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Microstructure and texture evolution of Cu-Cr-Co-Ti alloys during the two-stage cryorolling

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Rare Metals 2024年第9期43卷 4535-4547页

作者： Jia-Jun zhang long-Jian Li Zhi-Feng Liu Zong-Ning Chen En-Yu guo Hui-Jun Kang Ren-Geng Li Tong-Min Wang Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China Center of Hyper-Gravity Experimental and Interdisciplinary Research Zhejiang UniversityHangzhou 310058China Ningbo Institute of Dalian University of Technology Ningbo 315000China Key Laboratory for Light-Weight Materials Nanjing Tech UniversityNanjing 210009China

This study entailed an investigation of the mechanical properties,microstructural and texture orientation evolutions of Cu-Cr-Co-Ti alloys prepared via twostage cryorolling and intermediate aging *** this end,X-ray diffraction and electron backscatter diffraction were *** results indicate that the two-stage cryorolling and intermediate aging treatments led to the development of profuse twin bundles and significantly enhanced the mechanical *** initial cryorolling led to coplanar slip and developed a strong Y({111})orientation,accelerating the formation of Goss({011})orientation and a Brass-type *** intermediate aging treatment relieved the restriction on dislocation slip and reoriented the grains toward the Copper({112})and Z({111})*** Z orientation,with a relatively high volume fraction,dominated the *** cryorolling intensified twinning and shear banding,transforming the Copper-type shear bands into Brass-type shear bands with rhomboidal prism *** areas inside the Brasstype shear bands exhibited a Y orientation,and the areas outside the shear bands exhibited a stable Brass-type *** evident decrease in the weighted Schmid factors demonstrated that the two-stage cryorolling and intermediate aging treatment can modify the texture evolution and aid the design of high-performance Cu alloys.

关键词： Copper alloys Two-stage cryorolling Macrotexture evolution Electron backscatter diffraction Schmid factor

Improving benzene catalytic oxidation on Ag/Co_(3)O_(4) by regulating the chemical states of Co and Ag

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Journal of Environmental Sciences 2024年第9期143卷 201-212页

作者： Hao guo Tao guo Mengqi Zhao Yaxin zhang Wenfeng Shangguan Yinnian Liao State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources Xinjiang UniversityXinjiang 830017China Xinjiang Key Laboratory of Coal Clean Conversion&Chemical Engineering Process Xinjiang UniversityXinjiang 830017China School of Chemical Engineering and Technology Xinjiang UniversityXinjiang 830017China Research Center for Combustion and Environmental Technology Shanghai Jiao Tong UniversityShanghai 200240China School of Applied Chemistry and Materials Zhuhai College of Science and TechnologyGuangdong 519041China

Silver(9 wt.%)was loaded on Co_(3)O_(4)-nanofiber using reduction and impregnation methods,*** to the stronger electronegativity of silver,the ratios of surface Co^(3+)/Co^(2+) on Ag/Co_(3)O_(4) were higher than on Co_(3)O_(4),which further led to more adsorbed oxygen species as a result of the charge ***,the introducing of silver also obviously improved the reducibility of Co_(3)O_(4).Hence the Ag/Co_(3)O_(4) showed better catalytic performance than Co_(3)O_(4) in benzene *** with the Ag/Co_(3)O_(4) synthesized via impregnation method,the one prepared using reduction method(named as Ag Co-R)exhibited higher contents of surface Co^(3+) and adsorbed oxygen species,stronger reducibility,as well as more active surface lattice oxygen ***,Ag Co-R showed lowest T_(90) value of 183℃,admirable catalytic stability,largest normalized reaction rate of1.36×10^(-4)mol/(h·m^(2))(150℃),and lowest apparent activation energy(E_(a))of 63.2 kJ/*** analyzing of in-situ DRIFTS indicated benzene molecules were successively oxidized to phenol,o-benzoquinone,small molecular intermediates,and finally to CO_(2) and water on the surface of Ag *** last,potential reaction pathways including five detailed steps were proposed.

