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Water modeling on fluid flow and mixing phenomena in a BOF steelmaking converter

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Journal of Iron and Steel Research international 2024年第3期31卷 595-607页

作者： Xin-yu Cai Hao-jian Duan Ding-han Li Anjun Xu Li-feng Zhang school of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing 100083China school of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

A 1∶8 physical water model was constructed to investigate the fluid flow and mixing phenomena in the basic oxygen furnace(BOF)*** particle image velocimetry was employed to measure the velocity distribution of the bath and the high-speed camera was applied to capture the cavity shape in the combined blowing BOF *** mixing time for varied operating conditions was measured by the stimulus-response *** cavity depth increased with the decrease in the lance height and the increase in the top gas flow rate while the bottom blowing gas had little influence on the cavity *** minimum cavity depth was obtained under the condition of a 69.8 m^(3)/h top gas flow rate,a 287.5 mm lance height and a 0.93 m^(3)/h bottom blowing gas flow rate,which was 161.2 *** mixing time decreased as the lance height decreased and the top blowing gas flow rate *** mixing time was first decreased and then increased with the increase in the bottom gas flow *** the condition of 69.8 m^(3)/h gas flow rate of top blowing,the 287.5 mm lance height and the 0.93 m^(3)/h gas flow rate of bottom blowing,the mixing time in the converter was 48.65 *** empirical formula between the stirring power and the mixing time in the converter was calculated.

关键词： Water model Fluid flow Particle image velocimetry Mixing time BOF converter

Bichromatically pumped artificial cnoidal wave breathers in optical microresonators

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Photonics Research 2024年第7期12卷 1464-1477页

作者： YIRAN GAO JIAN DAI ZHONGHAN WU ANNI LIU TIAN ZHANG WEI SUN JUNQIU LIU KUN XU State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China school of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China school of Communication Engineering Hangzhou Dianzi UniversityHangzhou 310018China international Quantum Academy Shenzhen 518048China Hefei National Laboratory University of Science and Technology of ChinaHefei 230026China

Breathers are localized structures that undergo a periodic oscillation in their duration and amplitude. Optical microresonators, benefiting from their high-quality factor, provide an ideal test bench for studying breathing phenomena. In a monochromatically pumped microresonator system, intrinsic breathing instabilities are widely observed in the form of temporal dissipative Kerr solitons which only exist in the effectively red-detuned ***, we demonstrate a novel bichromatic pumping scheme to create compulsive breathing microcombs via respectively distributing two pump lasers at the effectively blue-and red-detuned sides of a single *** experimentally discover the artificial cnoidal wave breathers and molecular crystal-like breathers in a photonic chip-based silicon nitride microresonator and theoretically describe their intriguing temporal dynamics based on the bichromatic pumping Lugiato–Lefever equation. In particular, the corresponding breathing microcombs exhibit diverse comb line spacing ranging from 2 to 17 times the free spectral range of the *** discovery not only provides a simple yet robust method to harness microcombs with reconfigurable comb line spacing but also reveals a new class of breathing waves in driven dissipative nonlinear systems.

关键词： pumped resonator pumping

A state-of-the-art review on delayed expansion of cemented paste backfill materials

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Rare Metals 2024年第8期43卷 3475-3500页

作者： Meng-Yuan Li Li-Jie Guo Yue Zhao Lei Zhang Kai Yang Xiao-Peng Peng Andrew Pan BGRIMM Technology Group Beijing 100160China National Centre for international Research On Green Metal Mining Beijing102628China Department of Civil and Mineral Engineering University of TorontoTorontoON M5S 1A4Canada

Utilizing delayed expansion cemented paste backfill materials(DECPB) in mine backfill operations offers an effective solution to the challenge of achieving proper contact between the in-situ cemented backfill mass and the roof in mined-out areas(backfill-roof contact).This article presents recent progress in both theoretical and experimental research concerning *** types and mechanisms of expansive additives,including expansive agents,foaming agents,and expansive mineral materials relevant to DECPB,are explained,along with their impact on the expansive properties and mechanical characteristics of *** composition,material characteristics,preparation methods,and controlled release mechanisms of microcapsules are *** methods for measuring the volume change rate of paste backfill slurries are *** indicates that an appropriate content of expansive additives not only enhances the expansive properties of cemented paste backfill materials but also contributes to improving their mechanical *** foaming agents and bentonite are found to be more suitable for preparing DECPB compared to expansive *** delayed expansion of cemented paste backfill material is influenced by microcapsules,with their wall materials,preparation parameters,and the alkaline slurry environment affecting their controlled release *** and optimizing precise measurement devices and methods forfor the volume change rate of cemented paste backfill materials is essential requirement for studying the performance of *** delayed expansion technology with retarding techniques in cemented paste backfill materials can provide a reliable solution for achieving proper backfill-roof contact in the future.

