V Chem Shodstvo Drevnegrecheskogo I Drevnerimskogo Teatrov
The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is the most prominent example of a group of reactions named click-reactions (Figure 1, Page 2). According to Sharpless`s definition, these reactions are characterized by high yields, mild reaction conditions, and by their tolerance of a broad range of functional groups. 1 Typically, the.
‘As is well known the principle of virtual velocities transforms all statics into a mathematical assignment, and by D’Alembert’s principle for dynamics, the latter is again reduced to statics. Although it is is very much in order that in gradual training of science and in the instruction of the individual the easier precedes the more difficult, the simple precedes the more complicated, the special precedes the general, yet the min, once it has arrived at the higher standpoint, demands the reverse process whereby all statics appears only as a very special case of mechanics.’ Collected Works (1877), Vol. Waldo Dunnington, Carl Friedrich Gauss: Titan of Science (2004), 412. And there are absolutely no judgments (or rules) in Mechanics which do not also pertain to Physics, of which Mechanics is a part or type: and it is as natural for a clock, composed of wheels of a certain kind, to indicate the hours, as for a tree, grown from a certain kind of seed, to produce the corresponding fruit. Accordingly, just as when those who are accustomed to considering automata know the use of some machine and see some of its parts, they easily conjecture from this how the other parts which they do not see are made: so, from the perceptible effects and parts of natural bodies, I have attempted to investigate the nature of their causes and of their imperceptible parts.’ Principles of Philosophy (1644), trans. Miller (1983), 285-6. ‘Thus far I have explained the phenomena of the heavens and of our sea by the force of gravity, but I have not yet assigned a cause to gravity.
Indeed, this force arises from some cause that penetrates as far as the centers of the sun and planets without any diminution of its power to act, and that acts not in proportion to the quantity of the surfaces of the particles on which it acts (as mechanical causes are wont to do) but in proportion to the quantity of solid matter, and whose action is extended everywhere to immense distances, always decreasing as the squares of the distances.’ The Principia: Mathematical Principles of Natural Philosophy (1687), 3rd edition (1726), trans. Bernard Cohen and Anne Whitman (1999), General Scholium, 943.
Item Metadata Title Reactive uptake kinetics of NO3 on multicomponent and multiphase organic mixtures containing unsaturated and saturated organics. Creator Publisher Royal Society of Chemistry Date Issued 2011-02-03 Description We investigated the reactive uptake of NO3 (an important night-time oxidant in the atmosphere) on binary mixtures containing an unsaturated organic (methyl oleate) and saturated molecules (diethyl sebacate, dioctyl sebacate, and squalane) which we call matrix molecules. These studies were carried out to better understand the reactivity of unsaturated organics in multicomponent and multiphase atmospheric particles. For liquid binary mixtures the reactivity of methyl oleate depended on the matrix molecule. Assuming a bulk reaction, varied by a factor of 2.7, and assuming a surface reaction HSmatrixKSmatrixkSoleate varied by a factor of 3.6, where and HSmatrixKSmatrixkSoleate are constants extracted from the data using the resistor model. For solid–liquid mixtures, the reactive uptake coefficient depended on exposure time: the uptake decreased by a factor of 10 after exposure to NO3 for approximately 90 min.
By assuming either a bulk or surface reaction, the atmospheric lifetime of methyl oleate in different matrices was estimated for moderately polluted atmospheric conditions. For all liquid mixtures, the lifetime was in the order of a few minutes (with an upper limit of 35 min). These lifetimes can be used as lower limits to the lifetimes in semi-solid mixtures.
Our studies emphasize that the lifetime of unsaturated organics (similar to methyl oleate) is likely short if the particle matrix is in a liquid state. Kirgizcha tush zhoru kitep. Genre Type Language eng Date Available 2012-02-03 Provider Vancouver: University of British Columbia Library Rights Attribution-NonCommercial-NoDerivatives 4.0 International DOI 10.14288/1.0041867 URI Affiliation Citation Xiao, Song, Bertram, Allan K. Reactive uptake kinetics of NO3 on multicomponent and multiphase organic mixtures containing unsaturated and saturated organics.