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Search results for: WIDEBAND COMMUNICATIONS
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Voice Multilateration System
PublicationThis paper presents an innovative method of locating airplanes, which uses only voice communication between an air traffic controller and the pilot of an aircraft. The proposed method is described in detail along with its practical implementation in the form of a technology demonstrator (proof of concept), included in the voice communication system (VCS). A complete analysis of the performance of the developed method is presented,...
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Pitting corrosion in steel and electrochemical noise intensity
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Determination of electrode impedance by means of exponential chirp signal
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The time dependence of pit creation impedance spectra
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Facile synthetic route to selectively protected spermidine homologues
PublicationW wyniku opracowanej procedury otrzymano kilka selektywnie chronionych homologów spermidyny. Reakcja cyjanoetylowania monochronionych diamin pozwoliła na otrzymanie nitryli, które przekształcano w amidy pierwszorzędowe. Degradacja Hofmanna amidów doprowadziła do otrzymania finalnych związków.
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Novel calix[4]resorcinarenes with side azobenzo-15-crown-5 residues
PublicationZsyntezowano nowe kaliks[4]rezorcareny z dwoma lub czteroma resztami azobenzo-15-korony-5 w dowolnym pierścieniu. Związki te otrzymano w reakcji kondensacji rezorcynolu z odpowiednimi aldehydami (acetalami).
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Tmscl as a rate accelerating additive in acylations of amines with 5-(α-amino- α'-hydroxy)methylene meldrum's acids
PublicationAspects are presented of the acylation of amines, alcohols and thiols with 5-(α-amino- α'-hydroxy)methylene Meldrum's acids. We placed special emphasis on the acylation reaction of secondary amines with 5-(α-amino- α'-hydroxy)methylene Meldrum's acids, which, due to their basicity, caused problems concerning salt formation with a Meldrum acid derivative. We found that secondary amines, which react at the slowest rate and with a...
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A new method for preparation of rutile phase titania photoactive under visible light
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A general approach towards carbonization of plastic waste into a well-designed 3D porous carbon framework for super lithium-ion batteries
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Porous nanopeapod Pd catalyst with excellent stability and efficiency
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A graphene-based nanostructure with expanded ion transport channels for high rate Li-ion batteries
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A sumanene-containing magnetic nanoadsorbent for the removal of caesium salts from aqueous solutions
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Disaggregation of a sumanene-containing fluorescent probe towards highly sensitive and specific detection of caesium cations
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Recent developments in the synthesis and applications of graphene-family materials functionalized with cyclodextrins
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Infrared response of multiwalled boron nitride nanotubes
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Visible light-induced photocatalytic reaction of gold-modified titanium(IV) oxide particles: action spectrum analysis
PublicationAnalizy spektrum działania wykazały, ze wzbudzenie powierzchniowego plazmonu złota inicjuje utlenianie 2-propanolu w świetle widzialnym w napowietrzonej zawiesinie tlenku(IV) tytanu zmodyfikowanego zlotem. Badania przeprowadzone z użyciem światła polichromatycznego wykazały, ze szybkość reakcji foto-utleniania zależy od właściwości tlenku(IV) tytanu, takich jak rozmiar ziaren, pola powierzchni właściwej, formy krystalicznej (anataz...
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Magnesium porphyrazine with peripheral methyl (3,5-dibromophenylmethyl)amino groups – synthesis and optical properties
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Synthesis of Novel Polycationic Quaternary Di- and Trispirocyclic Benzenes
PublicationTreatment of hexakis(bromomethyl)benzene with a cyclic amine {morpholine, 1-methylpiperazine, 1-(2-hydroxyethyl)piperazine, isonipecotamide, 4-hydroxypiperidine, 4-[3-(4-piperidyl)propyl]-1-piperidineethanol} gave a range of di- and trispirocyclic ammonium salts in satisfactory yields (22-62%). Presumably, the electrostatic and repulsion forces play an important role in their formation. The structure in soln. and the protonation...
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A Convenient Synthesis of Monocationic 1-[(Cyclic amidino)methyl]thymines
Publication1-[(Cyclic amidino)methyl]thymines have been conveniently synthesized from thymine in a three-step procedure via 1-cyanomethyl- and 1-[(thiocarbamoyl) methyl]thymines. The above synthetic intermediates were obtained in good yields by improved methods.
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Preparation of 1-[Ω-(1,4,5,6-Tetrahydropyrimidin-2-yl)alkyl]thymines
PublicationOne-stage prepn. of the hydrochloride salts of 1-[ω-(1,4,5,6-tetrahydropyrimidin-2-yl)alkyl]-thymines, e.g. I, from 1-(ω-cyanoalkyl)thymines and a 1:1-mixt. of 1,3-diaminopropane and ethanol satd. with hydrogen sulfide is described. 1-(2-Cyanoethyl)-thymine gave a facile reversal of the Michael reaction to thymine under the conditions used. The reaction of 1,3-bis(3-cyanobenzyl)thymine with the above reagent produced 1,3-bis[3-(1,4,5,6-tetrahydropyrimidin-2-yl)benzyl]thymine.
