Monte Carlo simulations are adopted to study the electron motion in the mixture of H2 and CH4 during diamond synthesis via Glow Plasma-assisted Chemical Vapor Deposition (GPCVD). The non-uniform electric field is used...Monte Carlo simulations are adopted to study the electron motion in the mixture of H2 and CH4 during diamond synthesis via Glow Plasma-assisted Chemical Vapor Deposition (GPCVD). The non-uniform electric field is used and the avalanche of electrons is taken into account in this simulation. The average energy distribution of electrons and the space distribution of effective species such as CH3, CH+3, CH+ and H at various gas pressures are given in this paper, and optimum experimental conditions are inferred from these results.展开更多
In this work,the solubility data and liquid-phase mass transfer coefficients of hydrogen(H2),methane(CH4)and their mixtures in vacuum gas oil(VGO)at temperatures(353.15-453.15 K)and pressures(1-7 MPa)were measured,whi...In this work,the solubility data and liquid-phase mass transfer coefficients of hydrogen(H2),methane(CH4)and their mixtures in vacuum gas oil(VGO)at temperatures(353.15-453.15 K)and pressures(1-7 MPa)were measured,which are necessary for catalytic cracking process simulation and design.The solubility of H2 and CH4 in VGO increases with the increase of pressure,but decreases with the increase of temperature.Henry’s constants of H2 and CH4 follow the relation of In H=-413.05/T+5.27 and In H=-990.67/T+5.87,respectively.The molar fractions of H2 and system pressures at different equilibrium time were measured to estimate the liquid-phase mass transfer coefficients.The results showed that with the increase of pressure,the liquid-phase mass transfer coefficients increase.Furthermore,the solubility of H2 and CH4 in VGO was predicted by the predictive COSMO-RS model,and the predicted values agree well with experimental data.In addition,the gas-liquid equilibrium(GLE)for H2+CH4+VGO system at different feeding gas ratios in volume fraction(i.e.,H285%+CH415%and H290%+CH410%)was measured.The selectivity of H2 to CH4 predicted by the COSMO-RS model agrees well with experimental data.This work provides the basic thermodynamic and dynamic data for fuel oil catalytic cracking processes.展开更多
<span style="font-family:Verdana;">Coordination compounds of 3-hydroxy-2-methyl-4</span><i><span style="font-family:Verdana;">H</span></i><span style="fo...<span style="font-family:Verdana;">Coordination compounds of 3-hydroxy-2-methyl-4</span><i><span style="font-family:Verdana;">H</span></i><span style="font-family:Verdana;">-pyran-4-one with </span><span style="font-family:Verdana;">iron(III), cobat(III) and chromium(III) were synthesized with M:L (1:2)</span><span style="font-family:Verdana;">. Mixed ligand coordination compounds of 3-hydroxy-2-methyl-4</span><i><span style="font-family:Verdana;">H</span></i><span style="font-family:Verdana;">-pyran-4-one and 1,2-diaminocyclohexane using the same metal ions were also synthesized </span><b><span style="font-family:Verdana;">M:L1</span></b><span style="font-family:Verdana;">:</span><b><span style="font-family:Verdana;">L2</span></b><span style="font-family:Verdana;"> (1:1:1) where </span><b><span style="font-family:Verdana;">L1</span></b><span style="font-family:Verdana;"> is 3-hydroxy-2-methyl-4</span><i><span style="font-family:Verdana;">H</span></i><span style="font-family:Verdana;">-pyran-4-one and </span><b><span style="font-family:Verdana;">L2</span></b><span style="font-family:Verdana;"> is 1,2-diaminocyclohexane. The coordination compounds obtained were characterized using electronic and infrared spectral analyses, magnetic susceptibility and percentage metal analysis. They were also evaluated for their cytotoxic and antioxidant activities. The result obtained suggested that octahedral geometry was obtained for all the compounds, as a result of additional two molecules of the solvent coordinated to the metal ions. Both the primary and secondary ligands coordinated in a bidentate fashion. The synthesized compounds exhibited moderate cytotoxicity, although none was as active as the standard. The cobalt(III) mixed ligand complex elicited the highest activity. The synthesized compounds all exhibited good to moderate antioxidant activity.</span>展开更多
