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71.
Xiujian Chou Jing Wang Zhenyu Zhao Wenping Geng Wendong Zhang Jiwei Zhai 《Journal of Electroceramics》2011,26(1-4):185-190
Ba0.5Sr0.5TiO3-BaMg6Ti6O19 microwave composite ceramics with low dielectric constant and relatively high tunability were fabricated via the solid-state reaction method. The microstructures and microwave dielectric properties of the composite ceramics have been investigated. BaMg6Ti6O19 and Ba0.5Sr0.5TiO3 can be friendly coexistent in the composite material system without obvious chemical reactions. With increasing content of BaMg6Ti6O19 from 10 wt.% to 60 wt.%, the dielectric anomalous peaks of ferroelectric-paraelectric phase transition for the composite ceramics are suppressed and broadened. The dielectric constant can be effectively tailored from 2035 to 129. For composite ceramics with 60 wt.% content of BaMg6Ti6O19, the dielectric loss still keeps around 0.002 and the tunability is 13.4% measured at a dc-applied electric field of 30 kV/cm. The Q value of composite ceramics with 20 wt.% content BaMg6Ti6O19 is 367 and the dielectric constant is cut down to 665 at the microwave band of 1.579 GHz. 相似文献
72.
Shiau‐Shin Cheng Peng‐Yi Huang Mohan Ramesh Hsiu‐Chieh Chang Li‐Ming Chen Chia‐Ming Yeh Chun‐Lin Fung Meng‐Chyi Wu Chung‐Chi Liu Choongik Kim Hong‐Cheu Lin Ming‐Chou Chen Chih‐Wei Chu 《Advanced functional materials》2014,24(14):2057-2063
Solution‐processed small‐molecule bulk heterojunction (BHJ) ambipolar organic thin‐film transistors are fabricated based on a combination of [2‐phenylbenzo[d,d']thieno[3,2‐b;4,5‐b']dithiophene (P‐BTDT) : 2‐(4‐n‐octylphenyl)benzo[d,d ']thieno[3,2‐b;4,5‐b']dithiophene (OP‐BTDT)] and C60. Treating high electrical performance vacuum‐deposited P‐BTDT organic semiconductors with a newly developed solution‐processed organic semiconductor material, OP‐BTDT, in an optimized ratio yields a solution‐processed p‐channel organic semiconductor blend with carrier mobility as high as 0.65 cm2 V?1 s?1. An optimized blending of P‐BTDT:OP‐BTDT with the n‐channel semiconductor, C60, results in a BHJ ambipolar transistor with balanced carrier mobilities for holes and electrons of 0.03 and 0.02 cm2 V?1 s?1, respectively. Furthermore, a complementary‐like inverter composed of two ambipolar thin‐film transistors is demonstrated, which achieves a gain of 115. 相似文献
73.
Yao-Hsin Chou Guo-Jyun Zeng Fang-Jhu Lin Chi-Yuan Chen Han-Chieh Chao 《Mobile Networks and Applications》2014,19(1):121-130
In this paper, we propose a communication protocol called Controlled Bidirectional Quantum Secret Direct Communication (CBQSDC) for mobile networks. In mobile networks, telecom companies assist the agent ensuring both sides could receive the other’s secret messages in the transmission by quantum theory simultaneously. This protocol is based on n-particle GHZ states (Greenberger-Horne-Zeilinger-states) which are transformed to Einstein-Podolsky-Rosen (EPR) pairs by entanglement swapping. GHZ states are used to carry both sides’ messages and entanglement swapping could reduce the number of transmission, so we could decrease the probability of eavesdropping. If any eavesdropper tries to steal dealer’s messages, the lawful participants will perceive it and abort their transmission. 相似文献
74.
75.
利用Gleeble-3500热模拟系统和电子背散射衍射(EBSD)技术对5083铝合金超快速退火组织的演变规律进行了研究,探讨了5083铝合金经过80%冷轧变形后以500 ℃/s加热至450 ℃时,不同保温时间(1~60 s,冷却速度40 ℃/s)对退火组织及力学性能的影响。结果表明,随退火保温时间从1 s延长到60 s,5083铝合金的平均晶粒尺寸由4.94 μm增大到6.44 μm,合金中主要产生了再结晶立方退火织构{001}<100>、旋转立方织构{001}<110>,以及少量的高斯织构{011}<100>和黄铜型织构{011}<211>。当退火保温时间从1 s增加到60 s,整体上合金中的再结晶退火织构先增强再减弱。退火保温时间对5083铝合金的强度影响较小,5083铝合金的屈服强度、抗拉强度没有明显的变化,分别约为170 MPa、326 MPa,而其伸长率由25.63%逐渐增大至30.06%,最后又降低至25.20%。 相似文献
76.
文章以区域调度理论为基础,提出了构建城市公共自行车调度系统进行了构建,并以GSM通信技术、定位系统技术等为技术支撑,从而对系统进行了实现。 相似文献
77.
