In order to utilize solid wastes,ceramic simple bricks with high performances were made from industrial solid wastes such as red mud,fly ash and poor clay shale as main raw materials in this paper.The phase compositio...In order to utilize solid wastes,ceramic simple bricks with high performances were made from industrial solid wastes such as red mud,fly ash and poor clay shale as main raw materials in this paper.The phase compositions and microstructures were tested by XRD,SEM and EPMA.The experimental results show that the water absorption is 45.64%,the porosity is 58.91%,bulk density is 1.29 g·cm-3,compressive strength is 54.91 MPa,bending strength is 29.52 MPa,freeze-thaw resistance is 29.28 MPa,specific heat capacity at constant pressure is 1.31 J·g-1·K-1,thermal diffusivity is 5.89×10-3 cm2·s-1,and thermal conductivity is 1.15×10-2 W·cm-1·K-1.These effects of additives and preparation process to the properties and microstructures were discussed in detail.The reaction mechanism was also discussed.The results of the reaction mechanism show that there has wollastonite and feldspar generated during the process of firing while Ca gathered around the feldspar,and then Ca would displace K and generated cacoclasite.展开更多
This paper examine the microstructure and the mechanical properties of maize stalk ash particles reinforced polyester composites with the aim of producing a composite material showing enhanced properties for engineeri...This paper examine the microstructure and the mechanical properties of maize stalk ash particles reinforced polyester composites with the aim of producing a composite material showing enhanced properties for engineering applications. Maize stalk ash particles (MSAp) were added in different volume fractions into a polyester matrix at 5, 10, 15 and 20% respectively. Composites samples were produced from these mixtures and the effect of the maize stalk ash content on the mechanical and microstructural properties of the composites was investigated and analyzed. Results from the scanning electron microscope (SEM) of the composites show a good and gradual interfacial bonding as the MSAp content increases while the Energy Dispersive spectrometer (EDS) and X-ray diffraction (XRD) show that carbon is present in the ash. The tensile strength, tensile modulus and compressive strength value increases as the maize stalk ash content increases but there is a gradual decrease for the impact strength. These results showed that the maize stalk ash can be used to improve the strength of polymer matrix composites for use in automobile and building applications.展开更多
This study characterizes the mechanical properties and volume fractions of the different phases in precision annealed GCr15 steel using nanoindentation technology. Experimental results indicate that the nanoindentatio...This study characterizes the mechanical properties and volume fractions of the different phases in precision annealed GCr15 steel using nanoindentation technology. Experimental results indicate that the nanoindentation hardness of cementite grains is between 14.15 GPa and 17.61 GPa,with a mean value of 15.40 GPa. This hardness is much higher than the hardness of ferrite grains. The nanoindentation hardness of ferrite is between 2.78 GPa and 4.89 GPa, with a mean value of 3.35 GPa. The volume fractions of the different phases were also determined using nanoindentation technology, and the volume fraction of cementite in the steel was identified as 15%.展开更多
Sweet potatoes have become a research focus in recent years, due to their particular nutritional and functional qualities. Considering yoghurt is one of the most popular dairy products, sweet potato supplementation wi...Sweet potatoes have become a research focus in recent years, due to their particular nutritional and functional qualities. Considering yoghurt is one of the most popular dairy products, sweet potato supplementation will play a significant impact on the produced yoghurt texture it will also add attractive orange colour to the final product. The article focused on the replacement of the stabilizers used in the manufacture of yoghurt with sweet potato flour dehydrated in a lab (SPFL) due to its functional features and a less expensive alternative and the improvement of yoghurt colour due to the presence of anthocyanin pigment. In order to reach these goals, experimental yoghurt was fortified with 0, 0.5, 1, 2, and 4 g SPFL/100g cow milk (%) and stored at 4°C for 14 days. The obtained data were then compared with commercial yoghurt samples (CS1, CS2, CS3, and CS4). Sensory evaluation revealed that the 2% SPFL, CS1, and CS3 obtained higher scores than the other treatments. The fat content of the yoghurts was identical whereas, the other physicochemical parameters and water holding capacity (WHC %) levels varied. SPFL supplementation had a significant impact on the rheological properties of yoghurt production, allowing sweet potato flour to replace the industrial stabiliser. Scanning Electron Micrograph (SEM) of yoghurt enriched with SPFL revealed denser and smaller gaps, as well as the presence of sweet potato globules embedded in and attached to the gel matrix. The results obtained in the present research imply that sweet potatoes can be used to produce a kind of cohesive and gummy yoghurt that can be used instead of industrial stabilizers.展开更多
