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Nanostructured Ni-MoCx:An efficient non-noble metal catalyst for the chemoselective hydrogenation of nitroaromatics

Nano Research 2023年第7期16卷 8919-8928页

作者： Yifei Zhang Zhiwen Li Jingjing Zhang Liangliang Xu zhong-kang han Alfons Baiker Gao Li Institute of Catalysis for Energy and Environment College of Chemistry and Chemical EngineeringShenyang Normal UniversityShenyang 110034China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China Department of Chemistry and Applied Biosciences Institute for Chemical and BioengineeringETH ZurichHönggerbergHClZurich CH-8093Switzerland University of Chinese Academy of Sciences Beijing 100049China

Catalysts for chemoselective hydrogenation are of vital importance for the synthesis of various important chemicals and *** we developed a simple method for preparing a highly efficient Ni-MoC_(x)nanocomposite catalyst via temperature-programmed carburization of a polyoxometalate precursor.X-ray diffraction(XRD),scanning transmission electron microscopy(STEM),X-ray photoelectron spectroscopy(XPS),and X-ray absorption spectroscopy(XAS)analyses indicate that the resulting mesoporous nanocomposite catalyst is made up of well-dispersed metallic nickel particles embedded in a MoC_(x)*** catalyst exhibits high activity and selectivity(>99%)in the hydrogenation of various substituted nitroaromatics to corresponding *** high efficiency is attributed to the intimate contact of the constituents favoring electron transfer and hydrogen *** is physisorbed on the carbide support and dissociates on the nickel particles,as evidenced by Mo K-edge X-ray absorption near-edge structure(XANES)spectra,density functional theory(DFT),and hydrogen-deuterium *** remarkable catalytic performance of the catalyst could be traced back to the synergistic interaction between the Ni particles and the carbide ***-situ infrared spectroscopy and DFT simulations indicated that the adsorption/activation of the nitro group is favored compared to that of other substituents at the aromatic *** recyclability tests,the Ni-MoC_(x)nanocomposite showed no significant loss of catalytic performance in seven consecutive runs,indicating its robust nature.

关键词： Ni-MoC_(x)nanocomposite carburization of polyoxometalate hydrogenation nitroaromatics synergistic effect

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Continuous dimethyl carbonate synthesis from CO_(2) and methanol over Bi_(x)Ce_(1-x)O_(δ) monoliths:Effect of bismuth doping on population of oxygen vacancies,activity,and reaction pathway

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Nano Research 2022年第2期15卷 1366-1374页

作者： Yongdong Chen Yue Li Wei Chen Wen Wu Xu zhong-kang han Ammara Waheed zhongbin Ye Gao Li Alfons Baiker College of Chemistry and Chemical Engineering Southwest Petroleum UniversityChengdu 610500China School of Physical Science and Technology Ningbo UniversityNingbo 315211China Center for Energy Science and Technology Skolkovo Institute of Science and TechnologySkolkovo Innovation CenterMoscow 143026Russia State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China ETH Zurich Department of Chemistry and Applied BiosciencesInstitute for Chemical and BioengineeringHonggerbergHClCH-8093 ZurichSwitzerland

We evaluated bismuth doped cerium oxide catalysts for the continuous synthesis of dimethyl carbonate(DMC)from methanol and carbon dioxide in the absence of a dehydrating ***_(x)Ce_(1-x)O_(δ)nanocomposites of various compositions(x=0.06-0.24)were coated on a ceramic honeycomb and their structural and catalytic properties were *** incorporation of Bi species into the CeO_(2) lattice facilitated controlling of the surface population of oxygen vacancies,which is shown to play a crucial role in the mechanism of this reaction and is an important parameter for the design of ceria-based *** DMC production rate of the Bi_(x)Ce_(1-x)O_(δ) catalysts was found to be strongly enhanced with increasing Ov *** concentration of oxygen vacancies exhibited a maximum for Bi_(0.12)Ce_(0.88)O_(δ),which afforded the highest DMC production ***-term tests showed stable activity and selectivity of this catalyst over 45 h on-stream at 140°C and a gas-hourly space velocity of 2,880 mL·g_(cat)^(-1)·h^(-1).In-situ modulation excitation diffuse reflection Fourier transform infrared spectroscopy and first-principle calculations indicate that the DMC synthesis occurs through reaction of a bidentate carbonate intermediate with the activated methoxy(-OCH_(3))*** activation of C0_(2) to form the bidentate carbonate intermediate on the oxygen vacancy sites is identified as highest energy barrier in the reaction pathway and thus is likely the rate-determining step.

