A hetero-crystalline seeding method to prepare a unique MFI type zeolite with mesopores of ca. 4 nm diameter designated as the ZRP zeolite, which possesses high stability and selectivity and is used as component of FC...A hetero-crystalline seeding method to prepare a unique MFI type zeolite with mesopores of ca. 4 nm diameter designated as the ZRP zeolite, which possesses high stability and selectivity and is used as component of FCC catalysts to produce high-octane gasoline and light olefins, was developed. With the DOCR and DOCP catalysts containing the ZRP zeolite modified by phosphorus-incorporation as the octaneenhancing catalysts, the commercial trial was carried out in a 0.8Mt/a RFCC unit with a feedstock composed of Daqing atmospheric residue. As compared to the base catalyst, the LPG+gasoline+LCO product yield obtained from this catalyst was increased by 0.53m%. Meanwhile, the RON and MON of gasoline was increased by 1.4 and 2.4 units, respectively. The higher increment of MON is attributable to the higher isoparaffines content in gasoline. This result indicates that the ZRP zeolite possesses higher isomerization selectivity.展开更多
The isobaric vapor-liquid equilibrium data of systems of ethyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> andisopropyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub...The isobaric vapor-liquid equilibrium data of systems of ethyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> andisopropyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> were determined at 0.0709 MPa and 0.1013 MPa by using a modifiedRose-Williams still.The experimental data were tested for thermodynamical consistency and correlatedsatisfactorily with p-T equation of state and Wilson equation.展开更多
In this study,the spray auto-ignition properties of binary primary reference fuels(PRFs)of 2,2,4-trimethylpentane and n-heptane with different research octane numbers(RONs)were measured according to the industry stand...In this study,the spray auto-ignition properties of binary primary reference fuels(PRFs)of 2,2,4-trimethylpentane and n-heptane with different research octane numbers(RONs)were measured according to the industry standard NB/SH/T 6035 to determine their ignition delay times at various initial temperatures.Furthermore,the auto-ignition properties were investigated after blending the PRFs with various amounts of ethanol.The results revealed a very good correlation between the derived cetane number and the RON for the PRFs in both the presence and absence of ethanol.In addition,a concept of ignition delay sensitivity was developed for ethanol-containing fuels that exhibited a close relationship with the octane sensitivity,which is defined as the RON minus the motor octane number(MON).Finally,the developed method was applied to conveniently estimate the RON and MON values of several ethanol-containing fuels by simply measuring their auto-ignition properties.展开更多
The title compound (C31H29NO, Mr = 431.6) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallized in orthorhombic space group Pcab, with cell parameters: a = 10.579 (3), b...The title compound (C31H29NO, Mr = 431.6) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallized in orthorhombic space group Pcab, with cell parameters: a = 10.579 (3), b = 18.514(7) , c = 23.93(1) ?, V = 4686.22(3) ?3, Z = 8, Dc = 1.223g/cm3, F(000) = 1840, μ = 0.68mm-1. The structure was solved by direct methods and refined by full-matrix least-squares method, and final R = 0.057, Rw = 0.060 for 2282 observed reflections with I ≥3.00σ(I). The molecular backbone is aza-bicycle [3,2,1]octane containing a chair-like six-membered aza-cycle conformation.展开更多
The title compound (C23H22N2O) 3 has been synthesized by the reaction of (S)- (-)-1,1-diphenyl-2-pyrrolidinemethanol 1 with 2-pyridinecarboxaldehyde 2 in refluxing benzene catalyzed by TsOH, and its structure was dete...The title compound (C23H22N2O) 3 has been synthesized by the reaction of (S)- (-)-1,1-diphenyl-2-pyrrolidinemethanol 1 with 2-pyridinecarboxaldehyde 2 in refluxing benzene catalyzed by TsOH, and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space group P212121 with a = 8.4747(8), b = 10.8829(10), c = 19.777(2) , Mr = 342.43, V =1824.0(3) 3, Dc = 1.247 g/cm3, Z = 4, m = 0.077 mm-1 and F(000) = 728. The structure was solved by direct methods and refined by full-matrix least-squares techniques to the final R = 0.0497 and wR = 0.0927.展开更多