关键词： Reduction method Co_(3)O_(4)-supported Ag catalyst,VOCs Benzene oxidation Reaction mechanism

Glacial-interglacial cycles recorded in clay minerals from the eastern Tibetan Plateau over the last 800 ka and their indications

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Science China Earth Sciences 2024年第7期67卷 2162-2177页

作者： Xiaoyan zhang Chunxia zhang Yan ZHAO Bin HU Zhengtang guo Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Clay mineral proxies have been widely used to reconstruct changes in provenance and the ***,high-altitude clay mineral indications and long-term and orbital variations have not been fully ***,we present an800-ka clay-mineral record from a lacustrine sediment core(ZB13-C2)from the Zoige Basin on the eastern Tibetan Plateau(TP).X-ray diffraction and scanning electron microscopy were used to identify the clay mineral assemblages and their micromorphological characteristics of core *** results revealed that the clay minerals in core ZB13-C2 are mainly illite,with small amounts of chlorite,kaolinite,and smectite(including irregular mixed-layers of illite-smectite(I/S)and chloritesmectite(C/S)).The clay mineral assemblages and proxies exhibit three stages of change,which are mainly controlled by the Zoige watershed range under different climate *** watershed was limited to the southeastern region with altitudes ranging from~3500 to~4200 meters above sea level(m a.s.l.),and glacial-interglacial hydraulic erosion controlled the input of bedrock debris during 800-621 ka *** expanded to higher altitudes(~4200 to~4700 m a.s.l.)due to stronger seasonal freezethaw weathering without significant glacial-interglacial variations under a cooling and drying climate during 621-100 ka ***,it expanded to its highest altitudes of~4700 to~5200 m *** of the watershed after 100 ka BP,and hydraulic erosion increased obviously under a warm climate of the interstadial MIS 3 on the *** watershed underwent two major expansions under different climatic conditions at~621 ka and 100 ka BP,with the wet/dry alternation became strong at~621 ka *** results reveal that long-term temperature changes and the wet/dry alternation at high altitudes controlled the watershed range and degree of the physical erosion,and that the indications of clay minerals should be carefully clarified before they are used as climate indicators,especi

关键词： Quaternary Zoige Basin Lacustrine sediments Paleoenvironment Weathering

Density functional theory study of B- and Si-doped carbons and their adsorption interactions with sulfur compounds

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Carbon Energy 2024年第2期6卷 195-208页

作者： Peng guo Hong zhang Shuliang Dong Libao An College of Mechanical Engineering North China University of Science and TechnologyTangshanHebeiChina College of Life Sciences North China University of Science and TechnologyTangshanHebeiChina

Understanding the adsorption interactions between carbon materials and sulfur compounds has far-reaching impacts,in addition to their well-known important role in energy storage and conversion,such as lithium-ion *** this paper,properties of intrinsic B or Si single-atom doped,and B-Si codoped graphene(GR)and graphdiyne(GDY)were investigated by using density functional theory-based calculations,in which the optimal doping configurations were explored for potential applications in adsorbing sulfur *** showed that both B or Si single-atom doping and B-Si codoping could substantially enhance the electron transport properties of GR and GDY,improving their surface ***,B and Si atoms displayed synergistic effects for the codoped configurations,where B-Si codoped GR/GDY exhibited much better performance in the adsorption of sulfurcontaining chemicals than single-atom doped *** addition,results demonstrated that,after B-Si codoping,the adsorption energy and charge transfer amounts of GDY with sulfur compounds were much larger than those of GR,indicating that B-Si codoped GDY might be a favorable material for more effectively interacting with sulfur reagents.

