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In this study, the Models-3/Community Multiscale Air Quality Model (CMAQ) coupled with the Mesoscale Modeling System Generation 5 (MM5) was employed to simulate the air pollution episodes over East Asia, northern China Plain (NCP), and southern Hebei (SHB), at a grid resolution of 36, 12, and 4 km, respectively in Oct. 2012. The PM₁₀ concentrations over SHB at 12-km are overpredicted with NMBs of 34.6% to 45.7% and also overestimated with that of 72.1% to 97.5% at 4-km which applied such a fine grid resolution over the SHB for the first time. It indicated that the simulation at 12-km performs better than the 4-km which may be related to the spatial allocation of the emissions, the lack of dust emissions and the limitations of model treatments. Five heavy episodes show the characteristics of sawtooth-shaped cycles over the NCP in fall (i.e. the maximum of PM₁₀ was up to 885.1 µg m⁻³ and PM_2.5 was up to 438.4 µg m⁻³ in Handan city) which resulting in the deterioration of visibility and periodically haze days. The concentrations of OC, EC, SO₄²⁻, NO₃⁻ and NH₄⁺ were significantly higher in heavy episodes than non-heavy pollution episodes. In comparison with other cities ([NO₃⁻]/[SO₄²⁻] > 1) at 12-km, the monthly-mean mass ratio of [NO₃⁻]/[SO₄²⁻] at Taiyuan (0.17−0.73), Shijiazhuang (0.28−2.34) was 0.43, 0.84 respectively, which means the stationary sources emissions were more important than the vehicle emission in the source areas. The influence of the regional transportation for pollutants compared with local emission was also an important factor for heavy pollution episodes. The regional joint framework should be established along with controlling the local emission over the SHB in China to improve the air quality.

In the wake of the COVID-19 health crisis, destinations are facing the challenging task of reopening their borders while keeping resident population safe. Destination communities help to flatten the infection curve while tourists contribute to spread the virus. This chapter explores the impacts of a health crisis on stakeholders' emotional solidarity and support for tourism. Twenty-six semi-structured interviews were conducted with different stakeholders. Findings show that informants who perceive socioeconomic tourism benefits are likely to support it in exchange for appropriate health measures. Others affected sociopsychologically by the pandemic feel negative emotional solidarity toward foreign tourists. Thus, delineating the role of a health crisis becomes a crucial research question that can contribute to academic understanding of support for tourism. As uncertainty over border reopening currently affects 24% countries worldwide, these findings can be relevant to policymakers.

The purpose of this paper is to explore the emergence of civil disobedience (CD) movements in Hong Kong in the context of the notion of civil society (CS).

The paper begins by rigorously defining the notion of CD, as well as the concept of CS and tracing its development in Hong Kong over the past several decades. By using a model of CS typology, which combines the variables of state control and a society’s quest for autonomy (SQA), the paper aims to outline the historical development of CD movements in Hong Kong. It also discusses the recent evolution of CS and its relationship with CD movements, particularly focusing on their development since Leung Chun-ying became the Chief Executive in 2012. Finally, by using five cases of CD witnessed in the past several decades, the relationship between the development of CS and the emergence of CD in Hong Kong has been outlined.

Four implications can be concluded: first, CD cannot emerge when the state and society are isolated. Second, the level of SC and the scale of CD are positively related. Third, as an historical trend, the development of SQA is generally in linear progress; SQA starts from a low level (e.g. interest-based and welfare-based aims) and moves upwards to campaign for higher goals of civil and political autonomy. If the lower level of SQA is not satisfied, it can lead to larger scale CD in future. Fourth, the CD movement would be largest in scale when the state-society relationship confrontational and when major cleavages can be found within CS itself.

This paper serves to enrich knowledge in the fields of politics and sociology.

The purpose of this paper is to unpack the black box of post-merger and acquisition (M&A) integration of reverse M&A by Chinese multinational enterprises (MNEs).

This research adopts multiple cases of Chinese reverse M&A. Data are collected using the approaches of in-depth interviews, storytelling and narratives.

This research identifies various antecedents underlying Chinese post-M&A integration, such as asymmetries in resources, capabilities, vision and status between Chinese MNEs and acquired firms. The post-M&A integration process of Chinese reverse M&A consists of a top-down effortless integration initiated by Chinese MNEs with both benefits and problems, and a bottom-up reverse integration conducted by acquired firms.

By linking the pre-M&A phase and the post-M&A phase, this research builds a new model of post-M&A integration of Chinese reverse M&A from an indigenous Wu Wei paradigm. The new model counterpoises extant literature, shifting from the task and efficiency-focussed view to the people and harmony-focussed view.

The purpose of this paper is to examine the impact of media attention on corporate disaster relief.

The authors used a matched sample research design, which is considered more appropriate than a random sample design for studying events that have low-occurrence rates in general. For each donor firm in the Yushu earthquake, the authors matched the firm with a non-donor firm in the same industry and with a firm size of within ±30 percent of the total assets in the year prior to the year of the occurrence of the Yushu earthquake. Then, using the Baidu engine, which is the most popular Chinese search engine, the authors captured the online media attention to the donor firms and their disaster relief.

The authors found that media attention drove corporate disaster relief.

Although the authors highlighted the role of the media as an important stakeholder in influencing corporate disaster relief, the authors did not fully explore the media’s influence. Future research should delve more deeply into the impact of the tenor of media coverage on corporate disaster relief.

This study reveals that the media, a particularly powerful stakeholder, can be a corporate disaster relief driver in China.

The aim of this study is to understand thermal effects and surface topography of roller bearings with misaligned load under combination of multifactors by an experimental method.

