Poly(7,16-dihydroheptacenes): a new type of obligate ladder polymer conformationally restricted to two dimensions

1982 ◽  
Vol 15 (4) ◽  
pp. 939-947 ◽  
Author(s):  
Vinod R. Sastri ◽  
Robert Schulman ◽  
David C. Roberts
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Noah F. Q. Yuan ◽  
Hiroki Isobe ◽  
Liang Fu

AbstractThe van Hove singularity in density of states generally exists in periodic systems due to the presence of saddle points of energy dispersion in momentum space. We introduce a new type of van Hove singularity in two dimensions, resulting from high-order saddle points and exhibiting power-law divergent density of states. We show that high-order van Hove singularity can be generally achieved by tuning the band structure with a single parameter in moiré superlattices, such as twisted bilayer graphene by tuning twist angle or applying pressure, and trilayer graphene by applying vertical electric field. Correlation effects from high-order van Hove singularity near Fermi level are also discussed.


2019 ◽  
pp. 75-79
Author(s):  
F. P. Vlasenko ◽  
Ye. V. Levcheniuk

Goal. To carry out socio-philosophical conceptualization of the phenomenon of information culture and cyberculture as the newest factors that determine the development of modern society and is characterized by intensification of processes of informatization and technologization. Theoret- ical basis. The authors have proved that the concepts of information culture and cyberculture are united in the sense of theoretical generalizations about understanding the essence of modern society (mass, virtual, global, information) and so on. It is substantiated that the main condition and consequence of the development of modern society is the emergence of information culture and cyberculture, which serve as the unity of value models of technical, information and technological levels of civilization, which simultaneously forms a new type of person, which is realized in two dimensions – real (physical, social) and virtual. Scientific novelty. It is substantiated that modern society is in a state of radical large-scale, systemic transformations, the consequence of which is a new stage of development of the relation "man – world", "man – society", "man – man". According to the authors, the determining factor is the development of information culture and cyberculture, which characterize the latest achievements in the development of modern science, technology, education. Conclusions. Progressive achievements of the technosphere of the late 20-th – early 21-st century created new conditions for the development of the society and a man. These advances have both complicated and simplified social connections and rela- tionships. This is how e-economy, e-education, e-government, e-tourism, and others have come into being and evolve. At the same time, culture is gaining a new dimension of development. It is transferred to the sphere of the Internet, network communities and is characterized as an information culture, cyberculture, forming a qualitatively new outlook with relevant values, norms, social roles and behaviors of modern man.


2018 ◽  
Vol 33 (34) ◽  
pp. 1845009 ◽  
Author(s):  
Henri Epstein ◽  
Ugo Moschella

Motivated by the study of soluble models of quantum field theory, we illustrate a new type of topological effect by comparing the constructions of canonical Klein–Gordon quantum fields on the two-dimensional de Sitter spacetime as opposed to its double covering. We show that while the commutators of the two fields coincide locally, the global topological differences make the theories drastically different. Many of the well-known features of de Sitter quantum field theory disappear. In particular, there is nothing like a Bunch–Davies vacuum. Correspondingly, even though the local horizon structure is the same for the two universes, there is no Hawking–Gibbons thermal state. Finally, there is no complementary series of fields.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2528 ◽  
Author(s):  
Eunice Espe ◽  
Vidyasagar Potdar ◽  
Elizabeth Chang

Smart grids are robust, self-healing networks that allow bidirectional propagation of energy and information within the utility grid. This introduces a new type of energy user who consumes, produces, stores and shares energy with other grid users. Such a user is called a “prosumer.” Prosumers’ participation in the smart grid is critical for the sustainability and long-term efficiency of the energy sharing process. Thus, prosumer management has attracted increasing attention among researchers in recent years. This paper systematically examines the literature on prosumer community based smart grid by reviewing relevant literature published from 2009 to 2018 in reputed energy and technology journals. We specifically focus on two dimensions namely prosumer community groups and prosumer relationships. Based on the evaluated literature, we present eight propositions and thoroughly describe several future research directions.


2010 ◽  
Vol 374 (40) ◽  
pp. 4112-4114 ◽  
Author(s):  
Guo-Hua Sun ◽  
Shi-Hai Dong

2014 ◽  
Vol 15 (4) ◽  
pp. 959-980 ◽  
Author(s):  
Jun Zhu ◽  
Jianxian Qiu

AbstractIn this paper, we present a new type of Hermite weighted essentially non-oscillatory (HWENO) schemes for solving the Hamilton-Jacobi equations on the finite volume framework. The cell averages of the function and its first one (in one dimension) or two (in two dimensions) derivative values are together evolved via time approaching and used in the reconstructions. And the major advantages of the new HWENO schemes are their compactness in the spacial field, purely on the finite volume framework and only one set of small stencils is used for different type of the polynomial reconstructions. Extensive numerical tests are performed to illustrate the capability of the methodologies.


1993 ◽  
Vol 04 (06) ◽  
pp. 1147-1159 ◽  
Author(s):  
HANS GERD EVERTZ ◽  
MIHAI MARCU

We discuss the loop-algorithm, a new type of cluster algorithm that reduces critical slowing down in vertex models and in quantum spin systems. We cover the example of the 6-vertex model in detail. For the F-model, we present numerical results that demonstrate the effectiveness of the loop algorithm. We show how to modify the original algorithm for some more complicated situations, especially for quantum spin systems in one and two dimensions, and we discuss parallelization.


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