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Wyniki wyszukiwania dla: ab initio quantum chemistry methods
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Dissociative ionization dynamics of dielectric gas C3F7CN
PublikacjaFluoronitrile C3F7CN is a promising candidate for the replacement of SF6 dielectric gas in high-voltage insulation. We present a combined experimental and theoretical study on its ionization dynamics probed in the 0-100 eV energy range. We exploited the total ion collection technique to determine the absolute ionization cross section, mass spectrometry to determine the fragment branching ratios and ab initio nonadiabatic molecular...
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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...
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Andrzej Okuniewski dr inż.
OsobyWykształcenie 2010-2014: Katedra Chemii Nieorganicznej, Wydział Chemiczny, Politechnika Gdańskadoktor nauk chemicznych (nauki chemiczne – chemia, chemia nieorganiczna) 2009-2010: Wydział Chemiczny, Politechnika Gdańskamagister chemii (chemia stosowana) 2005-2009: Wydział Chemiczny, Politechnika Gdańskainżynier chemik (chemia stosowana) 2002-2005: II Liceum Ogólnokształcące im. Władysława Pniewskiego w Gdańskuprofil biologiczno-chemiczno-fizyczny...
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Electron attachment to representative cations composing ionic liquids
PublikacjaUsing ab initio electronic structure methods with flexible atomic orbital basis sets, we investigated the electronic structure and stability of reduction products of selected representative cations (C+) constituting ionic liquids. We found that an electron attachment to such cations leads to the neutral radicals, whereas a subsequent attachment of another (i.e., excess) electron leads to adiabatically stable anions only in two...
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Evaluation of the Greenness of Analytical Procedures
PublikacjaThis contributions introduces the need to develop the methods to evaluate analytical procedures in the light of green analytical chemistry. Green chemistry metrics are not applicable in analytical chemistry because they refer to the mass of product and no product with mass is generated during analytical determination. Analytical greenness evaluations are based on scoring - such as NEMI or Eco-scale or comparative analysis as it...
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Objectivity in the non-Markovian spin-boson model
PublikacjaObjectivity constitutes one of the main features of the macroscopic classical world. An important aspect of the quantum-to-classical transition issue is to explain how such a property arises from the microscopic quantum theory. Recently, within the framework of open quantum systems, there has been proposed such a mechanism in terms of the so-called spectrum broadcast structures. These are multipartite quantum states of the system...
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The influence of intermolecular correlations on the infrared spectrum of liquid dimethyl sulfoxide
PublikacjaDimethyl sulfoxide (DMSO) is routinely applied as an excellent, water-miscible solvent and chemical reagent. Some of the most important data concerning its liquid structure were obtained using infrared (IR) spectroscopy. However, the actual extent of intermolecular correlations that connect the isolated monomer spectrum to the IR response of the bulk liquid is poorly studied thus far. Using ab initio molecular dynamics (AIMD) simulations,...
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Hydration of simple amides. FTIR spectra of HDO and theoretical studies
PublikacjaZastosowano metodę ważonych widm różnicowych do opisu hydratacji amidów w roztworach wodnych: formamidu, N-metyloformamidu, N,N-dimetyloformaidu, acetamidu, N-metyloacetamidu, N,N-dimetyloacetamidu. Narzędziem wspomagającym interpretację wyników eksperymentalnych są struktury agregatów solwatacyjnych wokół cząsteczki substancji rozpuszczonej uzyskane na podstawie obliczeń teoretycznych metodą ab initio z korelacją elektronową...
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Configurations of H 3 + (H2)n clusters and their energies
PublikacjaThe H-3(+) ion plays an important role in low temperature astrophysical and laboratory plasmas. It is considered as the initiator of many ion-molecule chemistries. Also its clusters with H-2 are quite interesting. We study configurations of the H-3(+)(H-2)(n) clusters for n = 1 up to n = 12 as a simple test system. Total energies for these structures, with zero point vibration corrections have been calculated. Stabilization energies...
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Photoelectron spectroscopy of a series of acetate and propionate esters
PublikacjaThe electronic state and photoionization spectroscopy of a series of acetate esters: methyl acetate, isopropyl acetate, butyl acetate and pentyl acetate as well as two propionates: methyl propionate and ethyl propionate, have been determined using vacuum-ultraviolet photoelectron spectroscopy. These experimental investigations are complemented by ab initio calculations. The measured first adiabatic and vertical ionization energies...
