5,365 research outputs found
A simple unsymmetric 4‐node 12‐DOF membrane element for the modified couple stress theory
In this work, the recently proposed unsymmetric 4‐node 12‐DOF (degree‐of‐freedom) membrane element (Shang and Ouyang, Int J Numer Methods Eng 113(10): 1589‐1606, 2018), which has demonstrated excellent performance for the classical elastic problems, is further extended for the modified couple stress theory, to account for the size effect of materials. This is achieved via two formulation developments. Firstly, by using the penalty function method, the kinematic relations between the element's nodal drilling DOFs and the true physical rotations are enforced. Consequently, the continuity requirement for the modified couple stress theory is satisfied in weak sense, and the symmetric curvature test function can be easily derived from the gradients of the drilling DOFs. Secondly, the couple stress field that satisfies a priori the related equilibrium equations is adopted as the energy conjugate trial function to formulate the element for the modified couple stress theory. As demonstrated by a series of benchmark tests, the new element can efficiently capture the size‐dependent responses of materials and is robust to mesh distortions. Moreover, as the new element uses only three conventional DOFs per node, it can be readily incorporated into the standard finite element program framework and commonly available finite element programs
Soliton interaction in a fiber ring laser
Author name used in this publication: H. Y. Tam2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Pulse breaking recovery in fiber lasers
Author name used in this publication: H. Y. TamAuthor name used in this publication: C. Lu2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Gain-guided solitons in dispersion-managed fiber lasers with large net cavity dispersion
Author name used in this publication: C. Lu2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Induced solitons formed by cross-polarization coupling in a birefringent cavity fiber laser
Author name used in this publication: H. Y. TamVersion of RecordPublishe
Telocytes in pleura: two- and three-dimensional imaging by transmission electron microscopy
Information about the ultrastructure of connective (interstitial) cells supporting the pleural mesothelium is scarce. Our aim has been to examine whether telocytes (TCs) are present in pleura, as in epicardium and mesentery. TCs are a distinct type of cell, characterized by specific prolongations named telopodes (Tp). We have used transmission electron microscopy (TEM) and electron tomography (ET) to determine whether ultrastructural diagnostic criteria accepted for TCs are fulfilled by any of the cell subpopulations existing in the sub-mesothelial layer in mouse and human pleura. TCs have been identified with TEM by their characteristic prolongations. Tp appear long and moniliform, because of the alternation of podomeres (thin segments of less than 0.2 μm) and podoms (small dilations accommodating caveolae, mitochondria, and endoplasmic reticulum). Tp ramifications follow a dichotomic pattern and establish specialized cell-to-cell junctional complexes. TCs, via their Tp, seem to form an interstitial network beneath the mesothelium, covering about two-thirds of the abluminal mesothelial layer. ET has revealed complex junctional structures and tight junctions connecting pleural TCs, and small vesicles at this level in Tp. Thus, pleural TCs share significant similarities with TCs described in other serosae. Whether TCs are a (major) player in mesothelial-cell-induced tissue repair remains to be established. Nevertheless, the extremely long thin Tp and complex junctional structures that they form and the release of vesicles (or exosomes) indicate the participation of TCs in long-distance homo- or heterocellular communication
Generation of multiple gain-guided solitons in a fiber laser
Author name used in this publication: H. Y. TamAuthor name used in this publication: C. Lu2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Gain dispersion for dissipative soliton generation in all-normal-dispersion fiber lasers
Author name used in this publication: C. LuAuthor name used in this publication: H. Y. TamAuthor name used in this publication: P. K. A. Wai2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
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