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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.

The purpose of this paper is to identify the impacts of financing constraints on the quality upgrading of China's agri-food sector.

Our empirical study is performed using the “distance to the frontier” framework. We employ a merged sample of Chinese agri-food trading firms based on Chinese firm-level data from the National Bureau of Statistics of China and Chinese customs data. To verify robustness, we test whether the results hold when using different definitions of quality upgrading and alternative proxy variables for product quality and financing constraints. To examine the heterogeneous effects, we generate subsamples by firm location, export destination and the product sophistication of exports.

The results suggest that financing constraints have a significant negative impact on the product quality upgrading of Chinese agri-food export firms. In addition, the negative impacts of financing constraints are more severe for firms close to the quality frontier than for those far from the frontier. These results are robust to various checks. Moreover, the heterogeneous effects of financing constraints on quality upgrading are identified when the sample is split according to firm location, export destination and the sophistication of export products.

This paper reviews and applies some recent studies in the literature to investigate the relationship between financing constraints and the product quality upgrading of agri-food export firms in China. Overall, the results of this paper could be considered of importance for promoting the quality upgrading of export products in the China's agri-food sector.

Due to climate change and an increasing concentration of the world’s population in vulnerable areas, how to manage catastrophe risk efficiently and cover disaster losses fairly is still a universal dilemma.

This paper applies a law and economic approach.

China’s mechanism for managing catastrophic disaster risk is in many ways unique. It emphasizes government responsibilities and works well in many respects, especially in disaster emergency relief. Nonetheless, China’s mechanism which has the vestige of a centrally planned economy needs reform.

I propose a catastrophe insurance market-enhancing framework which marries the merits of both the market and government to manage catastrophe risks. There are three pillars of the framework: (i) sustaining a strong and capable government; (ii) government enhancement of the market, neither supplanting nor retarding it; (iii) legalizing the relationship between government and market to prevent government from undermining well-functioning market operations. A catastrophe insurance market-enhancing framework may provide insights for developing catastrophe insurance in China and other transitional nations.

First, this paper analyzes China’s mechanism for managing catastrophic disaster risks and China’s approach which emphasizes government responsibilities will shed light on solving how to manage catastrophe risk efficiently and cover disaster losses fairly. Second, this paper starts a broader discussion about government stimulation of developing catastrophe insurance and this framework can stimulate attention to solve the universal dilemma.

This paper aims to study the impact of external fairness of executive compensation on M&A premium, and examine the moderate role of institutional investors. The high M&A premium is the main factors that induce the huge impairment of listed companies’ goodwill and the plummeting performance. Executives are the decision-makers of M&As, and their decision-making process is inevitably affected by the psychological factors. In recent years, institutional investors have become an important external force that can affect the governance of listed companies.

The authors use M&A data of listed companies from 2008 to 2018 and use OLS regression to test the relationship between executive compensation fairness and M&A premium.

The results show that the lower the external fairness of executive compensation, the greater the M&A premium. Institutional investors can effectively reduce the impact of external compensation unfairness on M&A premiums. The mechanism tests show that executives' psychological perception of fairness induced by external unfairness reduces their motivation to work and prompts them to use high premium to seek alternative compensation incentives. Further examinations of executive characteristics and corporate characteristics show that the role of external unfairness in executive compensation in driving M&A premiums is more pronounced in companies with longer executive tenure, weaker executive reputation incentives and private property.

This paper enriches the research on the pre-factors of M&A premiums from the perspective of executives’ psychological perception of fairness, provides evidence that institutional investors play a positive governance role and provides decision-making references for companies to take corresponding measures to reduce M&A premium risks.

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.

