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排序方式: 共有2380条查询结果,搜索用时 140 毫秒
941.
Choon Ki Ahn 《中国物理 B》2010,19(10):100201-100201
This paper proposes an L2 -L∞ learning law as a new learning method for dynamic neural networks with external disturbance. Based on linear matrix inequality (LMI) formulation, the L2-L∞ learning law is presented to not only guarantee asymptotical stability of dynamic neural networks but also reduce the effect of external disturbance to an L2-L∞ induced norm constraint. It is shown that the design of the L2-L∞ learning law for such neural networks can be achieved by solving LMIs, which can be easily facilitated by using some standard numerical packages. A numerical example is presented to demonstrate the validity of the proposed learning law. 相似文献
942.
Wongi Park Dr. Beatriz Feringán Minyong Yang Seong Ho Ryu Dr. Hyungju Ahn Prof. Dr. Tae Joo Shin Dr. Teresa Sierra Dr. Raquel Giménez Prof. Dr. Dong Ki Yoon 《Chemphyschem》2019,20(6):890-897
Ambipolar organic semiconductors are considered promising for organic electronics because of their interesting electric properties. Many hurdles remain yet to be overcome before they can be used for practical applications, especially because their orientation is hard to control. We demonstrate a method to control the orientation of columnar structures based on a hydrogen (H)-bonded donor-acceptor complex between a star-shaped tris(triazolyl)triazine and triphenylene-containing benzoic acid, using physicochemical nanoconfinement. The molecular configuration and supramolecular columnar assemblies in a one-dimensional porous anodic aluminium oxide (AAO) film were dramatically modulated by controlling the pore-size and by chemical modification of the inner surface of the porous AAO film. In situ experiments using grazing-incidence X-ray diffraction (GIXRD) were carried out to investigate the structural evolution produced at the nanometer scale by varying physicochemical conditions. The resulting highly ordered nanostructures may open a new pathway to effectively control the alignment of liquid crystal ambipolar semiconductors. 相似文献
943.
Armin Darvish Jung Soo Lee Bin Peng Jugal Saharia Ramalingam VenkatKalyana Sundaram Gaurav Goyal Nuwan Bandara Chi Won Ahn Jungsuk Kim Prashanta Dutta Irwin Chaiken Min Jun Kim 《Electrophoresis》2019,40(5):776-783
Enveloped viruses fuse with cells to transfer their genetic materials and infect the host cell. Fusion requires deformation of both viral and cellular membranes. Since the rigidity of viral membrane is a key factor in their infectivity, studying the rigidity of viral particles is of great significance in understating viral infection. In this paper, a nanopore is used as a single molecule sensor to characterize the deformation of pseudo‐type human immunodeficiency virus type 1 at sub‐micron scale. Non‐infective immature viruses were found to be more rigid than infective mature viruses. In addition, the effects of cholesterol and membrane proteins on the mechanical properties of mature viruses were investigated by chemically modifying the membranes. Furthermore, the deformability of single virus particles was analyzed through a recapturing technique, where the same virus was analyzed twice. The findings demonstrate the ability of nanopore resistive pulse sensing to characterize the deformation of a single virus as opposed to average ensemble measurements. 相似文献
944.
Milan K. Sadan Seon-Hwa Choi Hui Hun Kim Changhyeon Kim Gyu-Bong Cho Ki-Won Kim N. S. Reddy Jou-Hyeon Ahn Hyo-Jun Ahn 《Ionics》2018,24(3):753-761
To determine the effect of electrolyte salts on the cycling properties of tin anodes in sodium ion batteries, sodium/tin cells were prepared using eight electrolytes containing NaCF3SO3, NaBF4, NaClO4, and NaPF6 in ethylene carbonate-dimethyl carbonate (EC-DMC) and EC-DMC/fluoroethylene carbonate (FEC) solvents. The first charge capacity and cycling properties strongly depended on the electrolyte salts. Additionally, an appropriately chosen electrolyte salt in combination with the FEC additive improved the cycling properties of the tin electrode. The tin electrode in the presence of the FEC-containing NaPF6-based electrolyte exhibited the best cycling properties. The first charge capacity and charge capacity after the 45th cycle were 220 and 189 mAh g?1 electrode, respectively at a current density of 84.7 mA g?1 electrode. The rate performance is also studied using the optimized electrolyte which reveals the ability of the electrode to perform in high current application. At a high current density of 4235 mA g?1 electrode, the capacity delivered is 24 mAh g?1 electrode. At a current rate of 1694 mA g?1 electrode, at the end of 1400th cycle, capacity is about 45 mAh g?1 electrode. The results of the study clearly indicate that the electrolyte salts critically affect the electrochemical performance of the tin anode in sodium ion batteries. 相似文献
945.
A. D. Panov J. H. Adams Jr. H. S. Ahn G. L. Bashinzhagyan J. W. Watts J. P. Wefel J. Wu O. Ganel T. G. Guzik V. I. Zatsepin I. Isbert K. C. Kim M. Christl E. N. Kouznetsov M. I. Panasyuk E. S. Seo N. V. Sokolskaya J. Chang W. K. H. Schmidt A. R. Fazely 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(5):564-567
The final results of processing the data from the balloon-born experiment ATIC-2 (Antarctica, 2002–2003) for the energy spectra of protons and He, C, O, Ne, Mg, Si, and Fe nuclei, the spectrum of all particles, and the mean logarithm of atomic weight of primary cosmic rays as a function of energy are presented. The final results are based on improvement of the methods used earlier, in particular, considerably increased resolution of the charge spectrum. The preliminary conclusions on the significant difference in the spectra of protons and helium nuclei (the proton spectrum is steeper) and the non-power character of the spectra of protons and heavier nuclei (flattening of carbon spectrum at energies above 10 TeV) are confirmed. A complex structure of the energy dependence of the mean logarithm of atomic weight is found. 相似文献
946.
