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A high-precision gyroscope is an important tool for accurate positioning, and the amplitude stability and frequency tracking ability of the drive control system are important and necessary conditions to ensure the precision of micro-electro-mechanical systems (MEMS) gyroscopes. To improve the precision of MEMS gyroscopes, this paper proposes a method to improve the amplitude stability and frequency tracking ability of a drive control system.

A frequency tracking loop and an amplitude control loop are proposed to improve the frequency tracking ability and amplitude stability of the drive control system for a MEMS gyroscopes. The frequency tracking loop mainly includes a phase detector, a frequency detector and a loop filter. And, the amplitude control loop mainly includes an amplitude detector, a low-pass filter and an amplitude control module. The simulation studies on the frequency tracking loop, amplitude control loop and drive control system composed of these two loops are implemented. The corresponding digital drive control algorithm is realized by the Verilog hardware description language, which is downloaded to the application-specific integrated circuits (ASIC) platform to verify the performances of the proposed method.

The simulation experiments in Matlab/Simulink and tests on the ASIC platform verify that the designed drive control system can keep the amplitude stable and track the driving frequency in real time with high precision.

This study shows a way to design and realize a drive control system for MEMS gyroscopes to improve their tracking ability. It is helpful for improving the precision of MEMS gyroscopes.

This paper aims to analyze the impact of the degree of local government decision-making competition on the optimal investment amount, investment location and investment failure of innovative investment enterprise under multiple risk appetite type of innovative investment enterprise. This paper also points out three regulation paths that central government could use to avoid the influence of local government decision-making competition on the validity of enterprise innovation investment (EII).

Based on analysis frame of government competition about unitary government states, this paper builds duopoly decision model to analyze influence of local government decision-making competition on EII. Considering information asymmetry and multiple risk appetite type of decision-maker, this paper analyzes influence of local government decision-making competition on location selection, the optimal investment amount, identification of investment failure and exit mechanism of EII according to different relationship between reference points of local government decision-making competition and EII.

The optimal investment amount of EII has positive correlation with risk appetite type of decision-maker, local government decision-making competition. Identification of investment failure and exit are divided into three phases. The boundary conditions are directly related to risk appetite type and amount of local government subsidy. Regional factor endowment and degree of preferential policy are main factors attracting enterprise investment. Local governments should analyze the interests of EII. There are three paths to avoid vicious competition among local governments: unified planning, revising of audit index, increasing penalties for failure of policies.

With rapid development of China's new urbanization process, urban economy has become an important carrier of economic development. Attracting foreign direct investment is an important measure to promote urban economic growth, and EII is the most important one. However new urbanization would lead to local government decision-making competition and then influence EII. Through analyzing influence of local government decision-making competition on EII, theory guidance could be provided to decision makers of innovation investment.

Blockchain, in general, diversifies supply chain management in record-keeping and maintains authenticity. In addition, traditional issues and challenges like overflow and information overload press down mysteriously whenever the blockchain steering wheel of the supply chain turns. Factually, the miracle and twists in supply chain resilience have not been incorporated under systematic review homogeneously. As a result, this study reviews the potential impact of blockchain on logistics and supply chain (LSC) efficiency. The methodology of this study provides a subjective assessment of the utility of blockchain-based LSC performance.

On the other hand, the review reveals new insights on its current acceptance and applications, with a particular emphasis on the Limit Redundancy Mechanism and Core Information-based Direct Comparison. Prospectively, the identified facts under the research paradigm and extensive literature survey will subsidize the practices of blockchain technology and possible areas of extension in supply chain resilience in luminous fashion in the future. After all, this study materializes new solid magnitudes, adaptability, and a realistic overview of blockchain-based LSC movements.

Failures in both followership and leadership become inevitable as mega construction projects are directed and controlled by toxic leaders. Consequently, team member's desire for knowledge hoarding silence is triggered and goal alignment between the leader and team members suddenly fades away to realize success in mega projects. Considering the growing importance of these rarely examined constructs and fragmented literature on toxic leadership (TL), team silence and mega project success (PS) in the global construction industry, the present study aimed to examine the effects of TL and project team member's silence (PTMS) on the success of mega construction projects. Moreover, the mediating influence of PTMS to link TL and mega construction PS has also been explored.

