scholarly journals A Review of Current Development of Graphene Mechanics

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 357 ◽  
Author(s):  
Qiang Cao ◽  
Xiao Geng ◽  
Huaipeng Wang ◽  
Pengjie Wang ◽  
Aaron Liu ◽  
...  

Graphene, a two-dimensional carbon in honeycomb crystal with single-atom thickness, possesses extraordinary properties and fascinating applications. Graphene mechanics is very important, as it relates to the integrity and various nanomechanical behaviors including flexing, moving, rotating, vibrating, and even twisting of graphene. The relationship between the strain and stress plays an essential role in graphene mechanics. Strain can dramatically influence the electronic and optical properties, and could be utilized to engineering those properties. Furthermore, graphene with specific kinds of defects exhibit mechanical enhancements and thus the electronic enhancements. In this short review, we focus on the current development of graphene mechanics, including tension and compression, fracture, shearing, bending, friction, and dynamics properties of graphene from both experiments and numerical simulations. We also touch graphene derivatives, including graphane, graphone, graphyne, fluorographene, and graphene oxide, which carve some fancy mechanical properties out from graphene. Our review summarizes the current achievements of graphene mechanics, and then shows the future prospects.

Author(s):  
Rumi Tano ◽  
Hiroko Miura ◽  
Katsuo Oshima ◽  
Kanako Noritake ◽  
Hideki Fukuda

Objective: The need to make sense of coherence in placement support for student dental hygienists has been shown. On this basis, this study investigated the relationship between the sense of coherence of student dental hygienists and their view of the profession and attitude to work in order to clarify how they perceive their prospects for employment. Methods: The subjects were graduation-year students at all of the dental hygienist training institutions in Japan, and anonymous, self-administered questionnaires were sent to the institutions by post in 2019. The results were analyzed by χ2 tests, as well as one-way analysis of variance and multiple comparisons using Tukey’s test, with the level of significance set at 5%. Results: Of 6270 questionnaires that were returned, 6264 were analyzed. The sense of coherence (SOC) component senses were manageability (F(26,221) = 5306.06, p < 0.01), meaningfulness (F(26,222) = 4373.48, p < 0.01), and comprehensibility (F(26,216) = 3986.12, p < 0.01), with meaningfulness scoring significantly higher than the other two (p < 0.01). Analysis with SOC scores divided into the low, medium, and high groups showed a relationship between the SOC of student dental hygienists and their view of the profession and attitude to work (p < 0.01), such that higher SOC scores were associated with a better view of the profession and a better attitude to work (F(26,225) = 282.18, p < 0.01). Conclusions: The results suggest that education that increases SOC in dental hygienist training programs may positively affect future prospects for student dental hygienists.


Author(s):  
Minju Park ◽  
Namhee Kim ◽  
Jiyoung Lee ◽  
Minsu Gu ◽  
Byeong-Su Kim

Even though many graphene derivatives that are atomically thin two-dimensional structures, such as graphene oxide (GO), have triggered enormous interest in the scientific and industrial communities owing to their easy...


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3310
Author(s):  
Shengda Liu ◽  
Jiayun Xu ◽  
Xiumei Li ◽  
Tengfei Yan ◽  
Shuangjiang Yu ◽  
...  

In the past few decades, enormous efforts have been made to synthesize covalent polymer nano/microstructured materials with specific morphologies, due to the relationship between their structures and functions. Up to now, the formation of most of these structures often requires either templates or preorganization in order to construct a specific structure before, and then the subsequent removal of previous templates to form a desired structure, on account of the lack of “self-error-correcting” properties of reversible interactions in polymers. The above processes are time-consuming and tedious. A template-free, self-assembled strategy as a “bottom-up” route to fabricate well-defined nano/microstructures remains a challenge. Herein, we introduce the recent progress in template-free, self-assembled nano/microstructures formed by covalent two-dimensional (2D) polymers, such as polymer capsules, polymer films, polymer tubes and polymer rings.


