The fossil shells on the sedimentary rocks were collected from The Historical Park,Ban Sap Noi Geopark,Phetchabun Province,Thailand.However,the fossils remained in this area were investigated on the characteristic spe...The fossil shells on the sedimentary rocks were collected from The Historical Park,Ban Sap Noi Geopark,Phetchabun Province,Thailand.However,the fossils remained in this area were investigated on the characteristic species only in geological studies with taxonomy for fossil age predicting.To fill up the gap of these studies,the material characterization techniques were used to study the chemical composition and structure of fossil shells I,II and III.The results clearly showed that the morphologies of all fossil shells were Brachiopod fossils with different species.The functional group and elemental composition of all fossil shells showed that the high content of calcium carbonate was a major composition.In addition,the high content of quartz indicated the silica precipitation phenomenon in all fossil shells.The element composition of cross-sectional morphology and energy dispersive spectroscope (EDS mapping) were used to confirm the presence of Si element in each zone of fossil shells.The crystal structures of all fossil shells were investigated and indicated that the calcium carbonate compound was a calcite phase and silicon dioxide compound was a quartz phase.Moreover,the crystal structure of quartz phase was used to calculate the crystallinity index.The crystallinity index values in all fossil shells indicated a well-crystallized quartz.The age of fossil shells was estimated and found to be brachiopod fossil in carboniferous period with the age of about 359.2 to 299.0 million years.展开更多
The duck eggshell waste was developed to the novel desiccant that is friendly to human and environment.The calcium oxide(Ca O)and calcium chloride(CaCl_(2))as the calcium-based desiccants were prepared from eggshell w...The duck eggshell waste was developed to the novel desiccant that is friendly to human and environment.The calcium oxide(Ca O)and calcium chloride(CaCl_(2))as the calcium-based desiccants were prepared from eggshell waste.The Ca O desiccant derived from the eggshell waste sintering at 1300℃,while the CaCl_(2)desiccant was extracted from eggshell waste with the hydrochloric(HCl)solution at difierent concentrations from 5 to 30 wt%.The yield percentage of CaCl_(2)desiccant increased with increasing the HCl concentration to 25 wt%.The humidity adsorption behavior were investigated in the range of 75%-5%relative humidity.The results show the CaCl_(2)desiccant has the highest hydration rate.The porous host from the kaolin was sintered at different temperatures from 200 to 1000℃and incorporated with 30%w/v concentrations of CaCl_(2).The physical properties and the humid-adsorption capacity of all porous host conditions were investigated.The porous host at sintering temperature 800℃has the highest specific surface area.Moreover,the porous host at sintering temperature 800℃with the 30%w/v concentration of CaCl_(2)desiccant has the highest humid-adsorption capacity.展开更多
The filler metals of AgAlTi and AgAlTiCo were selected for the vacuum brazing of TiAl alloy and 42CrMo under different processing parameters. The results show that for both filler metals, the highest tensile strength ...The filler metals of AgAlTi and AgAlTiCo were selected for the vacuum brazing of TiAl alloy and 42CrMo under different processing parameters. The results show that for both filler metals, the highest tensile strength of joint can be achieved at 950℃, 15min, and with the addition of Co the joint strength becomes higher. By the comparison of the microstructure of joints, the joint interface is the main factor that influences the joint strength.展开更多
At first, a series of finite element method （FEM） simulation tests were used to find the critical forming conditions of hot-galvanized sheet steel during the rectangular box drawing processing when constant blank ho...At first, a series of finite element method （FEM） simulation tests were used to find the critical forming conditions of hot-galvanized sheet steel during the rectangular box drawing processing when constant blank holder forces were applied. According the test results, the reasonable alteration scope of initial variable blank holder force （VBHF） was as 1.9-2.3 T. Then, based on the test productions of blank holder force, 12 typical VBHF curves were applied to perform the simulation tests by the simulation software of DYNAFORM. The simulation test results showed that VBHF had great effects on drawing formability of hot-galvanized sheet steel during the rectangular box drawing. However, the different VBHF curves were applied to control the whole drawing and it would get great different effects. At the same tine, the VBHF had great effects on the maximum thick thinning ratio, but had little effect on the maximum thick incrassation ratio. So, reasonable application of the VBHF would greatly decrease the fractures. When the VBHF profile is taken as curve L, the best effect of drawing formability could be obtained. When curve I is used, contrary effect could be gotten. The other types of curves would cause effects between above two types of VBHF curves. Finally, the actual tests were applied to check the validity of the FEM simulation tests. The results show that the FEM simulation tests are good ways for predicting and optimizing the VBHF.展开更多
