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111.
112.
Reginald T. Cahill 《General Relativity and Gravitation》2002,34(10):1637-1656
Process Physics models reality as self-organising relational or semantic information using a self-referentially limited neural network model. This generalises the traditional non-process syntactical modelling of reality by taking account of the limitations and characteristics of self-referential syntactical information systems, discovered by Gödel and Chaitin, and the analogies with the standard quantum formalism and its limitations. In process physics space and quantum physics are emergent and unified, and time is a distinct non-geometric process. Quantum phenomena are caused by fractal topologicaldefects embedded in and forming a growing three-dimensional fractal process-space. Various features of the emergent physics are briefly discussed including:quantum gravity, quantum field theory, limited causality and the Born quantum measurement metarule, inertia, time-dilation effects, gravity and the equivalence principle, a growing universe with a cosmological constant, black holes and event horizons, and the emergence of classicality. 相似文献
113.
114.
Mitchell RH Bohne C Wang Y Bandyopadhyay S Wozniak CB 《The Journal of organic chemistry》2006,71(1):327-336
[structure: see text] The synthesis of the multistate photochromic switch 3 is described. This switch contains three dihydropyrene (DHP) units in the most conjugated fully closed form 3-c,c,c. The thermally stable form has the central DHP unit open and is 3-c,o,c. NMR and laser flash photolysis experiments were used to characterize the multiple states in the photoswitching of 3 by visible and UV light. Three of the possible five isomeric states of 3-c,o,c were observed. Irradiation of 3-c,o,c by visible light led to the formation of 3-o,o,o via the isomer 3-c,o,o as an intermediate, which were observed by NMR. Irradiation by UV light led to the formation of 3-c,c,c, which decays with a lifetime of 7.5 ms. 相似文献
115.
Malononitriles are valuable synthetic intermediates for many applications, including the synthesis of herbicides and other biologically active molecules, and the synthesis of chiral ligands for asymmetric catalysis. This article describes the development of a procedure for the conversion of primary nitriles to malononitriles using dimethylmalononitrile, a commercial, non-toxic, carbon-bound source of electrophilic cyanide. This procedure avoids the use of toxic cyanide or malononitrile as a starting material. This protocol is further applied to the dicyanation of benzyl Grignard reagents, generated from benzyl bromides, yielding fully functionalized malononitriles from a nitrile-free precursor. 相似文献
116.
Reginald J Exton R.Jeffrey Balla 《Journal of Quantitative Spectroscopy & Radiative Transfer》2004,86(3):267-283
Fluorescence of I2 excited by an ArF excimer laser at has been studied in the presence of 10 buffer gases (He, Ne, Ar, Kr, Xe, N2, O2, air, CF4, and SF6) over the pressure range from 0 to . At low pressure, the fluorescence is dominated by the bound-bound and bound-free (McLennan band) emission for . With increasing pressure, significant fractions of the D state population are collisionally transferred to the D′ state; this results in strong band flourescence at . A simple four-level model is developed to describe these processes. Quenching and transfer rate coefficients are measured for the 10 gases. With the exception of Xe, O2, and air, which exhibit reactive quenching in addition to collisional quenching, the 340-nm-band fluorescence is resistant to quenching. 相似文献
117.
The reaction of cysteine (cys) with dopaminoquinone (DQ) to form (mainly) 5-cysteinyl-dopamine (5-cys-DA) is of interest because it is known to play a role in the production of melanin in the mammalian brain. To gain insight into this important reaction, an in vitro detailed kinetic study was undertaken. It has been established that cys reacts with DQ via the initial reversible formation of an intermediate adduct or complex and that this adduct then decomposes to form 5-cys-DA. A little 2-cys-DA, is almost certainly formed at the same time but its presence could not be kinetically investigated. Clarification of the kinetic data was aided by following the reaction of DQ with a cys analogue, mercaptoacetic acid (maa). Maa was found to react in a similar fashion, but also forms, reversibly, a bis-complex. This bis-complex, 2,5-(maa)(2)-dopaminoquinone, is in equilibrium with the di-protonated compound but neither of these species reacts further over the timescale employed in these kinetic studies. Equilibrium constants and first-order rate constants have been extracted from the data and the cys complex is found to be weaker than its maa analogue by an order of magnitude (K(cys)=(1.09 +/- 0.02 x 10(-3); K(1,maa)=(7.45 +/- 0.11 x 10(-3)). (Note that the possibility that cys also forms a bis-complex at much higher cys concentrations cannot be excluded.) The rates of decomposition differ markedly-the cys complex has the value k(cys)= 1830 +/- 50 s(-1) whereas the rate constant for the decomposition of the maa complex is k(maa)= 69.3 +/- 0.02 s(-1) and we attribute this difference to the effect of the positive charge carried by the amino-group on cys. Finally, the constants obtained are used to compare the reactivity of thiol addition with ring cyclization (U. El-Ayaan, E. Herlinger, R. F. Jameson, and W. Linert, J. Chem. Soc., Dalton Trans., 1997, 2813-2818) and we show how this has important implications concerning the production of neuromelanin. 相似文献
118.
Trask AV Shan N Motherwell WD Jones W Feng S Tan RB Carpenter KJ 《Chemical communications (Cambridge, England)》2005,(7):880-882
A method of inducing specific polymorph transformations is exemplified with two single-component systems, whereby a given crystal form undergoes conversion when subjected to solid state grinding in the presence of a minor quantity of a certain solvent. 相似文献
119.
Horacio H. Yanasse Alan S. I. Zinober Reginald G. Harris 《The Journal of the Operational Research Society》1991,42(8):673-683
In this paper an algorithm for a cutting stock problem in the wood industry is presented. Cuts are of guillotine type and requirements have to be met exactly, i.e. no over- or under-production is allowed. There are several different board sizes from which panels can be cut and the problem is to find the best mix of boards and respective cutting patterns that satisfies the demand for panels with minimum wastage. The heuristic algorithm uses a pattern-building procedure combined with an enumeration scheme for the mix of boards. 相似文献
120.
Andréasson J Kodis G Terazono Y Liddell PA Bandyopadhyay S Mitchell RH Moore TA Moore AL Gust D 《Journal of the American Chemical Society》2004,126(49):15926-15927
A molecule-based binary half-adder with optical inputs and outputs has been demonstrated. The half-adder consists of two photochromic organic molecules in solution and a third-harmonic-generating crystal. One substance acts as an AND Boolean logic gate and the other as an XOR gate. Inputs are laser pulses at 1064 or 532 nm that initiate photoisomerization reactions. Outputs are the optical absorbance of a fullerene radical anion (AND gate) and fluorescence of a porphyrin (XOR gate). The system carries out binary addition based on the laser input pulses. Half-adders in combination are capable of carrying out all mathematical operations necessary for digital computing. 相似文献