Searched for:
(1 - 17 of 17)
document
Gao, Y. (author), Dong, Jianfei (author), Isabella, O. (author), Santbergen, R. (author), Tan, Hairen (author), Zeman, M. (author), Zhang, G. (author)
Dynamic photovoltaic (PV) greenhouses integrate sustainable energy generation with plant cultivation, offering more possibilities of energy production and microclimate control by adjusting the sun-tracking angles. Previous studies on PV greenhouses barely paid attention to the PV partial shading effects, and rarely recorded the performance...
journal article 2019
document
Gao, Yuan (author), Qiao, Tiezhu (author), Zhang, Haitao (author), Yang, Yi (author), Pang, Y. (author), Wei, Hongyan (author)
During the operation of the belt conveyor, measuring speed of the belt conveyor is vital to the safe and efficient operation. In the existing measuring speed system, the measurement instrument is required contacting with the surface of the belt. The contact measurement method cannot avoid the occurrence of measuring error caused by slipping...
journal article 2019
document
Gao, P. (author), Zhang, Tong Sheng (author), Wei, Jiang Xiong (author), Yu, Qi Jun (author)
Graded blended cement made of graded Portland cement (PC), blast furnace slag (BFS) and fly ash (FA) is attractive for cement production. For manufacturing graded blended cement, a suitable mathematical expression should be introduced to describe the particle size distribution (PSD) of its components and control the quality of graded blended...
journal article 2018
document
Dong, H. (author), Zhang, H. (author), Zuo, Y. (author), Gao, P. (author), Ye, G. (author)
Mercury intrusion porosimetry (MIP) measurements are widely used to determine pore throat size distribution (PSD) curves of porous materials. The pore throat size of porous materials has been used to estimate their compressive strength and air permeability. However, the effect of sample size on the determined PSD curves is often overlooked....
journal article 2018
document
Gao, Y. (author), Dong, J. (author), Isabella, O. (author), Santbergen, R. (author), Tan, H. (author), Zeman, M. (author), Zhang, G.Q. (author)
Vertical space bears great potential of solar energy especially for congested urban areas, where photovoltaic (PV) windows in high-rise buildings can contribute to both power generation and daylight harvest. Previous studies on sun-tracking PV windows strayed into the trade-off between tracking performance and mutual shading, failing to achieve...
journal article 2018
document
Gao, Y. (author), Dong, J. (author), Isabella, O. (author), Zeman, M. (author), Zhang, G (author)
Diverse solar irradiance spectra can be observed under different conditions of time, date, location, weather, etc. Since the solar irradiance spectrum is required by certain scientific and engineering applications, obtaining accurate spectral data is essential. Measurements by spectrophotometers are able to achieve accurate real-time data with...
conference paper 2016
document
Zhou, Zeng (author), Coco, Giovanni (author), Townend, IH (author), Olabarrieta, Maitane (author), van der Wegen, M. (author), Gong, Zheng (author), D’Alpaos, Andrea (author), Gao, Shu (author), Jaffe, Bruce E. (author), Gelfenbaum, Guy (author), He, Qing (author), Wang, Yaping (author), Lanzoni, Stefano (author), Wang, Zhengbing (author), Winterwerp, J.C. (author), Zhang, Changkuan (author)
Morphodynamic equilibrium is a widely adopted yet elusive concept in the eld of geomorphology of coasts, rivers and estuaries. Based on the Exner equation, an expression of mass conservation of sediment, we distinguish three types of equilibrium dened as static and dynamic, of which two dierent types exist. Other expressions such as statistical...
journal article 2016
document
Gao, L. (author), Zhang, L.M. (author), Chen, H.X. (author)
Due to hilly terrain and frequent heavy rainstorms, debris flow is one of the most common and catastrophic hazards in Hong Kong. To mitigate the debris flow risk, prediction of the magnitude and consequence of debris flow is essential. The objective of this paper is to simulate debris flow hazards in a study area in Hong Kong. Assessment of the...
