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Tartaric acid-assisted co-precipitation synthesis of Er^(3+)-doped Lu_2O_3 nanopowders

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Chinese Chemical Letters 2012年第11期23卷 1299-1302页

作者： Neng Li Wang Xi Yan Zhang peng he Wang School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun 130022China

Erbium-doped lutetia nanopowders were synthesized by a novel co-precipitation method using tartaric acid as precipitant. The properties of the samples were investigated by Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD）, TG-DSC, field emission scanning electron microscopy （FE-SEM）, and upconversion luminescence analysis. Pure cubic Lu2Oa nanopowders were directly obtained when the precursor was calcined at 800 ℃ for 2 h, the samples showed strong upconversion luminescence under excitation of 980 nm laser diode.

关键词： Co-precipitation Tartaric acid Erbium-doped lutetia Upconversion

Hybrid reconstruction algorithm for computed tomography based on diagonal total variation

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Nuclear Science and Techniques 2018年第3期29卷 172-180页

作者： Lu-Zhen Deng peng he Shang-Hai Jiang Mian-Yi Chen Biao Wei peng Feng Key Laboratory of Optoelectronic Technology and Systems Ministry of Education Chongqing University Department of Radiation Physics The University of Texas MD Anderson Cancer Center ICT NDT Engineering Research Center Ministry of Education Chongqing University Collaborative Innovation Center for Brain Science Chongqing University

Inspired by total variation(TV), this paper represents a new iterative algorithm based on diagonal total variation(DTV) to address the computed tomography image reconstruction problem. To improve the quality of a reconstructed image, we used DTV to sparsely represent images when iterative convergence of the reconstructed algorithm with TV-constraint had no effect during the reconstruction process. To investigate our proposed algorithm, the numerical and experimental studies were performed, and rootmean-square error(RMSE) and structure similarity(SSIM)were used to evaluate the reconstructed image quality. The results demonstrated that the proposed method could effectively reduce noise, suppress artifacts, and reconstruct highquality image from incomplete projection data.

关键词： Computed tomography (CT) Sparse-view reconstruction Diagonal total variation (DTV) Compressive sensing (CS)

Vertically grown MoS_(2)nanosheets on graphene with defect-rich structure for efficient sodium storage

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Rare Metals 2024年第3期43卷 1062-1071页

作者： Ying Wang Jia-peng he Han-Qing Pan Qing-peng Wang Lei Zhang Yong-Chang Liu Qing-Hong Wang School of Chemistry&Materials Science Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional MaterialsJiangsu Normal UniversityXuzhou221116China Institute of Biopharmaceutical Research Liaocheng UniversityLiaocheng252059China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyState Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing100083China Centre for Catalysis and Clean Energy Gold Coast CampusGriffith UniversityGold CoastQLD4222Australia

The synthesis of a perpendicular growth structure of MoS_(2)nanosheets on graphene for efficient sodium storage is challenging yet ideal due to the benefits of open ion diffusion channels and high electronic *** this study,we have successfully fabricated a novel structure of vertical MoS_(2)nanosheets on graphene,with ZnS nanoparticles serving as bonding points(MoS_(2)/ZnS/G),through a facile hydrothermal *** the synthesis process,Zn^(2+)not only acts as a landing site for the vertical growth of MoS_(2)nanosheets but also triggers the formation of a defect-rich structure in the final *** unique architecture of MoS_(2)/ZnS/G effectively combines the advantages of a vertically aligned geometry and a defectrich structure for energy *** resulting structure displays shortened transport paths for electrons/ions,enhanced conductivity,improved structural integrity,and an increased number of active sites for promising electrochemical *** expected,when used as anode for sodium-ion batteries,the as-synthesize d MoS_(2)/ZnS/G exhibits excellent rate capability(high capacity of 298 mAh·g^(-1)at 5 A·g^(-1))and good cycling stability(a capacity decay of 0.056%per cycle after 500 cycles at 1 A·g^(-1)).According to the kinetic investigations,the electrochemical process of the MoS_(2)/ZnS/G sample is primarily governe d by a pseudocapacitive behavior,which enhances the charge/discharge kinetics and allows the MoS_(2)/ZnS/G structure to remain intact during cycling.

关键词： MoS_(2) Perpendicular growth Graphene Sodium storage Electrochemical performance

Catalytic oxidation of benzene over nanostructured porous Co_3O_4-CeO_2 composite catalysts

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Journal of Environmental Sciences 2011年第12期23卷 2078-2086页

作者： Chunyan Ma Zhen Mu Chi he peng Li Jinjun Li Zhengping Hao Department of Environmental Nano-materials Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Mesostructured Co3O4-CeO2 composite was found to be an effective catalytic material for the complete oxidation of benzene. The Co3O4-CeO2 catalysts with different Co/Ce ratios （mol/mol） were prepared via the nanocasting method and the mesostructure was replicated from two-dimensional （2D） hexagonal SBA-15 and three-dimensional （3D） cubic KIT-6 silicas, respectively. All the obtained Co3O4-CeO2 catalysts exhibited the similar symmetry with the parent silicas and well ordered mesostructures. The Co3O4- CeO2 catalysts with 2D mesostructure showed lower catalytic activities than the corresponding 3D materials. The Co3O4-CeO2 catalyst nanocasted from KIT-6 and with the Co/Ce ratio of 16/1 possessed the best catalytic benzene oxidation activity due to larger quantities of surface hydroxyl groups and surface oxygenated species. The mesostructured Co3O4-CeO2 material thus shows great potential as a promising eco-environmental catalyst for benzene effective elimination.

