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Heat distribution model under hydrogen-rich low-carbon conditions in blast furnace

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Journal of Iron and Steel Research International 2024年第3期31卷 584-594页

作者： Gang wang Jun Xu Kun He Zhong-ping Zou Hao Bai School of Metallurgy and Ecological Engineering University of Science and Technology BeijingBeijing 100083China cISDI Low-carbon Blast Furnace Research Office MCC Low-Carbon Technology Research InstituteChongqing 401122China

Low carbon development of blast furnaces is one of the key technological directions in the current development of *** to the differences in the physical and chemical properties of hydrogen and carbon,hydrogen-rich media entering a blast furnace will change the heat distribution,thus affecting the stability of ***,a heat distribution model was proposed to study the temperature distribution in a blast furnace,simultaneously considering gas-solid heat exchange,slag and iron melting,and chemical *** model was used to analyze the temperature distribution of a 2300 m^(3) blast furnace and was verified via comparison with actual production ***,the effects of the injection rate of hydrogen-rich media,H2 concentration,and oxygen enrichment rate of the blast on the temperature distribution were *** indicated that the increase in the injection rate of the hydrogen-rich media decreased the amount of direct reduction and led to an increase in the furnace ***,an increase in the oxygen enrichment rate led to a decrease in the furnace temperature,but could reduce the solid fuel ratio,while the change in H2 concentration had less effect on the temperature *** combination of hydrogen-rich media injection and the increase in the oxygen enrichment rate would help to adjust the temperature distribution to the same level as the conventional blast furnace conditions.

关键词： Heat distribution Blast furnace Low-carbon condition Hydrogen enrichment calculation model

Hydrodynamic Performance of An Integrated System of Breakwater and A Multi-chamber Owc wave Energy converter

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china Ocean Engineering 2024年第4期38卷 543-556页

作者： NING De-zhi ZHANG Xiang-yu wang Rong-quan ZHAO Ming State Key Laboratory of coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China Dalian Key Laboratory of Offshore Renewable Energy Dalian University of TechnologyDalian 116024China School of computing Engineering and MathematicsUniversity of Western SydneyPenrith NSW 2751Australia

A multi-chamber oscillating water column wave energy converter(Owc-wEc)integrated to a breakwater is *** hydrodynamic characteristics of the device are analyzed using an analytical model based on the linear potential flow theory.A pneumatic model is employed to investigate the relationship between the air mass flux in the chamber and the turbine *** effects of chamber width,wall draft and wall thickness on the hydrodynamic performance of a dual-chamber Owc-wEc are *** results demonstrate that the device,with a smaller front wall draft and a wider rear chamber exhibits a broader effective frequency *** device with a chamber-width-ratio of 1:3 performs better in terms of power ***,results from the analysis of a triplechamber Owc-wEc demonstrate that reducing the front chamber width and increasing the rearward chamber width can improve the total performance of the *** the number of chambers from 1 to 2 or 3 can widen the effective frequency bandwidth.

关键词： oscillating water column power extraction efficiency potential flow theory wave energy converter multi-chamber

Magnetically controllable multimode interference in topological photonic crystals

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Light(Science & Applications) 2024年第5期13卷 998-1005页

作者： weiyuan Tang Mudi wang Shaojie Ma che Ting chan Shuang Zhang New cornerstone Science Laboratory Department of PhysicsThe University of Hong KongHong KongChina. Department of Physics The Hong Kong University of Science and TechnologyHong KongChina. Department of Optical Science and Engineering Fudan UniversityShanghai 200433China

Topological photonic insulators show promise for applications in compact integrated photonic circuits due to their ability to transport light robustly through sharp *** number of topological edge states relies on the difference between the bulk chern numbers across the boundary,as dictated by the bulk edge *** interference among multiple topological edge modes in topological photonics systems may allow for controllable functionalities that are particularly desirable for constructing reconfigurable photonic *** this work,we demonstrate magnetically controllable multimode interference based on gyromagnetic topological photonic insulators that support two unidirectional edge modes with different *** successfully achieve controllable power splitting in experiments by engineering multimode interference with the magnetic field intensity or the frequency of *** work demonstrates that manipulating the interference among multiple chiral edge modes can facilitate the advancement of highly efficient and adaptable microwave devices.

