Actual Application Process Research Articles

Nonlinear Dynamic Analysis of high speed multiple units Gear Transmission System with Wear Fault

Abstract. The helical gear system is an important form of transmission in high-speed trains, and helical gear failure has a great impact on the transmission performance. To investigate the influence of wear parameters on the nonlinear dynamics of gear systems, the wear fault parameters of a bending-torsion-shaft coupling mode with six degrees of freedom are established. Using the variable step fourth-order Runge-Kutta numerical integration method, the gear dynamics model with fault parameters is analyzed to get the dynamic response of the helical gear system. The system excitation frequency, evolution of system periodic motion, quasi-periodic motion, and chaotic motion with variable fault parameters are analyzed qualitatively based on the results, including the system status judgment criteria of phase plane graph, Poincaré cross-section graph, bifurcation diagram, and RMS. The results show that wear fault affects the system differently at different frequencies. Finally, the correctness of the conclusion is verified through experiments, and the impact on the actual application process is analyzed.

Properties of phase transition and interfaces of Cu2ZnSnS4 with hetero-phase junctions

Over the past few years, quaternary Cu2ZnSnS4 (CZTS) has attracted a great deal of attention as the most promising photovoltaic absorber layer, because it is composed of abundant and non-toxic elements. CZTS has two fundamental crystal structures under conventional preparation conditions: kesterite (KS) and stannite (ST). Because of the extremely similar crystal structure and the extremely small crystal binding energy, the phase transition between these two crystal structures is very easy to occur. Therefore, in the actual preparation and application process, it is very likely that there is a phase junction between KS and ST in CZTS material. In this article, based on density functional theory calculations, we first discussed the phase transition process caused by stress in details, which is one of the common phase transitions in experiments. The transition pressure exists at around 31 GPa and the phase transition is most likely to appear along the [100] crystal orientation. On this basis, we calculated and analyzed the structure and properties of five kinds of hetero-phase junctions which are composed of low index crystal planes and have very little interfacial stress. The hetero-phase junctions that composed by (101), (110), and (100) crystal planes present the type-II band alignment, which is beneficial for the photoelectric conversion. While, the hetero-phase junctions that composed by (112) and (001) crystal planes present the type-I band alignment, which offer larger energy barrier for the photo-generated carriers and is disadvantageous for improving photoelectric conversion. These findings can contribute to research on the relevant properties of CZTS absorber layer in the future.

Design of Picking Roller for Corn Harvester Picking Machine and Selection of Hydraulic Motor

In the actual application process, the corn harvester has problems such as high loss rate of fruit and energy waste. This article analyzes the corn picking device, the reason for the high loss rate is found, and a new picking roller is designed. Through the calculation of the force and torque of the picking roller and the chain during the harvesting process of the corn harvester, the power required for the picking device is obtained, and the hydraulic motor model required for the picking device is further obtained. Through design and analysis, we determined the optimum speed of picking roller in corn picking process: 836r/min, picking roll inclination angle: 35°, and picking roll radial size: 75mm. The article determines that the hydraulic motor model is the American white cycloidal motor WS80.

Effect of pressure, temperature, and mass fraction of CO2 on the state of the resin in crude oil

ABSTRACTThis paper focus on the main influence factors (temperature, pressure, and mass fraction of CO2) on the state of resin in the crude oil during CO2 flooding by using a visualization method. The state of resin is not affected by the variation of the temperature. Only when the pressure is increased to a certain value, the state of resin can be affected by the variation of the pressure. During the variation of the mass fraction of CO2, the state of the resin has a significant change, including the growth out of nothing, expansion from small to large, and transformation from a adsorbed solid to a flowable liquid. During the actual application process of CO2 flooding in oilfield, the influence of the temperature can be ignored, the appropriate mass fraction of CO2 is below 30% and the gas injection pressure should maintain a relatively low value. The results can provide a theoretical basis to avoid the resin aggregation during CO2 flooding.

