showing 36 of ~574560 from 574555 documents

false

1985

Viscosity measurements were carried out as a function of pressure and temperature with solutions of 8 wt.-% PVC (Mw ≈ 75 000) in ten thermodynamically good solvents by means of a Searle-type viscometer. A rollingxyhball viscometer was used for the investigation of the pure solvents. In all cases the viscosity increases in a more or less exponential manner when the pressure is raised. The viscosity ratio f1000 = η1000 bar/η1bar can be varied by the choice of the solvent from ca. 2 (tetrahydrofuran) to 3,0 (cyclohexanone) at 40°C. For a constant temperature of 40°C, the volumes of activation for the viscous flow of the solutions, V≠, or f1000 exceed that of the pure solvent, by typically 25%.…

chemistry.chemical_classificationRelative viscosityViscometerCyclohexanoneThermodynamicsPolymerSolventViscositychemistry.chemical_compoundchemistryPolymer chemistryOrganic chemistryTetrahydrofuranBar (unit)Die Makromolekulare Chemie

Zentralisatoren in lokal endlichen Gruppen vom Chevalley-Typ

1985

Pure mathematicsGeneral MathematicsMathematicsArchiv der Mathematik

Farbenwandel der Zahnhartgewebe als Zeichen thermischer Sch�digung

1985

Die menschlichen Hartgewebe lassen nach thermischer Schadigung gewisse Ruckschlusse auf Brandparameter zu. Neben morphologischer Destruktion ist an den Zahnhartgeweben ein Farbenwandel zu beobachten. Diese Form der Zustandsanderung von Schmelz, Dentin und Zement ist an 330 menschlichen extrahierten Zahnen unter definierten Zeit-und Temperaturintervallen studiert worden. Die Farbphanomene als Ergebnisse der Gluh- und Aufheizversuche sind mit Hilfe der DIN- und RAL-Farbregister ausgewertet worden. Am leichtesten last sich die Zementfarbe bestimmen, da markierende Belage oder Konkremente fehlen. Auserdem bleibt die Wurzelform relativ lange erhalten, wahrend die Zahnkronen zerfallen konnen. Die…

Gynecologymedicine.medical_specialtybusiness.industryPhilosophymedicineDentistryThermal damageAnatomybusinessPathology and Forensic MedicineZeitschrift f�r Rechtsmedizin

false

1985

A new Continuous Polymer Fractionation method, called CPF, is described. The polymer to be fractionated is dissolved in a solvent/non-solvent mixture, and this solution (feed) is extracted continuously by a second liquid (extracting agent), which contains the same solvent components as the feed. In the case of PVC, the fractionation was carried out with a pulsed counter current extraction apparatus and THF/water was used as solvent/non-solvent mixture. Fractionation is achieved by the fact that the molecules are distributed over the counter current phases according to their chain length; the feed leaves the column as gel and the extracting agent as sol. First some explorative experiments we…

Solventchemistry.chemical_classificationChain lengthChromatographyChemistryExtraction (chemistry)Counter currentMoleculeFractionationPolymerPolymer fractionationDie Makromolekulare Chemie

Atherosclerosis precursors in Finnish children and adolescents. X. Leisure-time physical activity.

1985

As part of the more extensive project concerned with atherosclerosis precursors in Finnish children, this article aims at describing the method developed for epidemiological estimation of habitual physical activity, discussing the reliability and validity of the method and reporting the results of the application of this strategy in the measurement of habitual physical activity among 3 to 18-year-old Finnish boys and girls. The questionnaire for the measurement of physical activity was addressed to the parents of 3- and 6-year-old subjects (younger group) and to the subjects themselves in 9- to 18-year-olds (older group). Using four variables in the younger group and nine variables in the o…

GerontologyMaleRiskmedicine.medical_specialtyAdolescentLeisure timePhysical ExertionPhysical activityCoronary Disease03 medical and health sciences0302 clinical medicineChild DevelopmentLeisure ActivitiesSex FactorsSex factorsInternal consistencyEpidemiologymedicineHumans030212 general & internal medicineChildFinlandEstimationbusiness.industry030229 sport sciencesGeneral MedicineChild developmentChild PreschoolPediatrics Perinatology and Child HealthPhysical therapyLocal environmentFemalebusinessSportsActa paediatrica Scandinavica. Supplement

Insertion des jeunes en 1984

1985

Enquête IVA[SHS.EDU]Humanities and Social Sciences/EducationInsertion des jeunesEmploi des jeunes[SHS.EDU] Humanities and Social Sciences/EducationJeune sans qualificationChômage des jeunesFranceInsertion professionnelle des jeunes

