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Four different plastic deformation modes of pure molybdenum in powder metallurgy were studied, including single tensile, single torsion, tensile-torsion and compressive-torsion. Then the influence of these four plastic deformation modes on the micro-mechanical properties of pure molybdenum in powder metallurgy was studied by the micro-indentation method. The results show that the accumulated strain before deformation instability or fracture of the studied material caused by different plastic deformation modes is different, while showing a regular variation. And the mean indentation hardness along the radial direction of the sample also change regularly, which results in different strengthening effects on the molybdenum material itself. The damage inside the deformed material will cause the apparent modulus of elasticity measured by micro-indentation to decrease significantly.

To improve the pressure-bearing capacity, a novel high-pressure die with cemented carbide as the first layer of supporting ring was designed. The novel high-pressure die increases the ultimate load-bearing capacity of the high-pressure die by increasing the pretension of the tungsten carbide cylinder. As the volume of the cemented carbide increases, the difficulty of manufacturing increases, therefore, to reduce the manufacturing difficulty of the cemented carbide supporting ring and reduce the shear stress of the supporting ring, the cemented carbide supporting ring is splited. And through reasonable derivation calculations, the calculation formula suitable for the optimal interference amount of the high-pressure die is obtained. The numerical analysis results show that: when a pressure of 6.2 GPa is applied on the inner wall of the tungsten carbide cylinder, high-pressure die mold that uses cemented carbide as the first layer of support ring (hereinafter referred to as double-layered cemented carbide novel high-pressure die) is lower than the ordinary high-pressure die in term of circumferential stress by 93.34%. In terms of von Mises stress by 21.4%, and term of maximum shear stress by 21.37%. The three principal stress images of the two molds are drawn, which proved that the double-layered hard alloy novel high-pressure die can fully exert the performance of the material and can withstand greater pressure.

Fe-6.5wt%Si steel is an excellent soft magnetic material due to the near-zero magnetostriction and low core losses. In this study, a 0.3 mm-thick grain-oriented 6.5wt%Si steel sheet was produced by a novel strip casting and two-stage rolling. The microstructure and texture evolution were investigated with a special emphasis on the nucleation and growth of Goss grains. The thin normalized strip was composed of large columnar grains and small equiaxed grains. During intermediate annealing, Goss grains nucleated in the shear bands of the deformed //ND grains, and the deformed {111} grains provided most of the nucleation sites. After primary annealing, the Goss grains distributed across the entire thickness, which was different from the conventional rolling route. The fraction of high-angle boundaries (20°-45°) surrounding the Goss grains was apparently higher than those of the matrix grains, which promoted the abnormal growth of the Goss grains during secondary recrystallization.

Pre-tensing the CFRP strip strengthening RC column can improve the strain lag of the confined concrete and avoid unloading of column in advance. The pre-stress of strip has an important influence of strengthen. Stress loss of the strip pre-tensed by using the device proposed were investigated by using an experimental test. Firstly, the reasons for the stress loss of strip were analyzed according to the working principle of the device and the strengthening procedure. Then the primary causes of the stress loss, such as friction, relaxation and removing device, were experimentally tested. The influence of the pretension, detail and sectional geometric dimension on the stress loss of the strip were studied. The results show that all three types of pre-stress losses increase significantly with the initial stress. Increasing the cross-sectional size would reduce the relaxation and unwinding losses, but it has little effect on friction losses. The influence of fillet radius on the pre-stress loss was negligible, but in order to avoid premature tearing of local CFRP caused by stress concentration, the chamfer should be made as large as possible within the thickness of concrete protective cover. The test also found that friction was the main cause of stress loss, and friction loss accounts for more than 90% of the total loss.

Self-compacting steel fiber concrete must meet the strength standard after steel fiber is added and must have good fluidity. The test results show that the addition of steel fiber to concrete will affect the fluidity of concrete. Compared with ordinary concrete, the addition of steel fiber will improve the compressive strength and flexural tensile strength of concrete to varying degrees. The mix proportion test can be carried out in stages, i.e. the mix proportion meeting all performance indexes used is determined first, then steel fiber is added and adjusted to determine the best mix proportion.

In this study, the ultrafine copper-based powders were fabricated by a facile two-step chemical reduction method. Glucose (C6H12O6) and ascorbic acid (AA) were taken as a pre-reductant and a second reductant, respectively. Polyvinylpyrrolidone (PVP) was applied as the capping agent. Effects of parameters, such as glucose content, PVP content and PH value on the ultimate reduction products were analyzed. Microstructure and composition of the products were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). It was found that when the amount of glucose was increased from half to full and then excessive, the powder gradually changed from flaky to spherical, from pure copper powder to a mixture of copper and cuprous oxide (Cu2O). With the amount of PVP increasing from 0g to 0.64 g, the shape of the pure copper powder changed from cubic to spherical or HYPERLINK "javascript:void (0);" icosahedron. When the PH value changed from 10-14, the powder changed from spherical to regular octahedron and Irregular polyhedron, from pure copper powder to pure cuprous oxide powder. Therefore, copper-based powders with different morphologies and different compositions can be prepared by changing PH value and the amount of reductant.

