Abstract:On the basis of studying shield machine and planetary transmission, to address cutting drive system of shield machine, a novel dual drive planetary transmission system with large capacity is presented, and its principle and structure are analyzed. Through establishing a new kinematical model of the transmission system and analyzing its characteristics, the transmission ratio, rev and torque relationship and changing rules within the system are acquired. By comparing the simplified experimental results with theoretical results，it is shown that the variation is basically the same, which verifies the correctness of the model and analysis method. The high-power dual-driven planetary gear transmission system with great transmission ratio, strong carrying capacity, can perform the function of low-speed and high-torque output, and meet basic requirements of shield machine. It can not only replace the traditional multi-driven transmission system, but also achieve the transmission function in three different types of shield machine.

Abstract:To study the impact of coupling circuits in high speed motorized spindle’s dynamic mathematical model on load characteristics of the spindle, according to invariance principle of control theory, external decoupling branches is introduced into the point where the difference between reference current and feedback current of the high speed motorized spindle is, to eliminate the impact of coupling voltage, and then the impact way of excitation current changes and torque current changes on the spindle’s flux, electromagnetic torque, and load characteristics are studied when the load varies. Meanwhile, the load characteristics are tested on the test platform of high speed motorized spindle. Theoretical analysis and experimental results show that the decoupling effect of high speed motorized spindle directly affects the stability of the spindle’s flux and the linear tracking ability of the torque current on load, which is reflected by the parallelism of mechanical characteristic curve under different frequencies, the pulse level of electromagnetic torque, the load capacity of the spindle, power factor, efficiency and other parameters. Therefore the spindle’s actual decoupling results and dynamic performance under the control mode can be judged and forecasted, according to the trends of mechanical characteristic curve, power factor curve and efficiency curve.

Abstract:To compensate the thermal deformation error of NC(numerical control) gear hobbing machine tools and improve the accuracy of gear machining，based on the clustering regression analysis theory, temperature measurement points are optimized to compensate thermal error. Accordingly a thermal model is set up by using least squares theory, and experimental result shows that the model is very accurate. A thermal error differential helix compensation scheme is proposed，which adopts direct compensation outside completely and can achieve real-time compensation for thermal error independently. Compared with other compensation methods，this one is unlimited to the openness of NC system and has a great popularity.

Abstract:In order to research the offshore wind turbine which operates in harsh environment with transient and variable working conditions, the system is simulated and analyzed by simulation technology. The aerodynamic load of wind turbine is calculated by applying GDW theory and wave load is calculated by applying Airy wave theory. The drive chain is programmed in Matlab/ simulink and the flexible multi-body model of the wind turbine is built in Adams. The combined simulation of the wind turbine is carried out. The results of a 5 MW offshore wind turbine show that the method has excellent ability to simulate the performance almost the same as software Bladed result.

Abstract:With the linearization of the flow in oil chambers, the continuity equation of flow and the dynamic equation of the shaft are built for the hydrostatic journal bearing and thrust bearing respectively. Next, the transfer functions of the two bearings with capillary throttle are deduced. Then, the performance of the two bearings is simulated in Matlab. In general, the simulation results are well matched to the experimental data provided by Guangzhou Machine Tool Research Institute. It indicates that both of the models can predict the dynamic characteristic of the two bearings. Finally, the dynamics response of the hydrostatic thrust bearing is studied in various rotational speed of the shaft. Also, the dynamic performances of journal bearing are simulated in changing of inlet pressure and thickness of oil film.

Abstract:The profile error correction of spiral bevel gears is difficult. To solve this problem, the inspected method of spiral bevel gears tooth surface is studied in 3906 gear measuring center. The grids of tooth surface is measured by measurement software. Taking reference tooth surface as the goal, a method of machine setting reverse using approximation algorithms is proposed, and a mathematical model is build. At last, a reverse example based on grinded spiral gear is given. The result shows that the cutting machine setting of bevel gear tooth surface can be exactly calculated.

