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This paper aims to present an adaptive fuzzy sliding mode controller with nonlinear observer (AFSMCO) for the redundant robotic manipulator handling a varying payload to achieve a precise trajectory tracking in the task space. This approach could be applied to solve the problems caused by the dynamic effect of the varying payload to robotic system caused by model uncertainties.

First, a suitable observer using the recursive algorithm is presented for an accurate estimation of external disturbances caused by a variable payload. Second, the adaptive fuzzy logic is designed to approximate the parameters of the sliding mode controller combined with nonlinear observer (SMCO) to avoid chattering in real time. Moreover, Lyapunov theory is applied to guarantee the stability of the proposed closed-loop robotic system. Finally, the effectiveness of the proposed control approach and theoretical discussion are proved by simulation results on a seven-link robot and demonstrated by a humanoid robot platform.

The varying payload leads to large variations in the dynamics of the manipulator and the tracking error. To achieve high-precision position tracking, nonlinear observer was introduced to feed into the sliding mode control (SMC) which had improved the ability to resist the external disturbance. In addition, the chattering caused by the SMC was eliminated by recursively approximating the switching gain with the usage of adaptive fuzzy logic. Therefore, a distributed control strategy solves the problems of an SMC implementation in improving its tracking performance and eliminating the chattering of the system control.

The AFSMCO is proposed for the first time and used to control the redundant robotic manipulator that handles the varying payload. The proposed control algorithm possesses better robustness and higher precision for the trajectory tracking than classical SMC.

In this study, superhydrophobic fabric is prepared with a wet-chemical coating technique that uses a coating solution synthesized by the co-hydrolysis and co-condensation of tetraethyl orthosilicate and fluoroalkyl silane (tridecafluorooctyl triethoxysilane) under an alkaline condition. The treated fabric shows stable superhydrophobicity with a water contact angle as high as 171°, and a sliding angle as low as 2°. The coated fabric has higher repellency to saline water, and its repellency increases with increases in the salt content in the solution. The contact angle is reduced with increases in liquid temperature. When the water temperature is 90°C, the contact angle on the superhydrophobic fabric is 153°. The superhydrophobic treatment slightly reduces the air permeability, but increases the water vapor permeability of the fabric. The treatment considerably increases the liquid breakthrough pressure, but has little effect on fabric pore size and thermal conductivity. The air gap membrane distillation process is used to evaluate the desalination performance of the superhydrophobic fabric. When the feed and the condenser are kept at 90°C and 20°C, respectively, the membrane distillation (MD) system with the superhydrophobic fabric yields a permeate flux of water up to 13.8 kg m^-2 hour^-1, which is slightly higher than that with the use of polymer and inorganic MD membranes reported. Superhydrophobic fabrics may thus be considered as effective MD membranes for water desalination applications.

The purpose of this paper is to study the tribological behavior and mechanism of water‐soluble bismuth dithiophosphate as the additive of water‐based cutting fluid in aluminum alloy tapping.

Comparable investigation has been made on the lubrication performance of bismuth dithiophosphate and sodium dithiophosphate in aluminum alloy tapping. The aluminum alloy‐machined surface finish was observed on scanning electron microscope. The films on the work‐piece‐machined surface and the tap tool working surface were analyzed by X‐ray photoelectron spectroscopy.

The results indicated that the water medium containing 1 wt% the prepared water‐soluble bismuth dithiophosphate exhibited better tapping efficiency than the liquid paraffin containing 2.5 wt% chlorinated paraffin and 2.5 wt% sulfurized olefin. The bismuth sulfide component in the reaction film on the tap working surface plays a leading role in elevating the tapping efficiency and improving the machined surface finish.

The paper is restricted to the lubrication performance of bismuth dithiophosphate as the water‐based cutting fluid additive in 2024 aluminum alloy tapping.

The test method adopted is very close to the machined method applied in industry. The test results show that the bismuth dithiophosphate can obviously improve the tapping efficiency and the machined surface finish. Thus, it can be applied to the aluminum alloy cutting in automotive and aviation.

An attempt has been made to identify the chemical reaction film sourced from bismuth element and dithiophosphate group on the work‐piece‐machined surface and the tool working surface and their contribution to enhancing the tapping efficiency and improving the machining surface finish. This is helpful to the designers and the practitioners of the additives of metalworking fluid.

The purpose of this paper is to present a dual-mode online optimization method (OOM) for trajectory tracking of the redundant manipulators. This method could be used to resolve the problem of the kinematics redundancy effectively when the manipulator moves in a limited space or its movements go through a singular point.

In the proposed method, the physical limits of the manipulator in the torque level is considered as inequality constraints for the optimal scheme. Besides, a dual-mode optimal scheme is developed to yield a feasible input in each control period during the path tracking task of the manipulator, especially when it moves under the limited space or around the singular point. Then, the scheme is formulated as a quadratic programming; the computationally efficient quadratic programming solver based on interior method is formulated to solve the kinematic redundancy problem.

The traditional pseudo inverse method (PIM) for the kinematic resolution to the redundant manipulator has some limitations, such as slow computation speed, unable to take joint physical limits into consideration, etc. Relatively, the OOM could be used to conquer the deficits of the PIM method. Combining with the dual-mode optimal scheme and considering the physical constraints in the torque level, the online method proposed in this paper is more robust and efficient than the existing method.

