Search results for "40"

showing 10 items of 17345 documents

Exotic SiO(2)H(2) Isomers: Theory and Experiment Working in Harmony.

2016

Replacing carbon with silicon can result in dramatic and unanticipated changes in isomeric stability, as the well-studied CO2H2 and the essentially unknown SiO2H2 systems illustrate. Guided by coupled-cluster calculations, three SiO2H2 isomers have been detected and spectroscopically characterized in a molecular beam discharge source using rotational spectroscopy. The cis,trans conformer of dihydroxysilylene HOSiOH, the ground-state isomer, and the high-energy, metastable dioxasilirane c-H2SiO2 are abundantly produced in a dilute SiH4/O2 electrical discharge, enabling precise structural determinations of both by a combination of isotopic measurements and calculated vibrational corrections. …

010304 chemical physicsSiliconChemistrychemistry.chemical_element010402 general chemistry01 natural sciencesDissociation (chemistry)0104 chemical sciencesComputational chemistryMetastability0103 physical sciencesRotational spectrumPhysical chemistryGeneral Materials ScienceElectric dischargeRotational spectroscopyPhysical and Theoretical ChemistryMolecular beamConformational isomerismThe journal of physical chemistry letters
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Infrared Spectroscopy of Disilicon-Carbide, Si2C: The ν3 Fundamental Band

2019

The ν3 antisymmetric stretching mode of disilicon-carbide, Si2C, was studied using a narrow line width infrared quantum cascade laser spectrometer operating at 8.3 μm. The Si2C molecules were produ...

010304 chemical physicsSpectrometerChemistryInfraredAntisymmetric relationInfrared spectroscopy010402 general chemistry01 natural sciencesLine width0104 chemical sciencesCarbidelaw.inventionlaw0103 physical sciencesMoleculePhysical and Theoretical ChemistryAtomic physicsQuantum cascade laserThe Journal of Physical Chemistry A
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Monte Carlo Simulations of Au38(SCH3)24 Nanocluster Using Distance-Based Machine Learning Methods

2020

We present an implementation of distance-based machine learning (ML) methods to create a realistic atomistic interaction potential to be used in Monte Carlo simulations of thermal dynamics of thiol...

010304 chemical physicsbusiness.industryChemistryMonte Carlo methodThermal dynamics010402 general chemistryMachine learningcomputer.software_genre01 natural sciences0104 chemical sciencesInteraction potential0103 physical sciencesCluster (physics)Artificial intelligencePhysical and Theoretical ChemistrybusinesscomputerDistance basedThe Journal of Physical Chemistry A
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A Study of Milk Particles Size Variation with pH Change using Dynamic Light Scattering

2019

A very simple experimental setup for a Dynamic Light Scattering measurement was used to measure the average size of the milk proteins in aqueous suspensions at 20 °C. The PH of the suspensions was adjusted using Calcium lactate, in its most common form of pentahydrate C6H10CaO6•5H2O. The mean size variation of the suspended particles in time has been monitored and reveals a fast increase over a time interval of less than ten of seconds.

010309 opticsMaterials scienceVariation (linguistics)Dynamic light scatteringlcsh:TA1-2040Chemical physics0103 physical sciences02 engineering and technologylcsh:Engineering (General). Civil engineering (General)021001 nanoscience & nanotechnology0210 nano-technology01 natural sciencesMATEC Web of Conferences
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Climatic conditions influence emerging mycotoxin presence in wheat grown in Romania – A 2-year survey

2017

Abstract The correlation between the occurrence of four enniatins (ENA, ENA1, ENB, and ENB1) and beauvericin (BEA) and the weather parameters during anthesis and preharvest period was studied in 97 wheat samples collected in 2014 and 2015 across three counties from central and south Romania (Brasov, Dâmboviţa, and Teleorman). The highest mean values of ENA (16.1 μg kg −1 ) and ENB (147.1 μg kg −1 ) were measured in the samples from Brasov county in the harvest year 2015, whereas for ENA1 and ENB1 the highest means (55.2 μg kg −1 , and 108.0 μg kg −1 , respectively) were noted in samples from Teleorman county in 2014. Statistically significant differences ( P r s  = 0.8745 and r s  = 0.9326;…

010401 analytical chemistry04 agricultural and veterinary sciencesBiology040401 food science01 natural sciencesBeauvericin0104 chemical scienceschemistry.chemical_compound0404 agricultural biotechnologyAnimal sciencechemistryAnthesisPreharvestMycotoxinAgronomy and Crop ScienceCrop Protection
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Luminescent TOP Nanosensors for Simultaneously Measuring Temperature, Oxygen, and pH at a Single Excitation Wavelength

