41 hasil untuk "Li-Jen Chen"

HRTF Adjustments with Audio Quality Assessments

Shu-Nung YAO; Li Jen CHEN

Archives of Acoustics, Vol. 38 No. 1 · 2013 · Inggris · DOAJ Scopus

There are an increasing number of binaural systems embedded with head-related transfer functions (HRTFs), so listeners can experience virtual environments via conventional stereo loudspeakers or head- phones. As HRTFs vary from person to person, it is difficult to select appropriated HRTFs from…

The Discrepancy Between Simulation and Observation of Electric Fields in Collisionless Shocks

Lynn B. Wilson; Li-Jen Chen; Vadim Roytershteyn

Frontiers in Astronomy and Space Sciences, Vol. 7 · 2021 · Inggris · DOAJ Scopus

Recent time series observations of electric fields within collisionless shocks have shown that the fluctuating, electrostatic fields can be in excess of one hundred times that of the quasi-static electric fields. That is, the largest amplitude electric fields occur at high frequencies, not low. In…

Doxorubicin-Induced Cardiac Toxicity Is Mediated by Lowering of Peroxisome Proliferator-Activated Receptor δ Expression in Rats

Zhih-Cherng Chen; Li-Jen Chen; Juei-Tang Cheng

PPAR Research, Vol. 2013 · 2013 · Inggris · DOAJ Scopus

The present study investigates the changes of peroxisome proliferator-activated receptors δ (PPARδ) expression and troponin phosphorylation in heart of rats which were treated with doxorubicin (DOX). Wistar rats which were treated with DOX according to a previous method. The protein levels of PPARδ…

Drivers of Magnetic Field Amplification at Oblique Shocks: In Situ Observations

Hadi Madanian; Imogen Gingell; Li-Jen Chen dkk.

The Astrophysical Journal Letters, Vol. 965 No. 1 · 2024 · Inggris · DOAJ Scopus

Collisionless shocks are ubiquitous structures throughout the Universe. Shock waves in space and astrophysical plasmas convert the energy of a fast-flowing plasma to other forms of energy, including thermal and magnetic energies. Plasma turbulence and high-amplitude electric and magnetic…

Correlating the interplanetary factors to distinguish extreme and major geomagnetic storms

Ragini Balachandran; Li-Jen Chen; Shan Wang dkk.

Earth and Planetary Physics, Vol. 5 No. 2 · 2021 · Inggris · DOAJ Scopus

We investigate the correlation between Disturbance Storm Time (Dst) characteristics and solar wind conditions for the main phase of geomagnetic storms, seeking possible factors that distinguish extreme storms (minimum Dst

Oblique propagation and temperature effects on the resonant right-hand ion beam instability

Ari Le; Li-Jen Chen; Blake Wetherton dkk.

Frontiers in Astronomy and Space Sciences, Vol. 9 · 2023 · Inggris · DOAJ Scopus

The resonant right-hand instability (RHI) is often the dominant mode driven by reflected ions upstream of Earth’s quasi-parallel bow shock. In the tradition of Peter Gary, this paper further explores the right-hand instability using numerical solutions of the plasma dispersion relation and…

Interplanetary Magnetic Field By Controlled Alfvén Wings at Earth During an Encounter of a Coronal Mass Ejection

Yuxi Chen; Chuanfei Dong; Li‐Jen Chen dkk.

Geophysical Research Letters, Vol. 52 No. 6 · 2025 · Inggris · DOAJ Scopus

Abstract On 24 April 2023, an ICME reached Earth's orbit. The solar wind density dropped to 0.3 amu/cc while the IMF strength was about 25 nT. As a result, the solar wind flow transitions to a sub‐Alfvénic state with an Alfvén Mach number of 0.4. We carry out global magnetohydrodynamic simulations…

Magnitude of Short-wavelength Electric Field Fluctuations in Simulations of Collisionless Plasma Shocks

Vadim Roytershteyn; Lynn B. Wilson III; Li-Jen Chen dkk.

The Astrophysical Journal, Vol. 992 No. 1 · 2025 · Inggris · DOAJ Scopus

Large-amplitude electrostatic fluctuations are routinely observed by spacecraft upon traversal of collisionless shocks in the heliosphere. Kinetic simulations of shocks have struggled to reproduce the amplitude of such fluctuations, complicating efforts to understand their influence on energy…

Kinetic properties of bursty bulk flow events

Li‐Jen Chen; G. K. Parks; M. McCarthy dkk.

Geophysical Research Letters, Vol. 27 No. 13 · 2000 · Inggris · DOAJ Scopus

Particle distributions of bursty bulk flow (BBF) events in the central plasma sheet regions show that the high earthward mean velocity comes from a combination of energetic ion flux increases (>few keV) in the earthward direction and decreases of similar energy fluxes in the tailward direction. The…

Foreshock Ultralow Frequency Waves at Mars: Consequence on the Particle Acceleration Mechanisms at the Martian Bow Shock

Nahuel Andrés; Norberto Romanelli; Christian Mazelle dkk.

The Astrophysical Journal, Vol. 979 No. 1 · 2025 · Inggris · DOAJ Scopus

Using Mars Atmosphere and Volatile EvolutioN Magnetometer observations, we report the first statistical study of ultralow frequency (ULF) waves at the Martian foreshock. The analyzed foreshock ULF wave events are observed in the 0.008–0.086 Hz frequency range, with nearly circular and elliptical…

Cardiac Peroxisome Proliferator-Activated Receptor δ (PPARδ) as a New Target for Increased Contractility without Altering Heart Rate

Zhih-Cherng Chen; Kung Shing Lee; Li-Jen Chen dkk.

