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The purposes of this paper are to study the characterization of drill bit breakage in printed circuit board (PCB) drilling process based on high-speed video analysis and to provide an important reference for micro drill bit breakage prediction.

Based on PCB drilling experiment, the high-speed camera was used to observe the micro drill breakage process and the chip removal process. The variation of chip in the drilling process was studied and one of the key reasons for the drill bit breakage was analysed. Finally, the swing angles’ feature during the breakage process of the micro drill was analysed and researched with the image processing tools of MATLAB.

The micro drill was prone to breakage mainly because of the blocked chips. The breakage process of the micro drill can be divided into the stage of stable chips evacuation, the stage of blocked chips and the stage of drill bit breakage. The radians of swing angles were basically in the range of ±0.01 when the drilling possess is normal. But when the radians of swing angles considerably exceeded the range of ±0.01, the micro drill bit may be fractured.

This paper presented the method to study the characterization of drill bit breakage in the PCB drilling process by using high-speed video analysis technology. Meanwhile, an effective suggestion about monitoring the radians of swing angles to predict the breakage of micro drill bit was also provided.

The purpose of this paper is to investigate the effects of surface topography, including surface roughness, circumferential waviness and radial taper, on hydrodynamic performance of liquid film seals considering cavitation.

A mathematical model of liquid film seals with surface topography was established based on the mass-conservative algorithm. Liquid film governing equation was discretized by the finite control volume method and solved by the Gauss–Seidel relaxation iterative algorithm, and the hydrodynamic performance parameters of liquid film seals were obtained considering surface roughness, circumferential waviness and radial taper separately.

The results indicate that the values of load-carrying capacity and frication torque are affected by the surface topography in varying degrees, but the effect is limited.

The results presented in the study are expected to aid in determining the optimum value of structural parameters for the optimum seal performance because of the realistic model which considers both surface topography and cavitation.

In this paper, a kind of an oil groove structure which could improve the transmission torque of an oil film was designed, i.e. the width and depth of oil groove gradually decrease with the increase in the radius.

Effects of the structural parameters of the oil groove on the hydro-viscous drive (HVD) characteristics with variable rotational speed were investigated by means of numerical calculation.

Research results show that with the decrease of the width and depth of the oil groove at the outer diameter, transmission torque increases, while the temperature is almost unchanged. Keeping the effective area unchanged, comparing the transmitted torque under the oil groove angle θ₂ = 0.5° and θ₂ = 4.5°, the former was almost 200 per cent of the latter; the torque transmitted with h₂ = 0.05 mm was almost 150 per cent of that with h₂ = 0.2 mm.

In this paper, the authors analyze the friction surface of the friction plate between the oil groove, oil distribution and oil film transfer torque from the oil groove structure parameters and found methods to improve the transmission torque. For the first time, the influence of the structural parameters of oil groove on the characteristics of HVD was studied under the condition of variable rotational speed, and a better method to improve the transmission torque was proposed.

The purpose of this study is to explore organizational social media capability in business-to-business (B2B) marketing, by focusing on what social media capability is in a B2B marketing context and how it is developed in firms engaged in B2B marketing.

This is a thematic literature review, drawing on both B2B marketing and Information Systems literature. In total, 112 academic articles from nine journals were identified and analyzed. The findings were synthesized and compiled to provide answers to the predefined research questions.

The results suggest that organizational social media capability is dependent on a deep understanding of a firm’s technological capability, i.e. recognizing the key features and categories of social media and dynamically upgrading the recognition in response to the environmental change. A four-level Social Media Capability Maturity Model (technological, operational, managed and strategic level) that collectively transfers social media’s technological capability to dynamic organizational capability is proposed.

This study contributes to an understanding of the use of social media in the context of B2B marketing from an organizational dynamic capability perspective. The model is particularly relevant to organizations that have adopted or plan to adopt a B2B social media strategy and is relevant for B2B researchers who are interested in social media research.

The purpose of this paper is to study the working characteristics of hydro-viscous clutch at high rotational speeds and obtain the trend of flow field variation of oil film.

The FLUENT simulation model of the oil film between the friction disks is built. The effect of variation of working parameters such as input rotational speed, oil flow rate and film thickness on two-phase flow regime and transmission torque is studied by using the volume of fluid model.

The results show that the higher the rotational speed, the severer the cavitation is. In addition, the two-phase flow region makes the coverage of oil film over the friction pairs’ surface reduce, which results in a decrease in transmission torque for the hydro-viscous clutch.

These simulation results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for power transmission mechanism of oil film by considering the existence of a two-phase flow regime consisting of oil and air.

The purpose of this paper is to investigate the effect of boundary slip on hydrodynamic performance of liquid film seal considering cavitation.

A mathematical model of liquid film seal with slip surface was established based on the Navier slip model and Jakobsson–Floberg–Olsson (JFO) boundary condition. Liquid film governing equation was discretized by the finite difference method and solved by the SOR relaxation iterative algorithm and the hydrodynamic performance parameters of liquid film seal were obtained considering boundary slip and cavitation.

The results indicate that the values of performance parameters are affected significantly by the slip length under the condition of high speed and low differential pressure.

The performances of liquid film seal are investigated considering slip surface and cavitation. The results presented in the study are expected to provide a theoretical basis to improve the design method of liquid film seal.

The purpose of this study is to analyze the effect of foreign direct investment (FDI) on pollution emissions and how environmental regulation affects this relationship.