Abstract:There is no effective integration between knowledge management and process management in current modern workshop management. In order to deal with the problem and optimize business process operation, a knowledge management operation mode for manufacturing process of workshop is proposed on the basis of analyzing knowledge management requirement, and the operation mode is analyzed in detail from four aspects, manufacturing business, knowledge resource, knowledge operation and relevant information systems. Some key technologies to realize the operation mode are studied, including semantic description of manufacturing process and knowledge representation based on ontology technology. Finally, a case study is provided and the feasibility and effectiveness of the operation mode are demonstrated.

Abstract:The tensile strength, yield strength and elongation of AZ31 magnesium alloys on different annealed conditions are tested by mechanical properties experiments. A model of corresponding mechanical properties is built by applying artificial neural network, and it is optimized by a new method，namely all permutations and combinations training of parameters. The results show that the network model has an excellent performance, which is based on optimal parameters obtained from all permutations and combinations training. Compared with traditional model, whose parameters are obtained from conventional heuristic, the improved model has higher average correlation coefficient and lower average error. Therefore, it can predict the mechanical properties of AZ31 magnesium alloy on different annealed conditions more accurately.

Abstract:Effects of Nd content on the microstructure and mechanical properties of Mg-5.0Y-xNd-0.6Zr（x=0,1.0,1.8,2.6,3.4,4.2，mass fraction/%）alloy casts are investigated by optical microscopy(OM), scanning electron microscopy(SEM), differential scanning calorimetry(DSC), X-ray diffractometry(XRD) and tensile tests. The results reveal that increasing Nd content can refine the average grain size of alloys from 33.5 μm to 19.2 μm, reduce the number of Y atom in α-Mg and Mg24Y5 grain dispersed in the matrix, and increase β phase with the distribution of discontinuous network in crystal boundary. With the increase of Nd content, the tensile strength keeps rising first and subsequently falling, and the yield strength has a sharp increase at first and then gradually becomes constant, with the maximum values of 214.5 MPa and 102.8 MPa, respectively. The elongation and section shrinkage linearly decrease from 16.4% and 23.8% to 4.9% and 2.7% with the increase of Nd content. The mechanism of grain size refinement of Mg-5.0Y-xNd-0.6Zr alloys can be explained by Nd and Y enrichment in the forefront of solid-liquid interface during solidification process which enhances the supercooling of the solute rich zone and inhibits the crystal grain growth.

Abstract:AJ61-xNd magnesium alloys are prepared in vacuum furnace under the protection of argon atmosphere and the effect of Nd content on microstructure of the test alloy is studied. The corrosion behavior of AJ61-xNd alloys in 3.5% NaCl aqueous solution is investigated by static weight-loss test and polarization curve measurement. The results indicate that with the addition of Nd, binary Al2Nd phase and Al3Nd phase are formed in the alloy, meanwhile, grain sizes are greatly reduced with the addition of Nd and the refinement effect on the test alloy is the best when the mass fraction of Nd is 0.5%. It is found that due to the addition of Nd, the corrosion rate and corrosion current of AJ61 magnesium alloy can be significantly reduced, the equilibrium potential and corrosion potential of the test alloy can be enhanced substantially. The corrosion resistance of AJ61 magnesium alloys is improved a lot with the Nd addition. The AJ61-0.5Nd magnesium alloy has the best corrosion resistance behavior.

Abstract:The rheological property of high titanium slag is a main factor to influence the vanadium titanomagnetite smelting in blast furnace. It plays a great role in discharging slag, separating iron and slag and even the life of blast furnace hearth. The acrylonitrile-butadiene-styrene multipolymer(ABS) dense suspension is taken to simulate the system of high titanium slag. Apparent viscosity is measured by a NXS-11A rotating cylinder viscometer. The impact of temperature, volume fraction and particle sizes on the suspension apparent viscosity is studied. The results show that temperature and volume fraction have a strong influence on the suspension apparent viscosity, while the particle size has a weak effect. The suspension shows Bingham behavior within a wide concentration range. The dependence of the appear viscosity on temperature and amount of solid addition can be described by a binary function equation.