PLoS ONE, Vol. 8 No. 5 · 2013 · Inggris · PLOS Scopus

Background and Aims: Agents having a positive inotropic effect on the heart are widely used for the treatment of heart failure. However, these agents have the side effect of altering heart rate. It has been established that peroxisome proliferator-activated receptor δ (PPARδ) is mediated in cardiac…

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Multiscale hybrid modeling of the impact response of the Earth’s magnetotail to ionospheric O+ outflow

Yuri A. Omelchenko; Christopher Mouikis; Jonathan Ng dkk.

Frontiers in Astronomy and Space Sciences, Vol. 10 · 2023 · Inggris · DOAJ Scopus

Ionospheric outflow plays an important role in coupling the ionosphere with the solar wind-magnetosphere system. Previous multi-fluid MHD studies explored the global influence of oxygen ions of ionospheric origin (O+) on magnetospheric dynamics. A detailed exploration of the interaction of…

Measurements of diffusion coefficient of methane in water/brine under high pressure

Yen-An Chen; Che-Kang Chu; Yan-Ping Chen dkk.

Terrestrial, Atmospheric and Oceanic Sciences, Vol. 29 No. 5 · 2018 · Inggris · DOAJ Scopus

The diffusion coefficient of methane in water plays an important role in the formation and dissociation of methane hydrate. However, most of the previous studies on the diffusion coefficient of methane in brine are performed at room temperature and low pressures, which is quite different from the…

Activation of β-Adrenoceptors by Dobutamine May Induce a Higher Expression of Peroxisome Proliferator-Activated Receptors δ (PPARδ) in Neonatal Rat Cardiomyocytes

Ming-Ting Chou; Shih-Hsiang Lo; Kai-Chun Cheng dkk.

The Scientific World Journal, Vol. 2012 · 2012 · Inggris · DOAJ Scopus

Recent evidence showed the role of peroxisome proliferator-activated receptors (PPARs) in cardiac function. Cardiac contraction induced by various agents is critical in restoring the activity of peroxisome proliferator-activated receptors δ (PPARδ) in cardiac myopathy. Because dobutamine is an…

Decrease of PPARδ in Type-1-Like Diabetic Rat for Higher Mortality after Spinal Cord Injury

Cheng-Chia Tsai; Kung-Shing Lee; Sheng-Hsien Chen dkk.

PPAR Research, Vol. 2014 · 2014 · Inggris · DOAJ Scopus

Changes in the peroxisome proliferator-activated receptors-δ (PPARδ) expression in rats after spinal cord injury (SCI) have been previously reported. Diabetic animals show a higher mortality after SCI. However, the relationship between the progress of diabetes and PPARδ in SCI remains unknown. In…

Heliocentric Distance and Solar Activity Dependence of Sustained Quasi-radial Interplanetary Magnetic Field Occurrence

Brandon L. Burkholder; Li-Jen Chen; Norberto Romanelli dkk.

The Astrophysical Journal, Vol. 953 No. 1 · 2023 · Inggris · DOAJ Scopus

Planets close to their stars experience an interplanetary magnetic field (IMF) that is dominantly quasi-radial. Our solar system serves as a laboratory to study how the occurrence of quasi-radial IMF varies away from the star and under different stellar activities. Furthermore, on time and spatial…

MMS Insights into Coronal Mass Ejection–driven Sub-Alfvénic Solar Wind at 1 au

Harsha Gurram; Li-Jen Chen; Matthew R. Argall dkk.

The Astrophysical Journal, Vol. 1003 No. 2 · 2026 · Inggris · DOAJ Scopus

We report the properties of electron distributions and turbulence during a coronal mass ejection (CME) in 2023 April observed by Magnetospheric Multiscale Mission. The CME exhibits a clear sheath and magnetic cloud (MC), and within the MC, the solar wind becomes sub-Alfvénic for 2 hr. We…

Stability and Characteristics of Lower-hybrid Drift Waves: Dependence on Electron Beta and Cross-field Relative Drift

Jongsoo Yoo; Hantao Ji; Jonathan Ng dkk.

The Astrophysical Journal, Vol. 1000 No. 2 · 2026 · Inggris · DOAJ Scopus

Lower-hybrid drift waves (LHDWs) are frequently observed microinstabilities in both space and laboratory plasmas. Despite decades of study, the relationship between electrostatic (ES-LHDW) and electromagnetic (EM-LHDW) variants and the plasma parameters controlling their stability remains unclear…

Molecular Dynamics Study of Clathrate-like Ordering of Water in Supersaturated Methane Solution at Low Pressure

Rodion V. Belosludov; Kirill V. Gets; Ravil K. Zhdanov dkk.

Molecules, Vol. 28 No. 7 · 2023 · Inggris · DOAJ Scopus

Using molecular dynamics, the evolution of a metastable solution for “methane + water” was studied for concentrations of 3.36, 6.5, 9.45, 12.2, and 14.8 mol% methane at 270 K and 1 bar during 100 ns. We have found the intriguing behavior of the system containing over 10,000 water molecules: the…