Abstract:The quality of lathe bed has a great influence on the reliability of the complete machine, and reasonable evaluation can guide the improvement of process regulation. On the basis of quantitative evaluation of the bed's quality in thermal aging process, the concept of thermal aging entropy is proposed. The cause of lathe bed quality problem are analyzed in six aspects of 5M1E. By fuzzy comprehensive evaluation, the preliminary evaluation of the six aspects is obtained, and then the entropy assessment is combined with the Vague fuzzy evaluation to attain the comprehensive weights based on the six factors. Finally the integrated weighting factors and the preliminary evaluation are used for comprehensive evaluation of lathe bed quality.

Abstract:The analysis of failure properties of wind turbine blades is the important foundation for the stability and reliability analysis of the whole machine. By combining the finite element simulation with the full scale static load test, the deflection properties of the 100 kW medium sized experimental blade developed by IET, Chines Academy of Sciences under different load conditions are obtained. The study focuses on the failure properties of blades under large load conditions, and with the experimental data and finite element simulation results, the failure risk area and failure mechanism are analyzed. It is determined that the cause for fracture failure of the blade is the interlayer failure caused by the shear stress under heavy load and the consequential degradation of the resin material.

Abstract:To understand the movement behavior of wet magnetic particles in magnetic fluidized beds, the numerical simulations of wet magnetic particles movement under effect of uniform magnetic field are performed. In the mathematical model, the discrete element method (DEM) is adopted to simulate the particles movement, while both magnetic force and liquid bridge force models are considered. A two-dimensional dam-break problem is simulated to observe the effects of magnet-field and liquid bridge on the behavior of particles motion.Theresults show that:without magnet-field, as liquid-volume friction increasing, the speeds of particles become slowly and the particles are gathered obviously. When a magnet-field is applied, the particles form some chains parallel to the direction of magnetic sense, which reduce the average velocity and displacement of particles.

Abstract:Different loadings of WO₃/SBA-15 and WO₃-ZrO₂/SBA-15 are prepared by sol-gel method and characterized by XRD, BET, TEM. The activity of photodegradation of rhodamine B and the adsorption of ammonia ability are investigated. The results show that the rhodamine B is photodegraded easily by using W_x/SBA-15 (x=20,30,40,50) and W₄₀Zr_y/SBA-15 (y=3,5,7,9). Photocatalytic activity from high to low is W₄₀/SBA-15>W₅₀/SBA-15>W₃₀/SBA-15>W₂₀/SBA-15,while doped into ZrO₂,Photocatalytic activity from high to low become W₄₀Zr₅/SBA-15>W₄₀Zr_9/SBA-15>W₄₀Zr₇/SBA-15>W₄₀Zr₃/SBA-15. The rate of photodegradation with W₄₀/SBA-15 and W₄₀Zr₅/SBA-15 are 73.4% and 86.6% respectively. WO₃/SBA-15and WO₃-ZrO₂/SBA-15 also have good cycle efficiency and the advantage of reusability.

Abstract:The composition characteristics and formation mechanism are analyzed for magnesium-bearing inclusions in the steel by sampling and thermodynamic calculation. The results show the main oxides is MgS precipitating with 2MgO·SiO₂ or MgO-Al₂O₃-SiO₂. And MgS and AlN are the main precipitates. MgS-bearing compound oxide inclusions are mainly globular within 1 μm to 2 μm in size. MgS restricts MnS precipitation, and any type of MnS isn't found in the steel. MgS-bearing inclusions exist in the steel with three forms:MgS wrapped with spherical oxide core, MgS uniformly distributed on the surface of spherical oxides, and MgS orientedly precipitated on oxides matrix or with AlN. Thermodynamic calculation results indicate magnesium content and characteristics of oxides decide the composition of inclusions in the steel. MgS is easy to precipitate with MgO-Al₂O₃-SiO₂ complex with high MgO-bearing and sulphur capacity. The size of inclusions forming by MgS orienteering precipitating on oxides matrix or with AlN is much bigger, and their precipitation and growth method is related with the crystal structure of MgS and inclusions matrix. Fine MnS and MgO·Al₂O₃ can be diminished by controlling MgO content in refining slag to form composite inclusions bearing MgS.

Abstract:Based on fuzzy multi-class support vector machine, a method for detecting microblog spammers is designed. Firstly, a multi-class SVM(support vector machines) is used to construct multi-classifiers, and a training set is re-selected for each type of user's classifier. Then, the constructed training set is used to train the multi-classifier, and five user classifiers are obtained after repeated remediation. Finally, for the non-separable samples of multiple classifiers, fuzzy clustering is used to perform the fuzzy processing. An improved membership function is defined on the optimal classification plane perpendicular to the SVM, and the maximum membership degree is used to reclassify the samples. Experimental results show that this method can solve the problems of mixing and missing points in multi-classification under the premise of ensuring the detection effect of spammers.

Abstract:In order to reduce the iron loss and improve the dephosphorization efficiency of the converter for dephosphorization by the full triple stripping process, a model, based on the oxygen balance mechanism, is bulit to predict the end point FeO content and the Levenberg-Marquardt neural network algorithm is adopted in this model. The calculation of the oxide mass (FeO, CaO, SiO₂, MgO, MnO, P₂O₅, Al₂O₃) with the oxide balance mechanism model and the tapping temperature are used as inputs to the neural network toolbox to train the network with minimum error. The results show that the heat with relative error of 10% between the predicted value and the measured value of FeO is up to 85%.This proves that the FeO prediction hit rate of the model is high, and can provide theoretical basis for production on site.

