Search results for "Rota"
showing 10 items of 2706 documents
Еmοсiοnālāѕ аttīѕtībаѕ vеiсināšаnа rοtаļāѕ 3 -4 gadu veciem bērniеm pirmsskolas pedagoģiskajā procesā
2017
Šī dаrbа mērķiѕ ir раrādīt еmοсiοnālā intеlеktа nοzīmi аgrīnā bērnībā, turklāt tајā ir uzѕvērti rοtаļаѕ nοzīmе, аttīѕtītοt еmοсiοnālο intеlеktu bērnu рirmајοѕ dzīvеѕ gаdοѕ. Kvаlifikāсiјаѕ dаrbѕ bаlѕtāѕ uz tеοrētiѕkāѕ litеrаtūrаѕ рārѕkаtā un аutοrеѕ vеiktа еkѕреrеmеntа (nοvērοјumа). Dаrbа gаlvеnаiѕ аѕреktѕ biја izрrаѕt аkаdēmiѕkuѕ mаtеriāluѕ, сitu аutοru рētīјumuѕ, rаkѕtuѕ, grāmаtаѕ, lеkсiјаѕ un diѕkuѕiјаѕ, lаi ѕniеgtu ѕаrеžģītu рriеkšѕtаtu раr šο раrādību. Аutοrе izvirzīја ѕеkοјοšu dаrbа hiрοtēzi – раrеizi οrgаnizēјοt rοtаļnοdаrbībаѕ vаr раnākt 3-4 gаdu vесο bērnu еmοсiοnālāѕ аttīѕtībаѕ vеiсināšаnu. Dаrbѕ ѕаѕtāv nο 53 lараѕрuѕēm, 8 tаbulām, 2 аttēliеm un 5 рiеlikumiеm.
Vāļu galu aproces Latvijā: studiju darbs
1944
[3]Rotaxanes and [3]pseudorotaxanes with a rigid two-bidentate chelate axle threaded through two coordinating rings
2009
New [3]rotaxanes and [3]pseudorotaxanes have been synthesised using the “gathering and threading” effect of copper(I). By using click chemistry as the “stoppering” reaction, a good yield of the [3]rotaxane was obtained, either as a dicopper complex or as a metal-free compound after demetallation. The axle contains a central rigid aromatic block incorporating two bidentate chelates, and the threaded macrocycles are 30-membered rings. A model dicopper(I) [3]pseudorotaxane whose axle was end-functionalised by triisopropylsilyl groups could be crystallised and studied by X-ray diffraction. A particularly attractive structure was obtained showing a “slanted” geometry for the two rings and the ax…
A new method of anomeric protection and activation based on the conversion of glycosyl azides into glycosyl fluorides
1993
Glycosyl azides provide reliable anomeric protection stable to conditions for hydrolytic removal of ester groups, for reductive opening or release of acetalic diol protection, for the introduction of ether-type protection, and for glycosylation processes. The utility of this anomeric protection is further enhanced as glycosyl azides may be converted into glycosyl fluorides, which can be activated for glycosylation reactions. To this end, glycosyl azides have been subjected to 1,3-dipolar cycloaddition with di-tert-butyl acetylenedicarboxylate. On treatment with hydrogen fluoride-pyridine complex the N-glycosyl triazole derivatives directly give glycosyl fluorides.
Chiral Polyisocyanates from an Azomonomer with a Very High Chiral Induction
2001
The synthesis of new chiral polyisocyanates is described. For this purpose a new chiral azobenzene containing monomer with the chiral center in α-position to the isocyanate group was synthesized. The anionic copolymerization was carried out in THF as solvent with potassium cyanide that was complexed by 18-crown-6 as initiator. This allowed a better control of the reaction and thereby the synthesis of polyisocyanates with a fairly low polydispersity. The copolymers show an extremely high transfer of chirality from the chiral side groups to the helical backbone in dilute solution. Copolymers with only 1.6 mol % of chiral side groups show nearly the full optical rotation and exist predominantl…
SIA “Daiļrade Koks” saimnieciskās darbības analīze.
