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This study aims to study the gas film stiffness of the spiral groove dry gas seal.

The present study represents the first attempt to calculate gas film stiffness in consideration of the slipping effect by using the new test technology for dry gas seals. First, a theoretical model of modified generalized Reynolds equation is derived with slipping effect of a micro gap for spiral groove gas seal. Second, the test technology examines micro-scale gas film vibration and stationary ring vibration to determine gas film stiffness by establishing a dynamic test system.

An optimum value of the spiral angle and groove depth for improved gas film stiffness is clearly seen: the spiral angle is 1.34 rad (76.8º) and the groove depth is 1 × 10^–5 m. Moreover, it can be observed that optimal structural parameters can obtain higher gas film stiffness in the experiment. The average error between experiment and theory is less than 20%.

The present study represents the first attempt to calculate gas film stiffness in consideration of the slipping effect by using the new test technology for dry gas seals.

The purpose of this paper is to analyze and improve the lubrication performance of a floating cylindrical seal by investigating micro spiral groove.

The lubrication model of is solved by finite difference, considering the influence of convergence eccentricity and Rayleigh step on the gas film period. A lubrication model, which is a gas film of floating microgroove cylindrical seal, is solved under high-precision central difference (finite-difference method-center) for the critical problems of convergence eccentricity and Rayleigh step. And then, an idea on the opening-leakage ratio is proposed, and a multiobjective optimization model is established. Finally, an experiment is conducted on a narrow gap to determine the gas film opening force and leakage by the modules of testing system, and the theoretical results are verified by real tests.

The theoretical calculation results agree well with the experimental data, which proves the correctness of the lubrication optimization model, and the optimized groove has better lubrication performance. On the other hand, the sealing pressure plays a more important role in the seal operation.

The theoretical model carries out low complexity and high sparseness, thus being very suitable for large-scale gas film problems. A multiobjective optimal function is established based on the opening-leakage ratio for optimizing groove. Finally, a curved groove of high precision and gas film opening force is obtained completely.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0048/

The purpose of this paper is to examine the relationship between bank diversity and small- and medium-sized enterprise (SME) firm innovation in China to evaluate the impact of recent bank deregulation.

Using a large data set that includes 8,143 firm-year observations of 1,122 listed SME firms in China and baseline and robustness regression analyses, the authors identify how bank diversity affects firm innovation and via what economic mechanisms. Potential endogeneity problems are considered and addressed in the design and analysis to minimize research bias.

The authors find robust evidence that bank diversity improves firm innovation. Specifically, the findings suggest that the positive effects of bank diversity on firm innovation are only significant for the firms which are more external finance dependent, have fewer growth opportunities and/or located in the provinces having low financial market development.

This study provides novel evidence and insights into the relationship between banking market structure and the determinants of firm innovation in the Chinese context, as a result of China’s banking deregulation.

The promotion of financial inclusion can disturb the composition of traditional bank concentration and change the relationship between bank concentration and the availability of small and medium-sized enterprise (SME) financing. This paper concentrates on a less frequently explored area of research by examining the relationships between bank concentration, financial inclusion and SME financing availability respectively, and the interaction between bank concentration and financial inclusion after the implementation of a financial inclusion strategy in China.

Using firm-level data from 1,509 listed SMEs in China from 2007 to 2017 and applying rigorous analyses, we identify how bank concentration affects SME financing availability under the promotion of financial inclusion and also the mechanisms involved.

We find that bank concentration and financial inclusion respectively have positive impacts on the credit available to listed SMEs, indicating that the promotion of financial inclusion in China has reached a new high watermark. The positive impact of bank concentration is reduced when the level of financial inclusion is high. Conversely, a higher level of financial inclusion favours SME credit availability at only a low degree of bank concentration. Our findings suggest that financial inclusion has a substitution effect on bank concentration and has enabled us to add new interpretations to relevant theories; namely, the Market Power and Information Theories respectively.

This study provides new insights into the relationship between bank concentration and SME finance availability under the promotion of financial inclusion.

The aim of the study is to obtain dense Ni-free CoCrW parts fabricated by selective laser melting (SLM) technique for dental application.

The optimum of processing CoCrW powders was investigated by the varying laser scanning speeds between 200 and 1,500 mm/s with the other parameters fixed as constants. The investigations of density, phase, mechanical property and corrosion resistance were conducted.

It was found that a maximum relative density of 99.4 per cent was obtained with the preferable laser scanning speed of 700 mm/s; the outcome from the tensile test suggested that the 0.2 per cent yield strength of the specimen fabricated at 700 mm/s satisfied the type 5 criteria in ISO22764 for dental application, whereas the electrochemical test indicated that the specimens fabricated at 700 mm/s existed excellent corrosion resistance. The high precision dental denture could be fabricated by SLM.

In the study, the Ni-free CoCrW parts fabricated by SLM was investigated by the tensile and electrochemical tests. The yield strength, corrosion resistance and margin fit accuracy met requirements for dental application. It was considered that the speed of 700 mm/s with the laser powers of 95 W, the track width of 0.11 mm and the layer thickness of 25 μm are promising candidates for fabricating the CoCrW parts.

This study aims to explore the innovative capabilities of building information modeling (BIM) in construction projects. The objectives are to construct an inclusive conceptual framework of BIM-enabled construction innovation, identify the status and trends of innovation-related research in BIM publications, synthesize research pertaining to BIM-enabled construction innovation and discover core research requirements in the related body of knowledge.

