Xiaoqing Ni, Liang Zhang, Wenheng Wu, Dexiang Zhu, Decheng Kong, Chaofang Dong and Guoliang Zhu
Laser melting deposition (LMD) is an advanced additive manufacturing (AM) technology without powder waste, and nickel-based alloys with different Nb contents were created one-time…
Abstract
Purpose
Laser melting deposition (LMD) is an advanced additive manufacturing (AM) technology without powder waste, and nickel-based alloys with different Nb contents were created one-time by adjusting the ratio of mixed powders via a dual-feed system. Here, the authors provide a systematic report on the effects of the Nb content on the microstructure, Laves phase segregation and mechanical properties of as-received LMD nickel-based alloys. The effects of the Nb content on the microstructure, precipitation evolution and mechanical properties of the subsequent heat-treated LMD samples are also discussed in this paper.
Design/methodology/approach
Thus, the present research aims to obtain a better understanding of the effect of Nb content on the microstructural and mechanical properties of the as-received LMD Inconel 718 alloys through high-throughput sample fabrication. The microstructures were characterized by scanning electron microscopy and energy-dispersive spectroscopy, electron back-scattered diffraction and transmission electron microscopy methods. The mechanical properties were obtained from compressive tests and nano-indentation tests. Electrochemical tests, including electrochemical impedance spectroscopy and potentiodynamic polarizations, were carried out to evaluate the durability of the Inconel 718 alloys. Results can provide a factual basis for future applications of the functionally graded by AM technology.
Findings
The grain size of the as-received LMD Inconel 718 alloys decreased with the Nb content. The Laves phase distribution at the macro level was relatively uniform and the Laves phase exhibited a 1.5-fold nano-hardness compared with the matrix. The strength improvement for the as-received LMD Inconel 718 alloys with Nb content was attributed to grain refinement and enhancement of the Laves phase in terms of both hardness and content. Meanwhile, the corrosion resistance increased with the increase of the Nb content, especially for the pitting potential, which was attributed to the optimization of carbide precipitates due to the strong affinity between niobium and carbon.
Originality/value
The results provide a factual basis for the Nb content effect in LMD nickel-based alloys, and this method can greatly promote the development of new materials. The authors believe that this study makes a significant contribution to the literature and is suitable for publication.
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Xiaoxiao Zhang, Guoliang Shi and Qiupan Jin
The purpose is to explore the essential reasons for the differences between book awakening phenomena, to develop the critical factors in awakening the slumbering collections and…
Abstract
Purpose
The purpose is to explore the essential reasons for the differences between book awakening phenomena, to develop the critical factors in awakening the slumbering collections and to provide a reliable basis for maximizing book value and optimizing collection allocation.
Design/methodology/approach
The research employs the integrated learning algorithm XGBoost to measure driving factors. In the process of book circulation, the characteristics of collections and readers are worthy of attention. Therefore, this study also carries out feature selection and model construction from the two dimensions of books and readers.
Findings
The results show that reader features have a stronger impetus for the collection awakening phenomenon than collection features. Among reader features, education level, gender and major subject are the main factors, which are followed closely by the activity level; among collection features, publication date and price are the main driving factors. The indicators of book popularity are not significant, whose effect on the phenomenon of collection awakening is almost negligible.
Originality/value
This study aims to augment the theory of zero circulation from the theoretical level and, for the first time, seeks to define the phenomenon of collection awakening. This study attempts to present novel ideas for research in the field of libraries and to provide references for optimizing collection and maximizing the value of books.
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Yeqing Tao, Dongyan Ding, Ting Li, Jason Guo and Guoliang Fan
This paper aims to study the influence of reflow atmosphere and placement accuracy on the solderability of 01005 capacitor/SAC305 solder joints.
Abstract
Purpose
This paper aims to study the influence of reflow atmosphere and placement accuracy on the solderability of 01005 capacitor/SAC305 solder joints.
