145,435 research outputs found
Synergistic induced charge transfer switch by oxygen vacancy and pyrrolic nitrogen in MnFe2O4/g-C3N4 heterojunctions for efficient transformation of bicarbonate to acetate in photo-assisted MES
No full textInorganic carbon (HCO3-) was efficiently converted into acetate (204.4 ± 0.5 mM with a coulombic efficiency of 96 ± 3% over 24 days operation) in a photo-assisted microbial electrosynthesis system (MES) using a urea-treated MnFe2O4/g-C3N4 cathode and the nonphotosynthetic bacteria Serratia marcescens Q1. The remarkable photocatalytic performance of MnFe2O4/g-C3N4 heterojunction was resulted from the charge transfer mechanism switch (from type II to Z-scheme) induced by the synergistic effect of oxygen vacancies and pyrrolic N after urea treatment. The increased pyrrolic N was conductive to photoinduced electron transfer while the oxygen vacancies provided a higher fraction of surface-active sites for H2 evolution, which was metabolized in-situ with bicarbonate by S. marcescens Q1 to yield acetate via the Wood–Ljungdahl pathway. This study provides a simple and feasible strategy for switching the photocatalytic charge transfer in a spinel-based heterojunction and offers new insights for ingeniously synthesizing photocatalysts with high CO2 conversion in MES
Li-Ge data for: Machine Learning of Ab-initio Energy Landscapes for Crystal Structure Predictions
No full textEvolutionary algorithm structure search for Li-Ge crystal structures.
W. W. Tipton, C. A. Mathulis, and R. G. Hennig. Ab-initio prediction of the Li5Ge2 Zintl compound. Comp. Mater. Sci. 93, 133 (2014
Synthetic and structural investigations of some lithium thiolates and thiocarboxylates
No full textA series of closely related lithium aryl thiolates with pyridine as a donor ligand have been prepared. X-ray structure determination (Dr. W. Clegg) has shown that [PKSLi.(NC(_5)H(_5))] crystallises as an infinite chain polymer. Insertion of a methylene group between the phenyl ring and sulphur as in (PhCH(_2)SLi .NC(_5)H(_5). ] (_oo) produced an infinitely folded ladder polymer with Li-S rungs, while introduction of an 0-methyl group produces the monomeric complex [o-MeC(_6)H(_4)SLi .(NC(_5)H(_5))(_3)].The unusual symmetrical complex [Li(_14) (SCH(_2)Ph)(_12) S(TMEDA.)(_6)] has been prepared, in which a central sulphur atom is surrounded by a distorted cube of lithium atoms, each edge of which is bridged by a benzyl thiolate group such that the twelve S atoms form a cubo- octahedron: a further six Li atoms form a larger outer octahedron. When TMEDA is present in excess it appears that both PhSLi and PhCH(_2)SLi form dimeric compounds with a central Li(_2)S(_2) ring but structure determination of these complexes is incomplete.[PhOOSLi.TMEDA](_2)has been prepared and crystallises as a centrosymmetric dimer containing a chair shaped central eight membered (OOSLi)(_2) ring with the Li atoms out of the (COS)(-2), molecular plane. Lithiation of the related acids PhOOOH and PhCSSH has been carried out in the presence of TMEDA but crystal growth has so far been unsuccessful. Ab initio m.o. calculations on related model compounds are included. A preliminary study has been carried out on the lithiation of the thio-oxime (Ph(_2) C-NSH). Results were encouraging but detailed investigation is needed. The reaction of S(_4) N(_4) with BI(_3) produces, not the expected adduct, S(_4)N(_4) .BI(_3) , but an intractable polymer, empirical formula, S(_3)N(_3)BI. Other adducts of S(_4).N(_4) and (PhCN_2) S(_2))(_2), were prepared but were unsuitable for further reactions. The reaction of lithium borohydride and sulphur in THF to produce sulphurated lithium borohydride has been modified to give a controllable reaction. Further reaction with TMEDA gives clear orange crystals of a complex the composition of which is still unknown
Epeus G. W. Peckham & E. G. Peckham 1886
No full textGenus <i>Epeus</i> G. W. Peckham & E. G. Peckham, 1886 <p> Type species: <i>Evenus tener</i> Simon, 1877, from Philippines.</p>Published as part of <i>Lin, Yejie, Li, Shuqiang & Pham, Dinh-Sac, 2023, Taxonomic notes on some spider species (Arachnida: Araneae) from China and Vietnam, pp. 1-99 in Zoological Systematics 48 (1)</i> on page 61, DOI: 10.11865/zs.2023101, <a href="http://zenodo.org/record/10941307">http://zenodo.org/record/10941307</a>
Some Observations on the Construction of Space in the Prose of W. G. Sebald
No full textPierwodruk: „Białostockie Studia Literaturoznawcze” 2016, nr 8.This essay discusses the relationship between how space is constructed in the works of W. G. Sebald, and a fundamental characteristic of his texts, namely their hybridity. The author focuses, in particular, on the function of photography in Sebald’s narrations. Photographs, though themselves iconographic signs with strong referentiality, do not eliminate a strong textualization of space in Sebald’s works.Katedra Teorii Literatury, Uniwersytet Łódzki814115
Li-rich cathodes for rechargeable Li-based batteries: Reaction mechanisms and advanced characterization techniques
No full textDue to their high specific capacities beyond 250 mA h g-1, lithium-rich oxides have been considered as promising cathodes for the next generation power batteries, bridging the capacity gap between traditional layered-oxide based lithium-ion batteries and future lithium metal batteries such as lithium sulfur and lithium air batteries. However, the practical application of Li-rich oxides has been hindered by formidable challenges. To address these challenges, the understanding of their electrochemical behaviors becomes critical and is expected to offer effective guidance for both materials and cell development. This review aims to provide fundamental insights into the reaction mechanisms, electrochemical challenges and modification strategies of lithium-rich oxides. We first summarize the research history, the pristine structures, and the classification of lithium-rich oxides. Then we review the critical reaction mechanisms that are closely related to their electrochemical features and performances, such as lattice oxygen oxidation, oxygen vacancy formation, transition-metal migration, layered to spinel transitions, 'two-phase mechanism', and lattice evolution. These discussions are coupled with state-of-the-art characterization techniques. As a comparison, the anionic redox reactions of layered sodium transition metal oxides are also discussed. Finally, after a brief overview of the correlation among the aforementioned mechanisms, we provide perspectives on the rational design of lithium-rich oxides with high energy densities and long-term cycling stability. This journal i
