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3D steady heat conduction analysis considering heat source is conducted on the fundamental of the fast multipole method (FMM)-accelerated line integration boundary element method (LIBEM).

Due to considering the heat source, domain integral is generated in the traditional heat conduction boundary integral equation (BIE), which will counteract the well-known merit of the BEM, namely, boundary-only discretization. To avoid volume discretization, the enhanced BEM, the LIBEM with dimension reduction property is introduced to transfer the domain integral into line integrals. Besides, owing to the unsatisfactory performance of the LIBEM when it comes to large-scale structures requiring massive computation, the FMM-accelerated LIBEM (FM-LIBEM) is proposed to improve the computation efficiency further.

Assuming N and M are the numbers of nodes and integral lines, respectively, the FM-LIBEM can reduce the time complexity from O(NM) to about O(N+ M), and a full discussion and verification of the advantage are done based on numerical examples under heat conduction.

(1) The LIBEM is applied to 3D heat conduction analysis with heat source. (2) The domain integrals can be transformed into boundary integrals with straight line integrals by the LIM. (3) A FM-LIBEM is proposed and can reduce the time complexity from O(NM) to O(N+ M). (4) The FM-LIBEM with high computational efficiency is exerted to solve 3D heat conduction analysis with heat source in massive computation successfully.

The purpose of this paper is to investigate the relationships between different types of team goal orientations (team learning orientation, team prove orientation and team avoid orientation) and team performance in new product development (NPD) and how these relationships are mediated by team absorptive capacity.

Data were collected through two surveys from 71 NPD teams and analyzed by the confirmatory factor analysis, correlation and hierarchical regression analysis methods.

The authors find that both teams’ learning and prove orientations are positively related to their absorptive capacity, which leads to increasing team performance in NPD. Further, the authors find support for the mediating role of team absorptive capacity in connecting team learning orientation and team prove orientation with team performance in NPD.

For practitioners, this paper suggests that to benefit from their NPD team efforts, firms with innovative aspirations should consider their existing and desired access to external knowledge sources and particularly the extent to which they can successfully integrate external knowledge with their internal knowledge structure.

The explication of team absorptive capacity is as a key mechanism through which different goal orientations of NPD teams inform the ability to successfully develop new products. By integrating the concepts of team goal orientations, team absorptive capacity and team performance in NPD, the authors seek to gain a better understanding of why some firms are more likely to do better than others in NPD. Findings of this paper extend concept of the nomological network on how absorptive capacity may serve as a direct outcome of different goal orientations. This paper responds to how Chinese firms can increase their innovative performance by infusing their current knowledge bases with external knowledge and extends the literature on knowledge management and managerial ties on innovation.

This paper aims to discover a highly efficient corrosion inhibitor for 45# steel in hydrochloric acid solution and reveal the mechanism of inhibitors.

In this paper, electrochemical measurements, weight loss measurements, surface characterization and theoretical calculation are used to evaluate the inhibition performance and reveal the mechanism of inhibitors.

Results show that didecyl dimethyl ammonium chloride (DDAC), especially in combination with dodecane phenol plyoxyethylene, could provide a good protection performance for the carbon steel in hydrochloric acid. The N atoms and long alkyl chains in DDAC molecular structure play the vital role.

Usually, DDAC is used as the compound chemical disinfectant in oilfield sterilization, medicine and health. However, to the best of the authors’ knowledge, no study has shown that it can mitigate the corrosion of carbon steels in HCl solution.

Long life and high hydrogen sensitivity are the crucial performance parameters for an optical fiber hydrogen sensing membrane, and these are the fundamental areas of study for an optical fiber hydrogen sensor. Considering that a traditional optical fiber hydrogen sensor based on pure palladium cannot meet the expectations for long life and rapid sensitivity simultaneously, the experiment in this paper designed a kind of reflective optical fiber bundle hydrogen gas sensor based on a Pd_0.75–Ag_0.25 alloy to achieve a hydrogen sensing system. This paper aims to discuss the issues with this system.

A reflective optical fiber bundle hydrogen sensor was made up of an optical fiber bundle and a Pd_0.75–Ag_0.25 alloy hydrogen membrane. A combination of optical fiber light intensity measurements and the reference calculation method were used to extract the hydrogen concentration information from within the optical fiber, and the relationship between the hydrogen concentration changes and the reflective light intensity in the optical fiber was established.

