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Penetration performance of W/Cu double-layer shaped charge liners

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Rare Metals 2016年第2期35卷 184-191页

作者： wen-Jian Dong Jin-xu Liu Xing-Wang Cheng Shu-Kui Li qing-He Zou wen-qi Guo School of Materials Science and Engineering Beijing Institute of Technology Mudanjiang North Alloy Tool Co. Ltd.

Two kinds of W/Cu double-layer shaped charge liner（SCL） were prepared by chemical vapor deposition（CVD） combined with electroforming technique： A SCL with W inner layer and Cu outer layer, B SCL with Cu inner layer and W outer layer. The penetration properties of A and B SCLs were researched. The results show that the two SCLs can form continuous jet and the tip velocities of A and B jets are 7.4 and 6.3 km s^（-1）, respectively. The kinetic energy density（5.3 9 1011 J m-3） of A jet tip increases by 194.4 %compared with that（1.8 9 1011 J m-3） of B jet tip. B jet,however, exhibits deeper penetration depth at the same experimental conditions. The chemical component and microstructure of the area nearby the ballistic perforation were researched. Component analysis shows that both the jets are formed only from inner layer metal. Microstructure analysis shows that martensite and intermetallic form around ballistic perforation penetrated by A SCL due to the intensive interaction between W jet and steel target. The two kinds of newly formed ultrahard phases also hinder the jet from penetrating target further. As a result of relatively alleviative interaction between Cu jet and target, only solid solution rather than ultrahard phases forms around ballistic perforation penetrated by B SCL.

关键词： Shaped charge liner Jet Penetration performance Chemical vapor deposition Electroforming technique

不同干细胞来源外泌体及其携非编码RNA诊疗骨性关节炎

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中国组织工程研究 2025年第19期29卷 4122-4131页

作者：王喆齐岩松徐永胜内蒙古自治区人民医院骨科中心(运动医学中心) 内蒙古自治区呼和浩特市010017

背景:外泌体可在骨性关节炎患者滑液和血浆中检测出来,其水平随着骨性关节炎的进展而不断变化,并且可以对骨性关节炎的局部炎症、软骨钙化和关节退化起缓解作用。目的:旨在全面了解不同干细胞来源外泌体在骨性关节炎诊疗中的作用和机制... 详细信息

背景:外泌体可在骨性关节炎患者滑液和血浆中检测出来,其水平随着骨性关节炎的进展而不断变化,并且可以对骨性关节炎的局部炎症、软骨钙化和关节退化起缓解作用。目的:旨在全面了解不同干细胞来源外泌体在骨性关节炎诊疗中的作用和机制,并提出了外泌体治疗骨性关节炎的前景和挑战。方法:检索PubMed及中国知网数据库,英文检索词为“exosomes,osteoarthritis,mesenchymal stem cells,stem cells”,中文检索词为“外泌体,骨性关节炎,间充质干细胞,干细胞”,对2003年10月至2023年10月发表的文献进行检索,最终纳入99篇文献进行综述。结果与结论:外泌体的出现给骨性关节炎的诊断和治疗带来了希望。外泌体内含RNA、蛋白质及脂类的差异能够作为骨性关节炎的生物标志物用于诊断。同时,来自不同干细胞的外泌体均能够有效保护软骨细胞、缓解炎症、维持软骨基质代谢以及调节血管生成和软骨下骨重塑,表现出治疗骨性关节炎的优秀潜力。工程化外泌体则突破传统局限,通过调节特定非编码RNA表达增强治疗特异性与效率,为骨性关节炎的治疗提供新策略。

关键词：外泌体骨性关节炎间充质干细胞干细胞软骨修复软骨再生软骨细胞 RNA 工程化外泌体

Effect of Phase Separation Size on the Properties of Self-healing Elastomer

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Chinese Journal of Polymer Science 2024年第6期42卷 798-804页

