Aiming at the hysteresis nonlinearity of the piezoelectric driven systems for tunable external cavity diode lasers, a modelling and control method was proposed herein based on Rayleigh-BP model. Firstly, a Rayleigh-BP rate-dependent hysteresis model was developed by spatial expansion method, which achieved an accurate prediction of rate-dependent hysteresis nonlinearity of piezoelectric driven systems. Secondly, the inverse model of Rayleigh model was solved by an inverse algorithm, and the model was combined with a BP neural network to design a feedforward controller to compensate the systems. Finally, the feedforward control method was validated by simulation and experiments. The results show that the Rayleigh-BP model developed has high accuracy, the root mean square error is only as 0.0469 μm at 10 Hz. The feedforward control method may significantly improve the linearity of the system outputs, the root mean square error of the simulation results is as 0.0274 μm and the linear correlation coefficient R2 is as 0.999 92 at 40 Hz. The experimental results show a root mean square error of 0.0506 μm and a linear correlation coefficient R2 of 0.999 55 at 30 Hz, which greatly reduces the hysteresis phenomenon.

To study the compressive mechanics properties of pillar centered cubic lattice with different reinforcement directions and their filling structures, silicone rubber filled lattice structure test specimens were prepared herein. The compressive mechanics properties of two lattice structures(BCC1 or BCC2, loading direction was either the same or perpendicular to the direction of pillar rod in body centered cubic lattice with pillars) filled with silicone rubber were studied through experimental and simulation methods. The equivalent elastic modulus and compressive platform stress of two lattice structures were conducted using Timoshenko beam theory and ultimate load method. The results indicate that the proposed theoretical model may effectively predict the equivalent elastic modulus and compressive platform stress of two type lattice structures. After filling, the compression strength and energy absorption performance of the two lattice structures are enhanced, while the enhancement effect of the BCC2 structure is more significant. For the BCC1 lattice, rubber filling enhances the bearing capacity of the internal members. However, for the BCC2 lattice structure, rubber filling reduces the bending deformation of the members near the V-shaped shear band. As the radius of the lattice structure increases, the energy absorption coupling factors of both lattice structures first increase and then decrease, yet the energy absorption coupling factor of BCC1 type structure changes more significantly.

Nickel-based self-lubricating rare earth composite coating was prepared on the surface of 35CrMo steel by high-frequency induction cladding technology, and it was subjected to solution treatment at different temperatures. The effects of solution treatment at different temperatures on the microstructure, microhardness and wear resistance of the coating were studied by means of optical microscope(OM), scanning electron microscopy(SEM), X-ray diffraction(XRD), Vickers microhardness tester and friction and wear testing machine. The results show that after solution treatment, the elements diffuse fully, the dendritic form gradually becomes single, and the microstructure at the interface mostly changes from columnar dendritic to cellular dendritic. After solution treatment at 850℃, the main phases of the composite coating are γ-(Ni, Fe), Cr(Fe-Ni-Cr), Ni₃Fe, TiC, Cr₂₃C₆ and CrB phases, the average microhardness is the highest, reaching 867.7 HV0.2, the friction coefficient and wear amount are relatively small, which are reduced by 17.21% and 21.66% respectively compared to the coating before solution treatment, and the relative wear resistance is relatively high, which is 2.46.