The reflective optical fiber bundle hydrogen gas sensor based on a Pd–Ag alloy membrane was shown to provide an effective way to detect hydrogen concentrations. The experimental results showed that a 20-30-nm-thick Pd_0.75–Ag_0.25 alloy membrane could reach high hydrogen absorption and sensitivity. Key preparation parameters which included sputtering time and substrate temperature were used to prepare the hydrogen membrane during the DC sputtering process, and the reflectivity of the Pd–Ag alloy membrane was enough to meet the requirements of long life and high hydrogen sensitivity for the optical fiber hydrogen sensor.

This paper seeks to establish a foundation for optimizing and testing the performance of the Pd–Ag alloy hydrogen sensing membrane for an optical fiber bundle hydrogen sensor. To this end, the optimal thickness and key preparation parameters for the Pd–Ag alloy hydrogen sensing membrane were discussed. The results of this research have proved that the reflective optical fiber hydrogen sensor based on a Pd_0.75–Ag_0.25 alloy is an effective approach and precisely enough for hydrogen gas monitoring in practical engineering measurements.

The paper aims to expand the scope of application of the lattice Boltzmann method (LBM), especially in the field of aircraft engineering. The traditional LBM is usually applied to incompressible flows at a low Reynolds number, which is not sufficient to satisfy the needs of aircraft engineering. Devoted to tackling the defect, the paper proposes a developed LBM combining the subgrid model and the multiple relaxation time (MRT) approach. A multilayer adaptive Cartesian grid method to improve the computing efficiency of the traditional LBM is also employed.

The subgrid model and the multilayer adaptive Cartesian grid are introduced into MRT-LBM for simulations of incompressible flows at a high Reynolds number. Validated by several typical flow simulations, the numerical methods in this paper can efficiently study the flows under high Reynolds numbers.

Some numerical simulations for the lid-driven flow of cavity, flow around iced GLC305, LB606b and ONERA-M6 are completed. The paper presents the investigation results, indicating that the methods are accurate and effective for the separated flow after icing.

LBM is developed with the addition of the subgrid model and the MRT method. A numerical strategy is proposed using a multilayer adaptive Cartesian grid method and its treatment of boundary conditions. The paper refers to innovative algorithm developments and applications to the aircraft engineering, especially for iced wing simulations with flow separations.

This paper aims to investigate the anti-icing performance of the nanosecond dielectric barrier discharge (NSDBD) plasma actuator.

With the Lagrangian approach and the Messinger model, two different ice shapes known as rime and glaze icing are predicted. The air heating in the boundary layer over a flat plate has been simulated using a phenomenological model of the NSDBD plasma. The NSDBD plasma actuators are planted in the leading edge anti-icing area of NACA0012 airfoil. Combining the unsteady Reynolds-averaged Navier–Stokes equations and the phenomenological model, the flow field around the airfoil is simulated and the effects of the peak voltage, the pulse repetition frequency and the direction arrangement of the NSDBD on anti-icing performance are numerically investigated, respectively.

The agreement between the numerical results and the experimental data indicates that the present method is accurate. The results show that there is hot air covering the anti-icing area. The increase of the peak voltage and pulse frequency improves the anti-icing performance, and the direction arrangement of NSDBD also influences the anti-icing performance.

A numerical strategy is developed combining the icing algorithm with the phenomenological model. The effects of three parameters of NSDBD on anti-icing performance are discussed. The predicted results show that the anti-icing method is effective and may be helpful for the design of the anti-icing system of the unmanned aerial vehicle.

The purpose of this paper is to investigate thermohydraulic characteristics of turbulent flow of water (4,000 = Re = 10,000) in a rectangular channel equipped with perforated chevron plat-fin (PCPF) with different vortex generators (VGs) shapes.

First, three general shapes of VGs including rectangular, triangular and half circle, are compared to each other. Then, the various shapes of rectangular VGs, (horizontal, vertical and square) and triangular VGs, (forward, backward and symmetric) are evaluated. To comprehensively evaluate the thermohydraulic performance of the PCPF with various VG shapes, the relationship between the Colburn factor and the friction factor (j/f) is presented, then a performance index (η) is applied using these factors.