作者： Jun xu Lei Zhu Xian-qi Feng Cong Sui wen-Peng Zhao Shou-Ke Yan School of Chemical Engineering Qingdao University of Science&TechnologyQingdao266042China College of Engineering Yanching institute of TechnologyLangfang065210China Key Laboratory of Rubber-plastics Qingdao University of Science&TechnologyQingdao266042China State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China

Regulation of phase structure has been recognized as one of the most effective ways to fabricate self-healing polymers with high mechanical *** mechanical properties of the resultant polymers are certainly affected by the size of separated phase ***,the study on this aspect is absence,because it can hardly exclude the influence of variation in monomer proportion required for tuning the separated phase ***,we report the first study on tuning the phase size through reversible addition-fragmentation chain transfer(RAFT)polymerization without changing the proportion of *** expected,the size of separated phase has been successfully mediated from 15 nm to 9 nm by tuning the molecular weight of the chain transfer *** is found that the mechanical strength and the self-healing efficiency of the resultant polymers increase simultaneously with the decrease of phase *** study on the formation kinetics of hydrogen bonds reveals that the decrease of phase size can facilitate the re-bonding rate of hydrogen bonds,even if the migration of polymer chains is restricted.

关键词： Self-healing polymers Phase separation Reversible addition-fragmentation chain transfer

Surface Roughness and Roundness of Bearing Raceway Machined by Floating Abrasive Polishing and Their Effects on Bearing's Running Noise

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Chinese Journal of Mechanical Engineering 2014年第3期27卷 543-550页

作者： PANG Guibing qi xuezhi MA qinyi ZHAO Xiujun wen Chunsheng xu wenji PENG Yanping School of Mechanical Engineering and Automation Dalian Polytechnic University Dalian Wazhou Precision Motor & Automobile Bearing Co. ltd School of Mechanical Engineering Dalian University of Technology

As the two most important indexes of bearing raceway, surface roughness and roundness have significant influence on bearing noise. Some researchers have carried out studies in this field, however, reason and extent of the influence of raceway surface geometric characteristics on bearing running noise are not perfectly clear up to now. In this paper, the raceway of 6309 type bearing＇s inner and outer ring is machined by floating abrasive polishing adopting soft abrasive pad. Surface roughness parameters, arithmetical mean deviation of the profile Ra, the point height of irregularities Rz, maximum height of the profile Rmax and roundness fof raceways, are measured before and after machining, and the change rules of the measured results are studied. The study results show that the floating abrasive polishing can reduce the surface geometric errors of bearing raceway evidently. The roundness error is reduced by 25%, Rm^x value is reduced by 35.5%, Rz value is reduced by 22% and Ra value is reduced by 5%. By analyzing the change of the geometrical parameters and the shape difference of the raceway before and after machining, it is found that the floating abrasive polishing method can affect the roundness error mainly by modifying the local deviation of the raceway＇s surface profile. Bearings with different raceway surface geometrical parameter value are assembled and the running noise is tested. The test results show that Ra has a little, Rmax and Rz have a measurable, and the roundness error has a significant influence on the running noise. From the viewpoint of controlling bearings＇ running noise, raceway roundness error should be strictly controlled, and for the surface roughness parameters, R,n^x and Rz should be mainly controlled. This paper proposes an effective method to obtain the low noise bearing by machining the raceway with floating abrasive polishing after super finishing.

关键词： surface roughness roundness polishing lapping bearing raceway noise

Composite Scattering from an Arbitrary Dielectric Target above the Dielectric Rough Surface with FEM/PML

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Chinese Physics Letters 2013年第12期30卷 37-41页

作者： xu Run-wen GUO Li-Xin FAN Tian-qi School of Science Xidian UniversityXi'an 710071

A numerical approach of the finite element method is extended to study the scattering properties of an arbitrary dielectric target above the dielectric rough *** scattering in an open region,the artificial boundaries should be introduced to truncate the infinite computational domain.A perfectly matched layer(PML),as the artificial boundary of the finite-element-method(FEM)region,is employed to absorb the outward wave scattered from the *** strategies of hybrid FEM/PML are presented with their validity evaluated by finite element/boundary integral method(FE/BIM),and then the scattering properties of the dielectric composite problem with different material permittivity are discussed in *** with the published works about FEM/PML,we extend the FEM/PML into the simulations of a dielectric target above the dielectric rough surface.