关键词： benzene elimination nanocasting mesoporous Co3O4-CeO2 2D/3D structural Co/Ce ratios

An efficient green route for hexamethylene-1,6-diisocyanate synthesis by thermal decomposition of hexamethylene-1,6-dicarbamate over Co3O4/ZSM-5 catalyst： An indirect utilization of CO2

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Chinese Journal of Chemical Engineering 2017年第12期25卷 1760-1770页

作者： Muhammad Ammar Yan Cao peng he Liguo Wang Jiaqiang Chen Huiquan Li Key Laboratory of Green Process and Engineering National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Engineering CAS Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

The utilization of CO2 as raw material for chemical synthesis has the potential for substantial economic and green benefits. Thermal decomposition of hexamethylene-1,6-dicarbamate （HDC） is a promising approach for indirect utilization of CO2 to produce hexamethylene-1,6-diisocyanate （HDI）. In this work, a green route was developed for the synthesis of HD1 by thermal decomposition of HDC over Co3O4/ZSM-5 catalyst, using chlorobenzene as low boiling point solvent. Different metal oxide supported catalysts were prepared by incipient wetness impregnation （IWI）, PEG-additive （PEG） and deposition precipitation with ammonia evaporation （DP） methods. Their catalytic performances for the thermal decomposition of HDC were tested. The catalyst screening results showed that Co3O4/ZSM-525 catalysts prepared by different methods showed different performances in the order of Co3O4/ZSM-5 25（PEG）〉 Co3O4/ZSM-525（IWI）〉 Co3O4/ZSM-525（DP）. The physicochemical properties of Co3O4/ZSM- 52s catalyst were characterized by XRD, FTIR, N2 adsorption-desorption measurements, NH3-TPD and XPS. The superior catalytic performance of Co3O4/ZSM-52S（PEG） catalyst was attributed to its relative surface content of Co3 ＋, surface lattice oxygen content and total acidity. Under the optimized reaction conditions： 6.5% HDC concentration in chlorobenzene, 1 wt% Co3O4/ZSM-525（PEG） catalyst, 250℃ temperature, 2.5 h time, 800 *** 1 nitrogen flow rate and 1.0 MPa pressure, the HDC conversion and HDI yield could reach 100% and 92.8% respectively. The Co3O4/ZSM-525（PEG） catalyst could be facilely separated from the reaction mixture, and reused without degradation in catalytic performance. Furthermore, a possible reaction mechanism was proposed based on the physicochemical properties of the Co3O4/ZSM-5 25 catalysts.

关键词： hexamethylene-1 6-dicarbamate (HDC)hexamethylene-1 6-diisocyanate (HDI) Thermal decomposition Co3O4/ZSM-5 heterogeneous catalyst

Microstructural Evolution and Mechanical Properties of Inconel 625 Alloy during Pulsed Plasma Arc Deposition Process

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Journal of Materials Science & Technology 2013年第5期29卷 480-488页

作者： Fujia Xu Yaohui Lv Yuxin Liu Fengyuan Shu peng he Binshi Xu State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering

Pulsed plasma arc deposition （PPAD）, which combines pulsed plasma cladding with rapid prototyping, is a promising technology for manufacturing near net shape components due to its superiority in cost and convenience of processing. In the present research, PPAD was successfully used to fabricate the Ni-based superalloy Inconel 625 components. The microstructures and mechanical properties of deposits were investigated by scanning electron microscopy （SEM）, optical microscopy （OM）, transmission electron microscopy （TEM） with energy dispersive spectrometer （EDS）, microhardness and tensile testers. It was found that the as-deposited structure exhibited homogenous columnar dendrite structure, which grew epitaxially along the deposition direction. Moreover, some intermetallic phases such as Laves phase, minor MC （NbC, TiC） carbides and needle-like δ-Ni3Nb were observed in y-Ni matrix. Precipitation mechanism and distribution characteristics of these intermetallic phases in the as-deposited 625 alloy sample were analyzed. In order to evaluate the mechanical properties of the deposits, microhardness was measured at various location （including transverse plane and longitudinal plane）. The results revealed hardness was in the range of 260- 285 HVo.2. In particular, microhardness at the interface region between two adjacent deposited layers was slightly higher than that at other regions due to highly refined structure and the disperse distribution of Laves particles. Finally, the influence of precipitation phases and fabrication strategies on the tensile properties of the as-deposited samples was investigated. The failure modes of the tensile specimens were analyzed with fractography.

