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901.
The synthesis of new monodentate heterocyclic ligands 5-(4-pyridyl)-2-alkyltetrazole (L1a,b) and 4-[5-(2-alkyltetrazole)]aryl-4'-pyridinecarboxylate (L2a,b,c) containing two or three aromatic or heterocyclic rings (tetrazole, pyridine and benzene) and preparation of their corresponding silver(I) and palladium(II) complexes (Ia,b,c and IIa,b,c) are described. The thermal behaviour of the ligands and complexes was characterized by polarizing optical microscopy. The ligands and the complexes Ia,b,c and IIc showed no liquid crystalline phase. The complexes IIa,b showed mesomorphic behaviour, exhibiting smectic A enantiotropic mesomorphism X-ray diffraction measurements for complex Ia showed monodentate coordination of N-pyridine, and no coordination on the nitrogen atoms of the tetrazole ring. 相似文献
902.
This paper examines numerically the complex classical trajectories of the kicked rotor and the double pendulum. Both of these
systems exhibit a transition to chaos, and this feature is studied in complex phase space. Additionally, it is shown that
the short-time and long-time behaviours of these two PT-symmetric dynamical models in complex phase space exhibit strong qualitative similarities. 相似文献
903.
904.
Yael Berstein Hugo Maruri-Aguilar Shmuel Onn Eva Riccomagno Henry Wynn 《Annals of the Institute of Statistical Mathematics》2010,62(4):673-698
For a particular experimental design, there is interest in finding which polynomial models can be identified in the usual regression set up. The algebraic methods based on Gröbner bases provide a systematic way of doing this. The algebraic method does not, in general, produce all estimable models but it can be shown that it yields models which have minimal average degree in a well-defined sense and in both a weighted and unweighted version. This provides an alternative measure to that based on “aberration” and moreover is applicable to any experimental design. A simple algorithm is given and bounds are derived for the criteria, which may be used to give asymptotic Nyquist-like estimability rates as model and sample sizes increase. 相似文献
905.
Hugo Zollna 《Fresenius' Journal of Analytical Chemistry》1902,41(9):563
Ohne Zusammenfassung 相似文献
906.
Thiago Guerreiro Bruno Sanguinetti Hugo Zbinden Nicolas Gisin Antoine Suarez 《Physics letters. A》2012
We use heralded single photons to perform an antibunching experiment in which the clicks at the detectors are space-like separated events. The idea of such experiment dates back to the 5th Solvay conference, when it was proposed by Einstein as an expression of his concerns about quantum theory. 相似文献
907.
Chandra Chekuri Michael Bender 《Journal of Algorithms in Cognition, Informatics and Logic》2001,41(2):212
We give a new and efficient approximation algorithm for scheduling precedence-constrained jobs on machines with different speeds. The problem is as follows. We are given n jobs to be scheduled on a set of m machines. Jobs have processing times and machines have speeds. It takes pj/si units of time for machine i with speed si to process job j with processing requirement pj. Precedence constraints between jobs are given in the form of a partial order. If j k, processing of job k cannot start until job j's execution is completed. The objective is to find a non-preemptive schedule to minimize the makespan of the schedule. Chudak and Shmoys (1997, “Proceedings of the Eighth Annual ACM-SIAM Symposium on Discrete Algorithms (SODA),” pp. 581–590) gave an algorithm with an approximation ratio of O(log m), significantly improving the earlier ratio of
due to Jaffe (1980, Theoret. Comput. Sci.26, 1–17). Their algorithm is based on solving a linear programming relaxation. Building on some of their ideas, we present a combinatorial algorithm that achieves a similar approximation ratio but runs in O(n3) time. Our algorithm is based on a new and simple lower bound which we believe is of independent interest. 相似文献
908.
909.
Dr. Hugo Ludwig Fulda 《Monatshefte für Chemie / Chemical Monthly》1902,23(8):907-920
Ohne Zusammenfassung 相似文献
910.