In the empirical research, the authors selected panel data for 30 provinces in China from 2005 to 2019 as samples. First, the authors used the instrumental variable method to verify the existence of the above hypotheses in China. Then, the authors analyzed the moderating effect of different types of environmental regulations on the environmental effects of FDI. Next, in further discussion, the authors analyzed the difference between the environmental effect and the moderating effect in different time periods and regions, respectively. Finally, the authors discussed whether the different intensities of environmental regulations lead to the transfer effect of FDI in choosing investment destinations.

The result shows that FDI can help reduce pollution emissions and create a “pollution halo” effect, which is enhanced by command-and-control regulation but suppressed by market-based incentives. The heterogeneity analysis reveals that the 18th National Congress of the Communist Party has weakened the pollution halo effect of FDI, while the environmental effect of FDI in the eastern region is not significant, but in the middle and western regions, there is a significant pollution halo effect and a positive moderating effect of environmental regulations. Finally, further analysis reveals that FDI has a transfer effect under command-and-control environmental regulations.

First, the main purpose of this paper is to study the relationship between FDI and pollution emissions from the perspective of heterogeneous environmental regulation. Therefore, there is no detailed discussion on their effect mechanism of them. Second, limited by data, the authors adopt the single index to measure the stringency index of command-and-control and market-based incentive environmental regulations in China. The single index may not be able to fully reflect the intensity of regional environmental regulation, so the construction of a composite indicator is necessary. These shortcomings are the focus of the authors' future research.

Under the guidance of high-quality development, the conclusions above can provide reference for adjusting FDI policies and improving environmental regulation policies.

The innovations in this paper can be summarized as the following four dimensions: First, the authors use the instrumental variable (IV) method to address endogeneity in the relationship between FDI and pollution emission, which can further ensure the robustness of the research results and increases the credibility of the paper. Second, the authors distinguish between two types of environmental regulations to investigate their moderating effect on the environmental impact of FDI. Third, the authors consider the temporal and spatial heterogeneity of both the environmental effects of FDI and the moderating effect of regulation. Last, the authors analyze the spatial spillover of environmental regulation through the study of the transfer effect.

Under different ground motion excitation modes, the spatial coupling effect of seismic response for the arch bridge with thrust, seismic weak parts and the internal force components of the control section of main arch ribs are analyzed.

Taking a 490 m deck type railway steel truss arch bridge as the background, the dynamic calculation model of the whole bridge was established by SAP2000 software. The seismic response analyses under one-, two- and three-dimension (1D, 2D and 3D) uniform ground motion excitations were carried out.

For the steel truss arch bridge composed of multiple arch ribs, any single direction ground motion excitation will cause large axial force in the chord of arch rib. The axial force caused by transverse and vertical ground motion excitation in the chord of arch crown area is 1.4–3.6 times of the corresponding axial force under longitudinal seismic excitation. The in-plane bending moment caused by the lower chord at the vault is 4.2–5.5 times of the corresponding bending moment under the longitudinal seismic excitation. For the bottom chord of arch rib, the arch foot is the weak part of earthquake resistance, but for the upper chord of arch rib, the arch foot, arch crown and the intersection of column and upper chord can all be the potential earthquake-resistant weak parts. The normal stress of the bottom chord of the arch rib under multidimensional excitation is mainly caused by the axial force, but the normal stress of the upper chord of the arch rib is caused by the axial force, in-plane and out of plane bending moment.

The research provides specific suggestions for ground motion excitation mode and also provides reference information for the earthquake-resistant weak part and seismic design of long-span deck type railway steel truss arch bridges.

The purpose of this paper is to study the temperature characteristics of hydro-viscous clutch with different structure of friction disks and obtain the distribution of film temperature.

The mathematical model of oil film between friction disks with radial grooves is established. Based on the flow rate equation, the temperature rise equation of oil film is deduced. Considering two-phase flow, the temperature distribution in the oil shear stage and the effects of the ratio of inner radius to outer radius on film temperature rise is studied by using computational fluid dynamics (CFD) technology.

The results show that when input speed is constant, the increase in the ratio of inner to outer radius leads to an increase in the peak temperature and the decrease in the ratio results in a larger increasing rate of temperature.

These results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for the mechanism of temperature rise by considering the effect of two-phase flow.

Based on an organizational capability perspective, this paper aims to propose a development model for social media analytics (SMA) capability that can be applied to business-to-business (B2B) marketing, with the aim of facilitating the use and integration of SMA in B2B marketing and maximizing the benefits of business networks in the age of social media.

This is a critical interpretive synthesis of SMA publications collected from academic journals, business magazines and the SMA service industry. In addition, an inter-disciplinary approach was adopted by drawing upon both marketing and information systems literature. In total, 123 academic papers, 106 industry case studies and 141 magazine papers were identified and analyzed. The findings were synthesized and compiled to address the predefined research question.

An SMA capability development model is proposed. The proposed model consists of four inter-dependent levels (technological, operational, managed and strategic) that collectively transfer the technological capability of SMA to the dynamic organizational capability. Each level of SMA capability is detailed. SMA-in-B2B marketing is highlighted as a socio-technical phenomenon, in which a technological level SMA capability is emphasized as the foundation for developing organizational level SMA capabilities and organizational capabilities, in turn, supporting and managing SMA activities and practices (e.g. strategic planning, social and cultural changes, skills and resources, measurements and values).

The proposed research framework may have implications for the operational level SMA development and the investigations on the direct and/or indirect measurements to help firms see the impact of SMA on their business.

This study may have implications for the adoption, use, integration and management of SMA in B2B marketing. The proposed model is grounded on the integrated insights from academia and industry. It is particularly relevant to B2B firms that have engaged in or plan to engage in applying SMA to extract insights from their online networks and is relevant to B2B researchers who are interested in SMA, big data and information technology organization integration studies.