Dongju Chen, Lihua Dong, Ri Pan, Jinwei Fan and Qiang Cheng
The purpose of this study is to investigate the coupling effects of the velocity slip, rarefaction effect and effective viscosity of the gas film on the performance of the…
Abstract
Purpose
The purpose of this study is to investigate the coupling effects of the velocity slip, rarefaction effect and effective viscosity of the gas film on the performance of the aerostatic guideway in micro-scale and improve the analysis precision of the static performance of aerostatic guideway.
Design/methodology/approach
The corresponding model of the gas film flow with consideration of the velocity slip, rarefaction effect and effective viscosity of the gas film in micro-scale is proposed. By solving the corresponding model, the bearing capacity and the stiffness of the aerostatic guideway are obtained through the pressure distributions of the air cavity. Through comparing the bearing capacity and the stiffness in different situations, the couple effects of the three factors are analyzed. Finally, the experimental results about the stiffness are obtained and the contrast between the simulation stiffness and the tested stiffness is achieved.
Findings
Through comparing the coupling effects of the micro scale factors under different conditions on the performance of the aerostatic guideway, it was found that when comparing the effects of a single factor, the effect of the first-order slip is the largest. When two factors are randomly combined, velocity slip and viscosity of the gas film is the largest, but these coupling effects are less than the effect of considering three factors simultaneously.
Originality/value
It is essential to consider the first-order velocity slip, the flow factor Q and the effective viscosity when analyzing the static performance of the aerostatic guideway in micro-scale. This makes studying the performance of the aerostatic guideway in micro-scale feasible and improves the machine’s accuracy.
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Yanqin Liu and Lihua Dong
The purpose of this paper is to apply a new modified homotopy perturbation method, which is effective to solve multi-order fractional equations with non-polynomial initial and…
Abstract
Purpose
The purpose of this paper is to apply a new modified homotopy perturbation method, which is effective to solve multi-order fractional equations with non-polynomial initial and boundary conditions.
Design/methodology/approach
The proposed algorithm is tested on multi-order fractional advection-dispersion equations. The fractional derivatives described in this paper are in the Caputo sense.
Findings
Approximate results explicitly reveal the complete reliability, efficiency and accuracy of the new modified technique.
Originality/value
It is observed that the approach may be implemented to other multi-fractional models with non-polynomial initial and boundary conditions.
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Bingjun Li, Shuhua Zhang, Wenyan Li and Yifan Zhang
Grey modeling technique is an important element of grey system theory, and academic articles applied to agricultural science research have been published since 1985, proving the…
Abstract
Purpose
Grey modeling technique is an important element of grey system theory, and academic articles applied to agricultural science research have been published since 1985, proving the broad applicability and effectiveness of the technique from different aspects and providing a new means to solve agricultural science problems. The analysis of the connotation and trend of the application of grey modeling technique in agricultural science research contributes to the enrichment of grey technique and the development of agricultural science in multiple dimensions.
Design/methodology/approach
Based on the relevant literature selected from China National Knowledge Infrastructure, the Web of Science, SpiScholar and other databases in the past 37 years (1985–2021), this paper firstly applied the bibliometric method to quantitatively visualize and systematically analyze the trend of publication, productive author, productive institution, and highly cited literature. Then, the literature is combed by the application of different grey modeling techniques in agricultural science research, and the literature research progress is systematically analyzed.
Findings
The results show that grey model technology has broad prospects in the field of agricultural science research. Agricultural universities and research institutes are the main research forces in the application of grey model technology in agricultural science research, and have certain inheritance. The application of grey model technology in agricultural science research has wide applicability and precise practicability.
Originality/value
By analyzing and summarizing the application trend of grey model technology in agricultural science research, the research hotspot, research frontier and valuable research directions of grey model technology in agricultural science research can be more clearly grasped.
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Bo Hu, Heng Zhou, Yubao Gui, Peng Zhai, Lihua Zhang and Zhiyan Dong
This paper aims to design a novel hybrid terrestrial-aerial robot, FlyingDog, including its modeling and implementation. By combining the complementary advantages of a quadrotor…
Abstract
Purpose
This paper aims to design a novel hybrid terrestrial-aerial robot, FlyingDog, including its modeling and implementation. By combining the complementary advantages of a quadrotor drone and a quadruped robot, FlyingDog demonstrates excellent maneuverability and high energy efficiency, showcasing great potential for applications in industrial inspection, field exploration, and search and rescue operations.