Nd_9Fe_（85–x）Ti_4C_2B_x（x=10–15） magnetic alloys were investigated by differential thermal analysis and X-ray diffraction analysis. The results showed that with the B content increasing from 10 at.% to 15 at.%, ...Nd_9Fe_（85–x）Ti_4C_2B_x（x=10–15） magnetic alloys were investigated by differential thermal analysis and X-ray diffraction analysis. The results showed that with the B content increasing from 10 at.% to 15 at.%, the liquidus temperatures TL of the alloys decreased from 1498.5 to 1472.5 K; the solidus temperatures TS of them increased from 1353.2 to 1358.3 K; and the nucleation undercooling of the alloy melts cooled at the rate of 40 K/min decreased from 122.8 to 95.9 K, resulting in the solidification structures consisting of Nd_2Fe_（14）B, Fe_3B, α-Fe, Nd1.1Fe4B4 and TiC nanocrystallines. Furthermore, the Nd_9Fe_（85–x）Ti_4C_2B_x（x=11, 13, 15） bulk alloys in sheet form with the thickness of 0.7 mm were prepared by copper mold suction casting and their solidification characteristics and solidification structures under sub-rapidly cooling rate were investigated. The results showed that partially amorphous structures were obtained in the as-cast bulk alloys and the amount of amorphous decreased with the increase of the B content. By annealing the as-cast bulk alloys at 923 K for 10 min, the nanocomposite microstructures composed with Nd_2Fe_（14）B, Fe_3B and α-Fe nanocrystallines, which showed a single-phase hard magnetic behavior and enhanced magnetic properties, were achieved.展开更多
To acquire a well bonded interface between the copper and the diamond particles in diamondcopper matrix composites, an available process to apply a vapor deposited aluminum（Al） coating onto diamond particles was use...To acquire a well bonded interface between the copper and the diamond particles in diamondcopper matrix composites, an available process to apply a vapor deposited aluminum（Al） coating onto diamond particles was used to solve this interfacial problem. The diamond-copper matrix composites were prepared by spark plasma sintering（SPS） process and the effect of Al-coated diamond particles was demonstrated. The experimental results showed that the densification, interfacial bonding and thermal conductivity of Al-coated composites were evidently improved compared to those of the uncoated composites. A maximum thermal conductivity（TC） of 565 W/（m·K） was obtained in the coated composite containing 50vol% diamond particles sintered at 1163 K. Additionally, the experimental data of thermal conductivity and coefficient of thermal expansion（CTE） were compared with the predictions from several theoretical models.展开更多
基金Funded by the 11th Five-Year National Key Technology R&D Program(2008BAC41B00)
文摘In order to utilize solid wastes,ceramic simple bricks with high performances were made from industrial solid wastes such as red mud,fly ash and poor clay shale as main raw materials in this paper.The phase compositions and microstructures were tested by XRD,SEM and EPMA.The experimental results show that the water absorption is 45.64%,the porosity is 58.91%,bulk density is 1.29 g·cm-3,compressive strength is 54.91 MPa,bending strength is 29.52 MPa,freeze-thaw resistance is 29.28 MPa,specific heat capacity at constant pressure is 1.31 J·g-1·K-1,thermal diffusivity is 5.89×10-3 cm2·s-1,and thermal conductivity is 1.15×10-2 W·cm-1·K-1.These effects of additives and preparation process to the properties and microstructures were discussed in detail.The reaction mechanism was also discussed.The results of the reaction mechanism show that there has wollastonite and feldspar generated during the process of firing while Ca gathered around the feldspar,and then Ca would displace K and generated cacoclasite.
文摘This paper examine the microstructure and the mechanical properties of maize stalk ash particles reinforced polyester composites with the aim of producing a composite material showing enhanced properties for engineering applications. Maize stalk ash particles (MSAp) were added in different volume fractions into a polyester matrix at 5, 10, 15 and 20% respectively. Composites samples were produced from these mixtures and the effect of the maize stalk ash content on the mechanical and microstructural properties of the composites was investigated and analyzed. Results from the scanning electron microscope (SEM) of the composites show a good and gradual interfacial bonding as the MSAp content increases while the Energy Dispersive spectrometer (EDS) and X-ray diffraction (XRD) show that carbon is present in the ash. The tensile strength, tensile modulus and compressive strength value increases as the maize stalk ash content increases but there is a gradual decrease for the impact strength. These results showed that the maize stalk ash can be used to improve the strength of polymer matrix composites for use in automobile and building applications.
