In order to ensure shipboard medium voltage power system work successfully. In this paper, the existence of intermittent grounding fault of the shipboard power system is analyzed and studied. Meanwhile, A simulation model of shipboard medium voltage power system with multiple branches is built on MATLAB/SIMULINK,...

For the analysis of transient zero through the thyristor turn-off characteristics of recovery factors, the researchers are by changing the polarity of the supply voltage of the anode current commutation always realize thyristor is turned off, but will be under a lot of anti-off thyristor during recovery...

With the wide usage of electronic devices, harmonic wave is becoming worse. A method of Phase-Shifting Control of Double Pulse (PSCDP) is introduced in this paper. In continuous conduction mode, mathematical model between harmonic and phase-shifting is built, FFT is used to evaluate the harmonic content...

Dissimilar magnesium alloy AZ31 and pure copper sheets with a thickness of 5mm were successfully friction stir welded. Microstructure and mechanical properties of the butt joints were investigated. Complicated microstructure was formed in the nugget zone, in which vortex-like pattern and lamella structure...

This study is a factory waste paper pulping wastewater of Shandong Zibo as treatment object, with ozone generator homemade ozone water, hydrogen peroxide, activated carbon, aluminum sulfate, polyacrylamide, manganese dioxide co-processing, combined with flocculation and sedimentation, adsorption, filtration,...

This experiment explores to pre ozone used for wheat straw pulp hypochlorite bleaching wastewater treatment of optimum oxidation time, initial pH of Fenton reaction water, H2O2/FeSO4 dosing ratio, reaction time on Fenton method depth treatment effect of bleaching effluent. The bleaching wastewater is...

The circular bead of aero-engine fan shaft was obliquely shocked by laser shock processing (LSP). After oblique laser shocked, the residual stress and microstructure characteristic of fan shaft were investigated and analyzed. The rotary bending fatigue tests and fracture analysis were also conducted....

Pipeline transportation plays an important role in the resources deployment and economic development of our country. Its dimensional repair technique is an important guarantee to ensure the safety and reduce the loss. Tapping machine draws a lot of attention as the key equipment. According to project...

In this paper, an experimental investigation of wetting behaviors of water droplet on rough metal substrates is presented, in order to study the influence of rough structures on contact angles of metal substrates. The static contact angles and contact angles evolution over time are measured with a video...

The vibration isolators play an important role in the field of high resolution metrology and manufacturing, optical, physical and chemical experiments. Magnetic suspension vibration isolator (MSVI) is an efficient method to suppress the oscillations in vacuum environment. This paper firstly presents...

This design includes both the hardware system and software system. The control system can not only achieve the motion control but also can realize simulation. Hardware system is constituted by Parallel Robot Body, Embedded IPC (Industrial Personal Computer), servo drive and motor system, EtherCAT module...

A reliability adaptive modeling method for CNC Machine Tools based on kernel function is proposed. Choosing Gaussian distribution as the kernel function, the optimal model with least integral square error as the objective is established, and cross-validation method and traversal search method are used...

Grey prediction of CNC machine spindle system failure is modeled with GM(1,1) grey prediction as data accumulation weaken randomness and strengthen regularity. The model result provides preventative maintenance of CNC machine spindle system with theoretical foundation. The example analysis shows that...

The viscosity of sludge not only affects its transport properties, but also the drying efficiency. In the paper, the sludge property of apparent viscosity was studied with the different types of sludge moistureÿcontent ofÿsludge and temperature with the help of NDJ series digital viscometer. The results...

The precision control of cutting current is the important performance index of the plasma cutting power supply, so the study of plasma cutting current control strategy have great significance. This paper first summarizes the development situation of plasma cutting power supply, and the domestic plasma...

With the development of 3D modeling technology, the number of 3D models has been increasing and people have been paid more and more attention to the 3D model retrieval technology. This paper presents a CAD semantic model retrieval method based on design intent, which is based on the design intention...

With the increase of LNG power ship, the structure form of the fuel tank has been paid more attention. In this paper the advantages and disadvantages of LNG powered ship fuel tank with double shell tank structure or independent C type single shell tank structure are discussed from the initial evaporation...

