Wyszukiwarka
Filtry
wszystkich: 11426
wybranych: 9308
-
Katalog
- Publikacje 9308 wyników po odfiltrowaniu
- Czasopisma 729 wyników po odfiltrowaniu
- Konferencje 37 wyników po odfiltrowaniu
- Osoby 309 wyników po odfiltrowaniu
- Projekty 52 wyników po odfiltrowaniu
- Zespoły Badawcze 1 wyników po odfiltrowaniu
- Kursy Online 418 wyników po odfiltrowaniu
- Wydarzenia 16 wyników po odfiltrowaniu
- Dane Badawcze 556 wyników po odfiltrowaniu
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: MULTIFUNCTIONAL ENERGY STORAGE MATERIALS NANOSTRUCTURED MATERIALS BAND GAP TRANSFER LEARNING AB INITIO CALCULATIONS
-
Deep learning for ultra-fast and high precision screening of energy materials
PublikacjaSemiconductor materials for energy storage are the core and foundation of modern information society and play important roles in photovoltaic system, integrated circuit, spacecraft technology, lighting applications, and other fields. Unfortunately, due to the long experiment period and high calculation cost, the high-precision band gap (the basic characteristic parameter) of semiconductor is difficult to obtain, which hinders the...
-
Understanding the Electronic Structure and Optical Properties of Vacancy-Ordered Double Perovskite A2BX6 for Optoelectronic Applications
PublikacjaOver the past few years, metal halide perovskite solar cells have made significant advances. Currently, the single-junction perovskite solar cells reach a conversion efficiency of 25.7%. Perovskite solar cells with a wide band gap can also be used as top absorber layers in multi-junction tandem solar cells. We examined the dynamical and thermal stability, electronic structure, and optical features of In2PtX 6 (X = Cl, Br, and I)...
-
A facile method for Tauc exponent and corresponding electronic transitions determination in semiconductors directly from UV–Vis spectroscopy data
PublikacjaIn this work, a facile method allowing for estimation of the exponent in the Tauc equation directly from the UV–vis spectra is presented. It is based on the Taylor expansion of the logarithmic version of the Tauc equation. The Tauc exponent is calculated from the tangent slope of the absorption data. Knowledge of this coefficient provides information about the optical transition types and is used as an input for the calculations...
-
Linking optical and electronic properties to photoresponse of heterojunctions based on titania nanotubes and chromium, molybdenum, and tungsten oxides
PublikacjaThe development of photosensitization strategies for titanium dioxide is necessary for the enhancement of its optical and electronic properties towards its application potential in solar photoelectrochemistry. In this work, significant differences in the photosensitizing capability of the 6th group transition metal oxides applied on the surface of titania nanotubes are reported. For the first time, correlations between the experimentally...
-
An ab initio study of the excited states of the vinoxy radical
PublikacjaMetodą ab initio obliczone zostały powierzchnie energii potencjalnej oraz radialne sprzężenia nieadiabatyczne. Rozpatrzono podprzestrzeń dwóch aktywnych kątów zaangażowanych w proces fotodysocjacji. Opracowany został schemat kwaziadiabatyczny w sąsiedztwie przecięcia stożkowego. Przedyskutowano niektóre konsekwencje możliwego mechanizmu fotodysocjacji winoksylu z różnych ścieżek formacji.
-
Electronic structure and charge distribution in DyBa2Cu3O7: The ab initio approach
PublikacjaW pracy wykonano obliczenia kwantowomechaniczne struktury elektronowej nadprzewodzącego materiału DyBa2Cu3O7 (Dy123) metodą FP-LAPW (full potential - linearized augmented plane wave) w ramach formalizmu DFT (density functional theory) stosując przybliżenie GGA (generalized gradient approximation). Ze względu na silne oddziaływania korelacyjne elektronów 4f w atomie Dy zastosowano dodatkowo poprawkę kulombowską U w ramach modelu...
-
Phase change thermal energy storage – the experience of the materials preparation for the specific applications.
PublikacjaThermal energy storage and temperature stabilization is very important in many engineering applications. There are three kinds of thermal energy storage: sensible heat, latent heat and reversible chemical reaction heat. Phase change materials (PCM) absorb, store and release large amounts of energy in the form of latent heat, at constant temperature, called the transition temperature. Many innovative applications could be found...
-
The ab initio calculations of single nitrogen-vacancy defect center in diamond.