关键词： multimode controllable microwave

cr-catalyzed allylic c(sp^(3))–H addition to aldehydes enabled by photoinduced ligand-to-metal charge transfer

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Science china chemistry 2024年第5期67卷 1589-1595页

作者： Xianrong Zeng Feng-Hua Zhang Runchen Lai Xiaoyu Lin Zhaobin wang Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province Department of ChemistrySchool of Science and Research Center for Industries of the FutureWestlake UniversityHangzhou 310030China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province Instrumentation and Service Center for Molecular SciencesWestlake UniversityHangzhou 310024China

Photoinduced ligand-to-metal charge transfer(LMcT) has emerged as an effective strategy for synthesizing organic molecules in a sustainable manner. However, the majority of existing reports on selective c(sp^(3))–H bond functionalization via photoinduced LMcT focus on the use of late transition metals or rare-earth metals for radical additions or cross-couplings. In contrast, the utilization of photoinduced LMcT with 3d early transition metals poses a significant challenge. Herein, we describe an unprecedented approach to allylic c(sp^(3))–H addition to aldehydes, employing chromium(cr) complexes as catalysts through visible-light-induced LMcT. By investigating the reaction pathway through various mechanistic studies, including radical trapping, kinetic isotope effect(KIE) analysis, and transient absorption spectroscopy, valuable insights have been gained. The proposed mechanism suggests the intermediacy of bromine radicals through homolysis of the cr–Br bond. Notably, this protocol expands our understanding of the photochemical properties of earth-abundant cr complexes.

关键词： cr catalysis photoinduced ligand-to-metal charge transfer hydrogen-atom transfer carbonyl addition

Ferrite features in simulated transition zone of EH36 shipbuilding steel submerged arc welded by caF_(2)-SiO_(2)-MnO fluxes

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Journal of Iron and Steel Research International 2024年第4期31卷 790-796页

作者： Ming Zhong Dong Hu Da-ming Guo Somnath Basu cong wang Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Department of Metallurgical Engineering and Materials Science Indian Institute of Technology BombayMumbai 400076MaharashtraIndia

Ferrite features in the simulated transition zone welded with caF_(2)-SiO_(2)-MnO fluxes containing various MnO contents have been *** laser scanning microscopy has been applied to simulate the thermal cycling of the transition zone and the phase transformations during cooling have been in-situ *** has been found that the appearance temperature for ferrite side plate decreases with increasing Mn content in the weld metals caused by MnO content ***,growth rates for both ferrite side plate and acicular ferrite are significantly enhanced with a higher Mn content of weld ***,from the statistical fractions of salient microstructures,for all samples,the acicular ferrite,grain boundary ferrite,and polygonal ferrite take over more than 90%.It has also been demonstrated that with the increase in Mn content,the ferrite side plate fraction increases slightly from 5%to 10%and the acicular ferrite fraction shows a tendency of first increasing and then decreasing,which experiences the maximum with the flux containing 30 wt.%*** phenomenon is believed to be controlled by the O and Mn contents in weld metals synergistically.

关键词： Submerged arc welding Transition zone Phase transformation Microstructure

Efficient construction of calcium fluoride nanoaggregates for enhanced water vapor adsorption

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Particuology 2024年第6期89卷 191-197页

作者： Dan-Lei Yang Jing cao Rong-Kun Liu Jie-Xin wang School of Life Sciences and chemical Engineering Jiangsu Second Normal UniversityNanjing210013China State Key Laboratory of Organic-Inorganic composites Beijing University of Chemical TechnologyBeijing 100029China Research center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing100029China Petrochemical Research Institute PetroChinaBeijing102206China

calcium fluoride(caF_(2))is an ideal adsorbent for the dehydration of gaseous hydrogen fluoride(HF)containing water *** this work,a novel caF_(2)absorbent,spherical caF_(2)nanoaggregates(NAs)with a closely packed structure,was proposed and efficiently fabricated by spray drying *** the building blocks of caF_(2)NAs,the caF_(2)nanoparticles(NPs)were prepared by the addition of excess calcium ions(ca^(2+))or fluorine ions(F−)in the *** results indicated that the caF_(2)NPs synthesized by excess ca^(2+)and the corresponding NAs exhibited much better water vapor adsorption properties than their counterparts by excess F−,owing to higher zeta *** importantly,whether excess ca^(2+)or F^(−),caF_(2)NAs had further enhanced water vapor adsorption capacity compared to primary caF_(2)NPs,possibly owing to their unique nano-micro secondary structures and higher surface *** work has great potential in the development of high-performance absorbents for separating moisture from corrosive gas HF.

关键词： caF_(2)nanoaggregates water vapor adsorption Spray drying

comparison of Rotating Stall warning by Different Methods for Variable Speed configurations in a contra-Rotating compressor

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Journal of Thermal Science 2024年第4期33卷 1379-1393页

作者： XUE Fei wang Yan'gang LIU Qian wU Tong LIU Hanru School of Power and Energy Northwestern Polytechnical UniversityXi’an710072China