关键词： Paste backfill Delayed expansion Mining with backfill Expansive additives Tailings

Adsorption and sensing characteristics of insulating gas C4F7N on 3d late transition metal-phthalocyanine:Theoretical and experimental study

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High Voltage 2024年第4期9卷 870-878页

作者： Dachang Chen Ziang Zheng Cong Zhang Yi Luo Song Xiao Qing Miao Ke Liu Beibei Xiao school of Electrical and Electronic Engineering Wuhan Polytechnic UniversityWuhanChina beijing international S&T Cooperation Base for Plasma Science and Energy Conversion Institute of Electrical EngineeringChinese Academy of SciencesBeijingChina school of Electrical Engineering and Automation Wuhan UniversityWuhanChina school of Energy and Power Engineering Jiangsu University of Science and TechnologyZhenjiangChina

Heptafluoroisobutyronitrile(C_(4)F_(7)N)is being considered as a promising alternative to the greenhouse gas SF6 in the electrical ***,its biotoxicity necessitates the development of gas sensing technology to detect leaked C_(4)F_(7)N.A combination of density functional theory and experiments was employed to evaluate the adsorption and sensing performance of different metal-phthalocyanines as potential sensing materials for C_(4)F_(7)N *** study included exploring adsorption configurations with adsorption energies,electron transfer,and adsorption distance,as well as comparisons of electronic properties,electron distribution,and density of states(DOS)among the ***,gas sensing experiments were conducted using different MPcs to detect 25-100 ppm C_(4)F_(7)*** results revealed that Mn-Pc,Fe-Pc,Co-Pc,and Zn-Pc exhibited considerable chemical interactions,while Ni-Pc and Cu-Pc showed weaker adsorption *** findings were further elucidated based on the electron density and DOS of atomic ***,gas sensing experiments indicated that Co-Pc demonstrated a higher response compared to Fe-Pc at the same concentration of C_(4)F_(7)***,the theoretical and experimental insights offer valuable guidance for C_(4)F_(7)N detection and provide a systematic approach to screen and explore organometallic polymer-based gas sensors applicable in various fields.

关键词： adsorption phthalocyanine Adsorption

Reinforcement Learning-Based Energy Management for Hybrid Power Systems:State-of-the-Art Survey,Review,and Perspectives

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 1-25页

作者： Xiaolin Tang Jiaxin Chen Yechen Qin Teng Liu Kai Yang Amir Khajepour Shen Li College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China school of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Department of Mechanical and Mechatronics Engineering University of WaterlooWaterlooON N2L 3G1Canada school of Civil Engineering Tsinghua UniversityBeijing 100084China

The new energy vehicle plays a crucial role in green transportation,and the energy management strategy of hybrid power systems is essential for ensuring energy-efficient *** paper presents a state-of-the-art survey and review of reinforcement learning-based energy management strategies for hybrid power ***,it envisions the outlook for autonomous intelligent hybrid electric vehicles,with reinforcement learning as the foundational *** of all,to provide a macro view of historical development,the brief history of deep learning,reinforcement learning,and deep reinforcement learning is presented in the form of a ***,the comprehensive survey and review are conducted by collecting papers from mainstream academic *** most of the contributions based on three main directions—algorithm innovation,powertrain innovation,and environment innovation—provides an objective review of the research ***,to advance the application of reinforcement learning in autonomous intelligent hybrid electric vehicles,future research plans positioned as“Alpha HEV”are envisioned,integrating Autopilot and energy-saving control.

关键词： New energy vehicle Hybrid power system Reinforcement learning Energy management strategy

Influence of water coupling coefficient on the blasting effect of red sandstone specimens

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international Journal of Coal Science & Technology 2024年第1期11卷 148-166页

作者： Yang Li Renshu Yang Yanbing Wang Dairui Fu school of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing100083China school of Civil and Resource Engineering University of Science and Technology BeijingBeijing100083China

This study investigates the impact of different water coupling coefficients on the blasting effect of red *** analysis is based on the theories of detonation wave and elastic wave,focusing on the variation in wall pressure of the blasting *** DDNP explosive as the explosive load,blasting tests were conducted on red sandstone specimens with four different water coupling coefficients:1.20,1.33,1.50,and *** study examines the morphologies of the rock specimens after blasting under these different water coupling ***,the fractal dimensions of the surface cracks resulting from the blasting were calculated to provide a quantitative evaluation of the extent of rock *** scanning and 3D reconstruction were performed on the post-blasting specimens to visually depict the extent of damage and fractures within the ***,the volume fractal dimension and damage degree of the post-blasting specimens are *** findings are then combined with numerical simulation to facilitate auxiliary *** results demonstrate that an increase in the water coupling coefficient leads to a reduction in the peak pressure on the hole wall and the crushing zone,enabling more of the explosion energy to be utilized for crack propagation following the *** specimens exhibited distinct failure patterns,resulting in corresponding changes in fractal *** simulated pore wall pressure–time curve validated the derived theoretical results,whereas the stress cloud map and explosion energy-time curve demonstrated the buffering effect of the water *** the water coupling coefficient increases,the buffering effect of the water medium becomes increasingly prominent.