The failure analysis of 110S tubing during acidizing process was addressed. Results showed that serious pitting corrosion occurred on the outer wall of tubing, and there was no obvious pitting on the inner wall. The maximum pitting depth on the outer wall was 1019 μm. According to the results of simulation corrosion test, needle-shaped pitting appeared on the sample surface in the test without inhibitor, the maximum depth of pitting was 158 μm; and no pitting was found on the sample surface in the test within 1.5% TG501 inhibitor; the original pitting were deepened after spent acid test, and the sample with no pitting at the beginning also showed deep pitting corrosion after 96 hours spent acid test. It was indicated that the spent acid accelerated the development of pitting significantly. The external surface corrosion of the 110S tubing was caused by the chemical reaction between the high-concentration acidifying liquid and the outer wall of the tubing. There is a gap between the tubing and coupling threaded connection, which caused the acid solution entered into the thread position, and hence the severe corrosion of the thread and pin end of the tubing happened, the joint strength was continuously reduced with corrosion development till the tripping of the coupling, and then the lower string dropped. Some suggestions were proposed for avoiding or slowing down this kind of failure based on this study.

This experiment was conducted to study the new shoot, bud and leaf of Fuding Dabai Tea, which was picked and purchased from Zhongfeng Tea Garden in Ya'an famous mountain area. The sensory quality, contents, pesticide residues and heavy metals of fresh leaves and green tea were studied and compared. The total soluble solids content and turbidity of water samples before and after the cleaning process were determined. The results showed that: (1) the weighted total score of sensory evaluation of finished tea added with fresh leaf cleaning technology was 91.15, which was 2.45 points higher than that of the control (without fresh leaf cleaning), and increased by 2.76%. (2) Fresh leaf cleaning process can significantly reduce the content of tea polyphenols, caffeine and water extract, and the ratio of phenol to ammonia, but has no significant effect on the content of amino acid and soluble sugar. (3) The total soluble solids of Q 2 are 4.3 times as much as Q1, and the turbidity of Q2 is 37.2 times as much as Q1. Cleaning process of fresh leaves can significantly reduce the indexes of agricultural residues and heavy metals. In conclusion, the cleaning process of fresh tea leaves can improve the sensory quality of tea to a certain extent, significantly reduce the content of bitter and astringent substances in tea leaves, effectively clean the surface impurities of fresh tea leaves, reduce pesticide residues and heavy metal content.

In order to optimize the layout and economic exploitation of horizontal fracturing wells and completion in shale gas reservoirs, we propose a model for evaluating shale gas fractured sections based on an improved principle component analysis (PCA) algorithm with logistic regression. The 229 gas production sections in 22 fractured shale gas wells in the main block of the Fuling Shale Development Demonstration Zone were selected, and PCA is used for dimensionalite reduction. According to the PCA results, 6 key parameters are chosen to determine the productivity of fractured wells. Taking the probability distribution of high production after fracturing as the research objective, a logistic regression discriminant model was constructed using the dichotomy method. The prediction results show that the model has 82.1% accuracy and is reliable. The model can be used to classify and gas wells to be fractured, and it provides guiding significance for reasonable optimization of well sections in the area selected for fracturing.

Nickel-rich layered oxides (Ni ≥60%) are considered as the most promising cathode materials for lithium-ion batteries due to its high energy density and low cost. However, its cycling performance is seriously influenced by the synthesis condition, like the sintering temperature, time and atmosphere. Herein, we investigate different properties of LiNi0.83Co0.11Mn0.06O2 (LNCMO) sintered from 720 to780 °C, and the cathode calcined at 760 °C display the most perfect layered structure and the uniform distribution of primary particles size. Therefore, the LNCMO sintered at 760 °C exhibited the best rate capability of 118 mAh·g-1 at 10 C and the highest capacity retention of 95.44 % after 100 cycles at 1 C. Our results indicate that the cycling performance and rate capability of LNCMO are heavily depended on the sintering temperature.