Design/methodology/approach
The 01005 capacitors were mounted on OSP-coated pads, and the samples were fabricated in four different atmospheres, i.e. 200 ppm O2/N2, 1,000 ppm O2/N2, 3,000 ppm O2/N2 and air. After the reflow process, visual inspection and X-ray detection were carried out to examine the solder joint shapes and possible defects. Some of the samples fabricated in different conditions were cross-sectioned and the solder joint microstructures were analyzed. On the other hand, besides placing the components on their normal pad positions, a 50 per cent offset of the x-axis (long axis) or y-axis (short axis) was introduced into the chip mounter programs to evaluate the 01005 capacitor’s assembly sensitivity to placement accuracy. The process-induced defects were investigated.
Findings
Experimental results indicated that an N2-based protective atmosphere was necessary for 01005 type assembly, as it could obviously improve the 01005 solder joint quality, compared with the air condition. The protective atmosphere had little effect on the appearance, quality and microstructure of solder joints when the oxygen concentration was below 3,000 ppm. But a very low oxygen concentration could increase the risk of tombstoning defects for the assembly process. The N2-based protective atmosphere containing 1,000-2000 ppm O2 was acceptable and appropriate for the assembly of tiny components.
Originality/value
The results of this work provide a set of reflow process parameters and recommendations for 01005 size component assembly in manufacturing.
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Erliang Yao, Hexin Zhang, Haitao Song and Guoliang Zhang
To realize stable and precise localization in the dynamic environments, the authors propose a fast and robust visual odometry (VO) approach with a low-cost Inertial Measurement…
Abstract
Purpose
To realize stable and precise localization in the dynamic environments, the authors propose a fast and robust visual odometry (VO) approach with a low-cost Inertial Measurement Unit (IMU) in this study.
Design/methodology/approach
The proposed VO incorporates the direct method with the indirect method to track the features and to optimize the camera pose. It initializes the positions of tracked pixels with the IMU information. Besides, the tracked pixels are refined by minimizing the photometric errors. Due to the small convergence radius of the indirect method, the dynamic pixels are rejected. Subsequently, the camera pose is optimized by minimizing the reprojection errors. The frames with little dynamic information are selected to create keyframes. Finally, the local bundle adjustment is performed to refine the poses of the keyframes and the positions of 3-D points.
Findings
The proposed VO approach is evaluated experimentally in dynamic environments with various motion types, suggesting that the proposed approach achieves more accurate and stable location than the conventional approach. Moreover, the proposed VO approach works well in the environments with the motion blur.
Originality/value
The proposed approach fuses the indirect method and the direct method with the IMU information, which improves the localization in dynamic environments significantly.
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Guoliang Frank Jiang and Michael A. Sartor
This study examines the contingent impact of corporate anti-corruption policies on multinational enterprises’ foreign investment strategy. The authors propose that the differences…
Abstract
This study examines the contingent impact of corporate anti-corruption policies on multinational enterprises’ foreign investment strategy. The authors propose that the differences in foreign investment motives will moderate the assumed deterrent effect of anti-corruption policies. Our analysis of overseas production investments by Japanese firms (2011–2017) supports some of the hypotheses. The authors find that the deterrent effect of anti-corruption policies may be diminished when a new subsidiary has an efficiency-seeking purpose. Conversely, the deterrent effect is more prominent when a new subsidiary has a competence-creating purpose. These results not only contribute to the research on control of corruption in international business, but also have implications for research on corporate self-regulation more generally.
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Mengyuan Cheng, Heap-Yih Chong, Guoliang Liu and Qian Li
Perceived justice is crucial to achieving public–private partnership (PPP) projects’ goals, but little is known about the transmission mechanism of perceived justice that affects…
Abstract
Purpose
Perceived justice is crucial to achieving public–private partnership (PPP) projects’ goals, but little is known about the transmission mechanism of perceived justice that affects added value in PPP projects. Therefore, this research intends to investigate the link between perceived justice and PPP projects’ added value and their underlying mechanism by analysing the mediating role of cooperative behaviour.