Atmospheric channel model of maritime visible light communication based on repeated coding

Visible light communication (VLC) is a new type of wireless communication technology, and its applications in offshore ships and ship-shore lamp signal systems are drawing increasing attention as a supplement of communication net. In maritime environment, VLC system is affected by many factors, of which the wave fluctuation and atmospheric turbulence are the most noticeable. The turbulence will make signal intensity fluctuate randomly, and thus reducing the performance of VLC system operating in the atmosphere. To establish an effective VLC network in the actual marine environment, an effective channel transmission model needs to be established and used to study the performance of the maritime VLC link. Considering large aperture diameter receiver with the aperture averaging effect, log-normal distribution model is employed to deduce the mathematical expression of average bit error rate of maritime VLC system in atmospheric turbulence. By using time-diversity to transmit interleaved symbols with repeated coding in a maritime VLC system, it is possible to ensure that the code-word passes through multiple channels to resist the deep fade performance, and to reduce the bit error rate due to the occurrence of deep fading in a single channel. In the actual application process, in order to improve the system performance, the average signal-to-noise ratio usually increases with the transmission power increasing, but for a VLC system, there are some difficulties in making the high-power high-rate visible light transmitters. And the power will produce light pollution and even damage the naked eye. The implementation of the repetitive coding principle is simple, and in some special cases it is even better than the complex orthogonal space-time coding and other schemes, so studying the system performance of the repetitive coding scheme is of considerable value for practical application. Based on the modified Pierson-Moskowitz spectrum, the effect of wave height, transmission distance, atmospheric turbulence intensity, receiver aperture size and visibility on the average bit error rate of VLC system are analyzed. The performance of the VLC system between lighthouse and ship is affected by the fluctuations of the sea waves, and the average bit error rate changes with randomness and complexity like the sea waves in a short distance. As the wind speed increases, the marine environment becomes worse and the average bit error rate is undulate. The average bit error rate of maritime VLC increases with the increasing of transmission distance and atmospheric turbulence intensity, and with the decreasing of receiver aperture size, wavelength and average signal-to-noise ratio. Atmospheric turbulence intensity and visibility have a significant effect on the system performance, and it should be emphatically considered to take measures to reduce the influence. Increasing receiver aperture and repetitive coding are effective to a certain extent. In the present work a new model is proposed for evaluating the performance of a maritime VLC system and providing reference for practical application.

Fault Diagnosis Method of Cigarette Dust Collecting Centrifugal Fan Based on Set Empirical Mode Entropy

According to characteristics of the centrifugal fan fault signals, such as non-stationary, non-linear and sample scarcity during actual application process, a new method of ensemble empirical mode decomposition sample entropy and support vector machine fan fault diagnosis was proposed. In this method, the axial displacement signal is decomposed into a series of stable intrinsic mode functions by the EEMD algorithm firstly. Then, the phony mode components of the IMF are filtered and removed according to the correlation coefficient rule, and the entropy of the filtered IMF is calculate respectively and then be considered as the eigenvectors. Finally, the eigenvectors are put into the LIBSVM and BP neural network to carry out mode identification. At last, the feasibility, effectiveness and superiority of the above method are verified by experiments.

Static adsorption of protein-polysaccharide hybrids on hydrophilic modified membranes based on atomic layer deposition: Anti-fouling performance and mechanism insight

Initial membrane fouling affects fouling behavior and characteristic significantly. Static adsorption investigation contributes to intensively understand the initial fouling process. In order to determine the superior anti-fouling material prepared by atomic layer deposition, the TiO2, Al2O3 and ZnO modified membranes were successfully fabricated, characterized by XPS, XRD and SEM and then employed for static adsorption of BSA and SA foulants. More importantly, the anti-fouling mechanism was interpreted by adsorption isotherms and thermodynamics. Results showed that the adsorption amount of BSA and SA on PVDF membrane decreased by 43.2% and 73.0% with ZnO modification, reaching the highest among all the modified membranes. As a consequence, the minimum reduction of pure water flux and increase of membrane resistance were realized after fouling. The Sips model presented the most satisfactory fitting for BSA and SA adsorption on ZnO modified membrane. Thermodynamic investigation revealed that the ZnO modified membrane exhibited the lowest degree of spontaneity and the weakest interaction with foulants (London dispersion forces of physisorption). Moreover, the smallest ΔS value indicated the regular distribution of foulants on membrane surface, which greatly alleviated membrane fouling. The relatively smooth surface of ZnO modified membrane with lower roughness and water contact angle confirmed the excellent anti-fouling property. The reported results in this study could provide fundamental basis for the anti-fouling performance of ALD modified membranes, which would accelerate the actual application process.

