Banach空间不连续的脉冲微分-积分方程的解与迭代解

本文通过建立一个比较结果,应用不动点定理与上、下解方法,讨论了Ｂａｎａｃｈ空间含间断项的一阶混合型脉冲微分－积分方程初值问题的最大解和最小解,并在非线性项满足Ｃａｒａｔｈｅｏｄｏｒｙ条件时获得了解的迭代,推广改进了某些文献中的相应结果．     

First enantioselective catalyst based on a chiral terpyridine: synthesis of new C2-symmetric 2,2′:6′,2′′-terpyridine ligands and copper-catalyzed enantioselective cyclopropanation of alkenes

New C₂-symmetric chiral 2,2′:6′,2′′-terpyridines were prepared from readily available homochiral materials. Copper complexes of these ligands were prepared in situ and their catalytic activities in cyclopropanations of alkenes with alkyl diazoacetate to give cyclopropyl esters were studied. In all cases, the cyclopropyl ester yields were excellent and enantioselectivities up to 94% ee were observed. Competition experiments revealed that electron-donating substituents on styrene accelerate the reaction. Hammett plot exhibited a good linearity with negative ρ⁺ value (−0.79).     

Synthesis of N-α-pyridylmethyl amino alcohols and application in catalytic asymmetric addition of diethylzinc to aromatic aldehydes

A series of novel chiral ligands 2a–2f were conveniently prepared from β-amino alcohols through a two-step reaction and applied to catalyze the enantioselective addition of diethylzinc to benzaldehyde. Among them, ligand 2c was found to show the best asymmetric induction and catalyze the reaction of various aromatic aldehydes to provide (R)-secondary alcohols in up to 98.3% ee.     

Multicriteria models for the allocation of design parameter targets

The allocation of process mean locations for design parameters is important in establishing the mean of a performance characteristic within performance limits. This is an especially difficult problem when there is a multivariate set of performance measures that are all functions of a common set of design parameters. We propose multicriteria models for the allocation of design parameters that either (1) attempt to minimize the deviation of performance measures from prespecified nominal values, or (2) attempt to place performance measure means well within tolerance ranges. Empirical comparisons with established procedures, via case studies and examples, are used to illustrate both the effectiveness of the proposed procedures as well as the degree of flexibility that these procedures possess for modeling a wide range of product/process design decision environments.     

Optically active cyclic poly(ether sulfone)s based on chiral 1,1′-bi-2-naphthol

Optically active cyclic poly(ether sulfone)s are prepared from 4-fluorophenyl sulfone and (R)- or (S)-1,1′-bi-2-naphthol. The measurement of MALDI-TOF MS shows that the product is composed of a series of cyclic and linear oligomers where the repeating unit number (n) is from 2 to 12, from which the cyclic dimers (n=2), and cyclic trimer (n=3) have been separated from their homologous compounds by TLC successfully. Specific optical rotation [α]_D²⁵ is −583.0 for (R)-cyclic dimer, +588.0 for (S)-cyclic dimer, +22.7 for (R)-cyclic trimer, and −20.3 for (S)-cyclic trimer. Their properties are also determined by other methods, such as ¹H NMR and CD etc.     

A note on the homogeneous balance method

Based on the idea of the homogeneous balance method, a simple and efficient method is proposed for obtaining exact solutions of nonlinear partial differential equations. Some equations are investigated by this means and new solitary wave solutions or singular traveling wave solutions are found.     

Varying the Unruh temperature in integrable quantum field theories

A computational scheme is developed to determine the response of a quantum field theory (QFT) with a factorized scattering operator under a variation of the Unruh temperature. To this end a new family of integrable systems is introduced, obtained by deforming such QFTs in a way that preserves the bootstrap S-matrix. The deformation parameter β plays the role of an inverse temperature for the thermal equilibrium states associated with the Rindler wedge, β = 2π being the QFT value. The form factor approach provides an explicit computational scheme for the β ≠ 2π systems, enforcing in particular a modification of the underlying kinematical arena. As examples deformed counterparts of the Ising model and the sinh-Gordon model are considered.