Parkinson's disease (PD) is a common neurodegenerative condition associated with the degeneration of dopaminergic neurons in the zona compacta of the substantia nigra. 3D QSAR study of 8-azabicyclo [3.2.1] octane ...Parkinson's disease (PD) is a common neurodegenerative condition associated with the degeneration of dopaminergic neurons in the zona compacta of the substantia nigra. 3D QSAR study of 8-azabicyclo [3.2.1] octane analogs which serves as the pathfinder for the design of novel molecule for anti Parkinsonism. Five compounds of 8-azabicyclo [3.2.1] octane analogs are synthesized and the anti Parkinsonism activity and brain dopamine level were studied on albino mice. The anti Parkinsonian activity was determined by the effect of test compound A-F on drug induced catatonia using the method of Morpurgo. Atropine as well as compounds B and E significantly reduced the catatonic responses and tremors induced by chlorpromazine. The level of dopamine was measured after the administration of atropine and the test compounds in brain of mice. The study reveals that the compounds B and E have exhibited significant activity over atropine.展开更多
Least square support vector machine (LSSVM) combined with successive projection algorithm (SPA) method was applied for?near-infrared (NIR)?quantitative determination of the octane number in fuel petrol. The NIR spectr...Least square support vector machine (LSSVM) combined with successive projection algorithm (SPA) method was applied for?near-infrared (NIR)?quantitative determination of the octane number in fuel petrol. The NIR spectra of 87 fuel petrol samples were?scanned?for model establishment and optimization. First order derivative Savitzky-Golay smoother?(1st-d’SG) was?utilized to improve the?NIR predictive ability. Its pretreatment effect was compared with the raw data.?SPA was?applied for the extraction of informative wavelengths. Considering the linear and non-linear?training mechanism,?LSSVM?regression was employed to establish calibration models.?The correlation coefficient (R) and root mean square error (RMSE) were used as the model evaluation indices;accordingly the octane number in fuel petrol?was quantitatively determined with the prospective predictive indices. Results showed that?after pretreated by 1st-d’SG, 8 SPA-selected wavelengths?was generated as the inputs of LSSVM, so that the calibration models were optimized in the way of combining the SPA-LSSVM regression with the SG smoother.?The prediction results were quite satisfactory, with the calibrating correlation coefficient of?0.951 and the RMSE?of 3.282. An independent?testing?sample set was used to evaluate the optimal model, the testing?correlation coefficient?was 0.903 and the RMSE was 4.128. We conclude that?NIR spectrometry is feasible to determine the octane in fuel petrol?by establishing SPA-LSSVM?models. The 1st-d’SG pretreatment has?the?advantage of selecting wavelengths containing the implicit information. The combination of 1st-d’SG pretreatment and SPA-LSSVM show its applicable potential to predict the?octane number?in?fuel petrol.展开更多
Halide perovskite (CsPbX3, X = C1, Br, or I) quantum dots have received increasing attention as novel colloidal nanocrystals (NCs). Accurate control of emission bands and NC morphologies are vital prerequisites fo...Halide perovskite (CsPbX3, X = C1, Br, or I) quantum dots have received increasing attention as novel colloidal nanocrystals (NCs). Accurate control of emission bands and NC morphologies are vital prerequisites for most CsPbX3 NC practical applications. Therefore, a facile method of synthesizing CsPbX3 (X = C1, Br, or I) NCs in the nonpolar solvent octane was developed. The process was conducted in air at - 90℃ to synthesize high-quality CsPbX3 NCs showing 12-44 nm wide emission and high photoluminescence quantum yield, exceeding 90%. An in situ anion-exchange method was developed to tune CsPbX3 NC photoluminescence emission, using PbX2 dissolved in octane as the halide source. NC morphology was controlled by dissolving specific metal-organic salts in the precursor solution prior to nucleation, and nanocubes, nanodots, nanosheets, nanoplatelets, nanorods, and nanowires were obtained following the same general method providing a facile, versatile route to controlling CsPbX3 NC emission bands and morphologies, which will broaden the range of CsPbX3 NC practical applications.展开更多
An improved and scalable process for substituted 3,8-diazabicyclo[3.2.1]octane was developed.N-Benzyl-2,5-dicarbethoxy-pyrrolidine 2 was reduced to N-benzyl-2.5-dihydroxymethylpyrrolidine 9 and subsequently debenzylat...An improved and scalable process for substituted 3,8-diazabicyclo[3.2.1]octane was developed.N-Benzyl-2,5-dicarbethoxy-pyrrolidine 2 was reduced to N-benzyl-2.5-dihydroxymethylpyrrolidine 9 and subsequently debenzylated to afford N-Boc-2,5- dihydroxymethylpyrrolidine 10.After mesylation of the diol 10 and cyclization with benzylamine,a diversity of scaffold,3,8- diazabicyclo[3.2.1]octane analogue 12 was obtained in a total yield of 42%in five steps.展开更多
