Search results

The purpose of this paper is to conduct the synthesization of LiFePO₄-C (LFP-C) with fine particle size and enhanced electrochemical performance as the positive electrode material for Li-ion capacitors (LICs) with neutral aqueous electrolyte.

LFP-C was prepared by using polyethylene glycol (PEG) as a grain growth inhibitor, and the effects of the calcination temperature and PEG content on the structure and morphology of LFP-C were investigated. LICs using environment-friendly, safe and low-cost LiNO₃ aqueous electrolyte were assembled with LFP-C as the positive electrode and active carbon as the negative electrode. The electrochemical performances of LFP-C and LICs were studied.

The results show that the particle size of LFP-C decreases significantly through the introduction of PEG. Cyclic voltammetry results show that the LFP-C prepared at 550°C with 1.0 g PEG exhibits the highest C_pe of 725 F/g at the scanning rate of 5 mA/s. Compared to LFP prepared without PEG, the electrochemical performance of optimized LFP-C dramatically increases due to the decrease of the particle size. Moreover, the LIC assembled with the optimized LFP-C exhibits excellent electrochemical performances. The LIC maintains about 91.3 per cent of its initial C_ps after 200 cycles which shows a good cycling performance.

The LFP-C is the suitable positive electrode material for LICs with neutral aqueous electrolyte. LICs can be used in the field of automobiles and can solve the problems of energy shortage and environmental pollution.

Both the LFP-C with fine particle size and its optimal LIC using environment-friendly, safe and low-cost LiNO₃ aqueous electrolyte own good electrochemical performances.

The prerequisite for most traditional visual simultaneous localization and mapping (V-SLAM) algorithms is that most objects in the environment should be static or in low-speed locomotion. These algorithms rely on geometric information of the environment and restrict the application scenarios with dynamic objects. Semantic segmentation can be used to extract deep features from images to identify dynamic objects in the real world. Therefore, V-SLAM fused with semantic information can reduce the influence from dynamic objects and achieve higher accuracy. This paper aims to present a new semantic stereo V-SLAM method toward outdoor dynamic environments for more accurate pose estimation.

First, the Deeplabv3+ semantic segmentation model is adopted to recognize semantic information about dynamic objects in the outdoor scenes. Second, an approach that combines prior knowledge to determine the dynamic hierarchy of moveable objects is proposed, which depends on the pixel movement between frames. Finally, a semantic stereo V-SLAM based on ORB-SLAM2 to calculate accurate trajectory in dynamic environments is presented, which selects corresponding feature points on static regions and eliminates useless feature points on dynamic regions.

The proposed method is successfully verified on the public data set KITTI and ZED2 self-collected data set in the real world. The proposed V-SLAM system can extract the semantic information and track feature points steadily in dynamic environments. Absolute pose error and relative pose error are used to evaluate the feasibility of the proposed method. Experimental results show significant improvements in root mean square error and standard deviation error on both the KITTI data set and an unmanned aerial vehicle. That indicates this method can be effectively applied to outdoor environments.

The main contribution of this study is that a new semantic stereo V-SLAM method is proposed with greater robustness and stability, which reduces the impact of moving objects in dynamic scenes.

An anomaly of entrepreneurship literature was that, despite serious efforts required to manage a business, few studies had investigated entrepreneurs' health conditions at the end of their careers. This study investigated whether one's entrepreneurship in a lifetime enhanced their health after a career plateau.

The authors tested the main effect and mediating effects of entrepreneurs' life habits and self-esteem, respectively, using two longitudinal representative examples with 8,984 and 12,686 participants.

Results indicated that entrepreneurship significantly improved individuals' general lifetime health condition. Moreover, life habits (e.g. vigorous activities or sports, light activities, drinking habits and diet habits) and self-esteem significantly mediated the relationship between entrepreneurship and lifetime health. Entrepreneurs tended to have better health due to healthier life habits and higher self-esteem than salaried employees. In this paper, the authors also discussed theoretical and practical implications.

The authors proposed and found that, to counter the harsh requirements of entrepreneurial actions, entrepreneurs need to seek personal physical and psychological resources, and these resources can benefit their health even after decades.