关键词： Water coupling coefficient Radial uncoupled charge Numerical simulation Fractal dimension

Complex granular flows of sticky-wet material on flip-flow screens:Calibration of discrete element simulations

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Particuology 2024年第1期84卷 290-308页

作者： Ningning Xu Sen Tang Dongdong Lin Runhui Geng Xinwen Wang Xihui Liang school of Chemical and Environmental Engineering China University of Mining and Technology(Beijing)Beijing100083China Department of Mechanical Engineering University of ManitobaWinnipegManitobaR3T 5V6Canada

Discrete element method(DEM)is an effective approach for studying the screening process of flip-flow ***,there have been few studies focusing on the thick layer of sticky-wet particles on flip-flow *** achieve accurate simulations of the thick layer of sticky-wet particles on a flip-flow screen,firstly,the movement law of particle flow was studied,and a multi-regime combination cali-bration method based on characteristics of particle flow regimes was *** on the Plackett-Burman experiment,the curse of dimensionality caused by multi-state and multi-contact parameters was ***,the lifting cylinder,rotating drum,and trampoline tests were carried out to obtain macroscopic reference values under various granular flow *** calibration results were then determined using the response surface method and climbing ***,the calibration results were tested at both macroscopic and mesoscopic scales and compared with a commonly used calibration *** results demonstrate that the calibration method,which considers the multi-state characteristics,improves simulation accuracy by 2%-10%and reduces the simulation error to less than 10%,thus meeting the requirements for engineering optimization of flip-flow screens.

关键词： DEM Complex granular flow Parameter calibration Flip-flow screen Sticky-wet particles Thick layer

Maximizing Submodular+Supermodular Functions Subject to a Fairness Constraint

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Tsinghua Science and Technology 2024年第1期29卷 46-55页

作者： Zhenning Zhang Kaiqiao Meng Donglei Du Yang Zhou beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing 100124China Faculty of Management University of New BrunswickFredericton E3B 5A3Canada school of Mathematics and Statistics Shandong Normal UniversityJinan 250014China

We investigate the problem of maximizing the sum of submodular and supermodular functions under a fairness *** sum function is non-submodular in *** an offline model,we introduce two approximation algorithms:A greedy algorithm and a threshold greedy *** a streaming model,we propose a one-pass streaming *** also analyze the approximation ratios of these algorithms,which all depend on the total curvature of the supermodular *** total curvature is computable in polynomial time and widely utilized in the literature.

关键词： submodular function supermodular function fairness constraint greedy algorithm threshold greedy algorithm streaming algorithm

A multi-colloidal gold immunochromatography assay for rapid and simultaneous detection of 13 herbicides

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Nano Research 2024年第9期17卷 8368-8376页

作者： Qianqian Lu Xinxin Xu Aihua Qu Liqiang Liu Yuzhe Li Maozhong Sun Chuanlai Xu Hua Kuang international Joint Research Laboratory for Biointerface and Biodetection and School of Food Science and TechnologyJiangnan UniversityWuxi 214122China China National Center for Food Safety Risk Assessment Beijing 100021China

Herbicide residues in agricultural products can have adverse effects on the environment and human health,therefore,there is an urgent need to establish a sensitive,rapid,and wide-ranging detection *** this study,haptens of phenylurea herbicides(PUs)and sulfonylurea herbicides(SUs)were analyzed and designed based on computational simulation techniques,and two high-performance broad-spectrum monoclonal antibodies against PUs and SUs were *** this basis,a multi-colloidal gold immunochromatography assay(multi-CGIA)was developed to simultaneously detect 13 herbicides in *** visual limit of detection(vLOD)for PUs including diuron,chlortoluron,neburon,chlorbromuron,and linuron was 1-2μg/*** vLOD for SUs including metsulfuron methyl,ethametsulfuron-methyl,sulfometuron-methyl,tribenuron methyl,cinosulfuron,triasulfuron,chlorimuron-ethyl,and chlorsulfuron was 2-10μg/*** results of real sample determination indicated that the multi-CGIA is accurate,stable,and reliable,and adaptable to on-site preliminary screening of actual samples.

关键词： phenylurea herbicides sulfonylurea herbicides monoclonal antibody immunochromatographic assay wheat