Nobel metallic Pt/ZSM-22 and Pt/ZSM-23 catalysts were prepared for hydroisomerization of normal dodecane and hydrodewaxing of heavy waxy lube base oil.The hydroisomerization performance of n-dodecane indicated that th...Nobel metallic Pt/ZSM-22 and Pt/ZSM-23 catalysts were prepared for hydroisomerization of normal dodecane and hydrodewaxing of heavy waxy lube base oil.The hydroisomerization performance of n-dodecane indicated that the Pt/ZSM-23 catalyst preferred to crack the C-C bond near the middle of n-dodecane chain,while the Pt/ZSM-22 catalyst was favorable for breaking the carbon chain near the end of n-dodecane.As a result,more than 2%of light products(gas plus naphtha)and3%more of heavy lube base oil with low-pour point and high viscosity index were produced on Pt/ZSM-22 than those on Pt/ZSM-23 while using the heavy waxy vacuum distillate oil as feedstock.展开更多
Phase behavior of normal decane-dodecane （n-CloH2/-CI2H26, Clo-C12） system confined in SBA-15 （Santa Barbara Amorphous, pore diameters 3.8, 7.8, and 17.2 nm） has been studied by using differential scanning calorim...Phase behavior of normal decane-dodecane （n-CloH2/-CI2H26, Clo-C12） system confined in SBA-15 （Santa Barbara Amorphous, pore diameters 3.8, 7.8, and 17.2 nm） has been studied by using differential scanning calorimetry. It has been found solid-liquid phase diagram of the C10-C12/SBA-15 system is composed of a straight line （3.8 nm）, a curve （7.8 nm） and a loop line （17.2 nm）. The growth of the phase diagram clearly shows the size effect on phase behavior of binary alkanes. Phase behavior has been compared among the systems C10H22-CI2H26]SBA-15, C12H26-C14H3o/SBA-15 and C14H30-C16H34/SBA-15.展开更多
The title compound, 2,6,8,12-tetraacetyl-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.05,9.03,11] dodecane (TAIW, C14H20N6O4, Mr = 336.36), has been synthesized by hydrogenolysis debenzylation of tetraacetyldibenzylhexaaza...The title compound, 2,6,8,12-tetraacetyl-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.05,9.03,11] dodecane (TAIW, C14H20N6O4, Mr = 336.36), has been synthesized by hydrogenolysis debenzylation of tetraacetyldibenzylhexaazaisowurtzitane (TADB) and its crystal structure was determined to be monoclinic, space group C2/c with a = 28.193(6), b = 12.139(2), c = 17.678(4) ?, β = 97.44(3)o, V = 5999(2) ?3, Z = 16, Dc = 1.490 g/cm3, F(000) = 2848, μ(MoKα) = 0.112 mm-1, R = 0.0631 and wR = 0.1586. X-ray investigations indicate that the molecule has different isomers and there exist intermolecular C–H…O hydrogen bonds in the crystal structure. The results of elemental analysis, IR and NMR spectroscopy are included.展开更多
Novel cyclic esters (1R, 2R, 3R, 5S, 7S, 9R, 12R)-3-(t-butyldimethylsilyl)oxy-7- methoxymethyloxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.05,12] dodecane were prepared when their precursor 1 was treated with SOCl2/pyri...Novel cyclic esters (1R, 2R, 3R, 5S, 7S, 9R, 12R)-3-(t-butyldimethylsilyl)oxy-7- methoxymethyloxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.05,12] dodecane were prepared when their precursor 1 was treated with SOCl2/pyridine. A plausible mechanism was hypothesized.展开更多
The unusual tricyclo[6.4.0.0^4,9]dodecane framework was constructed in eight linear steps in 13%overall yield.An innovative strategy accessing the framework from bicyclo[3.3.1]nonanes was employed.The key steps involv...The unusual tricyclo[6.4.0.0^4,9]dodecane framework was constructed in eight linear steps in 13%overall yield.An innovative strategy accessing the framework from bicyclo[3.3.1]nonanes was employed.The key steps involve a Robinson annulation,a base induced decarboxylation and epimerization in a single step,and an intramolecular alkylation.展开更多
Two novel constituents were isolated from the roots of Chinese medicinal herbs, Salvia miltiorrhiza. Their structures were determined by spectroscopic technique. The compounds were named 13,14-dihydroxy-15-methyl-benz...Two novel constituents were isolated from the roots of Chinese medicinal herbs, Salvia miltiorrhiza. Their structures were determined by spectroscopic technique. The compounds were named 13,14-dihydroxy-15-methyl-benzo[2,3-a]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(1) and 16-methyl-tropono[2,3-c]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(2).展开更多