Three kinds of activated carbons were prepared using coconut-shells as carbon precursors and characterized by XRD, FT-IR and texture property test. The results indicate that the prepared activated carbons were mainly ...Three kinds of activated carbons were prepared using coconut-shells as carbon precursors and characterized by XRD, FT-IR and texture property test. The results indicate that the prepared activated carbons were mainly amorphous and only a few impurity groups were adsorbed on their surfaces. The texture property test reveals that the activated carbons displayed different texture properties, especially the micropore size distribution. The adsorption capacities of the activated carbons were investigated by adsorbing CH4, CO2, N2 and O2 at 25 ?C in the pressure range of 0-200 kPa. The results reveal that all the activated carbons had high CO2 adsorption capacity, one of which had the highest CO2 adsorption value of 2.55 mmol/g at 200 kPa. And the highest adsorption capacity for CH4 of the activated carbons can reach 1.93 mmol/g at 200 kPa. In the pressure range of 0-200 kPa, the adsorption capacities for N2 and O2 were increased linearly with the change of pressure and K-AC is an excellent adsorbent towards the adsorption separation of greenhouse gases.展开更多
在带有输送煤样的管式反应器上进行了霍林河褐煤加压快速氢解实验,分析了H2对煤/半焦的化学键断裂和对CH4生成规律的影响。在加压快速氢解条件下,CH4产率随着热解温度升高、压力的增大而增大;在50%H2气氛下,操作压力为1.0 M Pa、温度为...在带有输送煤样的管式反应器上进行了霍林河褐煤加压快速氢解实验,分析了H2对煤/半焦的化学键断裂和对CH4生成规律的影响。在加压快速氢解条件下,CH4产率随着热解温度升高、压力的增大而增大;在50%H2气氛下,操作压力为1.0 M Pa、温度为900℃时,CH4产率为8.08%,达到最大,较N2气氛下的提高了72.5%。H2或H·自由基诱发了芳环的开裂、侧链、脂肪链和醚键的断裂,促进了煤热解。CH4产率的增加主要是由于外部供H的结果;热解温度低于700℃时,H2对煤结构中活性基团的作用促进了煤热解,导致了CH4产率的增加;而热解温度高于700℃后,煤/半焦加氢气化促进了CH4产率的增加。展开更多
The vapor-liquid equilibrium(VLE) properties for the binary and ternary mixtures of CH4,C2H4 and isoC4H10 are of great importance in the recovery of ethylene from mixture containing CH4 and C2H4 with iso-C4H10 as solv...The vapor-liquid equilibrium(VLE) properties for the binary and ternary mixtures of CH4,C2H4 and isoC4H10 are of great importance in the recovery of ethylene from mixture containing CH4 and C2H4 with iso-C4H10 as solvent.Hence,Gibbs ensemble Monte Carlo(GEMC) simulations were used to estimate vapor-liquid equilibrium for the binary and ternary mixtures of CH4,C2H4 and iso-C4H10 with the united atom potential NERD model.The selected simulation conditions are based on the experiment in the literature.The results of this work were shown to be in satisfactory agreement with available experimental data and predictions of Peng-Robinson equation of state.The structure of simulated liquid phase is also characterized by radial distribution function(RDF),which contributes to further understanding of the VLE curve of these systems.RDF is not sensitive to the pressure and temperature range.With the increase of pressure or the decrease of temperature,the molecules tend to gather together.展开更多
A novel three dimensional fluorinated gallium phosphate has been hydrothermally synthesized by using diethylenetriamine as an organic structure directing agent. X ray single crystal structure analysis indicates this c...A novel three dimensional fluorinated gallium phosphate has been hydrothermally synthesized by using diethylenetriamine as an organic structure directing agent. X ray single crystal structure analysis indicates this compound crystallizes in the orthorhombic space group Pbca, a =1.605 6(7) nm, b = 1 011 4 (4) nm, c =1.854 6(5) nm, V =3.011 6(19) nm 3, Z =4. The three dimensional framework based on linkage of corner sharing polyhedron PO 4, GaO 4F and GaO 4F 2 delimit ten ring channels along b axis in which the triply protonated amines are located serving as charge compensating guests and supporters.展开更多
Experiments performed on the grwth of mixed crystals of rare earth tartrates (Y1-xSmx)2 (C4H4O6)3.zH2O (0≤x≤1) from silica gels at 35~40℃ and 25~30℃ employing single-diffusion technique. are discussed. The crysta...Experiments performed on the grwth of mixed crystals of rare earth tartrates (Y1-xSmx)2 (C4H4O6)3.zH2O (0≤x≤1) from silica gels at 35~40℃ and 25~30℃ employing single-diffusion technique. are discussed. The crystals maintain spherulitic morphology, irrespective of the value of x, concentration of upper and lower reactants, gel pH, gel age and gel temperature. Formation Of Liesegang rings in this system is a temperature dependent phenomenon. It is shown that with the increase of the value of x the system passes from Liesegangring phenomenon to singlezone phenomenon. Operative mechanism of crystallization in the higher (35~40℃) and lower temperature ranges (25~30℃) is explained. Seeded growth experiments indicate the possibility of increasing the size of the spherulites in the gel medium展开更多
基金This work was supported by Doctor Foundation of Hebei Education Committee Hebei Natural Science Foundation(599091 ) of China
文摘Monte Carlo simulations are adopted to study the electron motion in the mixture of H2 and CH4 during diamond synthesis via Glow Plasma-assisted Chemical Vapor Deposition (GPCVD). The non-uniform electric field is used and the avalanche of electrons is taken into account in this simulation. The average energy distribution of electrons and the space distribution of effective species such as CH3, CH+3, CH+ and H at various gas pressures are given in this paper, and optimum experimental conditions are inferred from these results.