关键词： dimethyl carbonate synthesis bismuth-cerium oxides monolithic catalyst oxygen vacancies reaction mechanism

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The medium-temperature dependence of jet transport coefficient in high-energy nucleus-nucleus collisions

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Nuclear Science and Techniques 2024年第7期35卷 173-191页

作者： Man Xie Qing-Fei han En-Ke Wang Ben-Wei Zhang han-zhong Zhang Key Laboratory of Atomic and Subatomic Structure and Quantum Control(MOE) Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of MatterInstitute of Quantum Matter South China Normal UniversityGuangzhou510006China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Guangdong Provincial Key Laboratory of Nuclear ScienceSouthern Nuclear Science Computing CenterSouth China Normal UniversityGuangzhou 510006China Key Laboratory of Quark and Lepton Physics(MOE)and Institute of Particle Physics Central China Normal UniversityWuhan430079China

The medium-temperature T dependence of the jet transport coefficient̂q was studied via the nuclear modification factor RAA(pT)and elliptical flow parameter v_(2)(pT)for large transverse momentum pT hadrons in high-energy nucleus-nucleus *** a next-to-leading-order perturbative QCD parton model for hard scatterings with modified fragmentation functions due to jet quenching controlled bŷq,we check the suppression and azimuthal anisotropy for large pT hadrons,and extract̂q by global fits to RAA(pT)and v_(2)(pT)data in A+A collisions at RHIC and LHC,*** numerical results from the best fits show that̂q∕T^(3) goes down with local medium-temperature T in the parton jet *** with the case of a constant̂q∕T^(3),the going-down T dependence of̂q∕T^(3) makes a hard parton jet to lose more energy near Tc and therefore strengthens the azimuthal anisotropy for large pT *** a result,v_(2)(pT)for large pT hadrons was enhanced by approximately 10%to better fit the data at RHIC/*** the first-order phase transition from QGP to the hadron phase and the additional energy loss in the hadron phase,v_(2)(pT)is again enhanced by 5-10%at RHIC/LHC.

关键词： Jet quenching Jet transport parameter Hadron suppression Elliptic flow coefficient Energy loss asymmetry

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Monocular Distance Estimated Based on PTZ Camera

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Computers, Materials & Continua 2024年第5期79卷 3417-3433页

作者： Qirui zhong Xiaogang Cheng Yuxin Song han Wang Bell Honors School Nanjing University of Posts and Telecommunications Nanjing210003China College of Telecommunications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing210003China College of Automation and College of Artificial Intelligence Nanjing University of Posts and TelecommunicationsNanjing210003China

This paper introduces an intelligent computational approach for extracting salient objects fromimages and estimatingtheir distance information with PTZ (Pan-Tilt-Zoom) cameras. PTZ cameras have found wide applications innumerous public places, serving various purposes such as public securitymanagement, natural disastermonitoring,and crisis alarms, particularly with the rapid development of Artificial Intelligence and global infrastructuralprojects. In this paper, we combine Gauss optical principles with the PTZ camera’s capabilities of horizontal andpitch rotation, as well as optical zoom, to estimate the distance of the *** present a novel monocular objectdistance estimation model based on the Focal Length-Target Pixel Size (FLTPS) relationship, achieving an accuracyrate of over 95% for objects within a 5 km range. The salient object extraction is achieved through a simplifiedconvolution kernel and the utilization of the object’s RGB features, which offer significantly faster computingspeeds compared to Convolutional Neural Networks (CNNs). Additionally, we introduce the dark channel beforethe fog removal algorithm, resulting in a 20 dB increase in image definition, which significantly benefits distanceestimation. Our system offers the advantages of stability and low device load, making it an asset for public securityaffairs and providing a reference point for future developments in surveillance hardware.

关键词： Public security location information PTZ camera image processing

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Carbon efficiency modeling and optimization of solar-powered cellular networks

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Science China(Information Sciences) 2024年第5期67卷 228-243页

作者： Yuxi ZHAO Xiaohu GE Wen YAN Tao han Yi zhong School of Electronic Information and Communications Huazhong University of Science and Technology Huawei Technology Co. Ltd.