This paper aims to investigate the following questions: What are the types of discussion prompts in a fully online graduate course? What are the key characteristics of students’ discussion initial posts and replies in a fully online graduate course? In what ways, if any, do discussion prompts influence the types of initial posts and replies in discussion threads?

This study adopted a qualitative approach to explore the dynamics of students’ knowledge construction through using asynchronous discussion boards. A total of 20 discussion prompts and 115 discussion threads from nine archival discussion boards in a fully online library science course were collected and analyzed.

The findings identified open-ended, explanatory and reflective prompts in discussion boards. Students engaged in simply stating, paraphrasing, elaborating, extending, reflecting, socializing and sharing emotions in discussion posts. These findings highlighted the interconnectedness of reflection and socio-emotional interactions in a community of inquiry and pointed out their important roles to support richer and deeper online discussions. The study further observed linkages between the types of discussion prompts and the types of discussion posts.

This study addressed an urgent need to understand the use of online discussion boards in an emergency remote teaching condition in a pandemic. The findings of this study offered educators insights into evidence-based design recommendations for prompts to support students’ knowledge construction and deep learning through using discussion boards.

The purpose of this paper is to explore the factors influencing customers’ willingness to participate in virtual brand community’s value co-creation and help companies better operating the virtual brand community.

Based on social cognitive theory and the features of the virtual brand community, this paper constructed a model of factors influencing customers’ willingness to participate in virtual brand community’s value co-creation. Then this paper quantitatively analyzed the mediating effect and the moderating effect.

The empirical analysis came to the following conclusions: first, in virtual brand communities, customers’ willingness to participate in value co-creation would be influenced by subject factors, environment factors, brand factors and perceived value factor. Second, customer involvement is an important moderator. The more involved the customer is, the more he/she will rely on the virtual brand community. Particularly, customer involvement has a positive moderating effect on the influence of subject factors, while it has a negative moderating effect on the influence of community experience and community trust. Third, perceived value plays a significant mediating role between subject factors and customers’ willingness to participate in value co-creation.

The results of this study can help companies better understand the influence of external factors like environment and brand so that they can better operate the virtual brand community and encourage customers to contribute to the development of the community and the brand.

Most of the existing studies focused on the formation of virtual brand communities and customers’ participation behaviors, but there is limited research focusing on what contributes to customers’ participation in value co-creation of virtual brand communities. This study, therefore, attempts to bridge the research gap.

The purpose of this study is to investigate the flexible dynamic characteristics about hydro-viscous drive providing meaningful insights into the credible speed-regulating behavior during the soft-start.

A comprehensive dynamic transmission model is proposed to investigate the effects of key parameters on the dynamic characteristics. To achieve a trade-off between the transmission efficiency and time proportion of hydrodynamic and mixed lubrication, a multi-objective optimization of friction pair system by genetic algorithm is presented to obtain the optimal combination of design parameters.

Decreasing the engagement pressure or the ratio of inner and outer radius, increasing the lubricating oil viscosity or the outer radius will result in the increase of time proportion of hydrodynamic and mixed lubrication, as well as the transmission efficiency and its maximum value. After optimization, main dynamic parameters including the oil film thickness, angular velocity of the driven disk, viscous torque and total torque show remarkable flexible transmission characteristics.

Both the dynamic transmission model and multi-objective optimization model are established to analyze the effects of main design parameters on the dynamic characteristics of hydro-viscous flexible drive.

This paper aims to examine the impact of the COVID-19 infodemic on the public’s online information behaviour, offering insights critical for shaping effective informational responses in future public health emergencies.

This paper uses a structured online survey with 27 targeted questions using a five-point Likert scale to measure eight variables. Data analysis is conducted through structural equation modelling on 307 valid responses to rigorously test the research hypotheses.

This paper indicates that information quality significantly impacts the public’s capacity to select, share and use online information. Additionally, the comprehensibility of information plays a crucial role in shaping the public’s behaviours in terms of online information exchange and usage. The credibility of information sources emerges as a key determinant influencing the public’s online information selection, exchange and utilization behaviour. Moreover, social influence exerts a substantial effect on the public’s online information selection, acquisition, exchange and utilization behaviour. These findings highlight the presence of universality and sociality, mediation and guidance, as well as the purposefulness and selectivity performed by the public’s online information behaviour during an infodemic.