Thermal barrier coatings (TBCs) are widely used in the hot-section components of gas-turbine engines to allow operation at higher temperatures (＞ 1 200 ℃), which has created some new issues. One issue is the spallation and premature failure of TBCs caused by calcium-magnesium-alumino-silicate (CMAS) deposits, which arise from entry of siliceous debris such as fly ash, sand, dust, and volcanic ash into engines. Since 1953, over 130 jet aircraft have encountered volcanic ash clouds, with varying degrees of damage and endangering the lives of many passengers. The 2010 eruption of Eyjafjallaj?kull volcano in Iceland led to the most severe air-traffic disruption since World War II. The operational response produced economic losses approaching 1.7 billion. When these debris enter the hot-section airfoil, they melt and are accelerated from low speed (~15 m / s) to near supersonic speed (~300 m / s), impacting and adhering to the TBC surface. Even with only a few molten silicate ash droplets adhering to the surface of hot-section airfoils, an initial deposit layer can form and large melt pockets (several cubic centimeters in volume) can accumulate. Such deposits can 1) block cooling holes and air flow paths, and 2) react with the top coating of hot-section airfoils. Furthermore, adhering droplets infiltrate the interior of TBCs under capillary forces. Due to the thermal gradient and thermal cycling, the infiltrated CMAS solidifies and fills in the microcracks, pores, and grain boundaries, resulting in loss of strain tolerance and increased coating stiffness. For traditional 7–8 wt.% yttria-stabilized zirconia (YSZ) material, chemical reaction with CMAS destroys the phase and structure stability. YSZ grains dissolve and Y-depleted ZrO₂ grains precipitate due to the relatively low solubility of Zr⁴⁺ compared with Y³⁺ in melted CMAS. Upon cooling, the newly formed grains transform from tetragonal (t) to monoclinic (m) phases, accompanied by a 3%–4% volume expansion. As turbine inlet temperatures improve and industry production grows, TBCs are suffering from severe CMAS corrosion. This issue limits further application and development of TBCs; enhancing anti-corrosion performance of TBCs has become a concern. Herein, we compare the room-temperature and high-temperature properties of different CMAS and study the failure mechanism of TBCs exposed to CMAS. We also determine the most effective CMAS protection method. The results show that the chemical compositions, especially the Ca:Si ratio, of CMAS such as volcanic ash, dust and sand are different, further affecting their high-temperature viscosities and melting behaviors. With infiltration of molten CMAS toward the coating interior, chemical reaction occurs between them, resulting in instability of the coating microstructure and properties, and failure. Significant methods including inert-layer, rare-earth doping and novel materials have been proposed to improve the CMAS corrosion resistance of TBCs. The research and future development directions of CMAS corrosion and protection are proposed, providing a reference for design of novel TBCs.

 Due to the immaturity of intelligent technology in universality， robustness and security， intelligent interactive products were prone to “behavior conflict” due to the mismatch with user behavior patterns in intention expression， information processing， decision logic， interaction timing and action intensity. Unified modeling and optimization of multi domain behavior processes of human-machine environmental systems were the key to realize behavior characteristic regulation and forward design of intelligent interactive products. This paper systematically reviewed the research progresses of multi domain behavior process representation model， modeling language and tool， model validation and behavior process optimization of human-machine environmental systems from four dimensions：how to represent， what to represent， how to verify and how to optimize. The existing problems and limitations in this field were analyzed， and the future research focus and development trend were prospected. 

There were two forces that promoted the development of gear measurement technology. One was the continuous new requirements for gear measurement put forward by industrial development, and the other was the penetration of continuously improving related technologies in the field of gear measurement. Since the 21st century, the convergence of these two forces promoted the rapid development of gear measurement technology. Based on a brief review of the evolution of gear accuracy theory and gear measurement technology in the 20th century, the basic framework of gear generalized accuracy theory was put forward. The gear measurement technology during the last 20 years was systematically summarized from the aspects of gear full-information measurement technology, in-site rapid gear sorting and detection technology, extreme measurement technology for extra-large gears and micro gears, high-precision gear artifacts and traceability, etc. There is more than 100 years since the beginning of gear precision measurement, and it is currently in the critical stage of the transition from the 3rd generation to the next-generation of gear measurement. The overall technical concept of next-generation of gear measurement was presented, the basic theory and key technical problems that must be overcome were listed for realizing the next-generation of gear measurement, and the research focus and scientific issues of gear measurement in the next 10 years were prospected.

Many factors affected surface roughness. Unique properties of brittle materials made the surface formation mechanism of brittle materials more complex, which made the machining quality difficult to control. By constructing the model of surface roughness, the surface roughness was predicted, and the machining quality might be controlled. In order to better reference the previous research results, characterization parameters of surface roughness were summarized herein. The methods used to establish the surface roughness model were constructed. The main research schools of the model and their development history, main academic contributions, and characteristics of the model were analyzed and summarized in detail. Finally, the future research direction of surface roughness model construction was prospected.

