ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTDirect Growth of Single-Walled Carbon Nanotube Scanning Probe Microscopy TipsJason H. Hafner, Chin Li Cheung, and Charles M. LieberView Author Information Department of Chemistry and Chemical Biology Harvard University, Cambridge, Massachusetts 02138 Cite this: J. Am. Chem. Soc. 1999, 121, 41, 9750–9751Publication Date (Web):October 1, 1999Publication History Received3 August 1999Published online1 October 1999Published inissue 1 October 1999https://pubs.acs.org/doi/10.1021/ja992761bhttps://doi.org/10.1021/ja992761brapid-communicationACS PublicationsCopyright © 1999 American Chemical SocietyRequest reuse permissionsArticle Views1140Altmetric-Citations188LEARN 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 SUBJECTS:Carbon nanotubes,Catalysts,Chemical vapor deposition,Imaging,Probes Get e-Alerts
A class of phenomenological strain gradient plasticity theories is formulated to accommodate more than one material length parameter. The objective is a generalization of the classical J 2 flow theory of plasticity to account for strain gradient effects that emerge in deformation phenomena at the micron scale. A special case involves a single length parameter and is of similar form to that proposed by Aifantis and co-workers. Distinct computational advantages are associated with this class of theories that make them attractive for applications requiring the generation of numerical solutions. The higher-order nature of the theories is emphasized, involving both higher-order stresses and additional boundary conditions. Competing members in the class of theories will be examined in light of experimental data on wire torsion, sheet bending, indentation and other micron scale plasticity phenomena. The data strongly suggest that at least two distinct material length parameters must be introduced in any phenomenological gradient plasticity theory, one parameter characterizing problems for which stretch gradients are dominant and the other relevant to problems when rotation gradients (or shearing gradients) are controlling. Flow and deformation theory versions of the theory are highlighted that can accommodate multiple length parameters. Examination of several basic problems reveals that the new formulations predict quantitatively similar plastic behavior to the theory proposed earlier by the present authors. The new formulations improve on the earlier theory in the manner in which elastic and plastic strains are decomposed and in the representation of behavior in the elastic range.
In the years following the transfer of sovereignty from British to Chinese rule, the Hong Kong Special Administrative Region has consistently tried to maintain a reputation as a jurisdiction that enjoys an independent judiciary and the rule of law. However, over the past decade, a series of events in particular areas have challenged this perception. The status of refugees and how they are treated represents one such area. The status of asylum seekers has always been a matter of concern as Hong Kong has never been a signatory to the 1951 United Nations Convention Relating to the Status of Refugees. Additionally, recent court decisions regarding the question of non-refoulement and the absence of a government screening process for refugees make it increasingly difficult for observers to accept Hong Kong as a forward-looking, world-class city.This article examines recent decisions that deal with Hong Kong's obligations under international law regarding avoiding the ejection of refugees to jurisdictions where they will likely face persecution or torture. In particular, this article focuses on C. and Others v. Director of Immigration, in which Hong Kong's Court of First Instance considered whether an obligation of non-refoulement exists, and whether Hong Kong's government has a duty to provide a screening process to determine the status of all refugee claimants. Also explored is an earlier decision by Hong Kong's Court of Final Appeal, Secretary for Security v. Prabakar, in which a screening procedure for torture claimants was established.
This highly interdisciplinary 2007 book highlights many of the ways in which chemistry plays a crucial role in making life an evolutionary possibility in the universe. Cosmologists and particle physicists have often explored how the observed laws and constants of nature lie within a narrow range that allows complexity and life to evolve and adapt. Here, these anthropic considerations are diversified in a host of new ways to identify the most sensitive features of biochemistry and astrobiology. Celebrating the classic 1913 work of Lawrence J. Henderson, The Fitness of the Environment for Life, this book looks at the delicate balance between chemistry and the ambient conditions in the universe that permit complex chemical networks and structures to exist. It will appeal to a broad range of scientists, academics, and others interested in the origin and existence of life in our universe.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAttenuation lengths of photoelectrons in hydrocarbon filmsColin D. Bain and George M. WhitesidesCite this: J. Phys. Chem. 1989, 93, 4, 1670–1673Publication Date (Print):February 1, 1989Publication History Published online1 May 2002Published inissue 1 February 1989https://pubs.acs.org/doi/10.1021/j100341a095https://doi.org/10.1021/j100341a095research-articleACS PublicationsRequest reuse permissionsArticle Views888Altmetric-Citations236LEARN 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
Objectives. To review the contribution of the Nurses’ Health Studies (NHSs) to diet assessment methods and evidence-based nutritional policies and guidelines. Methods. We performed a narrative review of the publications of the NHS and NHS II between 1976 and 2016. Results. Through periodic assessment of diet by validated dietary questionnaires over 40 years, the NHSs have identified dietary determinants of diseases such as breast and other cancers; obesity; type 2 diabetes; cardiovascular, respiratory, and eye diseases; and neurodegenerative and mental health disorders. Nutritional biomarkers were assessed using blood, urine, and toenail samples. Robust findings, from the NHSs, together with evidence from other large cohorts and randomized dietary intervention trials, have contributed to the evidence base for developing dietary guidelines and nutritional policies to reduce intakes of trans fat, saturated fat, sugar-sweetened beverages, red and processed meats, and refined carbohydrates while promoting higher intake of healthy fats and carbohydrates and overall healthful dietary patterns. Conclusions. The long-term, periodically collected dietary data in the NHSs, with documented reliability and validity, have contributed extensively to our understanding of the dietary determinants of various diseases, informing dietary guidelines and shaping nutritional policy.
Liquid-core waveguides have the useful characteristic that the optical properties of the waveguides can be tailored by controlling the optical properties of the fluid in the core. This paper illustrates the use of soft-lithographic techniques to fabricate arrays of liquid-core waveguides by molding an organic polymer into a bas-relief structure and subsequently sealing this structure against a flat surface. The demonstrated ease of fabrication—combining soft lithography and rapid prototyping—may open the way for the fabrication of various optical devices based on microfluidic systems.
No abstract is provided for this article.