It is important to determine the isoflavone components by high-performance liquid chromatography （HPLC） for the molecular assistant selection of isoflavone in soybean. Based on the standard samples of 12 isoflavone ...It is important to determine the isoflavone components by high-performance liquid chromatography （HPLC） for the molecular assistant selection of isoflavone in soybean. Based on the standard samples of 12 isoflavone components, the isoflavone components were analyzed using the determination of absorbance peaks method by HPLC. The results showed that there were different maximum ultraviolet （UV） absorbance for the aglycones of daidzein, glycitein, and genistein, which were at 250, 257, and 260 nm, respectively. A linear gradient elution of acetonitrile （13-30%） containing 0. 1% acetic acid as a mobile phase was applied on a YMC-C18 column at 35℃. The 12 isoflavone components were determined using the UV detector by HPLC. We concluded that this is a rapid and precise method which adapted to determine the large numbers of samples with microanalysis.展开更多
High-density integration technologies with copper(Cu)through-silicon via(TSV)have emerged as viable alternatives for achieving the requisite integration densities for the portable electronics and micro-electro-mechani...High-density integration technologies with copper(Cu)through-silicon via(TSV)have emerged as viable alternatives for achieving the requisite integration densities for the portable electronics and micro-electro-mechanical systems(MEMSs)package.However,significant thermo-mechanical stresses can be introduced in integrated structures during the manufacturing process due to mismatches of thermal expansion and the mechanical properties between Cu and silicon(Si).The high-density integration demands an interconnection material with a strong mechanical strength and small thermal expansion mismatch.In this study,a novel electroplating method is developed for the synthesis of a graphene-copper(G-Cu)composite with electrochemically exfoliated graphenes.The fabrication and evaluation of the G-Cu composite microstructures,including the microcantilevers and micromirrors supported by the composite,are reported.We evaluated not only the micromechanical properties of the G-Cu composite based on in-situ mechanical resonant frequency measurements using a laser Doppler vibrometer but also the coefficients of thermal expansion(CTE)of the composite based on curvature radius measurements at a temperature range of 20–200℃.The Young’s modulus and shear modulus of the composite are approximately 123 and 51 GPa,which are 1.25 times greater and 1.22 times greater,respectively,than those of pure Cu due to the reinforcement of graphene.The G-Cu composite exhibits a 23%lower CTE than Cu without sacrificing electrical conductivity.These results show that the mechanically strengthened G-Cu composite with reduced thermal expansion is an ideal and reliable interconnection material instead of Cu for complex integration structures.展开更多
基金supported by grants from the National Transgenic Plants Program of China (2008ZX08004-003)the National High-Tech R&D Program (863Program, 2006AA100104)the National Natural Science Foundation of China (30000107)
文摘It is important to determine the isoflavone components by high-performance liquid chromatography （HPLC） for the molecular assistant selection of isoflavone in soybean. Based on the standard samples of 12 isoflavone components, the isoflavone components were analyzed using the determination of absorbance peaks method by HPLC. The results showed that there were different maximum ultraviolet （UV） absorbance for the aglycones of daidzein, glycitein, and genistein, which were at 250, 257, and 260 nm, respectively. A linear gradient elution of acetonitrile （13-30%） containing 0. 1% acetic acid as a mobile phase was applied on a YMC-C18 column at 35℃. The 12 isoflavone components were determined using the UV detector by HPLC. We concluded that this is a rapid and precise method which adapted to determine the large numbers of samples with microanalysis.
基金Part of this study was performed at the Micro/Nanomachining Research Education Center(MNC)and Micro System Integration Center(μSIC)of Tohoku UniversityThis research was supported by a Grant-in-Aid from the Japanese Ministry of Education,Culture,Sports,Science and Technology and partly supported by Special Coordination Funds for Promoting Science and Technology and the Formation of Innovation Center for Fusion of Advanced TechnologiesThis study was supported by the Council for Science,Technology and Innovation(CSTI)and Cross-ministerial Strategic Innovation Promotion Program(SIP).
文摘High-density integration technologies with copper(Cu)through-silicon via(TSV)have emerged as viable alternatives for achieving the requisite integration densities for the portable electronics and micro-electro-mechanical systems(MEMSs)package.However,significant thermo-mechanical stresses can be introduced in integrated structures during the manufacturing process due to mismatches of thermal expansion and the mechanical properties between Cu and silicon(Si).The high-density integration demands an interconnection material with a strong mechanical strength and small thermal expansion mismatch.In this study,a novel electroplating method is developed for the synthesis of a graphene-copper(G-Cu)composite with electrochemically exfoliated graphenes.The fabrication and evaluation of the G-Cu composite microstructures,including the microcantilevers and micromirrors supported by the composite,are reported.We evaluated not only the micromechanical properties of the G-Cu composite based on in-situ mechanical resonant frequency measurements using a laser Doppler vibrometer but also the coefficients of thermal expansion(CTE)of the composite based on curvature radius measurements at a temperature range of 20–200℃.The Young’s modulus and shear modulus of the composite are approximately 123 and 51 GPa,which are 1.25 times greater and 1.22 times greater,respectively,than those of pure Cu due to the reinforcement of graphene.The G-Cu composite exhibits a 23%lower CTE than Cu without sacrificing electrical conductivity.These results show that the mechanically strengthened G-Cu composite with reduced thermal expansion is an ideal and reliable interconnection material instead of Cu for complex integration structures.
