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Strip flatness prediction of cold rolling based on ensemble methods

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Journal of Iron and Steel Research International 2024年第1期31卷 237-251页

作者： Wu-quan yang Zhi-ting Zhao liang-yu Zhu Xun-yang Gao li wang School of Mechanical and Power Engineering Shenyang University of Chemical TechnologyShenyang110142LiaoningChina

Aiming at the problem of insufficient prediction accuracy of strip flatness at the outlet of cold tandem rolling,the prediction performance of strip flatness based on different ensemble methods was studied and a high-precision prediction ensemble model of strip flatness at the outlet was ***,based on linear regression(LR),K nearest neighbors(KNN),support vector regression,regression trees(RT),and backpropagation neural network(BPN),bagging,boosting,and stacking ensemble methods were used for ensemble ***,three existing ensemble models,i.e.,random forest,extreme random tree(ET)and extreme gradient boosting,were used to conduct experiments and compare the *** research shows that bagging,boosting,and stacking three ensemble methods have the most significant improvement in the prediction accuracy of the regression trees model,which is increased by 5.28%,6.51%,and 5.32%,*** the same time,the stacking ensemble method improves both the simple model and the complex model,and the improvement effect on the simple base model is the greatest,which is 4.69%higher than that of the base model *** all of the ensemble models,the stacking ensemble model of level-1(ET,AdaBoost-RT,LR,BPN)paired with level-2(LR)was discovered to be the best model(EALB-LR)and can be further studied for industrial applications.

关键词： Tandem cold rolling Flatness prediction Machine learning Ensemble method

Effects of Boron Addition on the Microstructure and Mechanical Properties ofγ′‑Strengthened Directionally Solidified CoNi‑Base Superalloy

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1438-1452页

作者： Shasha Qu Yingju li Bingyu Lu Cuiping wang Yuansheng yang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China Guangdong Institute of Special Equipment Inspection and Research Foshan 528251China College of Materials and Fujian Provincial Key Laboratory of Materials Genome Xiamen UniversityXiamen 361005China

The effects of B addition on microstructure and mechanical properties of aγ′-strengthened CoNi-base superalloy are *** addition of B leads to a substantial increase in the volume fraction of both the eutectic structure and *** CoNi-base alloy shows a high solubility limit for the element *** become noticeable in the area surrounding the eutectic structure after the B level exceeds 0.46 at.%.It is found that the compression property and stress rupture life of the 4W2Ta alloys exhibit an initial rise followed by a subsequent drop as the B content gradually increases from 0.08 to 0.78 at.%.The 4W2Ta0.46B alloy demonstrates the most excellent high-temperature strength and stress rupture life,revealing that a moderate amount of B in the alloy noticeably enhances its mechanical properties by enhancing the grain boundary cohesion.

关键词： CoNi-base superalloy Borides Grain boundary Microstructure Mechanical properties

A three-dimensional co-continuous network structure polymer electrolyte with efficient ion transport channels enabling ultralong-life all solid-state lithium metal batteries

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Journal of Energy Chemistry 2024年第7期94卷 635-645页

作者： Meng wang Hu Zhang Yewen li Ruiping liu Huai yang School of Chemical&Environmental Engineering China University of Mining and Technology(Beijing)Beijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering&School of Materials Science and Engineering Peking UniversityBeijing 100871China

