The microstructures and damping property of supersaturated ZnA127Ce alloy during natural aging have been investigated. H-800 TEM was mainly used to research the microstructures. The relationship between microstructure...The microstructures and damping property of supersaturated ZnA127Ce alloy during natural aging have been investigated. H-800 TEM was mainly used to research the microstructures. The relationship between microstructure and damping property was primarily studied. The results showed that solution plus natural aging was the best heat treatment, which could improve the damping property. Both continuous precipitation and cellular reaction occurred during the aging. Continuous precipitation follows the sequence: β→spherical GP zones→elliptical GP zones→intermediate phase R→n. The cellular reaction can be written as follows:β→a+n+ε.展开更多
Curcumin is a natural polyphenol that is used in various traditional medicines.However,its inherent properties,such as its rapid degradation and metabolism,low bioavailability,and short half-life,are serious problems ...Curcumin is a natural polyphenol that is used in various traditional medicines.However,its inherent properties,such as its rapid degradation and metabolism,low bioavailability,and short half-life,are serious problems that must be resolved.To this end,a drug carrier incorporating natural magnetic cores in a zeolite framework was developed and applied to the loading of curcumin in ethanol solutions.In this system,curcumin is encapsulated in a zeolite Na(ZNA)magnetic core–shell structure(Fe@Si/ZNA),which can be easily synthesized using an in situ method.Synthesis of Fe_(3)O_(4) nanoparticles was carried out from natural materials using a co-precipitation method.Analysis of the prepared magnetic core–shell structures and composites was carried out using vibrating-sample magnetometery,Fourier transform infrared spectroscopy,transmission electron microscopy,and x-ray diffraction.The cumulative loading of curcumin in the ZNA composite with 9%nanoparticles was found to reach 90.70%with a relatively long half-life of 32.49 min.Stability tests of curcumin loading in the composite showed that adding magnetic particles to the zeolite framework also increased the stability of the composite structure.Adsorption kinetics and isotherm studies also found that the system follows the pseudo-second-order and Langmuir isotherm models.展开更多
Based on the structure and dimensions of a vertical ZnO nanorod array(V-ZNA)sample,an ideal 2-D photonic crystal model was established.The optical properties of the V-ZNAs were analyzed with finite-difference time-dom...Based on the structure and dimensions of a vertical ZnO nanorod array(V-ZNA)sample,an ideal 2-D photonic crystal model was established.The optical properties of the V-ZNAs were analyzed with finite-difference time-domain(FDTD)method,and the influences of the geometry parameters,including the circumcircle diameters of the top and bottom surfaces(Dt and Db)and the height(H)of the nanorods,and the pitch between each column(L),were discussed.High transmittance and low reflectance in the waveband of 400–800 nm were proved,and the highest transmittance can be obtained with Dt<50 nm,H=200 nm,and Db/L=0.85,which was verified by Effective Index Method(EIM).The result indicates that V-ZNAs can be used as excellent light coupling element and antireflection material for solar energy applications.展开更多
文摘The microstructures and damping property of supersaturated ZnA127Ce alloy during natural aging have been investigated. H-800 TEM was mainly used to research the microstructures. The relationship between microstructure and damping property was primarily studied. The results showed that solution plus natural aging was the best heat treatment, which could improve the damping property. Both continuous precipitation and cellular reaction occurred during the aging. Continuous precipitation follows the sequence: β→spherical GP zones→elliptical GP zones→intermediate phase R→n. The cellular reaction can be written as follows:β→a+n+ε.
基金funding from the Ministry of Education,Culture,Research,and Technology,Indonesia,through the PDKN Research Grant with Contract No.041/E5/PG.02.00.PL/2023.
文摘Curcumin is a natural polyphenol that is used in various traditional medicines.However,its inherent properties,such as its rapid degradation and metabolism,low bioavailability,and short half-life,are serious problems that must be resolved.To this end,a drug carrier incorporating natural magnetic cores in a zeolite framework was developed and applied to the loading of curcumin in ethanol solutions.In this system,curcumin is encapsulated in a zeolite Na(ZNA)magnetic core–shell structure(Fe@Si/ZNA),which can be easily synthesized using an in situ method.Synthesis of Fe_(3)O_(4) nanoparticles was carried out from natural materials using a co-precipitation method.Analysis of the prepared magnetic core–shell structures and composites was carried out using vibrating-sample magnetometery,Fourier transform infrared spectroscopy,transmission electron microscopy,and x-ray diffraction.The cumulative loading of curcumin in the ZNA composite with 9%nanoparticles was found to reach 90.70%with a relatively long half-life of 32.49 min.Stability tests of curcumin loading in the composite showed that adding magnetic particles to the zeolite framework also increased the stability of the composite structure.Adsorption kinetics and isotherm studies also found that the system follows the pseudo-second-order and Langmuir isotherm models.
基金supported by the National Basic Research Program of China("973" Project)(Grant No.2009CB939904)the Fundamental Research Funds for the Central Universitiesthe Key Laboratory of Inorganic Coating Materials,Chinese Academy of Sciences
文摘Based on the structure and dimensions of a vertical ZnO nanorod array(V-ZNA)sample,an ideal 2-D photonic crystal model was established.The optical properties of the V-ZNAs were analyzed with finite-difference time-domain(FDTD)method,and the influences of the geometry parameters,including the circumcircle diameters of the top and bottom surfaces(Dt and Db)and the height(H)of the nanorods,and the pitch between each column(L),were discussed.High transmittance and low reflectance in the waveband of 400–800 nm were proved,and the highest transmittance can be obtained with Dt<50 nm,H=200 nm,and Db/L=0.85,which was verified by Effective Index Method(EIM).The result indicates that V-ZNAs can be used as excellent light coupling element and antireflection material for solar energy applications.
