Stearic acid (67.83℃) and myristic acid (52.32℃) have high melting temperatures that can limit their use as phase change material (PCM) in low temperature solar heating applications such as solar space and greenhous...Stearic acid (67.83℃) and myristic acid (52.32℃) have high melting temperatures that can limit their use as phase change material (PCM) in low temperature solar heating applications such as solar space and greenhouse heating in regard to climatic requirements. However, their melting temperatures can be adjusted to a suitable value by preparing a eutectic mixture of the myristic acid (MA) and the stearic acid (SA). In the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of myristic acid (MA) and stearic acid (SA) in the respective composition (by mass) of 64% and 36% forms a eutectic mixture having melting temperature of 44.13℃ and the latent heat of fusion of 182.4J·g-1. The thermal energy storage characteristics of the MA-SA eutectic mixture filled in the annulus of two concentric pipes were also experimentally established. The heat recovery rate and heat charging/discharging fractions were determined with respect to the change in the mass flow rate and the inlet temperature of heat transfer fluid. Based on the results obtained by DSC analysis and by the heat charg- ing/discharging processes of the PCM, it can be concluded that the MA-SA eutectic mixture is a potential material for low temperature thermal energy storage applications in terms of its thermo-physical and thermal characteristics.展开更多
This article presents the evidence in support of the direct magma degassing as the principal mechanism of volatiles releasing into the hydrothermal fluids in the Okinawa Trough, as contrasted to the argument for the h...This article presents the evidence in support of the direct magma degassing as the principal mechanism of volatiles releasing into the hydrothermal fluids in the Okinawa Trough, as contrasted to the argument for the hydrothermal stripping of volatiles from the volcanic rocks.\ Laser Raman microprobe and stepped-heating techniques are employed to determine the compositions and contents of the volatiles in pumices in the middle Okinawa Trough. The results show that the volatiles are similar to the gases in the hydrothermal fluids and hydrothermal minerals in composition, the mean percent content of each component and variation trend. This indicates the direct influence of magma degassing on the hydrothermal fluids. In addition, the contents of volatiles in pumices are rather low and do not support the hydrothermal stripping as the main mechanism to enrich the fluids with gases. The results are consistent with the idea that the direct magma degassing is more important than hydrothermal stripping in supplying gases to the hydrothermal fluids in the Okinawa Trough.展开更多
The Yixian Formation is a series of volcanic-sedimentary rocks in Biepiao area of Liaoning Province. It is mainly composed of basic and intermediate-basic volcanic lava,pyroclasts and terrestrial sedimentary rocks. Ba...The Yixian Formation is a series of volcanic-sedimentary rocks in Biepiao area of Liaoning Province. It is mainly composed of basic and intermediate-basic volcanic lava,pyroclasts and terrestrial sedimentary rocks. Based on the regularity of volcanic activity,the Yixian Formation was divided by the present authors into four members in ascending order:the first member is of basal conglomerate,basic and intermediate-basic volcanic rocks; the second member is of lake phrase sedimentary rocks,or in another word,precious fossil-rich sedimentary beds; the third is of basic volcanic rocks; and the fourth is of upper conglomerate. Field mapping and comprehensive study also indicate that there are abundant vertebrate fossils (mainly of Psittacosaurus) in the first member of the Yixian Formation,and the Jehol Biota (including Sinosauropterxy,Confuciusorns sanctus,Archaefructus,etc.) is yielded in the second member of Yixian Formation. From west to east,the volcanic activity of Yixian Formation changed regularly from early to late,and from basic and intermediate-basic to acid (alkali).展开更多
Solvent evaporation method for preparation of nanomatrix has the disadvantages,such as residual organic solvent,environmental pollution,explosion-proofing and so on.To overcome these shortcomings,a series of fenofibra...Solvent evaporation method for preparation of nanomatrix has the disadvantages,such as residual organic solvent,environmental pollution,explosion-proofing and so on.To overcome these shortcomings,a series of fenofibrate nanomatrix drug delivery system(NDDS)consisting of nano-porous silica Sylysia■350(S350)and pH sensitive material Eudragit■L100-55(EL100-55)were prepared using hot-melt extrusion(HME),and their in vitro dissolution and in vivo bioavailability were compared.Finally,the formulation with the highest in vivo bioavailability was selected as the optimized formulation for DSC and PXRD characterization.The results showed that the optimized NDDS showed a higher bioavailability than the reference formulation,although there was crystalline form drug remaining in NDDS.The relative bioavailability of the optimized formulation was 157.1%compared with the commercial product Lipanthyl■.In addition,the relative bioavailability of the optimized formulation was 124.8%in comparison with the formulation prepared by solvent evaporation method,showing that the NDDS prepared by the HME method was effective in improving the bioavailability of fenofibrate.In conclusion,HME was a promising method to prepare NDDS.展开更多
基金Supported by the Research Fund of Gaziosmanpasa University (No.2003/42).