PublikacjaW artykule zaprezentowano rezultaty kwantowomechanicznych obliczeń ''ab initio'' struktury elektronowej defektu azot-wakans w diamencie. Do obliczeń wykorzystano model złożony z 63 atomów. Otrzymane wyniki zostały porównane z wcześniejszymi pracami teoretycznymi i doświadczalnymi.
-
Phase Change Thermal Energy Storage – The Experience of the Materials Preparation for the Specific Applications.
PublikacjaThermal energy storage and temperature stabilization is very important in many engineering applications. There are three kinds of thermal energy storage: sensible heat storage, latent heat storage and reversible chemical reaction heat storage. Phase change materials (PCM) absorb, store and release large amounts of energy in the form of latent heat, at constant temperature, called the transition temperature. The amount of heat...
-
Band structure, Born effective charges, and lattice dynamics of CuInS2 from ab initio calculations
Publikacja -
Isobutyl acetate: electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy and ab initio calculations
PublikacjaThe high-resolution vacuum ultraviolet photoabsorption spectrum of isobutyl acetate, C6H12O2, is presented here and was measured over the energy range 4.3–10.8 eV (290–115 nm). Valence and Rydberg transitions with their associated vibronic series have been observed in the photoabsorption spectrum and are assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. The measured...
-
Electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy and ab initio calculations of ethyl acetate
PublikacjaThe high-resolution vacuum ultraviolet photoabsorption spectrum of ethyl acetate, C4H8O2, is presented over the energy range 4.5−10.7 eV (275.5−116.0 nm). Valence and Rydberg transitions and their associated vibronic series observed in the photoabsorption spectrum, have been assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. Also, the photoabsorption cross sections...
-
Valence and Ionic Lowest-Lying Electronic States of Isobutyl Formate Studied by High-Resolution Vacuum Ultraviolet Photoabsorption, Photoelectron Spectroscopy, and Ab Initio Calculations
PublikacjaThe highest resolution vacuum ultraviolet photoabsorption spectrum of isobutyl formate, C5H10O2, yet reported is presented over the energy range 4.5−10.7 eV (275.5−118.0 nm) revealing several new spectral features. Valence and Rydberg transitions and their associated vibronic series observed in the photoabsorption spectrum have been assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator...
-
Control system for contactless electrical energy transfer with varying air gap
PublikacjaInductive power transfer (IPT) is a system by which electrical energy may be transmitted without electrical connection through a large air gap between coils. Systems usually considered in the literature are the ones with a constant air gap. The paper describes the analysis of IPT, which allows for supplying an electrical load in the conditions of slow, in relation to the dynamics of power supply, changes in the dimensions of the...
-
Dynamical properties of pnictide ZnSnP2 from ab initio calculations
Publikacja -
Organic-inorganic materials for fast charging-discharging processes in energy storage devices
PublikacjaPraca dotyczy materiału kompozytowego złożonego z poli(3,4-etylenodioksytiofenu) i heksacyjanokobaltanu żelaza. Materiał został otrzymany elektrochemicznie bezpośrednio na elektrodzie tytanowej metodą jednoetapowa z zawiesiny zawierającej monomer (EDOT) oraz Fe3[Co(CN)6]2 w postaci proszku. Warstwy pEDOT/FehcCo otrzymane potencjostatycznie ładunkiem od 0,6 do 1,5 C/cm2 charakteryzują się różną grubością (od 1,9 do 4 μm) zależną...
-
Ab Initio Study of the Electronic Spectrum of 7-Hydroxyquinoline
PublikacjaThe electronic spectrum of 7-hydroxyquinoline has been studied by using ab initio Multi-State Multi-Reference Møller-Plesset Second-Order Perturbation Theory (MSMRMP2). The energy range up to 6.5 eV is taken into consideration. The lowest π–π* transition is calculated to have an energy of 3.65 eV in good agreement with experimental data. Several other π–π* transitions are predicted to have excitation energies of 4.93, 5.20, 5.47,...
-
Powering the Future by Iron Sulfide Type Material (FexSy) Based Electrochemical Materials for Water Splitting and Energy Storage Applications: A Review
PublikacjaWater electrolysis is among the recent alternatives for generating clean fuels (hydrogen). It is an efficient way to produce pure hydrogen at a rapid pace with no unwanted by-products. Effective and cheap water-splitting electrocatalysts with enhanced activity, specificity, and stability are currently widely studied. In this regard, noble metal-free transition metal-based catalysts are of high interest. Iron sulfide (FeS) is one...
