33 results on '"Huang, Cheng-Liang"'
Search Results
2. A Nonflammable High‐Voltage 4.7 V Anode‐Free Lithium Battery.
- Author
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Liang, Peng, Sun, Hao, Huang, Cheng‐Liang, Zhu, Guanzhou, Tai, Hung‐Chun, Li, Jiachen, Wang, Feifei, Wang, Yan, Huang, Chen‐Jui, Jiang, Shi‐Kai, Lin, Meng‐Chang, Li, Yuan‐Yao, Hwang, Bing‐Joe, Wang, Chang‐An, and Dai, Hongjie
- Published
- 2022
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3. Rapid detection of perfluorinated sulfonic acids through preconcentration by bubble bursting and surface‐assisted laser desorption/ionization.
- Author
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Lee, Chuping, Yang, Tzu‐Ling, Yao, Yu‐Zhen, Li, Jian‐You, and Huang, Cheng‐Liang
- Subjects
SULFONIC acids ,MATRIX-assisted laser desorption-ionization ,DRINKING water ,DESORPTION ,LASERS ,MASS spectrometry ,PERFLUOROOCTANE sulfonate ,CHEMICAL preconcentration - Abstract
We developed a preconcentration method in which aerosol droplets containing enriched perfluorinated sulfonic acids (PFSs) are generated through bubble bursting and collected. The droplets were subjected to PFS analysis of perfluorohexane sulfonic acid (PFHxS) and perfluorooctanesulfonic acid (PFOS) through surface‐assisted laser desorption/ionization‐time‐of‐flight mass spectrometry; silver nanoplates (AgNPts) were assisting materials. The method was highly efficient, with an approximately three‐order magnitude enhancement (5 × 10−13 to 1 × 10−11 M). Ultralow PFS concentrations (0.5 ng/L of PFOS; 0.4 ng/L of PFHxS) were detected in preconcentrated tap water containing PFSs. Our method has potential for rapid real‐world PFS detection in water. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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4. High‐Safety and High‐Energy‐Density Lithium Metal Batteries in a Novel Ionic‐Liquid Electrolyte.
- Author
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Sun, Hao, Zhu, Guanzhou, Zhu, Yuanmin, Lin, Meng‐Chang, Chen, Hui, Li, Yuan‐Yao, Hung, Wei Hsuan, Zhou, Bo, Wang, Xi, Bai, Yunxiang, Gu, Meng, Huang, Cheng‐Liang, Tai, Hung‐Chun, Xu, Xintong, Angell, Michael, Shyue, Jing‐Jong, and Dai, Hongjie
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- 2020
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5. Microwave dielectric properties of Li2M2(MoO4)3 (M = Co, Ni) for LTCC applications.
- Author
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Huang, Cheng‐Liang, Liou, Jie‐Ning, Tsai, Meng‐Hung, and Huang, Wen‐Chiao
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DIELECTRIC materials ,ELECTRONIC ceramics ,MICROWAVES ,RAMAN spectra ,LATTICE constants - Abstract
Two low‐firing Li2M2(MoO4)3 (M = Co, Ni) dielectrics were prepared, and their microwave dielectric properties were investigated. The XRD patterns indicated both samples crystallized in an orthorhombic structure with different space groups. The microstructures, lattice parameters, and Raman spectra of these ceramics were also systematically studied. The microwave dielectric properties were obtained with εr ~ 9.1, Q × f ~ 34 000 GHz and τf ~ −72 ppm/°C for Li2Co2(MoO4)3 at 840°C, εr ~ 9.6, Q × f ~ 28 000 GHz and τf ~ −71 ppm/°C for Li2Ni2(MoO4)3 at 660°C. With 0.05 mol% Zn substitution, excellent microwave dielectric properties (εr ~ 10.9, Q × f ~ 56 000 GHz and τf ~ −62 ppm/°C) can be obtained for Li2(Ni0.95Zn0.05)2(MoO4)3 at 660°C, indicating a very promising dielectric for LTCC or ULTCC applications at high frequencies. [ABSTRACT FROM AUTHOR]
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- 2020
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6. Conference report—A report from the 5th International Taiwan Symposium on Raman Spectroscopy (TISRS 2017) and Taiwan Association of Raman Spectroscopy (TARS) Summer Camp.
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Huang, Cheng‐Liang, Huang, Chia‐Chi, and Chen, Wenlung
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RAMAN spectroscopy , *RAMAN scattering , *BIOLOGY , *MATERIALS science , *SERS spectroscopy , *CONFERENCES & conventions - Abstract
Abstract: The 5th International Taiwan Symposium on Raman Spectroscopy (TISRS 2017) and Taiwan Association of Raman Spectroscopy (TARS) Summer Camp were held from June 27th to 30th at National Chiayi University in Taiwan. Four plenary speakers and 14 invited speakers, from France, Hong Kong, India, Italy, Japan, New Zealand, Taiwan, and United States, presented their research findings in TISRS in front of an audience of more than 200 participants from 12 countries. Thirty‐seven posters in biology and material sciences were exhibited at the symposium. Following TISRS, five experts delivered lectures to students in the summer camp. The mission of this congress was to promote continuous developments and applications of Raman spectroscopy, with a focus this year on surface‐enhanced Raman scattering (SERS), tip‐enhanced Raman spectroscopy (TERS), imaging methods, and their applications to molecular, biological, and nanomaterial sciences. This meeting also served as a platform for junior researchers to exhibit their recent studies. In this report, we highlight novel findings and perspectives in Raman spectroscopy that emerged in this symposium. The topics of lecture given in the summer camp are listed. [ABSTRACT FROM AUTHOR]
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- 2018
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7. Sol-gel derived TiNb2O7 dielectric thin films for transparent electronic applications.