Design/methodology/approach
Based on 246 valid survey data collected from the Chinese PPP professionals, structural equation modelling was adopted to analyse and test the proposed hypotheses.
Findings
The results show all three dimensions of perceived justice positively correlated with PPP projects’ added value. The influence effect from high to low was determined to be as follows: interactive, distributive and procedural justice. Moreover, both perfunctory and consummate performance were found to be positively correlated with and thus of great importance to PPP projects’ added value, but perfunctory performance was found to have a greater influence coefficient. The relationship between perceived justice and PPP projects’ added value is mediated by perfunctory and consummate performance. Therefore, the strategies of perceived justice in improving added value are verified in the context of Chinese PPP projects.
Research limitations/implications
The findings of this study can help realise added value in three ways. Firstly, new perspectives for PPP project added value should be proposed by combining the improvement of project basic objectives and the realisation of the participants’ implicit demands. Secondly, the effects of different perceived justice on added value should be analysed instead of a single dimension of perceived justice. Thirdly, the mediating effects of different types of cooperative behaviour that may influence the relationship between perceived justice and added value should be evaluated.
Practical implications
This study contributes to a better understanding of the relationship between perceived justice and PPP projects’ added value and provides a reliable reference for project managers to achieve added value outcomes in PPP projects. In addition, this study reveals the impact of perceived justice on PPP projects’ added value and the path of perceived justice transformation. This provides a useful reference for project managers to take advantage of the positive effects of distributive, interactive and procedural justice to enhance inter-organizational cooperative behaviour. This study thus helps improve the practice and value of PPP projects by using the right strategy of perceived justice.
Originality/value
The research clarifies the impacts of multidimensional perceived justice for added value of PPP projects throughout the implementation process. It offers a new perspective on PPP projects’ added value by combining the improvement of the realisation of participants’ implicit claims.
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Mengyuan Cheng, Guoliang Liu and Yongshun Xu
The role of conventional contracts in achieving sustainability goals in public–private partnership (PPP) projects has been questioned. From the multifunctional perspective of…
Abstract
Purpose
The role of conventional contracts in achieving sustainability goals in public–private partnership (PPP) projects has been questioned. From the multifunctional perspective of contract theory, joint-contract functions that combine contractual control, coordination and adaptation may be a potential approach for improving PPP project sustainability performance. This research intends to investigate the link between the joint-contract functions and PPP project sustainability performance, and their underlying mechanism, by analyzing the mediating role of relationship quality and moderating roles of environmental uncertainty and behavioral uncertainty.
Design/methodology/approach
Based on 170 valid survey data collected from the Chinese PPP professionals, partial least squares structural equation modeling (PLS-SEM) was adopted to test the hypothesis.
Findings
The results reveal that joint-contract functions are positively associated with the PPP project sustainability performance. This relationship is strengthened by environmental and behavioral uncertainty. Moreover, the relationship between the joint-contract functions and PPP project sustainability performance is mediated by relationship quality.
Research limitations/implications
This research extends contract governance theory and sustainability research in PPP projects. The research implications are as follows: (1) joint-contract functions are a second-order construct consisting of three first-order dimensions: control, coordination and adaptation and are positively associated with PPP project sustainability performance; (2) joint-contract functions enhance the sustainable benefits of PPP projects during environmental uncertainty and behavioral uncertainty; (3) informal relationships are a critical bridge connecting formal institutions with the sustainability performance of PPP projects.
Practical implications
In general, these findings guide project participants who aim to achieve sustainable outcomes in PPP projects. (1) Project participants should consider the process of contract design and sign contracts that focus on joint-contract functions. (2) Project participants should investigate the degree of uncertainty of a PPP project before designing contracts, and design the contracts with corresponding complexity. (3) Project participants should work to enhance PPP sustainable benefits by improving the relationship between partners, such as encouraging mutual trust and joint problem-solving.
Originality/value
This research verifies the relationship between joint-contract functions and PPP project sustainability performance, and the boundary and intermediary conditions between them.
