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Synthesis and Molecular Structure of Acetic Acid-3,5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin-2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester

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Chinese Journal of Structural Chemistry 2006年第8期25卷 1014-1018页

作者： WEI Hui-Qin ZENG Run-sheng WU Gui-ping wang Bao-An ZOU Jian-ping Key Laboratory of Organic Synthesis of Jiangsu Province College ofChemistry and Chemical Engineering Suzhou University Suzhou 215123 China

The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-（4-quinoxalin- 2-yl-phenoxy）-tetrahydro-pyran-4-yl-ester 8 （C28H28N2O10, Mr = 552.54）, has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, a = 10.060（8）, b = 5.648（4）, c = 24.11（2）A, β = 91.078（10）°, Z = 2, V= 1369.9（19）A^3, Dc = 1.339 g/cm^3,μ（MoKa） = 1.03 cm^-1, F（000） = 580.00, T =. 193.1 Kx-9 θmax = 25.03, （△/σ）max = 0.0000, Flack = -0.0（24）, the final R = 0.0680 and wR = 0.140 （w = 1/[0.0016Fo^2 ＋ 1.00000（Fo^2）]/（4Fo^2）） for 3126 observed reflections （1 〉 20（/））. The pyranoid ring adopts chair conformation in the sugar moiety, and all of the acetyl groups are in the e bond of the pyranoid ring, so the sugar moiety is very stable.

关键词： acetic acid-3 5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin-2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester synthesis crystal structure

An in situ infrared study of dimethyl carbonate synthesis from carbon dioxide and methanol over well-shaped CeO2

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Chinese Chemical Letters 2017年第1期28卷 65-69页

作者： shu-yang zhao sheng-ping wang yu-jun zhao xin-bin ma key laboratory for green chemical technology school of chemical engineering and technologytianjin universitycollaborative innovation center of chemical science and engineeringTianjin 300072China

The mechanism of dimethyl carbonate（DMC） formation from CO2 and methanol is investigated using three well-shaped CeO2 catalysts, nanorod, nanocube and octahedron, which are packed with different crystal planes. In situ Fourier Transform Infrared Spectroscopy（FTIR） is employed to probe each reaction step in the DMC synthesis. The number of –OH groups and the species of CO2 adsorptions on ceria surface have significant influence on the activity of ceria with different morphologies. Rod-ceria has favorable catalytic activity because of the large amount of –OH groups and the formation of bidentate carbonate species.

关键词： Dimethyl carbonate CeO2 -OH Bidentate carbonate Crystal planes

Preparation of Diphenyl Oxalate from Transesterification of Dimethyl Oxalate with Phenol over TS-1 Catalyst

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Chinese Chemical Letters 2003年第5期14卷 461-464页

作者： Xin Bin MA sheng ping wang Hong Li GUO Gen Hui XU State Key Laboratory of C1 Chemistry and Technology School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072

Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalate and methylphenyl oxalate compared with other homogeneous catalysts. Lewis acid sites on TS-1 catalyst were the active sites for transesterification of dimethyl oxalate with phenol. The high selectivity was closely related to the weak acid sites over TS-1.

关键词： Diphenyl oxalate transesterification dimethyl oxalate weak acid sites TS-1.

Effects of potassium promoter on the performance of PdCl_2–CuCl_2/AC catalysts for the synthesis of dimethyl carbonate from CO and methyl nitrite

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Chinese Chemical Letters 2015年第11期26卷 1359-1363页

作者： sheng-ping wang Wei Li Yuan-Yuan Dong Yu-Jun Zhao Xin-Bin Ma Key Laboratory for Green Chemical Technology School of Chemical Engineering and Technology Tianjin University Collaborative Innovation Center of Chemical Science and Engineering

The effect of potassium （K） promoter on the catalytic performance of activated carbon （AC） supported Wacker-type catalysts （PdCl2-CuCl2/AC） for the synthesis of dimethyl carbonate （DMC） from CO and methyl nitrite （MN） was investigated by means of N2 adsorption, H2-temperature-programmed reduction （H2-TPR）, and X-ray photoelectron spectroscopy （XPS）. The experimental results showed that the space time yield of DMC on Wacker-type catalysts with different K promoters ranked in the following order： KCI 〉 KOH 〉 CH3COOK 〉 K2CO3. Especially, the addition of KCI significantly improved the catalytic activities of PdCl2-CuCl2/AC catalyst for DMC synthesis from CO and MN. N2 adsorption data indicated that the addition of K promoters did not change the textural properties of Wacker-type catalysts greatly. H2-TPR and XPS results demonstrated that the existence of KCI promoted the reducibility of Cu2＋ species and increased the proportion of Cu2＋ species on catalyst surface, which is favorable for oxidizing Pd0 to active Pd2＋. Further, the addition of KCI benefited the reactivity of PdCI2- CuCl2/AC catalwt for DMC synthesis from CO and MN.