Comprehensive analysis on the requirement and evaluation result of pipeline steel for sour service is carried out in this paper. So as to provide technical support for the development of the high toughness sour service pipeline steel with low manganese content.The evaluation results shows that the high toughness sour service pipeline steel with low manganese content has excellent comprehensive properties, and the excellent comprehensive mechanical properties and corrosion resistance properties of trial products are achieved through reasonable composition and micro-structure design. The HIC and SSC test result complies with pipeline steel requirement for sour service drafted by major international manufacturers. In order to guarantee the application prospect of the trial products, the weldability of the sour service pipeline steel is analyzed finally, and the test result shows that HAZ softening can be improved when the cooling rate was higher than 20 °C /s.

During the process of Carbon Capture and Storage, some impurity may be found in the supercritical CO2fluid. The changes in corrosion of X70 Steel in water-saturated supercritical CO2system caused by impurity has been studied by the simulation experiment. The average corrosion rate was got from weight loss measurement. The morphologies and compositions of corrosion products were analyzed by SEM, EDS and XRD. It was observed that the existence of separate impurity would aggravate the corrosion of X70 steel in the water-saturated supercritical CO2system. The average corrosion rate was the highest when NO2or SO2was included, followed by H2S, and the average corrosion rate was the smallest when O2was contained. Among them, X70 steel suffered local corrosion when NO2was contained. The corrosion scale was monolayer structure of FeCO3under the supercritical CO2-H2O system. After the addition of O2, Fe2O3appeared in the corrosion scale, indicating that the oxygen corrosion process occurred. While with the addition of H2S, corrosion scales were double layers. FeS was mainly present in the outer layer. The corrosion process was controlled by CO2and H2S. The corrosion products were mostly FeSO3·xH2O and a spot of FeCO3when SO2was contained. SO2mainly governed the corrosion process. Besides, corrosion product was Fe2O3without FeCO3in the supercritical CO2-H2O-NO2system, NO2completely controlled the corrosion process.

ELID ultra-precision grinding mirror surface can achieve nanometer precision. However, after the grinding wheel passivates the abrasive particles in electrolysis, it is easy to scratch the ultra-precision ELID grinding surface into the grinding process. In order to solve this problem, a non-abrasive grain α-Fe bonded grinding wheel is propose, which contains no abrasive particles. After electrolysis, oxide film is formed on the surface of the wheel. In ultra-precision ELID grinding, there is no abrasive particles involved, only the polishing effect of oxide film. There is no need to worry about the scratching of exfoliated abrasive particles that have been machined on ultra-precision ELID surfaces. Thus achieving extremely high surface accuracy.

The worm-like morphology of silver sulfide (Ag2S) was successfully prepared via hydrothermal reaction at 150°C by using silver nitrate (AgNO3) and thioacetamide(CH3CSNH2) as both the sliver sources and sulfur sources, β-cyclodextrin as the template agent, and water as the solvent. The worm-like of Ag2S are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), x-ray photoelectronspectroscopy (XPS), energy dispersivex-ray (EDX), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SEAD). Ultraviolet-visible spectra (UV-vis) and photoluminescencespectroscopy (PL) were used in an optical study of the products. The results showed that the existence of β-cyclodextrin is crucial to the formation of worm-like Ag2S, and the optoelectronics test results showed that the sample have a broad absorption in ultraviolet and visible light region.

The shrinkage of concrete is one of the main causes of cavity in concrete filled steel tube (CFST). In this paper, the effect of a kind of lab-made expansive agent on the deformation of CFST is studied. The laser displacement sensor combined with the round straight steel tube mould was adopted to test the deformation of concrete from the initial setting to 1 day after pouring, and the mechanical micrometer method was used to test deformation after 1 day in the laboratory. The full-scale model test was carried out to monitor the effect of expansive agent in CFST at the project site. The results show that, the addition of expansive agent produced significant expansion in the first 3 days, with the expansion basically compensating the autogenous shrinkage of the concrete; influenced by thermal deformation, the constraint action of steel tube to the core concrete in temperature rise stage was far greater than that in cooling stage. Compared with expansion produced in temperature rise stage, it is more important to produce expansion in cooling stage to solve the cavity problem of CFST.

PVDF-HFP nanofibers are reinforced by (0, 10, 16 and 30wt% ) of butadiene rubber (BR) and are crosslinked by the UV curing during the electrospinning process. These electrospun clothes are soaked with 70wt% uptake of EMI-Tf ionic liquid for solid state electrolytes applications. These electrolytes are investigated by a broadband dielectric spectroscopy over a wide temperature range from-40 to 80 OC. It is found that the temperature dependence of conductivity of all the samples not only follow the VFT relation but also follow the Debye-Stokes-Einstein relation implying the coupling between the ionic conduction and the segmental motion of the polymer matrix. Also, the results indicated that the addition of butadiene rubber did not significantly affect the conduction behavior of the electrolyte. Moreover, the conductivity of all the electrospun cloth electrolytes is much higher than that of the solution casting film.