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Kai-di Liu, Duo-Gui Yang, Guoliang Yang and Zhi-Tian Zhou
This paper aims to investigate the situation and evolution of sustainability performance in China.
Abstract
Purpose
This paper aims to investigate the situation and evolution of sustainability performance in China.
Design/methodology/approach
This paper adopts the global Malmquist-Luenberger (GML) productivity index based on data envelopment analysis and Tobit regression for analysis.
Findings
The results indicate the following: China’s sustainability performance has been improving since 2005 and is closely related to the national development strategy and supportive policy; regional gaps in sustainability are a prominent problem represented by the fact that South Central China is becoming a sustainability collapse zone; interprovincial heterogeneity is evident with the varying development speed and conditions; and the level of sustainability performance has a significantly positive correlation with the urbanization rate, investment completed in the treatment of industrial pollution, government appropriation for education and per capita area of paved roads, but it has a negative correlation with the possession of private vehicles.
Originality/value
As an application, this study assessing the GML productivity index of 30 provinces in China from 2005 to 2015 and analyse the sustainability performance on three regional levels (i.e. country level, regional level and provincial level). Tobit regression is also applied to recognize the factors related to the GML index with the results taken as references for policy suggestions. The results have implications for a comprehensive understanding of China's sustainability performance and policymaking in this field.
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Chunhua Qi, Guoliang Ma, Yanqing Zhang, Tianqi Wang, Erming Rui, Qiang Jiao, Chaoming Liu, Mingxue Huo and Guofu Zhai
The purpose of this paper is to present a transition detector (TD)-based radiation hardened flip-flop (TDRH-FF) for single event upset (SEU).
Abstract
Purpose
The purpose of this paper is to present a transition detector (TD)-based radiation hardened flip-flop (TDRH-FF) for single event upset (SEU).
Design/methodology/approach
With SEU recovery and single event transient (SET) detector mechanism, the TDRH-FF can tolerate SEU during hold mode and generate a warning signal for architecture-level recovery during transport mode when input signal contains SET. Evaluation results show that the TDRH-FF outperforms comparable comprehensive performance.
Findings
Simulation results show that 1) the mean pulse width of the correction glitches (at full width half maximum) of TDRH-FF is less than 10 ps; 2) the area overhead of TDRH-FF is similar to the EVFERST-FF, BISER-FF and DNURHL-FF; 3) TDRH-FF has the same average power consumption as SETTOF, and moderate PDP and Ps values among these compared FFs.
Originality/value
In this paper, a TD-based TDRH-FF is proposed to solve the problems in the previous design. And the main contributions of the proposed TDRH-FF are summarized: Minimum size transistors are used in the proposed TD which leads to a considerable decrease in area overheads and propagation delay (resulting in an ignorable correction glitch); and compared with other radiation hardened flip-flop, TDRH-FF outperforms comparable comprehensive performance.
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Nan Jiang, Kok Wei Khong, Jen Ling Gan, Jason James Turner, ShaSha Teng and Jesrina Ann Xavier
Nowadays, star athletes are global brand personalities. The increased popularity of the professional sport has contributed to elevating exceptional athletes to international star…
Abstract
Purpose
Nowadays, star athletes are global brand personalities. The increased popularity of the professional sport has contributed to elevating exceptional athletes to international star status. This empirical study aims to assess the impact of athlete performance and brand social value on product involvement with the mediation effect of celebrity athlete endorsement.
Design/methodology/approach
A quantitative survey was conducted with 399 Chinese participants. PLS-SEM is adopted to examine the associated paths and the mediating effect of celebrity endorsement.
Findings
The results demonstrate the significant impact of athlete performance and brand social value on product involvement. Celebrity endorsement partially mediates the effects of athlete performance and brand social value on product involvement.
Originality/value
This study extends understanding of celebrity athlete endorsement and provides insight into the strategic implications for Chinese social media-based marketing initiatives in the context of the recent Olympic Game in Tokyo 2021.