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Facile synthesis of Fe/Ni bimetallic oxide solid-solution nanoparticles with superior electrocatalytic activity for oxygen evolution reaction

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Nano Research 2015年第12期8卷 3815-3822页

作者： Lingxiao Wang Jing geng Wenhai Wang chao Yuan Long Kuai Baoyou geng College of Chemistry and Materials Science The Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Laboratoryof Molecular-Based Materials Center for Nano Science and Technology Anhui Normal University No. 1 Beijing East Road Wuhu 241000 China

The sluggish oxygen evolution reaction （OER） is an important half-reaction of the electrochemical water-splitting reaction. Amorphous Fe/Ni composite oxides have high activity. In this work, we modified the aerosol spray-assisted approach and obtained amorphous Fe-Ni-Ox solid-solution nanoparticles （Fe-Ni-Ox-NPs） approximately 20 nm in size by choosing iron/nickel acetylacetonates as raw materials instead of inorganic salts. The small-sized Fe-Ni-Ox-NPs were characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） analysis, energy-dispersive X-ray spectroscopy （EDX）, and X-ray photoelectron spectroscopy （XPS）. Furthermore, an investigation of electrochemical OER performance suggests that the small-sized Fe-Ni-Ox-NPs have higher activity than the large-sized Fe-Ni-Ox-MPs. A small overpotential of 0.315 V was demanded to obtain a working current density of 50 mA/cm2, and the Tafel slope was as low as 38 mWdec.

关键词： Fe-Ni-Ox solid solution electrocatalysis oxygen evolution reaction

A Modeling and Probabilistic Reasoning Method of Dynamic Uncertain Causality Graph for Industrial Fault Diagnosis

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International Journal of Automation and computing 2014年第3期11卷 288-298页

作者： Chun-Ling Dong Qin Zhang Shi-chao geng Department of Geographical Information System Shandong Normal University School of Computer Science and Engineering Beihang University Institute of Nuclear and New Energy Technology Tsinghua University

Online automatic fault diagnosis in industrial systems is essential for guaranteeing safe, reliable and efficient ***, difficulties associated with computational overload, ubiquitous uncertainties and insufficient fault samples hamper the engineering application of intelligent fault diagnosis technology. Geared towards the settlement of these problems, this paper introduces the method of dynamic uncertain causality graph, which is a new attempt to model complex behaviors of real-world systems under uncertainties. The visual representation to causality pathways and self-relied "chaining" inference mechanisms are analyzed. In particular, some solutions are investigated for the diagnostic reasoning algorithm to aim at reducing its computational complexity and improving the robustness to potential losses and imprecisions in observations. To evaluate the effectiveness and performance of this method, experiments are conducted using both synthetic calculation cases and generator faults of a nuclear power plant. The results manifest the high diagnostic accuracy and efficiency, suggesting its practical significance in large-scale industrial applications.

关键词： Fault diagnosis causality model probabilistic graphical model uncertain knowledge representation weighted logic inference.

Simulation of the characteristics of low-energy proton induced single event upset

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Science China(Physics,Mechanics & Astronomy) 2014年第10期57卷 1902-1906页

作者： geng chao XI Kai LIU TianQi LIU Jie Institute of Modern Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

Monte Carlo simulation results are reported on the single event upset(SEU) triggered by the direct ionization effect of low-energy proton. The SEU cross-sections on the 45 nm static random access memory(SRAM) were compared with previous research work, which not only validated the simulation approach used herein, but also exposed the existence of saturated cross-section and the multiple bit upsets(MBUs) when the incident energy was less than 1 MeV. Additionally, it was observed that the saturated cross-section and MBUs are involved with energy loss and critical charge. The amount of deposited charge and the distribution with respect to the critical charge as the supplemental evidence are discussed.

关键词： single event upset proton direct ionization Monte Carlo

Accounting for Polychromatic Light in Virtual Shack-Hartmann Wavefront Sensing

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Photonic Sensors 2023年第3期13卷 8-22页

作者： Xian YUE Yaliang YANG Hao DAI Shen CHEN chao geng Yudong ZHANG Key Laboratory of Adaptive Optics Chinese Academy of SciencesChengdu 610209China Institute of Optics and Electronics Chinese Academy of SciencesChengdu 610209China University of Chinese Academy of Sciences Beijing 100049China

Virtual Shack-Hartmann wavefront sensing(vSHWS)has some significant advantages and is promising for aberration measurement in the field of biomedical optical *** illumination sources used in vSHWS are almost broadband,but are treated as monochromatic sources(only using center wavelength)in current data processing,which may cause *** work proposed a data processing method to take into account the multiple wavelengths of the broadband spectrum,named multiple-wavelength centroid-weighting *** feasibility was demonstrated through a series of simulations.A wavefront generated with a set of statistical human ocular aberrations was used as the target wavefront to evaluate the performance of the proposed and current *** results showed that their performance was very close when used for the symmetrical,but the wavefront error of the proposed method was much smaller than that of the current method when used for the asymmetrical spectrum,especially for the broader *** results were also validated by using 20 sets of clinical human ocular aberrations including normal and diseased *** proposed method and the obtained conclusions have important implications for the application of vSHWS.