We present a millimeter-scale, 3mg-weight electrostatic flapping-wing actuator which can generate lift force of 1.5mg under a stroke frequency of 80Hz, and makes the lift-to-weight ratio reach 0.5. As such, this work makes a key step in achieving electrostatic actuated FMAV's autonomous flight

In recent years, with the power grid and ultra-high voltage power transmission project increased, tension stringing is taking an important part in transmission project. Due to the shortcomings of traditional theoretical formulas, it is not precisely to reflect the dynamic tension of wires. In this paper,...

The forster resonance energy transfer (FRET) between different CdTe QDs and RhB were investigated by steady-state and femtosecond time-resolved photoluminescence spectra technique. Through the measurements on three different CdTe sample solutions, it was found that the FRET efficiency is proportional...

Water shortage is very serious in kunming area. Based on the precipitation and evaporation data of 2001-2011 of Kunming provided by Yunnan Meteorological Bureau, the article analyzes the change features of annual, seasonal and monthly rainfall and evaporation over the last 11 years. What's more, by referring...

With the refrigeration equipment working medium transition from high GWP to low, it is significant to study the environmental friendly refrigerant to protect the environment and avoid the greenhouse effect. Through theoretical analysis and experimental study of R32 and R1234ze mixtures, this paper provides...

The level set method is frequently used to simulate and capture the moving interface in the molten metal casting and forming field. However, the level set function has to be re-initialized after several time-steps. And influence of the smoothing parameter on numerical accuracy of the moving interface-capturing...

Atmospheric environment simulation in urban space plays an important role in the improvement of urban air problems and the sustainable development of the city. Using Remote Sensing (RS) and the spatial analysis technology in Geographic Information System (GIS), combined with the numerical simulation...

Current standards in the field of self-propelled machinery for forestry require equipping tractor cabins with roll-over protective structures (ROPS). It is necessary to reduce the risk of operator's injuries caused by tractor rollovers or falling trees. This study deals with the investigation of forest...

The trajectory accuracy of the carbon fiber 3D forming robots is one of the key factors to ensure the quality of forming. It is well known that carbon fiber 3D forming robots have high repeatability but low accuracy. Compared to conventionally used calibration methods, dual-PSD based methods provide...

This paper proposes a physical model of pressure compensation with accumulator based on the simulation research. The best accumulator can be chosen quickly and reasonably for different sampling systems. The mathematical model about the final pressure of the accumulator is established. The accumulator...

The 'Ptosis' is a phenomenon that eyelid droops and cannot lifts on normal level. If somebody has the ptosis, they use the frontalis muscle in forehead when the eyes open. In this paper, the frontalis muscle's EMG was measured about stare angle. People who have the ptosis were confirmed that they use...

The viscosity of paint dissolved liquid for enameled Wire is key that manufacture enameled wire, paint dissolved liquid is volatilization and change every moment, this paper presents a new method for real-time measurement of the viscosity of paint dissolved liquid for enameled wire, the new method is...

Heavy load palletizing robot in solving labor shortage, improve labor productivity, reduce production cost and the labor intensity of workers, improve the production environment, etc. It is of great significance. This article expounds the heavy load of palletizing robot working principle, structure and...

Shipping is an effective solution to the current flowing bulk goods. Because it deficiencies that the shipping demand scheme is determined by experience. It proposed building demand integer programming model based on task constraints, estimated shipping demand scheme. Firstly, determine the sensitivity...

Combined power plant has been the important development trend of ship power in the future. The dynamic characteristic of the power plant has made a great impact on stability, maneuverability and economy of the ship. So the research of dynamic Characteristic on the combined power plant has great significance...

Since natural gas is mainly transported or supplied in a liquefied state under high pressure, BOG (boil off gas) is frequently generated due to the adiabatic relation outside the pipe. To reduce BOG, various studies are being conducted. Recently, vacuum-insulated pipes are mainly used. Thus, in this...

The need for natural gases has recently been increasing for energy production and demand. Accordingly, many different studies are now being conducted on ways to supply liquefied natural gases (LNG) and on the valves that are used to supply those gases. Although there are various types of valves that...

First, we conduct the research on the mechanical mechanism of smoke control system to form a continuous water curtain and analysis the mechanical model of continuous water curtain and micro-unit; then simulate the continuous water curtain's shape of smoke prevention system by using Fluent software and...

Tri-generation systems are regarded as one of the most efficient technologies to save energy consumption and reduce carbon emission. In this research, a smart grid using renewable energy and energy storage unit is studied as the electrical part of a tri-generation system. This study aims at satisfying...