关键词： surface dielectric element

A multi-omics study on cutaneous and uveal melanoma

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International Journal of Ophthalmology(English edition) 2021年第1期14卷 32-41页

作者： qi Zhang Ze-Nan Lin Jie Chen wen-xu Zheng Institute of Pathology and Neuropathology University of TuebingenTuebingen 72076Germany University Eye Hospital Center for OphthalmologyUniversity of TuebingenTuebingen 72076Germany Department of Ophthalmology Shanghai East HospitalTongji University School of MedicineShanghai 200120China Department of Ophthalmology the Second Hospital Affiliated to Jilin UniversityJilin UniversityChangchun 130041Jilin ProvinceChina

AIM:To present the multi-omics landscape of cutaneous melanoma(CM)and uveal melanoma(UM)from The Cancer Genome Atlas(TCGA).METHODS:The differentially expressed genes(DEGs)between CM and UM were found and integrated into a gene ontology enrichment ***,the differentially expressed miRNAs were also *** also compared the methylation level of CM with UM and identified the differentially methylated regions to integrate with the DEGs to display the relationship between the gene expression and DNA *** differentially expressed transcription factors(TFs)were ***:Though CM had more mutational burden than UM,they shared several similarities such as the same rankings in diverse variant *** GNAQ and GNA11,the other top 18 mutated genes of the combined group were mostly detected in CM instead of *** the transcriptomic level,4610 DEGs were found and integrated into a gene ontology enrichment *** also identified 485 differentially expressed *** methylation analysis showed that UM had a significantly higher methylation level than *** integration of differentially methylated regions and DEGs demonstrated that most DEGs were downregulated in UM and the hypo-and hypermethylation presented no obvious difference within these ***,116 hypermethylated TFs and 114 hypomethylated TFs were identified as differentially expressed TFs in CM when compared with ***:This multi-omics study on comparing CM with UM confirms that they differ in all analyzed *** notice,the results also offer new insights with implications for elucidating certain unclear problems such as the distinct role of epithelial mesenchymal transition in two melanomas,the different metastatic routes of CM and UM and the liver tropism of metastatic UM.

关键词： cutaneous melanoma uveal melanoma genomics transcriptomics epigenetics

Comparison between double caliper,imaging logs,and array sonic log for determining the in-situ stress direction:A case study from the ultra-deep fractured tight sandstone reservoirs,the Cretaceous Bashijiqike Formation in Keshen8 region of Kuqa depress

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Petroleum Science 2022年第6期19卷 2601-2617页

作者： Song Wang Gui-wen Wang Dong Li Xing-Neng Wu xu Chen qi-qi Wang Jun-Tao Cao Yi-Lin Zhang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum BeijingBeijing102249China College of Geosciences China University of Petroleum BeijingBeijing102249China Research Institute of Petroleum Exploration and Development Tarim Oilfield CompanyCNPCKorla841000XinjiangChina Department of Geological Sciences University of Texas at Austin2275 Speedway Stop C9000AustinTX78712USA

