A scalable software package for time series reconstruction of remote sensing datasets on the Google Earth Engine platform

Spatiotemporal residual noise in terrestrial earth observation products, often caused by unfavorable atmospheric conditions, impedes their broad applications. Most users prefer to use gap-filled remote sensing products with time series reconstruction (TSR) algorithms. Applying currently available implementations of TSR to large-volume...

Floodplain Connecting Channels as Critical Paths for Hydrological Connectivity of Deltaic River Networks

A river bifurcation is critical for distributing water, sediment and nutrients to the downstream branches of deltaic river networks. However, the downstream branches of a bifurcation can be linked by a connecting channel cutting through deltaic floodplains. The floodplain connecting channel as a downstream control can affect water...

Strain-engineered S-HfSe₂ monolayer as a promising gas sensor for detecting NH₃: A first-principles study

The development of high-performance gas sensing materials is one of the development trends of new gas sensor technology. In this work, in order to predict the gas-sensitive characteristics of HfSe₂ and its potential as a gas-sensitive material, the interactions of nonmetallic element (O, S, Te) doped HfSe₂ monolayer and...

The Longitudinal Profile of a Prograding River and Its Response to Sea Level Rise

River longitudinal profile, a key morphological characteristic of the river channel, is subject to river mouth progradation. Given the increasing influence of human activities and climate change on this critical downstream control, understanding its effects on the evolution of the longitudinal profile is imperative. A general theoretical...

Wave Controls on Deltaic Shoreline‐Channel Morphodynamics: Insights From a Coupled Model

It is widely recognized that waves inhibit river mouth progradation and reduce the avulsion<br/>timescale of deltaic channels. Nevertheless, those effects may not apply to downdrift‐deflected channels. In this study, we developed a coupled model to explore the effects of wave climate asymmetry and alongshore sediment bypassing on shoreline...

Long-Term Cumulative Effects of Intra-Annual Variability of Unsteady River Discharge on the Progradation of Delta Lobes: A Modeling Perspective

Rivers, regardless of their scales and geographic locations, are characterized with natural and human-induced variability in their discharges. While previous studies have established the effects of both interannual and intra-annual variabilities of unsteady river discharge on delta morphological evolution, the long-term cumulative effects of...

Combined Effects of Unsteady River Discharges and Wave Conditions on River Mouth Bar Morphodynamics

River mouth bar formation, a key process in fluvial-deltaic morphodynamics, is subject to both river discharge and waves. Given the increasing variability of both forcings under continuous climate change and human interventions, assessing their combined effects on mouth bar formatio n is an imperative issue. In this study, an extensive set of...

Efficient water reduction with gallium phosphide nanowires

Photoelectrochemical hydrogen production from solar energy and water offers a clean and sustainable fuel option for the future. Planar III/V material systems have shown the highest efficiencies, but are expensive. By moving to the nanowire regime the demand on material quantity is reduced, and new materials can be uncovered, such as wurtzite...

Beam and phase distributions of a terahertz quantum cascade wire laser

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...

Frequency and amplitude stabilized terahertz quantum cascade laser as local oscillator

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...

Terahertz wavefronts measured using the Hartmann sensor principle

We demonstrate for the first time that the Hartmann wavefront sensor (HWS) principle can be applied for characterizing the wavefronts of terahertz (THz) electromagnetic radiation. The THz Hartmann wavefront sensor consists of a metallic plate with an array of holes and a twodimensional scanable pyro-electric detector. The THz radiation with...

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

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....