A six-axis serial robot error calibration method  was proposed based on the robot geometric parameter errors and the base frame position and attitude errors. Firstly， an geometric parameter error model of the IRB6700 robot was established based on the MD-H method， and the mapping relationship between the geometric parameter errors of the robot connecting rods and the end pose errors of the robot was obtained. Then， the position and attitude errors of the base frame were further considered， and the robot error model  was established considering the errors of the base frame. In addition， to address the cumbersome operation and large accidental errors of traditional calibration methods， an improved parameter identification method was proposed to further improve the operability and calibration accuracy of the calibration processes. Finally， the body calibration experiments and the base frame error disturbance experiments were carried out. The results show that the proposed method decreases the average position error of the robot from 3.1928 mm to 0.1756 mm， and the standard deviation of the position errors decreases from 0.5494 mm to 0.0830 mm. Moreover， the consistency of the parameter identification results under base frame error disturbance is higher than 99%， and the calibration accuracy and stability are improved. 

In order to reduce the welding heat input of low carbon steel and optimize the welding deformation and other defects, the triple-wire indirect arc welding (TW-GIA welding) method was used, and the heat transfer mechanism of TW-GIA was discussed based on the infrared temperature measurement system and high-speed imaging measurement results. The results show that TW-GIA welding has a significant advantage of small heat input, and can realize single-pass welding without obvious welding deformation. The width of the heat affected zone was smaller than that of MIG welding. Unlike traditional arc welding, the heat input of TW-GIA welding gradually decrease with the increase of welding height. Heat transfer mode changed from arc heat convection + molten pool heat conduction to only molten pool heat conduction when the welding height increased from 4 mm to 24 mm. The grain size of TW-GIA fusion zone and heat affect zone was small, and the widmannstatten structure was eliminated. The average microhardness of TW-GIA weld zone reached 289.8 HV, the maximum tensile strength was 472 MPa, and the elongation was 26.5%.

Under the action of welding thermal cyclic load, the internal peritectic structure of austenitic stainless steel weld is coarse columnar crystal, and its orientation is anisotropic in different areas of the weld. The nondestructive testing of austenitic stainless steel welds is conducted using method of ultrasonic array for the ultrasonic scattering caused by coarse columnar crystals and the sound beam deflection caused by different grain orientations. A signal analysis method based on decomposition of the time-reversal operator is developed for noise reduction processing of ultrasound full matrix data. Using ray tracing method, the ultrasonic wave propagation path determination method in anisotropic media was investigated and applied to the correction of beam deflection for ultrasonic array total focus imaging of austenitic stainless steel welds. Nondestructive testing of austenitic stainless steel welds was conducted using ultrasonic array, and the results showed that the time-reversal operator-based decomposition method was effective for the suppression of scattering noise in the detection signal and highlight the echoes from defects, which can improve the signal-to-noise ratio of full-focus imaging by 10 dB, moreover the beam deflection correction can improve the accuracy of defect localization in total focus imaging of ultrasonic arrays.

Thermal-mechanical simulation of direct energy deposition (DED) is an effective method to predict the residual stress and deformation and optimize deposition process parameters. The simulation accuracy depends on input parameters which are difficult to be directly and accurately measured in most cases. This paper, taking heat source parameters as examples, proposes an inverse identification method based on support vector machine and genetic algorithm, and the inversely-identified heat parameters are further used to improve the thermal-mechanical model accuracy of real DED applications. Firstly, simulation errors of simple single-track deposition models under different heat source parameters are obtained. Secondly, the relationship between the heat source parameters and simulation errors is established using support vector regression, and the optimized initial heat sources are identified using genetic algorithm. Thirdly, a forward-inverse closed loop is applied to narrow the ranges of heat source parameters for more precise parameter identification. Finally, a thermal-mechanical model for a turbine blade using the optimal parameters is constructed to further verify the proposed method. The results show that the optimal heat source parameters extracted from single-track deposition models can be extended to accurately predict the thermal and mechanical results of a turbine blade DED case, which provide a practical method for DED process optimization (e.g. distortion compensation) in industry applications.

MQL technology had the advantages of low cutting fluid consumption and high lubrication efficiency. However, there were more problems such as inadequate lubrication and low cooling performance under the specific conditions. MQL synergistic technology, such as cryogenic air or liquid carbon dioxide et.al. which combines the advantages of cooling and lubrication, might effectively solve the machining problems of difficult-to-cut materials. The latest research of principle, key devices and technology applications of various types of MQL synergistic technology were summarized. The performance of various devices and their parameter regulation characteristics were analyzed in details. Combining with the applications and the mechanism of MQL synergistic technology, the machinability in titanium alloy, nickel alloy, stainless steel and other difficult-to-cutting materials were analyzed. In addition, a sustainable analysis of various types of MQL synergistic technology was provided. The purpose is to provide technical support and reference for the engineering applications of clean cutting technologies.