A photocatalytic tandem cyclization of o-alkenylbenzaldehydes using pyridinium salts as the amination reagent is described.A variety of valuable seven-membered nitrogenous heterocyclic skeletons are prepared in modest...A photocatalytic tandem cyclization of o-alkenylbenzaldehydes using pyridinium salts as the amination reagent is described.A variety of valuable seven-membered nitrogenous heterocyclic skeletons are prepared in modest to excellent yields in concise one-step.This transformation features mild reaction conditions and exceptional functional group tolerance.In addition,combining control experiments and density functional theory(DFT)calculations on the mechanism can explain the reaction selectivity.展开更多
<正> A new series of dextrorotatory derivatives of 1R,3RS,5S-1,8,8-trimethyl-2,4,3-diazaphosphabicyclo [3.2.1] octane with a newly formed chiral phosphorus atom has been prepared by an asymmetric reaction of (+)...<正> A new series of dextrorotatory derivatives of 1R,3RS,5S-1,8,8-trimethyl-2,4,3-diazaphosphabicyclo [3.2.1] octane with a newly formed chiral phosphorus atom has been prepared by an asymmetric reaction of (+)-cis-1R,3S-1,2,2-trimethyl-1,3-cyclopentadiamine with some thiophosphoryl dichlorides. The optically active products consisted of two unequal amounts of diastereomers,(1R, 3R, 5S) isomers and(1R, 3S, 5S) isomers. Two regioselective reactions took place when phenoxy thiophosphoryl dichloride and N,N-dialkylamino thiophosphoryl dichlorides were chosen as the reagents for the reaction. The content of (1R, 3R, 5S) isomers in the product was over 90% for the former and there were only (1R, 3S, 5S) isomers obtained for the latter.展开更多
Octanes in alkylation products obtained from industrial alkylation were studied by batch experiments.More than eight octane isomers were identified and quantified by gas chromatography-mass spectrometry.Based on a cla...Octanes in alkylation products obtained from industrial alkylation were studied by batch experiments.More than eight octane isomers were identified and quantified by gas chromatography-mass spectrometry.Based on a classic carbenium ion mechanism,the carbocation transition states in concentrated sulfuric acid catalyzed alkylation were investigated using quantum-chemical simulations and predicted the concentration and octane isomerization products including trimethylpentane and dimethylhexane as well as the formation of heavier compounds that resulted from the oligomerization of octane and butene.The agreement between model calculations and experimental data was quite satisfactory.Calculation results indicated that composition and content of trimethylpentanes in the alkylation products were 2,2,4-trimethylpentane>2,3,3-trimethylpentane>2,3,4-trimethylpentane>2,2,3-trimethylpentane whether the 2-butene or i-butene acts as olefin.Heavier compounds in the alkylate were primarily formed by the oligomerization of dimethylhexane with 1-butene.Hopefully,the carbocation transition state models developed in this work will be useful for understanding the product distributions of octane in alkylation products.展开更多
Summary of main observation and conclusion A Cu(I)-catalyzed three-component reaction of terminal enynals/enynones,diazo compounds,and al kenes has been developed.With this method,a series of oxabicyclo[2.2.2]octanes ...Summary of main observation and conclusion A Cu(I)-catalyzed three-component reaction of terminal enynals/enynones,diazo compounds,and al kenes has been developed.With this method,a series of oxabicyclo[2.2.2]octanes were effectively synthesized in high yields under mild reaction condi-tions.This transformation is proposed to proceed through trapping of the cyclic vinyl-o-quinodimethanes(vinyI-o-QDMs)species,which were generated from terminal enynals/enynones and diazo compounds by alkenes.The obvious advantages of wide substrate scopes,mild reaction conditions,and high seteroselectivity and atom eficiency make this reaction highly appealing for construction of highly rigid[2.2.2]octane skeleton.展开更多
We report the divergent synthesis of benzannulated 2,8-dioxabicyclo[3.2.1]octanes and 2,3-dihydrobenzofurans using the concept of extended Corey-Chaykovsky reactions.With this concept,2-hydroxychalcones were treated w...We report the divergent synthesis of benzannulated 2,8-dioxabicyclo[3.2.1]octanes and 2,3-dihydrobenzofurans using the concept of extended Corey-Chaykovsky reactions.With this concept,2-hydroxychalcones were treated with the Corey ylide providing highly reactive donor-acceptor cyclopropanes that were introduced in a one pot manner for further transformations.展开更多