A series of orthogonal experiments would need to be planned and performed. A ranking of impact degree of factors on edge effect and eccentric load effect can be learned with multivariate analysis of variance by Statistical Product and Service Solutions software. Influence rules of each individual factor can also be obtained through more experiments. A roller surface phase diagram both before and after test can be observed with metallographic microscope. An axial profile data of roller can be measured by PGI 3D Profiler, then a roller generatrix contour can be achieved through filtering measured signal with empirical mode decomposition method.

Slip fraction has most impact on edge effect, whereas tilting angle plays a key role in eccentric load effect. For the case of low temperature, skidding damage does not occur. Inversely, because of the high pressure in partial elastohydrodynamic lubrication caused by roller tilt, running-in occurs and micro asperity flattening is observed on a rough surface. And, the larger the tilting angle, the more obvious the micro-flattening and the greater the reduction of roller surface roughness after the test.

A lot of theoretical studies on thermal effect of roller bearings surface morphology have been published. However, there are little on relevant experimental study, especially on thermal effect with an integration of sliding, tilting and unbalance loading.

In high-speed processing, the influence on the machining accuracy of a machine tool is greatly caused by the thermal deformation of the motorized spindle; a further study on the thermal characteristics of the spindle is given in this paper. This study aims to reduce the thermal error and improve the performance of the machine tool by discussing the relationships between the temperature distributions and rotating accuracy caused by the thermal deformations of the spindle.

The paper opted for a method combining the theoretical analysis and the experimental study to study the thermal stability of the high-speed motorized spindle. First of all, a finite element model of the spindle was built with ANSYS, whereby temperature distributions and the thermal deformations were successively obtained at different speeds. And then, both the temperature field and the rotating accuracy of the motorized spindle were measured simultaneously by the thermal stability experiment. Finally, the experimental and theoretical results were compared and validated.

The thermal stability of the motorized spindle was studied in this paper, and some findings from the study were as follows: the spindle’s rotating accuracy maintained good in X direction but bad in Y and Z directions in terms of the deformations; the higher front-end temperature of the spindle which can significantly affect the rotating accuracy is needed to be controlled mainly; the recovery speed of the spindle deformation lagged behind the temperature’s fallback speed; the vibration graph about radial rotating sensitivity synthesized by X1 and X2 presented a trifoliate shape.

Based on a built test-bed which can synchronously measure the motorized spindle’s temperature distribution and rotating accuracy with five-point method, the coupling effects of the thermal deformation and temperature are embodied, and not only the vibration graph but also the thermal tilt angles can be gained. Therefore, considering the influence of the thermal deformation on the heat generated by the bearings, the paper fulfilled a study by which it was obtained that the front-end temperature of the spindle, which was higher and could significantly affect the rotating accuracy, needed to be controlled mainly.

This paper aims to numerically investigate the magnetohydrodynamic (MHD) convection heat transfer of nanofluid inside a differentially heated enclosure with various fin morphologies.

The fluid flow within the cavity was governed by N-S equations while it within porous medium was solved by the non-Darcy model, called the Darcy–Forchheimer model based on representative element-averaging method. Empirical correlations from experimental data are used to evaluate the effective thermal conductivity and dynamic viscosity. Relevant governing parameters, including thermal Rayleigh number (10⁵-10⁷), Hartmann number (0-50), Darcy number (10⁻⁶-10⁻¹), thermal conductivity ratio of porous matrix (1-10³), nanoparticles volume fraction (0-0.04) and topology designs of porous fins, are sensitively varied to identify their effects and roles on the fluid flow and heat transfer. Particularly, heatlines are used to investigate the mechanism of heat transport.

Numerical results demonstrate that the predictions of average Nusselt number are augmented by using more porous fins with high permeability, and this effect becomes opposite in tiny Darcy numbers. Particularly, for high Darcy and Rayleigh numbers, the shortest fins could achieve the best performance of heat transfer. In addition, the prediction of average Nusselt number reduces with an increase in Hartmann numbers. An optimal nanoparticles concentration also exists to maximize heat transfer enhancement. Finally, numerical correlations for the average Nusselt number were proposed as functions of these governing parameters.

Present work could benefit the thermal design of electronic cooling and thermal carriers in nanofluid engineering.

Present work could benefit the thermal design of electronic cooling and thermal carriers in nanofluid engineering. In addition, optimum thermal removals could enhance the lifetime of electronics, therefore reducing the cost of energy and materials.

To the best knowledge of authors, there are not any studies considering the synergetic effects of porous fins on MHD convection of nanofluids. Present work could benefit the thermal design of electronic cooling and thermal carriers in nanofluid engineering.

This paper aims to design a novel test device and study the wear properties and the thermal mechanisms of roller pairs in dual-freedom sliding contacts.

On the transition process of lubrication regimes, experiments were conducted with various values of running speed and slip ratio obtained by two motorized spindles. Temperature and surviving time would be obtained of GCr15/GCr15 and DLC/GCr15 friction pairs. Micro photography was obtained with a PGI 3D stylus profiler and a confocal microscopy OLS4000-3D. An empirical mode decomposition method was used to eliminate measure errors.

Results showed that, even with little initial lubricant, rolling/sliding pairs still rotated for a certain time. With the synthetic actions of the dual-freedom sliding, the loss of lubrication and the tilt, interesting helical grooves appeared. Sliding speeds had remarkable effects on survive time, temperatures and surface topographies. In addition, the equilibrium values of the temperature and the surface roughness were obtained in sufficient oil supply. Extreme wear-out conditions were obtained with starved lubrication. Diamond-like carbon coatings showed better heat resistance and better wear resistance.

This work would be critical for the life design and the heat treatment of rolling bearings in the full flood lubrication and the starved lubrication.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0164/