Search results for: Qinghua Lai

Items from 1 to 20 out of 27 results

chapter

Test on the prototype of a multiple-beam reflector antenna subsystem

Qinghua Lai, Chu Gao, Xiaotao Wang, Chen Zhang

2017 47th European Microwave Conference (EuMC) > 1179 - 1182

2017 47th European Microwave Conference (EuMC)

This paper presents the test on a prototype of a multiple-beam reflector antenna subsystem. That subsystem is developed for payload on broadband communication satellites. Design considerations and part of early experimental results have previously been reported. The following context focuses on the calibration method, the improved test procedure and the related results.

chapter

The optimization of sparse conformal array based on modified particle swarm optimization

Qingchao Zhu, Qinghua Lai, Jia Fang, Mouping Jin

2017 IEEE International Conference on Computational Electromagnetics (ICCEM) > 263 - 265

2017 IEEE International Conference on Computational Electromagnetics (ICCEM)

In order to optimize the radiation characteristics of conformal array in which elements' active amplitudes are equal, the HPSO and MOHPSO are introduced in this paper. Thoughts of intersection and variation are introduced into BPSO and MOHPSO is constructed upon HPSO. The HPSO algorithm is used to optimize the single-objective problems including optimization of gain in one scanning direction for conformal...

article

Bimetallic overlayer catalysts with high selectivity and reactivity for furfural hydrogenation

Chen Zhang, Qinghua Lai, Joseph H. Holles

Catalysis Communications > 2017 > 89 > C > 77-80

Silica-supported platinum overlayer on nickel (Ni@Pt) or copper (Cu@Pt) catalysts were synthesized and tested for furfural hydrogenation. H₂ chemisorption and an ethylene hydrogenation descriptor showed weakened H₂ binding strength of both overlayer catalysts compared to pure Pt, consistent with literature predictions. Cu@Pt showed higher turnover frequencies of furfural hydrogenation compared to...

article

Hydrodeoxygenation of guaiacol over Ni@Pd and Ni@Pt bimetallic overlayer catalysts

Qinghua Lai, Chen Zhang, Joseph H. Holles

Applied Catalysis A: General > 2016 > 528 > C > 1-13

First principle computational studies have predicted that formation of Pd or Pt overlayer on Ni base metal would cause a negative shift of the d-band center of surface Pd or Pt, resulting in reduced binding strength for adsorbed species. In this paper, silica alumina supported Ni@Pd and Ni@Pt overlayer catalysts were synthesized via directed deposition technique and tested for hydrodeoxygenation of...

chapter

A conformal low-profile cavity-backed slot antenna array

Yunfei Qiang, Lin Guo, Jing Miao, Qinghua Lai, more

2016 CIE International Conference on Radar (RADAR) > 1 - 3

2016 CIE International Conference on Radar (RADAR)

A conformal low-profile cavity-backed slot antenna array is proposed in this paper. This proposed antenna array has 8-element cavity-backed slot antenna. The operating bandwidth of the proposed antenna array is ranging from 0.96f₀ to 1.04f₀ (where the f₀ is center frequency of the target band) with the voltage standing wave ratio (VSWR) less than 2. Moreover, the depth of the cavity is only about...

chapter

A digital beam-forming multiple-beam reflector antenna subsystem for GEO communication satellites

Qinghua Lai, Chu Gao, Tianjie Peng, Zhenhua Liu, more

2016 46th European Microwave Conference (EuMC) > 866 - 869

2016 46th European Microwave Conference (EuMC)

This paper reports on the development of a multiple-beam reflector antenna subsystem applied for geosynchronous earth orbit (GEO) communication satellites. The subsystem is composed of two Gregorian reflector antennas, one operating in Ka band for uplink connections and the other in K band for downlink path. Each antenna consists of a large scaled feed array to provide the capability of wide angle...

article

Ir@Pt bimetallic overlayer catalysts for aqueous phase glycerol hydrodeoxygenation

Chen Zhang, Qinghua Lai, Joseph H. Holles

Applied Catalysis A: General > 2016 > 526 > C > 113-125

Silica-alumina supported bimetallic overlayer catalysts of platinum on Ir (Ir@Pt) were synthesized using the directed deposition technique to investigate the modification of the Pt catalytic properties. Weakened hydrogen adsorption strength was obtained for Ir@Pt overlayer catalysts compared to pure platinum using hydrogen chemisorption and an ethylene hydrogenation descriptor reaction, consistent...