As wireless communication traffic experiences rapid growth, the carbon emissions caused by the communication industry are also on the rise. To achieve “carbon neutrality”, researchers are considering the use of renewable energy sources to power cellular networks, thereby reducing carbon emissions. However, a challenge arises when using renewable energy, specifically owing to the unpredictable nature of both the energy consumption of the cellular network and the power generation from renewable sources. This inconsistency results in low renewable energy utilization and reduced carbon efficiency. Herein, we construct a carbon efficiency model of solar-powered cellular networks using practical data from solar radiation. We propose a mechanism that alternately optimizes the performance of the renewable energy network and the cellular network. This approach is based on convex optimization theory and the Dinkelback algorithm, and it leads to the design of a carbon efficiency optimization algorithm. This algorithm aims to improve the carbon efficiency of cellular networks and reduce their carbon emissions. Simulation results demonstrate that our optimization scheme yields a maximum improvement of 2.56 × 108bps/g in the carbon efficiency of the cellular network as compared to conventional power allocation schemes such as the traditional water filling method and heuristic energy sharing and charge/discharge algorithms.

关键词： cellular networks renewable energy carbon efficiency convex optimization theory dinkelbach

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Effect of Mo and cold forging deformation on strength and ductility of cobalt-based alloy L605

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Journal of Iron and Steel Research(International) 2024年第7期31卷 1811-1823页

作者： zhong-lin Wang Zhi-hua Gong Quan Li han-sheng Bao School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014017Inner MongoliaChina Institute of Special Steels Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

Mo element was added to cobalt-based alloy L605,and cold forging deformation was *** effects of the addition and cold forging deformation on the microstructure and mechanical properties of the alloy were studied by thermodynamic calculation,electron backscatter diffraction,transmission electron microscopy,and X-ray *** stacking fault energy(SFE)of the alloy decreased after the addition,and the formation of stacking faults and intersections were promoted to improve the strength and *** tensile strength of the alloy with Mo increased from 1190 to 1702 MPa after 24%cold deformation,producing significant work *** strengthening mechanism is strain-induced martensitic transformation(SIMT)and deformation *** alloy,combined with Mo and after 24%deformation,had both high strength and ductility in comparison with the original cobalt-based alloy *** is attributed to the lower SFE which caused the increase in stacking fault *** the tensile process,theε-hcp phase was easily generated at the stacking fault to reduce the stress concentration and increase the *** SIMT by adjusting the density of stacking faults can improve the mechanical properties of cobalt-based ***ε-hcp phase,the interaction between deformation twins and dislocations,and the interaction between e-hcp phases during cold forging deformation caused local stress concentration,lowering ductility and toughness.

关键词： Cobalt-based alloy-Stacking fault energy Strain-induced martensitic transformation Deformation twin Cold forging deformation

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CFD-DEM study on the synergistic effect of coke consumption and particle dynamics in the blast furnace raceway

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Particuology 2024年第6期89卷 270-278页

作者： Peng Xu Peng han Zhijun He Xizhong An kang Sun Lihua Gao Key Laboratory of Green Low-Carbon and Intelligent Metallurgy School of Materials and MetallurgyUniversity of Science and Technology LiaoningAnshan 114000China Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education School of MetallurgyNortheastern UniversityShenyang110819China

In this study,the gas-solid flow process in the blast furnace raceway is numerically simulated using coupled computational fluid dynamics and the discrete element method(CFD-DEM).The coke reaction kinetics data are imported into the DEM model to reproduce the consumption process of each coke *** effects of inlet gas velocity and angle on the morphology of the raceway,coke consumption rate,coke bed temperature,and particle size distribution in the blast process are systematically investigated and *** results show that the consumption of coke particles promotes the formation of raceways during the blast *** the same time,a coke mixture layer is produced at the edge of the *** higher the inlet gas velocity,the thicker the coke mixture layer in the middle and upper parts of the raceway region,and the larger the proportion of small particles in the coke mixture *** effect of the inlet gas angle on the raceway region is less than the inlet gas ***,with the increase in the inlet gas angle,the high-temperature region of the coke bed extends downward gradually,which is conducive to activating the hearth.