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Chang, Ming‐Chuan, Huang, Chieh‐Szu, Ho, Yi‐Da, and Huang, Cheng‐Liang
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TITANIUM compounds ,SOL-gel processes ,DIELECTRIC thin films ,TRANSPARENT electronics ,ANNEALING of metals ,GLASS transition temperature - Abstract
To reduce power consumption of transparent oxide-semiconductor thin film transistors, a gate dielectric material with high dielectric constant and low leakage current density is favorable. According to previous study, the bulk TiNb
2 O7 with outstanding dielectric properties may have an interest in its thin-film form. The optical, chemical states and surface morphology of sol-gel derived TiNb2 O7 (TNO) thin films are investigated the effect of postannealing temperature lower than 500°C, which is crucial to the glass transition temperature. All films possess a transmittance near 80% in the visible region. The existence of non-lattice oxygen in the TNO film is proposed. The peak area ratio of non-lattice oxygen plays an important role in the control of leakage current density of MIM capacitors. Also, the capacitance density and dissipation factor were affected by the indium tin oxide (ITO) sheet resistance at high frequencies. The sample after postannealing at 300°C and electrode-annealing at 150°C possesses a high dielectric constant (>30 at 1 MHz) and a low leakage current density (<1 × 10-6 A/cm² at 1 V), which makes it a very promising gate dielectric material for transparent oxide-semiconductor thin film transistors. [ABSTRACT FROM AUTHOR]- Published
- 2018
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8. One-Pot Synthesis of Icosahedral Silver Nanoparticles by Using a Photoassisted Tartrate Reduction Method under UV Light with a Wavelength of 310 nm.
- Author
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Xie, Zhi‐Xuan, Tzeng, Wei‐Che, and Huang, Cheng‐Liang
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- 2016
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9. Influence of Temperature on the Formation of Silver Nanoparticles by using a Seed-Free Photochemical Method under Sodium-Lamp Irradiation.
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Kuo, Yen‐Ling, Juang, Tzong‐Yuan, Chang, Shi‐Hise, Tsai, Chin‐Ming, Lai, Yen‐Shang, Yang, Li‐Chen, and Huang, Cheng‐Liang
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- 2015
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10. The Effects of Annealing Atmosphere on the Electrical Properties of MgNb2O6/ITO Heterostructures.
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Ho, Yi‐Da, Chen, Kung‐Rong, Yu, Pei‐Ching, Huang, Cheng‐Liang, and Ihlefeld, J.
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ANNEALING of metals ,ELECTRIC properties of metals ,HETEROSTRUCTURES ,SOL-gel processes ,OPTOELECTRONICS ,METALLIC thin films - Abstract
The effects of annealing atmosphere ( N
2 , air and O2 ) on the electrical properties of sol-gel-derived MgNb2 O6 / ITO heterostructures are discussed in this work. All samples exhibited the amorphous phase and were highly transparent. The percentage of Nb4+ content increased when the films were annealed in the oxygen-deficient conditions, which could lead to semiconducting films. In addition, the results show that the electrical properties of sol-gel-derived MgNb2 O6 thin films could be tuned based on the annealing atmosphere. Moreover, the conduction mechanisms of MgNb2 O6 / ITO heterostructures are also discussed in this study. The results show that MgNb2 O6 thin films have potential for use in multifunctional optoelectronic applications, due to their flexible electrical properties and good transparency. [ABSTRACT FROM AUTHOR]- Published
- 2015
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11. Resistive Switching Behaviors of Sol-Gel-Derived MgNb2O6 Thin Films on ITO/glass Substrate.
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Ho, Yi‐Da, Chen, Kung‐Rong, Huang, Cheng‐Liang, and Varela, J.
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MAGNESIUM compounds ,INDIUM tin oxide ,GLASS structure ,THIN films ,SOL-gel processes ,ANNEALING of metals - Abstract
In this study, transparent amorphous MgNb
2 O6 ( MNO) films were fabricated via the sol-gel method to form an Al/ MNO/indium tin oxide/glass structure. The resistive switching ( RS) behavior of the devices was investigated. From the DC voltage sweep test, the air-annealed MNO samples exhibited stable and reproducible bipolar resistive switching ( BRS) behavior; however, the samples annealed in an O2 -rich environment showed no RS property. These results suggest that the RS behavior of the MNO memory devices is highly related to the oxygen vacancy concentration and distribution within the MNO films. In addition, forming-free unipolar resistive switching ( URS) behavior was observed when the MNO films were annealed under an N2 H2 atmosphere. In order to determine the origin of the BRS and URS behaviors, cross-sectional high-resolution transmission electron microscopy images of the MNO samples were acquired. The RS behavior of the MNO films can be ascribed to the release and recombination of electrons and oxygen vacancies. [ABSTRACT FROM AUTHOR]- Published
- 2014
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12. Thermal Reaction of Cristobalite in Nano- SiO2/α- Al2 O3 Powder Systems for Mullite Synthesis.
