To analyze static pressure between back plate and cylinder in an A186 carding machine,a fluid model is established. The model takes into account static pressure of airflow near back plate with the numerical simulation...To analyze static pressure between back plate and cylinder in an A186 carding machine,a fluid model is established. The model takes into account static pressure of airflow near back plate with the numerical simulation method of Computational Fluid Dynamics (CFD) in FLUENT software. The result of the simulation in the model shows that static pressure in this area quickly increases to its maximum then rapidly decreases to a lower fixed value from inlet to outlet along a zone between back plate and cylinder. Both rotating speeds of the cylinder and the taker-in affect static pressure from the inlet to the outlet,of which the cylinder rotating speed has more influence than that of taker-in. Numerical simulations reveal that static pressure on surface of back plate are in good agreement with the former result of experimental analysis.展开更多
Taiwan government has been executing the educational reform programs for more than two decades. However, the so-called between-class ability grouping which is prohibited by Taiwan government is still found in many pla...Taiwan government has been executing the educational reform programs for more than two decades. However, the so-called between-class ability grouping which is prohibited by Taiwan government is still found in many places; and Taiwan＇s cram schools are even more popular and diversified than before. The authors argue that, in addition to individual＇s socio-economic background, regional characteristics and school attributes also play important roles. Bringing these two factors back in, the causal relationships among ability grouping, cram schooling, and student academic achievement can be analyzed more accurately. Using data from Taiwan Education Panel Survey, the authors＇ empirical results show that, first of all, in more urbanized area, between-class ability grouping is less popular but cram school participation is wider spread these years. Secondly, the effects of family backgrounds on students＇ cram school participation are not as critical as they were before. Thirdly, between-class ability grouping and students＇ performance are positively associated but the internal mechanism still needs further investigation.展开更多
With unique physical and chemical properties, aqueous solutions in the mantle may play important roles for a number of geochemical and geodynamical processes. However, since experimental data available are very limite...With unique physical and chemical properties, aqueous solutions in the mantle may play important roles for a number of geochemical and geodynamical processes. However, since experimental data available are very limited, people still know little about the aqueous solutions and their interactions with surrounding rocks and melts. From the perspective of thermodynamics, equation of state(EOS) is the key to push forward the modeling of aqueous solutions. Nevertheless, up to now accurate EOSs suitable for the mantle conditions are still in shortage. With discussions over several recognized EOSs, we summarize several ways to enhance the predictability of EOS: utilizing high quality data from molecular simulations, choosing functions with sound physical background, and improving the regression procedures for the empirical parameters. In the meantime, we find that the ion-bearing systems are still the focus of challenges in this area. New developments of experiments and computer simulations effectively deal with these challenges and in-depth understandings of aqueous solutions in the mantle are expected in the near future.展开更多
Multiple methods were applied to study the deformation characteristics of hornblende in Archean plagioamphibolite mylonite from the Western Hills(Beijing),including optical microscopy(OM),electron backscatter diffract...Multiple methods were applied to study the deformation characteristics of hornblende in Archean plagioamphibolite mylonite from the Western Hills(Beijing),including optical microscopy(OM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),and electron probe microanalysis(EPMA).The hornblendes are σ and δ type porphyroclasts with the new-born needle shaped grains as their tails.The analysis of lattice preferred orientation(LPO) of both the porphyroclasts and the new-born grains shows that the main slip system of the deformed hornblende is(100)<001>,suggesting that the fabric characteristics of new-born grains inherit that of porphyroclasts.Sub-microstructures show the porphyroclast core is dominated by dislocation tangle,little or no dislocations in the new-born grains,and the subgrains confined by dislocations in the transition zone between porphyroclasts and new-born grains.By using plagioclase-hornblende geothermometry and hornblende geobarometry,the estimated temperature and pressure of porphyroclasts are 675.3-702.9℃ and 0.29-0.41 GPa and those of new-born grains are 614.1-679.0℃ and 0.11-0.31 GPa.The bulging recrystallization is summarized as deformation mechanisms of hornblende by the discussions of the microstructures,EBSD fabric,sub-microstructures,and the deformed temperature and pressure.展开更多
基金Project of Liaoning Provincial Science and Technology Department, China(No.200322026)
文摘To analyze static pressure between back plate and cylinder in an A186 carding machine,a fluid model is established. The model takes into account static pressure of airflow near back plate with the numerical simulation method of Computational Fluid Dynamics (CFD) in FLUENT software. The result of the simulation in the model shows that static pressure in this area quickly increases to its maximum then rapidly decreases to a lower fixed value from inlet to outlet along a zone between back plate and cylinder. Both rotating speeds of the cylinder and the taker-in affect static pressure from the inlet to the outlet,of which the cylinder rotating speed has more influence than that of taker-in. Numerical simulations reveal that static pressure on surface of back plate are in good agreement with the former result of experimental analysis.