Oxygen-redox activity in non-Li-excess W-doped LiNiO2 cathode
No full textThe desire to increase the energy density of stoichiometric layered LiTMO2 (TM = 3d transition metal) cathode materials has promoted investigation into their properties at high states of charge. Although there is increasing evidence for pronounced oxygen participation in the charge compensation mechanism, questions remain whether this is true O-redox, as observed in Li-excess cathodes. Through a high-resolution O K-edge resonant inelastic X-ray spectroscopy (RIXS) study of the Mn-free Ni-rich layered oxide, LiNi0.98W0.02O2, we demonstrate that the same oxidized oxygen environment exists in both Li-excess and non-Li-excess systems. The observation of identical RIXS loss features in both classes of compounds is remarkable given the differences in their crystallographic structure and delithiation pathways. This lack of a specific structural motif reveals the importance of electron correlation in the charge compensation mechanism for these systems and indicates how a better description of charge compensation in layered oxides is required to understand anionic redox for energy storage
A light-management film layer induces dramatically enhanced acetate production in photo-assisted microbial electrosynthesis systems
No full textA light-management system consisting of a Al-doped ZnO (AZO) film layer was combined for the first time with different bio-photocathodes (Serratia marcescens Q1 electrotroph immobilized on g-C3N4, MnFe2O4 or MnFe2O4/g-C3N4) to significantly enhance acetate production from bicarbonate in photo-assisted microbial electrosynthesis systems (MES). The AZO light-management system exhibiting optical properties independent of the light incident angle mitigated the shielding effect of light by electrotrophs, increasing light trapping and decreasing light reflection, ultimately allowing higher rates of photon absorption and redistributions of photons over the photo-active layers. As a result, more reducing equivalents as H2 produced up to 242% (g-C3N4/AZO-filter) and 543% (g-C3N4/AZO) increase in acetate production at coulombic efficiencies of 70% (g-C3N4/AZO-filter) and 81% (g-C3N4/AZO). The record high solar-to-acetate efficiency obtained with the MnFe2O4/g-C3N4/AZO biocathode was 3.20%. The light-management system proposed in this study opens a new promising way to construct efficient bio-photocathodes for inorganic carbon reduction in photo-assisted MES
Advanced nanophotonics for gas spectroscopy
No full textThis thesis introduces advanced nanophotonic integrated devices aimed at improving minia-turized, cost-effective multi-gas detection and on-chip spectroscopic systems. Traditional spectroscopic techniques often require bulky optical components and multiple detectors, limiting their scalability for multi-gas sensing. The proposed integrated duplexers and tri-plexers enable switching between lasers to detect multiple gases using a single system. The work focuses on the design and optimization of broadband angled multimode interference duplexers, directional coupler-based duplexers, and cascaded directional coupler-based tri-plexers for combining spectroscopically relevant wavelengths in the near-infrared region. The target gases include ammonia, methane, and carbon dioxide. Through comprehensive simulations and experimental investigations, the proposed on-chip designs demonstrate su-perior performance compared to existing solutions and have a unique advantage in terms of smaller footprint and improved coupling efficiency. DC-based duplexer has been success-fully integrated with laser and GRIN lens components, resulting in a ready-to-use module for multi-gas sensing applications.
A semi-integrated photonic sensing system is presented, exploiting on-chip waveguides with Quartz Enhanced Photoacoustic spectroscopy and Light induced thermoelastic spec-troscopy (LITES). Side-polished optical fibers are explored to enhance light-matter interac-tion path when detecting water vapor and methane gases using LITES method. To further improve integration of integrated nanophotonic devices with spectroscopic devices and to enhance light-matter interaction, a novel wave confinement approach is introduced using high-contrast grating hollow core waveguides. These waveguides feature a reflective sur-face that maintains high transmission while allowing gas flow through the sidewalls, mak-ing them particularly suitable for gas spectroscopic applications. They are specifically op-timized for methane sensing at a wavelength of 3.27 μm. The final goal of this thesis is to develop a complete system that integrates a multiplexer with integrated lasers and high-efficiency interaction pathways, such as hollow core waveguides, into a spectroscopic de-vice. This compact and integration-friendly design holds great promises for enabling the development of portable, high-precision, and real-time multi-gas sensing devices for appli-cations from industrial, agricultural to environmental monitoring
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