- Author
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Yu, Pei ‐ Ching, Tsai, Yung ‐ Wei, Yen, Fu ‐ Su, Huang, Cheng ‐ Liang, and Wei, W. ‐ C.
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SILICA ,THERMAL properties of metals ,CRISTOBALITE ,MULLITE synthesis ,METAL powders ,HEAT treatment of metals - Abstract
Nanoscaled cristobalite and α- Al
2 O3 powders were used as the starting materials for synthesizing mullite by solid-state reaction. The thermal reaction of the cristobalite with α- Al2 O3 during the thermal treatment was examined. Cristobalite powder with a D50 value of 430 nm was adopted to mix with α- Al2 O3 powders with a D50 values of 230, 310, and 400 nm in a stoichiometric composition of 3 Al2 O3 ∙2 SiO2 (71.8 wt% α- Al2 O3 and 28.2 wt% SiO2 ). Samples for thermal reaction were prepared using uniaxial pressed from the three mixtures that showed various particle number ratios of SiO2 / Al2 O3 due to the different particle sizes of α- Al2 O3. Examinations were performed by differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy techniques. The results showed that cristobalite particles amorphized during the thermal treatment, and then reacted with the α- Al2 O3 particle to form mullite via nucleation and growth. The amorphization temperature can be reduced by using finer-sized α- Al2 O3 powders, thus leading to a lower temperature for mullite formation. Mullite crystals with a multidomain structure were observed in the α- Al2 O3 particle matrixes. The crystal orientation of the mullite was controlled by the α- Al2 O3 matrix, that is, [001] α- Al2 O3 → [001] mullite. These results indicate that the amorphization of cristobalite may trigger the reaction of SiO2 with α- Al2 O3 , initiating the nucleation of mullite. The α- Al2 O3 particles act as the hosts for mullite formation and determine the size of the mullite particles. [ABSTRACT FROM AUTHOR]- Published
- 2014
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13. Sol-Gel-Derived Amorphous- MgNb2 O6 Thin Films for Transparent Microelectronics.
- Author
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Ho, Yi ‐ Da, Chen, Kung ‐ Rong, Huang, Cheng ‐ Liang, and Kuscer, D.
- Subjects
THIN film research ,MICROELECTRONICS research ,SOL-gel processes ,AMORPHOUS substances ,CERAMICS - Abstract
In this work, transparent amorphous- MgNb
2 O6 thin films were fabricated on ITO/glass substrates using the sol-gel method. The change in the chemical states, as well as the optical and dielectric properties of MgNb2 O6 films at various annealing temperatures is investigated. In this study, MgNb2 O6 films exhibited the amorphous phase when the annealing temperature was below 600°C. From X-ray photoelectron spectroscopy, the major parts of the films' chemical states can be indexed as Mg2+ , Nb5+ , Nb4+ , and O2− . Furthermore, the Nb4+ element can be reduced at higher annealing temperatures. The average transmission percentage in the visible range (λ = 400-800 nm) is over 80% for all MgNb2 O6 / ITO/glass samples, whereas the optical band gap ( Eg ) for all samples is estimated at ~4 eV. In addition, the dielectric constant was calculated to be higher than 20 under a 1 MHz AC electric field, with a leakage current density below 2 × 10−7 A/cm2 at 1 V. In this study, the fabrication procedure and experiment results of MgNb2 O6 films are introduced for transparent microelectronics. [ABSTRACT FROM AUTHOR]- Published
- 2013
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14. Strong Near-Infrared Photoluminescence Emission of (003)-Oriented MgTiO3 Thin Films.
- Author
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Ho, Yi ‐ Da, Huang, Cheng ‐ Liang, and Graeve, O.
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NEAR infrared spectroscopy , *PHOTOLUMINESCENCE , *TITANIUM oxides , *THIN films , *ILMENITE , *PARTICLE size distribution , *SPUTTERING (Physics) - Abstract
In this study, ilmenite- MgTiO3 films were sputtered on p-type Si(111) substrates and the extrinsic effects, such as grain size, crystallinity, and orientation of photoluminescence ( PL) properties of the films are discussed. To reduce the effect of oxygen vacancies (act as shallow defects) on PL emissions in the films, oxygen ( O2) was introduced as the sputtering gas and the excitation light source (λ = 532 nm) which has a corresponding energy ( hν = 2.33 eV) below the shallow defect states was used. In this study, intense near-infrared ( NIR) PL emission centered at 810.1 nm at room temperature can be observed when the MgTiO3 thin films exhibit the preferred (003)-orientation and accompanied by the presence of hexagon-shaped grains. In this study, the experiment results reveal that the NIR emission intensity of MgTiO3 films highly depend on crystal orientation and/or grain morphology. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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15. Miniaturization of ring resonator bandpass filters using dielectric ceramic substrates.