In this paper,a novel copper-based catalyst for FCC gasoline improving the ability of removal the sulfur and avoiding the loss of the octane number from olefin saturation by reactive adsorption desulfurization(RADS) w...In this paper,a novel copper-based catalyst for FCC gasoline improving the ability of removal the sulfur and avoiding the loss of the octane number from olefin saturation by reactive adsorption desulfurization(RADS) was investigated.The series of Cu/Zn O-Al_2 O_3 catalysts were characterized by X-ray powder diffraction(XRD),N_2 adsorption analysis and temperature-programmed reduction(TPR) studies,X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM) and transmission electron microscopy(TEM).The experiment results showed that the catalysts had an optimum desulfurization ability with copper loading 6 wt%,which the sulfur contents of product decreased less than 10 μg/g and olefin contents decreased from 16.19% to 14.14% for the long period operation.The appropriate Cu loading content could lead to the high active and low apparent activation energy(E_a).Therefore,the Cu-based catalyst may become a novel catalyst for second-generation for reactive adsorption desulfurization,which achieves the high desulfurization active and low olefins saturation to satisfy the upgrading the product.展开更多
The reaction activity of S Zorb sorbents with different sulfur contents was investigated, and the structure and composition of carbon-containing sorbents were characterized by XRD, FT-IR and TG-MS in order to delve in...The reaction activity of S Zorb sorbents with different sulfur contents was investigated, and the structure and composition of carbon-containing sorbents were characterized by XRD, FT-IR and TG-MS in order to delve into the kind and morphology of carbon on the sorbent. Test results have revealed that coke could be deposited on the S Zorb sorbent during the operating process, and the coke content was an important factor influencing the reaction performance of the S Zorb sorbent. Retention of a definite amount of coke on the sorbent while securing the desulfurization activity of the S Zorb sorbent would be conducive to the reduction of octane loss of reaction product.展开更多
A new type of zeolite La-USL (ultra stable zeolite L (zeolite USL) modified by La), which has superior activity, stability and selectivity in catalytic cracking of hydrocarbons and thus can be used as an active ca...A new type of zeolite La-USL (ultra stable zeolite L (zeolite USL) modified by La), which has superior activity, stability and selectivity in catalytic cracking of hydrocarbons and thus can be used as an active catalyst component, is reported in this paper. The zeolite L with relative crystallinity of above 90% was synthesized by the hydrothermal crystallization method under optimum conditions and characterized by means of XRD, NH3-TPD and isotherm adsorption techniques. The in-situ synthesized zeolite L with a SiO2/Al2O3 mole ratio of 5-6 was modified by cation ion exchange, hydrothermal dealumination and chemical modifications with La in order to prepare La-containing USL with a higher framework SiO2/Al2O3 mole ratio of 15-30. The modified zeolite La-USL was used as an active additive component of fluid catalytic cracking (FCC) catalyst and the resulting catalysts were evaluated by microactivity test (MAT) and fixed-fluidized bed (FFB) experiments using heavy oil as feedstock. The influence of La content in La- USL on cracking product distribution, gasoline group composition and research octane number (RON) was investigated. The results showed that when La content in La-USL was 0.8 wt%, the addition of the corresponding La-USL could result in a FCC catalyst that produced significant improvement in product distribution and gasoline quality.展开更多
This article refers to major measures for reducing olefin content of automotive gasoline and the effect after adoption of these measures. The key for reducing olefin content in China's automotive gasoline pool is ...This article refers to major measures for reducing olefin content of automotive gasoline and the effect after adoption of these measures. The key for reducing olefin content in China's automotive gasoline pool is to reduce the olefin content of FCC naphtha. The domestic refiners apply the olefinreducing catalyst to decrease the olefin content of FCC gasoline as a convenient and cheap means to meet the national standard for automotive gasoline at the present phase. Furthermore, the novel domestic FCC reaction processes, such as the MIP, MGD, FDFCC and other processes can also apparently reduce olefin content in FCC gasoline. In order to further reduce the olefin content in gasoline to meet more stringent standard for automotive gasoline, Chinese refiners should optimize the processing scheme while aggressively disseminating hydrogenation process along with development of catalytic reforming,alkylation, etherification and other processes to completely change the simplistic composition of domestic gasoline pool.展开更多
