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In this work, 1200 V SiC JMOS devices with different Wsch (2 μm, 2.5 μm and 3 μm) are fabricated. The single unclamped inductive switching (UIS) tests under different Vgs_off (-5 V and 0 V) are carried out to investigate the avalanche capability. The avalanche robustness among various Wsch under same Vgs_off is also compared and analyzed by simulation. The different failure mechanisms between different Vgs_off are studied by failure analysis and simulation. The method of improving avalanche ruggedness of JMOS is proposed.

Erosive wear of working part is an usual damage mode of mechanized equipment in engineering, which is caused by multiple particle impacts with different impact angles and velocities. A test system for plastic metal materials subjected to multi-particle erosion is designed and manufactured. Based on the test system, trial samples of plastic metal materials suffered to multiple particle impacts can be produced via an air ejector, while images of corresponding damage surface can be observed with electron microscope. Erosion experiments of the twice particle erosions in succession were carried out through the experimental system with two different impact angles, i.e. 90° and 30°, and at a fixed impact velocity of 120 m/s. From the experiment results, it can be expected that the experimental system is suitable to laboratory tests of multi-particle erosion for plastic metal materials with reference to practical conditions in engineering.

During efforts to solve common technical challenges to the comprehensive recovery of rare precious metals associated with copper smelting, Xiangguang Copper (XG) independently developed a new process to treat anode slime using technology that captures precious metal using bismuth. This paper focuses on the introduction and application of this technology for capturing precious metals with bismuth. It also discusses silver electrolysis at high current density and bismuth recovery from precious metals slag. The new process shows good adaptability of raw materials, elimination of lead pollution, low energy consumption, environmental protection and high comprehensive recovery rate of metals, which promotes the technological progress of comprehensive recovery and utilization of associated resources in copper smelting process.

We reported the structural, magnetic and magenetocaloric properties of Mn1.25Fe0.75P0. 50Si0.50Bx(x = 0.01, 0.02 and 0.04) X-ray diffraction patterns show that all compounds crystallize in the hexagonal Fe2P-type crystal structure. Lattice parameter a increases while c decreases with increasing B contents. The Curie temperature of the compounds have been determined, the values are 219, 268 and 323.2 K for x = 0.01, 0.02, 0.04, respectively. The maximum magnetic entropy changes in a field change of 0~1.5 T are 6.1, 5.3 and 3.5J/kg·K for x = 0.01, 0.02 and 0.04, respectively.

Significant improvement of compatibility in PET/PA6 blends is essential to obtain fibers having enough mechanical strength as well as the comprehensive performance. In this article, copoly (ester-amide 6) was used as compatibilizer to improve the compatibility of PET and PA6. Three copoly (ester-amide 6) s with 5, 10% content of PA6 were prepared by co-polymerization from PTA , EG, as well as PA6 or caprolactam (A6), i.e. polyamide was incorporated both in the form of polymer and monomer, respectively. The sequence length of PET in the copoly (ester-amide 6) s is 33.4, 16.5 and 38.4 for PET-PA6-5%, PET-PA6-10% and PET-A6-5%, respectively, calculated by 13C NMR. Then PET/PA6 blend fibers were fabricated by melting spinning of PET and PA6 with 20 %wt addition of PET-PA6-5%, PET-PA6-10% and PET-A6-5%, respectively, to explore the effect of copoly (ester-amide 6) s on compatibility of PET/PA6 blend fibers, where the mass ratio of PET and PA6 is 85/15. DSC results show that the crystallization peaks of PET and PA6 during cooling from the blend melt become adjacent each other with increasing addition of copoly (ester-amide 6) s, even forming fused crystallization of them. It was found from SEM that the size of PA6 phase decreased and the phase boundary became indistinct due to the presence of copoly (ester-amide 6) s. Further more, the glass transition temperatures (Tg) of PET and PA6 closed to each other based on DMA result. Among these three copoly (ester-amide 6) s, PET-A6-5% display the best effect on the compatibility of PET and PA6 blend fiber, suggesting copoly (ester-amide 6) s could play important role in raise the compatibility of PET and PA6 blend.