- Author
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Huang, ChENg ‐ Liang, Yang, WEN ‐ Ruei, and Huang, SEN ‐ Hung
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MINIATURE electronic equipment , *BANDPASS filters , *MICROWAVE communication systems , *PERMITTIVITY , *DIELECTRICS , *CERAMIC materials , *ELECTROMAGNETISM , *ELECTRIC resonators , *ELECTRIC impedance - Abstract
A compact bandpass filter is designed using stepped impedance ring resonators with zero-degree feed structure.This compact bandpass filters using FR4 and high-permittivity ceramic substrates (with respective dielectric constants of 4.5 and 13.46) are investigated. Using high Q, high permittivity dielectric ceramic materials as substrates, the filters demonstrate high selectivity, compact size, and can be applied in several microwave communication systems. An electromagnetic simulator is used to design the ring resonators, and to calculate the coupling coefficient of the basic coupling strictures. A precise planar bandpass filter with ceramic substrates has been fabricated using the screen printing technique. The responses of bandpass filters using FR4 (εr = 4.5, tan δ = 0.015) and Mg4Nb2O9 with 0.75 wt% Fe2O3 (εr = 13.46, tan δ = 0.00004) ceramic substrates are designed at a center frequency of 2.4 GHz with bandwidth of about 9%. The compact size, low-loss, and performance of the filter are demonstrated in this article. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:660-663, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27346 [ABSTRACT FROM AUTHOR]
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- 2013
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16. Two-poles compact microstrip bandpass filter with sharp transition bands using high permittivity substrate.
- Author
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Yang, Wen-Ruei and Huang, Cheng-Liang
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MICROSTRIP antennas , *BANDPASS filters , *PERMITTIVITY , *MINIATURE electronic equipment , *CERAMIC materials , *DIELECTRICS , *MICROWAVE optics - Abstract
This article describes the two-pole microstrip band-pass filters using miniaturized center-stubbed open stubs and tapped-line input/output ports. The two-poles bandpass filters by using FR4 and high-permittivity ceramic substrates (with respective dielectric constants of 4.5 and 31.55) are investigated. Microwave dielectric ceramics with high permittivity are commonly applied in several microwave communication components. The advantage of using high permittivity ceramic substrates is to reduce the sizes and increase the performance of microstrip bandpass filters. The responses of the filters using FR4 (εr = 4.5, tan δ = 0.015) and Nd(Zn1/2Ti1/2)O3 (εr = 31.55, tan δ= 0.00005) ceramic substrates are designed at a center frequency of 2 GHz. The compact size, low-loss, sharp response, and performance of the filter are presented in this article. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1683-1686, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26889 [ABSTRACT FROM AUTHOR]
- Published
- 2012
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17. Microwave Dielectric Properties of (1 − x)( Mg0.95Ni0.05) TiO3- x( Ca0.8Sr0.2) TiO3 Ceramic System With Near-Zero Temperature Coefficient.
- Author
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Shen, Chun-Hsu, Huang, Cheng-Liang, Chen, Wei-Ting, and Pan, Chung-Long
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CERAMICS , *DIELECTRICS , *SCANNING electron microscopy , *X-rays , *MICROSTRUCTURE , *ILMENITE , *CRYSTAL structure - Abstract
The microwave dielectric properties of the (1 − x)( Mg0.95Ni0.05) TiO3- x( Ca0.8Sr0.2) TiO3 ceramic system prepared by mixed oxide route have been investigated. The crystal structures and the microstructures of the ceramics were characterized by means X-ray and scanning electron microscopy. The microwave dielectric properties are strongly related to the density and matrix of the specimen. Combination of ( Mg0.95Ni0.05) TiO3 (ilmenite-type structure) and ( Ca0.8Sr0.2) TiO3 (perovskite-structured) forms a two-phase system and leads to a near-zero temperature coefficient (τf). With increasing x, the quality factor ( Q × f) decreased and dielectric constant (εr) increased. A new microwave dielectric material 0.95( Mg0.95Ni0.05) TiO3-0.05( Ca0.8Sr0.2) TiO3, possessing excellent microwave dielectric properties with a dielectric constant (εr) of 21.68, a quality factor ( Q × f) of 94,000 (GHz) and a temperature coefficient (τf) of approximately −5.2 ppm/°C at 1275°C for 4 h, is proposed as a suitable candidate material for microwave applications requiring low dielectric loss. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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18. High Q Microwave Dielectric Ceramics in the Li2( Zn1− x A x) Ti3O8 ( A = Mg, Co; x = 0.02-0.1) System.
- Author
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Huang, Cheng-Liang, Su, Chia-Hui, Chang, Chung-Min, and Leite, E.