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4-(Cyclic-amidino)phenols. Preparation and Use in a Diamidine Synthesis
PublicationThe Pinner synthesis was applied to the prepn. of phenols 4-substituted with cyclic amidines in high yields from readily available 4-HOC6H4C(OMe):NH.HCl and aliph. diamines. An alternative attempt was made to convert 4-HOC6H4CSNH2 to 4-(1,4,5,6-tetrahydro-5-hydroxy-2-pyrimidinyl)phenol. A procedure for the prepn. of 3,6-bis(4-hydroxyphenyl)-1,2,4,5-tetrazine is reported. The syntheses of 2,4-bis[4-(4,5-dihydro-1H-imidazol-2-yl)phenoxy]pyrimidine...
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Methods for the synthesis of xanthine-derived polycyclic fused systems
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Mesenchymal stem cells transfer mitochondria to allogeneic Tregs in an HLA-dependent manner improving their immunosuppressive activity
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Distinguishing between polymorphic forms of linezolid by solid-phase electronic and vibrational circular dichroism
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Molecular insights into receptor binding energetics and neutralization of SARS-CoV-2 variants
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The comparative study of different methods of spectral analysis of electrochemical oscillations
PublicationOscylacje elektrochemiczne często połączone są z roztwarzaniem metali. One często wykazują niestacjonarny charakter. W związku z czym wydaje się konieczne wykonanie analizy w równoczesnej dziedzinie czasu i częstotliwości. Zaprezentowano porównanie trzech nowych metod: STFT, transformacji falkowej i rozkładu Wigner-Ville´a. Zalety tych metod zostały wypunktowane oraz wykazane zostały różnice pomiędzy analizą Fourierowską i technikami...
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Pitting corrosion in steel and electrochemical noise intensity
PublicationPrzedstawiono analizę szumu elektrochemicznego, rejestrowanego w obecności korozji wżerowej. Stwierdzono korelację pomiędzy intensywnością szumu a ubytkiem mas elektrod stalowych. Rejestry szumowe rozłożone zostały na składowe częstotliwościowe za pomocą przekształcenia falkowego. Dla pewnych składowych stwierdzono silniejszą korelację z ubytkiem mas korodujących elektrod. Pasmo częstotliwościowe powyższych składowych odpowiada...
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Electrochemical formation of the adduct between antitumor agent C_1311 and DNA nucleoside dG. 75.
PublicationPrzyjmuje się, że metaboliczna aktywacja przeciwnowotworowej pochodnej C_1311 jest procesem koniecznym dla jej aktywności przeciwnowotworowej. Wykazano wcześniej, że taka aktywacja prowadzi do kowalencyjnego wiązania się leku z DNA w komórce nowotworowej. Aby zbadać molekularny mechanizm powyższej reakcji metabolicznej przeprowadzono badania elektrochemicznego utleniania pochodnej C_1311. Wykazano w pracy, że dwa produkty elektrochemicznego...
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Cubane Like Structure of a Silanethiol Primary Amine Assembly a Novel, Unusual Hydrogen Bond Pattern.
PublicationMetodą rentgenowskiej analizy strukturalnej wyznaczono struktury krystaliczne i cząsteczkowe trzech soli amoniowych: (t-BuO)3SiS(-)H3N(+)Bu-t, (i-PrO)3SiS(-)H3N(+)Bu-t i (t-BuO)3SiS(-)H3N(+)(CH2)2CH(CH3)2. Wszystkie trzy związki w ciele stałym tworzą tetramery w których atomy S i N wyznaczają w przybliżeniu naroża sześcianu. Trwałość tych agregatów, oprócz sił elektrostatycznego przyciągania, zapewnia sieć wiązań wodorowych N-H
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Realistic noise-tolerant randomness amplification using finite number of devices
PublicationRandomness is a fundamental concept, with implications from security of modern data systems, to fundamental laws of nature and even the philosophy of science. Randomness is called certified if it describes events that cannot be pre-determined by an external adversary. It is known that weak certified randomness can be amplified to nearly ideal randomness using quantum-mechanical systems. However, so far, it was unclear whether randomness amplification...
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Quantum mechanical which-way experiment with an internal degree of freedom
PublicationFor a particle travelling through an interferometer, the trade-off between the available which-way information and the interference visibility provides a lucid manifestation of the quantum mechanical wave-particle duality. Here we analyse this relation for a particle possessing an internal degree of freedom such as spin. We quantify the trade-off with a general inequality that paints an unexpectedly intricate picture of wave-particle...
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Polynomial analysis as a new way of describing dynamic impedance spectra – Differential and relative impedance spectra
PublicationModel measurements of an equivalent electrical system were carried out using the technique of Dynamic Electrochemical Impedance Spectroscopy. The measurement took the form of potentiodynamic changes imposed on the tested system. Using the possibility of continuous impedance measurements, an attempt was made to develop an original and innovative method of analyzing impedance spectrograms, which is termed polynomial analysis. As...