chapter

The optimization of conformal array based on the CVCPSO

Qingchao Zhu, Qinghua Lai

2016 IEEE International Conference on Electronic Information and Communication Technology (ICEICT) > 482 - 484

2016 IEEE International Conference on Electronic Information and Communication Technology (ICEICT)

In order to optimize the radiation performance of conformal array, the CVCPSO is introduced in this paper. The amplitude of elements can be optimized by the CVCPSO when the arrangement form is settled. The CVCPSO is much easier to find the global optimal position while BPSO shows a weak ability to escape from regional optimal values. Results show that the array optimized by the CVCPSO presents lower...

chapter

DFT approach to arbitrary planar antenna arrays

Chu Gao, Qinghua Lai

2016 IEEE International Conference on Electronic Information and Communication Technology (ICEICT) > 454 - 457

2016 IEEE International Conference on Electronic Information and Communication Technology (ICEICT)

A method to compute patterns of arbitrary planar antenna arrays based on DFT (Discrete Fourier Transform) is proposed. By complex Fourier series expansion, irregular arrays are approximated to regular arrays. And array patterns are obtained by applying DFT. Examples are provided to illustrate the proposed method. A comparison between the proposed method and the series summation method is performed...

chapter

A novel S band dual circularly polarized antenna array for airborne satellite communication applications

Chu Gao, Xiaolin Zhang, Qinghua Lai

2016 IEEE International Conference on Microwave and Millimeter Wave Technology (ICMMT) > 2 > 692 - 694

2016 IEEE International Conference on Microwave and Millimeter Wave Technology (ICMMT)

A novel S band dual circularly polarized antenna array with 12 elements is presented for airborne satellite communication applications. The antenna array is composed of microstrip patches, 3dB hybrids and dividers. The simulated and measured results show that an impedance bandwidth of 14% (VSWR<2) is achieved. Radiation patterns with low cross polarization are achieved. The overall size of the...

chapter

A design of conformal dipole array for aircraft applications

Yunfei Qiang, Lin Guo, Miao Jing, Qinghua Lai

2016 IEEE International Conference on Microwave and Millimeter Wave Technology (ICMMT) > 1 > 464 - 466

2016 IEEE International Conference on Microwave and Millimeter Wave Technology (ICMMT)

A design of conformal dipole antenna array for aircraft applications is presented. This 6-element array is conformed to the wing of the aircraft. Furthermore, it is shown numerically that the proposed conformal array exhibits good VSWR and fine radiation properties in the operation band. The active VSWR is less than 1.6 without beam scanning for 0.88ƒ₀ to 1.1ƒ₀ (where the ƒ₀ is center frequency of...

chapter

A 60GHz four-channel receiver front-end for multiple-beam phased array

Xiaodong He, Pei Li, Yuefei Dai, Tongli Yuan, more

2016 IEEE International Conference on Microwave and Millimeter Wave Technology (ICMMT) > 2 > 901 - 903

2016 IEEE International Conference on Microwave and Millimeter Wave Technology (ICMMT)

This paper presents a millimeter-wave 4-channel receiver front-end with 6-bit phase shifter and 6-bit attenuator for multiple-beam phased array for limited scan on geosynchronous communication satellites. Major design consideration is the reduction of weight, volume and power consumption, while maintaining the electric performance. Measurement results are provided for validation of the design.

chapter

A prototype of feed subsystem for a mutilple-beam array-fed reflector antenna

Qinghua Lai, Pei Li, Xiaopeng Lu, Chu Gao

2015 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting > 238 - 239

2015 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting

This paper introduces the design of a feed subsystem for a multiple-beam array-fed reflector antenna. The prototype is composed of 37 circularly polarized horns and a complicated RF switch matrix. The feed horns are divided into four interleaved groups. Each time four adjacent feed horns, i.e., each from one group, are selected by the RF switch matrix to connect to a signal processor where the delivered...

article

Using chemo-drugs or irradiation to break immune tolerance and facilitate immunotherapy in solid cancer

Yawen Zheng, Yan Dou, Lili Duan, Changsheng Cong, more

Cellular Immunology > 2015 > 294 > 1 > 54-59

The immunity is dual host-protective and tumor-promoting in cancer development and progression. Many immune suppressive cells and cytokines in microenvironment can prevent cytotoxic T lymphocytes (CTL) and natural killer cells (NK) from killing tumor cells. Chemotherapy drugs and irradiation have been reported helpful in breaking immune tolerance and creating microenvironment for adoptive cell therapy...