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SOLID state chemistry , *SINTERING , *MICROWAVES , *X-ray diffraction , *DIELECTRICS , *CERAMIC materials - Abstract
Using a conventional solid-state reaction, followed by sintering at 1080°C-1200°C Li2( Zn1− x A x) Ti3O8 ( A = Mg, Co and x = 0.02-0.1) ceramic system with >96% density were prepared. The XRD patterns of the sintered samples revealed single-phase formation with a cubic crystal symmetry. The molecular volume shows good linear relationship with x value. The microwave dielectric properties of Li2( Zn1− x A x) Ti3O8 ceramics exhibited a significant dependence on the x value and to some extent on the morphology of the specimens. The Li2(Zn0.94Mg0.06)Ti3O8 ceramics possess εr = 26.1, Q × f = 150 000 GHz, and τ f = −13.9 ppm/°C, and Li2(Zn0.92Co0.08)Ti3O8 ceramics show εr = 24.7, Q × f = 140 000 GHz, and τ f = −13.4 ppm/°C, respectively. It indicates a substantial increase in the Q × f in comparison with that of pure Li2ZnTi3O8. The microwave dielectric properties of these partially substituted ceramics are reported for the first time. [ABSTRACT FROM AUTHOR]
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- 2011
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19. Time-Dependent Surface Plasmon Resonance Spectroscopy of Silver Nanoprisms in the Presence of Halide Ions.
- Author
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Hsu, Ming-Sheng, Cao, Yi-Wei, Wang, Hsuang-Wen, Pan, Ya-Sin, Lee, Bo-Hong, and Huang, Cheng-Liang
- Published
- 2010
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20. Microwave Dielectric Properties of (Mg0.95Ni0.05)TiO3–SrTiO3 Ceramics with a Near-Zero Temperature Coefficient of Resonant Frequency.
- Author
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Shen, Chun-Hsu and Huang, Cheng-Liang
- Subjects
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DIELECTRICS , *CERAMICS , *MICROWAVES , *ALUMINUM oxide , *SINTERING - Abstract
The microwave dielectric properties of a (1− x)(Mg0.95Ni0.05)TiO3– xSrTiO3 ceramics system were investigated. The system was prepared using a conventional solid-state ceramic method. To produce a temperature-stable material, SrTiO3 was added, which led to a near-zero temperature variation in resonant frequency. The variation in microwave dielectric properties of the (1− x)(Mg0.95Ni0.05)TiO3– xSrTiO3 ceramics system significantly depends on the amount of SrTiO3 present. As x was varied from 0.01 to 0.1, the microwave Q× f value decreased from 105,000 to 31,000 GHz and the dielectric constant (ℇr) increased from 18.74 to 26.5. A microwave dielectric material with a dielectric constant (ℇr) of 21, a Q× f value of 73,000 GHz, and a τf value of 1 ppm/°C were obtained from the compound 0.96(Mg0.95Ni0.05)TiO3–0.04SrTiO3 sintered at 1300°C for 4 h. To verify the performance of the 0.96(Mg0.95Ni0.05)TiO3–0.04SrTiO3 ceramics, a band-pass filter with traditional hairpin resonators was designed and simulated on different dielectric materials [such as FR4, alumina, and 0.96(Mg0.95Ni0.05)TiO3–0.04SrTiO3]. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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21. Low-Loss Microwave Dielectric Ceramics Using (Mg1− xMn x)2TiO4 ( x=0.02–0.1) Solid Solution.
- Author
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Huang, Cheng-Liang and Chen, Jhih-Yong
- Subjects
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CERAMICS , *COMPOSITE materials , *DIELECTRIC resonators , *SOLID solutions , *MICROWAVE devices , *OXIDES , *X-ray diffraction , *LATTICE dynamics , *ILMENITE - Abstract
Composite ceramics in a solid solution of (Mg1− x Mn x)2TiO4 ( x=0.02–0.1) have been prepared by the mixed oxide route. Formation of the solid solution was confirmed by the X-ray diffraction, the EDX analysis, and the measured lattice parameters, which varied linearly from Mg2TiO4 ( a= b= c=8.4410 Å) to (Mg0.9 Mn0.1)2TiO4 ( a= b= c=8.4445 Å). The XRD analysis also confirmed the co-existence of a cubic-structured (Mg1− xMn x)2TiO4 and an ilmenite-structured second phase (Mg1− xMn x)TiO3. The composition expected to have a maximum Q× f (276 200 GHz at 10.5 GHz) is (Mg0.95Mn0.05)2TiO4 with ℇr∼15.69 and τf∼−52.6 ppm/°C. The existence of the second phase, however, would lead to no significant variation in the dielectric properties of the specimen because it possesses compatible properties compared with that of the main phase. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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22. New manganese catalyzed regiocontrolled synthesis of poly(2,5-dialkyl-1,4-phenylene oxide)s.
- Author
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Lin, Kun-Yu, Su, Chia-Teh, Wang, Ling-Jiun, Huang, Cheng-Liang, and Liang, Mong
- Subjects
MANGANESE compounds ,POLYMERIZATION ,OXIDATIVE coupling ,NUCLEAR magnetic resonance spectroscopy ,THERMOGRAVIMETRY - Abstract
The article presents a study to provide a convenient method for regiocontrolled synthesis of poly(2,5-dialkyl-1,4-phenylene oxide)s using manganese benziloxime complex and dibutylamine as catalysts for oxidative coupling polymerization. It conducted the polymerizations in toluene and studied the structures, properties of the catalyst and polymers. It used nuclear magnetic resonance spectroscopy (NMR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) among others.