Because of its high density and low cetane number, the light cycle oil(LCO) containing heavy aromatics(60%—80%) can hardly be transformed through the conventional hydro-upgrading technology. In this report, a novel L...Because of its high density and low cetane number, the light cycle oil(LCO) containing heavy aromatics(60%—80%) can hardly be transformed through the conventional hydro-upgrading technology. In this report, a novel LCO hydrocracking technology(FD2G) was proposed for the utilization of LCO to manufacture high value-added products. Through the ingenious combination of hydroprocessing catalyst and the hydrocracking process, the high octane gasoline and the ultra-low sulfur diesel(ULSD) blendstocks were produced simultaneously. The influence of catalyst type, reaction temperature, pressure, respectively, on the research octane number(RON) of produced gasoline was studied in a fixed bed hydrogenation reactor. It indicated that high reaction temperature and medium pressure would favor the production of highoctane gasoline through the conversion of bi-aromatic and tri-aromatic hydrocarbons. The typical results of FD2 G technology on commercial units showed that it could produce clean diesel with a sulfur content of less than 10 μg/g and clean gasoline with a research octane number(RON) of up to 92. It would be contributed to the achievement of the maximum profit of a refinery, the FD2 G technology could provide a higher economic efficiency than the other diesel quality upgrading technology under the current gasoline and diesel price system.展开更多
文摘A hetero-crystalline seeding method to prepare a unique MFI type zeolite with mesopores of ca. 4 nm diameter designated as the ZRP zeolite, which possesses high stability and selectivity and is used as component of FCC catalysts to produce high-octane gasoline and light olefins, was developed. With the DOCR and DOCP catalysts containing the ZRP zeolite modified by phosphorus-incorporation as the octaneenhancing catalysts, the commercial trial was carried out in a 0.8Mt/a RFCC unit with a feedstock composed of Daqing atmospheric residue. As compared to the base catalyst, the LPG+gasoline+LCO product yield obtained from this catalyst was increased by 0.53m%. Meanwhile, the RON and MON of gasoline was increased by 1.4 and 2.4 units, respectively. The higher increment of MON is attributable to the higher isoparaffines content in gasoline. This result indicates that the ZRP zeolite possesses higher isomerization selectivity.
文摘The isobaric vapor-liquid equilibrium data of systems of ethyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> andisopropyl acetate<sub>(1)</sub>-n-octane<sub>(2)</sub> were determined at 0.0709 MPa and 0.1013 MPa by using a modifiedRose-Williams still.The experimental data were tested for thermodynamical consistency and correlatedsatisfactorily with p-T equation of state and Wilson equation.
基金This work was funded by the National Key Research and Development Program(2017YFB0306505).
文摘In this study,the spray auto-ignition properties of binary primary reference fuels(PRFs)of 2,2,4-trimethylpentane and n-heptane with different research octane numbers(RONs)were measured according to the industry standard NB/SH/T 6035 to determine their ignition delay times at various initial temperatures.Furthermore,the auto-ignition properties were investigated after blending the PRFs with various amounts of ethanol.The results revealed a very good correlation between the derived cetane number and the RON for the PRFs in both the presence and absence of ethanol.In addition,a concept of ignition delay sensitivity was developed for ethanol-containing fuels that exhibited a close relationship with the octane sensitivity,which is defined as the RON minus the motor octane number(MON).Finally,the developed method was applied to conveniently estimate the RON and MON values of several ethanol-containing fuels by simply measuring their auto-ignition properties.
文摘The title compound (C31H29NO, Mr = 431.6) was synthesized and its crystal structure was determined by X-ray diffraction method. It crystallized in orthorhombic space group Pcab, with cell parameters: a = 10.579 (3), b = 18.514(7) , c = 23.93(1) ?, V = 4686.22(3) ?3, Z = 8, Dc = 1.223g/cm3, F(000) = 1840, μ = 0.68mm-1. The structure was solved by direct methods and refined by full-matrix least-squares method, and final R = 0.057, Rw = 0.060 for 2282 observed reflections with I ≥3.00σ(I). The molecular backbone is aza-bicycle [3,2,1]octane containing a chair-like six-membered aza-cycle conformation.
基金the National Natural Science Foundation of China (No. 20172039)
文摘The title compound (C23H22N2O) 3 has been synthesized by the reaction of (S)- (-)-1,1-diphenyl-2-pyrrolidinemethanol 1 with 2-pyridinecarboxaldehyde 2 in refluxing benzene catalyzed by TsOH, and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space group P212121 with a = 8.4747(8), b = 10.8829(10), c = 19.777(2) , Mr = 342.43, V =1824.0(3) 3, Dc = 1.247 g/cm3, Z = 4, m = 0.077 mm-1 and F(000) = 728. The structure was solved by direct methods and refined by full-matrix least-squares techniques to the final R = 0.0497 and wR = 0.0927.