Comprehensive Insect Physiology, Biochemistry and Pharmacology. Edited by G. A. Kerkut and L. I. Gilbert. Pergamon Press, Oxford. 1985. 13 Volumes. 8…

1985

EntomologyInsect ScienceInsect physiologyComputational biologyBiologybiology.organism_classificationInsect Science and Its Application

Phytotoxicity and metabolism of chlortoluron in two wheat varieties

1985

Abstract Varietal susceptibility of winter wheat to chlortoluron, 1-(3-chloro-4-methylphenyl)-3,3 dimethylurea, has been studied in two varieties, Corin (susceptible) and Clement (tolerant). After a 24-hr root absorption of the herbicide, phytotoxicity was estimated from growth measurements. When administered at 12 to 96 μM concentrations, the herbicide reduced the growth of both varieties. A significant selective effect was found at 96 μM. Measurements of chlorophyll fluorescence-induction kinetics allowed to discriminate between the two varieties treated with 12 to 48 μM chlortoluron. The metabolism of chlortoluron was studied following absorption of 24 μM solutions. Both varieties produc…

0106 biological sciences[SDV]Life Sciences [q-bio]Health Toxicology and MutagenesisMetaboliteBiology01 natural scienceschemistry.chemical_compoundPoaceaeCultivarComputingMilieux_MISCELLANEOUS2. Zero hunger04 agricultural and veterinary sciencesGeneral MedicineMetabolismCHLOTOLURONDimethylurea[SDV] Life Sciences [q-bio]chemistryAgronomyChlorophyllChlortoluron040103 agronomy & agriculture0401 agriculture forestry and fisheriesPhytotoxicityAgronomy and Crop Science010606 plant biology & botanyPesticide Biochemistry and Physiology

false

1985

From the break-down in the viscosity and from the increase of the intensity of the scattered light, associated with the entrance into the two-phase region, the pressure dependence of the demixing temperature of solutions of PVC 37 000, PVC 75 000 and PVC 100 000 in phenetole and PVC 75 000 in o-xylene was measured up to 1 000 bar. (The numbers in the codes of the PVC specimens are their approximate molecular weights.) The application of pressure increases the demixing temperatures of PVC in both solvents by about 1 K/100 bar. For a qualitative forecast of the pressure effects, the solubility parameter theory in combination with the corresponding states principle, and an empirical correlatio…

SolventHildebrand solubility parameterViscosityChemistryPolymer chemistryMelting pointOrganic chemistryThermodynamicsFractionationSolubilityIntensity (heat transfer)Bar (unit)Die Makromolekulare Chemie

Energy-weighted M1 sum rule with explicit δ degrees of freedom

1985

Abstract The influence of Δ degrees of freedom on the energy-weighted M1 sum rule is investigated and applied to 2 H and 4 He. Using π- and ρ-exchange potentials a reduction of the potential contribution of the order of 50% is obtained. The absolute value of the sum rule is strongly dependent on the short-range behaviour of the nuclear wave function. Furthermore, the contribution of c.m. effects is evaluated and found to be of the order of 5–10%.

Reduction (complexity)PhysicsNuclear and High Energy PhysicsLinearity of differentiationRule of sumDegrees of freedomMathematical analysisOrder (group theory)Sum rule in quantum mechanicsAbsolute value (algebra)Wave functionNuclear Physics A

Propriétés spectrales des filtres usuels en économie : désaisonnalisation par CENSUS XII, et différences d'ordre d

1985

This study concerns the efficiency of usual statistical filters in economics to reduce the tendencial and seasonal components : the moving average processes of CENSUS Xll seasonal adjustment method and the difference sof d order early proposed by BOX-JENKINS. We are herein using the spectral and cospectral analyses to know whether the other components keep stable in the filtering process and whether the leads and lags found on the basis of the initial original data are kept after these filtering processes. One application illustrates the problems by means of monthly indicators that are highly representative of French economic evolution from 1963 up to 1982.This theoretical and empirical res…

