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排序方式: 共有1727条查询结果,搜索用时 312 毫秒
981.
Hye Moon Lee Soon Gil Kim Isao Matsui Toru Iwaki Ferry Iskandar I. Wuled Lenggoro Kikuo Okuyama 《Journal of magnetism and magnetic materials》2007
The deposition monolayers of L10 FePt nanoparticles via an electrospraying method and the magnetic properties of the deposited film were studied. FePt nanoparticles in a size of around 2.5 nm in diameter, prepared by a liquid process, were used as a precursor. The size of the deposited particles can be controlled up to 35 nm by controlling the sprayed droplet size that is formed by adjusting the precursor concentration and the precursor flow rate. The droplets were heated in a tubular furnace at a temperature of up to 900 °C to remove all organic compounds and to transform the FePt particles from disordered face centered cubic to an ordered FCT phase. Finally, the particles were deposited in the form of a monolayer film on a silicon substrate by electrostatic force and characterized by scanning electron microscopy. The monolayer of particles was obtained by the high charge on particles obtained during the electrospraying process. The magnetic properties of the monolayer were investigated by magneto-optic Kerr effect measurements. Coercivity up to 650 Oe for a film consisting of 35 nm L10 FePt nanoparticles was observed after heat treatment at a temperature of 800 °C. 相似文献
982.
Bradley DK Eggert JH Hicks DG Celliers PM Moon SJ Cauble RC Collins GW 《Physical review letters》2004,93(19):195506
Laser generated shock reflectance data show that diamond undergoes a continuous transition from optically absorbing to reflecting between Hugoniot pressures 600
相似文献
983.
Four new diarylheptanoids from the roots of Juglans mandshurica 总被引:10,自引:0,他引:10
Li G Xu ML Choi HG Lee SH Jahng YD Lee CS Moon DC Woo MH Son JK 《Chemical & pharmaceutical bulletin》2003,51(3):262-264
Four new diarylheptanoids (1-4), along with two known tetralones (5, 6), were isolated from the roots of Juglans mandshurica and their structures were elucidated on the basis of spectroscopic studies. 相似文献
984.
Two counterpropagating laser beams were used to significantly stretch soft dielectrics such as cells. The deforming forces act on the surface between the object and the surrounding medium and are considerably higher than the trapping forces on the object. Radiation damage is avoided since a double-beam trap does not require focusing for stable trapping. Ray optics was used to describe the stress profile on the surface of the trapped object. Measuring the total forces and deformations of well-defined elastic objects validated this approach. 相似文献
985.
Francis C. Moon 《Experimental Mechanics》1975,15(5):184-189
The passage of transient electric currents through a gas into a solid occurs in high-voltage switches and in lightning strikes. The experiments reported in this paper were designed to examine the vibration of a cantilevered conductor under electromagnetic forces of the arc and structural currents. Arcs are created at low pressures in a vacuum facility and the induced vibrations of the beam are measured. It is shown that the deflections are proportional to the square of the arc currents. Further, 5-μs photographs of the 2-ms arc, using a Kerr cell, show that the arc is distorted by the magnetic field of the beam currents. A simple analytical model is shown to reproduce the basic results of the experiments. 相似文献
986.
The final state for nonlinear systems with multiple attractors may become unpredictable as a result of homoclinic or heteroclinic bifurcations. The fractal basin boundaries due to such bifurcations for a four-well, two-degree-of-freedom, nonlinear oscillator under sinusoidal forcing have been studied, based on a theory of homoclinic bifurcation inn-dimensional vector space developed by Palmer. Numerical simulation is used as a means of demonstrating the consequences of the system dynamics when the bifurcations occur, and it is shown that the basin boundaries in the configuration space (x, y) become fractal near the critical value of the heteroclinic bifurcations. 相似文献
987.
988.
Jeffrey Luo Huibin Chang Amir A. Bakhtiary Davijani H. Clive Liu Po-Hsiang Wang Robert J. Moon Satish Kumar 《Cellulose (London, England)》2017,24(4):1745-1758
Polyacrylonitrile-co-methacrylic acid (PAN-co-MAA) and cellulose nanocrystal (CNC) composite films were produced with up to 40 wt% CNC loading through the solution casting method. The rheological properties of the solution/suspensions and the structural, optical, thermal, and mechanical properties of the resulting films were investigated. The viscosity of the composite suspensions increased with higher CNC loadings and with longer aging times. PAN-co-MAA/CNC films maintained a similar level of optical transparency even with up to 40 wt% CNC loading. The glass transition temperature (Tg) increased from 92 to 118 °C, and the composites had higher thermal stability below 350 °C compared to both neat PAN-co-MAA and neat CNC. The mechanical properties also increased with higher CNC loadings, elastic modulus increased from 2.2 to 3.7 GPa, tensile strength increased from 75 to 132 MPa, and the storage modulus increased from 3.9 to 10.5 GPa. Using the Kelly and Tyson model the interfacial shear strength between the PAN-co-MAA and CNC was calculated to be 27 MPa. 相似文献
989.
In this paper we establish asymptotic results and a generalized uniform law of the iterated logarithm (LIL) for the increments of a strictly stationary random process, whose results are proved by separating linearly positive quadrant dependent (LPQD) random process and linearly negative quadrant dependent (LNQD) one, respectively. 相似文献
990.
Designing a Highly Active Metal‐Free Oxygen Reduction Catalyst in Membrane Electrode Assemblies for Alkaline Fuel Cells: Effects of Pore Size and Doping‐Site Position 下载免费PDF全文
Seonggyu Lee Myounghoon Choun Youngjin Ye Prof. Dr. Jaeyoung Lee Yeongdong Mun Dr. Eunae Kang Jongkook Hwang Young‐Ho Lee Prof. Dr. Chae‐Ho Shin Prof. Dr. Seung‐Hyeon Moon Prof. Dr. Soo‐Kil Kim Prof. Dr. Eunsung Lee Prof. Dr. Jinwoo Lee 《Angewandte Chemie (International ed. in English)》2015,54(32):9230-9234
To promote the oxygen reduction reaction of metal‐free catalysts, the introduction of porous structure is considered as a desirable approach because the structure can enhance mass transport and host many catalytic active sites. However, most of the previous studies reported only half‐cell characterization; therefore, studies on membrane electrode assembly (MEA) are still insufficient. Furthermore, the effect of doping‐site position in the structure has not been investigated. Here, we report the synthesis of highly active metal‐free catalysts in MEAs by controlling pore size and doping‐site position. Both influence the accessibility of reactants to doping sites, which affects utilization of doping sites and mass‐transport properties. Finally, an N,P‐codoped ordered mesoporous carbon with a large pore size and precisely controlled doping‐site position showed a remarkable on‐set potential and produced 70 % of the maximum power density obtained using Pt/C. 相似文献