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Composition and size dependent torsion fracture of metallic glasses

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Journal of Materials Science & Technology 2021年第23期82卷 153-160页

作者： J.Dong J.Shen y.h.sun h.B.Ke B.A.sun W.h.Wang h.y.Bai Institute of Physics Chinese Academy of SciencesBeijing100190PR China College of Materials Science and Opto Electronic Technology University of Chinese Academy of SciencesBeijing100049PR China Songshan Lake Materials Laboratory DongguanGuangdong523808PR China

The fracture of metallic glasses(MGs)of different compositions and sizes down to micrometers under torsion loading were systematically *** to the flat shear fracture along the circumferential plane as commonly supposed under torsion,we find that the torsion fracture of metallic glasses can deviate from flat shear plane,and the fracture angle is closely dependent on the composition and the size of MG *** a conversion method,we show that the torsion fracture of both millimeterand micrometer-sized MGs can be described by the ellipse fracture criterion as originally proposed for the tension *** deviation from the circumferential shear plane under torsion is further shown to intrinsically relate to the fracture toughness of *** tougher MG tends to have a smaller fracture angle with respect to the maximum shear plane,and vice versa,indicating a correlation between the fracture toughness and pressure/normal stress sensitivity in *** results provide new insights on the fracture mechanism and are helpful to design and control the deformation and fracture behavior of MGs under torsion loading.

关键词： Metallic glasses Torsion fracture Pressure sensitivity Fracture toughness

Rotational and translational domains of beta precipitate in aged binary Mg-Ce alloys

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Journal of Magnesium and Alloys 2021年第3期9卷 1039-1056页

作者： B.Z.sun h.X.Zhang y.Dong J.X.Ren y.Tian G.M.Xie J.Tan y.h.sun Na Xiao School of Materials Science and Engineering Northeastern UniversityShenyang 110819China State Key Lab Rolling&Automat Northeastern UniversityShenyang 110819China Key Laboratory for Anisotropy and Texture of Materials Ministry of EducationNortheastern UniversityShenyang 110819China Analytical and Testing Center Northeastern UniversityShenyang 110819China

The structural evolution fromβ_(1)(Mg_(3)Ce)toβ(Mg_(12)Ce)precipitates,which takes place at the over-aged stage of binary Mg-Ce alloys,are investigated by high-angle annular dark-field scanning transmission electron *** structural transformation mainly occurs in the{111}_(β1)crystallographic planes,where the newly formedβlattices exhibit two categories of domain structures,namely rotational and translational *** rotational domain is composed of threeβdomains(β_(RA),β_(RB)andβ_(RC)),which are related by a 120°rotation with respect to each other around the 111_(β1)axis of theirβ_(1)parent ***{111}_(β1)crystallographic planes can provide four sets of sublattices with the same orientation for an initial nucleation ofβ*** leads to the formation of four translationalβdomains(β_(TA),β_(TB),β_(TC)andβ_(TD)),among which any two differ by a vector of 1/6112_(β1).We deduce theoretically that there exist twenty-fourβdomains during this ***,considering the interfacial misfit,only one-third of domains can grow up and eventually formsβ***,a majority ofβribbons overlap partiallyβ_(1)plate,which is beneficial to relax interfacial strain amongβ,β_(1)andα-Mg matrix(α/β/β_(1)).The configuration of multipleβdomains can effectively regulate interfacial misfit ofα/βandβ/β_(1),which are responsible for enhancing the hardness and strength of Mg-Ce ***,this study aims to provide some clues to improve the over-aged performance of magnesium alloys by constructingβdomains and optimizing theα/β/β_(1)interface.

