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101.
采用Eclipse图形建模框架(Graphical Modeling Framework,GMF)技术构建了一个图形化磁共振脉冲序列设计软件.软件具备所见即所得的特点,用户使用拖放方式所画出的脉冲序列与教科书和参考文献上的脉冲序列几乎一样.软件支持核磁共振(Nuclear Magnetic Resonance,NMR)波谱和磁共振成像(Magnetic Resonance Imaging,MRI)的脉冲序列设计,同时提供实验参数管理模块,实现脉冲序列基础上的NMR实验设计和执行预览.得益于GMF完善的模型-视图-控制器模式和强大的代码生成能力,软件开发周期大幅度缩短、扩展能力大幅度提高. 相似文献
102.
Yun Bai Huaiyu Wang Jianghua He Yuetao Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(28):11710-11716
An immortal N-(diphenylphosphanyl)-1,3-diisopropyl-4,5-dimethyl-1,3-dihydro-2H-imidazol-2-imine/diisobutyl (2,6-di-tert-butyl-4-methylphenoxy) aluminum (P(NIiPr)Ph2/(BHT)AliBu2)-based frustrated Lewis pair (FLP) polymerization strategy is presented for rapid and scalable synthesis of the sequence-controlled multiblock copolymers at room temperature. Without addition of extra initiator or catalyst and complex synthetic procedure, this method enabled a tripentacontablock copolymer (n=53, k=4, dpn=50) to be achieved with the highest reported block number (n=53) and molecular weight (Mn=310 kg mol−1) within 30 min. More importantly, this FLP polymerization strategy provided access to the multiblock copolymers with tailored properties by precisely adjusting the monomer sequence and block numbers. 相似文献
103.
104.
Extended Fisher-Kolmogorov系统的渐近吸引子 总被引:2,自引:0,他引:2
考虑了ExtendedFisher-Kolmogorov系统的解的长时间行为,构造了一个有限维解序列即该系统的渐近吸引子,证明了它在长时间后无限趋于方程的整体吸引子,并给出了渐近吸引子的维数估计. 相似文献
105.
He Wansheng 《Annals of Differential Equations》2005,21(3):300-304
In this paper, we study the global stability, and the periodic character of the rational recursive sequence. We show that the positive equilibrium of the sequence is a global attractor with a basin which depends on certain conditions posed on the coefficients. 相似文献
106.
Daniel Erman 《Journal of Combinatorial Theory, Series A》2011,118(2):396-402
Duistermaat and van der Kallen show that there is no nontrivial complex Laurent polynomial all of whose powers have a zero constant term. Inspired by this, Sturmfels poses two questions: Do the constant terms of a generic Laurent polynomial form a regular sequence? If so, then what is the degree of the associated zero-dimensional ideal? In this note, we prove that the Eulerian numbers provide the answer to the second question. The proof involves reinterpreting the problem in terms of toric geometry. 相似文献
107.
In this short note, we focus on self-inverse Sheffer sequences and involutions in the Riordan group. We translate the results of Brown and Kuczma on self-inverse sequences of Sheffer polynomials to describe all involutions in the Riordan group. 相似文献
108.
Klaus Pinn 《Complexity》1999,4(3):41-46
A number of observations are made on Hofstadter's integer sequence defined by Q(n) = Q(n − Q(n − 1)) + Q(n − Q(n − 2)), for n > 2, and Q(1) = Q(2) = 1. On short scales, the sequence looks chaotic. It turns out, however, that the Q(n) can be grouped into a sequence of generations. The k‐th generation has 2k members that have “parents” mostly in generation k − 1 and a few from generation k − 2. In this sense, the sequence becomes Fibonacci type on a logarithmic scale. The variance of S(n) = Q(n) − n/2, averaged over generations, is ≅2αk, with exponent α = 0.88(1). The probability distribution p*(x) of x = R(n) = S(n)/nα, n ≫ 1, is well defined and strongly non‐Gaussian, with tails well described by the error function erfc. The probability distribution of xm = R(n) − R(n − m) is given by pm(xm) = λm p*(xm/λm), with λm → √2 for large m. © 1999 John Wiley & Sons, Inc. 相似文献
109.
Osamu Iyama 《Advances in Mathematics》2011,226(1):1
The concept of cluster tilting gives a higher analogue of classical Auslander correspondence between representation-finite algebras and Auslander algebras. The n-Auslander–Reiten translation functor τn plays an important role in the study of n-cluster tilting subcategories. We study the category Mn of preinjective-like modules obtained by applying τn to injective modules repeatedly. We call a finite-dimensional algebra Λ n-complete if for an n-cluster tilting object M. Our main result asserts that the endomorphism algebra EndΛ(M) is (n+1)-complete. This gives an inductive construction of n-complete algebras. For example, any representation-finite hereditary algebra Λ(1) is 1-complete. Hence the Auslander algebra Λ(2) of Λ(1) is 2-complete. Moreover, for any n?1, we have an n-complete algebra Λ(n) which has an n-cluster tilting object M(n) such that Λ(n+1)=EndΛ(n)(M(n)). We give the presentation of Λ(n) by a quiver with relations. We apply our results to construct n-cluster tilting subcategories of derived categories of n-complete algebras. 相似文献
110.
In this paper, using the difference operator of order m and an Orlicz function, we introduce and examine some classes of sequences of fuzzy numbers. We give the relations between the strongly Cesàro type convergence and statistical convergence in these spaces. Furthermore, we study some of their properties like completeness, solidity, symmetricity, etc. We also give some inclusion relations related to these classes. 相似文献