Abstract:The influence of trumpet-shaped ladle shroud and straight ladle shroud on characteristics of fluid flow in a single strand slab tundish under different liquid levels through physical simulation is studied. The results show that the peak value of RTD curves after using trumpet-shaped ladle shroud is relatively low， the curves become smooth， the flow field is relatively stable and there isn’t short circuit flow. Also, the respond residence time, the mean residence time and the plug residence time of the liquid in tundish are prolonged. Besides, when the trumpet-shaped ladle shroud is used, the dead volume fraction is smaller， the plug volume fraction becomes larger and the ratio of the plug volume fraction to the dead volume fraction is greater. Therefore, when the liquid level of tundish is going up, its flow pattern becomes more reasonable after using trumpet-shaped ladle shroud, which is in favor of improving the quality of molten steel in tundish.

Abstract:Using precise design principle, a multi-objective programming mathematical model of the BOF-Caster matched is established for single production line in the steelmaking plant of all plate and strip, according to the segmentation of steel grade and product specification of product mix. Objectives of the model have less investment, less difference between production capacity of the converter and continuous caster, higher operating rate of converter and higher level of weighted average casting speed. The model is solved by the improved delaminating sequence method. Then, the overall configuration method of BOF-continuous casting in the steelmaking plant is proposed through integrating single production lines. According to the production outline of a new large steel plant, the result of the model shows that the configuration scheme of the steelmaking workshop of the steel plant is a better design scheme.

Abstract:In metallurgical dusts treating by RHF (rotary hearth furnace) direct reduction, processes of Zn, K, Na removal and flue gas formation have significantly influence on RHF process. Direct reduction experiment on cold bonded briquettes, made by mixing metallurgical zinc-bearing dusts with proper proportions, are investigated in a high temperature tube furnace simulated RHF. Ingredients, microstructures and phase compositions of flue gas and secondary dust are collected and analyzed. The results show that removal rates of Zn, K, Na and Pb are 98%, 80%, 88% and 85% respectively, gas ingredient of flue gas of N2, CO, CO2 are 71.4%，14.5% and 14.1% respectively, and phase compositions of secondary dust are ZnO, KCl, Zn5(OH)8Cl2H2O, PbO and NaCl. Studies show that ZnO content of secondary dust is up to 80%, which can be reused as secondary zinc resource. Then mechanism of removal of Zn, Pb, K and Na and forming of flue gas are analyzed in direct reduction process.

Abstract:Dynamic aperture control technology is one of the most important parts in ultrasonic imaging system. Excellent control technology of dynamic aperture can effectively improve the quality of ultrasonic imaging. Based on deep analysis of ultrasonic beam distribution, a control method for dynamic aperture which can eliminate the scanning dead zone of focused beam is presented. The detection region is even divided according to the number of probe array elements. The desired focused beam width is calculated between the next two scan lines at different depths, and then according to the beam width, the required aperture size for different depths is determined. The method is not affected by the probe parameters or detection objects, and it can be widely employed in ultrasonic imaging system. The simulation experiments indicate that the proposed method can effectively improve the whole quality of ultrasonic imaging.

Abstract:Motion estimation is the most complex part in H.264. Intra prediction is an important part of motion estimation. There are a number of intra prediction modes in H.264, which no doubt greatly increase encoding complexity. In intra prediction, the way of choosing prediction method is rate distortion optimization or using correlation properties. For complexity problem, the paper provides an improved intra prediction mode selection algorithm. This algorithm uses a new detection method to detect the pixel correlation in the direction of mode selection. Test results show that the algorithm has reduced the computational complexity and increased the encoding speed highly in the premise of ensuring video quality.

Abstract:Based on the investigation of energy consumption and air conditioning system working of 14 typical hotel buildings in Three Gorges Reservoir area cities, energy consumption characteristics of hotel buildings are analyzed. Then the use status of energy efficiency technologies of those hotel buildings is analyzed. Finally, effective energy conservation approaches for hotel buildings are brought forward and the energy-efficiency potential of variable water volume system is analyzed through testing.

