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In this series of papers, we introduce τ-categories, which are additive categories with some kind of Auslander–Reiten sequences.
We apply them to study the category of lattices over orders. In this first paper, we study minimal projective resolutions
in functor categories over τ-categories. Then we give a structure theorem of completely graded τ-categories using mesh categories.
Presented by K. Roggenkamp
Mathematics Subject Classifications (2000) primary 16G30; secondary 16E65, 16G70, 18E05.
Osamu Iyama: Current address: Department of Mathematics, University of Hyogo, Himeji, 671-2201, Japan. e-mail: iyama@sci.u-hyogo.ac.jp. 相似文献
64.
R. Jantas G. Janowska H. Szocik S. Połowiński 《Journal of Thermal Analysis and Calorimetry》2000,60(2):371-376
Differential scanning calorimetry and thermogravimetry were used to examine the thermal behaviour of the multimonomers poly(2-methacryloyloxyethyl
methacrylate) and poly(2-acryloyloxyethyl methacrylate), of the ladder polymers prepared by the template polymerization of
these multimonomers, and of a linear analogue of the ladder polymers, poly(2-butyrylethyl methacrylate). The results obtained
show that only one of the ladder polymers has a considerably higher thermal stability than that of their linear analogue.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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66.
Zi-Di Yu Yang Lu Prof. Jie-Yu Wang Prof. Jian Pei 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(69):16194-16205
In the past few decades, conjugated polymers have aroused extensive interest in organic electronic applications. The electrical performance of conjugated polymers has a close relationship with their backbone conformation. The conformation of the polymer backbone strongly affects the πelectron delocalization along polymer chains, the energy band gap, interchain interactions, and further affects charge transport properties. To realize a rigid coplanar backbone that usually possesses efficient intrachain charge transport properties and enhanced π–π stackings, such conformation control becomes a useful strategy to achieve high-performance (semi)conducting polymers. This minireview summarizes the most important polymer structures through conformation control at the molecular level, and then divides these rigid coplanar conjugated polymers into three categories: 1) noncovalent interactions locked conjugated polymers; 2) double-bond linked conjugated polymers; 3) ladder conjugated polymers. The effect of the conformation control on physical nature, optoelectronic properties, and their device performance is also discussed, as well as the challenges of chemical synthesis and structural characterization. 相似文献
67.
It is well known that the presence of outlier events can overestimate or underestimate the overall reserve when using the chain-ladder method. The lack of robustness of loss reserving estimators leads to the development of this paper. The appearance of outlier events (including large claims—catastrophic events) can offset the result of the ordinary chain ladder technique and perturb the reserving estimation. Our proposal is to apply robust statistical procedures to the loss reserving estimation, which are insensitive to the occurrence of outlier events in the data. This paper considers robust log-linear and ANOVA models to the analysis of loss reserving by using different type of robust estimators, such as LAD-estimators, M-estimators, LMS-estimators, LTS-estimators, MM-estimators (with initial S-estimate) and Adaptive-estimators. Comparisons of these estimators are also presented, with application of a well known data set. 相似文献
68.
Albert Sung Soo Lee Seung‐Sock Choi He Seung Lee Hyeon Yeol Jeon Kyung‐Youl Baek Seung Sang Hwang 《Journal of polymer science. Part A, Polymer chemistry》2012,50(21):4563-4570
A series of inorganic–organic hybrid block copolymers were synthesized via atom transfer radical polymerization using a fully condensed, ladder‐like structured polyphenylsilsesquioxane end‐functionalized macroinitiator. The inorganic portion, ladder‐like polyphenylsilsesquioxane, was synthesized in a one‐batch, base‐catalyzed system, whereas organic hard and soft monomers, styrene, and n‐butyl acrylate, were polymerized and copolymerized on the ends of the linear, inorganic backbone. Synthesized hybrid diblock, triblock, and random copolymers were characterized by 1H NMR, 29Si NMR, gel permeation chromatography, static light scattering, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. Hybrid block copolymers were well‐defined with low polydispersity (<1.4) and exhibited enhanced thermal properties in the form of increased glass transition and degradation onset temperatures over their organic analogues.© 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
69.
Magnetic properties of three-leg antiferromagnetic Heisenberg spin-1/2 ladders with different dimerization patterns have been studied using the bond mean-field theory. Our results show that rung-columnar ladders are thermodynamically stable states for large rung-to-leg coupling ratios. Magnetization curves of leg-columnar and leg-staggered ladders always exhibit 0- and 2/3-magnetization plateaus, which do not appear in rung-columnar and rung-staggered ladders. In leg-dimerized ladders, the formation of spin dimers in the three legs results in the appearance of the 0- and 2/3-magnetization plateaus. Spin configuration in the 2/3-magnetization plateau can be understood from the mean-field bond parameters. 相似文献
70.
A. A. S. El Khaldy J. R. Durig 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):227-236
Abstract Mixed chloride dialkyl and alkylenedithiophosphates of ruthenium (III). RuC13-n|(S2P(OR)2|n (R = Prn, and Ph) and RuCl3-n,[S2 POGO]n G =-CMe2CMe2,- CH2CMe2CH2-, -CH2CEt2CH2-. and -CMe2CH2CHMe-, n = 1,2 have been synthesized for the first time by the reactions of ruthenium trichloride with ammonium dialkyl and alkylenedithiophosphate or alternatively by disproportionation reactions of ruthenium trichloride with ruthenium tris(dialkyl and alkylenedithiophosphates) in different stoichiometric ratios in benzene. These new complexes have been characterized by elemental analysis, molecular weight determinations, as well as IR and NMR (1H and 31P) data. Chelated structures with bidentate dialkyl and alkylenedithiophosphates groups have been proposed for all these derivatives. 相似文献