共查询到20条相似文献,搜索用时 15 毫秒
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The current nano-technology revolution is facing several major challenges: to manufacture nanodevices below 20 nm, to fabricate three-dimensional complex nano-structures, and to heterogeneously integrate multiple functionalities. To tackle these grand challenges, the Center for Scalable and Integrated NAno-Manufacturing (SINAM), a NSF Nanoscale Science and Engineering Center, set its goal to establish a new manufacturing paradigm that integrates an array of new nano-manufacturing technologies, including the plasmonic imaging lithography and ultramolding imprint lithography aiming toward critical resolution of 1–10 nm and the hybrid top-down and bottom-up technologies to achieve massively parallel integration of heterogeneous nanoscale components into higher-order structures and devices. Furthermore, SINAM will develop system engineering strategies to scale-up the nano-manufacturing technologies. SINAMs integrated research and education platform will shed light to a broad range of potential applications in computing, telecommunication, photonics, biotechnology, health care, and national security. 相似文献
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An amino-functionalized montmorillonite (APTMS-MMT) was prepared by the grafting of 3-aminopropyltrimethoxysilane (APTMS) on the surface of MMT via the ultrasonic synthesis process and characterized by a variety of techniques: FT-IR, thermogravimetic analysis (TGA), particles size analysis and ζ-potential measurement. The results showed the size and size distribution of APTMS-MMT particles were decreased, and the ζ-potential of particles was increased obviously via the ultrasonic synthesis process. The particles of 30% APTMS-MMTUS (MMT modified with 30 wt% APTMS with ultrasonic synthesis process) had a z-average diameter of about 500 nm and a polydispersity index of 0.2. The resultant 30% APTMS-MMTUS was dispersed uniformly and stably in water. The poly(acrylic acid) (PAA)/APTMS-MMT multilayer films were grown through layer-by-layer (LBL) deposition of PAA and APTMS-MMT. SEM results indicated that the ultrasonic synthesis of APTMS-MMT increased dispersability of clay sheets at high loadings. The thermal stability and mechanical properties of PAA/APTMS-MMT composites were investigated by TGA and tensile test respectively. The results showed the ultrasonic synthesis of APTMS-MMT enhanced the thermal stability and mechanical properties of PAA/APTMS-MMT composites significantly. PAA/30% APTMS-MMTUS composite displayed 3 times higher strength and 6 times higher Young's modulus when compared with pure PAA polymer. 相似文献
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Analytical solution for multilayer assembly including heating and cooling cycles with laser pulse parameter variation 总被引:1,自引:0,他引:1
Laser heating of surfaces is involved with heating and cooling cycles. Material response to a laser pulse in the heating cycle is rapid while in the cooling cycle it is gradual. In this case, temperature rises rapidly in the heating cycle while temperature decay is gradual in the cooling cycle. Depending on the laser pulse properties (pulse length and intensity), the rise and fall of temperature profiles change in the surface region of the substrate material. In the present study, an analytical solution for laser heating pulse is presented and a closed-form solution for temperature distribution inside the multilayer assembly is obtained. Steel is considered as top layer while copper is situated below steel in the multilayer assembly. It is found that the analytical solution agrees well with the numerical predictions. Temperature rise in steel is higher than copper. This is due to the thickness of steel, which is larger than the absorption depth. In this case, internal energy gain dominates over the heat conduction in the energy transport process. 相似文献
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Ivan I. Stoikov Elena A. Yushkova Anastas A. Bukharaev Dmitry A. Biziaev Svetlana Yu. Selivanovskaya Mariya A. Chursina Igor S. Antipin Alexander I. Konovalov Ilya Zharov 《Journal of Physical Organic Chemistry》2012,25(12):1177-1185
The shape of supramolecular aggregates based on stereoisomers of p‐tert‐butyl thiacalix[4]arenes functionalized with secondary, tertiary amide and hydrazide groups at the lower rim in cone, partial cone and 1,3‐alternate conformations with several metal cations were investigated by atomic force microscopy. The examined p‐tert‐butyl thiacalix[4]arenes form host–guest complexes; dimers, spherics ellipsoids and elongated nanoscale particles depending on the conformation of macrocycles, the nature of the binding centers and the nature of the metal cation. Only associates formed by p‐tert‐butyl thiacalix[4]arenes with morpholide groups at the lower rim in cone conformation with silver cations exhibited a higher antimicrobial activity. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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We show that the basic building blocks of a perfect Penrose pattern (PPT) in two dimensions can be established by adding another
