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31.
32.
Zusammenfassung Chromatographische Versuche zeigen, daß die Zwischenprodukte der Kjeldahlisierung des Anilins mit denen der Anilinschwarz-Bildung verwandt sind. Die Elementaranalyse von Polymerisationsprodukten dieser Zwischenstoffe weist darauf hin, daß es sich um sulfonierte Oxyemeraldine handelt. Kinetische Versuche und Überlegungen führen zu dem Ergebnis, daß alle diese Zwischenstufen erst durchlaufen werden, nachdem Anilin zu Sulfanilsäure sulfoniert worden ist, wobei ein der weiteren Oxydation vorgelagertes Gleichgewicht erreicht wird.
Emil Abel zum 80. Geburtstag zugeeignet. 相似文献
33.
The colored Jones function of a knot is a sequence of Laurent polynomials that encodes the Jones polynomial of a knot and its parallels. It has been understood in terms of representations of quantum groups and Witten gave an intrinsic quantum field theory interpretation of the colored Jones function as the expectation value of Wilson loops of a 3-dimensional gauge theory, the Chern–Simons theory. We present the colored Jones function as an evaluation of the inverse of a non-commutative fermionic partition function. This result is in the form familiar in quantum field theory, namely the inverse of a generalized determinant. Our formula also reveals a direct relation between the Alexander polynomial and the colored Jones function of a knot and immediately implies the extensively studied Melvin–Morton–Rozansky conjecture, first proved by Bar–Natan and the first author about 10 years ago. Our results complement recent work of Huynh and Le, who also give a non-commutative formulae for the colored Jones function of a knot, starting from a non-commutative formula for the R matrix of the quantum group
; see Huynh and Le (in math.GT/0503296). 相似文献
34.
Stavros Iliadis 《Topology and its Applications》2010,157(17):2646-2658
In this paper by a spectrum of mappings we mean a morphism of spectra of spaces. However, using the notion of a mapping of mappings, we give the definition of a spectrum of mappings similar to that of a spectrum of spaces. In this case, the formulations of the given results are also similar to the formulations of the corresponding results concerning the spectra of spaces.For the spectra of mappings we define the notion of a τ-spectrum of mappings factorizing in a special sense and prove a version of the Spectral Theorem for such spectra. Furthermore, to a given indexed collection F of mapping we associate a τ-spectrum factorizing in the above special sense whose mappings are Containing Mappings for F constructed in Iliadis (2005) [4]. These associated τ-spectra and the corresponding version of the Spectral Theorem imply that for a given indexed collection F of mappings any so-called “natural” τ-spectrum for F factorizing in the special sense contains a cofinal and τ-closed subspectrum whose mappings are Containing Mapping for F. Thus, Containing Mappigs for F appear here without any concrete construction. The associated τ-spectra are used also in order to define and characterize the so-called second-type saturated classes of mappings (which are “saturated” by universal elements). 相似文献
35.
We study the generalized Galois numbers which count flags of length r in N-dimensional vector spaces over finite fields. We prove that the coefficients of those polynomials are asymptotically Gaussian normally distributed as N becomes large. Furthermore, we interpret the generalized Galois numbers as weighted inversion statistics on the descent classes of the symmetric group on N elements and identify their asymptotic limit as the Mahonian inversion statistic when r approaches ∞. Finally, we apply our statements to derive further statistical aspects of generalized Rogers–Szeg? polynomials, reinterpret the asymptotic behavior of linear q-ary codes and characters of the symmetric group acting on subspaces over finite fields, and discuss implications for affine Demazure modules and joint probability generating functions of descent-inversion statistics. 相似文献
36.
We consider arrays of size 2?×?2?×?2 and 2?×?2?×?2?×?2 over the fields with two and three elements. We use computer algebra to determine the canonical forms of these arrays with respect to the action of the semidirect product of general linear groups with the symmetric group. For each canonical form, we determine the size of its orbit and the rank of the arrays in its orbit. 相似文献
37.
