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41.
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Permutation cellular automata are cellular automata defined by using finite maximal prefix codes. The overall dynamics of onesided and twosided permutation cellular automata is studied. For some classes of permutation cellular automata including the class of those defined by using finite maximal bifix codes, the overall dynamics is completely or partially described in terms of the codes used to define them. 相似文献
43.
High-Molecular-Weight Polynucleotides by Transferase-Catalyzed Living Chain-Growth Polycondensation
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Dr. Lei Tang Luis A. Navarro Jr. Prof. Ashutosh Chilkoti Prof. Stefan Zauscher 《Angewandte Chemie (International ed. in English)》2017,56(24):6778-6782
We present terminal deoxynucleotidyl transferase-catalyzed enzymatic polymerization (TcEP) for the template-free synthesis of high-molecular-weight, single-stranded DNA (ssDNA) and demonstrate that it proceeds by a living chain-growth polycondensation mechanism. We show that the molecular weight of the reaction products is nearly monodisperse, and can be manipulated by the feed ratio of nucleotide (monomer) to oligonucleotide (initiator), as typically observed for living polymerization reactions. Understanding the synthesis mechanism and the reaction kinetics enables the rational, template-free synthesis of ssDNA that can be used for a range of biomedical and nanotechnology applications. 相似文献
44.
Sebastian Fortin Olimpia Lombardi Juan Camilo Martínez González 《Foundations of Chemistry》2016,18(3):225-240
In the present paper we address the problem of optical isomerism embodied in the socalled “Hund’s paradox”, which points to the difficulty to account for chirality by means of quantum mechanics. In particular, we explain the answer to the problem proposed by the theory of decoherence. The purpose of this article is to challenge this answer on the basis of a conceptual analysis of the phenomenon of decoherence, that reveals the limitations of the theory of decoherence to solve the difficulties posed by optical isomerism and, in general, by quantum measurement. 相似文献
45.
Juan F. Navarro M.C. Martínez–Belda 《Mathematical Methods in the Applied Sciences》2020,43(5):2289-2300
In the N-body ring problem, we investigate the motion of a massless body interacting with N bodies of equal masses at the vertices of a regular polygon that rotates around a central mass. In this paper, we analyze the use of different surfaces of section in the numerical exploration of the escape in the N-body ring problem in order to get some conclusions about the geometry of the basins of escape in the corresponding configuration spaces. 相似文献
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Methods of synthesis of alkyl 2-(1-t-butylperoxyalkyl)propenoates and ethyl 2-t-butylperoxymethylbut-2-enoate are developped through the nucleophilic substitution of t-butylperoxylate anion towards various allylic derivatives prepared from alkyl 2-hydroxymethylalk-2-enoates and ethyl 2-(1-hydroxyethyl)propenoate. 相似文献
49.
The search for renewable sources of energy has led to renewed interests on the biochemical route for the production of butanol. Butanol production suffers from several drawbacks, mainly caused by butanol inhibition to the butanol-producing microorganism which makes it economically uncompetitive against the chemical process. One possible solution proposed is the in situ recovery of acetone–butanol–ethanol (ABE). Among the in situ recovery options, membrane processes like pervaporation have a great potential. Thus, the effects of temperature, feed concentration, and ultrasound irradiation on permeate concentration and permeation flux for the recovery of butanol/ABE by pervaporation from aqueous solutions were investigated in this study. In the butanol–water system, permeate butanol concentration as well as flux increased with an increase in temperature and butanol feed concentration. When pervaporation studies with ABE–water mixture were carried out at 60 °C for 2, 4, 8, 16, and 24 h, pervaporation profile revealed an optimal permeate concentration as well as permeation flux. Applications of ultrasound irradiation on pervaporation improved permeate concentration by about 23 g/L for both butanol and ABE. Ultrasound irradiation also improved butanol and ABE mass permeation flux by about 13 and 11 %, respectively. 相似文献
50.
Dr. Pablo Trigo‐Mouriño Dr. M. Carmen de la Fuente Dr. Roberto R. Gil Dr. Víctor M. Sánchez‐Pedregal Dr. Armando Navarro‐Vázquez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(44):14989-14997
The conformational state of 8‐chloro‐1‐methyl‐2,3,4,5‐tetrahydro‐1H‐3‐benzazepine hydrochloride (lorcaserin) in water has been determined on the basis of one‐bond and long‐range C? H residual dipolar coupling (RDC) data along with DFT computations and 3JHH coupling‐constant analysis. According to this analysis, lorcaserin exists as a conformational equilibrium of two crown‐chair forms, of which the preferred conformation has the methyl group in an equatorial orientation. 相似文献