The stealth performance of warship was an important performance and tactical index. Passive control technologies such as vibration absorption and isolation were widely used in the fields of vibration and noise reduction， but they still might not meet the needs of acoustic stealth of ships. Therefore， it was of great significance to study active vibration and noise control of the ships. The active spectral reshaping control might change the characteristics of radiated noises to acoustic stealth the ship. The connotation of spectrum reshaping active control was introduced, and three aspects of adaptive inverse control， adaptive active control and adaptive spectrum reshaping active control were summarized according to the development of adaptive spectrum reshaping active control theory. Finally， the effectiveness of the algorithm was verified by the applications in the field of naval ships. 

 For the automatic detection of weld defects in large storage tanks, a wall-climbing robot needed to complete automatic omni-directional scanning. Firstly, according to the force state of the wall-climbing robot under different operating conditions, a mechanics model of the wall-climbing robot was established to analyze and obtain the four unstable hazards of non-sliding, non-longitudinal rollover, non-lateral rollover and compound motion state. The force state of the permanent magnet adsorption wheel was simulated and optimized by Maxwell software to meet the adsorption requirements. At the same time, the coding wheel with auxiliary adsorption function was designed to supplement the margin of safe adsorption force while feeding back the position information to increase the obstacle crossing and anti-instability abilities. Finally, according to the design model, the wall-climbing robot body was manufactured and tested. The test results prove that the robot designed herein may realize the omnidirectional driving operations with load stability at various ustable hazards.

Due to the large amount of silicon particles，the machinability of the high-volume fraction silicon aluminum alloys was poor.Severe tool wear and deteriorated machined surfaces with defects were major problems in cutting high-volume fraction silicon aluminum materials.To further explore the machining damages，the milling experiments of 70% Si/Al（mass fraction is 70%）alloy were carried out，where the tools were prepared by chemical vapor deposition（CVD）method.Milling force，tool wear and mechanism of machining damages were investigated.As a comparison，milling tools with TiN coating were also utilized under identical cutting parameters.The results show that the main tool wear modes of the diamond coated tools are coating peeling and abrasive wear，which are due to the impact and scratching of hard silicon particles in milling processes.In the normal wear stages of the diamond coated tools，the milling force is stable in the range of 4357～4895 N，while the milling force of TiN coated tools is higher and the tool life is shorter.The damages on machined surfaces are mainly pits，scratches and ruptured particle.Under the premise of ensuring the strength of cutting-edge radius，machining damage may be obviously reduced by reducing the radius of tool cutting-edge.The surface roughness value（Sa=23 μm）machined with a cutting-edge radius of 12 μm is lower than that with a radius of 156 μm（Sa=67 μm）.

Micro-area induction heating(MIH), as a localized heating technique with characteristics of non-contact, controllable, and fast thermal-response, was shown numerous potentials in microsystems, such as microelectromechanical systems and microfluidic chips. The fundamentals of MIH were introduced herein, and the research progresses of MIH in the fields of packaging, driving, material growth, et al， was presented systematically. Furthermore, some existing technique problems needed to be solved were analyzed, and several prospective research directions of MIH were pointed out.

Aiming at the driven bevel gear fracture failure of a certain type of aero-engine central drive bevel gear due to traveling wave resonance in actual processes, combination of simulation analysis and test verification was used to study the traveling wave resonance characteristics and influence laws of spiral bevel gears under parameter adjustment. The modal analysis of the driven gears was carried out based on finite element method, and the relationship between the thickness of the spoke plate and the working temperature with the gear traveling wave resonance characteristics was discussed. Transient dynamic analysis of meshing gears was carried out based on Hertz contact theory, and the influences of load power, operating temperature and damping factor on the stress distribution of driven bevel gears under traveling wave resonance were discussed. The comparison of simulation and test results shows that the errors of simulation results of modal calculation and dynamic analysis are within a reasonable range. Under the premise of meeting the relevant requirements of gear design, the resonance speed or resonance frequency may be avoided by adjusting the thickness of the spoke plate. In terms of the sensitivity of the resonance parameters of the vibration stress distribution, the analysis shows that when the gear is working in the third or fourth nodal diameter traveling wave resonance states, the stress values at the tooth roots are the largest, and the stress values on the front surfaces of the spoke plate are the smallest; when the temperature and damping factor changing, the change of stress values at front of the driven bevel gear spoke plate is small, and the change of stress values at the back of the spoke plate and tooth root is big. Therefore, in improvement and optimization designs of the gears, it is necessary to deal with the third or fourth nodal diameter traveling wave resonance.

