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The purpose of this study is to propose a torque vectoring control system for improving the handling stability of distributed drive electric buses under complicated driving conditions. Energy crisis and environment pollution are two key pressing issues faced by mankind. Pure electric buses are recognized as the effective method to solve the problems. Distributed drive electric buses (DDEBs) as an emerging mode of pure electric buses are attracting intense research interests around the world. Compared with the central driven electric buses, DDEB is able to control the driving and braking torque of each wheel individually and accurately to significantly enhance the handling stability. Therefore, the torque vectoring control (TVC) system is proposed to allocate the driving torque among four wheels reasonably to improve the handling stability of DDEBs.

The proposed TVC system is designed based on hierarchical control. The upper layer is direct yaw moment controller based on feedforward and feedback control. The feedforward control algorithm is designed to calculate the desired steady-state yaw moment based on the steering wheel angle and the longitudinal velocity. The feedback control is anti-windup sliding mode control algorithm, which takes the errors between actual and reference yaw rate as the control variables. The lower layer is torque allocation controller, including economical torque allocation control algorithm and optimal torque allocation control algorithm.

The steady static circular test has been carried out to demonstrate the effectiveness and control effort of the proposed TVC system. Compared with the field experiment results of tested bus with TVC system and without TVC system, the slip angle of tested bus with TVC system is much less than without TVC. And the actual yaw rate of tested bus with TVC system is able to track the reference yaw rate completely. The experiment results demonstrate that the TVC system has a remarkable performance in the real practice and improve the handling stability effectively.

In view of the large load transfer, the strong coupling characteristics of tire , the suspension and the steering system during coach corning, the vehicle reference steering characteristics is defined considering vehicle nonlinear characteristics and the feedforward term of torque vectoring control at different steering angles and speeds is designed. Meanwhile, in order to improve the robustness of controller, an anti-integral saturation sliding mode variable structure control algorithm is proposed as the feedback term of torque vectoring control.

This paper aims to conceptualize two patterns of user recognition mechanisms and two kinds of user contribution behavior in enterprise-hosted online product innovation community and explain their relationships between user recognition mechanisms and user contribution behavior of online product innovation community.

A Chinese enterprise-hosted online innovation community and an American enterprise-hosted online innovation community are selected as research objects. Four Logit models are developed and some hypotheses are supposed from the perspective of prosocial behavior theory. Objective user data with three months from two online product innovation communities are collected to test with Logit regression analysis.

Findings show that there are obvious correlations between user recognition mechanisms and user contribution behavior, and there is also an obvious difference in community user activity level between the quantity-based user recognition mechanism community and the quality-based user recognition mechanism community. More specifically, in the online product innovation community with quantity-based recognition mechanism, both variables of peer recognition and community image motivation significantly affect user proactive contribution behavior. In the online product innovation community with quality-based recognition mechanism, the variable of peer recognition significantly affects both user proactive contribution behavior and user responsive contribution behavior; the variable of community image motivation significantly affects both user proactive contribution behavior and user responsive contribution behavior.

Although it is voluntary, online user voluntary contribution behavior still need to be presented, recognized and affirmed by community. For enterprise-hosted online community managers, they should pay more attention to design the reasonable online community user recognition mechanism with the coexistence of quantity and quality.

The theoretical contribution in this study is to enrich the existing research theme about enterprise-hosted online product innovation community. First, it conceptualizes two patterns of user recognition mechanisms. Second, it regards the variable of user contribution behavior as the co-existence of proactive contribution and responsive contribution. Third, from the perspective of prosocial behavior theory, it is an important supplement to explain the mechanism of user contribution behavior in enterprise-hosted online product innovation community. Fourth, it deepens the overall understanding of the relationship between user recognition mechanism and user contribution behavior. This study provides theoretical guidance for enterprises how to design reasonable and efficient online product innovation community platform. The theoretical contribution in this study is to enrich the existing research theme about enterprise-hosted online product innovation community. First, it conceptualizes two patterns of user recognition mechanisms. Second, it regards the variable of user contribution behavior as the co-existence of proactive contribution and responsive contribution. Third, from the perspective of prosocial behavior theory, it is an important supplement to explain the mechanism of user contribution behavior in enterprise-hosted online product innovation community. Fourth, it deepens the overall understanding of the relationship between user recognition mechanism and user contribution behavior. This study provides theoretical guidance for enterprises how to design reasonable and efficient online product innovation community platform.