conference paper 2015
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Tao, Y. (author), Gao, D.W. (author), Wang, H.Y. (author), Zhang, X. (author), Ghasimi, S.M.D. (author), Ozgun, H. (author), Ersahin, M.E. (author), Zhou, Z.B. (author), Liu, G. (author), Temudo, M.F. (author), Kloek, J. (author), Spanjers, H. (author), De Kreuk, M.K. (author), Van Lier, J.B. (author)
conference paper 2014
document
Hayton, D.J. (author), Gao, J.R. (author), Kooi, J.W. (author), Ren, Y. (author), Zhang, W. (author), De Lange, G. (author)
We report on a method to stabilize a hot electron bolometer (HEB) mixer at 2.5 THz. The technique utilizes feedback control of the local oscillator (LO) laser power by means of a swing-arm actuator placed in the optical beam path. We demonstrate that this technique yields a factor of 50 improvement in the spectroscopic Allan variance time which...
journal article 2012
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Ren, Y. (author), Gao, J.R. (author), Hovenier, J.N.Higgins, R. (author), Zhang, W. (author), Bell, A. (author), Klein, B. (author), Klapwijk, T.M. (author)
High-resolution heterodyne spectrometers operating at above 2 THz are crucial for detecting, e.g., the HD line at 2.7 THz and oxygen OI line at 4.7 THz in astronomy. The potential receiver technology is a combination of a hot electron bolometer (HEB) mixer and a THz quantum cascade laser (QCL) local oscillator (LO).Here we report the first...
conference paper 2010
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Zhang, W. (author), Gao, J.R. (author), Khosropanah, P. (author), Bansal, T. (author), Klapwijk, T.M. (author), Miao, W. (author), Shi, S.C. (author)
We report the sensitivity of a superconducting NbN hot electron bolometer mixer integrated with a tight spiral antenna at 5.3 THz. Using a measurement setup with black body calibration sources and a beam splitter in vacuo, and an antireflection coated Si lens, we obtained a double sideband receiver noise temperature of 1150 K, which is 4.5 times...
conference paper 2010
document
Zhang, W. (author), Khosropanah, P. (author), Gao, J.R. (author), Bansal, T. (author), Klapwijk, T.M. (author), Miao, W. (author), Shi, S.C. (author)
We report the measured sensitivities of a superconducting NbN hot electron bolometer (HEB) heterodyne receiver at 5.25 THz. Terahertz (THz) radiation is quasioptically coupled to a HEB mixer with a lens and a spiral antenna. Using a measurement setup with black body calibration sources and a beam splitter in vacuo, and an antireflection coated...
journal article 2010
document
Zhang, W. (author), Khosropanah, P. (author), Gao, J.R. (author), Kollberg, E.L. (author), Yngvesson, K.S. (author), Bansal, T. (author), Barends, R. (author), Klapwijk, T.M. (author)
We have measured the noise temperature of a single, sensitive superconducting NbN hot electron bolometer (HEB) mixer in a frequency range from 1.6 to 5.3 THz, using a setup with all the key components in vacuum. By analyzing the measured receiver noise temperature using a quantum noise (QN) model for HEB mixers, we confirm the effect of QN. The...
journal article 2010
document
Khosropanah, P. (author), Baryshev, A. (author), Zhang, W. (author), Jellema, W. (author), Hovenier, J.N. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Paveliev, D.G. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author), Klein, B. (author), Hesler, J.L. (author)
We demonstrate the phase locking of a 2.7 THz metal–metal waveguide quantum cascade laser (QCL) to an external microwave signal. The reference is the 15th harmonic, generated by a semiconductor superlattice nonlinear device, of a signal at 182 GHz, which itself is generated by a multiplier chain (x12) from a microwave synthesizer at ~15 GHz....
journal article 2009
document
Khosropanah, P. (author), Zhang, W. (author), Hovenier, J.N. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Amanti, M.I. (author), Scalari, G. (author), Faist, J. (author)
We report a heterodyne receiver using a superconducting NbN hot electron bolometer (HEB) integrated with a tight winding spiral antenna as mixer and a distributed feedback (DFB) terahertz quantum cascade laser (QCL) operating at 3.42 THz as local oscillator. The aim is to demonstrate the readiness of both devices for the detection of OH lines at...
journal article 2008
document
Wang, X.W. (author), Gao, F.L. (author), Zhang, X.M. (author), Ruan, B.Q. (author)
Water resources contribute greatly to human well being, both directly and indirectly. Water resources are irreplaceable natural resources, and are limited. However, due to a growing population and related economic development, the water demand from urban, industry and agriculture has increased dramatically. Water shortage has become one of the...
report 2002
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