关键词： Pulsed plasma arc deposition Inconel 625 components Microstructure Mechanical properties

Isobaric vapor–liquid equilibrium for binary system of aniline+methyl-N-phenyl carbamate

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Chinese Journal of Chemical Engineering 2016年第10期24卷 1470-1476页

作者： Yuqian Li Liguo Wang peng he Kelin Huang Huiquan Li Yan Cao Chemistry and Material Science College Guangxi Teacher Education University Key Laboratory of Green Process and Engineering National Engineering Laboratory for Hydrometallurgical Cleaner Production TechnologyInstitute of Process EngineeringChinese Academy of Sciences China Academy of Science & Technology Development Guangxi Branch

In this study,the quasi-static ebulliometric method was used to measure both of the vapor pressures of methyl N-phenyl carbamate(MPC),and the isobaric vapor–liquid equilibrium(VLE) data of the aniline and MPC binary *** measured vapor pressure data of MPC,at different temperature ranging from 369.60 to 389.54 K,fitted well with the Antoine *** VLE data for the aniline and MPC system at(2.00,4.00,6.00,7.00 and 8.00) k Pa were correlated by both of nonrandom two-liquid(NRTL) and Wilson *** parameters of the two models were obtained by regressing the experimental data,with the absolute temperature deviations of 0.54 K and 0.53 K,*** relative volatility of the binary system calculated was all far more than 1,which gives the conclusion that the high purity MPC can be separated from aniline and MPC binary system by rectification or distillation technology.

关键词： Vapor-liquid equilibrium Aniline Methyl N-phenyl carbamate NRTL Wilson

Non-phosgene synthesis of hexamethylene-1,6-diisocyanate from thermal decomposition of hexamethylene-1,6-dicarbamate over Zn–Co bimetallic supported ZSM-5 catalyst

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Chinese Journal of Chemical Engineering 2019年第3期27卷 549-555页

作者： Yan Cao Yafang Chi Ammar Muhammad peng he liguo Wang Huiquan Li CAS Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Engineering Chinese Academy of Sciences University of Chinese Academy of Sciences

A non-phosgene route for the synthesis of hexamethylene-1,6-diisocyanate(HDI) was developed via catalytic decomposition of hexamethylene-1,6-dicarbamate(HDC) over Zn–Co bi-metallic supported ZSM-5 *** catalyst was characterized by FTIR and XRD analyses. Three solvents dioctyl sebacate(DOS), dibutyl sebacate(DBS) and 1-butyl-3-methylimidazolium tetrafluoroborate(BMIMBF_4) were investigated and compared; DOS gave better performance. The catalytic performances for thermal decomposition of HDC to HDI using DOS as solvent were then investigated, and the results showed that, under the optimized reaction conditions, i.e.,10 wt%concentration of HDC in DOS, 250 °C temperature, 60 min reaction time, 83.8% yield of HDI had been achieved over Zn–Co/ZSM-5. Decomposition of the intermediate hexamethylene-1-carbamate-6-isocyanate(HMI) over Zn–Co/ZSM-5 in DOS solvent was further studied and the results indicated that yield of HDI from HMI reached to 69.6%(98.6% HDI selectively) at 270 °C, which further increased the yield of the total HDI(HDI_(tol)) to as high as 95.0%. Recycling of catalyst showed that HDI and HMI yield slightly decreased, and by-product yield increased after the catalyst was reused for 4 times. At last possible reaction mechanism was proposed.

关键词： Non-phosgene Thermal decomposition hexamethylene-1,6-diisocyanate hexamethylene-1,6-dicarbamate Bimetallic supported ZSM-5 catalyst

Synthesis of a novel Al foam with a periodic architecture by introducing hollow Al tubes and Al/Mg powders

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Journal of Materials Science & Technology 2023年第17期148卷 105-115页

作者： Zhigang Xu Dayong Shen Kai Wang peng he Jian Zhang Hao Zhang peng Cao Shangyu Huang Jian peng Qiang Shen Chuanbin Wang Lianmeng Zhang Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China State Key Lab of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Wuhan Second Ship Design and Research Institute Wuhan 430205China Department of Chemical and Materials Engineering University of AucklandPrivate Bag 92019Auckland 1142New Zealand

In this work,we synthesized a brand-new Al foam with a periodic structure via a simple powder metallurgical *** periodic architecture consists of both hierarchical porous and bi-directional composition-graded *** results show that the hierarchical porous material includes large pores on millimeter scale inheriting from the hollow structure of the Al tubes,and small pores on mi-crometer scale produced by the sintering of Al/Mg *** bi-directional Mg concentration-graded structure is formed in the tube walls due to the condensation of Mg vapor in the inner tube *** addition of Mg powders achieves excellent metallurgical bonding between the Al powders and the hollow tubes at 550℃.The plateau stress and energy absorption capacity of the Al foam in y-axis compression are significantly higher than that in the x-axis due to their anisotropic *** general,the Al foam with Mg addition presents the most superior compression performance,and we believe that our find-ings could open up a unique strategy for developing high-performance metallic foams with the periodic architecture involving both hierarchical porous and bi-directional graded structure.

关键词： Al foam Hollow Al tube Mg evaporation Bi-directional composition-graded structure Compression properties Energy absorbing performance