Solid polymer electrolytes(SPEs)have emerged as one of the most promising candidates for the construction of solid-state lithium batteries due to their excellent flexibility,scalability,and interface compatibility with ***,a novel all-solid polymer electrolyte(PPLCE)was fabricated by the copolymer network of liquid crystalline monomers and poly(ethylene glycol)dimethacrylate(PEGDMA)acts as a structural frame,combined with poly(ethylene glycol)diglycidyl ether short chain interspersed serving as mobile ion transport *** preparaed PPLCEs exhibit excellent mechanical property and out-standing electrochemical performances,which is attributed to their unique three-dimensional cocontinuous structure,characterized by a cross-linked semi-interpenetrating network and an ionic liquid phase,resulting in a distinctive nanostructure with short-range order and long-range ***,the addition of PEGDMA is proved to be critical to the comprehensive performance of the PPLCEs,which effectively modulates the microscopic morphology of polymer networks and improves the mechanical properties as well as cycling stability of the solid *** used in a lithiumion symmetrical battery configuration,the 6 wt%-PPLCE exhibites super stability,sustaining operation for over 2000 h at 30 C,with minimal and consistent overpotential of 50 *** resulting li|PPLCE|LFP solid-state battery demonstrates high discharge specific capacities of 160.9 and 120.1 mA h g^(-1)at current densities of 0.2 and 1 C,*** after more than 300 cycles at a current density of 0.2 C,it retaines an impressive 73.5%***,it displayes stable cycling for over 180 cycles at a high current density of *** super cycle stability may promote the application for ultralong-life all solid-state lithium metal batteries.

关键词： Solid-state electrolyte lithium-metal batteries liquid crystalline polymer Copolymer 3D co-continuous structure Long cycle stability

Triboelectric nanogenerator hybrid array driven by multiform natural energies and its applications in self-powered cathodic protection

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Science China(Technological Sciences) 2024年第3期67卷 878-890页

作者： SUN Weixiang yang Di LUO Ning li Hao wang DaoAi School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratoryof Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Qingdao Center of Resource Chemistry and New Materials Qingdao 266100China

In view of the increasing energy shortage and environmental pollution, the collection of friction charges to achieve the conversion of various natural energies and provide in-situ cathodic protection for metals is a significant challenge. Here, we designed a dual device-structure TENG composite array with the triboelectric layer of linear siloxane-modified polyurethane(PU) coating. This array could achieve a comprehensive collection for multiple forms of nature energy and cathodic protection of metals in multi-weather conditions. For one thing, the wave-mode TENG based on tanker structure could collect wave energy and showed the output performance with a short-circuit current of 15.5 μA. For another thing, the droplet-mode TENG based on arc-shaped surface structure could collect raindrop kinetic energy and showed the output performance with a short-circuit current of 16.3 μA. Notably, the parallel array of wave-mode TENG(W-TENG) and droplet-mode TENG(D-TENG) could simultaneously collect wave energy and raindrop kinetic energy, which showed a short-circuit current of 30.7 μA. Besides, a selfpowered a cathodic protection system powered by the dual structure TENG array is assembled and the open-circuit potential drop of the carbon steel connected with the TENG array is about 450 mV. Compared with cathodic protection system powered by single structure TENG, the composite array could provide more effective corrosion resistance for marine equipment in rainy weather. Due to the characteristic for comprehensive collection of nature energy, the anti-corrosion system supplied by TENG parallel array possesses great application potential in the all-weather corrosion protection of metal machinery under complex marine conditions.

关键词： triboelectric nanogenerator hybrid structure array siloxane-modified polyurethane cathodic protection

Data delivery delay and cross-layer packet size analysis for reliable transmission of licklider transmission protocol in space networks

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Science China(Information Sciences) 2024年第9期67卷 229-244页

作者： Guannan yang Ruhai wang Kanglian ZHAO Wenfeng li Dong YAN School of Information Engineering Nanjing University of Finance and Economics Drayer Department of Electrical and Computer Engineering Lamar University School of Electronic Science and Engineering Nanjing University Beijing Aircraft Overall Design Department

Delay/disruption tolerant networking(DTN) is proposed as a networking architecture to overcome challenging space communication characteristics for reliable data transmission service in presence of long propagation delays and/or lengthy link disruptions. Bundle protocol(BP) and licklider Transmission Protocol(LTP) are the main key technologies for DTN. LTP red transmission offers a reliable transmission mechanism for space networks. One of the key metrics used to measure the performance of LTP in space applications is the end-to-end data delivery delay, which is influenced by factors such as the quality of spatial channels and the size of cross-layer packets. In this paper, an end-to-end reliable data delivery delay model of LTP red transmission is proposed using a roulette wheel algorithm, and the roulette wheel algorithm is more in line with the typical random characteristics in space networks. The proposed models are validated through real data transmission experiments on a semi-physical testing platform. Furthermore, the impact of cross-layer packet size on the performance of LTP reliable transmission is analyzed, with a focus on bundle size, block size, and segment size. The analysis and study results presented in this paper offer valuable contributions towards enhancing the reliability of LTP transmission in space communication scenarios.

