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Importance of surface oxide for the tribology of a Zr-based metallic glass

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Friction 2017年第1期5卷 115-122页

作者： S.J.KANG K.T.RITTGEN S.G.KWAN H.W.PARK R.BENNEWITZ a.caron Department of Materials Sciences and Engineering Zhejiang University Hangzhou 310058 China NM-Leibniz Institute for New Materials Campus D2.2 Saarbrücken 66123 GermanyDepartment of Physics Saarland University Saarbrücken 66123 Germany KoreaTech Korea University of Technology and Education Chungnam Province 330-708 Republic of Korea NM-Leibniz Institute for New Materials Campus D2.2 Saarbrücken 66123 GermanyKoreaTech Korea University of Technology and Education Chungnam Province 330-708 Republic of Korea

Thermally grown surface oxide layers dominate the single-asperity tribological behavior of a Zr60Cu30Al10 *** in oxidation time leads to an increased contribution of shearing and a corresponding decreased contribution of ploughing to *** change in the dominating friction and wear mechanism results in an overall minor decrease of the friction coefficient of oxidized surfaces compared to the metallic glass sample with native surface *** results demonstrate the importance of creating a stable oxide layer for practical applications of metallic glasses in micro-devices involving sliding contact.

关键词： metallic glasses surface oxide friction wear nanotribology atomic force microscopy

分子世界里的海洋微生物生态学——未来的发展趋势

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海洋水产研究 2007年第6期28卷 83-96页

作者： David a.caron 李秋芬（译）唐启升（校） Department of Biological Sciences University of Southern California 3616 Trousdale Parkway AHF 301 Los Angiles CA 90089 0371 USA 农业部海洋生物资源可持续利用重点开放实验室中国水产科学研究院黄海水产研究所青岛266071

过去几十年中,遗传学和免疫学方法的进步改变了医学和生物制药学的研究。人类和几种模式生物的基因组已全部完成测序,这一遗传学信息财富的初步开发已经开始引起对这几种生物的研究及由此产生的应用的革命。得益于生物医学领域的技术进... 详细信息

过去几十年中,遗传学和免疫学方法的进步改变了医学和生物制药学的研究。人类和几种模式生物的基因组已全部完成测序,这一遗传学信息财富的初步开发已经开始引起对这几种生物的研究及由此产生的应用的革命。得益于生物医学领域的技术进步带来的巨大便利,对微生物(包括海洋微生物)生态学的理解也紧随其后。通过这些新方法、新技术的应用,海洋微生物生态学已经从20世纪50、60年代海洋生物学和生物海洋学的小脚注变成了我们对海洋的兴趣焦点。在过去的半个世纪中,我们学到了大量关于海洋中微生物的丰度、分布和活性的知识。由于认识到海洋微生物异常丰富的多样性、它们在全球生物地球化学过程中所起的主导作用以及天然和工程微生物产品给人类带来益处的潜力,它们已成为科研和公众关注的中心,而且人们对这些海洋中微小生物的迷恋也不会迅速消退。最新的研究表明,我们对海洋生态系中微生物多样性广度的了解相当有限,而且,自然界中许多、或者说大多数海洋微生物的优势种还没有被引入实验室培养。因此,我们对这些物种的生化、生理和行为能力的认识还是懵懂的,并且,在可预见的未来,海洋微生物研究还将是海洋科学研究的主要焦点。随着很多领域的研究者转向这项工作,我们可以期待海洋微生物群落组成和功能方面将会有更多的新发现和范例出现。

关键词：微生物生态学细菌原生生物生态基因组学分子分类学

Anomalous thermal expansion and enhanced magnetocaloric effect in<001>-textured Mn_(x)Fe_(5-x)Si_(3) alloys

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Rare Metals 2024年第5期43卷 2263-2274页

作者： Yong Gong Xue-Fei Miao Tapas Samanta Chris Taake Jun Liu Feng-Jiao Qian Yan-Yan Shao Yu-Jing Zhang Qing-Yong Ren Luana.caron Feng Xu MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing210094China Department of Physics Bielefeld University33501BielefeldGermany College of Physics Nanjing University of Aeronautics and AstronauticsNanjing210016China Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China Spallation Neutron Source Science Center Dongguan523803China Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology Dongguan523803China Department of Physics Bielefeld University33501BielefeldGermany Helmholtz-Zentrum Berlin für Materialien und Energie12489BerlinGermany

The development of zero and negative therma expansion(i.e.,ZTE and NTE)materials is of crucial importance to the control of undesirable thermal expansion for high-precision *** the present work,ZTE and NTE were obtained in directionally-solidified Mn_(x)Fe_(5-x)Si_(3)alloys with a strongtexture,in striking contrast to positive thermal expansion in their isotropic counterparts Magnetometry and in-situ X-ray diffraction(XRD)measurements were performed to uncover the origin of the anomalous thermal *** measurements indicate a strong easy-plane magnetocrystalline anisotropy in the textured samples,where the magnetic moments are aligned within the ab plane of the hexagonal structure Temperature-dependent XRD on the x=1 sample reveals a ZTE character in the ab plane that is coupled to a ferromagnetic *** a result,the macroscopic ZTE(~0.22×10^(-6)K^(-1))in the x=1 sample can be attributed to the microscopic magneto volume effect within the ab plane,which is realized by the introduction of the-textured ***,the competition between antiferromagnetic and ferromagnetic exchange coupling leads to NTE in textured x=1.5 and 2 ***,textured x=1 sample displays enhanced magnetocaloric properties as compared to the conventional counterparts with randomly-oriented *** this work demonstrates a new strategy toward the exploration of anomalous thermal expansion properties as well as the enhancement of magnetocaloric properties for materials with a strong magnetocrystalline anisotropy.