In this paper, dual-mode OOM is first proposed for the resolution of the kinematics redundancy problem. Specific design of its model and the discussion of its performance are also presented in this paper.

The purpose of this paper is to understand the effect of base media on the tribological performance and tribochemistry of bismuth thiophosphate additive.

The oil‐water double soluble additive bismuth dithiophosphate was prepared and identified. The contributions of the two base media on the additive tribological behavior and the tribofilm components were comparatively studied.

The extreme pressure (EP) and friction‐reducing properties are remarkably improved with water substituted for paraffin as the base medium. The EP performance of the lubricating media containing this additive mainly results from the tribochemical reaction film on the rubbing surface, not from the viscosity of the base media. In water or paraffin medium, the adsorption process of this additive from the lubricant bulk onto the rubbing surface and the components and the properties of the tribochemical reaction films formed are different, which have important effect on the tribological performance.

The paper mainly focuses on how the water medium with polarity and the liquid paraffin base medium with non‐polarity affect on the tribological performance of the bismuth thiophosphate additive.

The research has found a water‐oil double soluble lubrication additive with outstanding EP and friction‐reducing performance.

The designed experiment provides a new approach to further learn the action mechanism of thiophosphate additive.

Sometimes regarded as the best method of prioritizing budgetary expenditures, Zero-Based Budgeting (ZBB) was introduced into China in the early 1990s and systematically adopted since the recent budgeting reform although it has experienced numerous failures in many countries. This study examines ZBB as practiced in Hubei province in China. In Hubei, although the reformers are intended to create ZBB as a general budgeting framework, eventually, it was a Chinese style Target-Based Budgeting (TBB) rather than ZBB that has been put into place. Interestingly, ZBB has not disappeared but is deliberately applied to budgetary decisions of one type of expenditures under the Chinese style TBB. However, even in the field where ZBB is practiced, its achievements are at best moderate. The Chinese experiment of ZBB presents something new not only for the theory of ZBB but also for the budgeting literature.

Although an important facet of modernist architecture in which function plays a prominent role, building flexibility is not entirely a new concept. Its relevance transcends generations, allowing space and structure to evolve through time. This paper investigates the relationship among main building structures, infill elements, and space by studying examples in ancient Chinese architecture. It reveals the role of building owners, users, and craftsmen from a survey of historical documentation. In studying these examples, it is concluded that craftsmen in ancient China were involved not only during the construction phase but throughout the period of use as well. Thus, in select cases, the relationship between craftsmen and owners or users had been preserved for generations. Finally, this paper suggests potential strategies for the building industry and technology in the move towards sustainable development.

The study aims to the distribution rule of lubricating oil film of full ceramic ball bearing and improve its performance and life.

The paper established an analysis model based on the fluid–solid conjugate heat transfer theory for full ceramic ball bearings. The distribution of flow, temperature and pressure field of bearings under variable working conditions is analyzed. Meanwhile, the mathematical model of elastohydrodynamic lubrication (EHL) of full ceramic ball bearings is established. The numerical analysis is used to study the influence of variable working conditions on the lubricant film thickness and pressure distribution of bearings. The temperature rise test of full ceramic ball bearing under oil lubrication was carried out to verify the correctness of simulation results.

As the speed increased, the oil volume fraction in full ceramic ball bearing decreased and the surface pressure of rolling element increased. The temperature rise of full ceramic ball bearings increases with increasing speed and load. The lubricant film thickness of full ceramic ball bearing is positively correlated with speed and negatively correlated with load. The pressure of lubricating film is positively correlated with speed and load. The test shows that the higher inner ring speed and radial load, the higher the steady-state temperature rise of full ceramic ball bearing. The test results are in high agreement with simulation results.

Based on the fluid–solid conjugate heat transfer theory and combined with Reynolds equation, lubricating oil film thickness formula, viscosity temperature and viscosity pressure formula. The thermal analysis model and EHL mathematical model of ceramic ball bearings are established. The flow field, temperature field and pressure field distribution of the full ceramic ball bearing are determined. And the thickness and pressure distribution of lubricating oil film in the contact area of full ceramic ball bearing were determined.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0126/

Focusing on the important representative of firm intellectual capital (IC), this research explores the effects of chief executive officer’s (CEOs') managerial human capitals on sustaining superior performance in Chinese transition economy to prove the dynamic and strategic value of IC and fulfill the gap of lacking emerging market studies in this research field.

Based on dynamic managerial capability theoretical framework, the authors propose a dynamic management path to analyze the influencing mechanism of CEOs' managerial human capitals to firm performance persistence and the moderating effect of environment uncertainty. Using a panel data of Chinese publicly listed firms from 2008 to 2017, it adopts dynamic first-order autoregressive models to examine these hypotheses. Several tests are conducted to further analyze and ensure that the results are robust and reliable.

These managerial human capitals reveal heterogenous impacts on sustaining superior performance, and environment uncertainty is a valid moderating variable to further distinguish their dynamic values. The supplementary analyses show the integrating effect of an MBA degree and output functional experience is positive and significant, and the results in Chinese state-owned and private firm subsamples are distinct.

It is beneficial for corporate stakeholders to judge and select CEOs and for policymakers to improve the efficiency advantage of IC in Chinese emerging market.

This study first explores the relationship between CEOs' managerial human capitals and superior performance persistence. Through introducing a dynamic perspective, it has extended existing performance persistence research into individual level and provided a new intellectual source of sustainable competitive advantages.