文摘Taiwan government has been executing the educational reform programs for more than two decades. However, the so-called between-class ability grouping which is prohibited by Taiwan government is still found in many places; and Taiwan＇s cram schools are even more popular and diversified than before. The authors argue that, in addition to individual＇s socio-economic background, regional characteristics and school attributes also play important roles. Bringing these two factors back in, the causal relationships among ability grouping, cram schooling, and student academic achievement can be analyzed more accurately. Using data from Taiwan Education Panel Survey, the authors＇ empirical results show that, first of all, in more urbanized area, between-class ability grouping is less popular but cram school participation is wider spread these years. Secondly, the effects of family backgrounds on students＇ cram school participation are not as critical as they were before. Thirdly, between-class ability grouping and students＇ performance are positively associated but the internal mechanism still needs further investigation.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41590620 & 41473060)
文摘With unique physical and chemical properties, aqueous solutions in the mantle may play important roles for a number of geochemical and geodynamical processes. However, since experimental data available are very limited, people still know little about the aqueous solutions and their interactions with surrounding rocks and melts. From the perspective of thermodynamics, equation of state(EOS) is the key to push forward the modeling of aqueous solutions. Nevertheless, up to now accurate EOSs suitable for the mantle conditions are still in shortage. With discussions over several recognized EOSs, we summarize several ways to enhance the predictability of EOS: utilizing high quality data from molecular simulations, choosing functions with sound physical background, and improving the regression procedures for the empirical parameters. In the meantime, we find that the ion-bearing systems are still the focus of challenges in this area. New developments of experiments and computer simulations effectively deal with these challenges and in-depth understandings of aqueous solutions in the mantle are expected in the near future.
基金supported by the National Natural Science Foundation of China (Grant No.40772133)
文摘Multiple methods were applied to study the deformation characteristics of hornblende in Archean plagioamphibolite mylonite from the Western Hills(Beijing),including optical microscopy(OM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),and electron probe microanalysis(EPMA).The hornblendes are σ and δ type porphyroclasts with the new-born needle shaped grains as their tails.The analysis of lattice preferred orientation(LPO) of both the porphyroclasts and the new-born grains shows that the main slip system of the deformed hornblende is(100)<001>,suggesting that the fabric characteristics of new-born grains inherit that of porphyroclasts.Sub-microstructures show the porphyroclast core is dominated by dislocation tangle,little or no dislocations in the new-born grains,and the subgrains confined by dislocations in the transition zone between porphyroclasts and new-born grains.By using plagioclase-hornblende geothermometry and hornblende geobarometry,the estimated temperature and pressure of porphyroclasts are 675.3-702.9℃ and 0.29-0.41 GPa and those of new-born grains are 614.1-679.0℃ and 0.11-0.31 GPa.The bulging recrystallization is summarized as deformation mechanisms of hornblende by the discussions of the microstructures,EBSD fabric,sub-microstructures,and the deformed temperature and pressure.