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Low-Barrier Hydrogen Bond Determines Target-Binding Affinity and Specificity of the Antitubercular Drug Bedaquiline
PublikacjaThe role of short strong hydrogen bonds (SSHB) in ligand-target binding remains largely unexplored, thereby hin- dering a potentially important avenue in the rational drug de- sign. Here, we investigate the interaction between bedaquiline (Bq), a potent anti-tuberculosis drug, and the mycobacterial ATP synthase, to unravel the role of a specific hydrogen bond to a conserved acidic residue in the target affinity and specificity....
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How can analysts use multicriteria decision analysis?
PublikacjaProper decision making in multifacitated situation is very challenging task. It is especially difficult if there are many alternatives and criteria that are often contradictory. Analytical chemistry and related sciences involve many situations where decisions on complex problems are made. The support tools may be the use of MCDA (Multi-criteria Decision Analysis) algorithms. They formalize the decision process, make it transparent...
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Impact of dyes isomerization effect on the charge transfer phenomenon occurring on the dye/nanosemiconductor interface
PublikacjaThe present work aimed to find the answer how does the isomerization of the Ru based dyes affect the overall photon-to-current efficiency of the DSSCs and to explain the charge transfer phenomenon occurring on the dye/ nanosemiconductor interface. Therefore, electronic and optical properties of three bipyridine derivatives anchored on the TiO2 electrode were investigated by computational simulations based on quantum chemistry codes...
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Enhanced photocatalytic properties of lanthanide-TiO2 nanotubes: An experimental and theoretical study
PublikacjaA series of Er-, Yb-, Ho-, Tb-, Gd-, Pr-TiO2 nanotubes (RE-NTs) was prepared via an electrochemical method. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis absorption, scanning electron microscopy (SEM) and luminescent spectroscopy. The experiments demonstrated that toluene in the gas phase was successfully degraded under visible light (LEDs λmax = 465...
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The electrical properties mesurements of DIR-SOFC with Ce0.8Fe0.2O2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with Ce0.8Fe0.1O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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The electrical properties mesurements of DIR-SOFC with Ce0.8Co0.2O2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with Ce0.8Co0.1O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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The electrical properties mesurements of DIR-SOFC with Ce0.8Mn0.2O2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with Ce0.8Mn0.1O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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The electrical properties mesurements of DIR-SOFC with Ce0.8Ni0.2O2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with Ce0.8Ni0.1O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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The electrical properties mesurements of DIR-SOFC with CeO2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with CeO2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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The electrical properties mesurements of DIR-SOFC with Ce0.8Cu0.2O2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with Ce0.8Cu0.1O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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Autocorrelation function for the chosen effective potential of the diatomic silver anion
Dane BadawczeThe process of a two-channel decay of the diatomic silver anion (Ag2-), namely the spontaneous electron ejection giving Ag2 + e- and the dissociation leading to Ag- + Ag is theoretically studied. The ground state potential energy curves (PECs) of the neutral silver dimer and anionic silver diatomic molecule are calculated using the single reference...
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Nanoparticles: Synthesis, characteristics, and applications in analytical and other sciences
PublikacjaNanoparticles (NPs) are widely employed in different research areas, ranging from analytical chemistry and environmental science to medicine, the agriculture and pharmaceutical industry. This is mainly due to the unique characteristics of NPs and the novelty they introduce in such applications. In analytical chemistry, the role of NPs can differ depending on the nature of the steps involved in analytical process. NPs are probably...
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How acidic amino acid residues facilitate DNA target site selection
PublikacjaDespite the negative charge of the DNA backbone, acidic residues (Asp/Glu) commonly participate in the base readout, with a strong preference for cytosine. In fact, in the solved DNA/protein structures, cytosine is recognized almost exclusively by Asp/Glu through a direct hydrogen bond, while at the same time, adenine, regardless of its amino group, shows no propensity for Asp/Glu. Here, we analyzed the contribution of Asp/Glu...
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Atomic-Scale Finite-Element Modeling of Elastic Mechanical Anisotropy in Finite-Sized Strained Phosphorene Nanoribbons
PublikacjaNanoribbons are crucial nanostructures due to their superior mechanical and electrical properties. This paper is devoted to hybrid studies of the elastic mechanical anisotropy of phosphorene nanoribbons whose edges connect the terminals of devices such as bridges. Fundamental mechanical properties, including Young’s modulus, Poisson’s ratio, and density, were estimated from first-principles calculations for 1-layer, 3-layer, and...