文摘Parkinson's disease (PD) is a common neurodegenerative condition associated with the degeneration of dopaminergic neurons in the zona compacta of the substantia nigra. 3D QSAR study of 8-azabicyclo [3.2.1] octane analogs which serves as the pathfinder for the design of novel molecule for anti Parkinsonism. Five compounds of 8-azabicyclo [3.2.1] octane analogs are synthesized and the anti Parkinsonism activity and brain dopamine level were studied on albino mice. The anti Parkinsonian activity was determined by the effect of test compound A-F on drug induced catatonia using the method of Morpurgo. Atropine as well as compounds B and E significantly reduced the catatonic responses and tremors induced by chlorpromazine. The level of dopamine was measured after the administration of atropine and the test compounds in brain of mice. The study reveals that the compounds B and E have exhibited significant activity over atropine.
文摘Least square support vector machine (LSSVM) combined with successive projection algorithm (SPA) method was applied for?near-infrared (NIR)?quantitative determination of the octane number in fuel petrol. The NIR spectra of 87 fuel petrol samples were?scanned?for model establishment and optimization. First order derivative Savitzky-Golay smoother?(1st-d’SG) was?utilized to improve the?NIR predictive ability. Its pretreatment effect was compared with the raw data.?SPA was?applied for the extraction of informative wavelengths. Considering the linear and non-linear?training mechanism,?LSSVM?regression was employed to establish calibration models.?The correlation coefficient (R) and root mean square error (RMSE) were used as the model evaluation indices;accordingly the octane number in fuel petrol?was quantitatively determined with the prospective predictive indices. Results showed that?after pretreated by 1st-d’SG, 8 SPA-selected wavelengths?was generated as the inputs of LSSVM, so that the calibration models were optimized in the way of combining the SPA-LSSVM regression with the SG smoother.?The prediction results were quite satisfactory, with the calibrating correlation coefficient of?0.951 and the RMSE?of 3.282. An independent?testing?sample set was used to evaluate the optimal model, the testing?correlation coefficient?was 0.903 and the RMSE was 4.128. We conclude that?NIR spectrometry is feasible to determine the octane in fuel petrol?by establishing SPA-LSSVM?models. The 1st-d’SG pretreatment has?the?advantage of selecting wavelengths containing the implicit information. The combination of 1st-d’SG pretreatment and SPA-LSSVM show its applicable potential to predict the?octane number?in?fuel petrol.
文摘Halide perovskite (CsPbX3, X = C1, Br, or I) quantum dots have received increasing attention as novel colloidal nanocrystals (NCs). Accurate control of emission bands and NC morphologies are vital prerequisites for most CsPbX3 NC practical applications. Therefore, a facile method of synthesizing CsPbX3 (X = C1, Br, or I) NCs in the nonpolar solvent octane was developed. The process was conducted in air at - 90℃ to synthesize high-quality CsPbX3 NCs showing 12-44 nm wide emission and high photoluminescence quantum yield, exceeding 90%. An in situ anion-exchange method was developed to tune CsPbX3 NC photoluminescence emission, using PbX2 dissolved in octane as the halide source. NC morphology was controlled by dissolving specific metal-organic salts in the precursor solution prior to nucleation, and nanocubes, nanodots, nanosheets, nanoplatelets, nanorods, and nanowires were obtained following the same general method providing a facile, versatile route to controlling CsPbX3 NC emission bands and morphologies, which will broaden the range of CsPbX3 NC practical applications.
基金supported by the program of research fund for returning scholars of Ministry of Education of China(No.200812053)
文摘An improved and scalable process for substituted 3,8-diazabicyclo[3.2.1]octane was developed.N-Benzyl-2,5-dicarbethoxy-pyrrolidine 2 was reduced to N-benzyl-2.5-dihydroxymethylpyrrolidine 9 and subsequently debenzylated to afford N-Boc-2,5- dihydroxymethylpyrrolidine 10.After mesylation of the diol 10 and cyclization with benzylamine,a diversity of scaffold,3,8- diazabicyclo[3.2.1]octane analogue 12 was obtained in a total yield of 42%in five steps.
