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Catalytic performance of perovskite-like oxide doped cerium(La_(2-x)Ce_xCoO_(4±y)) as catalysts for dry reforming of methane

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Chinese Journal of Chemical Engineering 2019年第2期27卷 379-385页

作者： Yukun Bai Yuqi Wang Weijian Yuan Wen Sun Guoxia Zhang Lan Zheng Xiaolong Han Lifa Zhou School of Chemical Engineering Northwest University Shaanxi Provincial Institute of Energy Resources & Chemical Engineering

A series of oxides(La_(2-x)Ce_xCoO_(4±y)) with perovskite-like structure were prepared by the Pechini sol–gel method for dry reforming of methane reaction(DRM). The prepared catalysts were characterized by BET, XRD,TGA, H_2-TPR and SEM. Experimental results indicate that the addition of Ce can impact both sample morphology and catalytic performance significantly compared with La_2CoO_4 catalyst, and LaCeCoO_4 presented the highest catalytic ability among all the samples. The Ce addition tends to increase the specific surface area of La_(2-x)Ce_xCoO_(4±y)from 0.2 to 8.5 m^2·g^(-1), suggesting that LaCeCoO_4 catalyst contained more well-dispersed active sites and more space to reaction. Moreover, the catalytic performance and anti-coking ability were substantially improved after Ce addition during DRM, which may be attributed to the decrease of LaCoO_3 particle size and growth of oxygen storage capacity, respectively.

关键词： Perovskite-like La2-xCexCoO4±y Methane dry reforming Cerium Syngas

Synthesis of Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ) and its catalytic performance on dry methane reforming

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Journal of Rare Earths 2019年第6期37卷 585-593页

作者： Dingwen Kang Jie Yu Wenhui Ma Min Zheng Yunfei He Pengfei Li Faculty of Metallurgical and Energy Engineering Kunming University of Science and Technology National Engineering Laboratory for Vacuum Metallurgy Kunming University of Science and Technology

In this study,Cu/Ni-La_(0.7)Sr_(0.3)Cr_(0.5)Mn_(0.5)O_(3-δ)(LSCM) catalysts were synthesized via the citric acid-nitrate process(CNP) and chemical co-precipitation. The catalytic performance of Cu/Ni-LSCM catalysts on dry methane reforming was evaluated in a fixed-bed reactor at 550/650 ℃ and atmosphere pressure. Cu/Ni loading was investigated as an influencing factor, which led to 5 cases of samples according to the different Cu/Ni mass ratios. The catalysts were characterized by X-ray diffraction(XRD), field emissionscanning electron microscope(FE-SEM), Brunauer-Emmett-Teller(BET) measurement, X-ray photoelectron spectroscopy(XPS), hydrogen-based temperature-programmed reduction(H_2-TPR) and thermos gravimetric analyzer(TGA). The results show that the methane conversion increases, the resistance against metal sintering increases and the carbon deposition drops after the copper is introduced. This optimum performance can be obtained under Case 3(Cu:Ni:LSCM = 1:3:6 in mass ratio).

关键词： Cu/Ni-LSCM Characterization dry methane reforming Carbon deposition Rare earths

Selection and Evaluation of dry and Isentropic Organic Working Fluids Used in Organic Rankine Cycle Based on the Turning Point on Their Saturated Vapor Curves

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Journal of Thermal Science 2019年第4期28卷 643-658页

作者： ZHANG Xinxin ZHANG Congtian HE Maogang WANG Jingfu MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation College of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China Beijing Key Laboratory of Heat Transfer and Energy Conversion College of Environmental and Energy EngineeringBeijing University of TechnologyBeijing 100124China MOE Key Laboratory of Thermo-Fluid Science and Engineering School of Energy and Power EngineeringXi'an Jiaotong UniversityXi’an 710049China

The organic Rankine cycle(ORC)is a popular technique used in the utilization of low-grade thermal *** wet,dry,and isentropic organic working fluids,the latter two types are more appropriate for ORC *** this paper,the definition of turning point on saturated vapor curve of dry fluid and isentropic fluid was given according to the shape of the saturated curve of working fluids in a T-s *** this basis,the model of near-critical region triangle was *** this model,the thermodynamic performance of 57 kinds of dry and isentropic organic working fluids in ORC was *** performance includes the relation between turning point temperature and cycle thermal efficiency,the relation between near-critical region triangle area and cycle thermal efficiency,the relation between near-critical region triangle area and exergy at turning point temperature,the relation between near-critical region triangle area and reciprocal value of slope of saturated vapor ***,working fluid selection was also conducted in terms of heat source *** was found through theoretical analysis results that the popular R123 is an acceptable choice especially for the utilization of closed type heat *** it will be phased out in near future,then cis-butene,butane,trans-butene,and isobutene are worth studying as its *** is worthy of attention and further research and it can be a good choice for utilization of open type heat source.