-
Limonene: electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, electron scattering, He(I) photoelectron spectroscopy and ab initio calculations
PublikacjaZbadano limonen metodami spektroskopii absorpcyjnej, elektronowej, fotojonizacyjnej. Wyniki porównano z obliczeniami ab initio. Otrzymano strukturę wibracyjną molekuły.
-
Valence and ionic lowest-lying electronic states of ethyl formate as studied by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy, and ab initio calculations
PublikacjaThe highest resolution vacuum ultraviolet photoabsorption spectrum of ethyl formate, C2H5OCHO, yet reported is presented over the wavelength range 115.0–275.5 nm (10.75–4.5 eV) revealing several new spectral features. Valence and Rydberg transitions and their associated vibronic series, observed in the photoabsorption spectrum, have been assigned in accordance with new ab initio calculations of the vertical excitation energies...
-
Ab initio and density functional theory calculations of proton affinities for volatile organic compounds
PublikacjaThe Hatree-Fock method with 6-311G** split-valence molecular orbitals basis sets and the density function theory-B3LYP have been applied to geometrical optimizations and calculations of total electronic, zero point vibrational energies and proton affinities at 298 K for volatile organic compounds. Calculated values of proton affinities are compared with experimental data.
-
Theoretical study of the photoelectron spectrum of ethyl formate: Ab initio and density functional theory investigation
PublikacjaThe first ionization energy and associated photoelectron spectrum of ethyl formate are investigated with quantum chemistry calculations. The geometries, harmonic vibrational frequencies and first ionization energy are computed at the Hartree-Fock (HF) and at the second order Moller-Plesset perturbation theory (MP2). Moreover, accurate ionization energies are obtained with the Coupled-Cluster theory including singles and doubles...
-
Polymer derived SiOC/Sn nanocomposites from a low-cost single source precursor as anode materials for lithium storage applications
PublikacjaMetal- based materials capable of lithium (Li) alloy formation are key to realization of the next generation of high-energy density anodes for Li-ion batteries, owing to their high storage capacity. Designing a good sup- porting matrix is essential for homogeneously nesting these metallic nanodomains, to effectively utilize their high capacity while tackling the volume expansion issues. Silicon oxycarbides (SiOC), obtained via...
-
Lattice dynamics and elasticity of silver thiogallate (AgGaS2) from ab initio calculations
Publikacja -
Ab initio Structure Determination of Mg10Ir19B16
PublikacjaOkreślono strukturę krystalograficzną nowego, nie-centrosymetrycznego nadprzewodzącego związku chemicznego, mg10ir19b16. Została zastosowana cała gama technik eksperymentalnych: dyfrakcja elektronowa, proszkowa dyfrakcja promieniowania rentgenowskiego, mikroskopia elektronowa wysokiej rozdzielczości, itd. Określenie struktury krystalograficznej było skrajnie trudne ponieważ jest to nowy, nieznany dotąd typ struktury krystalicznej,...
-
Ab initio Structure Determination of Mg10Ir19B16
Publikacja -
Recent advances of selected passive heat transfer intensification methods for phase change material-based latent heat energy storage units: A review
PublikacjaThe following article overviews recent studies regarding heat transfer enhancement methods, explicitly focusing on fins and coils utilization, in phase change material-based latent heat thermal energy storage systems. It discusses the influence of various geometrical and material parameters on the melting and solidification processes, as well as the orientation of the heat transfer surface within the storage tank. Additionally,...
-
Ab initio molecular treatment for charge transfer by S3+ ion on hydrogen.
PublikacjaPoliczono adiabatyczne potencjały oddziaływania między jonem siarki i wodoru. Dokonano obliczeń nieadiabatycznych sprzężeń pomiędzy tymi potencjałami. Obliczenia wykazały, że należy wziąć pod uwagę niezbadany wcześniej poziom energetyczny jonu siarki aby dokładnie wyjaśnić mechanizm przechwytu ładunku.
-
Minimal parameter implicit solvent model for ab initioelectronic-structure calculations
PublikacjaAbstract - We present an implicit solvent model for ab initio electronic-structure calculations which is fully self-consistent and is based on direct solution of the nonhomogeneous Poisson equation. The solute cavity is naturally defined in terms of an isosurface of the electronic density according to the formula of Fattebert and Gygi (J. Comput. Chem., 23 (2002) 662). While this model depends on only two parameters, we demonstrate...