关键词： Dimethyl carbonateWacker-type catalystActivated carbonPotassium promoterMethyl nitrite

Novel fabrication of copper oxides on AC and its enhanced catalytic performance on oxidative carbonylation of methanol

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Chinese Chemical Letters 2017年第1期28卷 70-74页

作者： Ke Shi Shou-Ying Huang Zhong-Yao Zhang sheng-ping wang Xin-Bin Ma Key Laboratory for Green Chemical Technology School of Chemical Engineering and Technology Tianjin University Collaborative Innovation Center of Chemical Science and Engineering Tianjin 300072 China

Copper oxides（CuOx） nanoparticles dispersed on activated carbon（AC） were prepared by using vaporphase methanol as the reducing agent. The CuOx/AC as prepared exhibited an enhanced catalytic activity in oxidative carbonylation of methanol to dimethyl carbonate（DMC）. The catalytic performance was significantly influenced by reduction conditions including temperature and time. With the similar selectivity of DMC, the space time yield（STY） under optimal reduction conditions reached up to 408 mg g^-1h^-1, which is superior to conventional methods such as thermolysis and solvothermal reduction. Based on the characterization results of XRD, TEM and XPS, the good copper dispersion and high Cu^＋ content obtained by vapor-phase methanol reduction were mainly responsible for the high catalytic activity.

关键词： Dimethyl carbonate Oxidative carbonylation Copper oxides Vapor-phase methanol reduction Activated carbon

Enhancements of dimethyl carbonate synthesis from methanol and carbon dioxide:The in situ hydrolysis of 2-cyanopyridine and crystal face effect of ceria

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Chinese Chemical Letters 2015年第9期26卷 1096-1100页

作者： sheng-ping wang Jing-Jie Zhou Shu-Yang Zhao Yu-Jun Zhao Xin-Bin Ma Key Laboratory for Green Chemical Technology School of Chemical Engineering and TechnologyCollaborative Innovation Center of Chemical Science and EngineeringTianjin University

This paper describes the effect of the in situ hydrolysis of 2-cyanopyridine and its derivatives on the synthesis of dimethyl carbonate（DMC） from CO2 and methanol over *** the highest electronic charge number of the carbon in the cyanogroup,is the most effective agent to accelerate the desired reaction by a decrease of ***2（110） planes are active for the hydrolysis of 2-cyanopyridine,further enhancing the DMC formation by in situ removal of water *** DMC yield is improved drastically up to 378.5 mmol g cat^-1 from 12.8 mmol g cat^-1 with the in situ hydrolysis of 2-cyanopyridine over rod-CeO2（1 1 0） catalyst.

关键词： Dimethyl carbonate CeO2 Hydrolysis 2-Cyanopyridine Crystal face

A method for support stiffness failure identification in a steel spring floating slab track of urban railway: a case study in China

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 206-222页

作者： Junyuan ZHENG Caiyou ZHAO Duojia SHI ping wang Jian wang Bolong JIANG Xi sheng Key Laboratoryof High-speed Railway Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 60031China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China 01 DYNA(Qingdao)Test&Data Co. Ltd.Qingdao 266000China Rail Transit Digital Construction and Measurement Technology National Engineering Research Center China Railway Design CorporationTianjin300308China Institute of Urban Smart Transportation&Safety Maintenance Shenzhen UniversityShenzhen 518060China

The extensive use of steel spring floating slab tracks has effectively addressed the challenge of alleviating the environmental vibrations induced by urban rail transit ***,under the combined action of train dynamic loads and complex environmental factors,problems,such as the fracture of steel spring vibration isolators and suspension vibrations induced by the uneven settlement of the base,often *** failure of isolator support stiffness is often hidden in its early stages and is challenging to identify by conventional detection *** the same time,it will aggravate the wheel-rail interaction,accelerate the deterioration of track structure,and even affect the driving *** study first establishes a detailed coupled train-floating slab track-foundation analytical *** the influence of the vibration isolator support stiffness failure on the dynamic indices of the floating slab track system response is analyzed.A set of defect identification methods that can detect the number of failed steel springs,severity of damage,and their location is ***,an intelligent monitoring system for support stiffness of floating slab track is built by combining the density-based spatial clustering of applications with noise algorithm and statistical data analysis and is applied to a rail line in southern *** a three-year monitoring campaign,a suspension failure and a fracture of a steel spring were each successfully detected and detailed failure information was *** investigation results were consistent with the damage identification *** repair,the track structure dynamic response returned to the average pre-damage level and further deterioration had been *** proposed damage identification methods and monitoring system provide an approach for intelligent identification of track structure support stiffness failures.