Drawing on survey data of 326 project professionals directly associated with mega construction projects worth US$62bn under the China–Pakistan Economic Corridor (CPEC), the conceptual model was tested with covariance-based structural equation modeling (CB-SEM) using Mplus program. Scales were adapted from previous research to measure TL (with its five-dimensions including abusive supervision, authoritarian leadership, self-promotion, narcissism and unpredictability), PS (with its three-dimensions including project management success, project ownership success and project investment success) and project team members' silence. Reflective–formative second order assessments were specifically applied to measure the multi-dimensional nature of TL and PS, respectively.

Mplus estimations revealed that TL negatively influences PS, besides forcing a culture of silence among project team members. Interestingly, the relationship between TL and PS is also negatively mediated by the PTMS.

The present study's findings are derived from data of project professionals (N = 326) to examine success in megaprojects under the CPEC. Hence, these findings may be re-validated through future studies on similar megaprojects (e.g. China's Belt and Road Initiative (BRI) worth US$8tn) that may also be predicated by TL tendencies, silent cultures and high-stakes involved to seize PS.

Policymakers, construction practitioners and other key stakeholders (e.g. departmental heads/supervisors) can take advantage of this new evidence to better interpret the success paradox in mega projects, and to reduce the spread and long-term damage of TL on team members and eventually create opportunities for PS.

The present study's novelty is manifested within this first empirical evidence on TL that breeds team silence in underperforming mega projects. Notably, present study offers alarming evidence on mega projects that can be easily derailed from success, as they continue to suffer from team silence and TL.

This study aims to optimize the preparation conditions and modify the nanofiltration (NF) membranes to prepare high-performance polysulfone/sulfonated polysulfone composite nanofiltration (PSF/SPSF-NF) membranes through interfacial polymerization.

Investigating the impacts of anhydrous piperazine (PIP) concentration, trimesoyl chloride (TMC) concentration and basement membrane type on NF membrane performance, the optimal membrane was prepared. In addition, nano-SiO₂ was added to the active separation layer to modify the NF membranes.

The comprehensive performance of PSF/SPSF-NF membranes was optimized when the concentration of PIP was 0.75 Wt.% and the concentration of TMC was 0.15 Wt.%, at which time the water flux was 66.1 L·m⁻²·h⁻¹ and the retention rate of Na₂SO₄ was 98.1%. The comprehensive performance of polysulfone/sulfonated polysulfone-SiO₂ nanofiltration (PSF/SPSF-SiO₂-NF) membranes was optimized when the blending ratio of nano-SiO₂ to PIP was 2:3, with a pure water flux of 81.9 L·m⁻²·h⁻¹ and a Na₂SO₄ retention rate of 95.9%. Compared to polysulfone nanofiltration (PSF-NF) membranes and PSF/SPSF-NF membranes, NF membranes with nano-SiO₂ increased the flux recovery rate by 22.9% and 8.7%.

PSF/SPSF-SiO2-NF membrane exhibits excellent antifouling properties.

There is currently no literature available on the preparation of NF membranes using polysulfone/sulfonated polysulfone (PSF/SPFS) as a substrate. This provides a method for modifying NF membranes, starting with the modification of the basement membrane and then modifying the active separation layer.

The rapid development of digital technologies drives digital entrepreneurs to pivot, a behavior that allows entrepreneurs to adjust original opportunities and explore new opportunities. This study aims to investigate the effect of the structural characteristics of digital entrepreneurial teams, the functional heterogeneity, on pivoting from the perspective of digital agility. Moreover, this study also examines the moderating effect of knowledge sharing.

Two-phase survey data were sourced from Chinese digital entrepreneurial teams through the entrepreneurial networks of MBA programs of a Chinese business school and entrepreneurial support organizations in China. The sample of 272 teams with 708 entrepreneurs was collected to test the hypotheses.

The functional heterogeneity of digital entrepreneurial teams, including industry background heterogeneity and occupational experience heterogeneity, positively impacts pivoting by providing heterogeneous knowledge and resources. Moreover, this relationship is mediated by the digital agility of the digital team, and knowledge sharing moderates the relationship between functional heterogeneity and digital agility.