Design/methodology/approach
By integrating propellers and leg mechanisms, FlyingDog achieves hybrid motion, encompassing both aerial flight and ground movement. This paper first provides an overview of the robot’s structural design, emphasizing the minimization of interactions between the aerial and ground mechanisms while balancing the thrust-to-weight ratio and payload capacity. A distributed control framework is then proposed to achieve the hybrid motion, alongside the development of corresponding control strategies to ensure stability during various movements.
Findings
Experiments conducted in real-world conditions validated FlyingDog’s performance in terms of motion stability, energy efficiency, and obstacle-crossing ability. The results demonstrate that FlyingDog exhibits outstanding mobility by combining ground locomotion with aerial flight capabilities, allowing it to overcome challenging obstacles in purely ground-based mode. In ground mode, the robot achieved an energy efficiency of up to 93.5%.
Originality/value
The hybrid terrestrial-aerial robot presented in this paper features stable land and aerial mobility, a lightweight structure, high energy efficiency, and low manufacturing costs, making it a valuable innovation in the field of robotics.
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Lihua Cai, Shuo Dong, Xi Huang, Haifeng Fang and Jianguo She
Flexible mechanical gripper has better safety and adaptability than a rigid mechanical hand. At present, there are few soft grippers for small objects on a millimeter scale…
Abstract
Purpose
Flexible mechanical gripper has better safety and adaptability than a rigid mechanical hand. At present, there are few soft grippers for small objects on a millimeter scale. Therefore, the purpose of this paper is to design a soft pneumatic gripper for grasping millimeter-scale small and fragile objects such as jewelry and electronic components.
Design/methodology/approach
By simulating the clamping action of the bird’s mouth and combining the high flexibility of the soft material, the bird’s beak soft pneumatic gripper is designed. First, the internal cavity of the gripping end of the gripper is determined by bending deformation calculation, and the brief manufacturing process of the gripper is outlined. Then, the single finger of the soft gripper is modeled mechanically, and the relationship between air pressure and bending deformation of the single finger is obtained. Finally, the experimental platform of the soft mechanical gripper is built, and the gripping performance of silicone rubber material is tested by comparison test, bending deformation test, stability test, adaptability test and gripping accuracy test.
Findings
The designed gripper has the advantages of simple structure, convenient operation, easy grasping of different small objects of millimeter-scale and good adaptability. It can grasp the precise dispensing needle with a minimum diameter of 0.19 mm, and its accuracy meets daily use.
Originality/value
A new type of soft pneumatic, the mechanical gripper is proposed and manufactured. According to the shape of the bird’s beak and the calculation of bending performance, a hollow finger gripper with better bending performance is designed. Various test results show that the gripper has a significant clamping effect on millimeter small objects, which supplements the research field of millimeter small object gripper.
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Gaoyan Lyu, Lihua Chen and Baofeng Huo
The purpose of this paper is to examine the relationship between logistics park platforms, logistics location and operational performance. Relationship analysis helps managers…
Abstract
Purpose
The purpose of this paper is to examine the relationship between logistics park platforms, logistics location and operational performance. Relationship analysis helps managers respond to the changes that today’s logistics companies face, which include limited resources and facilities, market uncertainties and financial instabilities.
Design/methodology/approach
A structured questionnaire is developed based on the resource-based view. Qualitative data collected from 273 companies in China are used in a structural equation model to test the conceptual model.
Findings
In logistics parks, logistics park platforms and location positively influence companies’ resource integration, which is positively related to operational performance. While logistics park platforms can improve operational performance directly, logistics location cannot. Resource integration is thus a full mediator between logistics location and operational performance, while it is a partial mediator between logistics park platforms and operational performance.
Originality/value
This study fills a gap in the literature on logistics parks, particularly on the relationships among operational performance, resource integration, logistics park platforms and the location of logistics parks in China. The authors provide guidelines for logistics park managers to organize their resources and develop capabilities for improving the operational performance of companies in logistics parks.
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Fang Haifeng, Jun Zhang, Hanlin Sun and Lihua Cai
As a new type of spinning machine, the jet spinning machine absorbs the carding system of the rotating cup spinning series and the nozzle part of the jet spinning. This paper aims…
Abstract
Purpose
As a new type of spinning machine, the jet spinning machine absorbs the carding system of the rotating cup spinning series and the nozzle part of the jet spinning. This paper aims to intends to introduce the double carding structure currently studied by the rotating cup spinning into the jet spinning machine, and analyze the influence of the nozzle characteristic number on the flow field in the double carding structure to verify the advantages of the double carding structure.
Design/methodology/approach
The simulation is used to evaluate the performance of single/double split jet spinning and nozzle feature number, verify the technical advantages of double split jet spinning and evaluate the influence of nozzle feature number on flow field. The influence of the nozzle characteristic number on the flow pattern in the four models is compared. The advantages and disadvantages of a conventional single comb and a double comb with a bypass channel on the longer side of the transport channel as an additional air supply channel are also evaluated.
