document

Slight Multielement Doping-Induced Structural Order-Disorder Transition for High-Performance Layered Na-Ion Oxide Cathodes

Guo, Hao (author), Zhao, C. (author), Gao, Jianxiang (author), Yang, Wenyun (author), Hu, Xufeng (author), Ma, Xiaobai (author), Jiao, Xuesheng (author), Yang, Jinbo (author), Sun, Kai (author), Chen, Dongfeng (author)

To realize concurrently the high-energy density and excellent cycling stability, maximum utilization of redox couple, minimization of detrimental phase transition, and structural degradation of O3-type layered oxide cathodes are critical for developing Na-ion batteries. Ni²⁺/Ni⁴⁺ redox couple showing multielectron...

journal article 2023

document

Life cycle assessment of material footprint in recycling: A case of concrete recycling

Zhang, Chunbo (author), Hu, Mingming (author), van der Meide, Marc (author), Di Maio, F. (author), Yang, Xining (author), Gao, Xiaofeng (author), Li, Kai (author), Zhao, Hailong (author), Li, Chen (author)

Meeting the current demand for concrete requires not only mining tons of gravel and sand, but also burning large amounts of fossil fuel resources in cement kilning. Consequently, concrete recycling is crucial to achieving a material-efficient society, especially with the application of various categories of concrete and the goal of phasing...

journal article 2023

document

Gal/Xgal U/LDB Spectroscopic/Stratospheric THz Observatory:: GUSTO

Walker, C (author), Kusela, C. (author), Young, A (author), Verts, W. (author), Gao, J.R. (author), Hu, Qing (author), Silva, J. R.G. (author), Mirzaei, B. (author), Laauwen, Wouter (author)

Gal/Xgal U/LDB Spectroscopic/ Stratospheric THz Observatory (GUSTO) is a NASA Explorers Mission of Opportunity that will make large scale maps of the Milky Way and Large Magellanic Cloud in three important interstellar lines: [CII], [OI], and [NII] at 158, 63, and 205 μm, respectively. During its ~75 day stratospheric (~36 km) flight, GUSTO’s 0...

conference paper 2022

document

Points of Interest (POI): a commentary on the state of the art, challenges, and prospects for the future

Psyllidis, A. (author), Gao, Song (author), Hu, Yingjie (author), Kim, Eun-Kyeong (author), McKenzie, Grant (author), Purves, Ross (author), Yuan, May (author), Andris, Clio (author)

In this commentary, we describe the current state of the art of points of interest (POIs) as digital, spatial datasets, both in terms of their quality and affordings, and how they are used across research domains. We argue that good spatial coverage and high-quality POI features — especially POI category and temporality information — are key for...

journal article 2022

document

4.7 THz asymmetric beam multiplexer for GUSTO

Mirzaei, B. (author), Gan, Y. (author), Finkel, M. (author), Groppi, Christopher (author), Young, Abram (author), Walker, Christopher (author), Hu, Qing (author), Gao, J.R. (author)

A full demonstration of the Fourier phase grating used as 4.7 THz local oscillator (LO) multiplexer for Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory (GUSTO) is presented in this paper, including its design, modeling, tolerance analysis, and experimental characterizations of the angular and intensity distributions among 2 ×...

journal article 2021

document

New innovations in pavement materials and engineering: A review on pavement engineering research 2021

Chen, Jiaqi (author), Dan, Hancheng (author), Ding, Yongjie (author), Gao, Y. (author), Guo, Meng (author), Guo, Shuaicheng (author), Han, Bingye (author), Hong, Bin (author), Hou, Yue (author), Hu, Chichun (author), Hu, Jing (author), Huyan, Ju (author), Jiang, Jiwang (author), Jiang, Wei (author), Li, Cheng (author), Liu, Pengfei (author), Liu, Yu (author), Liu, Zhuangzhuang (author), Lu, Guoyang (author), Ouyang, Jian (author), Qu, Xin (author), Ren, Dongya (author), Wang, Chao (author), Wang, Chaohui (author), Wang, Dawei (author), Wang, Di (author), Wang, Hainian (author), Wang, Haopeng (author), Xiao, Yue (author), Xing, Chao (author), Xu, Huining (author), Yan, Yu (author), Yang, Xu (author), You, Lingyun (author), You, Zhanping (author), Yu, Bin (author), Yu, Huayang (author), Yu, Huanan (author), Zhang, Henglong (author), Zhang, Jizhe (author), Zhou, Changhong (author), Zhou, Changjun (author), Zhu, Xingyi (author)

