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81.
The present paper deals with an original time-domain approach applied to outdoor sound propagation under meteorological effects. The transmission line matrix method, based on the Huygens’ principle, had already been validated over impedant grounds and complex topography. The presented formulation proposes to take into account meteorological effects (wind speed and temperature) through the relative sound speed. The necessary wavefront direction is determined through the calculation of the averaged intensity vector direction. A good agreement is found between simulations of both the transmission line matrix and parabolic equation methods. A relevant use of the method is shown in the framework of environmental acoustics and initial applications are proposed in Part 2. 相似文献
82.
Expeditious Synthesis of Enantiopure,Orthogonally Protected Bis‐α‐Amino Acids (OPBAAs) and their Use in a Study of Nod1 Stimulation 下载免费PDF全文
Po‐Ting Chen Cheng‐Kun Lin Chih‐Ju Tsai Dr. Duen‐Yi Huang Fu‐Yao Nien Dr. Wan‐Wan Lin Prof. Dr. Wei‐Chieh Cheng 《化学:亚洲杂志》2015,10(2):474-482
A convenient approach towards the synthesis of orthogonally protected chiral bis‐α‐amino acids (OPBAAs) is described. The key transformations include: (1) a highly stereoselective conjugation (alkylation) of the Schöllkopf bis‐lactim ethers and oxazolidinyl alkyl halides to build a backbone skeleton; and (2) our orthogonal protection strategy. A series of enantiopure OPBAAs bearing a variety of alkyl chain as a spacer; two stereogenic centers; and three protecting groups were prepared as examples. These versatile molecules were applied to the synthesis of biologically interesting di‐ or tri‐peptide analogues, including chiral iE‐meso‐DAP and A‐iE‐meso‐DAP, for the study of Nod1 activation in the innate immune response. 相似文献
83.
O. Mali 《Numerical Functional Analysis & Optimization》2017,38(1):58-79
In this article, functional type a posteriori error estimates are presented for a certain class of optimal control problems with elliptic partial differential equation constraints. It is assumed that in the cost functional the state is measured in terms of the energy norm generated by the state equation. The functional a posteriori error estimates developed by Repin in the late 1990s are applied to estimate the cost function value from both sides without requiring the exact solution of the state equation. Moreover, a lower bound for the minimal cost functional value is derived. A meaningful error quantity coinciding with the gap between the cost functional values of an arbitrary admissible control and the optimal control is introduced. This error quantity can be estimated from both sides using the estimates for the cost functional value. The theoretical results are confirmed by numerical tests. 相似文献
84.
On the existence of positive least energy solutions for a coupled Schrödinger system with critical exponent 下载免费PDF全文
Hongyu Ye 《Mathematical Methods in the Applied Sciences》2017,40(4):1032-1043
In this paper, we consider the following coupled Schrödinger system with critical exponent: where is a smooth bounded domain, λ > 0,μ≥0, and . Under certain conditions on λ and μ, we show that this problem has at least one positive least energy solution. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
85.
A new variant of the Adaptive Cross Approximation (ACA) for approximation of dense block matrices is presented. This algorithm can be applied to matrices arising from the Boundary Element Methods (BEM) for elliptic or Maxwell systems of partial differential equations. The usual interpolation property of the ACA is generalised for the matrix valued case. Some numerical examples demonstrate the efficiency of the new method. The main example will be the electromagnetic scattering problem, that is, the exterior boundary value problem for the Maxwell system. Here, we will show that the matrix valued ACA method works well for high order BEM, and the corresponding high rate of convergence is preserved. Another example shows the efficiency of the new method in comparison with the standard technique, whilst approximating the smoothed version of the matrix valued fundamental solution of the time harmonic Maxwell system. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
86.
Dr. Yifeng Chen David Huang Yizhou Zhao Prof. Dr. Timothy R. Newhouse 《Angewandte Chemie (International ed. in English)》2017,56(28):8258-8262
The telescoping of allyl-palladium catalyzed ketone dehydrogenation with organocuprate conjugate addition chemistry allows for the introduction of aryl, heteroaryl, vinyl, acyl, methyl, and other functionalized alkyl groups chemoselectively to a wide variety of unactivated ketone compounds via their enone counterparts. The compatibility of the dehydrogenation conditions additionally allows for efficient trapping of the intermediate enolate with various electrophiles. The utility of this approach is demonstrated by comparison to several previously reported multistep sequences. 相似文献
87.
Alexander A. Kirichok Dr. Iryna Shton Dr. Maria Kliachyna Dr. Iryna Pishel Dr. Pavel K. Mykhailiuk 《Angewandte Chemie (International ed. in English)》2017,56(30):8865-8869
The 2-substituted piperidine core is found in drugs (18 FDA-approved drugs), however, their spirocyclic analogues remain unknown. Described here is the synthesis of spirocyclic analogues for 2-substituted piperidines and a demonstration of their validation in drug discovery. 相似文献
88.
《Angewandte Chemie (International ed. in English)》2017,56(33):9670-9679
During the last 40 years, researchers investigating photoinitiated cationic polymerizations have delivered tremendous success in both industrial and academic settings. A myriad of photoinitiating systems have been developed, thus allowing polymerization of a broad array of monomers (e.g., epoxides, vinyl ethers, alkenes, cyclic ethers, and lactones) under practical, inexpensive, and environmentally benign conditions. More recently, owing to progress in photoredox catalysis, photocontrolled cationic polymerization has emerged as a means to precisely regulate polymer chain growth. This Minireview provides a concise historical perspective on cationic polymerization induced by light and discusses the latest advances in both photoinitiated and photocontrolled processes. The latter are exciting new directions for the field that will likely impact industries ranging from micropatterning to the synthesis of complex biomaterials and sequence‐controlled polymers. 相似文献
89.
《Angewandte Chemie (International ed. in English)》2017,56(16):4612-4616
The treatment of various N‐morpholino amides with TMPZnCl⋅LiCl (TMP=2,2,6,6‐tetramethylpiperidyl) and Mg(OPiv)2 in THF at 25 °C provides solid zinc enolates with enhanced air and moisture stability (t 1/2 in air: 1–3 h) after solvent evaporation. These enolates undergo Pd‐ and Cu‐catalyzed cross‐couplings with (hetero)aryl bromides as well as allylic and benzylic halides. The arylated N‐morpholino amides were converted into various ketones by LaCl3⋅2 LiCl mediated acylation with Grignard reagents. The new, solid enolates were used to prepare a potent anti‐breast‐cancer drug candidate in six steps and 23 % overall yield. 相似文献
90.