关键词： adsorption density functional theory doping graphdiyne graphene sulfur compounds

Predictive model for non-malignant portal vein thrombosis associated with cirrhosis based on inflammatory biomarkers

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1213-1226页

作者： guo-Le Nie Jun Yan Ying Li Hong-long zhang Dan-Na Xie Xing-Wang Zhu Xun Li The First School of Clinical Medicine Lanzhou UniversityLanzhou 730000Gansu ProvinceChina Department of General Surgery The First Hospital of Lanzhou UniversityLanzhou 730000Gansu ProvinceChina

BACKGROUND Portal vein thrombosis(PVT),a complication of liver cirrhosis,is a major public health *** prediction is the most effective method for PVT diagnosis and *** To develop and validate a nomogram and network calculator based on clinical indicators to predict PVT in patients with *** Patients with cirrhosis hospitalized between January 2016 and December 2021 at the First Hospital of Lanzhou University were screened and 643 patients with cirrhosis who met the eligibility criteria were *** a 1:1 propensity score matching 572 patients with cirrhosis were screened,and relevant clinical data were *** risk factors were identified using the least absolute shrinkage and selection operator(LASSO)and multivariate logistic regression *** inflation factors and correlation matrix plots were used to analyze multicollinearity among the variables.A nomogram was constructed to predict the probability of PVT based on independent risk factors for PVT,and its predictive performance was verified using a receiver operating characteristic curve(ROC),calibration curves,and decision curve analysis(DCA).Finally,a network calculator was constructed based on the *** This study enrolled 286 cirrhosis patients with PVT and 286 without *** analysis revealed 13 variables as strongly associated with PVT *** logistic regression analysis revealed nine indicators as independent PVT risk factors,including etiology,ascites,gastroesophageal varices,platelet count,D-dimer,portal vein diameter,portal vein velocity,aspartate transaminase to neutrophil ratio index,and platelet-to-lymphocyte *** and correlation matrix plot results revealed no significant multicollinearity or correlation among the variables.A nomogram was constructed based on the screened independent risk *** nomogram had excellent predictive performance,with an area under the ROC curve of 0.821 and 0.829 in the

关键词： Portal vein thrombosis Liver cirrhosis Nomogram Inflammatory markers Aspartate aminotransferase to neutrophil ratio index Platelet-to-lymphocyte ratio

PUNet: A Semi-Supervised Anomaly Detection Model for Network Anomaly Detection Based on Positive Unlabeled Data

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Computers, Materials and Continua 2024年第1期81卷 327-343页

作者： long G. zhang Z. Faculty of Computing Harbin Institute of Technology Harbin 150000 China

Network anomaly detection plays a vital role in safeguarding network security. However, the existing network anomaly detection task is typically based on the one-class zero-positive scenario. This approach is susceptible to overfitting during the training process due to discrepancies in data distribution between the training set and the test set. This phenomenon is known as prediction drift. Additionally, the rarity of anomaly data, often masked by normal data, further complicates network anomaly detection. To address these challenges, we propose the PUNet network, which ingeniously combines the strengths of traditional machine learning and deep learning techniques for anomaly detection. Specifically, PUNet employs a reconstruction-based autoencoder to pre-train normal data, enabling the network to capture potential features and correlations within the data. Subsequently, PUNet integrates a sampling algorithm to construct a pseudo-label candidate set among the outliers based on the reconstruction loss of the samples. This approach effectively mitigates the prediction drift problem by incorporating abnormal samples. Furthermore, PUNet utilizes the CatBoost classifier for anomaly detection to tackle potential data imbalance issues within the candidate set. Extensive experimental evaluations demonstrate that PUNet effectively resolves the prediction drift and data imbalance problems, significantly outperforming competing methods. © 2024 The Authors. Published by Tech Science Press.

