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This paper aims to study acoustic emission (AE) propagation characteristics by a crack under a moving heat source, which mainly provides theoretical basis and method for the actual crack detection during welding process.

The paper studied the AE characteristics in welding using thermoelastic theory, which investigates the dynamical displacement field caused by a crack and the welding heating effect. In the calculation model, the crack initiation and extension are represented by moment tensor as the AE source, and the welding heat source is the Gauss heat flux distribution. The extended finite element method (XFEM) is implemented to calculate and solve the AE response of a thermoelastic plate with a crack during the welding heating effect. The wavelet transform is applied to the time–frequency analysis of the AE signals.

The paper provides insights about the changing rule of the acoustic radiation patterns influenced by the heating effect of the moving heat source and the AE signal characteristics in thermoelastic plate by different crack lengths and depths. It reveals that the time–frequency characteristics of the AE signals from the simulation are in good agreement with the theoretical ones. The energy ratio of the antisymmetric mode A0 to symmetric mode S0 is a valuable quantitative inductor to estimate the crack depth with a certain regularity.

This paper mainly discusses the application of XFEM to calculate and analyze thermoelastic problems, and has presented few cases based on a specified configuration. Further work will focus on the calculation and analysis under different plate configurations and conditions, which is to obtain more interesting and general conclusions for guiding practice.

The paper is a successful application of XFEM to solve the problem of AE response of a crack in the dynamic welding inhomogeneous heating effect. The paper provides an effective way to obtain the AE signal characteristics in monitoring the welding crack.

Drawing on recent literature and empirical data, the purpose of this paper is to explore the relationships between perceived organizational support (POS), perceived overqualification (POQ) and turnover intentions (TI) in repatriates working in multinational corporations (MNCs).

Survey data were collected from 145 repatriates who had been contacted beforehand from MNCs in China. Structural equation modeling and hierarchical regression are used to examine the data.

It is shown that POQ and POS both affect repatriates TI, with POQ having the stronger effect, while POS plays a mediatory role between POQ and TI. Specifically, under the same POQ, repatriates TI will decrease as the POS increases.

The study design is cross-sectional and based on self-reporting, which makes causal explanations of the results difficult.

POQ and POS are both shown to influence TI, with POQ having the greater effect. This means managers can offset the effect of repatriates POQ on TI by providing better support and assistance, which can help MNCs reduce repatriates TI and retain employees.

This paper examines the antecedents of TI, and adds valuable new insights to the literature on repatriation through its research data, offering further evidence that managers in transnational corporations should pay more attention to organizational support policy on repatriates in order to reduce their turnover.

The purpose of this paper is to investigate farmers’ attitudes and behavior toward land titling and to study its potential effects on rural development.

Using household survey data collected from five provinces of China in 2010, this paper assesses farmer’s attitudes toward land titling and examines the potential effects of land titling on rural land transferring and labor migration.

Rural residential land titling has significant effects on farmers’ attitudes toward land transferring and their migration intention. Farmers who have more non-agricultural development opportunities are more likely to welcome land titling. The titling of rural residential land could provide secure property rights for farmers, and thus stimulate them to trade, mortgage their rural residential property, and migrate to urban areas.

Land titling in rural China will probably affect rural land transferring and encourage rural labor migrate to urban, and thus promote rural development.

This paper investigates farmers’ attitudes and behavior toward land titling, and examines its potential effects on rural land transferring and labor migration, based on national survey data. This paper sheds new lights on farmers’ demand for types of land tenure reforms and how these reforms would affect the perceived opportunities available for farmers.

Fault diagnosis methods based on blind source separation (BSS) for rolling element bearings are necessary tools to prevent any unexpected accidents. In the field application, the actual signal acquisition is usually hindered by certain restrictions, such as the limited number of signal channels. The purpose of this study is to fulfill the weakness of the existed BSS method.

To deal with this problem, this paper proposes a blind source extraction (BSE) method for bearing fault diagnosis based on empirical mode decomposition (EMD) and temporal correlation. First, a single-channel undetermined BSS problem is transformed into a determined BSS problem using the EMD algorithm. Then, the desired fault signal is extracted from selected intrinsic mode functions with a multi-shift correlation method.

Experimental results prove the extracted fault signal can be easily identified through the envelope spectrum. The application of the proposed method is validated using simulated signals and rolling element bearing signals of the train axle.

This paper proposes an underdetermined BSE method based on the EMD and the temporal correlation method for rolling element bearings. A simulated signal and two bearing fault signal from the train rolling element bearings show that the proposed method can well extract the bearing fault signal. Note that the proposed method can extract the periodic fault signal for bearing fault diagnosis. Thus, it should be helpful in the diagnosis of other rotating machinery, such as gears or blades.

This study is intended to investigate the current status of corporate universities in China. It aims to explore the processes and practices of corporate universities in China, and discover the issues and challenges involved in building and running a corporate university in China.

The heads of 11 well‐known corporate universities in China were interviewed. In addition, documentary data were also collected to triangulate with the interview data.

Compared with best practice corporate universities worldwide, the 11 corporate universities in this study have done well in three aspects, namely, learning initiatives support strategy and business goals, strong top management support, and leaders as teachers in management training programs. What needs improvement is the lack of a training evaluation mechanism.

The findings of this study provide a reference point for, and insights into, the processes and practices associated with corporate universities, and afford an opportunity to gain a better understanding of the issues and challenges involved in building and running a corporate university in China.

This study represents one of the first attempts to understand how a corporate university model works in the Chinese context. As such, it helps enrich the literature of corporate universities.

Crack and stress distribution on dies are key issues for the pressure-assisted sintering bonding of power modules. The purpose of this research is to build a relationship among stress distributions, sintering sequences and sintering pressures during the sintering processes.