Precision grinding is generally used as the final finishing process, and it determines the surface quality of the machined component. It’s very difficult to achieve on-line measurement of the surface roughness. The purpose of this research was to study the surface roughness prediction and avoid the defect happening in the grinding process. A surface roughness prediction model was proposed in this paper, which presented the relationship between surface roughness and the wear condition of grinding wheel and grinding parameters. An AE sensor was used to collect the grinding signals during the grinding process to obtain the grinding wheel wear condition. Besides, a fuzzy neural network was used to obtain the prediction surface roughness. Grinding trials were performed on a high precision CNC cylindrical grinder (MGK1420) to evaluate the surface roughness prediction model. Experiment verified that the developed prediction system was feasible and had high prediction accuracy.

Based on the experiment of milling aluminium alloy (7075-T651), the relations between the fractal dimensions of cutting forces with machining parameters are studied. Cutting speed, feed speed and cutting depth are considered as the process parameters. The cutting force in milling aluminium alloy operation are measured and the fractal dimension are calculated using the algorithm of correlation dimension. From main effect plots the fractal dimensions of three directions of cutting forces are reduced with the increase of cutting speed and increased with the increase of feed speed and cutting depth. The mathematic models of fractal dimension of cutting force are developed using response surface methodology (RSM). The results of the ANOVA show that feed speed and cutting depth have remarkable influence to fractal dimension Dx and Dy, cutting speed and feed speed for Dz.

Polyethylene glycol (PEG-200) and itaconic acid (IA) were used as raw materials to compound macromer through esterification reaction. A new type of specialized water-coke slurry dispersant was synthesized by copolymerization of microware, sodium methallyl sulfonate (SMAS) and maleic anhydride (MA). The experiment showed that the concentration of slurry could be reached to 63% with the dosage of 0.2%, and the apparent viscosity was 1140.3 mPa∙s. Through the analysis of the infrared, the dispersant was confirmed to have polyethylene glycol branched chain and hydrophilic functional groups such as carboxyl or sulfonic group. When the concentration of dispersant was 30 g/L, the surface tension of water could be decreased from 72.70 mN/m to 45.50 mN/m. Furthermore, when the solution pH value was 9, the Zeta potential of semi-coke powder surface could also be decreased from-13.38 mV to-25 mV with the addition of dispersant. Thus, this dispersant could increase electronegativity of semi-coke powder surface, enhance steric-hindrance effect and prevent the phenomenon of powder flocculation and gather. Meantime, it also could reinforce the semi-coke hydrophilic by reducing the surface tension of water effectively. And then, the high performance water-coke slurry could be obtained.

Fine microstructure of twinning Martensite/austenite (M/A) islands in a X100 high strength pipeline steel were analyzed by the scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM), and a uniaxial compressive experiment of micro-pillar for a twinning M/A island was conducted in present paper. The experimental results showed that M/A islands in X100 pipeline steels were consisted of retained austenite and nanoscale twins with sizes of less than ten nanometers. There were a few small blocks of nanoscale twins in an M/A island. Volume fraction of twinning M/A islands had an important effect on mechanical properties of X100 pipeline steels, with the increase of twinning M/A islands fraction, yield strength of X100 pipeline steel increased, and impact toughness of X100 pipeline steel decreased. The micro-pillar compression showed that the nanoscale twinning M/A island exhibited the higher deformation hardening during the compressive test, and its uniaxial compressive strength could up to 1.35GPa ultrahigh stress level.

Artificial neural network (ANN) gets a lot of applications in predicting flow stress of steels at high temperature. However, few studies have been devoted to simultaneously predict flow stress of several steels by ANN. The purpose of this paper is to determine the effect of ANN on simultaneously predicting flow stress of several steels. Based on the results of previous compression experiments of four types of microalloyed forging steel, using the mass percentage of major chemical composition of the steels, such as as C, Mn, Si and V, and deformation temperature, strain rate and strain as input variables, a three-layers back propagation neural network was established as the constitutive model for them. Standard statistical methods were employed to quantitatively measure the accuracy of predicted results by the model. The calculated correlation coefficient and the average relative error absolute value between the predicted values by the model and experimental values were 0.9982 and 2.4181%, respectively. In addition, the relative error between the two kinds of values was calculated, and for more than 89% samples, the relative error was within ± 5%. The results show that the developed constitutive model can predict the flow stress of the four types of microalloyed forging steel accurately and simultaneously.