Stall in compressors can cause performance degradation and even lead to *** unacceptable consequences can be avoided by timely monitoring stall inception and taking effective *** paper focused on the rotating stall warning in a low-speed axial contra-rotating ***,the stall disturbance characteristics under different speed configurations were *** results showed that as the speed ratio(RR)increased,the stall disturbance propagation speed based on the rear rotor speed gradually ***,the standard deviation(SD)method,the cross-correlation(cc)method,and the discrete wavelet transform(DwT)method were employed to obtain the stall initiation moments of three different speed *** was found that the SD and cc methods did not achieve significant stall warning results in all three speed ***,the stall initiation moment obtained by the DwT method at RR=1.125 was one period after the stall had fully developed,which was ***,a stall warning method was developed in the present work based on the long short-term memory(LSTM)regression *** applying the LSTM model,the predicted stall initiation moments of three speed configurations were at the 557th,518th,and 333rd revolution,which were44,2,and 74 revolutions ahead of stall onset moments,***,in scenarios where a minor disturbance preceded the stall,the stall warning effect of the LSTM was greatly improved in comparison with the aforementioned three *** contrast,when the pressure fluctuation before the stall was relatively small,the differences between the stall initiation moments predicted by these four methods were not significant.

关键词： contra-rotating compressor stall disturbance stall initiation moment long short-term memory(LSTM) stall warning

Fine Sand and clay Sediment Acoustic Properties of the Novel Sediment Sample from the Arabian Sea:Experimental Investigations and Biot−Stoll Model Validation

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china Ocean Engineering 2024年第1期38卷 169-180页

作者： Shahabuddin SHAIKH HUANG Yi-wang ZHANG Ze-chuan Habib Hussain ZUBERI National Key Laboratory of Underwater Acoustic Technology and college of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China

The present study explores the physical and acoustic characteristics of fine sand and clay in novel seabed marine sediments from of Pakistan coastline of the Arabian *** measured physical parameters included mean grain size,mass density,bulk density,salinity,porosity,permeability,pore size and mineralogical *** properties,including sound speed and attenuation,in the high frequency range of 90-170 kHz were analyzed.A controlled laboratory setup with the acoustic transmission method and Fourier transform techniques was utilized to examine the sound propagation and absorption of novel seabed *** standard deviation of mean sound speed in fresh water was 0.75 m/s,and attenuation was observed in the range of 0.43 to 0.61 dB/*** mean sound velocity in sand and clay varied from 1706 to 1709 m/s and 1602 to 1608 m/s,*** average attenuation was observed at 80 to 93 dB/m in sandy sediments and from 31.8 to 38.6 dB/m in clayey *** velocity variation within sandy sediment is low,consistent with expected results,and smaller than the predicted ***,clay sediment exhibited a positive linear correlation and low sound speed *** increased linearly with frequency for both ***,the laboratory results were validated by using the Biot−Stoll *** dispersion of sound speed in sandy and clayey sediments was consistent with the predictions of the Biot−Stoll *** attenuation aligned more with Biot−Stoll model predictions due to improved permeability,tortuosity and pore size parameter fitting.

关键词： physical and acoustic characteristics marine sediments sound speed attenuation Biot−Stoll model

ZrNiSn-based compounds with high thermoelectric performance and ultralow lattice thermal conductivity via introduction of multiscale scattering centers

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Journal of Materiomics 2024年第1期10卷 200-209页

作者： Ruonan Min Yanxia wang Xue Jiang Rongchun chen Mingyang Li Huijun Kang Xiong Yang Zongning chen Enyu Guo Tongmin wang Key Laboratory of Solidification control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Ningbo Institute of Dalian University of Technology Ningbo315000China Key Laboratory of Materials Modification by Laser Ion and Electron Beams(Dalian University of Technology)Ministry of EducationDalian116024China

The high lattice thermal conductivity of half-Heuslers(HHs)restricts the further enhancement of their thermoelectric figure-of-merit(ZT).In this study,multiscale scattering centers,such as point defects,dislocations,and nanoprecipitates,are synchronously introduced in a n-type ZrNiSn-based HH matrix through Nb doping and Hf *** lattice thermal conductivity is substantially decreased from 4.55(for the pristine ZrNiSn)to 1.8 w·m^(−1)·K^(−1) at 1123 K via phonon scattering over a broad wavelength range through the adjustment of multiscale *** value is close to the theoretically estimated lowest thermal *** power factor(PF)is enhanced from 3.25(for the pristine ZrNiSn)to 5.01 mw·m^(−1)·K^(−2) for Zr_(0.66)Hf_(0.30)Nb_(0.04)NiSn at 1123 K owing to the donor doping and band regulation via Nb doping and Hf *** can be ascribed to the synergistic interaction between the lowering of the lattice thermal conductivity and retention of the high ***,a ZT value of as high as 1.06 is achieved for Zr_(0.66)Hf_(0.30)Nb_(0.04)NiSn at 1123 *** work demonstrates that these actions are effective in jointly manipulating the transport of electrons and phonons,thereby improving the thermoelectric performance through defect engineering.

关键词： Half-Heusler compounds Dislocation Lattice thermal conductivity Nano precipitated phase Mechanical properties