FiltreCENSUS XIIDifferenciationDifférentiation[ SHS.ECO ] Humanities and Social Sciences/Economies and financesSpectral analysisLeads and Lags[SHS.ECO] Humanities and Social Sciences/Economics and FinanceFiltering[SHS.ECO]Humanities and Social Sciences/Economics and FinanceAvance-retardAnalyse spectrale

false

1985

Comparaison de deux polyarylates nitrile ayant des groupes d'espace differents [(CH 2 ) 2 ou (CH 2 ) 6 ]

chemistry.chemical_classificationPermittivityChemistryLiquid crystalLiquid crystallinePolymer chemistryPhysical chemistryDielectric lossPolymerDielectricPendant groupDie Makromolekulare Chemie, Rapid Communications

false

1985

Using a self-constructed light scattering apparatus, the pressure dependence of the demixing temperature of solutions of PVC 20 000, PVC 37 000 and PVC 70 000 in THE/water was determined up to 1 000 bar for different compositions of the mixed solvent. (The numbers in the codes of the PVC specimens are their approximate molecular weights.) In contrast to the thetasolvents o-xylene and phenetole, the solubility decreases with increasing pressure for all molecular weights and compositions under investigation typically by about 1 K/100 bar. The evaluation of the experimental findings demonstrates that the volume fraction of the nonsolvent in the mixed solvent, φ, is the variable that governs ph…

SolventHildebrand solubility parameterChromatographyAtmospheric pressureChemistryPolymer chemistryVolume fractionThermodynamicsFractionationSolubilityLight scatteringBar (unit)Die Makromolekulare Chemie

Non-Benzenoid Conjugated Carbocyclic Compounds. Von D. Lloyd. Elsevier, Amsterdam 1984. XVI, 431 S., geb. HFI. 262.00. – ISBN 0-444-42346-X

1985

Polymer scienceChemistryStereochemistryGeneral MedicineConjugated systemAngewandte Chemie

I(py)2BF4, a New Reagent in Organic Synthesis: General Method for the 1,2-Iodofunctionalization of Olefins

1985

chemistry.chemical_compoundGeneral methodChemistryReagentOrganic chemistryOrganic synthesisGeneral MedicineCombinatorial chemistryAngewandte Chemie International Edition in English

Cost and financing of education - Kano State (Nigeria)

1985

référence interne : 85062

Coût de l'éducationAfriqueFinancement de l'éducation[SHS.EDU]Humanities and Social Sciences/Education[SHS.EDU] Humanities and Social Sciences/EducationNigéria

Absence of lipid peroxidation as determined by ethane exhalation in rats treated with 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD).

1985

The exhalation of ethane is widely used as an indicator of in vivo lipid peroxidation. To test the hypothesis that lipid peroxidative events are involved in the toxicity of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), we administered a lethal dose of TCDD (60 μg/kg), IP to male Sprague Dawley rats (160–180 g) and measured by gas chromatography the exhalation of ethane into the atmosphere of a closed all-glass exposure chamber. TCDD-treated rats exhaled only slightly more ethane than control rats at a single time point 7 days following TCDD administration. Since the exhalation of ethane is the net result of the endogenous production of the gas and its metabolic degradation, the latter was …

Malemedicine.medical_specialtyLipid PeroxidesPolychlorinated DibenzodioxinsHealth Toxicology and MutagenesisEndogenyToxicologyDioxinsLipid peroxidationchemistry.chemical_compoundCytochrome P-450 Enzyme SystemIn vivoInternal medicinemedicineAnimalsheterocyclic compoundsEthaneChemistryLethal doseExhalationRats Inbred StrainsGeneral MedicineMetabolismTetrachlorodibenzo-p-dioxinRatsstomatognathic diseasesEndocrinologyBiochemistryToxicityArchives of toxicology

false

1985

Investigations with ca. 100 organic liquids in a temperature range from −20°C to 90°C result in a survey of the solubility behaviour of PVC. The experimental results were compared with the predictions of the solubility parameter theory: Accepting δ = 9,75 (cal/cm3)1/2 as the solubility parameter for PVC, all solvents (except ketones in which PVC is soluble independent of their solubility parameters) are located within the range of δPVC ± 0,75. Only three of the 100 liquids examined turned out to be (endothermal) theta-solvents, namely the aromatic solvents o-xylene, phenetole and dimethyl phthalate. The theta-temperatures in o-xylene and phenetole were determined viscometrically by means of…

SolventViscosityHildebrand solubility parameterchemistry.chemical_compoundRheologyChemistryIntrinsic viscosityPolymer chemistryOrganic chemistryThermodynamicsSolubilityAtmospheric temperature rangeDimethyl phthalateDie Makromolekulare Chemie

