Abstract: In order to improve properties of WCu alloy, the different La were introduced into W skeleton during sintering process. The hardness, electrical conductivity and the compression stress were tested, and the microstructure and composition were characterized by a scanning electron microscope. The results show that an appropriate rare earth La addition can purify W/W interface, enhance the bonding of W /W, and improve the densification and the integral properties of WCu alloy. In the range of experiments, WCu alloy with 0.3wt% La addition has the largest hardness value of 198HB and the maximum compression stress of 823N/mm2. In comparison with that without La addition, 0.3wt%La addition decreases the electrical conductivity slightly, but improves the hardness and the maximum compression stress significantly, which are increased by 23.6% and 57.2%, respectively.
Abstract: Electrospinning is a convenient method used in the preparation of ultrafine oil sorptive fibers based on Ethylene-propylene-diene (EPDM), Electrospun fiber diameter, varying in large from micrometer to nanometer, mainly depends upon the solution concentration, which has great influence on this function fiber’s sorption ability. The non-linear relation between mean fiber diameter (d) and solution concentration (C) was investigated and it follows a simple scaling law in the form . This relationship can be used to predict the target fiber diameter and guide the processing technique. The effects of various C on oil sorption ability were investigated in a batch-sorption technique. A comparison of the kinetic models, showed that the removal rate fit the first order kinetic model well, which suggested the sorption process is rapid, can reach equilibrium within a short time.
Abstract: In order to control the print-through, the value of print-through resistance (PTR for short) was put forward to predict the print-through of lithograph. For 5 given paper samples, the relationships between their PTR and print-through (expressed with ΔEab*) was explored under three sets of printing condition in this paper. The results showed that lower printing press and higher printing speed were helpful to reduce the print-through. And under the same printing conditions, the print-through value of cyan ink print was slightly larger than that of magenta ink print. In addition, the PTR increase could lead to the decrease of the print-through value. In particular, no matter what kind of conditions, the print-through value was almost smaller than 4 NBS when the PTR of those paper samples was larger than 73%, which could be look on as the absence of print-through phenomenon.
Abstract: In this paper, the flow characteristics of the whole-rounded enlarged-hole baffle heat exchangers are experimentally studied with the stress on the shell-side pressure drops. It is found that the shell-side pressure drops for the whole-rounded baffles with the enlarged holes are greatly decreased. Compared with the square layout, the enlarged-hole whole-rounded baffles in the case of triangle layout is even more effective in decreasing the pressure drop. The shell-side pressure drops for the heat exchangers with the enlarged-hole whole-rounded baffles are proportional to the square of the flow rate.
Abstract: This paper makes a comprehensive study of side slope control nearby apartment buildings in a university in Southwest China by investigating its geological condition, making a stability analysis, calculating landslide force, and designing a control project by adopting anti-slide piles plus drainage system, and explores the reasonable pile gap on the basis of anti-sliding stability and security and makes a conclusion.
Abstract: A numerical model is presented to analyze effect of wheel/rail friction on rolling contact fatigue. A three-dimension finite element model of rail is built up to investigate the rail stresses and strain around wheel/rail patch. Then, based on the critical plane concept, a new model was proposed to predict the rolling contact fatigue (RCF) crack initiation life under different wheel/rail frictions by using stress and strain on the critical plane as fatigue parameter. The numerical results obtained show that the wheel/rail friction coefficient has a great impact on the fatigue crack initiation life.and the curve of fatigue crack initiation life under different wheel/rail friction coefficient is roughly "S" type. The results are very useful in the wheel/rail friction management and determining grinding interval and grinding removal.
Abstract: Nano-scale Ba0.75Al10.9O17.25:0.1 Mn2+ with spherical and rod-like morphologies were prepared by using a reverse microemulsion system. The measurements of their luminescent properties in VUV region revealed that there are obvious differences between these two samples. After analyzed by using electron diffraction (ED) and electron paramagnetic resonance (EPR), it is found that these differences between the optical behaviors of these two samples could be caused by different crystal growth orientations of these two samples, which may influence the formation of Mn2+-Mn2+ paired centers and thereby cause these difference.
Abstract: In this study, the feasibility of a new chemical agent named zero-valent iron (ZVI or Fe0) was used to investigate for removal of NH4+-N from coking wastewater. Reaction pH, dose of Fe0, initial NH4+-N concentration and temperature were considered variable parameters. The pH was observed as the major critical parameter. The removal rate of NH4+-N decreased as the pH increased from 3 to 6 and then increased from pH 6 to pH 9. At pH of 8.0 about in coking wastewater, the NH4+-N removal might be depended on the types and quantity of corrosion products on the surface of Fe0. The removal rate of NH4+-N increased with increase of temperature in the studied range of 10–60°C. At an initial NH4+-N concentration of 134.17 mg/L, Fe0 concentration of 6 g/L, temperature of 60°C and initial pH of 8.0, the removal rate of NH4+-N increased to 54.94%. The dose of Fe0 is determined according to the nitrogen content in coking wastewater.
Abstract: LiFePO4/C cathode materials for lithium ion battery were prepared by solid-state method from using Polystyrene (PS) micro-spheres as new carbon source. The structure, morphology and electrochemical performances of LiFePO4/C were investigated by X-ray diffraction (XRD), scanning electronic morphology (SEM) and galvanostatic charge-discharge tests and cycle voltammetry (CV). The results demonstrate that LiFePO4/C have single olivine type structure with small particle sizes. The electrochemical test results show that the residual carbon produced by the pyrolysis of PS microspheres with functionalized aromatic groups exhibites a better discharge capacity in the LiFePO4/C composite. The LiFePO4/C cathode material with 7 wt% PS delivers an initial discharge capacity of 141mAh/g at 0.1C and between 2.5-4.1V, and displays excellent capacity retention. The composite material exhibited a higher peak intensity and a smaller voltage difference between the oxidation and reduction peak, indicating a good electrochemical reaction reversibility.
Abstract: Experimental studies on thermal strain of aerial laminated glasses by virtue of Moire Interferometry were done. The experimental results were as follows: in the U patterns of moire interference fringe, with temperature increasing, the fringes became denser and the thermal strain was augmented. In the V patterns of moire interference fringe, the sequence of the fringe patterns increased is intermediate film layer, external shielding layer and main bearing layer, respectively. The U and V fringe patterns results analyzed by digital image process system indicate that, with temperature increasing, the strain εx decreased. Because the difference of coefficients of thermal expansion of three materials is very large, the thermal strain is generated significantly, and the interlayer thermal shear strain exists in the end and intermediate position of the free boundary of the laminated glass.