关键词： MnFeySis Magnetocaloric effect Magnetic phase transition Negative thermal expansion

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脑病:是职业性砷中毒的罕见病征吗?

环境与职业医学 1989年第3期13卷 67-67页

作者： Willian E.Morton Gordon a.caron 刘松影 md drphmbmrcp

砷剂是常见的刺激物,会引起接触组织如皮肤,胃肠道以及呼吸道的炎性反应。砷剂还具有接触性变应原的作用,以致较低的剂量都会使以前敏感的人出现反应。注意在足够量时,砷会通过在皮肤、肝、中枢神经系统、周围神经、动脉内皮、心肌以及... 详细信息

砷剂是常见的刺激物,会引起接触组织如皮肤,胃肠道以及呼吸道的炎性反应。砷剂还具有接触性变应原的作用,以致较低的剂量都会使以前敏感的人出现反应。注意在足够量时,砷会通过在皮肤、肝、中枢神经系统、周围神经、动脉内皮、心肌以及骨髓中的积蓄而产生有害作用。曾有报道慢性过量的砷吸收会使皮肤癌,肺癌,乳腺癌以及淋巴腺瘤的危险度增加。

关键词：砷中毒砷剂脑病淋巴腺瘤接触性变应原职业卫生中枢神经系统痛觉减退炎性反应神经精神病学

Deformation-and rupture-controlled friction between PDMS and a nanometer-scale SiO_(x) single-asperity

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Friction 2023年第9期11卷 1755-1770页

作者： Arnaud caron School of Energy Materials and Chemical EngineeringKoreaTech–Korea University of Technology and EducationCheonan 31253Republic of Korea

This work investigates the friction between polydimethylsiloxane(PDMS)and silicon oxide(SiO_(x))in single asperity sliding contact by atomic force microscopy(AFM).Two friction dependences on the normal force are identified:a tensile regime and a compressive regime of normal *** the compressive regime,friction is governed by the shear deformation and rupture of junctions between PDMS and SiO_(x).In this case,the shear strengthτ≈10 MPa is comparable with the cohesive strength of PDMS under compressive *** contrast,friction in the tensile regime is also affected by the elongation of the *** single SiO_(x)-asperity follows a stick–slip motion on PDMS in both normal force *** analysis of stick–slip as a function of the normal force allows determining the necessary amount of energy to break a SiO_(x)/PDMS *** between a SiO_(x)-asperity and a PDMS surface can be rationalized based on an energy criterion for the deformation and slippage of nanometer-scale junctions.

关键词： friction adhesion fracture atomic force microscopy(AFM) polydimethylsiloxane(PDMS)

A CK2-RNF4 interplay coordinates non-canonical SUMOylation and degradation of nuclear receptor FXR

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Journal of Molecular Cell Biology 2017年第3期9卷 195-208页

作者： Stephanie Bilodeau Veronique caron Jonathan Gagnon Alexandre Kuftedjian Andre Tremblay Research Center CHU Sainte-Justine Montreal Quebec H3T 1C5 Canada Department of Biochemistry and Molecular Medicine Faculty of Medicine University of Montreal Montreal Quebec H3T 1J4 Canada Department of Obstetrics & Gynecology Faculty of Medicine University of Montreal Montreal Quebec H3T 1J4 Canada

Farnesoid X receptor （FXR） is a ligand-activated nuclear receptor that plays a central role in regulating genes involved in bile acid homeostasis, and fat and glucose metabolism. Here, we demonstrate a post-translational interplay between FXR phosphoryl- ation, SUMOylation, and ubiquitination that directs the receptor into an activation-degradation pathway in hepatocytes. We iden- tify a non-canonical SUMOylation motif termed pSuM that conjugates SUM02 at Lys-325 of FXR under the direct control of casein kinase 2 （CK2）, which provides the required negative charge for Ubc9 and PIAS1 to perform SUMOylation, by phosphorylating Ser-327. Lys-325 SUMOylation is indispensable to the promotion of efficient ligand activation and transcriptional coactivation of FXR. Constitutive pSuM activation using a phospho-mimic Ser-327 mutant or catalytic CK2 expression strongly induces SUM02 conjugation, which directs FXR ubiquitination and proteasome-dependent degradation. We also determine that such SUMOylation-dependent ubiquitination of FXR is mediated by the E3 ubiquitin ligase RNF4, which is required to achieve maximal induction of FXR and optimal up- or downregulation of responsive genes involved in bile acid homeostasis and liver regeneration. Our findings identify a highly regulated atypical SUMO conjugation motif that serves to coordinate FXR transcriptional compe- tence, thereby expanding the intricate dynamics of the SUMOylation process used by incoming signals to govern metabolic gene regulation.