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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...
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Structure and properties of liquid Al–Cu alloys: Empirical potentials compared
PublikacjaWe report on the structure and mass transport properties of liquid Al–Cu alloys predicted by two recently-developed empirical many-body potentials: MEAM (Jelinek et al., 2012) and EAM-ADP (Apostol and Mishin, 2011), and by the well-known Gupta potential. Total and partial pair correlation functions, angular distribution functions, densities, coordination numbers and self-diffusion coefficients are compared with published experimental...
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Structure and Molecular Dynamics in Renewable Polyamides from Dideoxy-Diamino Isohexide
PublikacjaThe chemical structure, the conformation, andthe flexibility of the polymer chain fragments present in thepolyamides synthesized from 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydrosorbitol, 1,4-diaminobutane, and either sebacic orbrassylic acid have been studied by liquid-state 2D NMRspectroscopy viz. correlation spectra (COSY) and heteronuclearmultiple-bond correlation spectra (gHMBC), by 13Ccross-polarization/magic-angle spinning...
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The changes of outlet gases concentrations from SOFC with Ce(Pr,Sm)O2-s layers
Dane BadawczeThe dataset includes The changes of outlet gases concentrations from SOFC with Ce(Pr,Sm)O2-s layers. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding.
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Coacervative extraction as a green technique for sample preparation for the analysis of organic compounds
PublikacjaOne of the present trends in analytical chemistry is miniaturization, which is one of the methods of green analytical chemistry application. A particular emphasis is placed on the elimination of the use of large amounts of organic solvents which are toxic and harmful to the environment, maintaining high efficiency of the extraction process, high recovery values and low values of quantification (LOQ) and detection (LOD) limits....
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Stable Field Electron Emission and Plasma Illumination from Boron and Nitrogen Co‐Doped Edge‐Rich Diamond‐Enhanced Carbon Nanowalls
PublikacjaSuperior field electron emission (FEE) characteristics are achieved in edge-rich diamond-enhanced carbon nanowalls (D-ECNWs) grown in a single-step chemical vapor deposition process co-doped with boron and nitrogen. The structure consists of sharp, highly conductive graphene edges supplied by a solid, diamond-rich bottom. The Raman and transmission electron microscopy studies reveal a hybrid nature of sp3-diamond and sp2-graphene...
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Unique agreement of experimental and computational infrared spectroscopy: a case study of lithium bromide solvation in an important electrochemical solvent
PublikacjaInfrared (IR) spectroscopy is a widely used and invaluable tool in the studies of solvation phenomena in electrolyte solutions. Using state-of-the-art chemometric analysis of a spectral series measured in a concentration-dependent manner, the spectrum of the solute-affected solvent can be extracted, providing a detailed view of the structural and energetic states of the solvent molecules influenced by the solute. Concurrently,...
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The Role of Electron Transfer in the Fragmentation of Phenyl and Cyclohexyl Boronic Acids
PublikacjaIn this study, novel measurements of negative ion formation in neutral potassium-neutral boronic acid collisions are reported in electron transfer experiments. The fragmentation pattern of phenylboronic acid is comprehensively investigated for a wide range of collision energies, i.e., from 10 to 1000 eV in the laboratory frame, allowing some of the most relevant dissociation channels to be probed. These studies were performed in...
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The electrical properties mesurements of SOFC with Ce0.9Cu0.1O2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with Ce0.9Cu0.1O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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The electrical properties mesurements of SOFC with Ce0.9Co0.1O2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with Ce0.9Co0.1O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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The electrical properties mesurements of SOFC with Ce0.8Co0.1Cu0.1O2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with Ce0.8Co0.1Cu0.1O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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The electrical properties mesurements of SOFC with Ce0.8Co0.15Cu0.05O2-s functional layer
Dane BadawczeThe dataset includes the electrical properties mesurements of SOFC with Ce0.8Co0.15Cu0.05O2-s layer. Samples were produced using aqueous soft chemistry methods (microemulsion method) and applied in form of a layer onto the anode of the commercial SOFC. The SOFC was working under biogas feeding at 750oC. The layers were sintered at 1100oC.