关键词： Magnesium alloys hAADF-STEM Rotational domain Translational domain Phase transition Interfacial misfit

A negative deviation from Porod’s law in SAXS of organo—MSU—X

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Beijing Synchrotron Radiation Facility 2001年第2期 20-25页

作者： Z.h.Li y.J.Gong D.Wu y.h.sun J.Wang y.Liu B.Z.Dong y.J. LaboratoryofSynchrotronRadiation InstituteofHighEnergyPhysicschineseAcademyofSciencesP.O.Box165Beijing100039People’sRepublicofchina StateKeyLaboratoryofCoalConverison InstituteofCoalChemistryChi

Small-angle X-ray scattering(SAXS)using synchrotron radiation as X-ray source has been employed to charactcizc the microscopic structrure of organo-modified mesoporous molecular sieves(organo-MSU-X)prepared by a one-pot template-directed *** is shown that the SAXS profile is hardly constant with Porod’s law showing a negative slope,i.e.,negative *** suggests that there is diffuse interfacial layer located between the pores and the *** suggests that the organic groups remain covalently linked to the matrix,as indicated by ^29SiCP MAS NMR and *** average thickness of the interfacial layer was found to be about 1nm for each of the three samples with different kinds and the same amounts(20? of organic *** kind of material has also been proved to possess both surface and mass fractal structure of the amophous porous silica materials.2001 Elsevier Science *** rights reserved.

关键词：中孔材料 SAXS 小角X射线散射分析界面层结构特征有机中孔分子筛负偏差 Porod法

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湿气条件下的管道腐蚀

国外油田工程 2002年第8期18卷 46-47,54页

作者： y.h.sun 郑君黄红兵中国石油西南油气田分公司天然气研究院

在压力小于 1 82MPa、温度为 4 0℃时 ,测量了 10cm管径高压管道顶部和底部的二氧化碳(CO2 )湿气腐蚀速率。在气体流速小于 11m s和液体流速小于 0 2m s时 ,测定其流型。介质为去离子水和CO2 气体。在试验条件下的流型为环型或接近... 详细信息

在压力小于 1 82MPa、温度为 4 0℃时 ,测量了 10cm管径高压管道顶部和底部的二氧化碳(CO2 )湿气腐蚀速率。在气体流速小于 11m s和液体流速小于 0 2m s时 ,测定其流型。介质为去离子水和CO2 气体。在试验条件下的流型为环型或接近层状环流过渡区。在 3h后腐蚀速率趋于稳定且随气体流速、液体流速和CO2 分压的增加而增长。试验结果可应用于油田条件。

关键词：湿气条件管道腐蚀油气管道二氧化碳腐蚀速率

hWD-yOLO: A New Vision-Based helmet Wearing Detection Method

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Computers, Materials and Continua 2024年第3期80卷 4543-4560页

作者： sun L. Li h. Wang L. College of Information Science and Technology Beijing University of Technology Beijing 100124 China Chinese Institute of Coal Science Beijing 100013 China State Key Laboratory for Intelligent Coal Mining and Strata Control Beijing 100013 China Engineering Research Center of Digital Community of Ministry of Education Beijing 100124 China

It is crucial to ensure workers wear safety helmets when working at a workplace with a high risk of safety accidents, such as construction sites and mine tunnels. Although existing methods can achieve helmet detection in images, their accuracy and speed still need improvements since complex, cluttered, and large-scale scenes of real workplaces cause server occlusion, illumination change, scale variation, and perspective distortion. So, a new safety helmet-wearing detection method based on deep learning is proposed. Firstly, a new multi-scale contextual aggregation module is proposed to aggregate multi-scale feature information globally and highlight the details of concerned objects in the backbone part of the deep neural network. Secondly, a new detection block combining the dilate convolution and attention mechanism is proposed and introduced into the prediction part. This block can effectively extract deep features while retaining information on fine-grained details, such as edges and small objects. Moreover, some newly emerged modules are incorporated into the proposed network to improve safety helmet-wearing detection performance further. Extensive experiments on open dataset validate the proposed method. It reaches better performance on helmet-wearing detection and even outperforms the state-of-the-art method. To be more specific, the mAP increases by 3.4%, and the speed increases from 17 to 33 fps in comparison with the baseline, you Only Look Once (yOLO) version 5X, and the mean average precision increases by 1.0% and the speed increases by 7 fps in comparison with the yOLO version 7. The generalization ability and portability experiment results show that the proposed improvements could serve as a springboard for deep neural network design to improve object detection performance in complex scenarios. Copyright © 2024 The Authors. Published by Tech Science Press.