The tight sandstone in the Tarim Basin has the characteristics of large burial depth and development of nature fractures due to concentrated in-situ stress. Identifying the present-day in-situ stress orientation is important in hydrocarbon exploration and development, but also a key scientific question in understanding naturally fractured reservoirs. This paper presents a case study where we integrate various methods using wireline and image-log data, to identify present-day in-situ stress direction of ultra-deep fractured tight sandstone reservoirs, in the Kuqa depression. We discuss the formation mechanism of the elliptical borehole, compares the advantages and applicable conditions of the double caliper method,resistivity image logs and array sonic logs method. The well borehole diameter is measured orthogonally,then the ellipse is fitted, and the in-situ stress orientation is identified by the azimuth of the short-axis borehole, but it fails in the borehole expansion section, the fracture development section and the borehole collapse section. The micro-resistivity image logs method reveals the borehole breakouts azimuth, and also the strike of induced fractures, which are used to determine the orientation of in-situ stress. However, under water-based mud conditions, it’s hard to distinguish natural fractures from induced fractures by image logs. Under oil-based mud conditions, the induced fractures are difficult to identify due to the compromised image quality. As for the sonic log, shear waves will split when passing through an anisotropic formation, shear waves will split during propagation, and the azimuth of fast shear waves is consistent with the orientation of in-situ stress. However, it is usually affected by the anisotropy caused by the excessively fast rotation of the well log tools, so that the azimuth of fast shear wave cannot effectively reflect the orientation of the in-situ stress. Based on comprehensive assessment and comparison, in this paper we

关键词： Fractured tight sandstone In-situ stress Orientation Well logs

Analytical method of dynamic properties of FRP based on micromechanical level

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Chinese Journal of Aeronautics 2015年第3期28卷 939-945页

作者： qi wenkai xu Xiaoqiang College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Jiangsu Province Key Laboratory of Aerospace Power System

Abstract A mathematic model is proposed for predicting the dynamic properties of fiber reinforced plastic composites （FRP） with interphase. Dynamic properties mainly include loss factors and elastic moduli. The results of elastic moduli fi＇om the present model are compared with other models. Elastic moduli Ell, E22, G12, G23 and loss factors ηll, η22, ηl2 and η23 of FRP are calculated and a study of the effect of elastic modulus Ej and loss factor rh ofinterphase on dynamic properties in FRP is carried out here. In this paper, E11 linearly increases with El, but the growth rate is slow. E22, G12, G23 increase rapidly for lower value of EI. The longitudinal loss factor E1 decreases with the increase of El in the case of rh 〈 0.0026. But η11 linearly increases with E1 in larger range of η1, η1 〉 0.0026. On the contrary, transverse loss factor η22, transverse shear loss factors r/23 and longitudinal shear loss factors η12 increase with increase of E1 in the case of lower value of η1, but decreases at larger value of ηl. And they also show insensitivity to E1 at higher value.

关键词： Bridging model Complex moduliFRP Interphase Loss factor

Stress-state dependence of dynamic strain aging:Thermal hardening and blue brittleness

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International Journal of Minerals,Metallurgy and Materials 2021年第5期28卷 854-866页

作者： wen-qi Liu Jun-he Lian Advanced Manufacturing and Materials Department of Mechanical EngineeringAalto UniversityPuumiehenkuja 302150 EspooFinland Impact and Crashworthiness Lab Department of Mechanical EngineeringMassachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA 02139-4307USA

This study aims to discover the stress-state dependence of the dynamic strain aging(DSA)effect on the deformation and fracture behavior of high-strength dual-phase(DP)steel at different deformation temperatures(25-400°C)and reveal the damage mechanisms under these various *** achieve different stress states,predesigned specimens with different geometric features were *** electron microscopy was applied to analyze the fracture modes(e.g.,dimple or shear mode)and underlying damage mechanism of the investigated *** is present in this DP steel,showing the Portevin-Le Chatelier(PLC)effect with serrated flow behavior,thermal hardening,and blue brittleness *** show that the stress state contributes distinctly to the DSA effect in terms of the magnitude of thermal hardening and the pattern of blue *** low stress triaxiality or Lode angle parameter promotes DSA-induced blue ***,the damage mechanisms also show dependence on the stress states in conjunction with the DSA effect.

关键词： dynamic strain aging effect Portevin-Le Chatelier effect damage mechanism dimple fracture shear fracture dual-phase steel