We have investigated the effect of diluting treatment of poly (3,4-ethylenedioxythiophen e):poly (styrene sulfonate)(PEDOT:PSS) solution on the PEDOT:PSS films and the organic polymer solar cells based on poly [4,8-bis (5-(2-ethylhexyl) thiophen-2-yl) benzo [1,2-b;4,5-b0] dithiophene-co-3-fluorothieno [3,4-b] thiophene-2-carboxylate](PTB7-Th):[6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) using PEDOT:PSS polymer as the hole transport layer. The diluted PEDOT:PSS solution by water with 1:1.5 volume ratio was used to fabricate the hole transport layer in the organic solar cell, the fill factor and the shunt resistance of the solar cell can be significantly enhanced compared with the control cell, up to 64% and 949.03Ω·cm2, respectively.

In order which aim to save land resource and use low grade nature resource to realize high cost performance product. In this paper, the molding method of quartz sand fired brick is discussed. As the plastic (hand pressing) is only used to manually beat the mud mass, the sludge is squeezed by hand. Into the mold and molding and cold isostatic pressure molding pressure of 100 MPa, The difference is far away, which makes the gaps between the particles close to each other greatly different, the pressure of hand-press molding is small, the voids in the blank after molding are large and the hole diameter is large, and the green compact density of the brick body is small. The compact densities of the 65MPa and 150MPa pressed brick bodies are all lower than 100MPa, but 150MPa is still denser than 65MPa. The compressive strength is first increased and then decreased with increasing the molding pressure, when the pressure is 100 MPa, the maximum compressive strength is achieved at 100 MPa achieves the highest point.

This work investigated the effects of molar ratio of salt to alkali on the properties of tin oxide nanofilms to provide reference for optimizing its photoelectric conversion efficiency. The tin oxide film grown by hydrothermal method exhibited poor film-forming property. The macroscopic analysis revealed the formation of a thick film. The bonding force to the FTO substrate was poor, its brittle, and easy to fall off. When the molar ratio of salt to alkali was 1:8, the tin oxide film exhibited improved microstructure and large specific surface area, which could benefit electron transport. Moreover, the film showed excellent photoelectric conversion performance. However, mechanical properties, such as adhesion between the tin oxide film and the conductive glass FTO, remain to be improved.

Alumina ceramics with good mechanical and corrosion resistance are the ones of the most widely used engineering ceramics. The aluminum has high strength, high conductivity and high plasticity etc. so that aluminum ceramics are used in more and more industries. In this paper, the mass fraction of 25% Al2O3 powder and the mass fraction of 75% Al powder were mixed in the blender. Mixer speed is100r/min with mixing time of 3.5 h. Forming, sintering and a series of processes for preparing the alumina/aluminum metallic ceramic materials, through performance testing and analysis, found that the density of the sample firstly increased and then decreased with the increase of sintering temperature. A melting point is close to the sintering temperature and the density of the cermet can be made relatively high. When the sintering temperature is about 600°C and 700°C, the macro performance of sample is better. The cermet is sintered at 700°C and its microstructure is relatively better.

The Al2O3/Al cermet composite powders were prepared via the ball milling method,which provide raw materials for preparing high performance cermet materials. The results show that the number of Al2O3 particles on the surface of Al particles increases first and then decreases with increasing the ball milling time and milling rotating speed. The number of Al2O3 particles on the surface of Al particles increases with increasing ball to powder mass ratio. The analysis of the ratio of performance to price shows that the better parameters for preparing the pinned Al2O3/Al cermet composite powders are as follows, the ball milling time 24h,the ball milling rotating speed 100 r/min and the ratio of ball to powder 1:2.

A high-performance quartz sand insulation brick was prepared by using low grade quartz sand under different sintering process conditions. The optimum sintering process conditions were obtained by analyzing the relationship between microstructure and sintering process. Through the compounding, pulping, forming, drying and sintering processes, and the performance test of the porous brick, the following conclusions can be drawn, the comprehensive performance in all aspects, the porosity is similar, the preferred high compressive strength conditions, in order to get a best The bonding point, brick body sintering temperature of 1150 °C, porosity of 74.56%, compressive strength of 2.1 MPa of porous brick, and the pores are smooth, more uniform distribution. With the prolonging of the holding time, the porosity of the porous brick is reduced, and the performance is 1h, the porosity is 77.22% and the compressive strength is 2.05 MPa. When the raw material ratio is 60% quartz sand, 30wt% kaolin, calcium carbonate 9.6wt%, foaming agent 0.4wt%, water ratio 0.9 holding time at 1h sintering at 1150°C can get better porosity and compressive strength of the insulation brick. The porous material was sintered at 1150 °C, the content of foaming agent was 0.2wt%, the ratio of water to material was 0.9, and the compressive pressure and porosity were the better.