This study proposes a comprehensive theoretical framework, named innovation pyramid, comprising context, actor, artifact, process, structure and innovative task for exploring and analyzing the innovative capability of BIM in construction projects. Accordingly, mixed methods were used to perform a systematic review of research on the topic of BIM-enabled construction innovation.

The findings reveal that BIM innovation-related articles have predominantly considered BIM as an innovation from a technological standpoint, while the innovative capabilities of BIM have remained under-researched with a fragmented research focus. Fertile grounds for research have emerged and call for research pertaining to entities of “structure” and “innovative task” as well as interaction, interrelations and mutually adjusting effect among the entities.

The framework proposed may be useful for subsequent research design and for assisting project management practitioners in the use of BIM to achieve innovation more efficiently.

This research provides an insight into the innovative capabilities of BIM based on the BIM–collaboration–construction innovation logic chain. It contributes to the body of knowledge by devising an inclusive conceptual framework of BIM-enabled construction innovation, synthesizing the state of the art and exposing the research needs in this area.

This research paper aims to establish a comprehensive framework for the barriers to CER in the construction industry, assesses the barriers' relative degrees of hindrance and causal mechanisms.

Firstly, 26 carbon emission reduction (CER) barriers in the construction industry were identified based on a systematic literature review (SLR) and categorized into five dimensions: policy, economy, society, technology and organization (PEST + O model). Secondly, the Best–Worst Method (BWM) was used to clarify the degrees of hindrance of the CER barriers. Then, the Grey-Decision-Making Trial and Evaluation Laboratory (Grey-DEMATEL) was used to visualize the directional cause–result relationship network among prominent barriers. Finally, the Boston matrix model was used to propose differentiated strategies to address CER barriers in the construction industry.

The calculated centrality and causality of the prominent barriers indicated that the lack of relevant legal policies and normative guidelines, the poor binding force and enforcement of existing relevant policies, the lack of effective economic subsidies and incentives and the difficulty in the operation, transformation and upgrading of existing construction CER are the key barriers that CER needs to address first in the construction industry. Considering the order of priority and the optimal path, differentiated countermeasures are proposed to address key, driving, independent and effect barriers.

This study develops a BWM–Grey-DEMATEL integrated multi-criteria decision-making model. An innovative C-shaped strategic map for addressing CER barriers in the construction industry is proposed by integrating the dual dimensions of time and space. This will guide practitioners, policymakers and decision-makers in developing CER strategies.

The purpose of this paper is to conveniently and accurately design partial knitting knitted fabrics based on matrix transformation.

Using mathematical modeling, the pattern diagram block matrix and process design matrix of partial knitting knitted fabrics are established, and the process knitting diagram with parameter information is generated. Based on the establishment of the mathematical model of the process knitting diagram, a loop deformation method based on three-dimensional (3D) coordinate point matrix transformation is proposed.

The matrix transformation method can provide a suitable deformed loop mode for partial knitting knitted fabrics and helps to generate a 3D modeling diagram conveniently.

This paper proposed a method of design and modeling of partial knitting knitted fabric based on matrix transformation. Taking the 3D modeling effect of conventional partial knitting as an example to test the modeling method, the results show that after matrix transformation, the loop model can realize the rapid transformation and calculation of the coordinates of the control point and generate a 3D modeling diagram.

The purpose of this paper evaluates the effects of the Great Western Development (GWD) policy on agricultural intensification, land use, agricultural production and rural poverty in western China.

The authors collect county-level data on land use, input application, grain crop production, income, poverty and geophysical characteristics for 1996–2005 and use a quasi-natural experimental design of difference-in-differences (DD) in the empirical analysis.

Results suggest that the GWD policy significantly increased the grain crop production in western China. This increase resulted from higher yield, with increased fertilizer use and agricultural electricity consumption per hectare, and more land allocated to grow grain crops. The policy also increased land-use concentration, reduced crop diversity and alleviated rural poverty in western China.

This paper makes three contributions. First, the authors add to the growing literature on the GWD policy by evaluating its effects on farm household decisions and exploring the mechanisms and broad socioeconomic impacts in western China. Second, the authors take advantage of a quasi-natural experimental design to improve the identification strategy where input use, land allocation, production and off-farm labor participation are all endogenous in a farm household. Third, the authors explore a long list of variables within one integrated dataset to present a comprehensive picture of the impact of the GWD policy.

Fabric has complicated anisotropic mechanical behavior because of the woven pattern and complex physical properties. However, most current fabric simulation models are not satisfied because the models are usually geometrical models with stiffness parameters.

In this paper, the authors present a modeling technique to simulate fabric with Riemann manifold. The proposed nonlinear model is formed with ridge wave-curved surface based on the Riemann zero curvature, and the authors develop a solution to conserve the surface area. It decomposes the m × n matrix constituting the fabric into several batches and processes the fabric dots in batches. In this model, the distance between any two adjacent particles of the fabric's is assumed to be equal, and the area of the curved surface is always constant, and the inclination and decay of the ridge wave-curved surface are also considered.

As the result, the simulated shape is lifelike. In time cost performance, the model improves the efficiency of the fabric styling and meets the requirements of real-time simulation.

The proposed nonlinear model is formed with ridge wave-curved surface based on the Riemann zero curvature, and the authors develop a solution to conserve the surface area.