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges. In the past 10 years, the pavement infrastructure strongly supports the rapid development of the global social economy. New theories, new methods, new technologies and new materials related to pavement engineering are emerging....

review 2021

document

Hypericin: Source, Determination, Separation, and Properties

Zhang, Jie (author), Gao, Ling (author), Hu, Jie (author), Wang, Chongjun (author), Hagedoorn, P.L. (author), Li, Ning (author), Zhou, Xing (author)

Hypericin is a naturally occurring compound synthesized by certain species of the genus Hypericum, with various pharmacological effects. It is used as a natural photosensitizing agent with great potential in photodynamic therapy. This review discusses the latest results about the biosynthetic pathways and chemical synthetic routes to obtain...

journal article 2020

document

28 GHz Quadrature Frequency Generation Exploiting Injection-Locked Harmonic Extractors for 5G Communications

Gao, Z. (author), Hu, Yizhe (author), Siriburanon, Teerachot (author), Staszewski, R.B. (author)

This paper proposes a mm-wave quadrature frequency generator using injection-locked harmonic extractors (HEs) incorporated with quadrature class-F oscillators. While maintaining high output levels at 28 GHz, the utilization of injection locking technique improves the effective quality ($Q$)-factor and helps to achieve a fundamental harmonic...

conference paper 2019

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81 supra-THz beams generated by a Fourier grating and a quantum cascade laser

Gan, Yuner (author), Mirzaei, B. (author), Silva, Jose R.G. (author), Khalatpour, Ali (author), Hu, Qing (author), Groppi, Christopher (author), Siles, Jose V. (author), van der Tak, Floris (author), Gao, J.R. (author)

Large heterodyne receiver arrays (~100 pixel) allow astronomical instrumentations to map more area within limited space mission lifetime. One challenge is to generate multiple local oscillator (LO) beams. Here, we succeeded in generating 81 beams at 3.86 THz by combining a reflective, metallic Fourier grating with an unidirectional antenna...

journal article 2019

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8-beam local oscillator array at 4.7 THz generated by a phase grating and a quantum cascade laser

Mirzaei, B. (author), Silva, J. R.G. (author), Hayton, D (author), Groppi, C (author), Kao, T. Y. (author), Hu, Q. (author), Reno, John L. (author), Gao, J.R. (author)

We present an 8-beam local oscillator (LO) for the astronomically significant [OI] line at 4.7 THz. The beams are generated using a quantum cascade laser (QCL) in combination with a Fourier phase grating. The grating is fully characterized using a third order distributed feedback (DFB) QCL with a single mode emission at 4.7 THz as the input....

journal article 2017

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A 4.7 THz HEB QCL receiver for STO2

Hayton, Darren J. (author), Gao, J.R. (author), Laauwen, Wouter (author), Mirzaei, B. (author), Khudchenko, Andrey (author), Kloosterman, Jenna L. (author), Paveliev, Dmitry (author), Hu, Qing (author), Kao, Wilt (author), Vax, Vladimir (author), Walker, Chris K. (author)

We report on a 4.7 THz heterodyne receiver designed for high resolution spectroscopy of the astronomically important neutral oxygen (OI) line at 4.745 THz. The receiver is based around a hot electron bolometer (HEB) mixer and quantum cascade laser (QCL) local oscillator. This receiver has been developed to fly on the Stratospheric Terahertz...

conference paper 2017

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Simultaneous frequency locking and monitoring using a bi-directional THz quantum cascade laser

Mirzaei, B. (author), van Marrewijk, N.T. (author), Hayton, D (author), Gao, J.R. (author), Kao, T. Y. (author), Hu, Q. (author), Reno, John L. (author)

We have performed frequency locking of a dual, forward reverse emitting 3rd order distributed feedback quantum cascade laser (QCL) at 3.5 THz. By using both directions of THz emission in combination with two gas cells and two power detectors, we can for the first time perform frequency stabilization, while monitor the frequency locking...

conference paper 2017

document

Frequency Locking and Monitoring Based on Bi-directional Terahertz Radiation of a 3rd-Order Distributed Feedback Quantum Cascade Laser

Van Marrewijk, N. (author), Mirzaei, B. (author), Hayton, D. (author), Gao, J.R. (author), Kao, T.Y. (author), Hu, Q. (author), Reno, J.L. (author)

We have performed frequency locking of a dual, forward reverse emitting third-order distributed feedback quantum cascade laser (QCL) at 3.5 THz. By using both directions of THz emission in combination with two gas cells and two power detectors, we can for the first time perform frequency stabilization, while monitor the frequency locking quality...

journal article 2015

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Phase locking of a 3.4 THz third-order distributed feedback quantum cascade laser using a room-temperature superlattice harmonic mixer