关键词： Floating slab track Support stiffness Detailed analytical model Failure identification Monitoring system

Viscosity and structure of CaO-BaO-SiO_(2)-Al_(2)O_(3)-based mold slags for continuous casting of high titanium steel with different Tio2 absorption

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Journal of Iron and Steel Research International 2024年第8期31卷 1936-1946页

作者： Ya-tao Cui Xue-you wang Xu-bin Zhang Qiang-qiang wang sheng-ping He College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The effect of TiO_(2) absorption into two different CaO-BaO-SiO_(2)-Al_(2)O_(3)-based mold slags from the steel plant on the viscosity,melting performance and microstructure of slags was investigated through the measurement of the viscosity-temperature relationship,melting temperature and Raman *** parameter of the number of non-bridging oxygen per tetrahedrally-coordinated atom(NBO/T)was also calculated to explain the microstructure variation of molten slags with different TiO_(2) *** variation of the actual slag consumption and the depth of the liquid slag in mold was explained through the comparison of the viscosity and the melting temperature of two different *** viscosity of mold slags(basicity=0.6)decreased from 1.1 to 0.68 Pa s with the increase in the Ti0_(2) absorption from 0 to 10%,while that of slags(basicity=0.7)decreased from 0.76 to 0.56 Pa s with the Ti0_(2) absorption from 0 to 6%.The activation energy of both two groups of slags had the tendency to decrease with the increasing TiO_(2) *** network structure of both two groups of slags measured by the Raman spectra showed that the fraction of complex structure units(Q^(1),Q^(2),Q^(3) and A1-O-Al)decreased and simple structure units(Al-O-and Q^(0))increased with the increase in TiO_(2) ***/T also increased with the increase in the TiO2 absorption,indicating that the absorption of TiO_(2) into slags resulted in the destruction of silicate/aluminate ***,the absorption of TiO_(2) into the current CaO-BaO-SiO_(2)-Al_(2)O_(3) mold slags decreased the degree of polymerization of these slags and then led to the decrease of viscosity.

关键词： Mold slag Viscosity Melting temperature Slag consumption Liquid slag depth Structure

Highly active Pd-Fe/α-Al_(2)O_(3) catalyst with the bayberry tannin as chelating promoter for CO oxidative coupling to diethyl oxalate

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Chinese Chemical Letters 2021年第2期32卷 796-800页

作者： Wei-Chao Xing Ji-Min An Jing Lv Faisal Irshad Yu-Jun Zhao sheng-ping wang Xin-Bin Ma Key Laboratory for Green Chemical Technology School of Chemical Engineering and TechnologyTianjin UniversityCollaborative Innovation Center of Chemical Science and EngineeringTianjin 300072China

A novel Pd-Fe/α-Al_(2)O_(3) catalyst was synthesized by incipient-wetness impregnation method with bayberry tannin as chelating promoter and commercial hollow column Raschig ring a-Al_(2)O_(3) as support for the synthesis of diethyl oxalate from CO and ethyl nitrite.A variety of characterization techniques including N2 physical adsorption,optical microscopy,scanning electron microscopy and energy dispersive system(SEM-EDS),inductively coupled plasma optical emission spectroscopy(ICP-OES),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),were employed to explore the relationship between the physicochemical properties and activity of *** indicated that a large number of phenolic hydroxyl groups in bayberry tannin can efficiently anchor the active component Pd,reduce the particle size and make the active Pd as a multi-ring distribution on the commercial a-Al2O3 suppo rt,which we re beneficial to improve the catalytic activity for the production of diethyl oxalate from CO and ethyl nitrite.0.3 wts Pd-Fe/α-Al_(2)O_(3) showed excelle nt catalytic activity and selectivity in a continuous flow,fixed-bed reactor with the loading amount of 10 mL catalysts,Under the mild reaction conditions,the space-time yield of diethyl oxalate was 978 g L^(-1) h^(-1) and CO conversion was 44% with the selectivity to diethyl oxalate of 95.5%.

关键词： Bayberry tannin Diethyl oxalate Phenolic hydroxyl groups Ethyl nitrite Pd-Fe/α-Al_(2)O_(3)