基金Supported by the National Natural Science Foundation of China(U1862103).
文摘In this work,the solubility data and liquid-phase mass transfer coefficients of hydrogen(H2),methane(CH4)and their mixtures in vacuum gas oil(VGO)at temperatures(353.15-453.15 K)and pressures(1-7 MPa)were measured,which are necessary for catalytic cracking process simulation and design.The solubility of H2 and CH4 in VGO increases with the increase of pressure,but decreases with the increase of temperature.Henry’s constants of H2 and CH4 follow the relation of In H=-413.05/T+5.27 and In H=-990.67/T+5.87,respectively.The molar fractions of H2 and system pressures at different equilibrium time were measured to estimate the liquid-phase mass transfer coefficients.The results showed that with the increase of pressure,the liquid-phase mass transfer coefficients increase.Furthermore,the solubility of H2 and CH4 in VGO was predicted by the predictive COSMO-RS model,and the predicted values agree well with experimental data.In addition,the gas-liquid equilibrium(GLE)for H2+CH4+VGO system at different feeding gas ratios in volume fraction(i.e.,H285%+CH415%and H290%+CH410%)was measured.The selectivity of H2 to CH4 predicted by the COSMO-RS model agrees well with experimental data.This work provides the basic thermodynamic and dynamic data for fuel oil catalytic cracking processes.
文摘<span style="font-family:Verdana;">Coordination compounds of 3-hydroxy-2-methyl-4</span><i><span style="font-family:Verdana;">H</span></i><span style="font-family:Verdana;">-pyran-4-one with </span><span style="font-family:Verdana;">iron(III), cobat(III) and chromium(III) were synthesized with M:L (1:2)</span><span style="font-family:Verdana;">. Mixed ligand coordination compounds of 3-hydroxy-2-methyl-4</span><i><span style="font-family:Verdana;">H</span></i><span style="font-family:Verdana;">-pyran-4-one and 1,2-diaminocyclohexane using the same metal ions were also synthesized </span><b><span style="font-family:Verdana;">M:L1</span></b><span style="font-family:Verdana;">:</span><b><span style="font-family:Verdana;">L2</span></b><span style="font-family:Verdana;"> (1:1:1) where </span><b><span style="font-family:Verdana;">L1</span></b><span style="font-family:Verdana;"> is 3-hydroxy-2-methyl-4</span><i><span style="font-family:Verdana;">H</span></i><span style="font-family:Verdana;">-pyran-4-one and </span><b><span style="font-family:Verdana;">L2</span></b><span style="font-family:Verdana;"> is 1,2-diaminocyclohexane. The coordination compounds obtained were characterized using electronic and infrared spectral analyses, magnetic susceptibility and percentage metal analysis. They were also evaluated for their cytotoxic and antioxidant activities. The result obtained suggested that octahedral geometry was obtained for all the compounds, as a result of additional two molecules of the solvent coordinated to the metal ions. Both the primary and secondary ligands coordinated in a bidentate fashion. The synthesized compounds exhibited moderate cytotoxicity, although none was as active as the standard. The cobalt(III) mixed ligand complex elicited the highest activity. The synthesized compounds all exhibited good to moderate antioxidant activity.</span>
基金supported by the National Natural Science Foundation of China(Grant 20773090)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant 200806100009)
文摘Three kinds of activated carbons were prepared using coconut-shells as carbon precursors and characterized by XRD, FT-IR and texture property test. The results indicate that the prepared activated carbons were mainly amorphous and only a few impurity groups were adsorbed on their surfaces. The texture property test reveals that the activated carbons displayed different texture properties, especially the micropore size distribution. The adsorption capacities of the activated carbons were investigated by adsorbing CH4, CO2, N2 and O2 at 25 ?C in the pressure range of 0-200 kPa. The results reveal that all the activated carbons had high CO2 adsorption capacity, one of which had the highest CO2 adsorption value of 2.55 mmol/g at 200 kPa. And the highest adsorption capacity for CH4 of the activated carbons can reach 1.93 mmol/g at 200 kPa. In the pressure range of 0-200 kPa, the adsorption capacities for N2 and O2 were increased linearly with the change of pressure and K-AC is an excellent adsorbent towards the adsorption separation of greenhouse gases.
