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Gaofeng Zheng Zhaojie Yu Mingfeng Zhuang Wen Wei Yang Zhao Jiangyi Zheng Daoheng Sun 《Applied Physics A: Materials Science & Processing》2014,116(1):171-177
This paper studies the whipping deposition behavior of straight charged jets of Near-Field Electrospinning. A micro 3D structure of multi-loop nanofibrous coil was printed on a silicon collector. The whipping motion resulted from Coulomb force caused the charged jet to deposit and form a coiled structure. With the guidance of deposited nanofiber, the charged jet deposited layer by layer to build up a 3D nanofibrous coiled structure with 3–50 loops. The diameter of the coiled structure ranged from 4 to 60 μm. The number of loops decreased with the increase of collector motion speed, due to shorter post-deposition relaxing time. With higher stress inside the charged jet, PEO solution of higher concentration led to fewer loops but larger diameter of the coil. This work provides a promising method to study the control technology of charged jet printing, which may push forward the development of micro 3D inkjet printing technology. 相似文献
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Electronic structure of three-dimensional quantum dots 总被引:1,自引:0,他引:1
T. Vorrath R. Blümel 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,32(2):227-235
We study the electronic structure of three-dimensional quantum dots using the Hartree-Fock approximation. The confining potential
of the electrons in the quantum dot is assumed to be spatially isotropic and harmonic. For up to 40 interacting electrons
the ground-state energies and ground-state wavefunctions are calculated at various interaction strengths. The quadrupole moments
and electron densities in the quantum dot are computed. Hund's rule is confirmed and a shell structure is identified via the addition energies and the quadrupole moments. While most of the shell structure can be understood on the basis of the
unperturbed non-interacting problem, the interplay of an avoided crossing and the Coulomb interaction results in an unexpected
closed shell for 19 electrons.
Received 5 November 2001 / Received in final form 12 November 2002 Published online 1st April 2003
RID="a"
ID="a"e-mail: vorrath@physnet.uni-hamburg.de 相似文献
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The human brain hexacoordinated neuroglobin three-dimensional structure 总被引:11,自引:0,他引:11
Pesce A Dewilde S Nardini M Moens L Ascenzi P Hankeln T Burmester T Bolognesi M 《Micron (Oxford, England : 1993)》2004,35(1-2):63-65
Neuroglobin, mainly expressed in vertebrate brain and retina, is a recently identified member of the globin superfamily. Augmenting O2 supply, neuroglobin promotes survival of neurons upon hypoxic injury, potentially limiting brain damage. In the absence of exogenous ligands, neuroglobin displays a six-coordinated heme. O2 and CO bind to the heme-iron, displacing the endogenous HisE7 heme distal ligand. Hexacoordinated human neuroglobin displays a classical globin fold, adapted to host the reversible bis-histidyl heme complex, and an elongated protein matrix cavity, held to facilitate O2 diffusion to the heme. The structure of neuroglobin suggests that the classical globin fold is endowed with striking adaptability, indicating that hemoglobin and myoglobin are just two examples within a wide and functionally diversified protein homology superfamily. 相似文献
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H. Franke 《Zeitschrift für Physik B Condensed Matter》1982,45(3):247-253
We study the surface behaviour of very large percolation clusters above the critical concentrationp
c by considering the width and the analogue of surface tension of the interface separating the interior of the cluster from the outside region. Our Monte Carlo simulation techniques, which are described in detail, are applied to a quadraticL ×L surface layer on the simple cubic lattice, withL up to 200. They give clearly a rough surface even for the highest concentrationsp. The data forp=1 suggest a logarithmic divergence for the interface width in the thermodynamic limitL. 相似文献
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采用三维全息原子场作用矢量(3D-HoVAIF)对115个酰肼类抗结核病药物进行定量构效关系(QSAR)研究.运用多元线性回归(MLR)和偏最小二乘回归(PLS)建模,同时采用内部及外部双重验证的办法对所得模型稳定性能进行了深入分析和检验.MLR建模和PLS建模的复相关系数(R2cum)、留一法交互校验复相关系数(Q2LOO)以及外部样本校验复相关系数(Q2ext)分别为0.766、0.663、0.748和0.733、0.614、0.715.结果表明,3D-HoVAIF能较好表征抗结核药物分子结构信息,所建QSAR模型具有良好稳定性和预测能力,为抗结核病药物的研发提供一定的理论基础. 相似文献
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Photonic band structure of three-dimensional colloidal crystals with field-induced lattice structure transformation
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By utilizing the electrorheological effect,
three-dimensional colloidal crystals can be produced, whose lattice
structure can be changed from the body-centered-tetragonal lattice
to other lattices under the application of electric fields. This
paper calculates photonic band structures of such crystals with
lattice structure transformation, and demonstrates the existence of
complete band gaps for some intermediate lattices. Thus, it becomes
possible to use the electrorheological effect to achieve photonic
crystals with desired photonic gap properties resulting from tunable
structures. 相似文献