Jiazhan Li Hanguang Zhang Widitha Samarakoon Weitao Shan David A. Cullen Stavros Karakalos Mengjie Chen Daming Gu Karren L. More Guofeng Wang Zhenxing Feng Zhenbo Wang Gang Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(52):19147-19156
FeN4 moieties embedded in partially graphitized carbon are the most efficient platinum group metal free active sites for the oxygen reduction reaction in acidic proton‐exchange membrane fuel cells. However, their formation mechanisms have remained elusive for decades because the Fe?N bond formation process always convolutes with uncontrolled carbonization and nitrogen doping during high‐temperature treatment. Here, we elucidate the FeN4 site formation mechanisms through hosting Fe ions into a nitrogen‐doped carbon followed by a controlled thermal activation. Among the studied hosts, the ZIF‐8‐derived nitrogen‐doped carbon is an ideal model with well‐defined nitrogen doping and porosity. This approach is able to deconvolute Fe?N bond formation from complex carbonization and nitrogen doping, which correlates Fe?N bond properties with the activity and stability of FeN4 sites as a function of the thermal activation temperature. 相似文献
38.
Stack the Bowls: Tailoring the Electronic Structure of Corannulene‐Integrated Crystalline Materials 下载免费PDF全文
Allison M. Rice Ekaterina A. Dolgopolova Brandon J. Yarbrough Gabrielle A. Leith Corey R. Martin Kenneth S. Stephenson Rebecca A. Heugh Amy J. Brandt Prof. Dr. Donna A. Chen Dr. Stavros G. Karakalos Dr. Mark D. Smith Prof. Dr. Kelsey B. Hatzell Dr. Perry J. Pellechia Prof. Dr. Sophya Garashchuk Prof. Dr. Natalia B. Shustova 《Angewandte Chemie (International ed. in English)》2018,57(35):11310-11315
We report the first examples of purely organic donor–acceptor materials with integrated π‐bowls (πBs) that combine not only crystallinity and high surface areas but also exhibit tunable electronic properties, resulting in a four‐orders‐of‐magnitude conductivity enhancement in comparison with the parent framework. In addition to the first report of alkyne–azide cycloaddition utilized for corannulene immobilization in the solid state, we also probed the charge transfer rate within the Marcus theory as a function of mutual πB orientation for the first time, as well as shed light on the density of states near the Fermi edge. These studies could foreshadow new avenues for πB utilization for the development of optoelectronic devices or a route for highly efficient porous electrodes. 相似文献
39.
Natural protective amyloids 总被引:1,自引:0,他引:1
Amyloidoses are a group of diseases including neurodegenerative diseases like Alzheimer's disease and also type II diabetes, spongiform encephalopathies and many others, believed to be caused by protein aggregation and subsequent amyloid fibril formation. However, occasionally, living organisms exploit amyloid fibril formation, a property inherent into amino acid sequences, and perform specific physiological functions from amyloids, in differing biological contexts. Some of these functional amyloids are natural protective amyloids. Here, we review recent evidence on silkmoth chorion protein synthetic peptide-analogues that documents the function of silkmoth chorion, the major component of the eggshell, a structure with extraordinary physiological and mechanical properties, as a natural protective amyloid. Also, we briefly discuss the reported function of other natural, protective amyloids like fish chorion, the protein Pmel17 which forms amyloid fibrils that act as templates and accelerate the covalent polymerization of reactive small molecules into melanin, the hydrophobins and the antifreeze protein from winter flounder. Molecular self-assembly is becoming an increasingly popular route to new supramolecular structures and molecular materials and the inspiration for such structures is commonly derived from self-assembling systems in biology. Therefore, a careful examination of these studies may set the basis for the exploration of new routes for the formation of novel biocompatible polymeric structures with exceptional physico-chemical properties, for potentially new biomedical and industrial applications. 相似文献
40.