基金the National Natural Science Foundation of China(21632003,21871116)the Key Program of Gansu Province(17ZD2GC011)the‘‘111’’Program from the MOE of China。
文摘A photocatalytic tandem cyclization of o-alkenylbenzaldehydes using pyridinium salts as the amination reagent is described.A variety of valuable seven-membered nitrogenous heterocyclic skeletons are prepared in modest to excellent yields in concise one-step.This transformation features mild reaction conditions and exceptional functional group tolerance.In addition,combining control experiments and density functional theory(DFT)calculations on the mechanism can explain the reaction selectivity.
文摘<正> A new series of dextrorotatory derivatives of 1R,3RS,5S-1,8,8-trimethyl-2,4,3-diazaphosphabicyclo [3.2.1] octane with a newly formed chiral phosphorus atom has been prepared by an asymmetric reaction of (+)-cis-1R,3S-1,2,2-trimethyl-1,3-cyclopentadiamine with some thiophosphoryl dichlorides. The optically active products consisted of two unequal amounts of diastereomers,(1R, 3R, 5S) isomers and(1R, 3S, 5S) isomers. Two regioselective reactions took place when phenoxy thiophosphoryl dichloride and N,N-dialkylamino thiophosphoryl dichlorides were chosen as the reagents for the reaction. The content of (1R, 3R, 5S) isomers in the product was over 90% for the former and there were only (1R, 3S, 5S) isomers obtained for the latter.
基金International(regional)cooperation and exchange program(Grant No.21961160740)the open foundation of State Key Laboratory of Chemical Engineering(Grant No.SKL-ChE-19B02)the North University of China Graduate Science and Technology Project(Grant Nos.20191621,20191626).
文摘Octanes in alkylation products obtained from industrial alkylation were studied by batch experiments.More than eight octane isomers were identified and quantified by gas chromatography-mass spectrometry.Based on a classic carbenium ion mechanism,the carbocation transition states in concentrated sulfuric acid catalyzed alkylation were investigated using quantum-chemical simulations and predicted the concentration and octane isomerization products including trimethylpentane and dimethylhexane as well as the formation of heavier compounds that resulted from the oligomerization of octane and butene.The agreement between model calculations and experimental data was quite satisfactory.Calculation results indicated that composition and content of trimethylpentanes in the alkylation products were 2,2,4-trimethylpentane>2,3,3-trimethylpentane>2,3,4-trimethylpentane>2,2,3-trimethylpentane whether the 2-butene or i-butene acts as olefin.Heavier compounds in the alkylate were primarily formed by the oligomerization of dimethylhexane with 1-butene.Hopefully,the carbocation transition state models developed in this work will be useful for understanding the product distributions of octane in alkylation products.
基金We appreciate financial support from Ministry of Science and Technology of the People's Republic of China(2016YFA0602900)the National Natural Science Foundation of China(21871096,21672071)+1 种基金Guangdong Science and Technology Department(20188030308007,2018A030310359,2016A030310433)the Science and Technology Program of Guangzhou(201707010316,201707010168).
文摘Summary of main observation and conclusion A Cu(I)-catalyzed three-component reaction of terminal enynals/enynones,diazo compounds,and al kenes has been developed.With this method,a series of oxabicyclo[2.2.2]octanes were effectively synthesized in high yields under mild reaction condi-tions.This transformation is proposed to proceed through trapping of the cyclic vinyl-o-quinodimethanes(vinyI-o-QDMs)species,which were generated from terminal enynals/enynones and diazo compounds by alkenes.The obvious advantages of wide substrate scopes,mild reaction conditions,and high seteroselectivity and atom eficiency make this reaction highly appealing for construction of highly rigid[2.2.2]octane skeleton.
基金We thank the Russian Science Foundation(Grant 21-73-20095)for support of this work.
文摘We report the divergent synthesis of benzannulated 2,8-dioxabicyclo[3.2.1]octanes and 2,3-dihydrobenzofurans using the concept of extended Corey-Chaykovsky reactions.With this concept,2-hydroxychalcones were treated with the Corey ylide providing highly reactive donor-acceptor cyclopropanes that were introduced in a one pot manner for further transformations.