1990 ◽  
Vol 05 (16) ◽  
pp. 1251-1258 ◽  
Author(s):  
NOUREDDINE MOHAMMEDI

We find the relationship between the Jackiw-Teitelboim model of two-dimensional gravity and the SL (2, R) induced gravity. These are shown to be related to a two-dimensional gauge theory obtained by dimensionally reducing the Chern-Simons action of the 2+1 dimensional gravity. We present an explicit solution to the equations of motion of the auxiliary field of the Jackiw-Teitelboim model in the light-cone gauge. A renormalization of the cosmological constant is also given.


2016 ◽  
Vol 24 (2) ◽  
pp. 245-264
Author(s):  
Andrew P. Wilson

One of the grand scenes of the Passion narratives can be found in John’s Gospel where Pilate, presenting Jesus to the people, proclaims “Behold the man”: “Ecce Homo.” But what exactly does Pilate mean when he asks the reader to “Behold”? This paper takes as its point of departure a roughly drawn picture of Jesus in the “Ecce Homo” tradition and explores the relationship of this picture to its referent in John’s Gospel, via its capacity as kitsch devotional art. Contemporary scholarship on kitsch focuses on what kitsch does, or how it functions, rather than assessing what it is. From this perspective, when “beholding” is understood not for what it reveals but for what it does, John’s scene takes on a very different significance. It becomes a scene that breaks down traditional divisions between big and small stories, subject and object as well as text and context. A kitsch perspective opens up possibilities for locating John’s narrative in unexpected places and experiences. Rather than being a two-dimensional departure from the grandeur of John’s trial scene, kitsch “art” actually provides a lens through which the themes and dynamics of the narrative can be re-viewed with an expansiveness somewhat lacking from more traditional commentary.



2021 ◽  
Vol 23 (14) ◽  
pp. 8784-8791
Author(s):  
Qingling Meng ◽  
Ling Zhang ◽  
Jinge Wu ◽  
Shuwei Zhai ◽  
Xiamin Hao ◽  
...  

Theoretical screening of transition metal atoms anchored on monolayer C9N4 as highly stable, catalytically active and selective single-atom catalysts for nitrogen fixation.


2014 ◽  
Vol 580-583 ◽  
pp. 3208-3214 ◽  
Author(s):  
Zhen Wei Xiong ◽  
Xin Ling Liang ◽  
Xian Xing Dai ◽  
Ping Wang

when the ballast track stretch with the bridge, ballast which is near expansion joint will move confusedly. As a result, rail produced vertical deformation. The deformation will affect the running safety and comfortability of train. At present, there are two kinds of treatments which are cover board structure and baffle structure to deal ballast’s movement. Aiming at the different modes of stretching when the two kinds of structures and different arrangement condition of bridge plate are applied, the rail-sleeper-ballast discrete element model is developed by the method of two-dimensional granular flow. The relationship between rail deformation and bridge expansion is analyzed on the foundation of the model. Results show as flows: when bridge extends or shortens, rail always produced upwarp deformation. Bridge plate should arrange asymmetrically. Like this, the rail deformation decrease by 40%. And adopting the baffle structure can effectively reduce the influence of bridge expansion in ballast truck.


Author(s):  
L F Campanile ◽  
R Jähne ◽  
A Hasse

Classical beam models do not account for partial restraint of anticlastic bending and are therefore inherently inaccurate. This article proposes a modification of the exact Bernoulli–Euler equation which allows for an exact prediction of the beam's deflection without the need of two-dimensional finite element calculations. This approach offers a substantial reduction in the computational effort, especially when coupled with a fast-solving schema like the circle-arc method. Besides the description of the new method and its validation, this article offers an insight into the somewhat disregarded topic of anticlastic bending by a short review of the published theories and a selection of representative numerical results.


2022 ◽  
Author(s):  
Huixin Ma ◽  
Daijie Deng ◽  
Honghui Zhang ◽  
Feng Chen ◽  
Junchao Qian ◽  
...  

Nitrogen-coordinated single-atom manganese in multi-dimensional nitrogen-doped carbon electrocatalysts (Mn-NC) was successful constructed by combing two-dimensional nanosheets and one-dimensional nanofibers. The Mn-NC exhibited excellent oxygen reduction reaction catalytic activity with half-wave...


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