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141.
Relying on the resolvent operator method and using Nadler's theorem, we suggest and analyze a class of iterative schemes for solving multivalued quasi-variational inclusions. In fact, by considering problems involving composition of mutivalued operators and by replacing the usual compactness condition by a weaker one, our result can be considered as an improvement and a significant extension of previously known results in this field.  相似文献   
142.
An efficient and general low-cost method is described to obtain chiral Nβ-Boc protected α-Nα-hydrazino diester building-blocks (orthogonally and non-orthogonally protected diesters) on multi-gram scale (30 mmol) using two successive SN2 reactions. This method is also convenient for the introduction of both polar and nonpolar side chains on the Nα-atom and represents an inexpensive and attractive alternative compared to the more expensive method using commercial oxaziridine reagents for N-amination of α-amino acids.  相似文献   
143.
Polymers containing o‐nitrobenzyl esters are promising for preparation of light sensitive materials. o‐Nitrobenzyl methacrylate has already been polymerized by controlled ATRP or RAFT. Unfortunately, the radical polymerization of o‐nitrobenzyl acrylate (NBA) was not controlled until now due to inhibition and retardation effects coming from the nitro‐aromatic groups. Recent developments in the Single Electron Transfer–Living Radical Polymerization (SET–LRP) provide us an access to control this NBA polymerization and living character of this NBA SET–LRP is demonstrated. Effects of CuBr2 and ligand concentrations, as well as Cu(0) wire length on SET–LRP kinetics are shown presently. A first‐order kinetics with respect to the NBA concentration is observed after one induction period. SET–LRP proceeds with a linear evolution of molecular weight and a narrow distribution. High initiation efficiency close to 1 and high chain‐end functionality (~93%) are reached. Chain extension of poly(o‐nitrobenzyl acrylate) is realized with methyl acrylate (MA) to obtain well defined poly(o‐nitrobenzyl acrylate)‐b‐poly(methyl acrylate) (PNBA‐b‐PMA). Finally, light‐sensitive properties of PNBA are checked upon UV irradiation. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2192–2201  相似文献   
144.
Ohne ZusammenfassungDiese Arbeit entstand 1964 an der Technischen Hochschule Karlsruhe, wohin der zweite Autor als Gastdozent von den Bell Telephone Laboratories beurlaubt war.  相似文献   
145.
Chemical control of the DNA light switch: cycling the switch ON and OFF   总被引:2,自引:0,他引:2  
The emission of the DNA light-switch complex [Ru(bpy)2(tpphz)]2+ (bpy = 2,2'-bipyridine, tpphz = tetrapyrido[3,2-a:2',3'-c:3' ',2' '-h:2' ',3' '-j]phenazine) can be reversibly turned ON and OFF over several cycles. The tpphz and taptp (taptp = 4,5,9,18-tetraazaphenanthreno[9,10-b] triphenylene) ligands in [Ru(bpy)2(tpphz)]2+ and [Ru(bpy)2(taptp)]2+, respectively, intercalate between the DNA bases, and a 50-fold increase in emission intensity of [Ru(bpy)2(tpphz)]2+ is observed upon DNA intercalation. The [Ru(bpy)2(tpphz)]2+ DNA light switch can be turned OFF statically in the presence of Co2+, Ni2+, and Zn2+, and the emission can be fully restored by the addition of EDTA. Cycling of the DNA light switch OFF and ON can be accomplished through the successive introduction of Co2+ and EDTA, respectively, to solutions of DNA-bound [Ru(bpy)2(tpphz)]2+. Owing to the absence of additional coordination sites, the emission of DNA-intercalated [Ru(bpy)2(taptp)]2+ is not quenched by transition metal ions in solution. To our knowledge, this work presents the first example of a reversible DNA light switch.  相似文献   
146.
A short and efficient protocol for the asymmetric synthesis of cis‐ and trans‐3,4‐dihydro‐2,4,8‐trihydroxynaphthalen‐1(2H)‐one ( 1 and 2 , resp.) is described, with a phthalide annulation as the key step. Introduction of a OH substituent at position 2 was performed by Sharpless dihydroxylation of a silyl enol ether or by means of an N‐sulfonyloxaziridine. The absolute configuration of each isomer was determined via Mosher‐ester derivatives. By comparison with previously recorded CD spectra of our natural sample, we established that the natural trans‐ and cis‐isomers from Ceratocystis fimbriata sp. platani were the (?)‐(2S,4S)‐isomer (?)‐ 2 and the (+)‐(2S,4R)‐isomer (+)‐ 1 , respectively.  相似文献   
147.
A mathematical model is presented which describes the diffusion of oxygen in absorbing tissue, and numerical solution of its partial differential equation is obtained by the finite difference equations. The diffusion with absorption model is associated with the process of a moving boundary which marks the furthest penetration of oxygen in the absorbing cylindrically shaped sections of tissue and also allows for an initial distribution of oxygen through the absorbing tissue. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
148.
Nonlinear Dynamics - This paper investigates the problem of sensor fault estimation for systems with monotone nonlinearities and unknown inputs. To the best of our knowledge, such a particular...  相似文献   
149.
X‐ray photon correlation spectroscopy was used to probe the diffusive dynamics of colloidal particles in a shear flow. Combining X‐ray techniques with microfluidics is an experimental strategy that reduces the risk of X‐ray‐induced beam damage and also allows time‐resolved studies of processes taking place in flow cells. The experimental results and theoretical predictions presented here show that in the low shear limit for a `transverse flow' scattering geometry (scattering wavevector q perpendicular to the direction of flow) the measured relaxation times are independent of the flow rate and determined only by the diffusive motion of the particles. This is not generally valid and, in particular, for a `longitudinal flow' ( q ∥ flow) scattering geometry the relaxation times are strongly affected by the flow‐induced motion of the particles. The results here show that the Brownian diffusion of colloidal particles can be measured in a flowing sample and that, up to flux limitations, the experimental conditions under which this is possible are easier to achieve at higher values of q.  相似文献   
150.
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