article

Review of the progress in preparing nano TiO2: An important environmental engineering material

Yan Wang, Yiming He, Qinghua Lai, Maohong Fan

Journal of Environmental Sciences > 2014 > 26 > 11 > 2139-2177

TiO ₂ nanomaterial is promising with its high potential and outstanding performance in photocatalytic environmental applications, such as CO ₂ conversion, water treatment, and air quality control. For many of these applications, the particle size, crystal structure and phase, porosity, and surface area influence the activity of TiO ₂ dramatically. TiO ₂ nanomaterials...

chapter

A mm-wave multiple-beam phased array breadboard for GEO-LEO inter-satellite links

Qinghua Lai, Pei Li, Mouping Jin, Chu Gao, more

2014 IEEE MTT-S International Microwave Symposium (IMS2014) > 1 - 3

2014 IEEE/MTT-S International Microwave Symposium - MTT 2014

This paper presents a prototype of a V band multiple-beam phased array, which is to be used on a GEO satellite as receiving antenna for GEO-LEO inter-satellite links. This antenna is capable of radiating four independent scan beams to support simultaneous data links between the GEO platform and four LEO satellites. Relevant measures have been introduced to reduce gross weight and power consumption...

chapter

A prototype of 60 GHz multiple-beam phased array for limited scan

Qinghua Lai, Pei Li, Mouping Jin, Chu Gao, more

2013 European Radar Conference > 311 - 314

2013 European Radar Conference (EuRAD)

This paper presents a prototype of millimeter-wave multiple-beam phased array for limited scan on geosynchronous communication satellites. Major design considerations are put on the reduction of system weight, volume and power consumption, while maintaining the electric performance. Measurement results are provided for validation of the design.

chapter

A prototype of 60 GHz multiple-beam phased array for limited scan

Qinghua Lai, Pei Li, Mouping Jin, Chu Gao, more

2013 European Microwave Conference > 1623 - 1626

2013 European Microwave Conference (EuMC)

article

Nanocomposites of TiO ₂ and Reduced Graphene Oxide as Efficient Photocatalysts for Hydrogen Evolution

Wenqing Fan, Qinghua Lai, Qinghong Zhang, Ye Wang

The Journal of Physical Chemistry C > 2011 > 115 > 21 > 10694 - 10701

chapter

On the transition from radiating to guiding behavior of the half-mode substrate integrated waveguide

Qinghua Lai, Christophe Fumeaux, Wei Hong

2010 Asia-Pacific Microwave Conference > 1601 - 1604

2010 Asia Pacific Microwave Conference (APMC 2010)

The transition from radiative to guiding behavior of a half-mode substrate integrated waveguide (HMSIW) is studied throughout this work. The electric near-field distribution in the substrate plane is first demonstrated at different frequencies over the mono-mode operation band and is then related to far-field radiation patterns. The observation shows that the HMSIW, as a semi-open transmission line,...