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

YAG has many excellent features and therefore has a wide range of applications. Preparation and properties of YAG porous ceramics via the casting method is investigated. Through analysis and discussion, the following conclusions can be obtained. With the increase of the content of foaming agent, in the foaming process of the slurry, bubbles generated by the foaming agent and water are gradually increased, the more pores are left in the body after casting, and when the blowing agent is too much, excessive bubbles are generated, which can lead to a very low strength of the green body and can not be formed and operated later. As the ratio of water to material increases, the porosity of the porous material increases. This is because when the blowing agent is constant, the amount of water required for foaming is constant, and the amount of foam generated is also constant. When the content of foaming agent and the ratio of water to material is both 1, the porosity and compressive strength is better.

Power consumption has long been a great obstacle in phase change memory technology. Silicon carbide was introduced to be a buffer layer between the phase change material and the metal electrode in this work. The results showed that the new structure mitigated the energy consumption and maintained the advantage of high speed. This is attributed to the thin SiC buffer layer that helps confine the generated Joule heat inside the active phase change volume and form more conducting paths by the high efficiency of the heat utilization. Additionally, another key role — inhibition of the material separation, is conducive to achieving stable and sustainable electrical operations.

The wetting behavior of SiC by molten Al and Al-Mg alloys using the sessile-drop testing equipment was investigated. The results showed that Mg has a remarkable influence on the wettability and reaction in the Al/SiC system. The contact angle between SiC substrate and molten Al-Mg alloys decreased more quickly with increasing of Mg content. The transition temperature from non-wetting to wetting dropped with increasing of Mg content, suggesting that the addition of Mg does promote the wettability of SiC by molten Al. The role of the Mg addition on the wetting was presumably attributed to its deoxidation as well as the inhibition of the interfacial reaction between Al and SiC.

Mullite matrix composites with laminated and stitched carbon fiber cloth preform as reinforcement were fabricated via the route of “infiltration-drying-heat treatment” using Al2O3-SiO2 sol as raw materials. Thermal properties from room temperature to 1673K of the composites were investigated. The coefficient of thermal expansion (CTE) increases first and then decreases, and reaches a maximum of 4.83×10-6K-1 at 1273K. As a result of the further sintering of matrix, the CTE is negative at above 1300°C. The specific heat capacity increases to the maximum of 1.547J·g-1·K-1 at 1473K and remains stable at above 1473K, with a minimum of 0.756J·g-1·K-1 at room temperature. The thermal diffusivity decreases from 1.1mm2·s-1 at room temperature to 0.707 mm2·s-1 at 973K as the temperature was elevated, and remains stable at above 973K. On the contrary, the thermal conductivity is improved with increasing temperature on the whole and varies from 1.859W·m-1·K-1 at room temperature to 2.325W·m-1·K-1 at 1473K.

Visible light responsive CoTiO3 nanoparticles with average diameter of 100 nm were successfully synthesized by sol-gel method and were firstly applied to catalytic activation of peroxymonosulfate (PMS) for degradation of organic pollutants (Rhodamine B (RhB)). Photocatalytic experiments illustrated that CoTiO3 nanoparticles reveal good photocatalytic activity and excellent ability to activate PMS, the synergistic effect of visible light photocatalysis and sulfate radical generated from activated PMS can degradate RhB efficiently. Besides, CoTiO3 nanoparticles maintain their high photocatalytic and activation efficiency after three times recycling.

Accurate material data shared in product lifecycle is the basis of manufacturing industry informationization. But material coding rule is usually different in enterprises. The code rule definition model based on code segment unit was proposed, and the segment unit was divided into four types as flow, selection, input and conversion according to code generating way. The concept of code segment structure tree was proposed to support the code method’s adaptability. The E-R model of adaptable coding system was described. The integration model of coding system, CAD, CAPP, PDM and ERP was put forward. Based on the model, generating code before design, generating code after design and generating code offline modes were proposed. Taking a specific material code rule in an enterprise as an example, the coding system’s application method was studied. The example shows that the proposed coding method is adaptable and effective.