基金financially support by the National Natural Science Foundation (Grants No.2117625821676300)the Fundamental Research Funds for the Central Universities (Grants No.15CX06051A)
文摘In this paper,a novel copper-based catalyst for FCC gasoline improving the ability of removal the sulfur and avoiding the loss of the octane number from olefin saturation by reactive adsorption desulfurization(RADS) was investigated.The series of Cu/Zn O-Al_2 O_3 catalysts were characterized by X-ray powder diffraction(XRD),N_2 adsorption analysis and temperature-programmed reduction(TPR) studies,X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM) and transmission electron microscopy(TEM).The experiment results showed that the catalysts had an optimum desulfurization ability with copper loading 6 wt%,which the sulfur contents of product decreased less than 10 μg/g and olefin contents decreased from 16.19% to 14.14% for the long period operation.The appropriate Cu loading content could lead to the high active and low apparent activation energy(E_a).Therefore,the Cu-based catalyst may become a novel catalyst for second-generation for reactive adsorption desulfurization,which achieves the high desulfurization active and low olefins saturation to satisfy the upgrading the product.
文摘The reaction activity of S Zorb sorbents with different sulfur contents was investigated, and the structure and composition of carbon-containing sorbents were characterized by XRD, FT-IR and TG-MS in order to delve into the kind and morphology of carbon on the sorbent. Test results have revealed that coke could be deposited on the S Zorb sorbent during the operating process, and the coke content was an important factor influencing the reaction performance of the S Zorb sorbent. Retention of a definite amount of coke on the sorbent while securing the desulfurization activity of the S Zorb sorbent would be conducive to the reduction of octane loss of reaction product.
文摘A new type of zeolite La-USL (ultra stable zeolite L (zeolite USL) modified by La), which has superior activity, stability and selectivity in catalytic cracking of hydrocarbons and thus can be used as an active catalyst component, is reported in this paper. The zeolite L with relative crystallinity of above 90% was synthesized by the hydrothermal crystallization method under optimum conditions and characterized by means of XRD, NH3-TPD and isotherm adsorption techniques. The in-situ synthesized zeolite L with a SiO2/Al2O3 mole ratio of 5-6 was modified by cation ion exchange, hydrothermal dealumination and chemical modifications with La in order to prepare La-containing USL with a higher framework SiO2/Al2O3 mole ratio of 15-30. The modified zeolite La-USL was used as an active additive component of fluid catalytic cracking (FCC) catalyst and the resulting catalysts were evaluated by microactivity test (MAT) and fixed-fluidized bed (FFB) experiments using heavy oil as feedstock. The influence of La content in La- USL on cracking product distribution, gasoline group composition and research octane number (RON) was investigated. The results showed that when La content in La-USL was 0.8 wt%, the addition of the corresponding La-USL could result in a FCC catalyst that produced significant improvement in product distribution and gasoline quality.
文摘This article refers to major measures for reducing olefin content of automotive gasoline and the effect after adoption of these measures. The key for reducing olefin content in China's automotive gasoline pool is to reduce the olefin content of FCC naphtha. The domestic refiners apply the olefinreducing catalyst to decrease the olefin content of FCC gasoline as a convenient and cheap means to meet the national standard for automotive gasoline at the present phase. Furthermore, the novel domestic FCC reaction processes, such as the MIP, MGD, FDFCC and other processes can also apparently reduce olefin content in FCC gasoline. In order to further reduce the olefin content in gasoline to meet more stringent standard for automotive gasoline, Chinese refiners should optimize the processing scheme while aggressively disseminating hydrogenation process along with development of catalytic reforming,alkylation, etherification and other processes to completely change the simplistic composition of domestic gasoline pool.
文摘Because of its high density and low cetane number, the light cycle oil(LCO) containing heavy aromatics(60%—80%) can hardly be transformed through the conventional hydro-upgrading technology. In this report, a novel LCO hydrocracking technology(FD2G) was proposed for the utilization of LCO to manufacture high value-added products. Through the ingenious combination of hydroprocessing catalyst and the hydrocracking process, the high octane gasoline and the ultra-low sulfur diesel(ULSD) blendstocks were produced simultaneously. The influence of catalyst type, reaction temperature, pressure, respectively, on the research octane number(RON) of produced gasoline was studied in a fixed bed hydrogenation reactor. It indicated that high reaction temperature and medium pressure would favor the production of highoctane gasoline through the conversion of bi-aromatic and tri-aromatic hydrocarbons. The typical results of FD2 G technology on commercial units showed that it could produce clean diesel with a sulfur content of less than 10 μg/g and clean gasoline with a research octane number(RON) of up to 92. It would be contributed to the achievement of the maximum profit of a refinery, the FD2 G technology could provide a higher economic efficiency than the other diesel quality upgrading technology under the current gasoline and diesel price system.