- Published
- 2009
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23. Microstrip-fed monopole dumbbell-shaped antenna for UWB application.
- Author
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Tseng, Ching-Fang and Huang, Cheng-Liang
- Subjects
- *
MONOPOLE antennas , *STRIP transmission lines , *MICROSTRIP antennas , *ULTRA-wideband antennas , *BANDWIDTHS , *RADIATION - Abstract
The monopole dumbbell-shaped antenna fed by a 50 Ω microstrip line for ultrawideband (UWB) application is studied. By tuning the dumbbell-shaped radiator and height of the feed gap (D), the monopole antenna has a 2:1 VSWR (return loss < 10 dB) from 2.89 to more than 15 GHz. The bandwidth covered 3.1–10.6 GHz, which has approved by the Federal Communications Commission as a commercial UWB band. Moreover, the antenna features near omnidirectional characteristics in the operation range and good radiation efficiency. The UWB, monopole characteristics of the antenna are confirmed experimentally. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1470–1473, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22404 [ABSTRACT FROM AUTHOR]
- Published
- 2007
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24. Wideband microstrip-fed planar monopole antenna.
- Author
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Tseng, Ching-Fang and Huang, Cheng-Liang
- Subjects
- *
MONOPOLE antennas , *STRIP transmission lines , *MICROSTRIP antennas , *TELECOMMUNICATION systems , *GLOBAL Positioning System - Abstract
The design of a multiband planar monopole antenna with a RF/battery shielding metal case is described. The prototype of the proposed antenna with 0.8 mm in height and 50 mm in length has been fabricated. The proposed antenna exhibits sufficient bandwidth of 915 MHz (1525–2440 MHz) with a voltage standing wave ratio (VSWR) lower than 2:1, which covers global positioning system (1575.42 MHz), digital communication system (1710–1880 MHz), personal communication service (1850–1990 MHz), universal mobile telecommunications system (1920–2170 MHz), and International Mobile Telecommunications-2000 (1900–2025 MHz) bands. At the upper band, the measured impedance bandwidth (2:1 VSWR) of the designed antenna is about 770 (4310–5080 MHz) MHz. This antenna could be applicable for the mobile communication systems. Details of the proposed antenna design and the experimental results are presented and discussed. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1377–1383, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22458 [ABSTRACT FROM AUTHOR]
- Published
- 2007
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25. Microwave Dielectric Properties of Sintered Alumina Using Nano-Scaled Powders of α Alumina and TiO2.
- Author
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Huang, Cheng-Liang, Wang, Jun-Jie, and Huang, Chi-Yuen
- Subjects
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ALUMINUM oxide , *SINTERING , *DIELECTRICS , *MICROWAVES , *NANOSTRUCTURED materials , *POWDERS , *TITANIUM dioxide - Abstract
The microstructure and the microwave dielectric properties of nano-scaled α alumina (α-Al2O3) ceramics with various added amounts of nano-scaled TiO2 have been investigated. The sintering temperature of nano-scaled α alumina can be effectively lowered by increasing the TiO2 content. The Q× f values of nano-scaled α alumina could be tremendously boosted by adding an appropriate amount of TiO2. However, introducing excessive TiO2 into the alumina ceramics would instead lead to a decrease in the Q× f values. The phases of TiO2 and Al2TiO5 co-existed at 1350°C, and the maximum Q× f value appeared right after the eradication of TiO2 phase at 1400°C. Consequently, increasing the TiO2 content to 0.5 wt% yielded a Q× f value of 680 000 GHz (measured at 14 GHz) for nano-scaled α alumina prepared at 1400°C for duration of 4 h. In addition, a very low loss tangent (tan δ) of 2 × 10−5 was also obtained at 14 GHz. The τ f value is strongly correlated to the compositions and can be controlled through the existing phases. In fact, τ f could be adjusted to near zero by adding 8 wt% TiO2 to α alumina ceramics. A dielectric constant (ℇr) of 10.81, a high Q× f value of 338 000 GHz (measured at 14 GHz), and a temperature coefficient of resonant frequency (τf) of 1.3 ppm/°C were obtained for nano-scaled α alumina with 8 wt% TiO2 sintered at 1350°C for 4 h. Sintered ceramic samples were also characterized by X-ray diffraction and scanning electron microscopy. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
