965 resultados para qualitative synthesis
Resumo:
Binuclear complexes of rhodium(I) of the type [(dien)(X)Rh(μ-N-N)Rh(X)(dien)] (dien = 1,5-cyclooctadiene or norbornadiene; N-N = pyrazine, 4,4′-bipyridine or Phenazine and X = Cl or Br) with bridging heterocycles have been isolated and their reactions with carbon monoxide, 2,2′-bipyridine and 1,10-phenanthroline investigated. The crystal structure of [(COD)(Cl)Rh(μ-pyrazine)Rh(Cl)(COD)] has been determined.
Resumo:
Polycrystals of orthorhobic carbonates RCO3 (R = Sr, Ba and Pb) were synthesised for the first time using formic acid as mineraliser. The unit cell parameters of this synthetic pure carbonates are: BaCO3:a=5.309, B=8.889, C=6.401; srCO3:a=5.108, B=8.420, C=6.040; PbCO3: A=5.176, B=8.511, C=6.137.
Resumo:
Pro gradu- tutkielmassani tarkastelen suomi-ranska kaksikielisyyden kehittymistä perheissä, joissa vanhemmilla on eri äidinkieli. Työni tavoitteena on ollut tutkia kuinka eri ympäristötekijät vaikuttavat kaksikielisyyden omaksumiseen ja miten perheiden erilainen panostus vähemmistökielen, ts. kielen joka ei esiinny ympäristössä, oppimiseen näkyy saavutetuissa tuloksissa. Tutkimukseeni osallistui 13 perhettä, joilla on 10-12 vuotiaita, ranskaa ja suomea päivittäin käyttäviä lapsia. Lapsia oli yhteensä 18. Voidakseni tarkastella myös kieliympäristön vaikutusta oppimiseen valittiin perheistä kuusi Suomesta ja seitsemän Ranskasta sekä Sveitsin ranskankieliseltä alueelta. Tutkimusmenetelmiini kuului vanhempien haastattelu perheen sosiolingvististen tekijöiden selville saamiseksi ja lasten kanssa keskustelu suullisen kielitaidon arvioimiseksi. Pääpaino kielitaidon arvioinnissa oli kuitenkin kirjallisella tekstillä, jonka lapset tuottivat molemmilla kielillä tekstittömän kirjan kuvien perusteella. Teksteistä suoritettiin virheanalyysit, joissa eri virheet jaettiin ortografisiin, semanttisiin ja kieliopillisiin virheisiin. Jokaiselle lapselle lasketiin myös keskiarvo, joka osoitti kuinka monta sanaa tekstissä oli jokaista virhettä kohti. Näiden keskiarvojen pohjalta tutkittiin yhteneväisyyksiä virhemäärien sekä perheiden sosiolingvististen tekijöiden kesken. Yhteenvedossa verrattiin myös tuloksia teoriaosassa esitettyihin kielitieteilijöiden tarjoamiin periaatteisiin. Tutkielman perusteella voidaan todeta, että ympäristön vaikutus näytetään usein aliarvioitaneen kaksikielisyyttä koskevissa teoksissa. Hyvään kielitaitoon vähemmistökielessä tarvitaan enemmän kuin yksi kieli - yksi henkilö menetelmä, jossa vanhemmat puhuvat lapselle omaa äidinkieltään. Hyviksi vahvistuskeinoiksi havaittiin varsinkin kaksikielinen koulu sekä useat vierailut toisen vanhemman kotimaahan. Varsinkin perheen nuorimpien lasten vähemmistökielen oppimiseen tulisi panostaa sillä näillä on syntymästään asti mahdollisuus käyttää enemmistökieltä myös vanhempien sisarusten kanssa. Kieliympäristön vaikutuksesta havaittiin, että Suomessa asuvat lapset hallitsivat yleisesti ottaen paremmin vähemmistökielensä kuin Ranskassa asuvat. Tähän pidettiin syynä ranskalais-suomalaisen koulun positiivista vaikutusta kielen oppimiselle sekä ranskankielen arvostettua asemaa Suomessa. Avainsanat: Kaksikielisyys, kieltenoppiminen, bilinguisme, acquisition des langues, couple mixte
Resumo:
Mixed ligand complexes of the type Ni(R-AB)(AC') and Ni(R-AC)(AB') where AB/AC denote N-bonded isonitroso- [3-ketoimino ligands, AB'/AC' denote the corresponding Obonded ligands and R = Me, Et, n-Pr are synthesised and characterised. The complexes are neutral with square planar geometry around nickel(II). The bonding isomerism of the isonitroso group is discussed on the basis of i.r. and 1H n.m.r. studies. The crystal structure of the title complex, Ni(n-Pr-IEAI)(IMAI') has been determined from diffractometer data by Patterson and Fourier methods and refined by least squares to R = 0.088 for 2209 observed reflections. Unit cell constants are: a = 11.945(2), b = 22.436(7), c = 13.248(5) ~, [3 = 95.13(2) ~ The space group is P2Jc with Z = 8. Niekel(II) has a square planar coordination of two imine nitrogens, an isonitroso-nitrogen (from n-Pr-IEAI) and another isonitrosooxygen (from IMAI').
Resumo:
The dimethoxytetralol gives on Vilsmeier reaction the dihydronaphthaldehyde (yield,92%), which on Grignard reaction with MeMgI affords the title compound (yield,�100%), the reactions constituting a high yield synthesis of this important anthracyclinone intermediate.
Resumo:
Stable solid adducts of SiF4 with the following aminocyclophosphazenes have been synthesized : N3P3(NHCH2CH2NH)(NMe2)4(,1 ) ; N3P3(NHCH2CH2NH)C14(,2 ) ; N3P3(NMe2)4C12(,3 ) ; N3P3(NHMe),,(4) ; N3P3(NMe2),, (5) ; N,P,(NHMe),, (6) ; N4P4(NMe2),, (7) ; and N,P,(NHBu'),, (8). They have been characterized by elemental analysis, i.r., and n.m.r. ( H, 31 P, and 19F) spectroscopy. The composition of the adducts varies depending on the ring size and also on the nature of the substituents on the phosphorus. The number of SiF4 molecules accommodated by the ligands is larger when the ring size is large, while it is less when the ligands contain chlorine. Except in the cases of ligands (1) and (2), bonding is through the ring nitrogens. With (I), both exocyclic nitrogen and ring nitrogen atoms, and with (2) only exocyclic nitrogen atoms, participate in co-ordination. In these two cases the silicon is six-co-ordinated, while in the other cases it is five-co-ordinated.
Resumo:
A new hydrazinium uranyl oxalate complex (N2H5)6[(UO2)2(C2O4)5]·2H2O has been prepared and characterized by chemical analysis, infrared, visible spectra and TG-DTA. The single crystal X-ray structure of the complex shows the presence of discrete N2H5+ cations, water molecules and [(UO2)2(C2O4)5]6− anions. In the anion, the linear uranyl groups are coordinated by two chelating bidentate oxalates and one bridging oxalate which lies on the center of symmetry between the two uranyl groups. The coordination polyhedron around each uranium atom is approximately a pentagonal bipyramid.
Resumo:
The caseins (αs1, αs2, β, and κ) are phosphoproteins present in bovine milk that have been studied for over a century and whose structures remain obscure. Here we describe the chemical synthesis and structure elucidation of the N-terminal segment (1–44) of bovine κ-casein, the protein which maintains the micellar structure of the caseins. κ-Casein (1–44) was synthesised by highly optimised Boc solid-phase peptide chemistry and characterised by mass spectrometry. Structure elucidation was carried out by circular dichroism and nuclear magnetic resonance spectroscopy. CD analysis demonstrated that the segment was ill defined in aqueous medium but in 30% trifluoroethanol it exhibited considerable helical structure. Further, NMR analysis showed the presence of a helical segment containing 26 residues which extends from Pro8 to Arg34. This is the first report which demonstrates extensive secondary structure within the casein class of proteins.