While existing studies have mainly focused on the external factors, this study empirically investigates the team-level internal factors of digital pivoting in digital entrepreneurial teams, enriching the research perspective of pivoting. Moreover, the current study bridges the literature on digital agility with pivoting, broadening the theoretical mechanism of pivoting and expanding the theoretical boundaries of digital agility.

This study aims to improve the control accuracy and antidisturbance performance of the manipulator with the flexible link, a combined controller, which combines the novel backstepping sliding mode controller based on the extended state observer (ESO) and super-twisting sliding mode controller.

First, the dynamic of the system is constructed by Lagrange method and assumed mode method, and then the dynamic is decoupled by the singular perturbation theory to obtain the slow-varying subsystem and fast-varying subsystem. For the slow-varying subsystem, the novel backstepping sliding mode controller based on ESO is used to achieve joint tracking. For the fast-varying subsystem, the super-twisting sliding mode controller is used for vibration suppression. At the same time, to suppress chattering, the tanh function is used to replace the sign function in the reaching law.

The simulation results show that the combined control has better trajectory tracking performance, antiinterference performance and vibration suppression performance than traditional sliding mode control (SMC).

A novel backstepping sliding mode controller based on ESO is designed to guarantee the performance of the tracking trajectory. The new controller improves the converge rate. A super-twisting sliding mode controller, which can stabilize the fast-varying subsystem, is used to suppress the vibration of flexible link.

While previous studies find innovation to be an essential driver of export growth, the existing literature has neglected the role of different dimensions of technological innovation in export performance, especially in emerging countries. In particular, much less attention has been provided to investigate how enhancing innovation activities in more technical industries influence the relationship between technological innovation and export. Purpose of this paper is to present a unified framework to empirically investigate the integrated impact of the various technological innovation dimensions on export performance of industrial enterprises in China.

Using a panel dataset of enterprise-level data classified into China’s two-digit capital- and technology-intensive manufacturing industries for the 1998–2016 period and applying system-GMM regressions to control for the problem of endogeneity, the authors empirically investigate the integrated impact of a variety of the dimensions of technological innovation on export.

The authors find that: (1) Domestic R&D efforts and technology spillovers from foreign investment are critical determinants for capital- and technology-intensive exports. (2) External technology may not automatically contribute to export success whereas the interaction of external technology with domestic skill and expertise is a necessary condition for global competitiveness. (3) There exists complementarity between domestic and foreign innovation efforts when they jointly determine export. (4) Chinese government’s trade and innovation policies have significantly contributed to its export growth. Also, the authors examine that the extent of the effect of innovation on export depends upon the type of industry and it is found to be greater in capital- and technology-intensive industries.

This paper fills the research gap in existing literature by distinguishing between different dimensions of technological innovation and integrating them into a unified framework to empirically investigate their impact on export performance of industrial enterprises in emerging countries. The study provides important insights for policymakers.

The purpose of this paper is to present an analytical calculation for estimating the leakages field distribution in surface-mounted permanent magnet synchronous motors (SMPMSMs) according to a sub-domain field model for eccentricity fault detection.

The magnetic field domain is classified into four sub-domains of PMs, air gap, stator core and outer region. In the proposed method, the governing equations taking the rotor eccentricity effect into account per region and the interface boundary conditions between sub-domains are formulated using the regular perturbation technique, Taylor series and Fourier series expansion. Maxwell's equations are solved in different regions in the polar coordinate system regarding the boundary conditions.

The radial and tangential components of electromagnetic field distribution in all sub-domains of one SMPMSM are obtained using the proposed method analytically. Finite element analysis is used to validate the results of the proposed method; the results indicated that the analytical model matches the finite-element prediction up to 30% eccentricity, except for some peak values that depend on the harmonic order value. The results of this paper demonstrated that in the event of eccentricity, an asymmetric magnetic field is generated in the outer region of the machine. Although its amplitude is small, it can be an indicator for detecting eccentricity faults from the outside environment of the machine.

The formulas presented in this paper can be applied as a new technique for detecting eccentricity faults in these motors from the outside environment.