-
Cu-Doped Layered Double Hydroxide Constructs the Performance-Enhanced Supercapacitor Via Band Gap Reduction and Defect Triggering
PublikacjaLayered double hydroxides (LDHs) are regarded as the excellent electrode materials for supercapacitors because of their high theoretical capacitance and abundance. However, the poor conductivity and limited reaction kinetics of LDHs restrict their practical application severely. Herein, Cu is chosen from groups VIII/IB/IIB as dopants for Co-based LDH (CuCo-LDH). The designed metal–organic framework-derived hierarchical CuCo-LDH...
-
Elastic scattering of electrons by water: An ab initio study
PublikacjaIn this work we devise a theoretical and computational method to compute the elastic scattering of electrons from a non-spherical potential, such as in the case of molecules and molecular aggregates. Its main feature is represented by the ability of calculating accurate wave functions for continuum states of polycentric systems via the solution of the Lippmann-Schwinger equation, including both the correlation effects and multi-scattering...
-
Post-Pyrolytic Carbon as a Phase Change Materials (PCMs) Carrier for Application in Building Materials
PublikacjaThis article covers new application for char as a carrier of phase-change materials (PCM) that could be used as an additive to building materials. Being composed of bio-char and PCM, the granulate successfully competes with more expensive commercial materials of this type, such as Micronal® PCM. As a PCM carrier, char that was obtained from the pyrolysis of chestnut fruit (Aesculus hippocastanum) with different absorbances of the...
-
Reliable renewable energy – application of electrochemical capacitors for electrical energy storage
PublikacjaThis paper presents electrical energy storage devices such as electrochemical capacitors, their principle of operation and electrode materials most commonly used in their manufacturing technology. Moreover, our research on development of new nanocomposite materials based on multi-walled carbon nanotubes and conducting polymer is shown. Additionally, the possibility and advantages of application of supercapacitors for accumulation...
-
Effects of Bromine Doping on the Structural Properties and Band Gap of CH3NH3Pb(I1–xBrx)3 Perovskite
PublikacjaAn experimental and theoretical study is reported to investigate the influence of bromine doping on CH3NH3Pb(I1−xBrx)3 perovskite for Br compositions ranging from x = 0 to x = 0.1, in which the material remains in the tetragonal phase. The experimental band gap is deduced from UV−vis absorption spectroscopy and displays a linear behavior as a function of bromine concentration. Density functional theory calculations are performed...
-
An effective method for studying intermolecular interactions in binary liquids with hydrogen bonds: FTIR spectra and ab initio calculations in the N-methylformamide - methanol system
PublikacjaMolecular complexes in methanol (MeOH)−N-methylformamide (NMF) mixtures were studied based on their FTIR-ATR spectra, to which two methods of analysis were applied: factor analysis and a quantitative version of the difference-spectra method. The mean composition of a complex between NMF and MeOH molecules over the whole range of mixture compositions was determined. Absorbing species differentiated with regard to the interaction...
-
Nonlinearity shaping in nanostructured glass-diamond hybrid materials for optical fiber preforms
PublikacjaNanodiamond integration with optical fibers has proved a compelling methodology for magneto-optics. We reveal that the applicability of nanodiamonds in nonlinear optics goes beyond the previous demonstrations of frequency converters. Instead, we exploit the recently reported volumetric integration of nanodiamonds along the optical fiber core and show that the nonlinear response of glasses can be manipulated by nanodiamonds. By...
-
Ab initio elasticity of chalcopyrites
Publikacja -
Thermodynamic analysis of the Compressed Air Energy Storage system coupled with the Underground Thermal Energy Storage
PublikacjaImprovement of flexibility is one of the key challenges for the transformation of the Polish Power System aiming at a high share of renewable energy in electricity generation. Flexible and dispatchable power plants will contribute to this ongoing transformation process as they compensate for fluctuations in electricity generation from renewable energy sources such as wind and photovoltaics. In this context, CAES storage tanks are...
-
Deep insight into the pore size distribution of N-doped porous carbon materials on electrochemical energy storage and CO2 sorption
Publikacja -
Nanostructured biocatalysis for biotechnological applications
PublikacjaThe purpose immobilization process is to enhance the performance of an enzyme for commercial processes. A large number of structures have been reported in the literature to boost the effectiveness of immobilized enzymes. The nanomaterials have the optimal properties for equilibrating key parameters that govern the performance of biocatalysts, such as high enzyme loading ability, specific surface area, and mass transfer resistance....
