Mechanical and Environmental Stability of Polymer Thin-Film-Coated Graphene

Yan, Chao,Kim, Kwang-Seop,Lee, Seoung-Ki,Bae, Sang-Hoon,Hong, Byung Hee,Kim, Jae-Hyun,Lee, Hak-Joo,Ahn, Jong-Hyun American Chemical Society 2012 ACS NANO Vol.6 No.3

<P>A uniform polymer thin layer of controllable thickness was bar-coated onto a chemical vapor deposition (CVD) grown monolayer graphene surface. The effects of this coating layer on the optical, electric, and tribological properties were then investigated. The thin polymer coating layer did not reduce the optical transmittance of the graphene films. The variation in the sheet resistance of the graphene films after the coating depended on the interaction between polymer and graphene. The top coating layer can maintain the high conductivity of chemical doped graphene films under long-term ambient conditions compared with uncovered doped samples. Friction tests demonstrated that the polymer coating layer can enhance both the friction force and the coefficient of friction of the graphene films and protect the graphene against damage in the repeated sliding processes.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-3/nn203923n/production/images/medium/nn-2011-03923n_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn203923n'>ACS Electronic Supporting Info</A></P>

The Influence of Corporate Social Capital on Innovation Performance: A Case Study of Chinese Technological Small and Medium-sized Enterprises

Yan Chao,김도근 사단법인 한국융합기술연구학회 2023 아시아태평양융합연구교류논문지 Vol.9 No.3

In the case of open competition and the proliferation of patents, Chinese technology-based small and medium-sized enterprises(SMEs) still face the bottleneck of insufficient innovation resources. It is urgent to use corporate social capital to complete the transition from traditional internal accumulation to the realization of resource sharing. The connection between social capital and the performance of SMEs that rely on technology in terms of innovation, however, has not been well studied. This paper constructs a logical structure based on social capital formation in China’s economic transition course. A questionnaire survey of 523 Chinese technology-based SMEs, using regression analysis and PROCESS procedures, examines the relevance between corporate social capital and innovation efficiency and explores the impact of organizational learning on this process. According to the research, corporate social capital significantly affects the effectiveness of corporate innovation while organizational learning serves as an intermediary variable. This conclusion not only enriches and improves the research on how corporate social capital affects innovation performance but also provides important inspiration for technological SMEs in the transitional economy to strengthen innovation management.

Ag-doping behavior on (8, 0) single-walled carbon nanotube with single C-vacancy or pyridine-like N3 defect: a DFT study

Yan Chao,Zeng Qunfeng,Zhu Jianing 한국탄소학회 2019 Carbon Letters Vol.29 No.6

Single C-vacancy and pyridine-like N3 defect are usually formed on the single-walled carbon nanotube (SWCNT) and they have unique properties for potential applications. In this paper, we use density functional theory to investigate the discrepancies of such two structures from the geometric and electronic aspects. Our results indicate that the existed single vacancy in the SWCNT can lead to somewhat electron localization because of the lone pair electrons; while the N3 embedded SWCNT (N3-SWCNT) has stronger chemical reactivity and electron localization than the single vacancy SWCNT (SV-SWCNT) due to the great charge transfer between N3 group and C atom on the tube sidewall. Through the investigation of Ag-doping on the above two nano-structures, we found that the single Ag atom is much more stably adsorbed on the N3-SWCNT sidewall compared with SV-SWCNT, forming higher binding energy and higher electron transfer. Our calculation would shed light on the physicochemical property of SWCNT-based material and thus extend their potential applications in many fields.

Input energy spectra and energy characteristics of the hysteretic nonlinear structure with an inerter system

Yanchao Wang,Qingjun Chen,Zhipeng Zhao,Xiuyan Hu 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.6

The typical inerter system, the tuned viscous mass damper (TVMD), has been proven to be efficient. It is characterized by an energy-dissipation-enhancement effect, whereby the dashpot deformation of TVMD can be amplified for enhanced energy dissipation efficiency. However, existing studies related to TVMD have mainly been performed on elastic structures, so the working mechanism remains unclear for nonlinear structures. To deal with this, an energy-spectrum analysis framework is developed systematically for classic bilinear hysteretic structures with TVMD. Considering the soil effect, typical bedrock records are propagated through the soil deposit, for which the designed input energy spectra are proposed by considering the TVMD parameters and structural nonlinear properties. Furthermore, the energy-dissipation-enhancement effect of TVMD is quantitatively evaluated for bilinear hysteretic structures. The results show that the established designed input energy spectra can be employed to evaluate the total energy-dissipation burden for a nonlinear TVMD structure. Particularly, the stiffness of TVMD is the dominant factor in adjusting the total input energy. Compared with the case of elastic structures, the energy-dissipation-enhancement effect of TVMD for nonlinear structures is weakened so that the expected energy-dissipation effect of TVMD is replaced by the accumulated energy dissipation of the primary structure.