Urban water bodies play an important role in reducing summertime urban heat island (UHI) effects. Previous studies focused mainly on the impact of water bodies of large areas, and there is no analysis of the efficacy and scale effect of how small and medium-sized water bodies reduce the UHI effects. Hence, these studies could not provide theoretical support for the scientific planning and design of urban water bodies. This study aims to confirm, within different scale ranges, the efficacy of a water body in reducing the summertime UHI effects. We propose a scale sensitivity method to investigate the temporal and spatial relationship between urban water bodies and UHI. Based on the scale theory and geostatistical analysis method in landscape ecology, this study used the platforms of 3S, MATLAB, and SPSS to analyze the distance-decay law of water bodies in reducing summertime UHI effects, as well as the scale response at different water surface ratios. The results show that the influence of water surfaces on UHIs gradually decreases with increasing distance, and the temperature rises by 0.78 °C for every 100 m away from the water body. During daytime, there is a scaled sensitivity of how much water surfaces reduce the summertime UHI effects. The most sensitive radius from the water was found at the core water surface ratio of 200 m. A reduction of UHI intensity by 2.3 °C was observed for every 10% increase of the average core water surface ratio. This study provides a theoretical reference to the control of heat islands for the planning and design of urban water bodies.

This paper aims to determine whether domestic cotton support permitted by the current or potential World Trade Organization (WTO) rules would be sufficient to compensate the cost to China's cotton farmers if the sliding scale duty (SSD) on cotton imports is removed.

The simulation was conducted using a static spatial equilibrium model (SEM) of the world cotton market. First, a base model was specified to provide a good representation of the world cotton market's conditions. Second, simulations were conducted to evaluate the effects of replacing the SSD and subsidizing cotton producers pursuant to the current or potential WTO rules on domestic cotton support.

The results of the simulations suggest that China's cotton farmers are bound to incur losses. In either case, cotton subsidies permitted by the current or potential WTO rules are not sufficient to compensate for the cost to China's cotton producers if the SSD is eliminated.

It should be pointed out that these findings could suffer from a bias, primarily because the authors assumed that the WTO's blue box subsidies have no incentives for farmers to produce, and no substitution between cotton and alternative products. Thus, additional work is needed to reflect a more realistic situation in future studies.

The simulation estimation contributes to a better understanding of the issue of whether China should replace the current SSD with cotton subsidies to protect cotton producers.

The paper aims to fabricate an α-tricalcium phosphate (TCP) scaffold with an interconnected porous structure via selective laser sintering (SLS). To inhibit the phase transformation from β- to α-TCP in fabrication process of porous scaffolds, a small amount (1 weight per cent) of poly (L-lactic acid) (PLLA) is added into β-TCP powder to introduce the transient liquid phase.

The paper opted for the transient liquid phase of melting PLLA to decrease the sintering temperature in SLS. Meanwhile, the densification of β-TCP is enhanced with a combined effect of the capillary force caused by melting PLLA and the surface energy of β-TCP particles. Moreover, the PLLA will gradually decompose and completely disappear with laser irradiation.

The testing results show the addition of PLLA enables the scaffolds to achieve a higher β-TCP content of 77 ± 1.49 weight per cent compared with the scaffold sintered from β-TCP powder (60 ± 1.65 weight per cent), when the laser energy density is 0.4 J/mm2. The paper provides the mechanism of PLLA inhibition on the phase transformation from β- to α-TCP. And the optimum sintering parameters are obtained based on experimental results, which are used to prepare a TCP scaffold with an interconnected porous structure via SLS.

This paper shows that the laser energy density is an important sintering parameter that can provide the means to control the micro-porous structure of the scaffold. If the laser energy density is too low, the densification is not enough. On the other hand, if the laser energy density is too high, the microcracks are observed which are attributed to the volume expansion during the phase transformation from β- to α-TCP. Therefore, the laser energy density must be optimized.

The paper provides a feasible method for fabricating TCP artificial bone scaffold with good biological and mechanical properties.

The purpose of this paper is to provide readers with the main findings and conclusions of papers presented at the 2011 CAER‐IFPRI International Conference held under the theme “Is China entering a high food price era?”

The authors conduct a desk review of papers presented at the conference and provide a brief summary of the analytical tools, and main findings and conclusions of each presentation.

These reviews show that, while there seems to be an increase in the prices of agricultural commodities on the Chinese market, in real terms, these rises fall far below the increases in the prices of industrial commodities. Thus, expert views remain divided on whether China is entering an era of high food price.

The discussions initiated by the conference theme aroused researchers' curiosities for further studies into understanding the current level of food prices in China.