Hayton, D.J. (author), Khudchenko, A. (author), Pavelyev, D.G. (author), Hovenier, J.N. (author), Baryshev, A. (author), Gao, J.R. (author), Kao, T.Y. (author), Hu, Q. (author), Reno, J.L. (author), Vaks, V. (author)

We report on the phase locking of a 3.4 THz third-order distributed feedback quantum cascade laser (QCL) using a room temperature GaAs/AlAs superlattice diode as both a frequency multiplier and an internal harmonic mixer. A signal-to-noise level of 60?dB is observed in the intermediate frequency signal between the 18th harmonic of a 190.7?GHz...

journal article 2013

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Beam and phase distributions of a terahertz quantum cascade wire laser

Cui, M. (author), Hovenier, J.N. (author), Ren, Y. (author), Vercruyssen, N. (author), Gao, J.R. (author), Kao, T.Y. (author), Hu, Q. (author), Reno, J.L. (author)

We report on both measurements and simulations of the beam profile and wavefront of a single-mode, 3.5?THz quantum cascade wire laser, incorporating a lateral corrugated metal-metal waveguide, 3rd-order distributed feedback grating. The intrinsic wavefront was measured by using a Hartmann wavefront sensor (HWS) without any optical components...

journal article 2013

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Hot electron bolometer heterodyne receiver with a 4.7-THz quantum cascade laser as a local oscillator

Kloosterman, J.L. (author), Hayton, D.J. (author), Ren, Y. (author), Kao, T.Y. (author), Hovenier, J.N. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Hu, Q. (author), Walker, C.K. (author), Reno, J.L. (author)

We report on a heterodyne receiver designed to observe the astrophysically important neutral atomic oxygen [OI] line at 4.7448?THz. The local oscillator is a third-order distributed feedback quantum cascade laser operating in continuous wave mode at 4.741?THz. A quasi-optical, superconducting NbN hot electron bolometer is used as the mixer. We...

journal article 2013

document

Frequency and amplitude stabilized terahertz quantum cascade laser as local oscillator

Ren, Y. (author), Hayton, D.J. (author), Hovenier, J.N. (author), Cui, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Shi, S.C. (author), Kao, T.Y. (author), Hu, Q. (author), Reno, J.L. (author)

We demonstrate an experimental scheme to simultaneously stabilize the frequency and amplitude of a 3.5 THz third-order distributed feedback quantum cascade laser as a local oscillator. The frequency stabilization has been realized using a methanol absorption line, a power detector, and a proportional-integral-derivative (PID) loop. The amplitude...

journal article 2012

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Frequency locking of single-mode 3.5-THz quantum cascade lasers using a gas cell

Ren, Y. (author), Hovenier, J.N. (author), Cui, M. (author), Hayton, D.J. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Shi, S.C. (author), Kao, T.Y. (author), Hu, Q. (author), Reno, J.L. (author)

We report frequency locking of two 3.5-THz third-order distributed feedback (DFB) quantum cascade lasers (QCLs) by using methanol molecular absorption lines, a proportional-integral-derivative controller, and a NbN bolometer. We show that the free-running linewidths of the QCLs are dependent on the electrical and temperature tuning coefficients....

journal article 2012

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High-resolution heterodyne spectroscopy using a tunable quantum cascade laser around 3.5 THz

Ren, Y. (author), Hovenier, J.N. (author), Higgins, R. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Shi, S.C. (author), Klein, B. (author), Kao, T.Y. (author), Hu, Q. (author), Reno, J.L. (author)

A frequency tunable terahertz heterodyne spectrometer, based on a third-order distributed feedback quantum cascade laser as a local oscillator, has been demonstrated by measuring molecular spectral lines of methanol (CH3OH) gas at 3.5 THz. By varying the bias voltage of the laser, we achieved a tuning range of ? 1?GHz of the lasing frequency,...

journal article 2011

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Terahertz heterodyne spectrometer using a quantum cascade laser

Ren, Y. (author), Hovenier, J.N. (author), Higgins, R. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Shi, S.C. (author), Bell, A. (author), Klein, B. (author), Williams, B.S. (author), Kumar, S. (author), Hu, Q. (author), Reno, J.L. (author)

A terahertz (THz) heterodyne spectrometer is demonstrated based on a quantum cascade laser (QCL) as a local oscillator (LO) and an NbN hot electron bolometer as a mixer, and it is used to measure high-resolution molecular spectral lines of methanol (CH3OH) between 2.913–2.918 THz. The spectral lines are taken from a gas cell containing methanol...

journal article 2010