SEARCH · Engineering Papers
Results for “PHOSPHORUS”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Polarization-resolved black phosphorus [bP] / molybdenum disulfide [MoS 2 ] mid-wave infrared photodiodes with high detectivity at room temperature
Infrared photodetectors are currently subject to a rapidly expanding application space, with an increasing demand for compact, sensitive and inexpensive detectors. Despite continued advancement, technological factors limit the widespread usage of such detectors, specifically, the need for cooling and the high costs associated with processing of III-V/II-VI semiconductors. Here, black phosphorous (bP)/MoS 2 heterojunction photodiodes are explored as mid-wave infrared (MWIR) detectors. Although previous studies have demonstrated photodiodes using bP, here we significantly improve the performance, showing that such devices can be competitive with conventional MWIR photodetectors. By optimizing the device structure and light management, we demonstrate a two-terminal device that achieves room-temperature external quantum efficiencies (ηe) of 35% and specific detectivities (D*) as high as 1.1 × 10 10 cm Hz 1/2 W -1 in the MWIR region. Furthermore, by leveraging the anisotropic optical properties of bP we demonstrate the first bias-selectable polarization-resolved photodetector that operates without the need for external optics.
Effects of nitrogen fertilization and bioenergy crop type on spatial distributions of extracellular hydrolases associated with nitrogen and phosphorus acquisition
Not provided.
Atom probe tomographic mapping directly reveals the atomic distribution of phosphorus in resin embedded ferritin
In this study, we report the atomic-scale analysis of biological interfaces using atom probe tomography. Embedding the protein ferritin in an organic polymer resin lacking nitrogen provided chemical contrast to visualize atomic distributions and distinguish organic-organic and organic-inorganic interfaces. The sample preparation method can be directly extended to further enhance the study of biological, organic and inorganic nanomaterials relevant to health, energy or the environment.
Distributions of iron, phosphorus and sulfur along trichomes of the cyanobacteria Trichodesmium
Abstract not provided
Interfacial electron transfer in photoanodes based on phosphorus(v) porphyrin sensitizers co-deposited on SnO2 with the Ir(III)Cp* water oxidation precatalyst
Explore the source record for details and available documents.
Divergent uranium- versus phosphorus-based reduction of Me 3 SiN 3 with steric modification of phosphido ligands
We describe an example of a two-electron metal- and ligand-based reduction of Me 3 SiN 3 using uranium( iv ) complexes with varying steric properties. With uranium-based reduction, a U( vi ) intermediate is isolated.
Third time's the charm: intricate non-centrosymmetric polymorphism in Ln SiP 3 ( Ln = La and Ce) induced by distortions of phosphorus square layers
Complex polymorphic relationships in the Ln SiP 3 ( Ln = La and Ce) family of compounds are reported.
Defect dynamics in two-dimensional black phosphorus under argon ion irradiation
Classical molecular dynamics simulations show that production, accumulation, and evolution of defects in monolayer phosphorene can be precisely controlled by varying fluence of noble gas ion radiation.
Semiconducting silicon–phosphorus frameworks for caging exotic polycations
Silicon phosphides with a new structure have been synthesized. These salt inclusion materials contain exotic polycations such as [Ba 6 Cl] 11+ . The structure and properties are investigated.
Analysis of the bonding in tetrahedrane and phosphorus-substituted tetrahedranes
The bonding structures of tetrahedrane, phosphatetrahedrane, diphosphatetrahedrane and triphosphatetrahedrane are studied by employing an intrinsic quasi-atomic orbital analysis. Ethane, cyclopropane and tetrahedral P 4 are employed as reference systems. The orbital analysis is paired with the computation of strain energies via isodesmic reactions. The results show that the increase in geometric strain upon transition from ethane to cyclopropane to tetrahedrane weakens the CC bonds, despite leading to shorter C–C interatomic distances. With the increase in strain, the orbitals centered on C and involved in the bonding of the cage structure are observed to have elevated p-character, and the orbital structure of C deviates from sp 3 hybridization. The systematic substitution of CH groups by P atoms in the cage structure of tetrahedrane leads to stronger CC bonds, larger angles in the cage structures of the resulting phosphatetrahedranes, lower p-character in the orbitals involved in the bonding of the cages, and lower strain energies. It is found that P is more amenable to strained molecular arrangements than is C, and that the propensity of a given atom to hybridize s and p functions, or the lack thereof, has implications in the stability of molecules with strained geometries. The combination of the calculations presented here with the existing literature provides insight into the apparent propensity of tetrahedrane and P 4 to ‘break’ their tetrahedral structures. Trends in the bonding interactions, such as bond strengths, s- and p-orbital characters and charge transfer are identified and related to the strain energy observed in each of the analyzed systems.
Flexible interactions of the rare-earth elements Y, La, and Lu with phosphorus in metallacyclohexane rings
A new dianionic bis(amino)phosphine ligand was synthesized and the corresponding metallacyclohexane complexes of Y, La, and Lu were studied using NMR experiments.
Increasing phosphorus loss despite widespread concentration decline in US rivers
The loss of phosphorous (P) from the land to aquatic systems has polluted waters and threatened food production worldwide. Systematic trend analysis of P, a nonrenewable resource, has been challenging, primarily due to sparse and inconsistent historical data. Here, we leveraged intensive hydrometeorological data and the recent renaissance of deep learning approaches to fill data gaps and reconstruct temporal trends. We trained a multitask long short-term memory model for total P (TP) using data from 430 rivers across the contiguous United States (CONUS). Trend analysis of reconstructed daily records (1980–2019) shows widespread decline in concentrations, with declining, increasing, and insignificantly changing trends in 60%, 28%, and 12% of the rivers, respectively. Concentrations in urban rivers have declined the most despite rising urban population in the past decades; concentrations in agricultural rivers however have mostly increased, suggesting not-as-effective controls of nonpoint sources in agriculture lands compared to point sources in cities. TP loss, calculated as fluxes by multiplying concentration and discharge, however exhibited an overall increasing rate of 6.5% per decade at the CONUS scale over the past 40 y, largely due to increasing river discharge. Results highlight the challenge of reducing TP loss that is complicated by changing river discharge in a warming climate.
Manganese co-localizes with calcium and phosphorus in Chlamydomonas acidocalcisomes and is mobilized in manganese-deficient conditions
Not Available