Three sintering sequences, S(a), S(b) and S(c), have been designed for the double-side assembly of power module in this paper. Experiments and finite element method (FEM) analysis are conducted to investigate the crack and stress distribution.

The sintering sequence had significant effects on the crack generation in the chips during the sintering process under 30-MPa pressure. The simulation results revealed that the module sintered by S(a) showed lower chip stress than those by the other two sintering sequences under 30 MPa. In contrast, the chip stress is the highest when the sintering sequence follows S(b). The simulation results explained the crack generation and prolongation in the experiments. S(a) was recommended as the best sintering sequence because of the lowest chip stress and highest yield rate.

This study investigated the stress distributions of the double-side sintered power modules under different sintering pressures. Based on the results of experiments and FEM analysis, the best sintering sequence design is provided under various sintering pressures.

This paper aims to focus on the tracking of a moving magnetic target by using total field magnetometers and to present a tracking method based on the gradient of a magnetic anomaly. In the tracking, it is assumed that the motion of the target is equivalent to a first-order Markov process. And the unit direction vector of the magnetic moment from the gradient of the magnetic anomaly can be obtained. According to the unit direction vector, the inverse problem is turned into an optimization problem to estimate the parameters of the target. The particle swarm optimization algorithm is used to solve this optimization problem. The proposed method is validated by the numerical simulation and real data. The parameters of the target can be calculated rapidly using the proposed method. And the results show that the estimated parameters of the mobile target using the proposed method are very close to the true values.

The authors focus on the tracking of a moving magnetic target by using total field magnetometers and present a tracking method based on the gradient of a magnetic anomaly.

The paper provides an effective method for tracking the magnetic target based on an array with total field sensors.

Comparing with a vector magnetic sensor, the measurement of the scalar magnetic sensor is almost not influenced by its orientation. In this paper, a moving magnetic target was tracked by using total field magnetometers and a tracking method presented based on the gradient of a magnetic anomaly.

Focusing on the spillover effects between the CSI 500 stock index futures market and its underlying spot market during April to September 2015, the purpose of this paper is to explore whether Chinese stock index futures should be responsible for the 2015 stock market crash.

Using both linear and non-linear econometric models, this paper empirically examines the mean spillover and the volatility spillover between the CSI 500 stock index futures market and the underlying spot market.

The results showed the following: the CSI 500 stock index futures market has significant one-way mean spillover effect on its spot market. The volatility in CSI 500 stock index futures market also has a significant positive spillover effect on its spot stock market, and the mean value of dynamic correlation coefficient between the two market volatility is 0.4848. The spillover effect of the CSI 500 stock index futures market on the underlying spot market is significantly asymmetric, characterized by relatively moderate and slow during the period of the markets rising, yet violent and rapid during the period of the markets falling. The findings suggest that although the stock index futures itself was not the “culprit” of Chinese stock market crash in 2015, its existence indeed accelerated and exacerbated the stock market’s decline under the imperfect trading system.

Different from the existing literature mainly focusing on CSI 300 stock index futures, this paper empirically examines the impact of the introduction of CSI 500 stock index futures on 2015 Chinese stock market crash for the first time.

Developing nursing leadership has become a key policy priority to achieve universal health coverage. This study aims to explore the current status, developing trends and research frontiers in the field of nursing leadership.

In total, 1,137 articles and reviews on nursing leadership from 1985 to 2022 were retrieved from the Web of Science Core Collection database. Trends of publications, journals, countries/regions, institutions, documents and keywords were visualized and analyzed using Microsoft Excel and CiteSpace software.

Nursing leadership research showed an overall increase in number despite slight fluctuations in annual publications. The USA was the leading country in nursing leadership research, and the University of Alberta was the most productive institution. The Journal of Nursing Management was the most widely published journal that focused on nursing leadership, followed by the Journal of Nursing Administration. Keyword analysis showed that the main research hotspots of nursing leadership are improvement, practice and impact of nursing leadership.

This article summarizes the current state and frontiers of nursing leadership for researchers, managers and policy makers, as well as follow-up, development and implementation of nursing leadership. More research is needed that focuses on the improvement, practice and impact of nursing leadership, which are cyclical, complementary and mutually reinforcing. Longitudinal and intervention studies of nursing leadership, especially on patient prognosis, are also particularly needed.

To study the inhibition effect and mechanism of the Momordica charantia extract (BM) to 20 A carbon steel in 5 per cent HCl.

The weight loss, polarization curve, infrared spectrum (IR) analysis and X-ray photoelectron spectrum (XPS) analysis were carefully investigated to indicate the inhibition effect and mechanism of the BM to 20 A carbon steel in 5 per cent HCl.

BM was composed of C, N and O. Functional groups such as N–H and C=O were found in BM. The inhibition efficiency increased with the increasing concentration of BM. BM behaved as a mixed-type inhibitor, and the inhibition of BM to 20 A carbon steel might be its adsorption through the coordinate covalent bonding among the lone pair electrons of N and O and the empty 3d orbits of Fe, and the adsorption on the surface of 20 A carbon steel obeyed the Langmuir isotherm equation.

The inhibition of the BM to 20 A carbon steel in 5 per cent HCl.

BM could be used in 5 per cent HCl to prevent 20 A carbon steel from corrosion.

BM could be used in the chemical cleaning of the boilers to prevent the thermal equipments from corrosion.

The inhibition effect and mechanism of the BM to 20 A carbon steel were studied by the weight loss, polarization curve, IR analysis and XPS analysis. BM was composed of C, N and O. Functional groups such as N–H and C=O were found in BM. BM behaved as a mixed-type inhibitor. The inhibition efficiency increased with the increasing concentration of BM, and the adsorption on the surface of 20 A carbon steel obeyed the Langmuir isotherm equation.