文摘This study characterizes the mechanical properties and volume fractions of the different phases in precision annealed GCr15 steel using nanoindentation technology. Experimental results indicate that the nanoindentation hardness of cementite grains is between 14.15 GPa and 17.61 GPa,with a mean value of 15.40 GPa. This hardness is much higher than the hardness of ferrite grains. The nanoindentation hardness of ferrite is between 2.78 GPa and 4.89 GPa, with a mean value of 3.35 GPa. The volume fractions of the different phases were also determined using nanoindentation technology, and the volume fraction of cementite in the steel was identified as 15%.
文摘Sweet potatoes have become a research focus in recent years, due to their particular nutritional and functional qualities. Considering yoghurt is one of the most popular dairy products, sweet potato supplementation will play a significant impact on the produced yoghurt texture it will also add attractive orange colour to the final product. The article focused on the replacement of the stabilizers used in the manufacture of yoghurt with sweet potato flour dehydrated in a lab (SPFL) due to its functional features and a less expensive alternative and the improvement of yoghurt colour due to the presence of anthocyanin pigment. In order to reach these goals, experimental yoghurt was fortified with 0, 0.5, 1, 2, and 4 g SPFL/100g cow milk (%) and stored at 4°C for 14 days. The obtained data were then compared with commercial yoghurt samples (CS1, CS2, CS3, and CS4). Sensory evaluation revealed that the 2% SPFL, CS1, and CS3 obtained higher scores than the other treatments. The fat content of the yoghurts was identical whereas, the other physicochemical parameters and water holding capacity (WHC %) levels varied. SPFL supplementation had a significant impact on the rheological properties of yoghurt production, allowing sweet potato flour to replace the industrial stabiliser. Scanning Electron Micrograph (SEM) of yoghurt enriched with SPFL revealed denser and smaller gaps, as well as the presence of sweet potato globules embedded in and attached to the gel matrix. The results obtained in the present research imply that sweet potatoes can be used to produce a kind of cohesive and gummy yoghurt that can be used instead of industrial stabilizers.
基金Project supported by National Natural Science Foundation of China(51174121,51274125)Zhejiang Province Science and Technology Innovation Team of Key Projects(2010R50016-30)
文摘Nd_9Fe_（85–x）Ti_4C_2B_x（x=10–15） magnetic alloys were investigated by differential thermal analysis and X-ray diffraction analysis. The results showed that with the B content increasing from 10 at.% to 15 at.%, the liquidus temperatures TL of the alloys decreased from 1498.5 to 1472.5 K; the solidus temperatures TS of them increased from 1353.2 to 1358.3 K; and the nucleation undercooling of the alloy melts cooled at the rate of 40 K/min decreased from 122.8 to 95.9 K, resulting in the solidification structures consisting of Nd_2Fe_（14）B, Fe_3B, α-Fe, Nd1.1Fe4B4 and TiC nanocrystallines. Furthermore, the Nd_9Fe_（85–x）Ti_4C_2B_x（x=11, 13, 15） bulk alloys in sheet form with the thickness of 0.7 mm were prepared by copper mold suction casting and their solidification characteristics and solidification structures under sub-rapidly cooling rate were investigated. The results showed that partially amorphous structures were obtained in the as-cast bulk alloys and the amount of amorphous decreased with the increase of the B content. By annealing the as-cast bulk alloys at 923 K for 10 min, the nanocomposite microstructures composed with Nd_2Fe_（14）B, Fe_3B and α-Fe nanocrystallines, which showed a single-phase hard magnetic behavior and enhanced magnetic properties, were achieved.
基金Funded by the National Natural Science Foundation of China(21273192)the Foundation of He’nan Educational Committee(15B430009)the Key Scientific Research Foundation of Xuchang University(2014077)
文摘To acquire a well bonded interface between the copper and the diamond particles in diamondcopper matrix composites, an available process to apply a vapor deposited aluminum（Al） coating onto diamond particles was used to solve this interfacial problem. The diamond-copper matrix composites were prepared by spark plasma sintering（SPS） process and the effect of Al-coated diamond particles was demonstrated. The experimental results showed that the densification, interfacial bonding and thermal conductivity of Al-coated composites were evidently improved compared to those of the uncoated composites. A maximum thermal conductivity（TC） of 565 W/（m·K） was obtained in the coated composite containing 50vol% diamond particles sintered at 1163 K. Additionally, the experimental data of thermal conductivity and coefficient of thermal expansion（CTE） were compared with the predictions from several theoretical models.