Monodisperse nickel phosphide (Ni5P4) nanoparticles supported on carbon (Ni5P4@C) were in situ synthesized by one step solution-phase route, in which the mixture of trioctyloxide (TOPO) and trioctylphosphine (TOP) was used as solvent, capping agent and phosphor source. Ni5P4nanocrystals were in situ coupled by active carbon simply adding the carbon to the reaction solution. The as-prepared Pt-free Ni5P4 nanocrystals exhibit the enhanced electrocatalytic activity toward hydrogen oxidation reaction (HOR) compared to pure commercial Ni nanoparticles. Therefore, the obtained Ni5P4@C nanocatalyst appears to be promising non precious metal electrocatalysts for HOR.

The formation mechanism of α-Fe2O3 on iron-bonded diamond wheel surface by ELID grinding is presented here. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques were used to analyze the compositions of the oxide films. X-ray diffraction analysis demonstrated the existence of the diffraction peak of α-Fe2O3, which was observed in ELID grinding iron-bonded diamond wheel surface. To illustrate the correctness of our theory, X-ray photoelectron spectroscopy analysis was also performed. Results reveal that the characteristic spectrum of oxide film on ELID wheel has coincidence with the standard spectrum of Fe2p in α-Fe2O3. These results suggest the existence of α-Fe2O3 in oxide films on the grinding wheel surface. The potentiality that α-Fe2O3 can bring polishing effect to ELID grinding process has also been discussed. It helps understand how ELID grinding can achieve excellent surface finish for the workpiece.

Polyvinyl alcohol (PVA) fiber reinforced cementitious material (called PVA-ECC) has been intensively studied as a promising alternative to ordinary cement materials. While PVA-ECC has high stain capacity and ductility, its extreme high cost mainly caused by the high unit cost of used Japanese fiber has hindered its application in China. In order to reduce the cost of PVA-ECC, one type of inexpensive PVA fiber produced in China was used to develop a ductile ECC with deflection hardening and multiple cracking behaviors in this research. Compressive strength test, four-point bending test and uniaxial tension test were conducted to investigate the mechanical properties of the newly developed composites. The results show that ECC made with domestic ingredients exhibits large deformation and multiple cracking, revealing that it is feasible to produce low cost ECC material employing local PVA fibers.

With the extended applications of hexagonal silicon carbide (h-SiC) in the various fields, particularly in the application of the electronic devices, more and more attentions have been focused on the micro structures as well as their physical properties of h-SiC surface. In this study, we have performed the first principal calculations to compare the formation energies of four typical defects (Vc, Vsi, CI and SiI) on the 4H-SiC (0001) surface as well as in the interior layers. Due to the surface reconstruction and the reduced lattice constrain, the optimized structures of the defects on/near the 4H-SiC (0001) surface are quite different from the ones in the deeper layers. The distinguished formation energies as function of chemical potential indicate that we may control the defects concentrations in different layers by tuning the environmental conditions. This theoretical work provides a significant understanding to the formation mechanism of the point defects on the 4H-SiC surface, and paves a way to the modification of the SiC surface via electron irradiation or ion implantation with micro-defects introduced.

PLGA, poly (lactic-co-glycolic-acid), is a kind of biodegradable functional macromolecular organic compounds. PLGA, certified by the Food and Drug Administration (FDA), possesses desirable features of biocompatibility, nontoxicity and no immune response, and is being widely applied to human clinical medical research. Because of its biodegradability, simple synthetic methods, controllability of degrading rate and desirable plasticity, PLGA was applied in large quantity into the carrier materials which is to control the release in recent years, gradually propelling PLGA microsphere controlled release system to be the most ideal drug-carrier system at present. As the carrier of drug and genes, PLGA is mainly researched on its features as the carrier, synthetic methods, different surface modification methods, and the applications on different drugs, genetic treatments and genetic vaccines.

MgB2 powder was fabricated by sintering the mixture of pure Mg and B powder with atomic ratio of Mg : B=1:2. The magnetic property of the powder indicated that it was superconducting and its critical transition temperature was 39K. Titanium based MgB2 films were obtained by electrophoretic deposition method using Ni sheet as anode and titanium tapes as cathode. The films were annealed at 500°C for 2 hours, subjected to argon-hydrogen (95%Ar+5%H2) gas flow. The results of X-ray diffraction (XRD) analysis showed that the composition of the film was mainly MgB2. The observation under scanning electron microscopy (SEM) showed that the film of MgB2 was uniform and dense. The electrical resistivity of double-side MgB2 film was about 5.280×10-8Ω/m.