Abstract:Scandium content of scandium concentrate in Western Sichuan is 189.80 g/t, and the main scandium-containing minerals are chlorite, montmorillonite, talc and amphibole. The contents of iron, calcium, magnesium are high, and the separation of scandium is difficult. Alkali fusion, hydrolysis, and hydrochloric acid leaching process are applied to the separation of scandium from scandium bearing concentrates in Western Sichuan. The results show that under technological conditions as roasting temperature is 650℃, roasting time 15 min, dosage of sodium bicarbonate 100%, dosage of hydrochloric acid 15%, leaching time 75 min, leaching temperature 45℃, and the liquid solid ratio 1.5:1, leaching rate of 99.56% is obtained. The chemical composition, morphology and energy spectrum analysis of leaching residue show that the main components of leaching residue are silicon, aluminum and magnesium, and scandium content is as low as 4.32 g/t. There is no obvious peak of Sc spectrum in SEM analysis of leaching residue, which indicats that most of scandium is dissolved into liquid phase, thus proving theoretically the effectiveness of alkali fusion-hydrolysis-hydrochloric acid leaching process.

Abstract:The optimization of ore drawing scheme is the basis of optimization control and intelligent management of ore drawing. In this paper, VC++ is used as a programming tool to optimize the single level ore drawing scheme. The main contents include:determine the elements of the ore drawing scheme and criteria for its optimization; construct a 3D model of drawing optimization to determine the ore drawing level and the ore drawing boundary; determine the structure parameters of the ore drawing and layout of drawpoint automatically, and establish a computational data search model of ore drawing and its slice grade, by the estimation of which to determine drawpoints and the grade distribution of slices; establish ore resource value model based on the profit of mine enterprise, with the market price, production cost and dilution index as basic input parameters to calculate the value and profit of each slice, so that to determine the best height of drawing, tonnage and cutoff grade of drawpoints under different technical and economic conditions. Based on the result of the above experiment, the optimization scheme of ore drawing is made, providing data related to ore drawing plan and management.

Abstract:In order to study the process and mechanism of coal and gas outbursts caused by dynamic loads in complex stress environment of deep mining condition, coal and gas outbursts simulation equipment under static and dynamic loads is developed based on the similar outbursts simulation devices proposed before. The test device is composed of a coal sample room, an outlet unit, a loading system and a measuring system used to investigate the properties of gas adsorption and desorption, seepage characteristics under the condition of static and dynamic loads. This experimental facility can be used to simulate the phenomenon of coal and gas outburst under the coupling action of static and dynamic loads. The results show that there is more liability of coal and gas outburst induced by non-gas desorption and non-coal pillar than that by gas desorption and coal pillar under a same impact load. And the outburst strength of non-coal pillar is bigger than that of coal pillar. According to the characteristics of the facility, a new formula of evaluating the outburst strength is proposed finally, which may provide a new way to estimate the energy range of coal and gas outburst in the future.

Abstract:In the Vanet application scenario, due to the high speed motion of the vehicle, the topology of the network keep changing, and most routing protocols need to maintain their neighbor table in time for routing select. Frequent retransmission of data caused by neighbor selection error will result in high time delay and unreliability. Many Vanet classic protocols cannot be applied to all scenarios. For this reason, this paper proposes a hybrid Vannet routing algorithm based on the highway application scenario NDK (Vanet Neighbor Discovery Method By Kalman Filter). The algorithm uses the GPSR (Greedy Perimeter Stateless Routing) idea of the classic geographic location routing algorithm, with the help of Kalman filter prediction model to predict the neighbor node table, and at the same time, the predicted values are periodically modified by roadside device (RSU, Road Side Unit). The result of NS-3 simulation experiments show that, compared with the classical GPSR algorithm and other algorithms based on time and motion, the algorithm has better packet arrival rate and lower transmission delay.

Abstract:To improve continuous supply ability of present pre-mixed abrasive water jet (AWJ) system, a new method is proposed to realize continuous feeding using the principle of jet pump suction and mixed abrasive. Entrainment of abrasive in pump mixing chamber is attributed to negative pressure field formed by ejection of a certain speed pressurized water from the jet pump nozzle. Abrasive mingled with water in chamber flows through throat pipe and diffusion pipe into high pressure hose, and transforms into required AWJ by acceleration of cutting nozzle. Based on analysis of structure and working principle, structure and size are designed for this continuous feeding system. Numerical simulation method is used to optimize the design of the area ratio of cutting nozzle and jet pump nozzle, which influences continuous feed and jet performance. Area ratio impact on system performance and optimal value range are analyzed and determined, respectively. System performance is verified by laboratory pressure test, continuous sand and cutting experiments. The result indicates that negative pressure and sufficient pressure gradient formed at abrasive inlet under suitable area ratio structure are beneficial for absorption and acceleration process, besides, the front of cutting nozzle still retain enough static pressure that can be converted into kinetic energy to facilitate efficient continuous operation of premixed abrasive water jet system.