La aparicion de la ensenanza superior de masa

1985

ensenanza superior de masa[SHS.EDU]Humanities and Social Sciences/Education[SHS.EDU] Humanities and Social Sciences/Education[ SHS.ECO ] Humanities and Social Sciences/Economies and finances[ SHS.EDU ] Humanities and Social Sciences/Education[SHS.ECO]Humanities and Social Sciences/Economics and Finance[SHS.ECO] Humanities and Social Sciences/Economics and Finance

false

1985

chemistry.chemical_classificationViscosityPhase transitionChain (algebraic topology)ChemistryLiquid crystallineLiquid crystalPolymer chemistryPolymerDie Makromolekulare Chemie, Rapid Communications

Glacier drainage and sandur formation at Kötlujökull, South Iceland

1985

Abstract Over a number of years research on a stretch of the southeastern glacier margin of Kotlujokull in South Iceland, 8 km in length, has focused on correlating the manner of glacier drainage with the genesis of sandar, exemplified by the recent evolution of the glacier foreland. The research has yielded the following results. During an initial period, beginning prior to 1945 and ending between 1966 and 1975, a belt of moraines about 1 km wide was destroyed in stages, except for a few remnants, by 11 outbreaks of subglacial meltwater at different times and locations along the glacier front. These outbursts were associated with the genesis of “ordinary”; sandar, which are referred to her…

geographyGlacier terminusgeography.geographical_feature_categoryGeography Planning and DevelopmentTidewater glacier cycleGlacierGlacier mass balanceMoraineOutwash plainGeneral Earth and Planetary SciencesPhysical geographyGlacier forelandGeneral Agricultural and Biological SciencesMeltwaterGeomorphologyGeologyGeneral Environmental SciencePolar Geography and Geology

A Pesquisa Francesca sobre as relacoes entre formacao e emprego

1985

Reprend en partie Jean-Jacques Paul, Les analyses françaises des relations formation-emploi, Revue française de Pédagogie, 69, 1984; International audience

Recherche en éducation[SHS.EDU]Humanities and Social Sciences/Education[SHS.EDU] Humanities and Social Sciences/EducationFranceRelation formation-emploi

Polyalbumin receptors, hepatitis B surface antigen (HBsAg), and HBsAg/IgM complexes in HBsAg positive patients with and without delta superinfection.

1985

Receptors for polymerized human albumin are found at high litres during high-level hepatitis B virus (HBV) replication and in small amounts in chronic low-level infection. Complexes between hepatitis B surface antigen (HBsAg) and IgM without specificity for HbsAg are expressed in a pattern similar to that of receptors. Anti-albumin antibodies could be involved in their formation. Delta infection depresses the synthesis of gene products of HBV. To assess whether delta modifies the expression of receptors on HBsAg and the level of HBsAg/IgM complexes, and if anti-albumin antibodies are actually part of the complex, we tested sera from 86 subjects with acute and chronic HBV infection. Our find…

HBsAgRadioimmunoassayEnzyme-Linked Immunosorbent AssayReceptors Cell SurfaceSerum Albumin HumanAntigen-Antibody ComplexHepatitis b surface antigenmedicine.disease_causeVirologymedicineHumansReceptorSerum AlbuminHepatitis B virusHepatitis B Surface AntigensbiologyAlbuminvirus diseasesReceptors AlbuminHepatitis BVirologydigestive system diseasesTiterInfectious DiseasesViral replicationImmunoglobulin MImmunologyAcute DiseaseChronic Diseasebiology.proteinAntibodyJournal of medical virology

Induction and suppression of cytochromes P-450 in rat tissues

1985

ChemistryBiochemistryBiochemical Society Transactions

3H-cyproterone acetate: binding characteristics to human uterine progestagen receptors

1985

The availability of tritium labeled cyproterone acetate (CPA) facilitated the systematic investigation of the binding characteristics of this compound for human uterine progesterone receptors (PgR). The binding parameters of 3H-CPA are compared to those of 3H-R5020 and 3H-progesterone. The rate constants of association (k1M-1sec-1) to PgR were 7.8 X 10(3) for 3H-R5020, 4.5 X 10(4) for 3H-progesterone and 4.0 X 10(4) for 3H-CPA. The rate constants of dissociation (k-1, sec-1) were 3.6 X 10(-5) for 3H-R5020, 21.3 X 10(-5) for 3H-progesterone and 17.8 X 10(-5) for 3H-CPA. The Kd-values (M), as obtained by titration analysis and subsequent Scatchard plot analysis were 1.2 X 10(-9) for 3H-R5020,…

medicine.medical_specialtyEndocrinology Diabetes and Metabolismmedicine.medical_treatmentStatistics as TopicTritiumBinding CompetitivePromegestoneSteroidchemistry.chemical_compoundEndocrinologyInternal medicineCentrifugation Density GradientmedicineHumansPotencyheterocyclic compoundsCyproteroneBinding siteCyproterone AcetateReceptorProgesteroneUterusCyproterone acetateKineticsEndocrinologychemistryDihydrotestosteronecardiovascular systemCyproteroneFemaleTritiumReceptors Progesteronehormones hormone substitutes and hormone antagonistsmedicine.drugJournal of Endocrinological Investigation