关键词： attention mechanism deep learning feature extraction Object detection safety helmet wearing detection

Schisanhenol ameliorates non-alcoholic fatty liver disease via inhibiting miR-802 activation of AMPK-mediated modulation of hepatic lipid metabolism

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Acta Pharmaceutica Sinica B 2024年第9期14卷 3949-3963页

作者： Li B. Xiao Q. Zhao h. Zhang J. yang C. Zou y. Zhang B. Liu J. sun h. Liu h. State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Medicinal Plant Development Chinese Academy of Medical Sciences Peking Union Medical College Beijing 100193 China Institute of Basic Medical Sciences Chinese Academy of Medical Sciences Department of Pathophysiology Peking Union Medical College Beijing 100005 China

Non-alcoholic fatty liver disease (NAFLD), characterized by hepatic steatosis, is a common metabolic liver disease worldwide. Currently, satisfactory drugs for NAFLD treatment remain lacking. Obesity and diabetes are the leading causes of NAFLD, and compounds with anti-obesity and anti-diabetic activities are considered suitable candidates for treating NAFLD. In this study, biochemical and histological assays revealed that a natural lignan schisanhenol (SAL) effectively decreased lipid accumulation and improved hepatic steatosis in free fatty acid (FFA)-treated hepG2 cells and high-fat diet (hFD)-induced NAFLD mice. Further, molecular analyses, microRNA (miRNA)-seq, and bioinformatics analyses revealed that SAL may improve NAFLD by targeting the miR-802/adenosine monophosphate-activated protein kinase (AMPK) pathway. Liver-specific overexpression of miR-802 in NAFLD mice significantly impaired SAL-mediated liver protection and decreased the protein levels of phosphorylated (p)-AMPK and PRKAB1. Dual-luciferase assay analysis further confirmed that miR-802 inhibits hepatic AMPK expression by binding to the 3' untranslated region of mouse Prkab1 or human PRKAA1. Additionally, genetic silencing of PRKAA1 blocked SAL-induced AMPK pathway activation in FFA-treated hepG2 cells. The results demonstrate that SAL is an effective drug candidate for treating NAFLD through regulating miR-802/AMPK-mediated lipid metabolism. © 2024 The Authors

关键词： AMPK hepatic steatosis Lipid metabolism miR-802 Non-alcoholic fatty liver disease PPARα Schisanhenol SREBP-1c

Impact of effective stress on permeability for carbonate fractured-vuggy rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 942-960页

作者： Ke sun huiqing Liu Juliana y.Leung Jing Wang yabin Feng Renjie Liu Zhijiang Kang yun Zhang State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China School of Mining&Petroleum Engineering University of AlbertaEdmontonT6G 1H9Canada SINOPEC Petroleum Exploration and Production Research Institute Beijing100083China

To gain insight into the flow mechanisms and stress sensitivity for fractured-vuggy reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of effective stress on permeability for carbonate fractured-vuggy rocks(CFVR).It shows that the permeability performance curves under different pore and confining pressures(*** stress conditions)for the fractured core models and the vuggy core models have similar change *** ranges of permeability variation are significantly wider at high pore pressures,indicating that permeability reduction is the most significant during the early stage of development for fractured-vuggy *** each obtained effective stress coefficient for permeability(ESCP)varies with the changes in confining pressure and pore pressure,the effective stresses for permeability of four representative CFVR show obvious nonlinear characteristics,and the variation ranges of ESCP are all between 0 and ***,a comprehensive ESCP mathematical model considering triple media,including matrix pores,fractures,and dissolved vugs,was *** is proved theoretically that the ESCP of CFVR generally varies between 0 and ***,the regression results showed that the power model ranked highest among the four empirical models mainly applied in stress sensitivity characterization,followed by the logarithmic model,exponential model,and binomial *** concept of“permeability decline rate”was introduced to better evaluate the stress sensitivity performance for CFVR,in which the one-fracture rock is the strongest,followed by the fracture-vug rock and two-horizontalfracture rock;the through-hole rock is the *** general,this study provides a theoretical basis to guide the design of development and adjustment programs for carbonate fractured-vuggy reservoirs.