A series of the Pt-Sn/SBA-15 catalysts were prepared and their properties characterized by using X-ray powder diffraction （XRD）, N2 adsorption-desorption, high resolution transmission electron microscope, X-ray phot...A series of the Pt-Sn/SBA-15 catalysts were prepared and their properties characterized by using X-ray powder diffraction （XRD）, N2 adsorption-desorption, high resolution transmission electron microscope, X-ray photoelectron spectroscopy （XPS） and H2-temperature programmed reduction. Their performances in long chain alkane dehydrogenation were evaluated in a fixed-bed microreactor with dodecane as a model alkane. The results indicated that SBA-15 maintained the well-order mesoporous structure during the reaction. The performance of the catalyst was found not dominated by its textural properties, but by the molar ratio of Sn to Pt which governed the degree of Sn reduction. Owing to the highest degree of Sn reduction, 1% （by mass） Pt-1.8% （by mass） Sn/SBA-15 showed the best catalytic activity. At 0.1 MPa and 470℃, the molar ratio of hydrogen to alkane at 4, and liquid hourly space velocity （LHSV） 20 h^-1, the dodecane conversion is 10%, and the dodecene selectivity is about 70%.展开更多
In this study, the azo red dyes derived from p-n-alkyl aniline by the introduction of different alkyl groups having high solubility in dodecane were synthesized. Results indicated that the elementary properties of red...In this study, the azo red dyes derived from p-n-alkyl aniline by the introduction of different alkyl groups having high solubility in dodecane were synthesized. Results indicated that the elementary properties of red oil inks were 1) non-polarity;2) low viscosity (<3.0 cps);3) specified surface tension (<30 mN/m);4) intensity of visible absorption covering 480 - 540 nm;5) hue close to standard red (CIE(x, y) = 0.67, 0.33). We can conclude that these azo red dyes are applicable for electrowetting displays.展开更多
Accurate simulation of combus-tion reactions is crucial for un-derstanding combustion mecha-nisms.Reactive force fields(ReaxFF)offer a computation-ally efficient approach to simu-lating complex combustion pro-cesses,b...Accurate simulation of combus-tion reactions is crucial for un-derstanding combustion mecha-nisms.Reactive force fields(ReaxFF)offer a computation-ally efficient approach to simu-lating complex combustion pro-cesses,but their accuracy de-pends critically on parameteri-zation.This work presents a comprehensive optimization of ReaxFF parameters for gas-phase combustion reactions using a machine learning driven ap-proach.We constructed a dataset of 33 reactions,encompassing key reaction types in combus-tion.High-level double hybrid DFT calculations served as a benchmark to evaluate the per-formance of various density functionals,the semi-empirical PM7 method,and existing ReaxFF parameter sets.We then employed the JAX-ReaxFF framework to optimize the CHO2008 parameters,leveraging its efficient local gradient-based optimization algorithms.The optimized ReaxFF significantly improved the accuracy of potential energy and atomic force predictions,with the mean absolute error(MAE)for energy approaching that of PM7.Analysis of reaction pathways and potential energy surfaces further demonstrated the en-hanced performance of the optimized force field,particularly near transition states.This opti-mized ReaxFF provides a good tool for simulating a wide range of combustion systems,and the presented methodology offers a general strategy for developing system-specific ReaxFF parameters.展开更多
基金financial supports by National Key R&D Program of China(Grant No.2017YFB0306702)are gratefully acknowledged。
文摘Nobel metallic Pt/ZSM-22 and Pt/ZSM-23 catalysts were prepared for hydroisomerization of normal dodecane and hydrodewaxing of heavy waxy lube base oil.The hydroisomerization performance of n-dodecane indicated that the Pt/ZSM-23 catalyst preferred to crack the C-C bond near the middle of n-dodecane chain,while the Pt/ZSM-22 catalyst was favorable for breaking the carbon chain near the end of n-dodecane.As a result,more than 2%of light products(gas plus naphtha)and3%more of heavy lube base oil with low-pour point and high viscosity index were produced on Pt/ZSM-22 than those on Pt/ZSM-23 while using the heavy waxy vacuum distillate oil as feedstock.
基金support from The Natural Science Foundation of Shandong Province,China(No ZR2010BM035)National Natural Science Foundation of China(No21273138)
文摘Phase behavior of normal decane-dodecane （n-CloH2/-CI2H26, Clo-C12） system confined in SBA-15 （Santa Barbara Amorphous, pore diameters 3.8, 7.8, and 17.2 nm） has been studied by using differential scanning calorimetry. It has been found solid-liquid phase diagram of the C10-C12/SBA-15 system is composed of a straight line （3.8 nm）, a curve （7.8 nm） and a loop line （17.2 nm）. The growth of the phase diagram clearly shows the size effect on phase behavior of binary alkanes. Phase behavior has been compared among the systems C10H22-CI2H26]SBA-15, C12H26-C14H3o/SBA-15 and C14H30-C16H34/SBA-15.
