Search results

This paper aims to investigate the electrochromic (EC) properties of poly(triphenylamine alkyl ether) and poly(triphenylamine aryl ether) in two different electrolyte solution to study the resistive switching behaviour of acid-doped poly(triphenylamine alkyl ether).

By Buchwald–Hartwig coupling reaction, two novel poly[N-p-phenoxy-N-[4-[2-(2-methoxyethoxy)ethoxy]ethoxy]triphenylamineandpoly[N,N-bis(4-phenoxy)]triphenylamine were synthesized from 4-phenoxyaniline and two dibromo aromatic compounds, 1,2-bis[β,β′-(p-bromophenoxy)ethoxy]ethane and bis(4-bromophenyl) ether.

Poly(triphenylamine alkyl ether) displayed excellent EC characteristics, with a coloration change from a colourless neutral state to light blue and red oxidized states, while poly(triphenylamine aryl ether) showed coloration a change from a colourless neutral state to light blue oxidized state in tetrabutylammonium perchlorate electrolyte solution. Moreover, p-toluenesulfonic acid-doped poly(triphenylamine alkyl ether) exhibited a non-volatile bistable resistive switching behaviour with a high high-conductivity/low-conductivity ratio of up to 104, long retention time exceeding 2.5 × 10³ s and the switching threshold voltage was also lower than −2V.

In this paper, the non-volatile bistable resistive switching behaviour of acid-dopedpoly(triphenylamine alkyl ether) was in accordance with the molar ratio of 1:1. The effects of different molar ratios remained to be studied.

Poly(triphenylamine ether)s may find optoelectronic applications as new EC and resistive switching materials.

The effects of alkyl and aryl ether structures in the main chain on the EC and resistive switching behaviour of triphenylamine unit have not yet been reported.

This paper aims to investigate the lubrication performance of cam/tappet contact during start up. Especially, the thermal insulation effects of coating on the lubrication performance during cold start up process and warm start up process are studied.

A numerical model for the analysis of thermal elastohydrodynamic lubrication of coated cam/tappet contact is presented. In this model, the Reynolds equation and the energy equations are discretized by the finite difference method and solved jointly.

During start up, the contact force at cam nose-to-tappet contact decreases with increasing time, while the absolute entrainment velocity has the upward trend. The minimum film thickness, maximum average temperature and friction power loss increase with increasing time, while the coefficient of friction decreases during start up. Because of the thermal insulation effect, the coating can significantly increase the degree of temperature rise. Compared with the uncoated case, the coated cam/tappet results in a lower friction power loss. Generally, the friction power loss in the cold start up process is much higher than that in the warm start up process.

By this study, the lubrication performance and the kinematics and the dynamics of the cam/tappet during start up process are investigated. Meanwhile, the thermal insulation effect of coating is also illustrated. The difference of lubrication performance between cold start up process and warm start up process is analyzed. The results and thermal elastohydrodynamic lubrication method presented in this study can be a guidance in the design of the coated cam/tappet.

This paper is dedicated to answer two questions: What is the business model of interactive television (iTV) ad at China’s Spring Festival Gala; and Why the business model of iTV ad creates different commercial values for different firms.

The two questions can be summarized as what and why problems; so, this paper adopts the method of the qualitative case study. For the first question, this paper uses the method of system activity diagram to design the business model. For the second question, this paper proposes a new analytical method – voice, incentive and convenience (VIC) model, which is used to analyze the commercial value of iTV ad. The proposal of VIC model is based on Wang et al.’s Iceberg theory.

The effect of interactive advertising is significantly better than that of traditional advertising, and interactive advertising is becoming the first choice for marketers. The business model innovation of iTV ad brings new business opportunities. In addition, the larger the area of the triangle surrounded by the three elements of VIC, the higher the commercial value of iTV ad.

Current business model studies focus on business model definitions and innovations, whereas the studies on business model evaluation and its influential factors are rare. A new analytical model named VIC is proposed. It explores the effect of VIC on the commercial value of iTV ad and provides a reference for the quantitative empirical analysis. The combination of activity system theory and VIC model contributes to the understanding of the explicit knowledge and tacit knowledge of iTV ad business model. This framework can be used to guide TV stations and stakeholders for business model innovations and optimizations.