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Synergy between AgInS2 quantum dots and ZnO nanopyramids for photocatalytic hydrogen evolution and phenol degradation
PublikacjaDespite the unique properties of single semiconductor nanomaterials and quantum dots, poor photocatalytic activity has characterized them and the fabrication of nanocomposites has become necessary to enhance their photocatalytic performance. Thus, AgInS2 quantum dots (AIS QDs, 4.0±1.6 nm), have been successfully prepared and loaded onto ZnO nanopyramids (ZnO NPy). The effect of the nominal amount of AIS QDs decorating ZnO NPy on...
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Coupled cluster and DFT calculations of 14N nuclear quadrupole coupling constants
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Can cooperativity in hydrophobic association be reproduced correctly by implicit solvation models?
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Variational principles for bound states of Schrödinger and Dirac equations allowing the use of discontinuous trial functions
PublikacjaWe present systematic constructions of variational principles for energies of bound states of the Schroedinger and Dirac equations. The principles allow the use of discontinuous trial functions. The method employed is based on a generalized Lagrange procedure. Relationships between our variational principles and those available in the literature are established.
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Electric and magnetic dipole shielding constans for the ground state of the relativistic hydrogen-like atom: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublikacjaStosując rozwinięcie sturmowskie funkcji Greena-Diraca-Coulomba, znaleziono wyrażenie analityczne dla stałych ekranowania elektrycznego i magnetycznego relatywistycznego atomu wodoropodobnego w stanie podstawowym.
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Dipole-bound anions supported by charge-transfer interaction: Anionic states of HnF3?nN ? BH3 and H3N ? BHnF3?n (n = 0, 1, 2, 3)
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Toward the preparation of the HAuF6 , HAu2 F11 , and HAu3 F16 superacids: Theoretical study
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Low-energy (0.1 eV) electron attachment S?S bond cleavage assisted by Coulomb stabilization
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Multi-state multi-reference Møller-Plesset second-order perturbation theory for molecular calculations
PublikacjaThis work presents multi‐state multi‐reference Møller–Plesset second‐order perturbation theory as a variant of multi‐reference perturbation theory to treat electron correlation in molecules. An effective Hamiltonian is constructed from the first‐order wave operator to treat several strongly interacting electronic states simultaneously. The wave operator is obtained by solving the generalized Bloch equation within the first‐order...
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Large-scale DFT calculations in implicit solvent-A case study on the T4 lysozyme L99A/M102Q protein
PublikacjaW ostatnich latach zaproponowano szereg modeli typu implicit solvent, ktore bazują na bezpośrednim rozwiązaniu niejednorodnego równania Poissona w przestrzeni rzeczywistej. Modele te charakteryzują się elegancją, ponieważ wnęka, w której umieszczona jest molekuła substancji rozpuszczanej zdefiniowana jest bezpośrednio w funkcji gęstości elektronowej, a rozkład ładunku jest w sposób samouzgodniony polaryzowany dzięki reakcji dielektryka,...
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ELECTRON ATTACHMENT TO HETEROGENEOUS MOLECULAR CLUSTERS
PublikacjaHeterogeneous clusters are unique model species enabling studies of bulk and surface processes by vacuum restricted methods. This is of particular importance for the reactions of low-energy electrons which have extremely short penetration depth in bulk environments. This contribution overviews our recent experiments with low-energy electrons and clusters prepared by different techniques. First, the deposition of molecules on argon...
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DFT studies of the refractive index of boron-doped diamond
PublikacjaThe density functional theory is one of the optimal solutions in calculation of optical properties of materials on the quantum scale. In this paper, we have investigated the refractive index of a boron-doped diamond structure with the usage of Atomistic Toolkit software from Synopsys. During this study, various methods and pseudopotentials were checked to obtain an optimal performanceaccuracy method for calculation of such materials....
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Molecular Design Using Selected Concentration Effects in Optically Activated Fluorescent Matrices
PublikacjaMolecular physics plays a pivotal role in various fields, including medicine, pharmaceuticals, and broader industrial applications. This study aims to enhance the methods for producing specific optically active materials with distinct spectroscopic properties at the molecular level, which are crucial for these sectors, while prioritizing human safety in both production and application. Forensic science, a significant socio-economic...
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Quantum dots in gas sensing a review
PublikacjaAir pollution becomes an increasing problem in the recent years. There is a need to develop more sensitive gas sensors. Much effort has been performed to develop different types of gas sensors, such as electrochemical sensors or polymer sensors. One of the most promising approaches to improve sensors performance is the application of the nanostructures as sensing materials. State of the art of quantum...