In our previous work, silver nanoparticles (AgNPs) with ultrasmall sizes (4.3 ± 0.7 nm) can be in-situ obtained within the poly (vinyl alcohol) (PVA) fibers by mediating the electro-spun conditions. The obtained AgNPs “trapped” within the electro-spun PVA nanofibers were believed to be stable in the dry state, as the abundant PVA molecules could protect the dispersed AgNPs from agglomerating with each other. In this study, based on former study, aging tests about the nanohybrid mats were performed. Through ATR-FTIR spectra analysis, the formation mechanism of AgNPs within the PVA nanofiber by one-step electro-spun was confirmed. Atomic Absorption Spectroscopy analysis of the as-prepared PVA-Ag samples was performed in 14 h and the release of Ag+ was believed to be the main cause of its bactericidal effects. Scanning electron microscopy and transmission electron microscopy were used to characterize the nanofibers with AgNPs. After 4-month storage, the size of AgNPs doped in the PVA nanofiber became twice larger and the content of AgNPs was almost doubled.

By using Zr6.5(Sb2Te3)93.5 film, Te nanowires with a diameter of 5 to 30 nm were fabricated through annealing process. The results of the bright field TEM images, selected area electron diffraction (SAED) and high resolution transmission electron microscopy (HRTEM) demonstrated that the nanowire fitted well with Te hexagonal Te (P3121) structure. The EDS mapping implies that Zr element bonded with Te element and induced the formation of single crystalline Te nanowire during the annealing process.

The performance of phase change memory (PCM) cell, based on Ti0.5Sb2Te3, was significantly improved by using a tantalum dioxide buffer layer. The presence of a buffer layer reduced the reset voltage of the PCM cell. The theoretical thermal simulation and calculation for the reset process were conducted to analyze the thermal effect of the titanium dioxide heating layer. The improved performance of the PCM cell with dioxide clad layer can be attributed to the fact that the buffer layer not only acted as heating layer but also efficiently reduced the cell dissipated power.

Ag/AgCl electrodes as an important sensor are used in modern clinical detection and biomedical measurement, which have been widely applied in electrocardiograph (ECG), electroencephalogram (EEG), electromyography (EMG), electricity impedance technology (EIT) and so on. In this study, the electrode pairs were gel-to-gel connected. After a stimulating current, the alternating current (AC) or the direct current (DC), was injected through the electrode pair, the electrical potential was recorded, then impedance data of Ag/AgCl electrode was obtained. The results showed that the AC impedance of electrode increased, and then gradually decreased with the increase of current size. It was found that the DC impedance data of Ag/AgCl electrode was changed greatly after the electrode pair was injected into the alternating current. With the long time continuous measurement, the AC impedance of electrode pair gradually increased within the 12 hours. However, the significant fluctuations of AC impedance were observed after 12 hours. Comparing with the AC impedance, the DC impedance of electrode pair exhibited a great increase with the increase of measurement time.

When designing the servo valve with different structure parameters, the influence of the interaction between the liquid and the solid on the performance of servo valve can only be obtain by the method of experiment, and then it can increase the time and cost of designing the servo valve. The liquid-solid couple method can obtain the influence of structure parameters on the performance of servo valve under the circumstance of reducing the experimental cost and time. The paper chooses the servo valve of A and B as models for study, The text adopts FSI method to analyze the flow field of double nozzle baffle electro-hydraulic servo valve prestage through the software of ANSYS, research the change of the prestage flow field by deflection of loaded armature baffle components, contrast and analyze the change of velocity, pressure, power loss and flow coefficient of fixed choke, nozzle, return port, and the displacement of the valve core of slide valve, stress of armature baffle components, pressure at both ends of spool. Summarize the advantages and disadvantages of A and B servo valve, and find different parameters of servo valve have different performance, it is difficult to find a common structure and size. It can help us to select the requirement structure by using fluid-structure interaction, reduce experiments and save cost.