This paper aims to investigate the tribology, corrosion resistance and biocompatibility of high-temperature gas-nitrided Ti6Al4V alloy.

The tribological properties were studied by reciprocating wear tester. The corrosion resistance was evaluated by using potentiodynamic polarization test. The purified mouse leukaemic monocyte macrophage cells are used to investigate the biocompatibility.

The results show that the nitriding treatment leads to a significant improvement in the hardness and tribological properties of Ti6Al4V alloy. Specifically, compared to untreated Ti6Al4V, the hardness increases from 3.24 to 9.02 GPa, while the wear rate reduces by 12.5 times in sliding against a Ti6Al4V cylinder and 19.6 times in sliding against a Si3N4 ball. Furthermore, the nitriding treatment yields an improved corrosion resistance and a biocompatibility similar to that of untreated Ti6Al4V.

The nitrided Ti6Al4V alloy is an ideal material for the fabrication of load-bearing artificial implants.

This paper aims to investigate the effects of plasma nitriding and Ti-C:H coating deposition on AISI 316L and to find the best tribological performance of various specimens.

An experimental investigation is performed into the effects of plasma nitriding and Ti-C:H sputtering on the tribological properties of AISI 316L biomedical stainless steel. Five samples are prepared, namely, original AISI 316L stainless steel (code: 316L), nitrided 316L (code: N316), 316L and N316 sputtered with Ti-C:H (codes: D316 and DN316, respectively) and polished N316 sputtered with Ti-C:H (DN316s). The microstructure, mechanical properties and coating adhesion strength of the various samples are investigated and compared. The tribological properties of the samples are then evaluated by means of reciprocating wear tests performed in 8.9 Wt.% NaCl solution against three different counterbodies, namely, a 316L ball, Ti₆Al₄V ball and Si₃N₄ ball.

It is shown that plasma nitriding followed by Ti-C:H deposition (DN316s) improves the tribological properties of AISI 316L; the sample provides the best tribological performance of the various specimens and has a wear rate approximately 156 times lower than that of the original 316L substrate.

The results suggest that nitriding followed by polishing and Ti-C:H sputtering provides an effective means of improving the service life of AISI 316L biomedical implants.

Persistent change has placed considerable pressure on organizations to keep up or fade into obscurity. Firms that remain viable, or even thrive, are staffed with decision-makers who capably steer organizations toward opportunities and away from threats. Accordingly, leadership development has never been more critical. In this chapter, the authors propose that leader development is an inherently dyadic process initiated to communicate formal and informal expectations. The authors focus on the informal component, in the form of organizational politics, as an element of leadership that is critical to employee and company success. The authors advocate that superiors represent the most salient information source for leader development, especially as it relates to political dynamics embedded in work systems. The authors discuss research associated with our conceptualization of dyadic political leader development (DPLD). Specifically, the authors develop DPLD by exploring its conceptual underpinnings as they relate to sensemaking, identity, and social learning theories. Once established, the authors provide a refined discussion of the construct, illustrating its scholarly mechanisms that better explain leader development processes and outcomes. The authors then expand research in the areas of political skill, political will, political knowledge, and political phronesis by embedding our conceptualization of DPLD into a political leadership model. The authors conclude by discussing methodological issues and avenues of future research stemming from the development of DPLD.

The purpose of this study was to bring a new structural hybrid design approach to improve the mechanical and biological properties of the bone scaffolds fabricated by laser powder bed fusion, selective laser melting (SLM).

In designing the hybrid scaffolds, different unit cells were used such as dodecahedron (DCH), grid (G), octet-truss (OCT) with partially dense (PDsl) and fully dense (FDsl) surface layers. After fabrication of scaffolds on SLM machine, compression test and cell viability test were applied to observe the effect of hybrid design on mechanical and biological properties of the scaffolds.