condition to the Penrose’s original edge rules. The implications of this result are discussed in the context of recent papers
by Onada, Jaric, Ronchetti and others concerning growth algorithm for PPT’s. 相似文献
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两个二能级原子与辐射场的量子动力学性质 总被引:7,自引:0,他引:7
用完全量子化方法研究两个二能级原子与腔场相互作用过程中,原子能级占居几率与辐射场的量子动力学性质,讨论了原子间耦合及激光发场对上述性质的影响,揭示了原子耦合与原子-场相互作用之间的联系。 相似文献
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Inert gas ion impacts can be used to manipulate atomic assembly processes during the growth of metallic superlattices but the detailed mechanisms are not well understood. Molecular dynamics simulations are used to investigate the effects of ion incident angle and fluence upon the reassembly and structure of a copper surface partially covered with cobalt asperities. In the low ion energy regime, increasing the ion fluence decreases the cobalt layer surface roughness while gradually leading to an increase in the degree of interfacial mixing. The flattening of asperities occurs by direct (athermal) ion activation of an Ehrlich-Schwoebel mechanism of atom jumping. Intermixing of cobalt surface atoms in an underlying copper layer is found to occur by a knock-on process and the lowest energy barriers for this occur in low-index 〈1 1 0〉 and 〈1 1 2〉 crystal (channeling) directions. The mechanistic insights gained from the study are used to simulate the ion assisted growth of a Cu/Co/Cu multilayer system. Using ion parameters chosen to selectively activate atomic assembly mechanisms that promote flat, unmixed interfacial structures, it is shown that Cu/Co/Cu multilayer structures with high quality, smooth and chemically sharp interfaces can be obtained by using oblique, low energy, moderate fluence ion assistance with an ion mass that is similar to the atomic mass of the metals. 相似文献
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利用磁性液体与聚苯乙烯小球溶液混合得到的复合磁性液体, 研究了聚苯乙烯小球和磁性纳米颗粒在外加磁场作用下的动力学过程. 实验结果表明, 当外加磁场的方向平行于样品平面时, 聚苯乙烯小球在沿着磁场的方向上表现出相互吸引而形成链状结构, 其动力学过程可分为聚苯乙烯小球被反磁化产生相互吸引而形成短链的快过程以及短链间相互吸引形成长链的慢过程; 当外加磁场的方向垂直于样品平面时, 相邻聚苯乙烯小球表现出排斥的相互作用而形成短程有序的二维结构, 当磁场强度增加到一定的阈值时, 聚苯乙烯小球和磁性纳米颗粒形成的团簇会产生相互吸引而组装成复合式的花瓣结构.
关键词:
磁性液体
磁组装
非磁性颗粒 相似文献
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We report an easy, one pot synthesis to prepare ordered CdS nanocrystals with varying inter-particle separation and characterize
the particle separation using x-ray diffraction at low and wide angles. 相似文献
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Silicon-based photonic crystal is a promising material for terahertz (THz) waveguide due to its high refractive index contrast.
In this work, we introduce eye-shaped pillars as the feature building blocks for two-dimensional (2D) photonic crystals. The
simulation study shows that larger TE mode band gaps (PBGs) can be created by the arrangement of dielectric eye-shaped pillars
in air. The reflective spectra demonstrate that there are complex PBGs, where the peak position and intensity can be changed
by varying the parameter e. Moreover, the peak of reflective spectra exhibits an obvious blue shift with the increase of incidence angle of light. When
the vacant space in the structure is filled by polystyrene (PS) microspheres of 2 μm in diameter, the peak intensity of reflective
spectra reduces significantly compared with that without PS microspheres, which suggests that this design can act as a sensor
in the fields of biology, agriculture or medicine. 相似文献
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We consider a combined model of dissipative solitons that are generated due to the balance between gain and loss of energy as well as to the balance between input and output of matter. The system is governed by the generic complex Ginzburg–Landau equation, which is coupled to a common reaction–diffusion (RD) system. Such a composite dynamical system may describe nerve pulses with a significant part of electromagnetic energy involved. We present examples of such composite dissipative solitons and analyse their internal balances between energy and matter generation and dissipation. 相似文献
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René Reichel Jim G. Partridge Alan D.F. Dunbar Simon A. Brown Owen Caughley Ahmad Ayesh 《Journal of nanoparticle research》2006,8(3-4):405-416
The design and operation of a new UHV-compatible atomic cluster deposition system is described. The design is optimised for high cluster fluxes and for the production of cluster-assembled nano-devices. One key feature of the system is a high degree of flexibility, including interchangeable sputtering and inert gas aggregation sources, and two kinds of mass spectrometer, which allow both characterisation of the cluster size distribution and deposition of mass-selected clusters. Another key feature is that clusters are deposited onto electrically contacted lithographically defined devices mounted on an UHV-compatible cryostat cold finger, allowing deposition at room temperature as well as cryogenic and elevated temperatures. In-situ electrical characterisation of cluster-assembled devices can then be performed in the temperature range 1.2--75 K. 相似文献
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