In continuous casting rolling process, the deformed body is different from the hot rolling strip. The metal in casting rolling zone is first assumed to be viscous fluid and the mathematical model of casting rolling fo...In continuous casting rolling process, the deformed body is different from the hot rolling strip. The metal in casting rolling zone is first assumed to be viscous fluid and the mathematical model of casting rolling force is established, then the calculating formula for casting rolling torque is derived. In addition, considering the effects of deforming cone and appendant torque of rotary junctions sealing ring, the calculating model which accords with casting rolling condition is found out. Theoretical formula is proved by experiment.展开更多
With a geometrical model of porous material, a 3D finite-element analysis on the rolling process of spring steel60Si2Mn in the semi-solid state is carried out using software MARC. In terms of flat and groove rolling c...With a geometrical model of porous material, a 3D finite-element analysis on the rolling process of spring steel60Si2Mn in the semi-solid state is carried out using software MARC. In terms of flat and groove rolling conditions,stress field and strain field are studied. The simulation results show that the rigid-viscoplastic model can accuratelydescribe the semi-solid metal rolling process. Semi-solid slurry has the characteristics of low flow stress and goodfluidity. During groove rolling, distribution of stress and strain on the cross-section of deformation zone is moreuniform than that during flat rolling. The results of simulation are in good agreement with the experiment data, andshow that semi-solid material fits for groove rolling.展开更多
In this work, the possibility of enhanced activity during the hydrodesulfurization of dibenzothiophene over certain nano-MoS<sub>2</sub> catalyst due to the presence of H<sub>2</sub>S was exami...In this work, the possibility of enhanced activity during the hydrodesulfurization of dibenzothiophene over certain nano-MoS<sub>2</sub> catalyst due to the presence of H<sub>2</sub>S was examined by focusing on the reaction kinetics. With H<sub>2</sub>S generated <i>in situ</i>, the overall reaction followed the autocatalytic rate law;while in the absence of H<sub>2</sub>S the kinetics indicated a pseudo-first-order reaction. H<sub>2</sub>S appears to modify the relative contributions of parallel hydrogenation and desulfurization reactions by drastically increasing the hydrogenation rate. Kinetic models were developed that describe the hydrodesulfurization reaction at various H<sub>2</sub>S concentrations, and the kinetic parameters and adsorption equilibrium constants associated with this process were estimated by fitting the experimental data. The results suggest that the promotion and/or inhibition of hydrodesulfurization by H<sub>2</sub>S likely result from the same overall reaction mechanism.展开更多
基金supported by the Science Achievement Scholarship of Thailand (SAST)the support of Office of Atom for Peace,Thailand and Thailand Institute of Nuclear Technology (a public organization) for providing facilities for some experiment in this work。
文摘The fossil shells on the sedimentary rocks were collected from The Historical Park,Ban Sap Noi Geopark,Phetchabun Province,Thailand.However,the fossils remained in this area were investigated on the characteristic species only in geological studies with taxonomy for fossil age predicting.To fill up the gap of these studies,the material characterization techniques were used to study the chemical composition and structure of fossil shells I,II and III.The results clearly showed that the morphologies of all fossil shells were Brachiopod fossils with different species.The functional group and elemental composition of all fossil shells showed that the high content of calcium carbonate was a major composition.In addition,the high content of quartz indicated the silica precipitation phenomenon in all fossil shells.The element composition of cross-sectional morphology and energy dispersive spectroscope (EDS mapping) were used to confirm the presence of Si element in each zone of fossil shells.The crystal structures of all fossil shells were investigated and indicated that the calcium carbonate compound was a calcite phase and silicon dioxide compound was a quartz phase.Moreover,the crystal structure of quartz phase was used to calculate the crystallinity index.The crystallinity index values in all fossil shells indicated a well-crystallized quartz.The age of fossil shells was estimated and found to be brachiopod fossil in carboniferous period with the age of about 359.2 to 299.0 million years.