关键词： licklider transmission protocol DTN bundle protocol cross-layer packets size space communication

Deformation characteristics and damage ontologies of soft and hard composite rock masses under impact loading

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Journal of Mountain Science 2024年第5期21卷 1715-1727页

作者： li Jinhua ZHANG Tianyu WU Baolin SU Peili yang yang wang Pan Architectural and Civil Engineering College Xi’an University of Science and TechnologyXi’an 710054China

As one of the most common occurring geological landforms in deep rock formations, the dynamic mechanical properties of layered composite rock bodies under impact loading have been widely studied by scholars. To study the dynamic properties of soft and hard composite rocks with different thickness ratios, this paper utilizes cement, quartz sand and gypsum powder to construct soft and hard composite rock specimens and utilizes a combination of indoor tests, numerical calculations, and theoretical analyses to investigate the mechanical properties of soft and hard composite rock bodies. The test results reveal that:(1) When the proportion of hard rock increases from 20% to 50%, the strength of the combined rock body increases by 69.14 MPa and 87 MPa when the hard rock face and soft rock face are loaded, respectively;however, when the proportion of hard rock is the same, the compressive strength of the hard rock face impact is 9%-17% greater than that of the soft rock face impact;(2) When a specimen of soft and hard combined rock body is subjected to impact loading, the damage mode involves mixed tension and shear damage, and the cracks generally first appear at the ends of the specimen, then develop on the laminar surface from the impact surface, and finally end in the overall damage of the soft rock part. The development rate and the total number of cracks in the same specimen when the hard rock face is impacted are significantly greater than those when the soft rock face is impacted;(3) By introducing Weibull’s statistical strength theory to establish the damage variables of soft-hard combined rock bodies, combined with the DP strength criterion, the damage model and the Kelvin body are concatenated to obtain a statistical damage constitutive model, which can better fit the full stress-strain curve of soft-hard combined rock body specimens under a single impact load.

关键词： Soft and hard composite rock mass Dynamic properties Split Hopkinson pressure bar(SHPB) Numerical simulation Intrinsic damage model

Na^+ and Water Uptake in Relation to the Radial Reflection Coefficient of Root in Arrowleaf Saltbush Under Salt Stress

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Journal of Integrative Plant Biology 2007年第9期49卷 1334-1340页

作者： Xin-Fu Bai Jian-Jun Zhu Ping Zhang Yan-Hua wang li-Qun yang Lei Zhang College of life Sciences Ludong University Yantai 264025 China

The response of halophyte arrowleaf saltbush （Atriplex triangularis Willd） plants to a gradient of salt stress were investigated with hydroponically cultured seedlings. Under salt stress, both the Na^＋ uptake into root xylem and negative pressures in xylem vessels increased with the elevation of salinity （up to 500 mol/m^3） in the root environment. However, the increment in negative pressures in root xylem far from matches the decrease in the osmotic potential of the root bathing solutions, even when the osmotic potential of xylem sap is taken into consideration. The total water potential of xylem sap in arrowleaf saltbush roots was close to the osmotic potential of root bathing solutions when the salt stress was low, but a progressively increased gap between the water potential of xylem sap and the osmotic potential of root bathing solutions was observed when the salinity in the root environment was enhanced. The maximum gap was 1.4 MPa at a salinity level of 500 mol/m^3 without apparent dehydration of the tested plants. This discrepancy could not be explained with the current theories in plant physiology. The radial reflection coefficient of root in arrowleaf saltbush decreased with the enhanced salt stress was and accompanied by an increase in the Na^＋ uptake into xylem sap. However, the relative Na^＋ in xylem exudates based on the corresponding NaCl concentration in the root bathing solutions showed a tendency of decrease. The results showed that the reduction in the radial reflection coefficient of roots in the arrowleaf saltbush did not lead to a mass influx of NaCl into xylem when the radial reflection coefficient of the root was considerably small; and that arrowleaf saltbush could use small xylem pressures to counterbalance the salt stresses, either with the uptake of large amounts of salt, or with the development of xylem pressures dangerously negative. This strategy could be one of the mechanisms behind the high resistance of arrowleaf saltbush plants to

