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The purpose of this study is to address the issue that the traditional V-shaped ball valve profile shape is limiting the flow control characteristics in a series structure and to optimize the design profile by proposing an open-hole profile.

This paper proposes a Gaussian process regression surrogate model based on the genetic algorithm optimization of swarm intelligence, combined with the Expected Improvement point addition criterion, to optimize and correct the design profile. The flow regulation performance of the optimized V-shaped regulating ball valve is verified through a combination of numerical simulation and experiment.

The results demonstrate that the optimized V-shaped regulating ball valve has higher flow regulation accuracy and a more stable flow regulation process. After optimization, the flow characteristic curve of the spool is closer to the ideal equal percentage characteristic. The simulation results of the flow field are consistent with the experimental results.

The proposed method significantly reduces the optimization time, has higher efficiency and solves the problem that traditional optimization methods struggle with, which is ensuring optimal flow regulation performance. Compared to the traditional trial-and-error optimization method, the proposed method is more effective. The feasibility of the method is supported by experimental results.

With continuous concerning on the toxic of element Pb, Pb-free solder was gradually used to replace traditional Sn-Pb solder. However, during the transition period from Sn-Pb to Pb-free solder, mixing of Sn-Pb and Pb-free is inevitable occurred in certain products, and in China where Sn-Pb solder was still used extensively in certain areas especially. Correspondingly, understanding reliability of Sn-Pb solder joints was very important, and further studies were needed.

Thermal shock test between −55°C and 125 °C was conducted on Sn-37Pb solder bumps in the BGA package to investigate the microstructure evolution and the growth mechanism of interfacial intermetallic compound (IMC) layer. The effects of thermal shock on the mechanical property and fracture behavior of Sn-37Pb solder bumps were discussed.

Pb-rich phase was coarsened and voids were increased at first; Pb-rich phase was refined and voids were decreased secondly with the increase of thermal shock cycles; the shear strength of solder bumps was slightly decreased after thermal shock, but was back up to 73.67MPa at 2,000 cycles; interfacial IMCs of solder bumps was from typical scallop-type into smooth, the composition of IMCs was from Cu₆Sn₅ into Cu₆Sn₅ and Cu₃S_n after thermal shock with 1,500 and 2,000 cycles; 20.0 per cent of solder bumps at 1,500 cycles and 9.5 per cent of solder bumps at 2,000 cycles were failure respectively.

Compared with the board level test method, the impact shear test for the single solder bump is more convenient and economical and is actively pursued by the industries. The shear strength of solder bumps was slightly decreased after thermal shock, but was back up to 73.67 MPa at 2,000 cycles; 20.0 per cent of solder bumps at 1,500 cycles and 9.5 per cent of solder bumps at 2,000 cycles were failure.

This paper presents the application of grey modeling for thermal spray processing parameter analysis in less data environment.

Based on processing knowledge, key processing parameters of thermal spray process are analyzed and preselected. Then, linear and non-linear grey modeling models are integrated to mine the relationships between different processing parameters.

Model A reveals the linear correlation between the HVOF process parameters and the characterization of particle in-flight with average relative errors of 9.230 percent and 5.483 percent for velocity and temperature.

The prediction accuracies of coatings properties vary, which means that there exists more complex non-linear relationship between the identified input parameters and coating results, or more unexpected factors (e.g. factors from material side) should be further investigated.

According to the modeling case in this paper, method has potential to deal with other diverse modeling problems in different industrial applications where challenge to collecting large quantity of data sets exists.

It is the first time to apply grey modeling for thermal spray processing where complicated relationships among processing parameters exist. The modeling results show reasonable results to experiment and existing processing knowledge.

This study aims to identify and analyse the gains and strains associated with flexible working practices (FWPs) introduced and adopted prior to and during the pandemic and consider how these experiences are likely to shape the future of workplace flexibility post-pandemic.

A case study research strategy was adopted to explore the FWPs implemented by a state-owned organisation in the Chinese publishing industry. A mixed data collection method was used. Quantitative data was collected from 50 valid questionnaires, which was followed by 7 qualitative interviews to gain rich insights into the availability and effectiveness of various FWPs and associated benefits and drawbacks.

While the results confirm positive effects FWPs have on employee engagement and retention and on business continuity and employee well-being during the pandemic, the empirical analysis highlights the performance-driven patterns in use and impacts of some FWPs, which caused concerns and dilemmas. Besides the increasing intense market competition, the changing face of state-owned enterprises and managerial attitudes have been found to have significant effects on the use of FWPs.

This paper has contributed to a better understanding of flexible working in an under-researched setting, reflected in changes before and during the pandemic, offering an insight into the commercialised nature of flexible working in the Chinese context. It has implications for organisations and HR practitioners as they envision future workplace flexibility.