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Context dependent effects of ascorbic acid treatment in TET2 mutant myeloid neoplasia
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Pd-catalysed general access to 7-membered N/O-heterocyclic compounds as potential agents against inflammation
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New type of repeated Si–C-podand catalysts for solid–liquid phase transfer reactions
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Microstructural evolution of 6061 aluminium alloy subjected to static and dynamic compression at low temperature
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Piezoresistive properties of cement composites with expanded graphite
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Flame retardant effect and mechanism of nanosized NiO as synergist in PLA/APP/CSi-MCA composites
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Fe-promoted CuO/CeO2 catalyst
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Surface properties of wustite based iron-cobalt catalysts for ammonia synthesis reaction
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Resonance-Raman spectro-electrochemistry of intermediates in molecular artificial photosynthesis of bimetallic complexes
PublicationThe sequential order of photoinduced charge transfer processes and accompanying structure changes were analyzed by UV-vis and resonance-Raman spectroscopy of intermediates of a Ru(II) based photocatalytic hydrogen evolving system obtained by electrochemical reduction.
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Facile preparation of extremely photoactive boron-doped TiO2 nanotubes arrays
PublicationDoping of TiO2 nanotube arrays with boron was realized via electrochemical treatment of as-anodized titania immersed in electrolyte containing boric acid. The photoactivity of doped and pure titania was examined by means of photoelectrochemical and photocatalytic response under UV-vis irradiation. The results showed that photocurrent density of B-TNTs is remarkably higher (7.5 times) than density of pure TiO2 nanotube arrays. Furthermore,...
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Heterogeneous distribution of surface electrochemical activity in polycrystalline highly boron-doped diamond electrodes under deep anodic polarization
PublicationThe surface homogeneity of boron-doped diamond electrodes is variable and depends on anodic polarization conditions. The differentiation factor is the gradual and localized change in surface termination. A series of measurements under different polarization conditions was performed in order to investigate the scale of this effect. Nanoscale impedance microscopy (NIM) revealed large variation of surface resistance in individual...
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Powerful connection of laccase and carbon nanotubes: Material for mediator-free electron transport on the enzymatic cathode of the biobattery
PublicationOpisany został sposób wytwarzania koniugatów lakaza - jednościenne nanorurki węglowe i ich zastosowanie jako materiałów modyfikujacych katodę w hybrydowym bioogniwie paliwowym z cynkową anodą. Nanorurki węglowe z przyłączonymi grupami aminoetylowymi stanowiły materiał wyjściowy do chemicznego związania lakazy na ich powierzchni. Otrzymany materiał wykazywał wysoką aktywność bioelektrokatalityczną i jest obiecujacym materiałem do...
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Fully enzymatic mediatorless fuel cell with efficient naphthylated carbon nanotube-laccase composite cathodes
PublicationAn efficient, mediator-free enzymatic glucose/O2 biofuel cell with an oxygen intensive anode based on glucose dehydrogenase is presented. In the device,the power of the biofuel cell and electrode potentials of each of the enzymatic electrodes were monitored in parallel under the biofuel cell working conditions. The carbon nanotube composite biocathode demonstrates an almost constant electrode potential vs. saturated calomel electrode...
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Synthesis and reactivity of O-acyl selenophosphates
PublicationThe synthesis of several new O-acyl selenophosphates were investigated. The stability and reactivity of the products were studied and related to their structure.
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Generic emergence of classical features in quantum Darwinism
PublicationQuantum Darwinism posits that only specific information about a quantum system that is redundantly proliferated to many parts of its environment becomes accessible and objective, leading to the emergence of classical reality. However, it is not clear under what conditions this mechanism holds true. Here we prove that the emergence of classical features along the lines of quantum Darwinism is a general feature of any quantum dynamics:...
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A large family of filled skutterudites stabilized by electron count
PublicationThe Zintl concept is important in solid-state chemistry to explain how some compounds that combine electropositive and main group elements can be stable at formulas that at their simplest level do not make any sense. The electronegative elements in such compounds form a polyatomic electron-accepting molecule inside the solid, a ‘polyanion’, that fills its available energy states with electrons from the electropositive elements...
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TMSCL as a rate accelerating additive in acylations of amines with 5-(α- amino-α'-hydroxy)methylene meldrum's acids
PublicationAspects are presented of the acylation of amines, alcohols and thiols with 5-(α-amino- α'-hydroxy)methylene Meldrum's acids. We placed special emphasis on the acylation reaction of secondary amines with 5-(α-amino- α'-hydroxy)methylene Meldrum's acids, which, due to their basicity, caused problems concerning salt formation with a Meldrum acid derivative. We found that secondary amines, which react at the slowest rate and with a...
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One-step formation of n-alkenyl-malonamides and n-alkenyl-thiomalonamides from carbamoyl meldrum's acids.
PublicationA one-pot synthesis for the preparation of N-alkenyl-malonamides and N-alkenyl-thiomalonamides was developed. 5-[Hydroxy/mercapto(aryl/alkylamino)methylene]-2,2-dimethyl-1,3-dioxane-4,6-dione act as a source of ketenes that react with the tautomeric form of alkyl-(2-phenyl-propylidene)-amines. A possible [2+2] or [4+2] cycloaddition product of ketene to imines was not observed.