基金the research professional development project under the Science Achievement Scholarship of Thailand(SAST)for education financial support。
文摘The duck eggshell waste was developed to the novel desiccant that is friendly to human and environment.The calcium oxide(Ca O)and calcium chloride(CaCl_(2))as the calcium-based desiccants were prepared from eggshell waste.The Ca O desiccant derived from the eggshell waste sintering at 1300℃,while the CaCl_(2)desiccant was extracted from eggshell waste with the hydrochloric(HCl)solution at difierent concentrations from 5 to 30 wt%.The yield percentage of CaCl_(2)desiccant increased with increasing the HCl concentration to 25 wt%.The humidity adsorption behavior were investigated in the range of 75%-5%relative humidity.The results show the CaCl_(2)desiccant has the highest hydration rate.The porous host from the kaolin was sintered at different temperatures from 200 to 1000℃and incorporated with 30%w/v concentrations of CaCl_(2).The physical properties and the humid-adsorption capacity of all porous host conditions were investigated.The porous host at sintering temperature 800℃has the highest specific surface area.Moreover,the porous host at sintering temperature 800℃with the 30%w/v concentration of CaCl_(2)desiccant has the highest humid-adsorption capacity.
文摘The filler metals of AgAlTi and AgAlTiCo were selected for the vacuum brazing of TiAl alloy and 42CrMo under different processing parameters. The results show that for both filler metals, the highest tensile strength of joint can be achieved at 950℃, 15min, and with the addition of Co the joint strength becomes higher. By the comparison of the microstructure of joints, the joint interface is the main factor that influences the joint strength.
文摘At first, a series of finite element method （FEM） simulation tests were used to find the critical forming conditions of hot-galvanized sheet steel during the rectangular box drawing processing when constant blank holder forces were applied. According the test results, the reasonable alteration scope of initial variable blank holder force （VBHF） was as 1.9-2.3 T. Then, based on the test productions of blank holder force, 12 typical VBHF curves were applied to perform the simulation tests by the simulation software of DYNAFORM. The simulation test results showed that VBHF had great effects on drawing formability of hot-galvanized sheet steel during the rectangular box drawing. However, the different VBHF curves were applied to control the whole drawing and it would get great different effects. At the same tine, the VBHF had great effects on the maximum thick thinning ratio, but had little effect on the maximum thick incrassation ratio. So, reasonable application of the VBHF would greatly decrease the fractures. When the VBHF profile is taken as curve L, the best effect of drawing formability could be obtained. When curve I is used, contrary effect could be gotten. The other types of curves would cause effects between above two types of VBHF curves. Finally, the actual tests were applied to check the validity of the FEM simulation tests. The results show that the FEM simulation tests are good ways for predicting and optimizing the VBHF.
文摘In continuous casting rolling process, the deformed body is different from the hot rolling strip. The metal in casting rolling zone is first assumed to be viscous fluid and the mathematical model of casting rolling force is established, then the calculating formula for casting rolling torque is derived. In addition, considering the effects of deforming cone and appendant torque of rotary junctions sealing ring, the calculating model which accords with casting rolling condition is found out. Theoretical formula is proved by experiment.
基金This project is supported by the National Natural Science Foundation of China under grant No. 50174003 and No. 59995440.
文摘With a geometrical model of porous material, a 3D finite-element analysis on the rolling process of spring steel60Si2Mn in the semi-solid state is carried out using software MARC. In terms of flat and groove rolling conditions,stress field and strain field are studied. The simulation results show that the rigid-viscoplastic model can accuratelydescribe the semi-solid metal rolling process. Semi-solid slurry has the characteristics of low flow stress and goodfluidity. During groove rolling, distribution of stress and strain on the cross-section of deformation zone is moreuniform than that during flat rolling. The results of simulation are in good agreement with the experiment data, andshow that semi-solid material fits for groove rolling.
文摘In this work, the possibility of enhanced activity during the hydrodesulfurization of dibenzothiophene over certain nano-MoS<sub>2</sub> catalyst due to the presence of H<sub>2</sub>S was examined by focusing on the reaction kinetics. With H<sub>2</sub>S generated <i>in situ</i>, the overall reaction followed the autocatalytic rate law;while in the absence of H<sub>2</sub>S the kinetics indicated a pseudo-first-order reaction. H<sub>2</sub>S appears to modify the relative contributions of parallel hydrogenation and desulfurization reactions by drastically increasing the hydrogenation rate. Kinetic models were developed that describe the hydrodesulfurization reaction at various H<sub>2</sub>S concentrations, and the kinetic parameters and adsorption equilibrium constants associated with this process were estimated by fitting the experimental data. The results suggest that the promotion and/or inhibition of hydrodesulfurization by H<sub>2</sub>S likely result from the same overall reaction mechanism.