Responses of Soil Physico-Chemical Properties, Ryegrass Growth And Uptake of Nutrients and Heavy Metals to Dairy Manure Amendment in a Mudflat Soil

Yanchao Bai,Gulin Huang,Wengang Zuo,Xiaowen Zhu,Xiaocheng Ying,Ke Feng,Yuhua Shan 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Bond slip modelling and its effect on numerical analysis of blast-induced responses of RC columns

Yanchao Shi,Hong Hao,Zhong-Xian Li 국제구조공학회 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.32 No.2

Reinforced concrete (RC) structures consist of two different materials: concrete and steel bar. The stress transfer behaviour between the two materials through bond plays an important role in the loadcarrying capacity of RC structures, especially when they subject to lateral load such as blast and seismic load. Therefore, bond and slip between concrete and reinforcement bar will affect the response of RC structures under such loads. However, in most numerical analyses of blast-induced structural responses, the perfect bond between concrete and steel bar is often assumed. The main reason is that it is very difficult to model bond slip in the commercial finite element software, especially in hydrodynamic codes. In the present study, a one-dimensional slide line contact model in LS-DYNA for modeling sliding of rebar along a string of concrete nodes is creatively used to model the bond slip between concrete and steel bars in RC structures. In order to model the bond slip accurately, a new approach to define the parameters of the one-dimensional slide line model from common pullout test data is proposed. Reliability and accuracy of the proposed approach and the one-dimensional slide line in modelling the bond slip between concrete and steel bar are demonstrated through comparison of numerical results and experimental data. A case study is then carried out to investigate the bond slip effect on numerical analysis of blast-induced responses of a RC column. Parametric studies are also conducted to investigate the effect of bond shear modulus, maximum elastic slip strain, and damage curve exponential coefficient on blast-induced response of RC columns. Finally, recommendations are given for modelling the bond slip in numerical analysis of blast-induced responses of RC columns.

Bond slip modelling and its effect on numerical analysis of blast-induced responses of RC columns

Shi, Yanchao,Li, Zhong-Xian,Hao, Hong Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.32 No.2

Reinforced concrete (RC) structures consist of two different materials: concrete and steel bar. The stress transfer behaviour between the two materials through bond plays an important role in the load-carrying capacity of RC structures, especially when they subject to lateral load such as blast and seismic load. Therefore, bond and slip between concrete and reinforcement bar will affect the response of RC structures under such loads. However, in most numerical analyses of blast-induced structural responses, the perfect bond between concrete and steel bar is often assumed. The main reason is that it is very difficult to model bond slip in the commercial finite element software, especially in hydrodynamic codes. In the present study, a one-dimensional slide line contact model in LS-DYNA for modeling sliding of rebar along a string of concrete nodes is creatively used to model the bond slip between concrete and steel bars in RC structures. In order to model the bond slip accurately, a new approach to define the parameters of the one-dimensional slide line model from common pullout test data is proposed. Reliability and accuracy of the proposed approach and the one-dimensional slide line in modelling the bond slip between concrete and steel bar are demonstrated through comparison of numerical results and experimental data. A case study is then carried out to investigate the bond slip effect on numerical analysis of blast-induced responses of a RC column. Parametric studies are also conducted to investigate the effect of bond shear modulus, maximum elastic slip strain, and damage curve exponential coefficient on blast-induced response of RC columns. Finally, recommendations are given for modelling the bond slip in numerical analysis of blast-induced responses of RC columns.

Lactate promotes vascular smooth muscle cell switch to a synthetic phenotype by inhibiting miR-23b expression

Hu Yanchao,Zhang Chunyan,Fan Yajie,Zhang Yan,Wang Yiwen,Wang Congxia 대한약리학회 2022 The Korean Journal of Physiology & Pharmacology Vol.26 No.6

Recent research indicates that lactate promotes the switching of vascular smooth muscle cells (VSMCs) to a synthetic phenotype, which has been implicated in various vascular diseases. This study aimed to investigate the effects of lactate on the VSMC phenotype switch and the underlying mechanism. The CCK-8 method was used to assess cell viability. The microRNAs and mRNAs levels were evaluated using quantitative PCR. Targets of microRNA were predicted using online tools and confirmed using a luciferase reporter assay. We found that lactate promoted the switch of VSMCs to a synthetic phenotype, as evidenced by an increase in VSMC proliferation, mitochondrial activity, migration, and synthesis but a decrease in VSMC apoptosis. Lactate inhibited miR-23b expression in VSMCs, and miR-23b inhibited VSMC's switch to the synthetic phenotype. Lactate modulated the VSMC phenotype through downregulation of miR-23b expression, suggesting that overexpression of miR-23b using a miR-23b mimic attenuated the effects of lactate on VSMC phenotype modulation. Moreover, we discovered that SMAD family member 3 (SMAD3) was the target of miR-23b in regulating VSMC phenotype. Further findings suggested that lactate promotes VSMC switch to synthetic phenotype by targeting SMAD3 and downregulating miR-23b. These findings suggest that correcting the dysregulation of miR-23b/ SMAD3 or lactate metabolism is a potential treatment for vascular diseases.