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ANTENNA MEASUREMENTS (5)
ANTENNA RADIATION PATTERNS (5)
MULTIPLE-BEAM (5)
DIELECTRIC RESONATOR ANTENNAS (4)
FREQUENCY MEASUREMENT (4)
DIELECTRICS (3)
GAIN (3)
PHASED ARRAY (3)
RADIATION EFFICIENCY (3)
SUBSTRATE INTEGRATED WAVEGUIDES (3)
WHEELER CAP METHOD (3)
ADSORPTION (2)
ANTENNA FEEDS (2)
ANTENNAS AND PROPAGATION (2)
BIMETALLIC (2)
CONFORMAL ARRAY (2)
CROSS-POLARIZATION (2)
DIELECTRIC RESONATOR ANTENNA (2)
DIELECTRIC SUBSTRATES (2)
ELECTROMAGNETIC WAVEGUIDES (2)
FREQUENCY (2)
HALF MODE SUBSTRATE INTEGRATED WAVEGUIDE (2)
HALF-MODE SUBSTRATE INTEGRATED WAVEGUIDE (2)
HALF-MODE SUBSTRATE INTEGRATED WAVEGUIDE (HMSIW) (2)
HMSIW (2)
HYDRODEOXYGENATION (2)
LIMITED SCAN (2)
MICROSTRIP (2)
MILLIMETER-WAVE (2)
OVERLAYER (2)
PHASED ARRAYS (2)
PLANAR ARRAYS (2)
PROTOTYPES (2)
RADIO FREQUENCY (2)
SUBSTRATES (2)
SWITCHES (2)
WAVEGUIDES (2)
ABSTRACTS (1)
AEROSPACE ELECTRONICS (1)
AIRCRAFT (1)
AIRCRAFT PROPULSION (1)
AMPLITUDE (1)
ANTENNA ARRAYS (1)
ANTENNA FEED (1)
APERTURE ANTENNAS (1)
ARBITRARY PLANAR ANTENNA ARRAY (1)
ARRAY PATTERN (1)
ATTENUATION (1)
ATTENUATION CONSTANT (1)
ATTENUATION MEASUREMENT (1)
BANDWIDTH (1)
BPSO (1)
C BAND (1)
CALIBRATION (1)
CAVITY RESONATORS (1)
CAVITY-BACKED SLOT ANTENNA (1)
CHEMO-DRUG (1)
CIRCULAR DISK (1)
CIRCULAR POLARIZATION (1)
CLOSED-FORM SOLUTION (1)
COMMUNICATIONS (1)
CONFORMAL ANTENNA (1)
CONNECTORS (1)
COPLANAR WAVEGUIDES (1)
CRITICAL FREQUENCY POINT (1)
CUTOFF FREQUENCY (1)
CVCPSO (1)
DFT (1)
DIELECTRIC LOSSES (1)
DIELECTRIC MEASUREMENTS (1)
DIELECTRIC RESONATOR ANTENNA (DRA) (1)
DIELECTRIC RESONATOR ANTENNAS (DRAS) (1)
DIGITAL BEAMFORMING (1)
DIPOLE ANTENNAS (1)
DIRECTIVITY METHOD (1)
DIRECTIVITY/GAIN METHOD (1)
ELECTRIC FIELDS (1)
ELECTRIC NEAR-FIELD DISTRIBUTION (1)
EQUATIONS (1)
FAR-FIELD RADIATION PATTERNS (1)
FEEDING STRUCTURE (1)
FEEDS (1)
FIELD DISTRIBUTION (1)
FINITE SAMPLING (1)
FORMATION MECHANISM (1)
FOURIER SERIES (1)
FREQUENCY 60 GHZ (1)
FRINGING FIELDS (1)
FURFURAL HYDROGENATION (1)
GLYCEROL (1)
GUAIACOL (1)
GUIDED WAVE STRUCTURE (1)
HPSO (1)
HYDROGEN CHEMISORPTION (1)
IMMUNE TOLERANCE (1)
IMMUNOTHERAPY (1)
INDUCTORS (1)
INTER-SATELLITE LINKS (1)
IRIDIUM (1)
IRRADIATION (1)
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ieee (21)
Elsevier (5)
ACS (1)

INFONA - science communication portal

Search results for: Qinghua Lai

Test on the prototype of a multiple-beam reflector antenna subsystem

The optimization of sparse conformal array based on modified particle swarm optimization

Bimetallic overlayer catalysts with high selectivity and reactivity for furfural hydrogenation

Hydrodeoxygenation of guaiacol over Ni@Pd and Ni@Pt bimetallic overlayer catalysts

A conformal low-profile cavity-backed slot antenna array

A digital beam-forming multiple-beam reflector antenna subsystem for GEO communication satellites

Ir@Pt bimetallic overlayer catalysts for aqueous phase glycerol hydrodeoxygenation

The optimization of conformal array based on the CVCPSO

DFT approach to arbitrary planar antenna arrays

A novel S band dual circularly polarized antenna array for airborne satellite communication applications

A design of conformal dipole array for aircraft applications

A 60GHz four-channel receiver front-end for multiple-beam phased array

A prototype of feed subsystem for a mutilple-beam array-fed reflector antenna

Using chemo-drugs or irradiation to break immune tolerance and facilitate immunotherapy in solid cancer

Review of the progress in preparing nano TiO2: An important environmental engineering material

A mm-wave multiple-beam phased array breadboard for GEO-LEO inter-satellite links

A prototype of 60 GHz multiple-beam phased array for limited scan

A prototype of 60 GHz multiple-beam phased array for limited scan

Nanocomposites of TiO ₂ and Reduced Graphene Oxide as Efficient Photocatalysts for Hydrogen Evolution

On the transition from radiating to guiding behavior of the half-mode substrate integrated waveguide

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