Findings
At present, the double comb technology of rotary cup spinning is being studied at home and abroad to improve the spinning quality and improve the difficult problem of mixed yarn with large difference in processing fiber properties. At present, the jet spinning machine combines the advantages of rotary cup spinning and jet spinning, absorbing the comb system of rotary cup spinning series and the nozzle part of jet spinning. Therefore, it is found that the introduction of the double-split structure into the wool jet spinning has research value to improve the spinning quality.
Originality/value
The purpose of this paper is to refer to the previous research on the double comb structure in rotary spinning, and to apply the double comb structure in the new jet spinning machine to improve the spinning quality. The simulation is used to evaluate the performance of single/double split jet spinning and nozzle feature number, verify the technical advantages of double split jet spinning and evaluate the influence of nozzle feature number on flow field.
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Jinyu Yang, Bin Liu and Lihua Yuan
This paper comes to the point from the tax competition of local government in investment promotion and capital introduction. This paper aims to empirically examine the internal…
Abstract
Purpose
This paper comes to the point from the tax competition of local government in investment promotion and capital introduction. This paper aims to empirically examine the internal mechanism of enterprises obtaining land resources from local government and its resulting equity investment increase and economic consequences of overinvestment.
Design/methodology/approach
The data of China’s A-share listed companies from 2007 to 2014 were used to test the relationship between the increase in enterprise equity investment and the acquisition of land resources and overinvestment. The descriptive statistics, correlation analysis and least squares linear regression were used to solve the above question.
Findings
One of the reasons for the enterprise equity increase is to obtain scarce land resources. The enterprise acquisition for land resources leads to overinvestment. The equity investment increase from obtaining land resources will further stimulate enterprise group to overinvest.
Research limitations/implications
The authors could not get the actual data of land that subsidiaries have obtained directly. In this research, the authors get the data using consolidated statements and subsidiary statements indirectly.
Practical implications
The results make contributions to the influencing factors and economic consequence of the enterprise investment structural deviation.
Social implications
It provides reference to optimize the “interaction” relationship between government and enterprises.
Originality/value
It identified the “dual-channel” conduction mechanism between land resource acquisition and enterprise overinvestment.
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Lihua Wang, Joel Nicholson and Jun Zhu
The purpose of this paper is to provide a comprehensive review and critique of what we already know about pay systems in Chinese state‐owned enterprises, to identify the gaps in…
Abstract
Purpose
The purpose of this paper is to provide a comprehensive review and critique of what we already know about pay systems in Chinese state‐owned enterprises, to identify the gaps in the literature and to stimulate more research in this area.
Design/methodology/approach
The paper first describes the policy issues at the macro‐level (government policies) in order to put micro‐level pay practices in a pertinent context. Then the paper provides a detailed review and critique on current empirical studies on pay practices in Chinese enterprises, their antecedents and consequences. Finally, the paper identifies potential research questions and provides some directions for future research.
Findings
The paper concludes from the extensive review of the current literature that the following research areas merit attention: Why do some firms pay their employees more than other firms? Why do we observe different types of internal pay structures among firms? What are the consequences of these different structures? Why is the link between pay and performance weak in some firms but strong in others? Under what conditions pay‐for‐performance enhances firm performance?
Originality/value
The paper is one of the most comprehensive reviews of the literature on compensation practices of Chinese companies.
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Lihua Fu, Yaxuan Wei, Ruijie Li, Yaokuang Li and Zhiying Liu
For survival and prosperity, enterprises need to simultaneously engage in exploitation and exploration. Digital transformation is of great significance to enterprise innovation…
Abstract
Purpose
For survival and prosperity, enterprises need to simultaneously engage in exploitation and exploration. Digital transformation is of great significance to enterprise innovation. However, the impacts of digital transformation on exploitation and exploration remain unclear. Moreover, the impacts of technological diversity on the relationships between digital transformation and exploitation and exploration are also unknown.
Design/methodology/approach
Based on an integrated perspective of dynamic capability theory and organizational inertia theory and using data from Chinese listed enterprises from 2007 to 2020, this study clarifies the effects of digital transformation on exploitation and exploration and assesses the moderating effect of technological diversity.
Findings
The results show that digital transformation improves exploitation, but negatively impacts exploration. Technological diversity mitigates the negative effect of digital transformation on exploration, but the moderating effect on the relationship between digital transformation and exploitation is not significant.
Originality/value
This study contributes to the existing literature on the digital paradox and provides guidance for enterprises to clarify the direction of digital transformation.