基金The project was supported by the National DefenceAdvanced Research Foundation of COSTIND (1206045186)
文摘The title compound, 2,6,8,12-tetraacetyl-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.05,9.03,11] dodecane (TAIW, C14H20N6O4, Mr = 336.36), has been synthesized by hydrogenolysis debenzylation of tetraacetyldibenzylhexaazaisowurtzitane (TADB) and its crystal structure was determined to be monoclinic, space group C2/c with a = 28.193(6), b = 12.139(2), c = 17.678(4) ?, β = 97.44(3)o, V = 5999(2) ?3, Z = 16, Dc = 1.490 g/cm3, F(000) = 2848, μ(MoKα) = 0.112 mm-1, R = 0.0631 and wR = 0.1586. X-ray investigations indicate that the molecule has different isomers and there exist intermolecular C–H…O hydrogen bonds in the crystal structure. The results of elemental analysis, IR and NMR spectroscopy are included.
文摘Novel cyclic esters (1R, 2R, 3R, 5S, 7S, 9R, 12R)-3-(t-butyldimethylsilyl)oxy-7- methoxymethyloxy-2, 10-dimethyl-12-oxatricyclo [7.2.1.05,12] dodecane were prepared when their precursor 1 was treated with SOCl2/pyridine. A plausible mechanism was hypothesized.
基金Financial support from TianJin Municipal Science and Technology Commission(No.11ZCKFSY06200) is greatly acknowledged
文摘The unusual tricyclo[6.4.0.0^4,9]dodecane framework was constructed in eight linear steps in 13%overall yield.An innovative strategy accessing the framework from bicyclo[3.3.1]nonanes was employed.The key steps involve a Robinson annulation,a base induced decarboxylation and epimerization in a single step,and an intramolecular alkylation.
文摘Two novel constituents were isolated from the roots of Chinese medicinal herbs, Salvia miltiorrhiza. Their structures were determined by spectroscopic technique. The compounds were named 13,14-dihydroxy-15-methyl-benzo[2,3-a]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(1) and 16-methyl-tropono[2,3-c]-7,7-dimethyl-12-oxa-tricyclo[4,4,21.4,0]dodecane(2).
基金Supported by the National Natural Science Foundation of China （20376005）.
文摘A series of the Pt-Sn/SBA-15 catalysts were prepared and their properties characterized by using X-ray powder diffraction （XRD）, N2 adsorption-desorption, high resolution transmission electron microscope, X-ray photoelectron spectroscopy （XPS） and H2-temperature programmed reduction. Their performances in long chain alkane dehydrogenation were evaluated in a fixed-bed microreactor with dodecane as a model alkane. The results indicated that SBA-15 maintained the well-order mesoporous structure during the reaction. The performance of the catalyst was found not dominated by its textural properties, but by the molar ratio of Sn to Pt which governed the degree of Sn reduction. Owing to the highest degree of Sn reduction, 1% （by mass） Pt-1.8% （by mass） Sn/SBA-15 showed the best catalytic activity. At 0.1 MPa and 470℃, the molar ratio of hydrogen to alkane at 4, and liquid hourly space velocity （LHSV） 20 h^-1, the dodecane conversion is 10%, and the dodecene selectivity is about 70%.
文摘In this study, the azo red dyes derived from p-n-alkyl aniline by the introduction of different alkyl groups having high solubility in dodecane were synthesized. Results indicated that the elementary properties of red oil inks were 1) non-polarity;2) low viscosity (<3.0 cps);3) specified surface tension (<30 mN/m);4) intensity of visible absorption covering 480 - 540 nm;5) hue close to standard red (CIE(x, y) = 0.67, 0.33). We can conclude that these azo red dyes are applicable for electrowetting displays.
基金supported by the National Key R&D Program of China (No.2023YFF1204903)the National Natural Science Foundation of China (Nos. 22222303,22173032, 22361132538, 92461313)the Artificial Intelligence-Driven Reform of Scientific Research Paradigms:Empowerment Program for Discipline Advancement (No.2024AI01009)。
文摘Accurate simulation of combus-tion reactions is crucial for un-derstanding combustion mecha-nisms.Reactive force fields(ReaxFF)offer a computation-ally efficient approach to simu-lating complex combustion pro-cesses,but their accuracy de-pends critically on parameteri-zation.This work presents a comprehensive optimization of ReaxFF parameters for gas-phase combustion reactions using a machine learning driven ap-proach.We constructed a dataset of 33 reactions,encompassing key reaction types in combus-tion.High-level double hybrid DFT calculations served as a benchmark to evaluate the per-formance of various density functionals,the semi-empirical PM7 method,and existing ReaxFF parameter sets.We then employed the JAX-ReaxFF framework to optimize the CHO2008 parameters,leveraging its efficient local gradient-based optimization algorithms.The optimized ReaxFF significantly improved the accuracy of potential energy and atomic force predictions,with the mean absolute error(MAE)for energy approaching that of PM7.Analysis of reaction pathways and potential energy surfaces further demonstrated the en-hanced performance of the optimized force field,particularly near transition states.This opti-mized ReaxFF provides a good tool for simulating a wide range of combustion systems,and the presented methodology offers a general strategy for developing system-specific ReaxFF parameters.