关键词： dry fluid isentropic fluid turning point saturated vapor curve near-critical region triangle Organic Rankine Cycle

Microstructure and dry wear properties of Ti-Nb alloys for dental prostheses

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中国有色金属学会会刊：英文版 2009年第S3期19卷 639-644页

作者：徐丽娟肖树龙田竟陈玉勇黄玉东 School of Materials Science and Engineering Harbin Institute of Technology School of Chemical Engineering and Technology Harbin Institute of Technology

The microstructure and properties of a series of binary Ti-Nb alloys for dental prostheses with niobium contents ranging from 5% to 20% were investigated. The experimental results indicate that the crystal structure and morphology of Ti-Nb alloys are sensitive to their niobium contents. When Nb content is 5%, the acicular α crystal grain is observed. When Nb content is 10%, the coarse equiaxed crystal grain and the fine, acicular α crystal grain are observed. When Nb content is 15%, only the α equiaxed crystal grain is observed. When the alloy contains 20%Nb, the equiaxed and dendritic α crystal grain are observed. For Ti-Nb alloys, the increase of Nb content modifies the microstructure of Ti-Nb alloys significantly and decreases their compression elastic modulus, in which Ti-20Nb alloy shows the largest compression strength and Ti-5Nb alloy shows the best plasticity. The dry wear resistance of Ti-Nb alloys against Gr15 ball was investigated on CJS111A ball-disk wear instrument. For Ti-Nb alloys, Ti-10Nb alloy shows a smallest steady friction coefficient, Ti-5Nb alloy shows the smallest wear depth and best wear resistance, and Ti-15Nb alloy shows the largest wear depth and worst wear resistance. The phenomenon of furrow cut happens and furrows form during wear tests.

关键词： Ti-Nb alloy microstructure dry wear resistance dental prostheses material

Impact of Mid-and Upper-Level dry Air on Tropical Cyclone Genesis and Intensification:A Modeling Study of Durian(2001)

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Advances in Atmospheric Sciences 2018年第12期35卷 1505-1521页

作者： Yaping WANG Yongjie HUANG Xiaopeng CUI Key Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science & TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China

The impact of mid-and upper-level dry air,represented by low relative humidity(RH)values,on the genesis of tropical cyclone(TC)Durian(2001)in the South China Sea was investigated by a series of numerical experiments using the Weather Research and Forecasting *** mid-level RH was lowered in different regions relative to TC Durian(2001)’s genesis *** suggest that the location of dry air was important to Durian(2001)’s genesis and *** rapid development of the TC was accompanied by sustained near-saturated mid-and upper-level air,whereas low humidity decelerated its *** vapor budget analysis showed that moisture at mid and upper levels was mainly supplied by the vertical convergence of moisture flux and the divergence terms,and consumed by the condensation *** horizontal convergence of moisture flux term supplied moisture in the air moistening process but consumed moisture in the air drying *** a dryer mid-and upper-level environment,convective and stratiform precipitation were both *** upward mass fluxes and the diabatic heating rates associated with these two precipitation types were also ***,convection played the dominant role,since the impact of the stratiform process on vertical mass transportation and diabatic heating was much *** vorticity budget showed that the negative vorticity convergence term,which was closely related to the inhibited convection,caused the vorticity to decrease above the lower troposphere in a dryer *** negative vorticity tendency is suggested to slow down the vertical coherence and the development rate of TCs.

关键词： tropical cyclone formation mid-and upper-level dry air WRF water vapor budget convective and stratiform precipitation

Weed growth, herbicide efficacy, and rice productivity in dry seeded paddy field under different wheat stubble management methods

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Journal of Integrative Agriculture 2019年第4期18卷 907-926页

作者： Muhammad Zia-Ul-Haq Abdul Khaliq Qiang Sheng Amar Matloob Saddam Hussain Saba Fatima Zeshan Aslam Department of Agronomy University of AgricultureFaisalabad Weed Research Laboratory College of Life Sciences Nanjing Agricultural University Department of Agronomy Muhammad Nawaz Shareef University of Agriculture Department of Economics National College of Business Administration and Economics Pesticide Residue Laboratory Kala Shah Kaku Institute of Soil Chemistry and Environmental Sciences Government of Punjab

To ascertain the influence of wheat stubble management options and chemical weed control methods on weed growth and productivity of dry direct-seeded fine rice, a two years' field study was undertaken at the Agronomic Research Farm, University of Agriculture, Faisalabad, Pakistan in 2013 and 2014. Different wheat stubble management methods, viz., incorporation, burning and retention were executed during seed-bed preparation. While, herbicide treatments comprised of a weed check, weed free, pendimethalin followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl, and bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl. Results revealed that weed control efficacy of both herbicide treatments ranged from 84 to 94%. Herbicide treatments significantly reduced weed density(88–90%) and dry weight(86–88%), while improved the rice growth attributes compared with weed check. Application of bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention recorded 226 and 273% increase in kernel yield over weedy check in 2013 and 2014, respectively. In stubble incorporation, pendimethalin followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl was more effective in increasing(256–293%) rice yields over weedy check. Among different treatment combinations, the maximum net benefits(1 397.49^(–1) 472.22 USD ha^(–1)), net returns(636–700 USD ha^(–1)), benefit cost ratio(1.77^(–1).83) and marginal rate of return(2 187–2 330%) were recorded with the application of bispyribac sodium followed by fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention. In crux, application of bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention is efficient approach to control weeds, and get maximum rice productivity and net economic returns under dry seeded system.

