Pitch and TiB2/C green composite cathode material were respectively analyzed with simultaneous DSC-TGA, and effects of three baking processes of TiB2/C composite cathode material, i.e. K25, K5 and M5, on properties of...Pitch and TiB2/C green composite cathode material were respectively analyzed with simultaneous DSC-TGA, and effects of three baking processes of TiB2/C composite cathode material, i.e. K25, K5 and M5, on properties of TiB2/C composite cathode material were investigated. The results show that thermogravimetrie behavior of pitch and TiB2/C green composite cathode is similar, and appears the largest mass loss rate in the temperature range from 200 to 600 ℃. The bulk density variation of sample K5 before and after baking is the largest （11.9%）, that of sample K25 is the second, and that of sample M5 is the smallest （6.7%）. The crushing strength of sample M5 is the biggest （51.2 MPa）, that of sample K2.5 is the next, and that of sample K5 is the smallest （32.8 MPa）. But, the orders of the electrical resistivity and electrolysis expansion of samples are just opposite with the order of crushing strength. The heating rate has a great impact on the microstructure of sample. The faster the heating rate is, the bigger the pore size and porosity of sample are. Compared with the heating rate between 200 and 600℃ of samples K25 and K5, that of sample M5 is slower and suitable for baking process of TiB2/C composite cathode material.展开更多
Thick SU8 microstructures with high aspect ratio and good side wall quality were fabricated by ultraviolet （UV） lithography, and the processing parameters were comprehensively studied. It proves that the adhesion of...Thick SU8 microstructures with high aspect ratio and good side wall quality were fabricated by ultraviolet （UV） lithography, and the processing parameters were comprehensively studied. It proves that the adhesion of SU8 on silicon （Si） substrates is influenced by Si-OH on the surface, and can be improved by the HF treatment. Cracks and de- lamination are caused by large internal stress during fabrication process, and are significantly influenced by soft bake and post-exposure bake processes. The internal stress is reduced by a low post-exposure bake exposure tem- perature of 85 ℃ for 40 rain. A three-step soft bake enhances the reflowing ofSU8 photoresist, and results in uni- form surface and less air bubbles. The vertical side wall is obtained with the optimized exposure dose of 800 mJ/cm2 for the thickness of 160 μm. Using the optimized fabrication process combined with a proper structure design, dense SU8 micro pillars are achieved with the aspect ratio of 10 and the taper angle of 89.86°. Finally, some possible ap- plications of SU8 in micro-electromechanical system （MEMS） device are developed and demonstrated.展开更多
How to use the oven to bake delicious food is the most concerned problem of the designers and users of the oven.For this intent,this paper analyzed the heat distribution in the oven based on the basic operation princi...How to use the oven to bake delicious food is the most concerned problem of the designers and users of the oven.For this intent,this paper analyzed the heat distribution in the oven based on the basic operation principles and proceeded the data simulation of the temperature distribution on the rack section.Constructing the differential equation model of the temperature distribution changes in the pan when the oven works based on the heat radiation and heat transmission,based on the idea of utilizing cellular automation to simulate heat transfer process,used ANSYS software to proceed the numerical simulation analysis to the rectangular,round-cornered rectangular,elliptical and circular pans and giving out the instantaneous temperature distribution of the corresponding shapes of the pans.The temperature distribution of the rectangular and circular pans proves that the product gets overcooked easily at the corners and edges of rectangular pans but not of a round pan.展开更多
基金Project (2005CB623703) supported by the Major State Basic Research and Development Program of ChinaProject (2008AA030502) supported by the National High-Tech Research and Development Program of China
文摘Pitch and TiB2/C green composite cathode material were respectively analyzed with simultaneous DSC-TGA, and effects of three baking processes of TiB2/C composite cathode material, i.e. K25, K5 and M5, on properties of TiB2/C composite cathode material were investigated. The results show that thermogravimetrie behavior of pitch and TiB2/C green composite cathode is similar, and appears the largest mass loss rate in the temperature range from 200 to 600 ℃. The bulk density variation of sample K5 before and after baking is the largest （11.9%）, that of sample K25 is the second, and that of sample M5 is the smallest （6.7%）. The crushing strength of sample M5 is the biggest （51.2 MPa）, that of sample K2.5 is the next, and that of sample K5 is the smallest （32.8 MPa）. But, the orders of the electrical resistivity and electrolysis expansion of samples are just opposite with the order of crushing strength. The heating rate has a great impact on the microstructure of sample. The faster the heating rate is, the bigger the pore size and porosity of sample are. Compared with the heating rate between 200 and 600℃ of samples K25 and K5, that of sample M5 is slower and suitable for baking process of TiB2/C composite cathode material.
基金supported by the National High Technology Research and Development Program(No.2015AA042603)the Fundamental Research Funds for the Central Universities in China(Nos.106112014CDJZR160001 and 106112015CDJXY120002)
文摘Thick SU8 microstructures with high aspect ratio and good side wall quality were fabricated by ultraviolet （UV） lithography, and the processing parameters were comprehensively studied. It proves that the adhesion of SU8 on silicon （Si） substrates is influenced by Si-OH on the surface, and can be improved by the HF treatment. Cracks and de- lamination are caused by large internal stress during fabrication process, and are significantly influenced by soft bake and post-exposure bake processes. The internal stress is reduced by a low post-exposure bake exposure tem- perature of 85 ℃ for 40 rain. A three-step soft bake enhances the reflowing ofSU8 photoresist, and results in uni- form surface and less air bubbles. The vertical side wall is obtained with the optimized exposure dose of 800 mJ/cm2 for the thickness of 160 μm. Using the optimized fabrication process combined with a proper structure design, dense SU8 micro pillars are achieved with the aspect ratio of 10 and the taper angle of 89.86°. Finally, some possible ap- plications of SU8 in micro-electromechanical system （MEMS） device are developed and demonstrated.
文摘How to use the oven to bake delicious food is the most concerned problem of the designers and users of the oven.For this intent,this paper analyzed the heat distribution in the oven based on the basic operation principles and proceeded the data simulation of the temperature distribution on the rack section.Constructing the differential equation model of the temperature distribution changes in the pan when the oven works based on the heat radiation and heat transmission,based on the idea of utilizing cellular automation to simulate heat transfer process,used ANSYS software to proceed the numerical simulation analysis to the rectangular,round-cornered rectangular,elliptical and circular pans and giving out the instantaneous temperature distribution of the corresponding shapes of the pans.The temperature distribution of the rectangular and circular pans proves that the product gets overcooked easily at the corners and edges of rectangular pans but not of a round pan.