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All known topological insulators are crystallographically related to either the noncentrosymmetric zinc-blende HgTe-type family or to the hexagonal centrosymmetric Bi2Se3 one. Through first-principles calculations, here we show evidence that under a proper uniaxial strain cubic ternary centrosymmetric antiperovskite compounds (M3N)Bi (M=Ca, Sr, and Ba) are three-dimensional topological insulators. This proposed family of materials is chemically inert and the lattice structure is well matched to important semiconductors, which provides a rich platform to easily integrate with electronic devices. 相似文献
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In this paper, a broadband metamaterial absorber is successfully designed by a three-dimensional structure. And the three-dimensional absorber is just obtained by a two-dimensional structure which rotates 90°along x-axis. The simulated results show that the absorption of the three-dimensional metamaterial absorber is much better than the two-dimensional absorber. Moreover, the absorber is polarization-sensitive for the incident electromagnetic waves due to the asymmetry of the structure. Compared with the Y-polarization wave, the proposed absorber can realize broadband absorption with greater than 90% from 355.6 to 737.7 THz for X-polarized wave. Finally, based on the analysis of the electric field and surface current distributions, it can demonstrate that the localized surface plasmons and dipoles resonances will play an important role in the broadband absorption. And we believe that the metamaterial absorber will have many potential applications in emitter and energy harvesting. 相似文献
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Hiroshi Sasaki Atsushi Nakagawa Tomonari Muramatsu Megumi Suganuma Yoriko Sawano Masaki Kojima Keiko Kubota Kenji Takahashi Masaru Tanokura 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2004,80(9):435
Aspergilloglutamic peptidase from Aspergillus niger is a novel pepstatin-insensitive acid endopeptidase distinct from the well-studied aspartic peptidases, and thus is an interesting target for protein structure/function studies. In the present study, we have determined the three-dimensional structure of the enzyme by X-ray crystallography to a 1.4-Å resolution. The results revealed that the enzyme has a unique structure, composed of two seven-stranded anti-parallel β-sheets which form a β-sandwich structure and appear to have a partial two-fold symmetry, suggesting its possible evolution by gene duplication and that the glutamic acid-110 and glutamine-24 in the heavy chain form a catalytic dyad, consistent with our results obtained by site-directed mutagenesis. 相似文献
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基于三维荧光导数光谱的水体有机污染物浓度检测 总被引:3,自引:0,他引:3
提出了应用三维荧光一阶导数光谱检测水体中有机污染物浓度的分析方法。在计算三维荧光导数光谱时,采用Savitzky-Golay多项式拟合微分法对激发、发射光谱分别求导。由于在计算导数光谱时所采用的多项式拟合本身具有平滑功能,因此不需要单独进行平滑处理以去除噪声。针对所构成的四维荧光导数光谱(激发波长,发射波长,激发波长的一阶导数,发射波长的一阶导数),采用偏最小二乘方法建立回归模型。实验结果表明,在对水体中总有机碳的检测中,与常规的三维荧光光谱分析方法相比,文章提出的分析方法可较好地提高分析精度。 相似文献
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A method of moments solution to a three-dimensional whisker structure in a rectangular waveguide is presented. Theoretical results are compared with and verified by corresponding experimental measurements. As a result, it is shown that the orientation of the whisker with typical dimensions is not significant for the impedance tuning. 相似文献
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Kostas Farakos George Koutsoumbas Stavros Sarantakos 《Zeitschrift fur Physik C Particles and Fields》1988,40(3):465-470
The phase diagram of the 3-D U(1) gauge-Higgs models withq=1 andq=2 are derived without freezing the Higgs field length. The models are studied for several values of λ, the Higgs self-coupling. When λ is sufficiently small, new phase transitions appear, due to the radial fluctuations. 相似文献
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Chromaticity-tunable white light emission from organic multiple-quantum-well structure 总被引:1,自引:0,他引:1
Organic multiple quantum wells (MQWs) white light emitting devices are fabricated in which blue fluorescent dye, a trimer of N-anylbenzimidazole (TPBI) and orange fluorescent rubrene doped tris (8-hydroxyquinoline) Aluminum act as quantum-well light emitting layers between triphenyldiamine derivative (TPD) potential barrier layers, and aluminium complex (Alq) act as an electron transporter and green emitter. The injected carriers are confined in different quantum wells and Alq layer. The white light emission comes from a combination of photons generated in different light emitting layers. The Commission Internationale de l' Eclairage (CIE) coordinates of the emitted light are tuned by increasing the number of TPBI wells due to its low fluorescent efficiency compared with rubrene. 相似文献
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Norbert Koch 《固体物理学:研究快报》2012,6(7):277-293
The function and efficiency of most organic electronic and opto‐electronic devices greatly depend on the electronic structure of the interfaces therein. Charge injection from electrical contacts into the organic semiconductor, charge extraction, or exciton dissociation at organic semiconductor heterojunctions are crucial processes that must be optimized for high device efficiency. Consequently, the energy levels at these interfaces must be matched to allow for optimal performance. The key mechanisms that determine the energy level alignment at organic/electrode and organic/organic interfaces are reviewed, and methods to adjust the levels at such interfaces are presented. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献