26. Low-Dielectric Loss Characteristics of Nd(Co1/2Ti1/2)O3 Ceramics at Microwave Frequencies.
- Author
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Tseng, Ching-Fang, Huang, Cheng-Liang, and Hsu, Cheng-Hsing
- Subjects
- *
CERAMICS , *DIELECTRICS , *NEODYMIUM , *MICROWAVES , *MICROSTRUCTURE , *POWDERS - Abstract
The microwave dielectric properties and the microstructures of Nd(Co1/2Ti1/2)O3 (NCT) ceramics using starting powders of Nd2O3, CoO, and TiO2 prepared by the conventional solid-state route have been researched. The dielectric constant values (ℇr) saturated at 24.8–27. Quality factor ( Q× f) values of 37 900–140 000 (at 9 GHz) and the measured τf values ranging from −45 to −48 ppm/°C can be obtained when the sintering temperatures are in the range of 1410°–1500°C. The ℇr value of 27, the Q× f value of 140 000 (at 9 GHz) and the τf value of −46 ppm/°C were obtained for NCT ceramics sintered at 1440°C for 4 h. For applications of high selective microwave ceramic resonator, filter, and antenna, NCT is proposed as a suitable material candidate. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
27. Microwave Dielectric Properties of Sintered Alumina Using Nano-Scaled Powders of α Alumina and TiO2.
- Author
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Huang, Cheng-Liang, Wang, Jun-Jie, and Huang, Chi-Yuen
- Subjects
ALUMINUM oxide ,SINTERING ,DIELECTRICS ,MICROWAVES ,NANOSTRUCTURED materials ,POWDERS ,TITANIUM dioxide - Abstract
The microstructure and the microwave dielectric properties of nano-scaled α alumina (α-Al
2 O3 ) ceramics with various added amounts of nano-scaled TiO2 have been investigated. The sintering temperature of nano-scaled α alumina can be effectively lowered by increasing the TiO2 content. The Q× f values of nano-scaled α alumina could be tremendously boosted by adding an appropriate amount of TiO2 . However, introducing excessive TiO2 into the alumina ceramics would instead lead to a decrease in the Q× f values. The phases of TiO2 and Al2 TiO5 co-existed at 1350°C, and the maximum Q× f value appeared right after the eradication of TiO2 phase at 1400°C. Consequently, increasing the TiO2 content to 0.5 wt% yielded a Q× f value of 680 000 GHz (measured at 14 GHz) for nano-scaled α alumina prepared at 1400°C for duration of 4 h. In addition, a very low loss tangent (tan δ) of 2 × 10−5 was also obtained at 14 GHz. The τf value is strongly correlated to the compositions and can be controlled through the existing phases. In fact, τf could be adjusted to near zero by adding 8 wt% TiO2 to α alumina ceramics. A dielectric constant (ℇr ) of 10.81, a high Q× f value of 338 000 GHz (measured at 14 GHz), and a temperature coefficient of resonant frequency (τf ) of 1.3 ppm/°C were obtained for nano-scaled α alumina with 8 wt% TiO2 sintered at 1350°C for 4 h. Sintered ceramic samples were also characterized by X-ray diffraction and scanning electron microscopy. [ABSTRACT FROM AUTHOR]- Published
- 2007
- Full Text
- View/download PDF
28. Pseudoelliptic bandpass filter realized using coupled stepped-impedance resonators with tapped I/O.
- Author
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Tsai, Jsung-Ta and Huang, Cheng-Liang
- Subjects
- *
BANDPASS filters , *STRIP transmission lines , *ELECTRIC impedance , *ELECTRIC resonators , *ELECTRIC filters - Abstract
A tapped combline bandpass filter composed of two coupled stepped-impedance resonators (SIRs) and with tapped lines fed in/out is modeled. The admittance matrix for the entire circuit has been derived from the four-port coupled-line impedance and admittance matrices. The obtained admittance matrix is suitable for the design of a stepped-impedance combline filter, in which the coupled-line length, as opposed to the previous work, is not restricted. The most effective miniaturization for the filter is achieved by setting the critical condition (θ1=θ2+θ3) for the cases of K>1. Without using the cross-coupling resonator structure, the simulation result and the manipulation reveal the potential of this configuration to realize a pseudoelliptic bandpass filtering response. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 105–109, 2000. [ABSTRACT FROM AUTHOR]
- Published
- 2000
- Full Text
- View/download PDF
29. Intense Red Photoluminescence Emission of Sol-Gel-Derived Nanocrystalline Mg2 TiO4 Thin Films.
- Author
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Ho, Yi ‐ Da, Su, Chia ‐ Hui, Huang, Cheng ‐ Liang, and Srivastava, A.
- Subjects
PHOTOLUMINESCENCE ,MAGNESIUM compounds ,THIN films ,DOPED semiconductors ,HEAT treatment of metals ,SOL-gel processes ,NANOCRYSTALS ,PHOTONIC band gap structures - Abstract
In this work, undoped Mg
2 TiO4 thin films were fabricated on p-type Si(111) substrates by the sol-gel method, and the red photoluminescence (PL) of the films is introduced and discussed. According to the experimental results, the red emission appears when the films have been thermally treated at higher temperatures, which have a long range and well-organized crystalline arrangement. Furthermore, to have better realization of the red emission mechanism of Mg2 TiO4 films, the optical band gap of Mg2 TiO4 ( Eg Mg2TiO4 ) was estimated at ~3.7 eV; furthermore, 325 nm (corresponding energy, hν = 3.82 eV > Eg Mg2TiO4 ) and 633 nm (corresponding energy, hν = 1.96 eV < Eg Mg2TiO4 ) excited light sources were used to clarify the position of the defect levels. In addition, the influence of annealing atmospheres ( O2 , air, and vacuum) on the red emission of our samples is also discussed. A significant variety of red emissions can be found between these annealing conditions: the red emission can be effectively enhanced by O2 annealing, but weakened by vacuum annealing. Results reveal that the red emission of Mg2 TiO4 thin films may be highly dependent on the completeness of the O-X-O (X = Mg, Ti) bonds. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