Results show that the enhanced models of the PCPF, which are equipped with VGs, have higher values of j/f ratio and η as compared with the reference model (R). Further, the half-circle VG with the lowest pressure drop values (about 2.4% and 4.9%, averagely as compared with the S and ST vortex generators), shows the highest thermohydraulic performance among the proposed shapes. The maximum of performance index of 1.14 is found for the HC vortex generator at Re = 4,000. It is also found that the square and forward triangular VGs, have the best thermohydraulic performance among the rectangular and triangular VGs respectively and the highest performance index of 1.13 and 1.11 are reported for these VGs.

The thermohydraulic performance of the PCPF with different vortex generators VGs shapes have been investigated.

The purpose of this paper is to propose a novel jump control method based on Two Mass Spring Damp Inverted Pendulum (TMS-DIP) model, which makes the third generation of hydraulic driven wheel-legged robot prototype (WLR-3P) achieve stable jumping.

First, according to the configuration of the WLR, a TMS-DIP model is proposed to simplify the dynamic model of the robot. Then the jumping process is divided into four stages: thrust, ascent, descent and compression, and each stage is modeled and solved independently based on TMS-DIP model. Through WLR-3P kinematics, the trajectory of the upper and lower centroids of the TMS-DIP model can be mapped to the joint space of the robot. The corresponding control strategies are proposed for jumping height, landing buffer, jumping attitude and robotic balance, so as to realize the stable jump control of the WLR.

The TMS-DIP model proposed in this paper can simplify the WLR dynamic model and provide a simple and effective tool for the jumping trajectory planning of the robot. The proposed approach is suitable for hydraulic WLR jumping control. The performance of the proposed wheel-legged jump method was verified by experiments on WLR-3P.

This work provides an effective model (TMS-DIP) for the jump control of WLR-3P. The results showed that the number of landing shock (twice) and the pitch angle fluctuation range (0.44 rad) of center of mass of the jump control method based on TMS-DIP model are smaller than those based on spring-loaded inverted pendulum model. Therefore, the TMS-DIP model makes the jumping process of WLR more stable and gentler.

This paper aims to propose a method to solve the problem of localization and mapping of a two-wheeled inverted pendulum (TWIP) robot on the ground using the Stereo–inertial measurement unit (IMU) system. This method reparametrizes the pose according to the motion characteristics of TWIP and considers the impact of uneven ground on vision and IMU, which is more adaptable to the real environment.

When TWIP moves, it is constrained by the ground and swings back and forth to maintain balance. Therefore, the authors parameterize the robot pose as SE(2) pose plus pitch according to the motion characteristics of TWIP. However, the authors do not omit disturbances in other directions but perform error modeling, which is integrated into the visual constraints and IMU pre-integration constraints as an error term. Finally, the authors analyze the influence of the error term on the vision and IMU constraints during the optimization process. Compared to traditional algorithms, the algorithm is simpler and better adapt to the real environment.

The results of indoor and outdoor experiments show that, for the TWIP robot, the method has better positioning accuracy and robustness compared with the state-of-the-art.

The algorithm in this paper is proposed for the localization and mapping of a TWIP robot. Different from the traditional positioning method on SE(3), this paper parameterizes the robot pose as SE(2) pose plus pitch according to the motion of TWIP and the motion disturbances in other directions are integrated into visual constraints and IMU pre-integration constraints as error terms, which simplifies the optimization parameters, better adapts to the real environment and improves the accuracy of positioning.

This study aims to investigate how the relationship factors, including equity, shared responsibility and relationship dependence leverage the value co-creation. The research studies the value co-creation process in a business-to-business (B2B) context between suppliers and customers and provides empirical evidence of the underlying effects.

Using social exchange theory, the research uses a mixed-method of in-depth interviews and questionnaire surveys. The sample of the survey has 123 business customers.

The findings suggest that equity not only positively affects but also mediates the effect of shared responsibility on value co-creation. The mediation effect is further moderated by the relationship dependence that buyers have on the seller.

The cross-sectional survey used cannot establish causality relationships. Although the goal was not to establish causality, it could limit the rigor of the study. The longitudinal design could be used in the future to better address this deficiency. While the paper is the initial step to analyze the factors influencing value co-creation empirically, more studies could examine other commonly discussed constructs.

This empirical study enriches the value co-creation literature by examining the antecedents’ detailed mechanism that facilitates value co-creation in a B2B context.