Abstract:To study the process of personnel evacuation at light railway stations, make the personnel evacuation plan and optimize the architectural design, the simulation model and program of personnel evacuation are improved. The stair is treated as a separate space unit and a residual value is used to gather the advantages of grid model and the continuity of occupant’s movement. Through questionnaire surveys and field observations at elevated light railway stations in Chongqing, the passengers’ personal parameters and the response characteristics to fire are obtained. The tested movement speed of people agrees to the empirical data. The process of personnel evacuation and the location of each person at any time are demonstrated dynamically by using the computer-programming Zone Grid Evacuation Simulation Software (ZGESS) on the platform of MATLAB. Meanwhile, the total evacuation time is calculated by the program, and it is the same with the data of observation approximately.

Abstract:For the open-loop surface water source heat pump systems, energy consumption of water supply is the key factor for energy saving of system. On the basis of energy consumption model of heat pump unit and energy consumption model of water supply etc., open-loop surface water source heat pump system energy efficiency ratio coupling model is established. Based on energy efficiency ratio,the coupling limit value of surface water source heat pump system in different temperature of water supply and different energy consumption of water supply is obtained.Through the actual case, energy saving rate of the system is calculated in different temperatures of water supply and different system modes. And the determination method of the limit energy consumption of water supply of open-loop surface water source heatpump systems is established.

Abstract:Based on life cycle theory and the energy consumption status of energy embodied phase, embodied carbon emission coefficient is proposed to quantify embodied carbon emission of energy carriers. With the data of China’s statistical yearbook and relevant references, embodied carbon emission coefficients of selected energy carriers in 2005—2007 are obtained. For coal and oil products, the coefficients are 1.04~1.08. And 1.4 and 3.1 are for natural gas and thermal power, respectively. Analyzing the energy consumption of selected cement products, clinker production and coal consumption are the main carbon emission sources in terms of phases and energy carriers, respectively. From the analysis of the carbon emission in cement production, it is found that the emission amount of PI525 and PO425 are about 50% and 35% higher than that of PS325. And with the calculation, the CO2 emission amount is about 295.4~445.6 kg/t for the selected cement products.

Abstract:Novel 2-amino-4-(4-methoxyphenyl)-6-(piperidin-1-yl)pyridine-3,5-dicarbonitrile is synthesized using malononitrile, 4-methoxybenzaldehyde and piperidine as starting material in methanol by one-spot. The yield is 40% with three-component reaction at room temperature. The structure is confirmed by 1H NMR, MS and X-ray single crystal diffraction.

Abstract:In slope engineering, the shear resistance of rock and soil can never be exerted themselves by general pre-reinforced structure, through the coupling mechanism between reinforced structure and slope, an initiative decompression pre-reinforced structure consists of soft stuffing and pre-reinforced structure is presented. The setting and thickness of soft stuffing are both key questions during the design of initiative decompression pre-reinforced structure. On one hand, the setting of soft stuffing assure that parts of initiative decompression pre-reinforced structure cannot interact each other under reinforcing; on the other hand, the thickness of soft stuffing can assure that the shear resistance of rock and soil can be exerted by themselves, the sliding thrust which is endured by pre-reinforced structure alone is changed to be endured by soil and pre-reinforced structure together. Then the sliding thrust endured by pre-reinforced structure minimizes, accordingly the effect of initiative decompression is achieved. In the end, the calculation procedure of thickness is illustrated by a practical project and the result is rational.

Abstract:Based on the analysis of construction characteristics of manual digging pile in karst region, a scientific, timely and dynamic safety assessment system is the established and fuzzy AHP(analytic hierarchy process)is used to conduct a comprehensive safety assessment. The results are accordant with the actual situation and the construction practice has proved that fuzzy AHP is feasible to evaluate manual digging pile construction safety and good results can be achieved.

Abstract:On the base of traditional robust statics optimal design, by considering time parameter, dealing with uncertain parameters with perturbation finite element, and using Newmark method for dynamic analysis, robust optimal design is applied to dynamic response optimization. Compared with the traditional optimal design’s result in a frame system, robust optimal design of the frame displayed a significant improvement in performance.