2019
Kvalifikācijas darba tēma: SIA „Daiļrades koks” saimnieciskās darbības analīzi. Saimnieciskās darbības rezultātu lietotāju loks ir ļoti plašs, un to nosacīti var iedalīt vairākās kategorijās atkarībā no analīzes mērķa un interešu objekta – vadība, īpašnieki, darījumu (biznesa partneri, kreditori, valsts institūcijas, darbinieki, finanšu analītiķi, apdrošināšanas kompānijas, arodbiedrības). Kvalifikācijas darba mērķis: izvērtēt mēbeļu jomas uzņēmuma SIA „Daiļrades koks” saimniecisko darbību. Darbs sastāv no trijām nodaļām. Darba pirmajā nodaļā apskatīti, saimnieciskās un finanšu analīzes teorētiskie aspekti, saimnieciskās un finanšu analīzes būtība, lietotāji, metodes, kā arī finanšu analīze…
Fundamentals and applications of stir bar sorptive dispersive microextraction: A tutorial review
2021
Current trends in sample preparation focus on the miniaturization of the process resulting in what is known as microextraction techniques. Among them stir bar sorptive dispersive microextraction (SBSDME) is one of the most recent techniques. It was presented a few years ago as a hybrid microextraction technique that combines the principles of stir bar sorptive extraction (SBSE) and dispersive solid phase extraction (DSPE). This novel technique introduces, into the sample solution, a bar-shaped magnet coated with a magnetic (nano)material, which is maintained on the surface by magnetism. Once stirring starts, the competitive action between magnetism and rotational force is exploited. At low …
Synthesis and characterisation of N-glycosyl amines from the reaction between 4,6-O-benzylidene-D-glucopyranose and substituted aromatic amines and a…
2001
Twelve N-glycosyl amines were synthesised using 4,6-O–benzylidene-D-glucopyranose and different substituted aromatic amines, including some diamines that resulted in bis-glycosyl amines. Another set of six N–glycosyl amines was synthesised using different hexoses and pentoses and 2–(o–aminophenyl)benzimidazole. All compounds were isolated as solid products and purified, their elemental compositions were established, and these were characterised by NMR (1H and 13C), UV–Vis, and FTIR spectroscopy, by FAB mass spectrometry (molecular-ion peaks gave molecular weights), and by their optical rotations. While the protected saccharide, 4,6-O-benzylidene-D-glucopyranose, exists as a mixture of β and…
Verso una dimensione narrativa delle mappe
2021
Tra il pensiero e la costruzione dell’architettura il disegno ha un ruolo baricentrico per connettere i diversi protagonisti di una realizzazione e per coinvolgere la collettività facendo percepire inedite prospettive. La scrittura si rivela utile per esplicitare ciò che nella grafica è sotteso e per stabilire un ordine nuovo nel ragionamento progettuale. I rapporti fra segni e significati si moltiplicano nei sistemi informativi recenti in cui si ha la sensazione di poter dire moltissimo (dati numerici e spaziali) ma a volte sfugge quella sintesi indispensabile per una interpretazione concreta, finalizzata alla costruzione di possibili esperienze fisiche. Per l’esplorazione dell’uso di dive…
On the mechanism of catalytic isomerization of xylenes. Molecular orbital studies
1979
Abstract On the basis of CNDO/2 molecular orbital calculations, we postulate the following detailed mechanism for the catalytic isomerization of xylenes which explains the initial product distributions and also our previous finding that the reaction is intramolecular: (i) adsorption of xylene on a surface acid site to form a Wheland-type complex; (ii) disrotatory cyclization of the protonated species into a bicyclo[3, 1, 0]hexenyl complex; (iii) migration of the methylene bridge to a new side of the pentagonal ring; (iv) change of the new bicyclic species back into the corresponding Wheland-type complex; (v) desorption of the xylene isomer from the surface of the catalyst. The overall rate …