Precious metals are used widely in electronic industry because of their excellent heat resistance, corrosion resistance and catalytic property. Therefore it is important to recycle precious metals from E-waste. In this study, a new amid extractant N,N-Dimethyl-N,N-didecyl-3-thiopentanediamide (MDTDGA) was firstly synthesized through N-alkylated and N-acylation reaction. The extraction behavior of precious metals with MDTDGA in 80% dodecane-20% 2-ethylhexanol from hydrochloric acid was studied. The extraction ration increases with HCl concentration and extractant concentration, but it is not influenced by H+ concentration. It is indicated that the extraction of precious metals Pd (II), Pt (IV), Au (III) with MDTDGA is neutral coordination. High extraction efficiency of Au (III) of 99.5% using MDTDGA was obtained.

The reconstruction of defect profiles based on ultrasonic guided waves means the acquisition of defect profiles and parameters from ultrasonic guided wave signals. To achieve multi-resolution approximation, this paper proposed a reconstruction approach based on Radial Wavelet Basis Function Neural Network (RWBFNN), which combines wavelet analysis and neural network. Gaussian radial basis functions and Mexican hat wavelet frames are used as scaling functions and wavelet functions respectively. The training and testing samples contain simulation data and experimental data. The input data sets are defect echo signals, and the output data sets are 2-D profile parameters. To reduce the training time and simplify the profile reconstruction procedure without losing accuracy, Extreme Learning Machine (ELM) is adopted simultaneously. The results indicate that significant advantages can be obtained over other defect profile reconstruction schemes, and the accuracy of the predicted defect profile can be controlled by the resolution of the network with the lower computational complexity.

Lead zirconate titanate (PZT)-based nanocomposites embedded with ZrO2 nanoparticles were fabricated by citrate precursor route from metastable phases in situ. The effect of ZrO2 content on mechanical and piezoelectric properties of composites was investigated. m-ZrO2 particles covering 30-70 nm are dispersed homogenously inside the PZT matrix grain with stress strips around m-ZrO2 nanoparticles. The fracture mode changes from intergranular to intragranular with increasing the amount of ZrO2. Transformation toughening and nanoparticle dispersion toughening of ZrO2 contributed to the reinforcement of the PZT/ZrO2 nanocomposites. It is exciting to found that the mechanical properties as well as the piezoelectric properties were both increased compared with those of monolithic PZT when add a certain amount of ZrO2.

In this paper, we have synthesized new functionalized Al2O3 nanoparticles successfully via reaction, which was grafted polyurethane onto the surface of nanoparticles dispersed in n-butyl acetate. The structure, surface properties, and thermal stability of the functionalized Al2O3 nanoparticles were characterized by means of by FT-IR, TGA and SEM. The results showed that the surface of Al2O3 nanoparticles has been grafted with polyurethane (PU). Furthermore, Al2O3 nanoparticles was dispersed evenly in the organic solvent, which can show a long suspension stability near to 6 months without precipitation, indicating that this product is very useful to prepare stabilized coating nanocomposites.

Mixture powders with different ratio of Ag/γ-TiAl were deposited on titanium alloy by low presure plasma spray and thermal treatment was applied to convert the mixture coatings into Ti-Al-Ag ternary ones. The experimental results indicated that the oxidation resistance of ternary coatings was better than sheer γ-TiAl coating and increased with increasing Ag from 2at.% to 4at.% at 700 and 800°C. The outside oxide scale consisted of alumina and a small amount of rutile due to the insufficient diffusion of Ag in γ-TiAl.

The combination of FSW and SPF processing is one of most attractive fabrication method for the larger structures and integrate substructure to reduce the part count of aircraft assemblies and costs. One purpose of the SPF technology development is to decrease the forming temperature and increase the forming rate, then reduce cost and enhance the efficiency. Maybe FSW could supply another way to achieve this besides reduce the grain size by traditional rolling process. The purpose of this study is to indicate some new results of the superplasticity of weld nugget for the Ti-6Al-4V alloy. It is found that the temperature has no much effects on the superplastic tensile elongation of the weld nugget, and deformation rate has the contrary effects on the superplasticity to the traditional results, the elongation will be higher with the higher deformation rate. The mechanism will be discussed with the analysis of the microstructure by SEM. The tensile properties was tested after SPF process with a 60% strain.

By using self-designed non-thermal plasma reactor, the influences of discharge power, initial concentration of C3H6 and O2 concentration on NO pro-oxidation in C3H6/NO/N2/O2 mixture were studied. The obtained results indicate that with the increasing of discharge power, NO2/NOx ratio grows firstly and then decreases after reaching a peak value, while NOx conversion efficiency and N2O concentration gradually rise. Increasing initial concentration of C3H6 or O2 concentration would help to enhance NO oxidation efficiency. With the same discharge power, NOx conversion efficiency grows with the increasing of C3H6 initial concentration while reduces with the increasing of O2 concentration. Controlling the concentration of C3H6 and O2 in exhaust gas can lead the NO2/NOx ratio to reach 50%, which is benefit to NOx conversion with SCR system.