On equity in education again : an international comparison

1985

This article proposes an approach to answering two questions: first, does investment in education help growth; second, does the allocation of investment in education matter? I develop a model where individual ability is heterogeneous and education both ...

Organizational Behavior and Human Resource ManagementEconomics and EconometricsEquity (economics)Financial economicsStrategy and Management[SHS.EDU]Humanities and Social Sciences/Education[SHS.EDU] Humanities and Social Sciences/Education05 social sciences050301 educationInternational economicsSystème éducatifManagement of Technology and Innovation0502 economics and businessComputingMilieux_COMPUTERSANDEDUCATIONEconomicsÉducationEducation policy050207 economicsOpen-ended investment companyComparaison0503 educationComputingMilieux_MISCELLANEOUSÉquitéEducation economics

Synthesis and structural studies by infrared and Mössbauer spectroscopy of adducts of tin(IV) and organotin(IV) derivatives with 2,2′-azopyridine

1985

Abstract A number of complexes have been prepared by the reaction between 2,2′-azopyridine(AZP) and tin(IV) halides and organotin(IV) halides, and characterized by elemental analysis and infrared and variable temperature 119Sn Mossbauer spectroscopies. All of the new compounds have 1:1 stoichiometry, with the AZP ligand occupying two coordination sites by bonding through one of the ring and one of the azo group nitrogen atoms, to give rise to distorted octahedral structures. In the diorganotin complexes the two organic groups occupy trans positions. The infrared and Mossbauer spectroscopic data suggest that these compounds are monomeric in the solid state.

Azo compoundInfraredLigandInorganic chemistrychemistry.chemical_elementAdductInorganic Chemistrychemistry.chemical_compoundCrystallographychemistryOctahedronMössbauer spectroscopyMaterials ChemistryPhysical and Theoretical ChemistryTinStoichiometryInorganica Chimica Acta

false

1985

A block copolymer (6) with both hydrophilic and hydrophobic regions was synthesized, in order to examine its interaction with model membranes and its uptake by living cells. The copolymer comprised poly(ethylene oxide) and poly(L-lysine) with 50 mol-% substitution of the e-amino groups with palmitoyl groups. To permit 125I-labelling, p-methoxyphenyl residues (1–4 mol-%) were incorporated into the block copolymer and into a poly(ethylene oxide) used for comparison. Sudan Red 7 B solubilization studies indicated that the block copolymer, but not the homopolymer, forms micelles. Differential scanning calorimetry of dipalmitoyl-phosphatidylcholine liposomes indicated that the block copolymer in…

chemistry.chemical_classificationLiposomechemistry.chemical_compoundMembraneEthylene oxidechemistryPinocytosisPolymer chemistryCopolymerChemical modificationPolymerMicelleDie Makromolekulare Chemie

I(py)2BF4, ein neues Reagens: allgemeine Methode für die 1,2-Iodfunktionalisierung von Olefinen

1985

chemistry.chemical_classificationchemistry.chemical_compoundHydrocarbonChemistryGeneral MedicineMethanolMedicinal chemistryChemical reactionDichloromethaneAngewandte Chemie

A neutron diffraction study of the glass transition in (KBr)0.47(KCN)0.53

1985

Abstract The molecular crystal (KBr) 0.47 (KCN) 0.53 has been investigated by elastic neutron diffraction at the transition from the paraelastic to the orientational glass state. The freezing temperature is characterized by the onset of a momentum transfer dependent broadening of the diffraction lines indicating the transition from a crystalline to an amorphous state.

inorganic chemicalsDiffractionchemistry.chemical_classificationChemistrydigestive oral and skin physiologyNeutron diffractionMomentum transferPhysics::OpticsGeneral ChemistryCondensed Matter PhysicsAmorphous solidCrystalCrystallographybiological sciencesMaterials ChemistryGlass transitionOrientational glassInorganic compound