关键词： candidate set CatBoost Network anomaly detection representation learning

Effect of cerium alloying on microstructure,texture and mechanical properties of magnesium during cold-rolling process

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Journal of Rare Earths 2024年第5期42卷 1001-1008,I0007页

作者： Zhen zhang Huanhuan Chen Shiju Cao Jinhua Peng Peng guo Chang long Shan Wang Chang Chen Yong Wu Ji'an Huang Xiaodong Du Haigen Wei School of Materials Science and Engineering Hefei University of TechnologyHefei230009China NationalLocal Joint Research Center of Non-ferrous Metal Materials and Processing Technology Hefei230009China Laboratory of Nonferrous Metal Material and Processing Engineering of Anhui Province Hefei230009China School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212003China Institute of Industry and Equipment Technology Hefei University of TechnologyHefei230009China Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and TechnologyGanzhou341000China

Hot-extrusion and cold-rolling were conducted on Mg-Ce binary alloys to explore the effect of cerium(Ce)on microstructure,texture and mechanical properties of Mg *** addition of Ce results in significant grain refinement both in as-cast and hot-extruded *** basal texture is also weakened after extrusion and an inclined basal texture is formed with Ce *** strength and elongation of the Mg-Ce alloys are improved simultaneously due to such grain refinement and texture weakening *** cold-rolling,plenty of twins are found in the pure Mg and AZ31 plates while grains in the Mg-0.3Ce plate deform more uniformly without lamellar twin ***,Mg-0.3Ce alloys own strong and continuous strain hardening because Ce atoms and Mg-Ce precipitated phases serve as obstacles for dislocation slip.

关键词： Mg-Ce alloys Hot extrusion Cold-rolling Rare earths

Hybrid vibration isolation optimization of a flexible manipulator based on neural network agent model

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Chinese Journal of Aeronautics 2024年第5期37卷 482-505页

作者： Yongxin zhang Liang LI Dingguo zhang Wei-Hsin LIAO Xian guo School of Science Nanjing University of Science and TechnologyNanjing 210094China Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina

Segmented Active Constrained Layer Damping(SACLD)is an intelligent vibration-damping structure,which could be applied to the sectors of aviation,aerospace,and transportation engineering to reduce the vibration of flexible ***,machine learning technology is widely used in the engineering field because of its efficient multi-objective *** dynamic simulation of a rotational segmental flexible manipulator system is presented,in which enhanced active constrained layer damping is carried out,and the neural network model of Genetic Algorithm-Back Propagation(GA-BP)algorithm is *** suppression and structural optimization of the SACLD manipulator model are studied based on vibration mode and damping *** modal responses of the SACLD manipulator model at rest and rotation are *** addition,the four model indices are optimized using the GA-BP neural network:axial incision size,axial incision position,circumferential incision size,and circumferential incision ***,the best model for vibration suppression is obtained.

关键词： Machine learning Vibration suppression Flexible manipulator Segmented active constrained layer damping Structural optimization

The nitrogen transformation behavior based on the pyrolysis products of wheat straw

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Chinese Journal of Chemical Engineering 2024年第7期71卷 58-65页

作者： Shun guo Yunfei Li Shengwei Tang Tao zhang School of Chemical Engineering Sichuan UniversityChengdu 610065China

In order to provide basic design parameters for the industrial pyrolysis process,the transformation behavior of nitrogen was investigated using wheat straw as raw *** distributions of nitrogen in pyrolysis char,oil,and gas were obtained and the nitrogenous components in the products were analyzed systematically by X-ray photoelectron spectroscopy(XPS),pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and thermogravimetric-Fourier transform infrared spectrometry(TG-FTIR).The nitrogen distribution ranges of the pyrolysis char,oil,and gas were 37.34%–54.82%,32.87%–40.94%and 10.20%–28.83%,*** nitrogen was retained in char at lower pyrolysis temperature and the nitrogen distribution of oil was from rise to decline with increasing *** most abundant N-containing compounds in three-phase products were pyrrole-N,amines,and HCN,*** addition,the transformation mechanism of nitrogen from wheat straw to pyrolysis products was concluded.

关键词： Pyrolysis Nitrogen transformation Wheat straw Py-GC/MS TG-FTIR