关键词： Blast furnace Raceway Multiphase flow CFD-DEM Modeling

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Evolution of In783 alloy in microstructure and properties enduring different service times

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Rare Metals 2024年第1期43卷 334-341页

作者： zhong-Shuai han Jin-Feng Du Jun Liang Zheng Zhang School of Material Science and Engineering Beihang UniversityBeijing 100191China Shenhua Guohua(Beijing)Electric Power Research Institute Co. Ltd.Beijing 100025China

Impact, tensile, and fatigue tests were performed in In783 alloy serving 4000, 23,000 and 48,000 h. The microstructure was then analysed by optical microscopy(OM), scanning electron microscopy(SEM), and transmission electron microscopy(TEM) to probe the relationship between microstructure and properties. The results show that a new Ni_(5)Al_(3) phase is found, which grows gradually in β phase with serving time increasing,destroying the martensitic structure of the β phase, and degenerating the toughness of the β phase(approximately13.88% reduction). Therefore, the degradation of the βphase results in a sharp dropping of the resistance to stress accelerated grain boundary oxygen(SAGBO) during serving;thus, the intergranular fracture morphology degree increases with duration of service(almost 40% increase from the fractured surface). In addition, the strength of alloy will be gradually enhanced when the γ'phase becomes relatively bulky with serving time increasing due to considerable distortion of the dislocations as a result of the spacing of individual particles, in which any movement of the dislocation will have to overcome a larger number of obstacles per unit length.

关键词： In783 Microstructure Properties βphase Ni_(5)Al_(3)phase

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Lateral earth pressure of granular backfills on retaining walls with expanded polystyrene geofoam inclusions under limited surcharge loading

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1388-1397页

作者： Kewei Fan Guangqing Yang Weilie Zou zhong han Yang Shen Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China School of Civil Engineering Wuhan UniversityWuhan430072China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China

Existing studies have focused on the behavior of the retaining wall equipped with expanded polystyrene(EPS)geofoam inclusions under semi-infinite surcharge loading rather than limited surcharge *** this paper,the failure mode and the earth pressure acting on the rigid retaining wall with EPS geofoam inclusions and granular backfills(henceforth referred to as EPS-wall),under limited surcharge loading are investigated through two-and three-dimensional model *** testing results show that different from the sliding of almost all the backfill in the EPS-wall under semi-infinite surcharge loading,only an approximately triangular backfill slides in the wall under limited surcharge *** distribution of the lateral earth pressure on the EPS-wall under limited surcharge loading is non-linear,and the distribution changes from the increase of the wall depth to the decrease with the increase of the limited surcharge *** approach based on the force equilibrium of a differential element is developed to predict the lateral earth pressure behind the EPS-wall subjected to limited surcharge loading,and its performance was fully validated by the three-dimensional model tests.

关键词： Retaining wall Expanded polystyrene(EPS)geofoam Limited surcharge loading Lateral earth pressure Model test Prediction

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Coordination of distinctive pesticide adjuvants and atomization nozzles on droplet spectrum evolution for spatial drift reduction

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Chinese Journal of Chemical Engineering 2024年第2期66卷 250-262页

作者： Shidong Xue Jingkun han Xi Xi zhong Lan Rongfu Wen Xuehu Ma State Key Laboratory of Fine Chemicals Liaoning Key Laboratory of Clean Utilization of Chemical ResourcesInstitute of Chemical EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 16024China School of Fashion and Textiles The Hong Kong Polytechnic UniversityHong Kong 999077China China Tianchen Engineering Corporation Tianjin 300400China School of Energy and Power Engineering Dalian University of TechnologyDalian 116024China

Pesticide adjuvants,as crop protection products,have been widely used to reduce drift loss and improve utilization efficiency by regulating droplet ***,the coordinated regulation mechanisms of adjuvants and nozzles on droplet spectrum remain ***,we established the relationship between droplet spectrum evolution and liquid atomization by investigating the typical characteristics of droplet diameter distribution near the *** on this,the regulation mechanisms of distinctive pesticide adjuvants on droplet spectrum were clarified,and the corresponding drift reduction performances were quantitively evaluated by wind tunnel *** shows that the droplet diameter firstly shifts to the smaller due to the liquid sheet breakup and then prefers to increase caused by droplet *** the surface tension of sprayed liquid facilitates the uniform liquid breakup and increasing the viscosity inhibits the liquid deformation,which prolong the atomization process and effectively improve the droplet *** a result,the drift losses of flat-fan and hollow cone nozzles are reduced by about 50%after adding organosilicon and vegetable oil *** contrast,the air induction nozzle shows a superior anti-drift ability,regardless of distinctive *** findings provide insights into rational adjuvant design and nozzle selection in the field application.

关键词： Pesticide drift Spray droplets Particle size distribution Spray atomization Transport processes Adjuvants

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