30. Enhanced Device Performances of Blue‐Emitting PLEDs Coupled with Silver‐Nanoicosahedrons.
- Author
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Chen, Sy‐Hann, Huang, Cheng‐Liang, Cheng, Bo‐Han, Ku, Hao‐Jung, Hsiao, Hsin‐I, and Kao, Po‐Ching
- Subjects
- *
PERFORMANCE of light emitting diodes , *CHEMICAL reduction , *PHOTOCHEMISTRY , *SILVER nanoparticles , *ICOSAHEDRA - Abstract
Silver‐nanoicosahedron particles (AgNIPs) are produced by chemical reduction and photochemical methods and doped into the hole transport layer (HTL) or emissive layer (EML) of blue‐emitting polymer light‐emitting diodes (PLEDs) to improve their luminous efficiency. The optimal distributed‐densities of the AgNIPs are determined from current density–voltage–luminance measurements at different doping concentrations. The AgNIP dopant doses that maximize the average luminous efficiency of the proposed PLED are 6.71 µg cm−2 in EML (achieving 3.48 cd A−1) and 6.88 µg cm−2 in HTL (achieving 3.35 cd A−1). Although the luminous efficiencies of the blue‐emitting PLEDs fabricated by both doping methods are not significantly different, the maximum plasmonic enhancement (around 30‐fold) of the blue‐emitting PLED with AgNIPs in EML is red‐shifted to the green region (≈530 nm in the electroluminescence spectrum), seriously degrading the luminescent monochromaticity of the blue‐emitting PLED. The maximum plasmonic enhancement (around 33‐fold) of blue‐emitting PLED with AgNIPs in HTL occurred at 430 nm, overlapping the localized surface‐plasmon resonance extinctions of the AgNIPs in HTL (425 nm), thus favoring the enhancement of fluorescence emission. Therefore, to enhance the large‐area emission of blue‐emitting PLEDs, the AgNIPs should be doped in the HTL rather than the EML. Chemical reduction and photochemical methods are used to fabricate silver‐nanoicosahedron particles (AgNIPs) with the desired localized surface plasmon resonance (LSPR) wavelength. Owing to the LSPR effect, directly doping into the hole transport layer or emissive layer with AgNIPs can lead to substantial enhancement in the luminance and efficacy of polymer light‐emitting diodes. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
31. Microwave Dielectric Properties of (1 − <italic>x</italic>)(Mg0.95Ni0.05)TiO3–<italic>x</italic>(Ca0.8Sr0.2)TiO3 Ceramic System With Near‐Zero Temperature Coefficient.
- Author
-
Shen, Chun‐Hsu, Huang, Cheng‐Liang, Chen, Wei‐Ting, and Pan, Chung‐Long
- Abstract
The microwave dielectric properties of the (1 −
x )(Mg0.95Ni0.05)TiO3–x (Ca0.8Sr0.2)TiO3 ceramic system prepared by mixed oxide route have been investigated. The crystal structures and the microstructures of the ceramics were characterized by means X‐ray and scanning electron microscopy. The microwave dielectric properties are strongly related to the density and matrix of the specimen. Combination of (Mg0.95Ni0.05)TiO3 (ilmenite‐type structure) and (Ca0.8Sr0.2)TiO3 (perovskite‐structured) forms a two‐phase system and leads to a near‐zero temperature coefficient (τf). With increasingx , the quality factor (Q ×f ) decreased and dielectric constant (εr) increased. A new microwave dielectric material 0.95(Mg0.95Ni0.05)TiO3–0.05(Ca0.8Sr0.2)TiO3, possessing excellent microwave dielectric properties with a dielectric constant (εr) of 21.68, a quality factor (Q ×f ) of 94,000 (GHz) and a temperature coefficient (τf) of approximately −5.2 ppm/°C at 1275°C for 4 h, is proposed as a suitable candidate material for microwave applications requiring low dielectric loss. [ABSTRACT FROM AUTHOR]- Published
- 2011
- Full Text
- View/download PDF
32. ChemInform Abstract: High-Q Microwave Dielectrics in the (Mg.
- Author
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Huang, Cheng-Liang, Chien, Yu-Hua, Tai, Chen-Yi, and Huang, Chi-Yuen
- Published
- 2011
- Full Text
- View/download PDF
33. ChemInform Abstract: Photodissociation and Photoisomerization of Small Aromatic Molecules in a Molecular Beam.
- Author
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Huang, Cheng-Liang, Jiang, Jyh-Chiang, Lin, Sheng Hsien, Lee, Yuan T., and Ni, Chi-Kung
- Published
- 2002
- Full Text
- View/download PDF
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