In order to efficiently fabricate dense three-dimensional carbon fiber reinforced mullite matrix composites (3D C/mullite), two kinds of Al2O3-SiO2sols with high solid content were used as raw materials. The ceramic yield and mullitization behavior of the sols and the densification process were investigated. It is indicated that the two sols have proper solid content and ceramic yield and can be completely transformed into mullite at 1573K, which make them be able to prepare composites. 3D C/mullite composites with a porosity of ∼25% were prepared by repeating less than 20 cycles of infiltration-drying-heating of sols, and the microstructures and mechanical properties were examined. The results suggest that the sol with smaller particle size derived composites exhibit well-sintered dense matrix and physically stronger interfacial bonding, which are beneficial to improve load-bearing and load-transferring capacity of matrix. As a result, this composites show much higher mechanical properties. The flexural strength and modulus are 2.4 times and 1.3 times as those of the sol with larger particle size derived composites, respectively.

It is well known that grain-refinement has a positive impact on the mechanical properties of WC-Co cemented carbide. The effect of VC inhibitor and microwave on density, microstructure and mechanical properties of the sintered WC–12wt%Co alloy was investigated in the present study. The ball milled WC-12wt%Co-xVC composites were compressed and fabricated by using microwave sintering method. The experimental results indicate that the microwave sintering cycle was significantly shorter to that of vacuum processing, and the density of bulk alloys increased with VC inhibitor contents and microwave sintering temperatures. Moreover, the microstructure observation of the sintered samples suggests that VC inhibitor had prominent inhibitory action on WC grains in microwave exposure, and the WC average grain size of alloy with 0.7wt%VC inhibitor was 0.43μm when the sintering temperature reached 1420°C. It is also evident that WC-12wt% alloys with an appropriate proportion of VC inhibitor exhibited higher hardness (92.1HRA) and better transverse rupture strength (2380MPa). And finally the mechanism of inhibitory effects on WC grains under microwave irradiation was discussed.

Electron beam (EB) annealing was used to acquire a reasonable and stable component in Si-Sb-Te material. For Si2Sb2Te5phase change material, EB irradiation can induce phase separation and some regions have remained unchanged, which manifests as SixSb2Te3. The component of these steady areas was considered as reasonable in which Sb2Te3is a stable compound. The crystallized Si3.3Sb2Te3film after EB irradiation exhibited nanoscale grains with well-proportioned distribution and these grains were all with Sb2Te3structure surrounded by amorphous. This unique structure brings fast phase change speed which is at least 12 times more rapidly than Si2Sb2Te5material because it localizes atoms’ diffusion in a nanoarea during reversible phase transition process.

The present situation of precision hill-seeder with whole plastic-film mulching on double ridges on the northwest arid areas was introduced and the structure, performance and characteristics of two different types of precision hill-seeder were analyzed and discussed. On the basis of comparative analyses and research, problems of current hill-seeder were put forward. Combined with the agricultural technology of double ridges, pneumatic and vertical insert precision hill-seeder was designed. Thus, the future research direction of precision hill-seeder was pointed out and the design basis and reference was provided for research of the related precision hill-seeder.

The pale geomorphology of Lower Xingouzui Formation is controlled by synsedimentary faults. The pale geomorphology controls the distribution of depositional systems, the development of underwater distributary channel controlled by groove and structural slope break belt, combination features of underwater distributary channel and mouth bar controlled by sedimentary slope break, beach bar developed in paleo-uplift, shore-shallow lacustrine and semi-deep lake developed in sag zone.

This paperdescribes an approach based on Wi-Fi technology to remotelycontrol the stepper motor. Through usingMCU Nested Vectored InterruptController (NVIC) and timer, the stepper motor would run smooth without intervalor frame miss, which could happen due to the problem of unstable Wi-Fi connection.The drive board and Wi-Fi module were also re designed to smooth the runningprocess of stepper motor.

Specific to the demand for the actual operation, this paper calculates short-term failure rates of various types of elements by adopting improved conditions dependent model: temperature-dependent element aging failure model, weather-dependent occasional failure model, current-dependent overload protection model, and processes a short-term reliability assessment by forward failure diffusion algorithm. Example analysis is simulated by 11kV distribution network of IEEE RBTS Bus-2 system to prove the reliability assessment model, the reliability assessment process are effective and provide on-site operation and maintenance personnel with guidance for decision making in the short-term scheduling and online operation.