关键词： Wavefront sensing aberration measurement numerical wavefront processing Shack-Hartmann wavefront sensing broadband spectral source

Molecular recognition of cyclophanes in water

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Chinese Chemical Letters 2024年第5期35卷 32-44页

作者： Fang-Yuan Chen Wen-chao geng Kang Cai Dong-Sheng Guo College of Chemistry State Key Laboratory of Elemento-Organic ChemistryKey Laboratory of Functional Polymer Materials(Ministry of Education)Frontiers Science Center for New Organic MatterCollaborative Innovation Center of Chemical Science and Engineering(Tianjin)Nankai UniversityTianjin 300071China College of Chemistry Nankai UniversityTianjin 300071China

Molecular recognition in water,the biological solvent,always receives significant research focus in supramolecular *** mechanisms of molecular recognition in water is key to comprehending biological processes at the molecular *** the past five decades,supramolecular chemists have developed a vast array of synthetic receptors with highly diverse structures and recognition *** them,cyclophanes represent an important family of macrocyclic receptors that have been extensively *** aromatic moieties in cyclophanes not only facilitate chemical modifications to impart water solubility but also enable forming hydrophobic cavities for guest inclusion in aqueous *** by Koga et al.,who reported the first inclusion complex of cyclophanes in water and solid state,numerous water-soluble cyclophanes,including derivatives of blue box,calixarenes,resorcinarenes,pillararenes,octopusarenes,biphenarenes,coronarenes,and naphthotubes,etc.,have been synthesized and subjected to investigation of the recognition capabilities in aqueous *** review provides an overview of cyclophane receptors designed to bind organic guests in *** categorize them into two classes based on the modifications made to their hydrophobic cavities:those with“exo-functionalized hydrophobic cavities”and those with“endo-functionalized hydrophobic cavities”.We introduce their distinctive features and discuss strategies to enhance recognition affinity and *** review aims to inspire the development of novel synthetic receptors with intriguing properties and foster practical applications of cyclophanes.

关键词： Biomimetic receptor Cyclophane Molecular recognition Hydrophobic effect High-affinity Macrocycles

Effects and mechanisms of fluorite on the co-reduction of blast furnace dust and seaside titanomagnetite

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International Journal of Minerals,Metallurgy and Materials 2017年第11期24卷 1201-1210页

作者： Tian-yang Hu Ti-chang Sun Jue Kou chao geng Yong-qiang Zhao School of Civil and Resources Engineering University of Science and Technology Beijing Beijing 100083 China Key Laboratory of Ministry of Education of China for Efficient Mining and Safety of Metal Mines Beijing 100083 China

The co-reduction roasting and grinding-magnetic separation of seaside titanomagnetite and blast furnace dust was investigated with and without fluorite addition at a reduction roasting temperature of 1250°C for 60 min, a grinding fineness of-43 μm accounting for 69.02 wt% of the total, and a low-intensity magnetic field strength of 151 kA/m. The mineral composition, microstructure, and state of the roasted products were analyzed, and the concentrations of CO and CO_2 were analyzed in the co-reduction roasting. Better results were achieved with a small fluorite dosage(≤4 wt%) in the process of co-reduction. In addition, F^- was found to reduce the melting point and viscosity of the slag phase because of the high content of aluminate and silicate minerals in the blast furnace dust. The low moisture content of the blast furnace dust and calcic minerals inhibited the hydrolysis of CaF_2 and the loss of F^-. Compared with the blast furnace dust from Chengdeng, the blast furnace dusts from Jiugang and Jinxin inhibited the diffusion of F-when used as reducing agents, leading to weaker effects of fluorite.

