Applied Mechanics and Materials Vols. 395-396

Abstract: MIL-101, a metal-organic framework material, was synthesized by the high-temperature hydrothermal method. Triethylenetetramine (TETA) modification enabled the effective grafting of an amino group onto the surface of the materials and their pore structure. The crystal structure, micromorphology, specific surface area, and pore structure of the samples before and after modification were analyzed with an X-ray diffractometer, scanning electron microscope, specific surface and aperture tester, and infrared spectrometer. The carbon dioxide adsorption properties of the samples were determined by a thermal analyzer before and after TETA modification. Results show that moderate amino modification can effectively improve the microporous structure of MIL-101 and its carbon dioxide adsorption properties. After modification, the capacity of MIL-101 to adsorb carbon dioxide decreased only by 0.61 wt%, and a high adsorption capacity of 9.45 wt% was maintained after six cycles of adsorption testing at room temperature and ambient pressure.

Abstract: In this paper, the flue gas desulfurization gypsum (FGD) generated from thermal power plant is used to produce high strength gypsum. Compared with the properties of high strength gypsum using natural gypsum, the basic properties of super high strength gypsum prepared by FGD gypsum are investigated based on the test results of strength, thermal expansion rate, crystal appearance and size. The results indicate there is little difference of the properties of high strength gypsum prepared by FGD gypsum and natural gypsum. And furthermore, the FGD gypsum can be used as the good raw material of high strength gypsum preparation instead of natural gypsum.

Abstract: As a new environmental-friendly material and functional material, research and developmental utilization on bamboo charcoal has been taken much more attention. It described the basic properties of charcoal, such as composition, structure etc., and also introduced the adsorption properties, electromagnetic properties, far-infrared emission properties, release negative ions properties etc., as well as the corresponding application research status at home and abroad. The future research of bamboo charcoal should focus on the properties and application of micro nano bamboo charcoal.

Abstract: A new biomechanical model of articular cartilage was developed using ABAQUS to investigate the mechanical properties of different layers under different loading rates. It is found that the compressive strain of superficial layer is the largest, the compressive strain of deep layer is the smallest and the compressive strain of middle layer is between the superficial and deep layer under constant loading rate. The compressive strains of different layers increase with increasing loading rates. At the beginning of loading, fluid flows mainly in the superficial layer and flows into the middle and deep layer with the increasing time and the position of the maximum flow moves downward. Void ratio also increases with the loading time.

Abstract: As a viscoelastic and nonlinear connective tissue, articular cartilage bears continuous sliding load in the daily activities. The optimized digital image correlation (DIC) technique was applied to investigate the effect of sliding rate and compressive strain on the normal displacement of different layers in pig articular cartilage under sliding load. The normal displacements of different layers in cartilage increase gradually with sliding going on with given sliding rate and compressive strain. Experiments showed that the normal displacement of superficial layer is the largest, the normal displacement of deep layer is the smallest and the normal displacement of middle layer is between superficial layer and deep layer, and found that the normal displacements of different layers in cartilage increase with increasing compressive strains, but decrease with increasing sliding rates. The normal displacement of different layers are different under continuous sliding load.

Abstract: It is difficult to repair the damage cartilage by itself when cartilage is injured. Cartilage tissue engineering is an ideal treatment method to repair cartilage defects, but at present, the repair has some uncertain effects which is caused by the mechanical states of the repaired region. Under the compression, mechanical behaviors of the repaired full-thickness defect were analyzed by means of the digital correlation technology. Experiments show that in the direction of vertical cartilage surface, the maximum compressive strain of artificial cartilage is 1.7 times higher than the normal host cartilage at 5.1% compression, and it is 1.4 times higher than the normal host cartilage at 25.6% compression. In parallel to the cartilage surface direction, the interface appears compressive strain and the host cartilage near the interface presents a smaller tensile strain. In the aspect of shear strain, direction of shear strain at the junction changes to the opposite direction with the compressive increase.

Abstract: The Mg-4.0Zn-1.0Ca-0.6Zr alloy was prepared through casting-homogenizing-rolling and the study was made on the alloy microstructure as well as mechanical properties under different heat treatment processes. The result shows that, alloy sheets have their hardness and tensile strength rising at the first phase and inclining later with the extension of aging time, in which the maximum values gained at 12h i.e. 71.2HV and 320MPa accordingly. At 8h of aging the extensibility obtained maximum value of 19.2%, then the value reduced gradually with the continuous aging time. The mechanical properties of alloy sheets increased after tempering process, the reason should be that, inside of the crystal particles rich amount of Mg₆Ca₂Zn₃ and MgZn strengthening phases were separated out.

Abstract: To modifying cellulose through an eco-friendly process, an in-situ chemical blend modification of microcrystalline cellulose with PEG2000 was conducted by using co-rotating twin-screw extruder through a reactive extrusion process in the presence of IL namely, 1-N-butyl-3-methylimidazolium chloride which, was acting as plasticizer and solvent for cellulose . The modified cellulose (cellulose/PEG) was characterized by polarization optical images (POM), FT-IR, XRD and thermogravimetric analysis. The POM and XRD confirmed that cellulose I was changed into cellulose II. The FTIR and X-ray scattering showed that the cellulose hydrogen bond was disturbed through the extrusion, and strong interactions occurred between cellulose molecules and PEG which improved the thermal stability and decreased the degree of crystallinity.

Abstract: Surface response optimization of microwave-assisted extraction (MAE) conditions of anthocyanins from black soybean hull with the factors of ethanol concentration, microwave power, extraction time, solid/liquid ratio (g:mL) on the yield of anthocyanin were studied. The results showed that ethanol concentration and ratio of liquid to solid had most important influence; the interaction of ethanol concentration and ratio of liquid to solid,interaction of microwave power and extraction time had significant influence on extraction anthocyanins from black soybean hull. The optimum extracting conditions of anthocyanin from black soybean hull were as follows: adding 1:40.00 (m:v) of 60.35% alcohol (pH2.0) and extracting for 74.26 s under the power of 237.86 W.

Abstract: The nitrogen and phosphate were regarded as the target pollutants in this paper to study the balance of adsorption / desorption to nitrogen and phosphate, the adsorption dynamic characteristics under the action of four kinds of urban rivers and lakes sediments in Beijing as well as the impact of DOM in reclaimed water to absorb nitrogen and phosphate. Results show that: the processes of sorption of nitrogen and phosphate in the four sediments could be described by the Linear and Freundlich models, while the adsorption-desorption goes with hysteresis effect. The adsorption of nitrogen and phosphate were inhibited by DOM in reclaimed water, with an adsorption coefficient K_d decreasing by 0.04% -56.88%, reaching a significant level (confidence level α = 0.05);And DOM increased the nonlinear parameter 1/n, up to 2.20 times at most, resulting in a lower adsorption stable.