Diesel particulate filter (DPF) are considered to be the most effective means to reduce particulate emissions, and the key of DPF lies in their regeneration. O3 and O which have strong oxidability can be produced by non-thermal plasma (NTP) reactor. PM can be decomposed by these active substances to generate CO and CO2. The results show that PM deposited in the DPF can be removed by NTP technology without any catalyst and DPF can be completely regenerated at a lower temperature.

Reverse design based on CMM (Coordinate Measuring Machine) measuring has been used in the engineering design widely because of its higher quality, shorter manufacturing cycle and lower cost. The flexible rod is widely used in tension mechanism because of its large adjustable range, high tensile strength and good flexibility. The reverse design of a flexible rod based on CMM measuring is researched in this paper. The structure of the flexible rod was analyzed. The CMM digital measuring of the part has been completed and the data of measuring results is processed. The reverse 3D modeling and design of the flexible rod have been accomplished.

This study presents an experimental investigation of CO2flowing condensation at the saturation temperature of-10°C, mass flux in the range from 40 to 60kgm-2s-1and vapour quality ranging from 0.2 to 0.8, in a 6.52mm inside diameter horizontal tube. Previous research on refrigerant condensation has shown that under these conditions, CO2two phases are expected to develop as a stratified flow. The significant feature of the stratified flow heat transfer is vapour film condensation in the upper region which dominates the overall heat transfer process. Test series in this study confirm that the saturation-to-tube wall temperature difference has a significant influence on the condensing heat transfer coefficient when the temperature difference is within 3K. Comparisons between the experimental results and the predictions by the Dobson, Cavallini and Thome models show that CO2stratified flow condensation heat transfer coefficients are over-predicted by these models with mean deviations of 104%, 81% and 127%, respectively.

In this paper, PV module parameters of dust removal equipment are analyzed; the dust removal device model is established by using solidworks software; the motion simulation of removal process is conducted directly in solidworks motion simulation interface; a comparison of dust removal effects is made between the top-down and the left-to-right dust removal device at the same traction speed and brush dust removal brush rotation speed; a conclusion is drawn that brush traction speed, rotation speed, and helix angle have impact on dust removal effect and the two devices are close to each other in terms of dust removal effect, which provides some theoretical evidence for further design.

Mobile robots have been widely used for the good adaptability, payload capability. Robot cooperation brings benefits for the task in a multi-robot team. In this paper, the modular hardware design of a leader-follower mobile robot team is discussed, including the distributed control architecture and the electronic system of each robot of the team. The basic idea behind this paper is to introduce the design of the hardware and distributed control architecture, which mainly manages the distributed control system, consisting of microcontroller modules connected through a data bus. The research has a potential applying prospect in mobile robot tracing and locating in the future.

A new method to make SMA is developed by using SBS modified asphalt when the coarse aggregate steel slag and the fine basalt aggregate are selected respectively. The Mix Proportion is 1#(16-9.5mm, steel slag):2#(9.5-4.75mm, steel slag):3#(3-4.75mm, basalt):4#(3-0mm, basalt):5# (mineral powder)=38%:36%:8%:8%:10%.The optimal asphalt content (OAC) is 6.4%. The mass percentage of steel slag is reached 74%. The costs of this kind of high quality road material can be saved because the amount of asphalt is not increased. Based on Marshall Stability and Splitting Strength test, it is shown that the Marshall stability of SMA is 10.6 kN, dynamic stability is 7800, and tensile strength ratio is 89.2%. All above test values are superior to the standards in China's traffic regulations. The water permeability coefficient of SMA is 65, which means that SMA has an excellence Wear-Resistant performance. Therefore, SMA can increase the road useful life and reduce the road maintenance costs.

Characteristics of a water-cooled non-thermal plasma (NTP) reactor used to reduce diesel emissions were experimentally studied. The effects of working voltage, operating frequency and air flow rate on discharge power and concentrations of O3 and NO2 generated by NTP system were investigated at different surface temperatures of discharge zone. The experimental results show that, the discharge power of the reactor would increase with the increasing of working voltage, operating frequency and surface temperatures; air flow rate had little influence on discharge power; variation of O3 and NO2 concentration were different with the increasing of working voltage and operating frequency at different surface temperatures of discharge zone; when the surface temperature of discharge zone was constant, concentrations of O3 and NO2 increased firstly and then declined with the increasing of air flow rate; and concentrations of O3 and NO2 were higher at lower temperature.