关键词： Effective stress Permeability Carbonate fractured-vuggy rocks Structure characteristics Stress sensitivity

The Functional Redundancy of Neddylation E2s and E3s in Modulating the Fitness of Regulatory T Cells

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Research 2024年第2期2023卷 373-387页

作者： Di Wu yi sun Cancer Institute(Key Laboratory of Cancer Prevention and Intervention China National Ministry of Education)of the Second Affiliated Hospital and Institute of Translational MedicineZhejiang University School of MedicineHangzhou 310029China Cancer Center of Zhejiang University Hangzhou 310029China Zhejang Provincial Clinical Research Center for Cancer Zhejang ProvinceChina Key Laboratory of Molecular Biology in Medical Sciences Zhejang ProvinceChina Research Center for Life Science and human health Binjiang Institute of Zhejiang UniversityHangzhou 310053China

Neddylation is necessary for activation of Cullin-RING ligases(CRLs),which degrade various immune regulatory *** recent study showed that while depletion of neddylation E2-E3 pair Ube2f-Sag in regulatory T(T_(reg))cells had no obvious phenotype,the same depletion of either Ube2m or Rbx1 caused inflammation disorders with different *** these E2s or E3s compensate each other in functional regulations of T_(reg)cells is,however,previously *** this report,we generated Foxp3^(Cre);Ube2m^(fl/fl);Ube2f^(fl/fl)or Foxp3^(Cre);Rbx1^(fl/fl);Sag^(fl/fl)double-null mice by simultaneous deletion of both neddylation E2s or E3s in T_(reg)cells,***,Ube2m&Ube2f double-null mice developed much severe autoimmune phenotypes than did Ube2m-null mice,indicating that Ube2m markedly compensates Ube2f in T_(reg)*** minor worsened autoimmune phenotypes seen at the very early stage in Rbx1&Sag double-null than Rbx1-null mice is likely due to already severe phenotypes of the later,indicating a minor compensation of Rbx1 for *** RNA profiling-based analyses revealed that up-and down-regulations of few signaling pathways in T_(reg)cells are associated with the severity of autoimmune ***,severer inflammation phenotypes seen in mice with double E3-null than with double E2-null T_(reg)cells indicate a neddylation-independent mechanism of 2 E3s,also known to serve as the RING component of CRLs in regulation of T_(reg)cell fitness.

关键词： Foxp3 inflammation markedly

NiO-Doped Fe_(2)O_(3)/MgO Properties for the Chemical Looping Oxidative Dehydrogenation of Ethane

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 27-33页

作者： Liang hao Chen Junjie sun Jie sun hui Shenyang Ligong University Shenyang 110159China Fushun Ecology Environment Bureau Qingyuan County Branch Fushun 113399China

Ethane chemical looping oxidative dehydrogenation(CL-ODh)to ethylene is a new technology for ethylene ***_(2)O_(3)/MgO oxygen carrier was prepared using the co-precipitation *** influence of added NiO and its different loadings on Fe_(2)O_(3)/MgO were ***,a series of oxygen carriers were applied in the CL-ODh of the ethane cycle ***-Emmett-Teller(BET),X-ray diffractometry(XRD),X-ray photoelection spectroscopy(XPS),and h2-temperature programmed reduction(TPR)were used to characterize the physicochemical properties of these oxygen *** was confirmed that an interaction between NiO and Fe_(2)O_(3) occurred based on the XPS and h2-TPR *** on the CL-ODh activity performance tests conducted in a fixed-bed reactor,it was revealed that ethylene selectivity was significantly improved after NiO ***_(2)O_(3)-10%NiO/MgO showed the best activity performance with 93%ethane conversion and 50%ethylene selectivity at a reaction temperature of 650℃,atmospheric pressure,and space velocity of 7500 mL/(g·h).

关键词： chemical looping oxidative dehydrogenation oxygen carrier Fe_(2)O_(3)/MgO NiO