It has been observed that designing the scaffold with partially dense or FDsl surfaces did not have a critical effect on the cell viability. On the contrary, the compression strength of scaffold increased from 56  to 100 MPa when the surface layer of the scaffold was designed as FDsl surface instead of partially dense surface. It has also been observed that the scaffold having the highest hybridity (PDsl+G+DCH+OCT) delivered the highest cell viability performance and had a compressive strength slightly higher than that of the scaffolds with single unit cell, PDsl+OCT.

This study brings a new approach to designing femur bone scaffold for fabricating with SLM. This hybrid design approach, including different unit cells in a single scaffold, covers many requirements of femur bone in terms of mechanical and biological properties.

The purpose of this paper is to propose that online group buying is different from the traditional purchase model in that an aggregation of purchases on the internet can lead sellers to adopt various bargaining strategies. When buyers and sellers do not have the opportunity to meet face to face, consumer satisfaction is an important consideration for sellers.

This study investigates the influence of sellers’ strategies for offering bargains on consumers’ satisfaction, considering buyers’ characteristics and involvement. Data are analyzed by employing the multivariate analysis of variance.

The results demonstrate that the stage decreasing range strategy results in the highest level of consumer satisfaction with online group buying. In addition, consumers’ cognitive style, computer self-efficacy and involvement have a significant moderating effect on the relationship between incentive strategy and consumer satisfaction.

The findings show that for group buying consumers, stage decreasing range strategy reveals certain advantages, such as a short waiting time for gathering group buyers. Enterprises or online sellers that propose special offers for online group buying as part of their competitive strategy should consider the stage decreasing range strategy. Moreover, enterprises and sellers can adjust their operations according to consumers’ individual characteristics and construct good relationships in online group buying.

This study has investigated the influence of incentive strategies for offering bargains in online transactions on consumer’s satisfaction. The results of this study will provide some guidelines for managers of the e-retailing firms to maximize their abilities in terms of marketing activities.

This paper aims to study the influence of NaNO₂ on the chemical composition of passivation film.

X-ray photoelectron spectroscopy and X-ray diffraction were selected to determine the composition of passivation film of steel bars in mortar. The specimens were exposed to the chloride solution, carbonation environment and the coupling effects of chloride solution and carbonation. The chemical composition and micro structures at 0 and 5 nm from the outer surface of the passivation film of steel bars were analyzed.

Results showed that the nitrite inhibitor improved the forming rate of the passivation film and increased the mass ratio of Fe₃O₄ to FeOOH on the surface of steel bars. The component of Fe₃O₄ at 5 nm of the steel passivation film was more than that at 0 nm. Sodium ferrite in the pore solution was easily hydrolyzed and then FeOOH was formed. Therefore, due to the nitrite inhibitor, a “double layer structure” of the passivation film was formed to prevent steels bars from corrosion.

This is original work and may help the researchers further understand the mechanism of rust resistance by nitrite inhibitor.

The purpose of this paper is to numerically investigate the flow characteristics and extend the data of friction factor and Reynolds number product of hydrodynamically developing laminar flow in three-dimensional rectangular microchannels with different aspect ratios.

Using a finite-volume approach, the friction factor characteristics of Newtonian fluid in three-dimensional rectangular ducts with aspect ratios from 0.1 to 1 are conducted numerically under no-slip boundary conditions. A simple model that approximately predicts the apparent friction factor and Reynolds number product f_appRe is referenced as a semi-theoretical fundamental analysis for numerical simulations.

The accurate and reliable results of f_appRe are obtained, which are compared with classic numerical data and experimental data, and the simple semi-theoretical model used and all comparisons show good agreement. Among them, the maximum relative error with the classic numerical data is less than 3.9 per cent. The data of f_appRe are significantly extended to other different aspect ratios and the novel values of f_appRe are presented in the tables. The characteristics of f_appRe are analyzed as a function of a non-dimensional axial distance and the aspect ratios. A more effective and accurate fourth-order fitting equation for the Hagenbach's factor of rectangular channels is proposed.

From the reliable data, it is shown that the values of f_appRe and the model can be references of pressure drop and friction factor for developing laminar flow in rectangular channels for researchers and engineering applications.