Based on well logging and seismic calibration, the approximate paleo-level method was used to recreate the palaeotopography before deposition of Yageliemu stage, and then the study area was subdivided into three geomorphic units, high uplift, slope and depression. The braided river delta, oxidized shallow water delta, bank-bars as well as lacustrine sedimentary systems were identified through cores, mineralogy and logging data. Via debris composition, heavy mineral, seismic property studies, the lateral distribution of sedimentary systems were identified. This research revealed that the source to sink systems in study area are obviously controlled by topography, and there are two source districts, uplift and south-east, and braided river delta sediments developed in both the south and north sides of the eroded paleo-unplift. The southeastern source lack sediments supply, therefore only small oxidized shallow delta developed.

The singularity, namely, the output movement of the mechanism is uncertain due to kinematic bifurcation at the singular position, is the intrinsic characteristic of mechanism, resulting in movement out of control. To find a practical solution for this vexed question to make mechanism able to avoid its singular position is the greatest challenge in the field of mechanism. Based on the study of the planar four-bar linkage with singularity, the ideology of introducing self-adaptive mechanism theory into the solution of avoid singularity problem is firstly put forward in this paper. Using self-adaptive mechanism to complement the out of control parameters of singular position can make the mechanism have the ability to avoid singularity. Then the mechanism passes through the singular position smoothly with determined movement and load capability. Finally, the purpose of avoiding singularity is achieved.

As a multipoint differential data transmission electrical specification, RS485 bus has become the industry one of the most widely used standard communication interface. This communication interface allows the simple multi-point two-way communication on a pair of twisted pair, with which the noise suppression capability, data transfer rate, cable length and the reliability is unmatched by other standards. But this way of differential signal transmission is highly susceptible to common-mode interference, EMI electromagnetic interference and strong signal interference. In this paper, optical isolation devices were adopted on RS485 bus, which can effectively solve the interference problem of signal transmission process.

The experiment proved the effect of burning urban domestic wastes on alkali-resistant bricks and spalling-resistant high alumina bricks by the Static crucible method. The result indicates that the main erosion mechanism is slag permeable and slag erosion. Burning the waste will emit high temperature gases containing alkali, sulfur and chlorine, and the gases react with refractory materials contribute to the formation of sulfate, chloride and compound salt, which deteriorate and invalid refractory gradually. Through SEM, it is observed that the loose structure of metamorphic layers and easily spalled during thermal stress.

This paper sets the ancient landslide in Huale coal mine in Guizhou as the research object. The in-situ geological exploration and field survey to determine the nature and activity history of the landslide; By using the methods of drilling and pitting, geology structure characteristics of the ancient landslide could be determined; the sliding surface is obtained by field sampling test, rock and soil physical and mechanical characteristic; Through rationally designed dip tube, the paper repeatedly monitors the underground displacement with the borehole inclinometer, mastered the ancient landslide slip surface sliding depth and the location. On this basis, the paper analyzes the activation factors and sliding mechanism of the ancient landslide. Direct cause of the activation of the ancient landslide is mine industrial site construction of the damage to the front of the ancient landslide. Ancient landslide sliding mechanism of the ancient landslide itself exists the weakness of sliding surface, the front is damaged due to landslide, leads to landslide.

With the wide application of Internet technology, the embedded system is becoming more and more to develop in the direction of the network. The combination of embedded devices and the Internet represents the future direction of development of embedded systems. In this paper, a microprocessor-based embedded Ethernet solution was presented. The collaborative software and hardware design thought was used in system. TheμC /OS-II operating system, joined the TCP/IP protocol stack, was transplanted to the embedded Ethernet platform. The test results proved that the embedded Ethernet system network communication is stable and reliable.

SiC nanopowder, polycarbosilane and divinylbenzene mixed slurries were prepared for viscosity measurement, which were used as matrix source of ceramic matrix composites. Results showed that apparent viscosity of the slurries increased with the increase of the content of SiC particles. The slurries with 50 nm SiC particles showed a low viscosity as compared with those slurries with 20 nm or 120 nm SiC particles at the same content of SiC. In particular, when the viscosity of slurry was higher than 30 mPa•s, the slurry could not be used in the test. Three-dimensional carbon fiber (3D-Cf) preforms were infiltrated with the aforementioned slurries. Addition of the nanoSiC powder as the inert filler in the slurries led to reduce the porosity and the infiltration–curing–pyrolysis cycles to manufacture 3D-Cf/SiC composites by the subsequent polymer impregnation and pyrolysis (PIP) process. Characterizations of the composites showed that the maximum flexural strength of specimen in the composites was 326 MPa and its fracture toughness was 10.5 MPa•m1/2.