关键词： herbicide mixture weedy check stubble management weeds density and dry weight DSR

Wear-resistant coating spraying technique for wear-proofing cover of coke dry quenching furnace

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Journal of Iron and Steel Research International 2019年第2期26卷 123-129页

作者： Zhang-fu Yuan Shan-shan Xie Xiang-tao Yu Jian Liu Ping Du Zhi-hua Li Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Jiangsu Shagang Iron and Steel Research Institute Co. Ltd.Suzhou 215625JiangsuChina

During the operation of a coke dry quenching system of coking plant, wear-proofing cover of the boiler was seriously eroded, and even the ceiling tube of the boiler was worn and torn. Thus, attentions were paid to the research, development and application of the wear-resistant coating spraying technique for wear-proofing cover of the coke dry quenching furnace. The Cr3C2–NiCr coatings for wear-proofing cover were fabricated via supersonic arc spraying process, and the residual coating of wear-proofing cover would be sampled for being analyzed after two years. The coating presents a dense microstructure with few pores and micro-cracks (the porosity is 4.65%). After thermal spraying of the wear-proofing cover, the hardness and the wear resistance of the surface are improved. The remaining coating is continuous and compact, with an average thickness of about 147μm. Transverse micro-cracks parallel to the spreading direction of the coating surface are displayed on different areas of the coating, which demonstrates its serious erosion wear effect. The main chemical component of white zone is Fe–18Cr–Ni. The Cr level of light gray phase is about 77.57 wt.% and the O level is 22.43 wt.%. And the main chemical components of dark gray phase are C, O, Al, Si and Ca. X-ray diffraction patterns were adopted to implement phase analysis on the surface of coating sample, which indicated that the coating was composed of a large amount of Cr3O2 and a small amount of metal Cr.

关键词： Coke dry quenching Wear-proofing cover Thermal spraying technique Coating property Cr3C2-NiCr coating

Syngas production by dry reforming of the mixture of glycerol and ethanol with CaCO3

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Journal of Energy Chemistry 2020年第4期29卷 90-97页

作者： Chengxiong Dang Shijie Wu Guangxing Yang Yonghai Cao Hongjuan Wang Feng Peng Hao Yu School of Chemistry and Chemical Engineering Guangzhou UniversityGuangzhou 510006GuangdongChina School of Chemistry and Chemical Engineering Guangdong Provincial Key Lab of Green Chemical Product TechnologySouth China University of TechnologyGuangzhou 510640GuangdongChina

The reduction of CO2 emission is crucial for the mitigation of climate change.A considerable amount of industrial CO2 can be absorbed in the form of carbonates through high-temperature sorption *** this regard,the efficient conversion of carbonates to value-added products will provide an economically viable method for the sustainable usage of carbon ***,we report a promising solution involving the use of a glycerol and ethanol mixture as a hydrogen donor in the dry reforming process with CaCO3 to produce syngas.A series of metal active components,including Ni,Fe,Co,Cu,Pt,Pd,Ru,and Rh,was used to promote this *** showed comparable performance with that of Pd,but outperformed Co,Fe,Cu,Rh,Ru,and *** 100%conversion of glycerol and ethanol,~92%selectivity of synthesis gas(H2 and CO),and a H2/CO ratio of^1.2 were achieved over CaCO3 containing10 wt%Ni(10Ni-CaCO3).Meanwhile,the CO2 concentration was less than 5 vol%,indicating that most of the CO2 captured by the carbonate can be transformed into chemicals;however,they cannot simply be *** CO2 released from the decomposition of CaCO3 not only adjusted the ratio of H2 to CO but also eliminated cokes to guarantee the CO2 absorption-conversion cyclic stability in the absence of steam and at high temperatures.

关键词： Glycerol Ethanol CaCO3 dry reforming Syngas

Three-dimensional numerical simulation of soft/hard composite-coated textured tools in dry turning of AISI 1045 steel

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Advances in Manufacturing 2019年第2期7卷 133-141页

作者： Yun-Song Lian Chen-Liang Mu Ming Liu Hui-Feng Chen Bin Yao Department of Mechanical and Electrical Engineering Xiamen University Xiamen 361102 Fujian People's Republic of China

A structural model of a soft/hard compositecoated textured (SHCCT) tool was proposed and substantiated by a three-dimensional numerical simulation. Its dry turning performance as applied to AISI-1045 steel was analyzed via three-factor five-level orthogonal experiments for different coating parameters, including coating thickness, coating material, and thickness ratio of the soft and hard coatings. In addition, the cutting performance of the proposed SHCCT tool was compared with those of uncoated non-textured, coated non?textured, and uncoated textured tools, and its superiority was proved by the significant reductions in the cutting force, and specifically, the cutting temperature. The optimal results were provided by the SHCCT tool with a WS2/ZrN soft/hard composite coating, a 0.9:0.1 thickness ratio of the above ingredients, and a total coating thickness of 0.5 μm.

关键词： dry cutting performance Soft/hard composite-coated textured (SHCCT) tool Finite element analysis Coating parameters Cemented carbide