关键词： seaside titanomagnetite blast furnace dust co-reduction roasting fluorite mechanisms

Recovery of iron and copper from copper tailings by coal-based direct reduction and magnetic separation

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Journal of Iron and Steel Research International 2017年第10期24卷 991-997页

作者： chao geng Hua-jun Wang Wen-tao Hu Li Li Cheng-shuai Shi School of Civil and Resource Engineering University of Science and Technology Beijing Key Laboratory for Solid Waste Management and Environment Safety Ministry of Education of ChinaSchool of EnvironmentTsinghua University

A technique comprising coal-based direct reduction followed by magnetic separation was presented to recover iron and copper from copper slag flotation *** process parameters,such as reductant and additive ratios,reduction temperature,and reduction time,were experimentally determined and found to be as follows：a limestone ratio of 25%,a bitumite ratio of 30%,and reduction roasting at 1473 Kfor 90 *** these conditions,copper-bearing iron powders（CIP）with an iron content of 90.11% and copper content of 0.86%,indicating iron and copper recoveries of87.25% and 83.44%respectively,were effectively *** electron microscopy and energy dispersive spectroscopy of the CIP revealed that some tiny copper particles were embedded in metal iron and some copper formed alloy with iron,which was difficult to achieve the separation of these two ***,the copper went into magnetic products by magnetic *** copper into the steel can produce weathering ***,the CIP can be used as an inexpensive raw material for weathering steel.

关键词： Copper slag Coal-based direct reduction Magnetic separation Iron powder Weathering steel

Emulsion Binders with Multiple Crosslinked Structures for High-Performance Lithium-Sulfur Batteries

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Chinese Journal of Polymer Science 2023年第7期41卷 1027-1036页

作者： Ya-Fang Tan Wen-Qiang Wang Ling Gao Ai-Guo Guan geng-chao Wang Shanghai Key Laboratory of Advanced Polymeric Materials Shanghai Engineering Research Center of Hierarchical NanomaterialsSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China

Lithium-sulfur batteries suffer a lot from the huge volume change and the shuttle effect. However, conventional poly(vinylidene fluoride) binder has intrinsic drawbacks, such as low ion conductivity, weak polysulfide-trapping ability, poor mechanical properties, and requirement of organic solvents. Herein, we designed a functional emulsion binder with multi crosslinked structure. Such a structure was formed by the covalent crosslinking within and between the emulsion particles, which facilitates the adapting of the volume expansion of sulfur cathode, thereby ensuring the integrity of electrodes. Besides, the polar functional groups endow the binder with strong chemisorption of lithium polysulfide and fast lithium-ion migration ability. Thus, the assembled lithium-sulfur battery displayed a high initial discharge capacity of 1246 mAh·g^(−1) at 0.1 C, and a capacity fading rate of 0.04% per cycle after 500 cycles at 0.5 C. Even at a high sulfur mass loading of 4.8 mg·cm^(−2), a high capacity of 956 mAh·g^(−1) was still obtained at 0.2 C.

关键词： Acrylate copolymer Internal and external crosslinking Emulsion binders Lithium-sulfur batteries

Effects of embedding direct reduction followed by magnetic separation on recovering titanium and iron of beach titanomagnetite concentrate

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Journal of Iron and Steel Research International 2017年第2期24卷 156-164页

作者： chao geng Ti-chang Sun You-wen Ma Cheng-yan Xu Hui-fen Yang School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China

Embedding direct reduction followed by magnetic separation was conducted to fully recover iron and titanium separately from beach titanomagnetite （TTM）. The influences of reduction conditions, such as molar ratio of C to Fe, reduction time, and reduction temperature, were studied. The results showed that the TTM concentrate was reduced to iron and iron-titanium oxides, depending on the reduction time, and the reduction sequence at 1 200℃ was suggested as follows ： Fe2.75 Ti0.25O4→Fe2TiO4→FeTiO3→FeTi2O5. The reduction temperature played a considerable role in the reduction of TTM concentrates. Increasing temperature from 1 100 to 1 200℃ was beneficial to recovering titanium and iron, whereas the results deteriorated as temperature increased further. The results of X-ray diffraction and scanning electron microscopy analyses showed that low temperature （≤1100℃） was unfavorable for the gasification of reductant, resulting in insufficient reducing atmosphere in the reduction process. The molten phase was formed at high temperatures of 1250-1 300℃, which accelerated the migration rate of metallic particles and suppressed the diffusion of reduction gas, resulting in poor reduction. The optimum conditions for reducing TTM concentrate are as follows： molar ratio of C to Fe of 1.68, reduction time of 150 min, and reduction temperature of 1 200℃. Under these conditions, direct reduction iron powder, assaying 90.28 mass% TFe and 1.73 mass% TiO2 with iron recovery of 90.85%, and titanium concentrate, assaying 46.24 mass% TiO2 with TiO2 recovery of 91.15%, were obtained.

关键词： Titanomagnetite concentrate Direct reduction Reduction condition Direct reduction iron powder Magnetic separation