There are many engineering characteristics for soft ground. It is an urgent problem for engineering construction to predict settlement according to the features of soft ground and existing settlement data. In this paper, we used the measured settlement data of soft ground, then come up with the prediction method of soft ground settlement based on the BP artificial neural network in the Matlab simulation environment. This method can modelling highly complex and nonlinear earth structures directly based on real samples. Practical test showed that this method has a high degree of accuracy, and it is very valuable to instruct construction and guarantee the stability of the ground.

Coalbed methane resource is rich in China, however the original fracture system is complex and the fracturing effect, the fracturing crack initiation and propagation law are different from conventional formations, so the conventional hydraulic fracturing experience is not applicable. This paper summarized previous experience, systematically discussed the main factors and influences of coalbed methane fracturing, analyzed the research progress of CBM for fracture propagation law and the main problems and put forward some recommendations on the development direction of theoretical research on coalbed methane fracturing, which are necessary for depth research of coalbed methane fracturing crack propagation law.

Inverse dynamics problem of large-displacement motion simulator is solved by Roberson-Wittenburg method. Simulation graphs plotted by matlab prove the validity of solution. This paper can be used in control studies of motion simulator.

Because of the reliability requirement for the motor driving system in practical application, and based on analysis of the working principle of a fault-tolerant inverter, the direct torque control (DTC) for brushless direct current motor (BLDCM) fed by four-switch three-phases inverter (FSTPI) when the inverter faults is widely studied. According to the characteristics of (BLDCM), the voltage space vector for BLDCM-DTC fed by FSTPI is redefined due to the dissymmetric voltage space vector of TPFSI. To reduce the number of power device switching, the implementation method of four-switch SVPWM with seven-segment scheme was presented. Therefore, the system model is established as a result of the detailed analysis of voltage space vector and the control principle of the BLDCM-DTC without flux linkage observation fed by FSTPI. The validity and effectiveness of the proposed scheme have been verified through the simulation and experimental results.

It is a general processing technology that multi-axis NC machine tools is used for machining impeller at present. In order to improve the machining accuracy of the five-axis NC machine tools, the paper analyzes the computing interpolation error of the Multi-axis CNC system in detail. Some of the measures of tools selection have been proposed in purpose of diminishing the accumulative error of the system. The paper also establishes the optimized objective function to optimize the process parameters of the CNC machining based on the material removal rate. All these measures will improve the machining efficiency significantly and increase the stationary of the machining process.

This paper proposes a practical method for the synthesis of rigid-body guidance mechanism by dividing the guidance task into path and pose generation independently. As a first step, based on the mechanism combination principle, a basic four-bar mechanism for path generation is synthesized and a binary-link is combined to the mechanism for achieving the execute link’s poses, then the potential kinematic chain with ability to realize the desired coupler poses is selected from all of the combination possibilities. And then a strategy by fixing a Cam to the basic four-bar mechanism to control the linkage poses is also proposed. Finally, the Cam’s profile is synthesized and the combined cam-link mechanism is able to guide the coupler through all desired linkage positions. One example is presented to validate the proposed guidance mechanism synthesis method.

Metallographic microscope is an indispensable tool for metallurgical studies, which played an important role in materials science research and experiment. For a long time, metallographic examination results are output in the form of a photosensitive film. This film-based imaging record way has become increasingly unsuited to the study of modern materials science. Digital metallographic microscope is a modern high-tech product, which combines optical microscopy techniques, photovoltaic technology and computer image processing technology. A digitization method is presented for the traditional metallographic microscope in this paper. Experimental results show that the digitization for metallographic microscope is feasible, which meets the requirements of modern materials science research.

RFID is a technology that uses radio frequency signals coupled to the space (alternating magnetic or electromagnetic), to achieve the purpose of non-contact transfer of information and automatic identification. In this paper, RFID reader system is designed based on the MF RC500. Compared with the automatic identification technology such as the barcodes, magnetic cards and IC cards, The RFID reader has many outstanding advantages: firstly, it is safe and suitable for high security terminal. The second, a plurality of electronic tags can be recognized simultaneously. The third, there is no mechanical wear. The fourth, it is convenient to use with non-contact operation and without human intervention when identifying.