文摘Stearic acid (67.83℃) and myristic acid (52.32℃) have high melting temperatures that can limit their use as phase change material (PCM) in low temperature solar heating applications such as solar space and greenhouse heating in regard to climatic requirements. However, their melting temperatures can be adjusted to a suitable value by preparing a eutectic mixture of the myristic acid (MA) and the stearic acid (SA). In the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of myristic acid (MA) and stearic acid (SA) in the respective composition (by mass) of 64% and 36% forms a eutectic mixture having melting temperature of 44.13℃ and the latent heat of fusion of 182.4J·g-1. The thermal energy storage characteristics of the MA-SA eutectic mixture filled in the annulus of two concentric pipes were also experimentally established. The heat recovery rate and heat charging/discharging fractions were determined with respect to the change in the mass flow rate and the inlet temperature of heat transfer fluid. Based on the results obtained by DSC analysis and by the heat charg- ing/discharging processes of the PCM, it can be concluded that the MA-SA eutectic mixture is a potential material for low temperature thermal energy storage applications in terms of its thermo-physical and thermal characteristics.
基金This work was supported by the Major State Basic Research Program(No.G2000078503)Shandong Natural Science Foundation(No.Y2000E06).
文摘This article presents the evidence in support of the direct magma degassing as the principal mechanism of volatiles releasing into the hydrothermal fluids in the Okinawa Trough, as contrasted to the argument for the hydrothermal stripping of volatiles from the volcanic rocks.\ Laser Raman microprobe and stepped-heating techniques are employed to determine the compositions and contents of the volatiles in pumices in the middle Okinawa Trough. The results show that the volatiles are similar to the gases in the hydrothermal fluids and hydrothermal minerals in composition, the mean percent content of each component and variation trend. This indicates the direct influence of magma degassing on the hydrothermal fluids. In addition, the contents of volatiles in pumices are rather low and do not support the hydrothermal stripping as the main mechanism to enrich the fluids with gases. The results are consistent with the idea that the direct magma degassing is more important than hydrothermal stripping in supplying gases to the hydrothermal fluids in the Okinawa Trough.
文摘The Yixian Formation is a series of volcanic-sedimentary rocks in Biepiao area of Liaoning Province. It is mainly composed of basic and intermediate-basic volcanic lava,pyroclasts and terrestrial sedimentary rocks. Based on the regularity of volcanic activity,the Yixian Formation was divided by the present authors into four members in ascending order:the first member is of basal conglomerate,basic and intermediate-basic volcanic rocks; the second member is of lake phrase sedimentary rocks,or in another word,precious fossil-rich sedimentary beds; the third is of basic volcanic rocks; and the fourth is of upper conglomerate. Field mapping and comprehensive study also indicate that there are abundant vertebrate fossils (mainly of Psittacosaurus) in the first member of the Yixian Formation,and the Jehol Biota (including Sinosauropterxy,Confuciusorns sanctus,Archaefructus,etc.) is yielded in the second member of Yixian Formation. From west to east,the volcanic activity of Yixian Formation changed regularly from early to late,and from basic and intermediate-basic to acid (alkali).
基金National Basic Research Program of China(Grant No.2015CB932100)
文摘Solvent evaporation method for preparation of nanomatrix has the disadvantages,such as residual organic solvent,environmental pollution,explosion-proofing and so on.To overcome these shortcomings,a series of fenofibrate nanomatrix drug delivery system(NDDS)consisting of nano-porous silica Sylysia■350(S350)and pH sensitive material Eudragit■L100-55(EL100-55)were prepared using hot-melt extrusion(HME),and their in vitro dissolution and in vivo bioavailability were compared.Finally,the formulation with the highest in vivo bioavailability was selected as the optimized formulation for DSC and PXRD characterization.The results showed that the optimized NDDS showed a higher bioavailability than the reference formulation,although there was crystalline form drug remaining in NDDS.The relative bioavailability of the optimized formulation was 157.1%compared with the commercial product Lipanthyl■.In addition,the relative bioavailability of the optimized formulation was 124.8%in comparison with the formulation prepared by solvent evaporation method,showing that the NDDS prepared by the HME method was effective in improving the bioavailability of fenofibrate.In conclusion,HME was a promising method to prepare NDDS.