This paper explores the profound philosophical and conceptual foundations that underpin comparative international education research, particularly concerning the evolving roles of universities and colleges that transcend mere skills training or human capital development in contemporary times. Universities and colleges have predominantly focused on measuring their success through criteria such as research excellence and their ability to adapt to the ever-evolving demands of the job market. It is imperative to recognize that the diversity of postsecondary institutions is not only providers of human capital with curriculum shaped by labor market needs; rather, they should be recognized as institutions dedicated to human development, community anchors, the promotion of the public good, democratic education, the cultivation of civil society, and global citizenship. Relying on an extensive review of selected literature pertaining to the mission, goals, aims, and roles of the postsecondary sector in three regions (East Asia, Germanic Europe, and North America), this paper considers the question, “How do different approaches and traditions in different social contexts contribute to our understanding of the civic roles of postsecondary education institutions in shaping future global citizens, transcending the confines of national boundaries?” Throughout the paper, the unique contexts and traditions of these regions are meticulously examined alongside thematic discussions, culminating in comprehensive analyses on what factors are considered as the civic roles of institutions and what challenges are there for them to realize their goals.

The purpose of this paper is to reveal the dynamical behavior of higher dimensional nonlinear wave by searching for the multi-wave solutions to the (3+1)-D Jimbo-Miwa equation.

The authors apply bilinear form and extended homoclinic test approach to the (3+1)-D Jimbo-Miwa equation.

In this paper, by using bilinear form and extended homoclinic test approach, the authors obtain new cross-kink multi-soliton solutions of the (3+1)-dimensional Jimbo-Miwa equation, including the periodic breathertype of kink three-soliton solutions, the cross-kink four-soliton solutions, the doubly periodic breather-type of soliton solutions and the doubly periodic breather-type of cross-kink two-soliton solutions. It is shown that the extended homoclinic test approach, with the help of symbolic computation, provides an effective and powerful mathematical tool for solving higher dimensional nonlinear evolution equations in mathematical physics.

The research manifests that the structures of the solution to higher dimensional nonlinear equations are diversified and complicated.

The methods used in this paper can be widely applied to the research of spatial and temporal characteristics of nonlinear equations in physics and engineering technology. These methods are also conducive for people to know objective laws and grasp the essential features of the development of the world.

As a new type of spinning machine, the jet spinning machine absorbs the carding system of the rotating cup spinning series and the nozzle part of the jet spinning. This paper aims to intends to introduce the double carding structure currently studied by the rotating cup spinning into the jet spinning machine, and analyze the influence of the nozzle characteristic number on the flow field in the double carding structure to verify the advantages of the double carding structure.

The simulation is used to evaluate the performance of single/double split jet spinning and nozzle feature number, verify the technical advantages of double split jet spinning and evaluate the influence of nozzle feature number on flow field. The influence of the nozzle characteristic number on the flow pattern in the four models is compared. The advantages and disadvantages of a conventional single comb and a double comb with a bypass channel on the longer side of the transport channel as an additional air supply channel are also evaluated.

At present, the double comb technology of rotary cup spinning is being studied at home and abroad to improve the spinning quality and improve the difficult problem of mixed yarn with large difference in processing fiber properties. At present, the jet spinning machine combines the advantages of rotary cup spinning and jet spinning, absorbing the comb system of rotary cup spinning series and the nozzle part of jet spinning. Therefore, it is found that the introduction of the double-split structure into the wool jet spinning has research value to improve the spinning quality.

The purpose of this paper is to refer to the previous research on the double comb structure in rotary spinning, and to apply the double comb structure in the new jet spinning machine to improve the spinning quality. The simulation is used to evaluate the performance of single/double split jet spinning and nozzle feature number, verify the technical advantages of double split jet spinning and evaluate the influence of nozzle feature number on flow field.

Due to the rapid pace of development and innovation in information technology, the dedicated electronic book (e‐book) reader has become a new trend in reading. However, at present there is only a limited understanding of what factors drive user attitudes/willingness to use this new device for reading. Hence, this paper aims to explore what factors drive users to use dedicated e‐book readers for reading.

The study proposes a causal model that explores how convenience, compatibility, and media richness affect users' attitudes towards the dedicated e‐book readers for reading.

The results of this study suggest that convenience, compatibility, and media richness all significantly contribute to dedicated e‐book reader acceptance.

The study extends previous theories: the Technology Acceptance Model, Innovation Diffusion Theory, media richness theory and convenience. This helps one to better understand what factors affect usage of the dedicated e‐book readers, an important topic for current and future research.

The findings outline and describe how the dominant factors affect users' attitudes towards adoption of the dedicated e‐book readers for reading. By considering factors such as ease‐of‐use, usefulness, convenience, compatibility, media richness, etc., in the stage of product development, practitioners can provide dedicated e‐book readers that customers will readily accept.

These findings will enable development of a more robust understanding of attitudes toward dedicated e‐book readers and will be helpful to developers researching e‐book hardware and software as well as to researchers interested in testing related theories.

This chapter examines the similarities and differences between the concepts of transformational leadership as developed within North America and the Confucian idea of transformation. It argues that Confucian tradition encompasses the essential elements embedded in the concept of transformational leadership. The former differentiates from the latter in its deeper degree of transformation, emphasis on morality and culture, and its focus on transformation from the inside outwards. The two greatest educators in Chinese history, Confucius and Cai Yuanpei, are evaluated in terms of their transformational leadership qualities in the Western sense. By looking at Confucius and Cai Yuanpei as successful transformational leaders, the chapter identifies four important factors from Chinese cases that may contribute to the success of this type of leadership. Implications of this comparison are discussed as they may inform the knowledge, research and practices of transformational leadership.