This paper introduces a novel research model for assessing the influence and identifies the patterns of the public’s online information behaviour during the COVID-19 infodemic. The findings have significant implications for developing strategies to tackle information dissemination challenges in future major public health emergencies.

Climate risk greatly increases the risk exposure of global investments. Both the climate risks of home countries and host countries may affect international investment behaviors. The purpose of this paper is to explore the impact of climate risk and climate risk distance on foreign direct investment (FDI) inflows and outflows. Targeted proposals are provided to promote international economic and trade cooperation and the authors provide suggestions for the FDI strategies of multinational enterprises.

The authors define “climate risk distance” as the difference in climate risks between two countries. This paper uses both a theoretical model and a generalized least squares test to investigate the impact of climate risk distance on FDI from the perspectives of FDI inflows and outflows. In addition, the authors subdivide the samples according to the sign of climate risk distance and rank the FDI share from home country to host country into four groups according to the host country’s climate risk index. Finally, the authors undertake empirical tests with outward foreign direct investment (OFDI) data to support the empirical results.

Investors from countries with low climate risks have the upper hand due to their competitive advantages, like their skills, trademarks and patent rights, which they can transfer abroad to offset the disadvantage of being non-native. This is generally defined as ownership advantage. The impact of climate risk distance on FDI depends on the sign of climate risk distance. Specifically, host countries with higher climate risks compared with the climate risk levels of home countries may experience insignificant reductions in FDI inflows. For investors from home countries with higher climate risks, they are less likely to invest in host countries with lower climate risks. The results for samples from emerging market economies are shown to be more significant.

This study advances the O (ownership advantage) part of the ownership, location and internationalization (OLI) paradigm by incorporating the climate risk distance between the home country and the host country into the influencing factors of FDI. Both the O part and the L (location advantage, the advantage that host countries offers to make internationalization worthwhile to undertake FDI) part of the OLI paradigm concerning climate risks are validated with FDI and OFDI data.

The aim of this paper is to study the tribological performance and self-repairing performance of surface-modified nanoscale serpentine powders as lubricant additives in the mineral base oil (5-CST).

Fourier transform infrared spectroscopy spectra and thermo-gravimetric analysis of both modified and unmodified serpentine were performed to analyse their grafting ratio and suspension after modified using a long-chain naphthene aliphatic acid. The tribological properties of surface-modified serpentine as lubricant additives in 5-CST were evaluated and the worn surfaces were investigated by X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES).

The results show that the serpentine particles have high grafting ratio, improving the dispersity in 5-CST. When the serpentine concentration of 1.00 weight per cent is used as additives in 5-CST, friction coefficient reduces by 14.80 per cent under 294 N and wear scar diameter (WSD) decreases by 11.82 per cent. The results of X-ray absorption near edge structure and XANES show that the adsorption and tribochemical reactions occur to form self-repairing lubrication films.

The paper illustrates a tribofilm form on the rubbed surface, which is responsible for the decrease in friction and wear, mainly containing iron oxides, silicon oxides, magnesium oxides and organic compounds. The results are useful for further applications in advanced environmental friendly lubricating oils and additives.

Based on imprinting theory and episodic future thinking, this paper aims to study how CEOs’ attributes and experiences inform innovation in tourism and hospitality businesses. It also explores ways to quantify innovation in this sector.

The authors quantitatively analysed innovation in tourism and hospitality using extensive data from companies’ annual reports. They further adopted multivariate regression to test how CEOs’ experience affects enterprise innovation.

Results demonstrate that CEOs’ academic education and rich work experience can promote corporate innovation. The authors also identified a mediating role of the tone of narrative disclosure in annual reports between CEOs’ academic education and corporate innovation. The imprinting effects of career experience and educational experience appear both independent and interactive.

CEOs are more inclined to engage in corporate innovation when influenced by the combined imprinting effects of strategic management training and work experience. Additionally, leaders should consider how communication styles indirectly influence innovation activities.

This paper introduces an integrated perspective that blends imprinting theory and episodic future thinking to bridge knowledge gaps regarding the interaction of CEOs’ past experiences. This work enhances understanding of how CEOs’ imprinted experiences, together with their capacity for envisioning future scenarios, can drive corporate innovation.