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Author |
Huang, W.; Li, Y.; Niklas, K.J.; Gielis, J.; Ding, Y.; Cao, L.; Shi, P. |
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Title |
A superellipse with deformation and its application in describing the cross-sectional shapes of a square bamboo |
Type |
A1 Journal article |
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Year  |
2020 |
Publication |
Symmetry-Basel |
Abbreviated Journal |
Symmetry-Basel |
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Volume |
12 |
Issue |
12 |
Pages |
2073 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Many cross-sectional shapes of plants have been found to approximate a superellipse rather than an ellipse. Square bamboos, belonging to the genus Chimonobambusa (Poaceae), are a group of plants with round-edged square-like culm cross sections. The initial application of superellipses to model these culm cross sections has focused on Chimonobambusa quadrangularis (Franceschi) Makino. However, there is a need for large scale empirical data to confirm this hypothesis. In this study, approximately 750 cross sections from 30 culms of C. utilis were scanned to obtain cross-sectional boundary coordinates. A superellipse exhibits a centrosymmetry, but in nature the cross sections of culms usually deviate from a standard circle, ellipse, or superellipse because of the influences of the environment and terrain, resulting in different bending and torsion forces during growth. Thus, more natural cross-sectional shapes appear to have the form of a deformed superellipse. The superellipse equation with a deformation parameter (SEDP) was used to fit boundary data. We find that the cross-sectional shapes (including outer and inner rings) of C. utilis can be well described by SEDP. The adjusted root-mean-square error of SEDP is smaller than that of the superellipse equation without a deformation parameter. A major finding is that the cross-sectional shapes can be divided into two types of superellipse curves: hyperellipses and hypoellipses, even for cross sections from the same culm. There are two proportional relationships between ring area and the product of ring length and width for both the outer and inner rings. The proportionality coefficients are significantly different, as a consequence of the two different superellipse types (i.e., hyperellipses and hypoellipses). The difference in the proportionality coefficients between hyperellipses and hypoellipses for outer rings is greater than that for inner rings. This work informs our understanding and quantifying of the longitudinal deformation of plant stems for future studies to assess the influences of the environment on stem development. This work is also informative for understanding the deviation of natural shapes from a strict rotational symmetry. |
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Wos |
000602546300001 |
Publication Date |
2020-12-15 |
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ISSN |
2073-8994 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.7 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 2.7; 2020 IF: 1.457 |
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Call Number |
UA @ admin @ c:irua:174472 |
Serial |
8622 |
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Author |
Cai, H.-bo; Yu, W.; Zhu, S.-ping; Zheng, C.-yang; Cao, L.-hua; Li, B.; Chen, Z.Y.; Bogaerts, A. |
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Title |
Short-pulse laser absorption in very steep plasma density gradients |
Type |
A1 Journal article |
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Year |
2006 |
Publication |
Physics of plasmas |
Abbreviated Journal |
Phys Plasmas |
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Volume |
13 |
Issue |
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Pages |
094504,1-4 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Place of Publication |
Woodbury, N.Y. |
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Wos |
000240877800057 |
Publication Date |
2006-09-15 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1070-664X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.115 |
Times cited |
17 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.115; 2006 IF: 2.258 |
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Call Number |
UA @ lucian @ c:irua:59375 |
Serial |
2995 |
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Author |
Cao, L.-H.; Yu, W.; Xu, H.; Zheng, C.-Y.; Liu, Z.-J.; Li, B.; Bogaerts, A. |
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Title |
Terahertz radiation from oscillating electrons in laser-induced wake fields |
Type |
A1 Journal article |
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Year |
2004 |
Publication |
Physical review : E : statistical physics, plasmas, fluids, and related interdisciplinary topics |
Abbreviated Journal |
Phys Rev E |
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Volume |
70 |
Issue |
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Pages |
046408,1-7 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Strong terahertz (1THz=1012Hz) radiation can be generated by the electron oscillation in fs-laser-induced wake fields. The interaction of a fs-laser pulse with a low-density plasma layer is studied in detail using numerical simulations. The spatial distribution and temporal evolution of terahertz electron current developed in a low-density plasma layer are presented, which enables us to calculate the intensity distribution of THz radiation. It is shown that laser and plasma parameters, such as laser intensity, pulse width, and background plasma density, are of key importance to the process. The optimum condition for wake-field excitation and terahertz emission is discussed upon the simulation results. Radiation peaked at 6.4 THz, with 900 fs duration and 9% bandwidth, can be generated in a plasma of density 5×1017cm−3. It turns out that the maximum radiation intensity scales as n03a04 when wake field is resonantly excited, where n0 and a0 are, respectively, the plasma density and the normalized field amplitude of the laser pulse. |
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Place of Publication |
Lancaster, Pa |
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Wos |
000225689600086 |
Publication Date |
2004-10-14 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1539-3755;1550-2376; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.366 |
Times cited |
9 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.366; 2004 IF: NA |
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Call Number |
UA @ lucian @ c:irua:49818 |
Serial |
3509 |
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Author |
Yu, M.Y.; Yu, W.; Chen, Z.Y.; Zhang, J.; Yin, Y.; Cao, L.H.; Lu, P.X.; Xu, Z.Z. |
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Title |
Electron acceleration by an intense short-pulse laser in underdense plasma |
Type |
A1 Journal article |
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Year |
2003 |
Publication |
Physics of plasmas |
Abbreviated Journal |
Phys Plasmas |
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Volume |
10 |
Issue |
6 |
Pages |
2468-2474 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Electron acceleration from the interaction of an intense short-pulse laser with low density plasma is considered. The relation between direct electron acceleration within the laser pulse and that in the wake is investigated analytically. The magnitude and location of the ponderomotive-force-caused charge separation field with respect to that of the pulse determine the relative effectiveness of the two acceleration mechanisms. It is shown that there is an optimum condition for acceleration in the wake. Electron acceleration within the pulse dominates as the pulse becomes sufficiently short, and the latter directly drives and even traps the electrons. The latter can reach ultrahigh energies and can be extracted by impinging the pulse on a solid target. (C) 2003 American Institute of Physics. |
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Place of Publication |
Woodbury, N.Y. |
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Wos |
000183316500031 |
Publication Date |
2003-05-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1070-664X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.115 |
Times cited |
41 |
Open Access |
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Notes |
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Approved |
Most recent IF: 2.115; 2003 IF: 2.146 |
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Call Number |
UA @ lucian @ c:irua:103293 |
Serial |
904 |
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