2019

Two nanosensors for simultaneous optical measurements of the bioanalytically and biologically relevant analytes temperature (“T”), oxygen (“O”), and pH (“P”) have been designed. These “TOP” nanosensors are based on 100 nm-sized silica-coated polystyrene nanoparticles (PS-NPs) doped with a near-infrared emissive oxygen- and temperature-sensitive chromium(III) complex ([Cr(ddpd)2][BPh4]3, CrBPh4) and an inert reference dye (Nile Red, NR or 5,10,15,20-tetrakis(pentafluorophenyl) porphyrin, TFPP) and are covalently labeled with pH-sensitive fluorescein isothiocyanate (FITC). These emitters can be excited at the same wavelength and reveal spectrally distinguishable emission bands, allowing for r…

010401 analytical chemistryDopingAnalytical chemistryNile redNanoparticle010402 general chemistry01 natural sciencesPorphyrinFluorescence0104 chemical sciencesAnalytical Chemistrychemistry.chemical_compoundchemistryNanosensorExcited stateLuminescenceAnalytical Chemistry
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The Challenges of Air Protection and Control

2016

010401 analytical chemistryEnvironmental scienceBiochemical engineeringSensitivity (control systems)01 natural sciences0104 chemical sciences
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A New LA ‐ ICP ‐ MS Method for Ti in Quartz: Implications and Application to High Pressure Rutile‐Quartz Veins from the Czech Erzgebirge

2016

Experimental determination of the pressure and temperature controls on Ti solubility in quartz provides a calibration of the Ti-in-quartz (TitaniQ) geothermometer applicable to geological conditions up to ~ 20 kbar. We present a new method for determining 48Ti mass fractions in quartz by LA-ICP-MS at the 1 μg g−1 level, relevant to quartz in HP-LT terranes. We suggest that natural quartz such as the low-CL rims of the Bishop Tuff quartz (determined by EPMA; 41 ± 2 μg g−1 Ti, 2s) is more suitable than NIST reference glasses as a reference material for low Ti mass fractions because matrix effects are limited, Ca isobaric interferences are avoided, and polyatomic interferences at mass 48 are i…

010401 analytical chemistryPolyatomic ionAnalytical chemistrychemistry.chemical_elementMineralogyGeologyElectron microprobe010502 geochemistry & geophysics01 natural sciences0104 chemical scienceschemistryGeochemistry and PetrologyRutileCalibrationIsobaric processMass fractionQuartz0105 earth and related environmental sciencesTitaniumGeostandards and Geoanalytical Research
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Les enjeux de la sécurité des objets connectés et applications de santé

2016

International audience; The challenges of security of connected objects and health applicationsThe market for connected objects and health applications is booming and is expected to be several billion euros in revenue in the coming years. Their development will have a similar impact to what we experienced with the development of internet earlier this century but even more it should disrupt the organization of our health system, profoundly change the management of care and revolutionize prevention, but it could also call into question medical confidentiality and protection of personal data. This article analyses the societal implications of OCS, the need for a dual medical and ethical evalua…

010401 analytical chemistrysécurité020206 networking & telecommunications02 engineering and technologysecurity01 natural sciencesimpact sociétalhealth applications0104 chemical sciences[SPI.AUTO]Engineering Sciences [physics]/Automaticconnected objects[ SPI.AUTO ] Engineering Sciences [physics]/Automatic0202 electrical engineering electronic engineering information engineeringapplication de santé[SDV.IB]Life Sciences [q-bio]/Bioengineering[ SDV.IB ] Life Sciences [q-bio]/Bioengineeringsocietal implicationsobjet connecté
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Sensitive Assays by Nucleophile-Induced Rearrangement of Photoactivated Diarylethenes.

2018

Upon light-induced isomerization, diarylethenes (DAEs) equipped with reactive aldehyde moieties rearrange selectively in the presence of amines, accompanied by decoloration. In a comprehensive study, the probe structure was optimized with regard to its inherent reactivity in the nucleophile-triggered rearrangement reaction. Detailed structure−reactivity relationships could be derived, in particular with regard to the type of integrated (het)aryl moieties as well as the location of the formyl residue, and the probes’ intrinsic reactivity with primary and secondary amines was optimized. Utilizing an ancillary base, the initially formed rearrangement product can engage in a subsequent catalyti…

010402 general chemistry01 natural sciencesBiochemistryAldehydeCatalysischemistry.chemical_compoundPhotochromismColloid and Surface ChemistryNucleophile541 Physikalische ChemieReactivity (chemistry)Rearrangement reactionsensingchemistry.chemical_classification010405 organic chemistryArylGeneral ChemistryphotochromismCombinatorial chemistry0104 chemical sciences540 Chemie und zugeordnete WissenschaftenaminechemistryCatalytic cycleddc:540diaryletheneddc:541547 Organische ChemieIsomerizationddc:547Journal of the American Chemical Society
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