Dhimiter Bello Brian L. Wardle Namiko Yamamoto Roberto Guzman deVilloria Enrique J. Garcia Anastasios J. Hart Kwangseog Ahn Michael J. Ellenbecker Marilyn Hallock 《Journal of nanoparticle research》2009,11(1):231-249
This study investigated airborne exposures to nanoscale particles and fibers generated during dry and wet abrasive machining
of two three-phase advanced composite systems containing carbon nanotubes (CNTs), micron-diameter continuous fibers (carbon
or alumina), and thermoset polymer matrices. Exposures were evaluated with a suite of complementary instruments, including
real-time particle number concentration and size distribution (0.005–20 μm), electron microscopy, and integrated sampling
for fibers and respirable particulate at the source and breathing zone of the operator. Wet cutting, the usual procedure for
such composites, did not produce exposures significantly different than background whereas dry cutting, without any emissions
controls, provided a worst-case exposure and this article focuses here. Overall particle release levels, peaks in the size
distribution of the particles, and surface area of released particles (including size distribution) were not significantly
different for composites with and without CNTs. The majority of released particle surface area originated from the respirable
(1–10 μm) fraction, whereas the nano fraction contributed ~10% of the surface area. CNTs, either individual or in bundles,
were not observed in extensive electron microscopy of collected samples. The mean number concentration of peaks for dry cutting
was composite dependent and varied over an order of magnitude with highest values for thicker laminates at the source being
>1 × 106 particles cm−3. Concentration of respirable fibers for dry cutting at the source ranged from 2 to 4 fibers cm−3 depending on the composite type. Further investigation is required and underway to determine the effects of various exposure
determinants, such as specimen and tool geometry, on particle release and effectiveness of controls.
相似文献
Dhimiter BelloEmail: |
947.
M. R. Kim S. J. Ahn D.-J. Jang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,52(1-3):75-78
MoO3 clusters-coated TiO2 nanotubes were synthesized wet-chemically and characterized by measuring photoluminescence spectra and kinetic profiles as well as extinction spectra and electron microscope images. TiO2 nanotubes having an average outer diameter of 30 nm and an average thickness of 8 nm are surrounded by MoO3 clusters with an average thickness of 4 nm. The excitation of both the TiO2 cores and the MoO3 shells of the type-II nanocomposites suspended in water yields charge-transferred junction photoluminescence having a long lifetime of 2.3 ns at 460 nm. 相似文献
948.
Dae-Hyeong Kim Jong-Hyun Ahn Hoon-Sik Kim Keon Jae Lee Tae-Ho Kim Chang-Jae Yu Nuzzo R.G. Rogers J.A. 《Electron Device Letters, IEEE》2008,29(1):73-76
CMOS inverters and three-stage ring oscillators were formed on flexible plastic substrates by transfer printing of p-type and n-type single crystalline ribbons of silicon. The gain and the sum of high and low noise margins of the inverters were as high as ~150 and 4.5 V at supply voltages of 5 V, respectively. The frequencies of the ring oscillators reached 2.6 MHz at supply voltages of 10 V. These results, as obtained with devices that have relatively large critical dimensions (i.e., channel lengths in the several micrometer range), taken together with good mechanical bendability, suggest promise for the use of this type of technology for flexible electronic systems. 相似文献
949.
Min Yang Hyung Soo Ahn Tomoyuki Tanikawa Yoshio Honda Masahito Yamaguchi Nobuhiko Sawaki 《Journal of Crystal Growth》2009,311(10):2914-2918
Semi-polar (1 1 2¯ 2) GaN layers were selectively grown by metal organic chemical vapor phase epitaxy on patterned Si (3 1 1) substrates without SiO2 amorphous mask. The (1 1 2¯ 2) GaN layers could be selectively grown only on Si (1 1 1) facets when the stripe mask width was narrower than 1 μm even without SiO2. Inhomogeneous spatial distribution of donor bound exciton (DBE) peak in low-temperature cathodoluminescence (CL) spectra was explained by the difference of growth mode before and after the coalescence of stripes. It was found that the emission intensity related crystal defects is drastically decreased in case of selective growth without SiO2 masks as compared to that obtained with SiO2 masks. 相似文献
950.
Van Tu Nguyen Seongju Ha Dong-Il Yeom Yeong Hwan Ahn Soonil Lee Ji-Yong Park 《Current Applied Physics》2019,19(10):1127-1131
Large-scale growth of mostly monolayer molybdenum disulfide (MoS2) on quartz, sapphire, SiO2/Si, and waveguide substrates is demonstrated by chemical vapor deposition with the same growth parameters. Centimeter-scale areas with large flakes and films of MoS2 on all the growth substrates are observed. The atomic force microscopy and Raman measurements indicate the synthesized MoS2 is monolayer with high quality and uniformity. The MoS2 field effect transistors based on the as-grown MoS2 exhibit carrier mobility of 1–2 cm2V?1s?1 and On/Off ratio of ~104 while showing large photoresponse. Our results provide a simple approach to realize MoS2 on various substrates for electronics and optoelectronics applications. 相似文献