Research on the Fault Diagnosis of Power Battery Based on Comprehensive Fuzzy Evaluation

In the actual application process, power battery may not behave properly, such as insufficient charging, internal resistance increment, capacity reduction and etc, the paper establishes a fuzzy comprehensive evaluation model of power battery to diagnose judge and analyze. The diagnostic results are given in the form of battery health status DOH and maintenance information. The paper tests the model through Actual working conditions of electric vehicle, and the results show that the actual fault information is consistent with the diagnostic results of model. The model is reasonable, and it can be used to diagnose the faults of power battery.

Building cognizance rule knowledge for fault diagnosis based on fuzzy rough sets1

With the continuous development of huge systems, dependence on the system is continually increasing. The failure of such systems will cause huge losses. The reason for system failure is often unclear, so that inconsistency and uncertainty between fault data will appear. In the actual application process, there is a process of change. If it is possible to predict the failure probability from the monitoring parameters, it will be very beneficial to system troubleshooting. Therefore, this paper proposes a new recognition algorithm based on fuzzy rough sets, in order to adapt to the processing of uncertain fault detection data. Additionally, the optimal direction of the dynamic information entropy increment is used to predict the fault information. This can quickly find the faults and provide important information for fault detection. It is verified that the proposed algorithm can improve the early warning and the accuracy of fault diagnosis information systems in the fault simulation analysis of a diesel engine.

Research on Reinforcement Layout Optimization of Bridge Foundation Bored Pile

In this paper, the poor applicability problem which the bridge foundation bored piles reinforcement design in the actual application process is not related to specifications is studied, and bored pile length calculation LP is optimized specifically, as well as, friction pile reinforcement design problems are also researched. Verified by examples show that the optimized reinforcement design fully meet engineering safety requirements, meanwhile, more economical.

A Study on the Quality Assessment System of Substructure Reinforcement Method

For substructure reinforcement method, corresponding quality assessment system is established based on analytic hierarchy process (AHP). At the same time, the actual application process of the system was found. Structure of judgment matrix, synthetic weight and for each layer of element and fuzzy comprehensive evaluation was figured out. Finally, the system is verified by practical engineering. Something is obvious as the result shows. Firstly, the comprehensive assessment system for reinforcement quality of bridges is reasonable and practical. Secondly, this system takes some advantages to the systematization, standardization and theorization for the assessment to reinforcement quality of bridges.

A Study on the Quality Assessment System of Reinforced Concrete-Skein Reinforcement Method to Arch Bridges

For reinforced concrete skein method to arch bridges, corresponding quality assessment system is established based on analytic hierarchy process (AHP). At the same time, the actual application process of the system was found. Structure of judging matrix, synthetic weight and for each layer of element and fuzzy comprehensive evaluation was figured out. Finally, the system is verified by practical engineering. Something is obvious as the result shows. Firstly, the comprehensive assessment system for reinforcement quality of bridges is reasonable and practical. Secondly, this system takes some advantages to the systematization, standardization and theorization for the assessment to reinforcement quality of bridges.

A Study on the Quality Assessment System of External Prestressing Reinforcement Technology

For external prestressing reinforcement technology, corresponding quality assessment system is established based on analytic hierarchy process (AHP). At the same time, the actual application process of the system was found. Structure of judgment matrix, synthetic weight and for each layer of element and fuzzy comprehensive evaluation was figured out. Finally, the system is verified by practical engineering. Something is obvious as the result shows. Firstly, the comprehensive assessment system for reinforcement quality of bridges is reasonable and practical. Secondly, this system takes some advantages to the systematization, standardization and theorization for the assessment to reinforcement quality of bridges.

1.06 μm InGaAs/InGaAsP量子阱半导体激光器的温度特性

The temperature characteristic of 1.06 μm InGaAs/InGaAsP quantum well laser diode was studied.The output optical power,threshold current,conversion efficiency and spectra of the module were measured and analyzed when the module was operated with different current at different temperature.The results show that the module's characteristic changes with the temperature in the range of 15 ℃ to 55 ℃.The module's CW output optical power reduced from 40.7 W to 29.4 W.The threshold current increased from 9.29 A to 17.24 A.The conversion efficiency reduced from 54.22% to 37.55%.The lasing wavelength shift is 0.37 nm/℃ and the characteristic temperature is 68.6 K.The temperature of the device in the actual application process should be controlled in the range of 15 ℃ to 25 ℃ to maintain the stability of the device performance.