文摘在带有输送煤样的管式反应器上进行了霍林河褐煤加压快速氢解实验,分析了H2对煤/半焦的化学键断裂和对CH4生成规律的影响。在加压快速氢解条件下,CH4产率随着热解温度升高、压力的增大而增大;在50%H2气氛下,操作压力为1.0 M Pa、温度为900℃时,CH4产率为8.08%,达到最大,较N2气氛下的提高了72.5%。H2或H·自由基诱发了芳环的开裂、侧链、脂肪链和醚键的断裂,促进了煤热解。CH4产率的增加主要是由于外部供H的结果;热解温度低于700℃时,H2对煤结构中活性基团的作用促进了煤热解,导致了CH4产率的增加;而热解温度高于700℃后,煤/半焦加氢气化促进了CH4产率的增加。
基金Supported by the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT0936)National Basic Research Program of China("973"Program,No.2009CB219905 and No.2009CB219907)
文摘The vapor-liquid equilibrium(VLE) properties for the binary and ternary mixtures of CH4,C2H4 and isoC4H10 are of great importance in the recovery of ethylene from mixture containing CH4 and C2H4 with iso-C4H10 as solvent.Hence,Gibbs ensemble Monte Carlo(GEMC) simulations were used to estimate vapor-liquid equilibrium for the binary and ternary mixtures of CH4,C2H4 and iso-C4H10 with the united atom potential NERD model.The selected simulation conditions are based on the experiment in the literature.The results of this work were shown to be in satisfactory agreement with available experimental data and predictions of Peng-Robinson equation of state.The structure of simulated liquid phase is also characterized by radial distribution function(RDF),which contributes to further understanding of the VLE curve of these systems.RDF is not sensitive to the pressure and temperature range.With the increase of pressure or the decrease of temperature,the molecules tend to gather together.
文摘A novel three dimensional fluorinated gallium phosphate has been hydrothermally synthesized by using diethylenetriamine as an organic structure directing agent. X ray single crystal structure analysis indicates this compound crystallizes in the orthorhombic space group Pbca, a =1.605 6(7) nm, b = 1 011 4 (4) nm, c =1.854 6(5) nm, V =3.011 6(19) nm 3, Z =4. The three dimensional framework based on linkage of corner sharing polyhedron PO 4, GaO 4F and GaO 4F 2 delimit ten ring channels along b axis in which the triply protonated amines are located serving as charge compensating guests and supporters.
文摘Experiments performed on the grwth of mixed crystals of rare earth tartrates (Y1-xSmx)2 (C4H4O6)3.zH2O (0≤x≤1) from silica gels at 35~40℃ and 25~30℃ employing single-diffusion technique. are discussed. The crystals maintain spherulitic morphology, irrespective of the value of x, concentration of upper and lower reactants, gel pH, gel age and gel temperature. Formation Of Liesegang rings in this system is a temperature dependent phenomenon. It is shown that with the increase of the value of x the system passes from Liesegangring phenomenon to singlezone phenomenon. Operative mechanism of crystallization in the higher (35~40℃) and lower temperature ranges (25~30℃) is explained. Seeded growth experiments indicate the possibility of increasing the size of the spherulites in the gel medium