Resumo:
Ring-opening thermal polymerization of hexachlorocyclotriphosphazene (N3P3C&h)a s been investigated at 250 "C and at 1.333-Pa pressure using chlorocyclotriphosphazenes N3P3C15(N=PPh3) and N3P3Cl,.,(NMe2), (n = 2-4), salt hydrates, triphenylphosphine, and benzoic acid as initiators. The linear poly (dich1orophosphazene) products are phenoxylated, and the phenoxy polymers are characterized by gel permeation chromatography and dilute solution viscometry. Among the various initiators investigated, CaS04.2H20b rings about a high conversion (>60%) of N3P3C&to the linear [NPC12], polymer which possesses a high molecular weight (>5 X lo6). The rationale for the choice of the initiators and possible mechanism(s) of polymerization is discussed. Several mixed substituent polymers, [NP(OPh),(OC6H4Me-p)2,1, and [NP(OPh),(OCHzCF3)2,]nh, ave been prepared and their thermal properties evaluated.
Resumo:
Aim: To explore the role and needs of the family carer across different acute care contexts and their level of involvement in the care of their relative with dementia in this setting. Method: A pragmatic, exploratory-descriptive qualitative approach. A convenience sample of 30 family carers across three sites completed semi-structured interviews. Results: Family carers wanted to be involved in the acute care of their family member with dementia. They acknowledged the importance of a central source of information, educated staff, guidelines on roles and processes, and positive communication, as well as respect from staff for the carer’s knowledge of the older person and their needs. They also highlighted the need for medical staff to discuss with them the family member’s treatment and care. Conclusion: There is a need for family-focused interventions to improve communication and involvement of family in the care of family members with dementia in the acute setting.
Resumo:
In an effort to develop a fully computerized approach for structural synthesis of kinematic chains the steps involved in the method of structural synthesis based on transformation of binary chains [38] have been recast in a format suitable for implementation on a digital computer. The methodology thus evolved has been combined with the algebraic procedures for structural analysis [44] to develop a unified computer program for structural synthesis and analysis of simple jointed kinematic chains with a degree of freedom 0. Applications of this program are presented in the succeeding parts of the paper.
Resumo:
The reliability of the computer program for structural synthesis and analysis of simple-jointed kinematic chains developed in Part 1 has been established by applying it to several cases for whuch solutions are either fully or partially available in the literature, such as 7-link, zero-freedom chains; 8- and 10-link, single-freedom chains; 12-link, single-freedom binary chains; and 9-link, two-freedom chains. In the process some discrepancies in the results reported in previous literature have been brought to light.
Resumo:
The unified computer program for structural synthesis and analysis developed in Part 1 has been employed to derive the new and complete collection of 97 10-link, three-freedom simple-jointed kinematic chains. The program shows that of these chains, 3 have total freedom, 70 have partial freedom and the remaining 24 have fractionated freedom and that the 97 chains yield a total of 676 distinct mechanisms.
Resumo:
It is shown that lithium can be oxidatively extracted from Li2MoO3 at room temperature using Br2 in CHCl3. The delithiated oxides, Li2â��xMoO3 (0 < x â�¤ 1.5) retain the parent ordered rocksalt structure. Complete removal of lithium from Li2MoO3 using Br2 in CH3CN results in a poorly crystalline MoO3 that transforms to the stable structure at 280�°C. Li2MoO3 undergoes topotactic ion-exchange in aqueous H2SO4 to yield a new protonated oxide, H2MoO3.
Resumo:
Substituted polycyclic ethers and hydrocarbons are synthesised by the cycloaddition reaction of arynes with oxazoles.