In order to study the effects of active speed modulation on the internal flow field and blood damages in the blood pumps, the CFD method was adopted to simulate the full flowpath internal flow of a blood pump under speed modulations. The combined numerical simulation of the lumped cardiovascular system mathematical model and the rotary blood pump model was used to obtain the ventricular and aortic pressures under the assisting of the blood pump, which were then set as the inlet and outlet boundary conditions of the blood pump in CFD simulations. The flow fields of blood pump under the constant speed and three types of asynchronous speed modulation waveforms, including sine, square and triangle waves, were analyzed, and the velocity distribution and shear stress distribution of the rotary blood pumps were obtained. The results show that the flow pulsation of blood pump is enhanced under speed modulations, which is a feasible scheme to restore the pulsation of the blood flow. Among the three speed modulation waveforms, the blood pump flow pulsation index is high and the shear stress in the blood pump is small under the sinusoidal speed modulation, which is a relatively ideal speed modulation waveform.

The revolutionary history of composite preforms forming technique was summarized from the standpoints of manufacturing technology and equipment development.The technical characteristics of the composite preform forming manufacturing technology were analyzed.The status of typical technology and equipment of composite preform forming manufacturing at home and abroad as well as existing challenges and gaps were listed.Finally，the future development directions and trends of composite preform forming technique were discussed prospectively.The development of digital precision forming manufacturing technology and equipment for high-performance composite components may promote the technical progresses of composites in China better，and achieve more extensive promotions and applications.

 For turbine disk slots of high-end power equipment such as aero engines and gas turbines， the machining technologies were analyzed from two aspects of mechanical machining （e.g.， broaching， milling， grinding） and nontraditional machining （e.g.， wire electric discharge machining and wire electrochemical machining）， respectively. The development current situations were systematically explained from the viewpoints of design and application of tools， evaluation and control of machining quality. The important achievements of the research work in this field at home and abroad were also introduced. Finally， the development trends were generalized prospectively.

Prognostics and Health Management (PHM), including monitoring, diagnosis, prognosis, and health management, occupies an increasingly important position in reducing costly breakdowns and avoiding catastrophic accidents in modern industry. With the development of artificial intelligence (AI), especially deep learning (DL) approaches, the application of AI-enabled methods to monitor, diagnose and predict potential equipment malfunctions has gone through tremendous progress with verified success in both academia and industry. However, there is still a gap to cover monitoring, diagnosis, and prognosis based on AI-enabled methods, simultaneously, and the importance of an open source community, including open source datasets and codes, has not been fully emphasized. To fill this gap, this paper provides a systematic overview of the current development, common technologies, open source datasets, codes, and challenges of AI-enabled PHM methods from three aspects of monitoring, diagnosis, and prognosis.

COVID-19 pandemic has accelerated the re-shaping of globalized manufacturing industry. Achieving a high level of resilience is thereby a recognized, essential ability of future manufacturing systems with the advances in smart manufacturing and Industry 4.0. In this work, a conceptual framework for resilient manufacturing strategy enabled by Industrial Internet is proposed. It is elaborated as a four-phase, closed-loop process that centered on proactive industry assessment. Key enabling technologies for the proposed framework are outlined in data acquisition and management, big data analysis, intelligent services, and others. Industrial Internet-enabled implementations in China in response to COVID-19 have then been reviewed and discussed from 3Rsa€? perspective, i.e. manufacturer capacity Recovery, supply chain Resilience and emergency Response. It is suggested that an industry-specific and comprehensive selection coordinated with the guiding policy and supporting regulations should be performed at the national, at least regional level.