关键词： anti-osmosis arrowleaf saltbush (Atriplex triangularis Willd) radial reflection coefficient of root salt stress xylem pressure

Advancements in synthetic and electrocatalytic exploitation of guest-host intercalated 2D materials

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Progress in Natural Science:Materials International 2024年第3期34卷 454-469页

作者： Qian yang Kun wang Meiling Zhang Feihong Du Jiayang li Chen Zheng Jinyang li School of Chemistry Southwest Jiaotong University Yibin Institute of Southwest Jiaotong University

The emergence and development of layered materials have shown great promise for many applications, especially in recent years, the effective modulation of the physicochemical properties of layered materials by intercalation chemistry has led to great potential in material design. In this paper, we review the reaction mechanisms of different guest species(metal atoms/ions, organic molecules/ions, inorganic molecules and inorganic ions)intercalated into the host layered materials as well as the recent progress. It is also reviewed that layered intercalated materials with controllable structure and tunable physicochemical properties can be prepared through the occurrence of interactions between different subjects and guests. The specific applications of intercalation chemistry in the field of electrocatalysis, such as the hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction and other electrocatalytic reactions, are then discussed, with emphasis on the mechanism of the improved catalytic activity and stability of the layered materials after guest intercalation.

关键词： Electrocatalysis Guest species Intercalation chemistry Layered materials

Controlled Twill Surface Structure Endowing Nanofiber Composite Membrane Excellent Electromagnetic Interference Shielding

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Nano-Micro Letters 2024年第11期16卷 255-273页

作者： Dechang Tao Xin Wen Chenguang yang Kun Yan Zhiyao li Wenwen wang Dong wang Key Laboratory of Textile Fiber and Products(Wuhan Textile University) Ministry of EducationWuhan Textile UniversityWuhan 430200People’s Republic of China College of Chemistry Chemical Engineering and BiotechnologyDonghua UniversityShanghai 201620People’s Republic of China

Inspired by the Chinese Knotting weave structure,an electromagnetic interference(EMI)nanofiber composite membrane with a twill surface was ***(vinyl alcohol-co-ethylene)(Pva-co-PE)nanofibers and twill nylon fabric were used as the matrix and filter templates,respectively.A Pva-co-PEMXene/silver nanowire(Pva-co-PE-MXene/AgNW,PM_(x)Ag)membrane was successfully prepared using a template *** the MXene/AgNW content was only 7.4 wt%(PM_(7.4)Ag),the EMI shielding efficiency(SE)of the composite membrane with the oblique twill structure on the surface was 103.9 dB and the surface twill structure improved the EMI by 38.5%.This result was attributed to the pre-interference of the oblique twill structure in the direction of the incident EM wave,which enhanced the probability of the electromagnetic waves randomly colliding with the MXene ***,the internal reflection and ohmic and resonance losses were *** PM_(7.4)Ag membrane with the twill structure exhibited both an outstanding tensile strength of 22.8 MPa and EMI SE/t of 3925.2 dB cm^(-1).Moreover,the PM_(x)Ag nanocomposite membranes demonstrated an excellent thermal management performance,hydrophobicity,non-flammability,and performance stability,which was demonstrated by an EMI SE of 97.3%in a high-temperature environment of 140℃.The successful preparation of surface-twill composite membranes makes it difficult to achieve both a low filler content and a high EMI SE in electromagnetic shielding *** strategy provides a new approach for preparing thin membranes with excellent EMI properties.

关键词： Twill surface structure MXene/AgNW Nanofiber membrane Electromagnetic interference Flexibility and mechanical properties