phen）]＇H20 （M= Mn, Co, Zn; HL= C10H702NSe, 2-phenyl-4-selenazole carboxylic acid, phen= 1,10-phenanthroline） 1-3 were synthesized and characterized by elemental analysis, IR spectra. Their crystal structures were deterimined by single-crystal X-ray diffraction method. The antibacterial activities of the complexes against five species of bacteria, Escherichia coli （E. coli）, Staphylococcus epidermidis （S. epidermidis）, Staphylococcus aureus （S. au- reus）, Acinetobacter baumanii （A. baumanii） and Streptococcus viridans （S. viridans）, were tested respectively. The anticancer activities of the complexes against human pancreatic cancer line PANC-28 and human hepatocarcinoma line HuH7 were also studied. The interactions between the complexes and DNA were studied by ethidium bromide （EB） fluorescent probe.