-
GRAPHENE-BASED SUPERCAPACITORS APPLICATION FOR ENERGY STORAGE
PublikacjaRecent advances in graphene-based supercapacitor technology for energy storage application were summarized. The comparison of different types of electrode materials in such supercapacitors was performed. The supercapacitors with graphene-based electrodes exhibit outstanding performance: high charge-discharge rate, high power density, high energy density and long cycle-life, what makes them suitable for various applications, e.g....
-
The optical properties and band gap energy of nanocrystalline La0.4Sr0.6TiO3 thin films
PublikacjaW pracy zbadano wpływ mikrostruktury na właściwości optyczne La0.4Sr0.6TiO3 przygotowanego w postaci cienkiego filmu. Gęsty film o grubości 200nm i wielkości krystalitów 14-30nm został przygotowany na szafirze.
-
Charge distribution and magnetic interactions in PrBa2Cu3O7 with substitutional defects and oxygen disorder: the ab initio approach
PublikacjaW artykule zaprezentowano rezultaty kwantowomechanicznych obliczeń ''ab initio: struktury elektronowej układu PrBa2Cu3O7 zawierającego defekty substytucyjne (Pr_Ba) w podsieci barowo-tlenowej oraz wykazującego zaburzoną stechiometrię tlenową (O5). Badane defekty są odpowiedzialne za redystrybucję ładunku w układzie. Defekty Pr_Ba generują silnie zlokalizowane momenty magnetyczne, które oddziałują głównie na płaszczyzny miedziowo-tlenowe.
-
Analytical Methods for Causality Evaluation of Photonic Materials
PublikacjaWe comprehensively review several general methods and analytical tools used for causality evaluation of photonic materials. Our objective is to call to mind and then formulate, on a mathematically rigorous basis, a set of theorems which can answer the question whether a considered material model is causal or not. For this purpose, a set of various distributional theorems presented in literature is collected as the distributional...
-
Ab-initio study of electrical and optical properties of allylamine
PublikacjaThe Density functional theory is one of most promising methodology in fast and accurate calculations of electrical and optical properties from the atomic basis. In this paper, we calculate electrical and optical properties of allylamine (2-propen 1- amine) in terms of accuracy and speed of calculations obtained by selection of DFT-1/2 method with ultrasoft Vanderbilt pseudopotentials. Comparison of density of states between...
-
Ab-initio study of electrical and optical properties of allylamine
PublikacjaThe Density functional theory is one of most promising methodology in fast and accurate calculations of electrical and optical properties from the atomic basis. In this paper, we calculate electrical and optical properties of allylamine (2-propen 1- amine) in terms of accuracy and speed of calculations obtained by selection of DFT-1/2 method with ultrasoft Vanderbilt pseudopotentials. Comparison of density of states between molecule...
-
Nonradiative long range energy transfer in donor-acceptor systems with excluded volume
PublikacjaW pracy analizowano bezpromienisty długozasięgowy transfer energii w układach donor-akceptor z uwzględnieniem objętości wyłączonej. Stwierdzono, że zanik fluorescencji pierwotnie wzbudzonych donorów jest wolniejszy, jeżeli uwzględnia się objętość wyłączoną. Ten efekt jest znacznie wzmocniony, gdy akceptory znajdują się w pewnej objętości niedostępnej dla donorów. Analizę numeryczną przeprowadzono stosując metodę symulacji Monte...
-
Possibilities and benefits of a new method of modifying conventional building materials with phase-change materials (PCMs)
PublikacjaThe paper presents a current study devoted to the optimization of the amount of PCM present within traditional building materials, utilized in this case in hollow-brick walls. Authors focus on proposing an alternative to typical direct addition of PCM to existing building materials: introducing two- and three-component mixtures, based on a porous PCM carrier, which in this case was construction aggregate. Preliminary studies of...
-
Heat transfer enhancement of modular thermal energy storage unit for reversible heat pump cooperation
PublikacjaThe following article presents experimental comparison research on a hexagonal shelland-tube latent thermal energy storage (TES). Such shape of a shell was deliberately chosen instead of a cylindrical one due to its high modularity and with intent for future applications in automobiles (EV and PHEV) air conditioning systems (HVAC). Two geometries of helical coils, acting as tubes, were studied in this article. One was a simple...
-
Shape Memory Materials from Rubbers
PublikacjaSmart materials are much discussed in the current research scenario. The shape memory effect is one of the most fascinating occurrences in smart materials, both in terms of the phenomenon and its applications. Many metal alloys and polymers exhibit the shape memory effect (SME). Shape memory properties of elastomers, such as rubbers, polyurethanes, and other elastomers, are discussed in depth in this paper. The theory, factors...