Atomic force microscopy has been used to characterize wear and oxidation of transition metal dichalcogenide surfaces. Sequential images recorded on molybdenum disulfide (MoS2) and niobium diselenide (NbSe2) surfaces show that wear proceeds at defects, and that MoS2 wears at least five times more slowly than NbSe2. Images of thermally treated MoS2 and NbSe2 further demonstrate that oxidation creates surface defects on both materials. However, for similar oxidation conditions, NbSe2 surfaces show extensive degradation, while MoS2 surfaces only exhibit isolated defects. The implications of these results to understanding the tribological properties of the transition metal dichalcogenides are discussed.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAttenuation of photoelectrons in monolayers of n-alkanethiols adsorbed on copper, silver, and goldPaul E. Laibinis, Colin D. Bain, and George M. WhitesidesCite this: J. Phys. Chem. 1991, 95, 18, 7017–7021Publication Date (Print):September 1, 1991Publication History Published online1 May 2002Published inissue 1 September 1991https://pubs.acs.org/doi/10.1021/j100171a054https://doi.org/10.1021/j100171a054research-articleACS PublicationsRequest reuse permissionsArticle Views1470Altmetric-Citations292LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of a water-soluble derivative of cyclohexatriacontane-1,2,13,14,25,26-hexoneW. Harry Mandeville and George M. WhitesidesCite this: J. Org. Chem. 1986, 51, 17, 3257–3261Publication Date (Print):August 1, 1986Publication History Published online1 May 2002Published inissue 1 August 1986https://pubs.acs.org/doi/10.1021/jo00367a002https://doi.org/10.1021/jo00367a002research-articleACS PublicationsRequest reuse permissionsArticle Views322Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Electronic skins (i.e., stretchable sheets of distributed sensors) report signals using electrons, whereas natural skins report signals using ions. Here, ionic conductors are used to create a new type of sensory sheet, called "ionic skin". Ionic skins are highly stretchable, transparent, and biocompatible. They readily measure strains from 1% to 500%, and pressures as low as 1 kPa. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Pulsed laser ablation of graphite targets combined with an intense, atomic nitrogen source has been used to prepare C-N thin film materials. The average nitrogen content in the films was systematically varied by controlling atomic nitrogen flux. Rutherford backscattering measurements show that up to 40 percent nitrogen can be incorporated on average into these solids under the present reaction conditions. Photoelectron spectroscopy further indicates that carbon and nitrogen form an unpolarized covalent bond in these C-N materials. Qualitative tests indicate that the C-N solids are thermally robust and hard. In addition, strong electron diffraction is observed from crystallites within the films. Notably, analysis of these diffraction data show that the only viable structure for the C-N crystallites is that of β-C 3 N 4 , a material predicted theoretically to exhibit superhardness. The experimental synthesis of this new C-N material offers exciting prospects for both basic research and engineering applications.
Überall in der Biologie kommen polyvalente Wechselwirkungen vor. Sie zeichnen sich durch die gleichzeitige Bindung mehrerer Liganden einer biologischen Einheit an mehrere Rezeptoren einer anderen biologischen Einheit aus (oberer Teil der Graphik) und haben eine Reihe von Charakteristika, die monovalenten Wechselwirkungen fehlen (unten). Besonders im Verbund können polyvalente Wechselwirkungen viel stärker sein als entsprechende monovalente Wechselwirkungen, und sie können die Basis für das Verständnis fördernder und hemmender biologischer Wechselwirkungen liefern, die sich grundsätzlich von denen in monovalenten Systemen unterscheiden.