중국 상업은행 사외이사 독립성에 관한 연구

이안초(LI YANCHAO) 전북대학교 법학연구소 2012 法學硏究 Vol.36 No.-

중국 상업은행의 사외이사는 금융리스크를 감독하고 소수주주와 예금자의 이익을 보호하고 지배주주와 경영진을 견제하는 역할을 한다. 이러한 역할을 발휘할 수 있도록 사외이사는 이사회, 경영진 또는 기타 지배인의 영향에 벗어나고 경영활동 또는 회사의 중대한 사항에 대하여 독립적인 의견과 판단을 할 수 있어야 한다. 따라서 사외이사의 독립성을 강화시키기 위해 필자는 개선방안을 연구하고자 한다. 사외이사 후보자의 추천권은 지명위원회에 맡기고 주주의 지명권을 제한하거나 공동지배 모드를 채택하여 주주, 예금자와 가타 이해관계자가 각자로 사외이사 후보자를 추천하도록 하는 것이 타당하다고 본다. 그리고 선임에 대해서는 집중투표제도보다는 대주주의 의결권을 제한하고 소수주주, 예금자 및 기타 이해관계자가 추천한 후보자도 선임될 수 있도록 하기 위한 주주의결권제한제도를 가급적으로 실행하여야 한다고 생각한다. 상업은행 사외이사의 직무이행 독립성을 확보하기 위해서 그들에게 권한을 충분히 부여하고 권한의 이행에 보장을 제공하여야 한다. 사외이사 권한 행사에 독립성을 강화하는 반면에 사외이사 역할의 책임감과 근면성이 천차만별이므로 그들에 대해 의무와 책임도 부과하여야 한다. Unlike common corporations, in the case of commercial banks, there exist some special privileges in term of corporation governance and internal control. Compared to the boards of inside directors and Corporate Auditors, outside directors have special privilege in performing the monitoring function. Issues may occur depending on how to merge this system into the banking sectors. China commercial banks’outside directors are expected to play the role of monitoring the financial risk, protecting the interests of minority shareholders and keeping the corporate management in check. In order to carry out its role effectively, outsider directors should act independent from the influence of corporate management and inside directors. Besides that, they also should make independent and impartial decision based on their own judgement when dealing with company crucial issues. Outside director system have been introduced in China for over 10 years, although several approaches has been taken to improve the efficiency of this system, most of the outside directors in listed companies and commercial banks are still unable to be independent from the company’ management. They act more in line with the interests of inside directors. Therefore the purpose of this paper is to investigate the approaches to enhance the independence and professionalism of outside directors. In my personal opinion, restrict a shareholders nomination right and instead grant it to nominating committee or adopt a joint management system which allows a more transparent and fairer nomination by each shareholder, depositor and other interested parties may be one of the appropriate approaches to enhance the efficiency of this system. The present voting system should be replaced by limits of shareholders voting right system in order to restrict the voting right of majority shareholder and thus the candidates nominated by minority shareholders, depositors and other interested parties could have the equal opportunity. The outside directors should be granted sufficient power to ensure they can perform their duty independently. In my opinion, senior outside director system and outside director board system shall be implemented as a means of ensuring the right of action of outside directors. These moves may strengthens the independence of outside directors. On the other hand, as the responsibility and work ethnic are vary among outside directors, their duties and responsibilities should be imposed. A perfect remuneration and incentives systems are required to encourage the enhancement of aggressiveness of outside directors.

중국 광서성 생활체육참여자의 참여동기 및 운동정서와 운동지속의 관계

장염초(ZHANG YANCHAO) 한국체육과학회 2018 한국체육과학회지 Vol.27 No.3

The study was carried out to investigate the relationship between participative motivation and exercise emotion to exercise adherence of sports for all participants in Guangxi province, China. For this purpose, 859 sports for all participants students in 4cities in Guangxi Province were analyzed by frequency, validity and reliability analysis, correlation, and multiple regression analysis using SAS 9.0. As a result, First, as the result of relationship between participative motivation and exercise adherence. The sub-factors of participative motivation; enjoyment, skill development and accomplishment, health and fitness, social interaction, showed significant difference in tendency of exercise adherence. Moreover, the sub-factors of participative motivation; enjoyment, skill development and accomplishment, health and fitness, social interaction, amotivation had significant relationship with possibility of exercise adherence.. Lastly, enjoyment, skill development and accomplishment, health and fitness, amotivation factors were related to reinforcement factor of exercise adherence. Second, the analysis on exercise emotion and exercise adherence, the study found that the sub-factors of exercise emotion; enjoyment, purification, accomplishment, had significant relationship with tendency of exercise adherence. Moreover, possibility of exercise adherence had significant relationship in enjoyment, pride, accomplishment, purification. Lastly, the sub-factors of exercise emotion; enjoyment, pride, purification, accomplishment factors were positively related with reinforcement of exercise adherence.