L'informatique à l'école élémentaire en France

1985

Communication faite à l'occasion du "INCONTRO INTERNAZIONALE" Castello Pasquini CASTIGRIONCELLO 29 - 30 MARZO 1985 "IL BAMBINO TECHNOLOGICO 85"; International audience

Nouvelle technologie éducativeTechnologie de l'éducation[SHS.EDU]Humanities and Social Sciences/EducationEnseignement élémentaire[SHS.EDU] Humanities and Social Sciences/EducationFranceInformatiqueÉcole élémentaireComputingMilieux_MISCELLANEOUSNTIC

Quelques menthes poivrees cultivees a Grasse: caracteres botaniques et composition des huiles essentielles en 1ere et 2eme recolte

1985

National audience

[SDV] Life Sciences [q-bio][SDV]Life Sciences [q-bio]MENTHE POIVREEBOTANIQUEComputingMilieux_MISCELLANEOUS

Electronic polarizability of small metal spheres

1985

We present the results of calculations for the ground-state electron structure, static polarizability, and dynamic response of small metal (jellium) spheres in vacuum or embedded in a dielectric. Fully self-consistent time-dependent density-functional methods are used. In particular, the static and dynamic responses to an incident electric field (dipolar polarizability and photoabsorption) are obtained. The results show substantial deviations from either classical or approximate quantum-mechanical solutions, and provide reference data for simplified treatments. Peer reviewed

small metalsMetalMaterials scienceCondensed matter physicsPolarizabilityPhysicsvisual_artelectron structurevisual_art.visual_art_mediumPhysics::Atomic and Molecular ClustersSPHERES

Physicochemical and functional characterization of the polymerization process of the Geodia cydonium lectin

1985

The extracellularly localized, galactose-specific lectin from the sponge Geodia cydonium binds at one class of sites, 40 mol Ca2+/mol lectin with an association constant (Ka) of 0.3 X 10(6)M-1. Stoichiometric calculations reveal that in the extracellular milieu 22 mol Ca2+ (maximum) are complexed per mol lectin. Binding of Ca2+ to the lectin increases its apparent Mr from 44000 to 56000 (electrophoretic determination) or from 36500 to 53500 (high-pressure liquid gel chromatographical determination); the s20, w increases from 4.3 S to 4.5 S if Ca2+ is added to the lectin. In the presence of Ca2+ the lectin undergoes a conformational change perhaps by expanding the carbohydrate side chains wh…

Conformational changeChemical PhenomenaStereochemistryGlycoconjugateBiologyBiochemistryMicechemistry.chemical_compoundBiopolymersNephelometry and TurbidimetryLectinsCell AdhesionAnimalsGeodiaLeukemia L5178chemistry.chemical_classificationLectinbiology.organism_classificationPoriferaMolecular WeightChemistryMicroscopy ElectronEnzymePolymerizationchemistryBiochemistryGalactosebiology.proteinCalciumGlycoproteinProtein BindingEuropean Journal of Biochemistry

Photolysis of enol acetates and α-bromo derivatives ofo-(acyloxy)acetophenones

1985

UV irradiation of enol acetates 3a – g in benzene gives mainly o-(acetoxy)acetophenones 2 and 2-methylchromones 4. Under the same conditions, the dimethyl derivatives 3h and 3i remain unaffected. The α-bromo ketone 5a gives rise to mixtures of o-(acetoxy)acetophenone (2a), the diketone 6, and/or α-acetoxy-o-hydroxyacetophenone (7), depending on the irradiation conditions. The similarities and differences between the two series of experiments, as well as their possible mechanistic implications, are discussed. Photolyse von Enolacetaten und α-Bromderivaten von o-(Acyloxy)acetophenonen UV-Bestrahlung der Enolacetate 3a – g in Benzol liefert o-(Acetoxy)acetophenone 2 und 2-Methyl-chromone 4 als…

chemistry.chemical_classificationDiketoneKetoneIntramolecular reactionChemistryStereochemistryOrganic ChemistryPhotodissociationNuclear magnetic resonance spectroscopyEnolMedicinal chemistrychemistry.chemical_compoundPhysical and Theoretical ChemistryBenzeneAcetophenoneLiebigs Annalen der Chemie

Les programmes et projets en éducation dans la zone rurale du CEARA : analyse critique

1985

International audience

Analyse critique[SHS.EDU]Humanities and Social Sciences/Education[SHS.EDU] Humanities and Social Sciences/EducationProjet éducatifAmérique latineProgramme éducatifComputingMilieux_MISCELLANEOUSBrésilZone rurale