关键词： farnesoid receptor SUMOylation ubiquitination 26S proteasome bile acid

RESTful implementation of geospatial services for Earth and Space Science applications

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International Journal of Digital Earth 2009年第S01期2卷 40-61页

作者： P.Mazzetti S.Nativi J.caron Institute of Methodologies for Environmental Analysis(IMAA) Italian National Research Council(CNR)Tito ScaloItaly PIN University of FlorencePratoItaly UNIDATAUCAR P.O.Box 3000 Boulder CO 80307-3000USA

In recent years,Representational State Transfer(REST)has been proposed as the architectural style for the World Wide *** promises of scalability and simple deployment of Web Services seem to be particularly appealing for Earth and Space Science(ESS)*** fact,most of the available solutions for geospatial data sharing,applying standard interoperability specifications,require complex service-oriented infrastructures;these are powerful and extensible environments,but they usually result in difficult to deploy and manage for ESS research ***,ESS researchers would gain great benefit from an easy way of sharing geo-information using the international interoperability *** variety and complexity of geo-information sharing services poses several architectural issues;in fact these services encompass sensor planning and observation,coverages and features publication and retrieving,models and simulations running,data citation and ***,the adoption of a specific architectural style must be carefully evaluated against these specific *** this work we analyse the existing geospatial services from an architectural perspective and investigate their possible RESTful *** attention is paid to the OGC Web Coverage Service(WCS).Possible benefits and drawbacks,along with open issues and possible solutions are *** investigation suggests that REST may fit well to the typical ESS research usage ***,the architectural choice(*** Object Access Protocol(SOAP)vs REST)will depend on a case-by-case *** important factors must be considered,such as the application context:a valuable example in point are the e-Business and e-Government application scenarios which require message based solutions-like those implemented by *** any case,there is a clear need for harmonization and reconciliation of these two approaches.

关键词： geospatial web services ROA REST WCS SOA e-Science

Acid-base and lipophilic properties of peptide nucleic acid derivatives

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Journal of Pharmaceutical Analysis 2021年第5期11卷 638-645页

作者： Pramod Thakare Francesca Vasile Maura Vallaro Sonja Visentin Giulia.caron Emanuela Licandro Silvia Cauteruccio Department of Chemistry University of Milan20133MilanItaly Molecular Biotechnology&Health Sciences Department University of Turin10135TurinItaly

The first combined experimental and theoretical study on the ionization and lipophilic properties of peptide nucleic acid(PNA)derivatives,including eleven PNA monomers and two PNA decamers,is *** acidity constants(pKa)of individual acidic and basic centers of PNA monomers were measured by automated potentiometric pH titrations in water/methanol solution,and these values were found to be in agreement with those obtained by MoKa *** results indicate that single nucleobases do not change their pKa values when included in PNA monomers and *** addition,immobilized artificial membrane chromatography was employed to evaluate the lipophilic properties of PNA monomers and oligomers,which showed the PNA derivatives had poor affinity towards membrane phospholipids,and confirmed their scarce cell penetrating ***,our study not only is of potential relevance to evaluate the pharmacokinetic properties of PNA,but also constitutes a reliable basis to properly modify PNA to obtain mimics with enhanced cell penetration properties.

关键词： Peptide nucleic acids Ionization properties Potentiometric pH titration Immobilized artificial membrane chromatography Lipophilicity

Numerical sensitivity analysis of welding-induced residual stress depending on variations in continuous cooling transformation behavior

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Frontiers of Materials Science 2011年第2期5卷 168-178页

作者： C. HEINZE C. SCHWENK M. RETHMEIER J. caron Federal Institute for Materials Research and Testing Division 5.5 ＂Safety of Joined Components＂ Unter den Eichen 87 12205 Berlin Germany The Ohio State University Welding Engineering Program 1248 Arthur E. Adams Drive Columbus Ohio 43221 USA

The usage of continuous cooling transformation （CCT） diagrams in numerical welding simulations is state of the art. Nevertheless, specifications provide limits in chemical composition of materials which result in different CCT behavior and CCT diagrams, respectively. Therefore, it is necessary to analyze the influence of variations in CCT diagrams on the developing residual stresses. In the present paper, four CCT diagrams and their effect on numerical calculation of residual stresses are investigated for the widely used structural steel S355J2 ＋ N welded by the gas metal arc welding （GMAW） process. Rather than performing an arbitrary adjustment of CCT behavior, four justifiable data sets were used as input to the numerical calculation： data available in the Sysweld database, experimental data acquired through Gleeble dilatometry tests, and TTTICCT predictions calculated from the JMatPro and Edison Welding Institute （EWI） Virtual Joining Portal software. The performed numerical analyses resulted in noticeable deviations in residual stresses considering the different CCT diagrams. Furthermore, possibilities to improve the prediction of distortions and residual stress based on CCT behavior are discussed.

关键词： welding simulation GMAW CCT sensitivity welding residual stress