Search

Your search keyword '"Chen, Zhitao"' showing total 761 results
Start Over Author "Chen, Zhitao"
761 results on '"Chen, Zhitao"'

4. Active nematic defects in compressible and incompressible flows

Author

Pokawanvit, Supavit, Chen, Zhitao, You, Zhihong, Angheluta, Luiza, Marchetti, M. Cristina, and Bowick, Mark J.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We study the dynamics of active nematic films on a substrate driven by active flows with or without the incompressible constraint.Through simulations and theoretical analysis, we show that arch patterns are stable in the compressible case, whilst they become unstable under the incompressibility constraint. For compressible flows at high enough activity, stable arches organize themselves into a smectic-like pattern, which induce an associated global polar ordering of $+1/2$ nematic defects. By contrast, divergence-free flows give rise to a local nematic order of the $+1/2$ defects, consisting of anti-aligned pairs of neighboring defects, as established in previous studies., Comment: 10 pages, 4 figures

Published
2022
Full Text
View/download PDF

8. Odd moduli of disordered odd elastic lattices

Author

Chen, Zhitao

Subjects
Condensed Matter - Soft Condensed Matter, Condensed Matter - Disordered Systems and Neural Networks
Abstract

We study the effects of bond disorder on triangular and honeycomb lattices where each spring has a probability p to be odd elastic. Using an effective medium theory and numerical simulations, we uncover the behavior of odd moduli in the presence of disorder, which we interpret as a crossover between the affine response of the passive elastic backbone, and a rigidity percolation transition in the odd elastic components. Though oddness is generally robust against disorder even at low p, we find that fine-tuned features of an odd elastic honeycomb lattice are not robust against disorder.

Published
2022

14. Spontaneous tilt of single-clamped thermal elastic sheets

Author

Chen, Zhitao, Wan, Duanduan, and Bowick, Mark J.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

Very thin elastic sheets, even at zero temperature, exhibit nonlinear elastic response by virtue of their dominant bending modes. Their behavior is even richer at finite temperature. Here we use molecular dynamics (MD) to study the vibrations of a thermally fluctuating two-dimensional elastic sheet with one end clamped at its zero-temperature length. We uncover a tilt phase in which the sheet fluctuates about a mean plane inclined with respect to the horizontal, thus breaking reflection symmetry. We determine the phase behavior as a function of the aspect ratio of the sheet and the temperature. We show that tilt may be viewed as a type of transverse buckling instability induced by clamping coupled to thermal fluctuations and develop an analytic model that predicts the tilted and untilted regions of the phase diagram. Qualitative agreement is found with the MD simulations. Unusual response driven by control of purely geometric quantities like the aspect ratio, as opposed to external fields, offers a very rich playground for two-dimensional mechanical metamaterials., Comment: Updated Supplementary Material

Published
2021
Full Text
View/download PDF

17. The role of fluid flow in the dynamics of active nematic defects

Author

Angheluta, Luiza, Chen, Zhitao, Marchetti, M. Cristina, and Bowick, Mark J.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We adapt the Halperin-Mazenko formalism to analyze two-dimensional active nematics coupled to a generic fluid flow. The governing hydrodynamic equations lead to evolution laws for nematic topological defects and their corresponding density fields. We find that $\pm 1/2$ defects are propelled by the local fluid flow and by the nematic orientation coupled with the flow shear rate. In the overdamped and compressible limit, we recover the previously obtained active self-propulsion of the +1/2 defects. Non-local hydrodynamic effects are primarily significant for incompressible flows, for which it is not possible to eliminate the fluid velocity in favor of the local defect polarization alone. For the case of two defects with opposite charge, the non-local hydrodynamic interaction is mediated by non-reciprocal pressure-gradient forces. Finally, we derive continuum equations for a defect gas coupled to an arbitrary (compressible or incompressible) fluid flow.

Published
2020
Full Text
View/download PDF

27. A randomized-controlled trial of ischemia-free liver transplantation for end-stage liver disease

Author

Guo, Zhiyong, Zhao, Qiang, Jia, Zehua, Huang, Changjun, Wang, Dongping, Ju, Weiqiang, Zhang, Jian, Yang, Lu, Huang, Shanzhou, Chen, Maogen, Zhu, Xiaofeng, Hu, Anbin, Ma, Yi, Wu, Linwei, Chen, Yinghua, Han, Ming, Tang, Yunhua, Wang, Guodong, Wang, Linhe, Li, Lifen, Xiong, Wei, Zhang, Zhiheng, Shen, Yuekun, Tang, Zhaoxia, Zhu, Caihui, Chen, Xiaoxiang, Hu, Xiaoguang, Guo, Yiwen, Chen, Honghui, Ma, Yihao, Zhang, Tao, Huang, Shunwei, Zeng, Ping, Lai, Simei, Wang, Tielong, Chen, Zhitao, Gong, Jinlong, Yu, Jia, Sun, Canhui, Li, Chang, Tan, Haiyi, Liu, Yao, Dong, Yuqi, Sun, Chengjun, Liao, Bing, Ren, Jun, Zhou, Zhenhai, Andrea, Schlegel, Björn, Nashan, Cai, Changjie, Gong, Fengqiu, Rong, Jian, Huang, Wenqi, Guan, Xiangdong, Clavien, Pierre-Alain, Stefan, Tullius G., Huang, Jiefu, and He, Xiaoshun

Published
2023
Full Text
View/download PDF

31. Is organizing self-esteem effective? Research on social characteristics of work and task performance

Author

Peng Huiyun and Chen Zhitao

Subjects
Social Sciences
Abstract

From the previous literature, it is found that there are still many shortcomings in the research on the two variables that affect task performance, employees’ social support and others’ feedback. In this study, employees’ social support, feedback from others, organization-based self-esteem, and task performance were studied. By studying the relationship between job social characteristics and task performance, the mediating role of organization-based self-esteem and the moderating role of job social characteristics are further discussed. In the future, this study will take the influence of employees’ social support and others’ feedback on task performance as the starting point, study the influence mechanism of social support and others’ feedback, enrich the cross-examination research in this aspect, analyse and discuss the research results, and explain the significance of the research, the shortcomings of viewpoints and future prospects.

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results