A methodology is developed statistically to make MEMS devices robust to process variations to improve manufacturability and yield. Two approaches are applied to discuss the effects of multi-process variations. Comparisons have been made between the proposed method and Monte Carlo simulations, which confirm the robustness of the proposed one with performance error less than 4%. Experiments on beams and comb-drive resonator verified the effectiveness of the methodology and it is useful for practical device designs to be more robust to process variations and yield enhancement realization.

With the development of MEMS, more attention has been paid to the uniformity between the performance of the products in practical processing and the expected performance. A case study is conducted here with fixed-fixed beam and comb-drive resonator as the pattern to explore how geometry size deviation and geometry shape error influence the devices. It is discovered that the length, inclining profile and undercutting of the anchor is the key factor which influences the vibration mode of the fixed beam, and the geometry size and corrugating profile mainly affect the comb-drive resonator.

Ultra High Toughness Cementitous Composites (UHTCC) is a unique class of the ultra-ductile fiber reinforced cementitious composites. To meet the increasingly high requirements for materials in the construction, nanoSiO2, polyvinyl alcohol (PVA) and steel (ST) fibers were added into UHTCC to improve the mechanical property and control the crack width. Multiple effects of nanosilica and hybrid fibers on the flexural properties of UHTCC under three-point bending are evaluated. The results show that nanoSiO2 can increase flexural strength of UHTCC while equivalent deformability is guaranteed. When the addition of nanoSiO2 is 5%, the highest flexural strength is 15.77MPa. Moreover, hybrid steel-PVA fibers effectively mitigate negative influence from nanoSiO2 which induce the wider cracks of UHTCC as the stronger matrix. Comparing with mono fiber composites, hybrid fibers composites exhibit remarkably higher flexural strength and slightly lower deformation. The best performance are 24.85MPa and 2.34% at maximum volume of hybrid fibers.

Carboxylic multi-walled carbon nanotubes (MWCNTs-COOH) were modified by using ethylene diamine (EDA) to prepare amino-modified multi-walled carbon nanotubes (MWCNTs-NH2). The chemical structure of MWCNTs-NH2 was characterized by FT-IR, Raman spectroscopy, X-ray diffraction (XRD) test, TG analysis and elemental analysis. The results show that MWCNTs-COOH was effectively modified by EDA. Key words: MWCNTs-COOH; ethylene diamine; chemical modification; elemental analysis

The Cu/Zn-14.1Al-0.9Si/Al joints were joined by flame brazing and furnace brazing, respectively. The influence of brazing methods on the interface structure and property of Cu/Al brazed joint was investigated. It was found that the interface structure near Cu substrate of the joint with different brazing method are both Cu/diffusion layer/Al4.2Cu3.2Zn0.7 layer, but the thickness of the interface layer of the joint with the flame brazing (3-4μm) is obviously thinner than that of the joint with the furnace brazing (5-10μm). The filler metal zone of the joint with flame can not find the Cu-Al IMCs. Instead, the block CuAl2 IMC can generate in the filler metal zone of the joint with the furnace brazing. For thinner interface layer, the joint with flame brazing has higher shear strength of average 60.5MPa, which is 20.6MPa higher than that of the joint with air cooling (39.9MPa).

Based on the difficulty to accurately control temperature for torch brazing, the study is concerned with developing low-melting-point solders for brazing pure aluminum. For this purpose, Ge and Zn have been chosen to be added to Al-Si-based alloy. The melting characteristic, wetting property of solders with Al and mechanical property of the brazed joints were investigated. The results show that the addition of 10 wt. % germanium into the traditional Al-12Si (wt. %) filler metal causes its liquidus temperature to decrease by about 23 °C. An addition of 30 % zinc into such Al-Si-Ge ternary alloy will cause its liquidus temperature to drop further to 525 °C. The solders have good wettability with Al. With the increase of Zn content in the alloys, the spreading areas of solders exhibit nonlinear decrease, and there exist a very large value at the zinc content of 15%. When Al-Si-10Ge-30Zn solder was used to braze the pure aluminum, an optimized bonding strength of 116 MPa was achieved.

The Candide face model and the Face Action Coding System (FACS) are introduced in the paper. The relations of the positions of feature points of Candide-3 model and the action units of FACS are studied. The application system for computing the facial expressions of students in the experiment teaching process is developed. The feasibility of the application system is demonstrated.

Establishing the evaluation index system, from their own investment capacity, corporate external financing capacity of the two dimensions, using resultant weights and TOPSIS method for comprehensive evaluation of investment capacity of the power enterprises. Set a power company for example, results show that, the evaluation results are in line with the actual investment capacity situation of the power enterprises, the established evaluation index system and evaluation model has better applicability.