Chien‐Liang Liu Yung‐Kang Peng Shang‐Wei Chou Wei‐Hsuan Tseng Yu‐Jui Tseng Hsieh‐Chih Chen Jong‐Kai Hsiao Pi‐Tai Chou 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(19):3962-3969
The room‐temperature, aqueous‐phase synthesis of iron‐oxide nanoparticles (IO NPs) with glutathione (GSH) is reported. The simple, one‐step reduction involves GSH as a capping agent and tetrakis(hydroxymethyl)phosphonium chloride (THPC) as the reducing agent; GSH is an anti‐oxidant that is abundant in the human body while THPC is commonly used in the synthesis of noble‐metal clusters. Due to their low magnetization and good water‐dispersibility, the resulting GSH‐IO NPs, which are 3.72 ± 0.12 nm in diameter, exhibit a low r2 relaxivity (8.28 mm ?1s?1) and r2/r1 ratio (2.28)—both of which are critical for T1 contrast agents. This, together with the excellent biocompatibility, makes these NPs an ideal candidate to be a T1 contrast agent. Its capability in cellular imaging is illustrated by the high signal intensity in the T1‐weighted magnetic resonance imaging (MRI) of treated HeLa cells. Surprisingly, the GSH‐IO NPs escape ingestion by the hepatic reticuloendothelial system, enabling strong vascular enhancement at the internal carotid artery and superior sagittal sinus, where detection of the thrombus is critical for diagnosing a stroke. Moreover, serial T1‐ and T2‐weighted time‐dependent MR images are resolved for a rat's kidneys, unveiling detailed cortical‐medullary anatomy and renal physiological functions. The newly developed GSH‐IO NPs thus open a new dimension in efforts towards high‐performance, long‐circulating MRI contrast agents that have biotargeting potential. 相似文献
78.
Multimedia Tools and Applications - Efficient access to broadcasted computer game videos is urgently demanded due to the emergence of live streaming platforms. The popularity of game video... 相似文献
79.
Chun-Chia Chen Huey-Ing Chen I.-Ping Liu Po-Cheng Chou Jian-Kai Liou Yung-Jen Chiou Hao-Yeh Liu Wen-Chau Liu 《International Journal of Hydrogen Energy》2014
A Pd/GaN/AlGaN heterostructure field-effect transistor (HFET)-type hydrogen gas sensor, based on an electrophoretic deposition (EPD) approach, is fabricated and studied. Due to the formation of good Schottky gate contact by an EPD approach, the studied HFET shows improved DC performance including the suppressed gate current and better thermal stabilities on current–voltage (I–V) characteristics. This is mainly attributed to the reduction of interface trap density and improved Pd morphology. The EPD-based Pd morphologies are examined by X-ray diffraction, energy dispersive spectroscopy, Auger electron spectroscopy, scanning electron microscopy, and atomic force microscopy. For the used gate-dimension of 1 μm × 100 μm, an EPD-based HFET shows low gate current of 2.9 nA, maximum drain saturation current of 490 mA/mm, and maximum extrinsic transconductance of 78.9 mS/mm at room temperature. Also, solid thermal stabilities on maximum drain saturation current (−0.46 mA/mm K) and maximum extrinsic transconductance (−0.08 mS/mm K) are found as the temperature is increased from 300 to 600 K. For hydrogen gas sensing application, at 370 K, the maximum hydrogen sensitivity of 600.1 μA/mm ppm H2/air under a 5 ppm H2/air ambiance and fast response time (30 s) and recovery time (47 s) under a 10,000 ppm H2/air ambiance are obtained. The EPD approach also demonstrates advantages of low cost, simple apparatus, easy process, little restriction on the shaped substrate, composited deposition, and adjustable alloy grain size. Therefore, the proposed EPD approach gives the promise for fabricating high-performance HFET devices and hydrogen gas sensors. 相似文献
80.
In this study, we used metal organic chemical vapor deposition to form gallium nitride (GaN) epilayers on c- and a-axis sapphire
substrates and then used the nanoscratch technique and atomic force microscopy (AFM) to determine the nanotribological behavior
and deformation characteristics of the GaN epilayers, respectively. The AFM morphological studies revealed that pile-up phenomena
occurred on both sides of the scratches formed on the GaN epilayers. It is suggested that cracking dominates in the case of
GaN epilayers while ploughing during the process of scratching; the appearances of the scratched surfaces were significantly
different for the GaN epilayers on the c- and a-axis sapphire substrates. In addition, compared to the c-axis substrate, we
obtained higher values of the coefficient of friction (μ) and deeper penetration of the scratches on the GaN a-axis sapphire
sample when we set the ramped force at 4,000 μN. This discrepancy suggests that GaN epilayers grown on c-axis sapphire have
higher shear resistances than those formed on a-axis sapphire. The occurrence of pile-up events indicates that the generation
and motion of individual dislocation, which we measured under the sites of critical brittle transitions of the scratch track,
resulted in ductile and/or brittle properties as a result of the deformed and strain-hardened lattice structure. 相似文献