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131.
In an earlier article, the authors proved that limits of convergent graph sequences can be described by various structures, including certain 2‐variable real functions called graphons, random graph models satisfying certain consistency conditions, and normalized, multiplicative and reflection positive graph parameters. In this article we show that each of these structures has a related, relaxed version, which are also equivalent. Using this, we describe a further structure equivalent to graph limits, namely probability measures on countable graphs that are ergodic with respect to the group of permutations of the nodes. As an application, we prove an analogue of the Positivstellensatz for graphs: we show that every linear inequality between subgraph densities that holds asymptotically for all graphs has a formal proof in the following sense: it can be approximated arbitrarily well by another valid inequality that is a “sum of squares” in the algebra of partially labeled graphs. © 2011 Wiley Periodicals, Inc. J Graph Theory 相似文献
132.
Z Mucsi M Porcs-Makkay G Simig IG Csizmadia B Volk 《The Journal of organic chemistry》2012,77(17):7282-7290
The routine prediction of the reactivity of a complex, multifunctional molecule is a challenging and time-consuming procedure. In the last step of the synthesis of the well-known drug substance tenidap, a nonexpected difference was observed between the reactivities of two closely related carbamate moieties, the N-ethoxycarbonyl and the N-phenoxycarbonyl group. A detailed kinetic study, necessitating a significant computational effort, is described in the present paper for this reaction step. On the other hand, the systems chemistry concept, by analyzing the details of the electronic structure and the connections between functional groups in a fast and simple way, is also able to answer this question using various "-icity" parameters (aromaticity, carbonylicity, olefinicity). The complete systems chemistry approach involves all these conjugativicity parameters, while its further simplified version is based on only one key parameter, which is carbonylicity in the present case. The above methods were compared in terms of their predictive power. The results show that the systems chemistry concept, even its one-parameter version, is applicable for the characterization of this challenging reactivity issue. 相似文献
133.
Márton Balázs 《Journal of statistical physics》2001,105(3-4):511-524
Considering the hydrodynamical limit of some interacting particle systems leads to hyperbolic differential equation for the conserved quantities, e.g., the inviscid Burgers equation for the simple exclusion process. The physical solutions of these partial differential equations develop discontinuities, called shocks. The microscopic structure of these shocks is of much interest and far from being well understood. We introduce a domain growth model in which we find a stationary (in time) product measure for the model, as seen from a defect tracer or second class particle, traveling with the shock. We also show that under some natural assumptions valid for a wider class of domain growth models, no other model has stationary product measure as seen from the moving defect tracer. 相似文献
134.
We have investigated the 20 nm p-type double gate junctionless tunnel field effect transistor (P-DGJLTFET) and the impact of variation of different device parameters on the performance parameters of the P-DGJLTFET is discussed. We achieved excellent results of different performance parameters by taking the optimized device parameters of the P-DGJLTFET. Together with a high-k dielectric material (TiO2) of 20 nm gate length, the simulation results of the P-DGJLTFET show excellent characteristics with a high IoN of ~ 0.3 mA/μm, a low/OFF of ~ 30 fA/μm, a high ION/IOFF ratio of ~ 1×10^10, a subthreshold slope (SS) point of ~ 23 mV/decade, and an average SS of ~ 49 mV/decade at a supply voltage of -1 V and at room temperature, which indicates that PDGJLTFET is a promising candidate for sub-22 nm technology nodes in the implementation of integrated circuits. 相似文献
135.
Subhajit Bal Chandranath Ghosh Tapan Ghosh Ratheesh K. Vijayaraghavan Dibyendu Das 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(32):13608-13612
Hydrophobic collapse plays crucial roles in protein functions, from accessing the complex three-dimensional structures of native enzymes to the dynamic polymerization of non-equilibrium microtubules. However, hydrophobic collapse can also lead to the thermodynamically downhill aggregation of aberrant proteins, which has interestingly led to the development of a unique class of soft nanomaterials. There remain critical gaps in the understanding of the mechanisms of how hydrophobic collapse can regulate such aggregation. Demonstrated herein is a methodology for non-equilibrium amyloid polymerization through mutations of the core sequence of Aβ peptides by a thermodynamically activated moiety. An out of equilibrium state is realized because of the negative feedback from the transiently formed cross-β amyloid networks. Such non-equilibrium amyloid nanostructures were utilized to access temporal control over its electronic properties. 相似文献
136.
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
137.
Balázs Szendrői 《Communications in Mathematical Physics》2003,238(1-2):35-51
Enhanced gauge symmetry appears in Type II string theory (as well as F- and M-theory) compactified on Calabi–Yau manifolds
containing exceptional divisors meeting in Dynkin configurations. It is shown that in many such cases, at enhanced symmetry
points in moduli a braid group acts on the derived category of sheaves of the variety. This braid group covers the Weyl group
of the enhanced symmetry algebra, which itself acts on the deformation space of the variety in a compatible way. Extensions
of this result are given for nontrivial B-fields on K3 surfaces, explaining physical restrictions on the B-field, as well as for elliptic fibrations. The present point of view also gives new evidence for the enhanced gauge symmetry
content in the case of a local A
2n
-configuration in a threefold having global ℤ/2 monodromy.
Received: 28 October 2002 / Accepted: 9 December 2002
Published online: 28 May 2003
Communicated by R.H. Dijkgraaf 相似文献
138.
139.
Sharpless kinetic asymmetric epoxidation on (±)-2-(l-hydroxyethyl)-5,8-dimethoxy-3,4-dihydronaphthalene (8) followed by LAH reduction gave R-2-(S-l-hydroxyethyl)-2hydroxy-5,8-dimethoxy-1,2,3,4-tetrahydronaphthalene and the undesired antipode. The former was converted to R-(-)-2-acetyl-2 hydroxy-5,8-dimethoxy-l,2,3,4-tetrahydronapthalen[R-(-)-5],while the latter was epimerized and recycled. R-(-)-5 has been exploited for the synthesis of(+)-4-demethoxydaunomycin 相似文献
140.
The notion of common cause closedness of a classical, Kolmogorovian probability space with respect to a causal independence relation between the random events is defined, and propositions are presented that characterize common cause closedness for specific probability spaces. It is proved in particular that no probability space with a finite number of random events can contain common causes of all the correlations it predicts; however, it is demonstrated that probability spaces even with a finite number of random events can be common cause closed with respect to a causal independence relation that is stronger than logical independence. Furthermore it is shown that infinite, atomless probability spaces are always common cause closed in the strongest possible sense. Open problems concerning common cause closedness are formulated and the results are interpreted from the perspective of Reichenbach's Common Cause Principle (RCCP). 相似文献