Advanced Materials Research Vols. 393-395

Abstract: The sea cucumber (Stichopus japonicus) was continuously hydrolyzed by pepsin, trypsin to get sea cucumber peptides (SCP), and low molecular peptides (LSCP), MW < 3000 Da, were collected through an ultrafiltration membrane with a molecular weight cut-off of 3000 Da Two main fractions, LSCP-1 and LSCP-2 were obtained by one step gel filtration column chromatography. Furthermore, the antitumor activities, in vitro, of LSCP-1 and LSCP-2 fractions were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. LSCP-2 showed significantly antitumor activity against the SGC-7901 and MCF-7 cell lines, LSCP-1 showed significantly antitumor activity only against SGC-7901 cell line, and two fractions did not show activity against A549 cell line. Overall, this study indicated that LSCP posseses potential to treat gastric cancer and breast cancer.

Abstract: Forest fire is one of the most important ecological factors in the forest ecosystem. The Daxinanling forest region has not only the largest forest areas, but also the biggest forest fire burned area in China. By analyzing the recorded climate and forest fire data of Ta He forestry bureau from 1974 to 2004, the following results can be concluded: (1) There were 298 forest fires recorded by Ta He forestry bureau during 31 years and the burned area were 1.63 million hectares totally with 9.6 forest fires per year, unpredictable and short fire cycle as characters. (2) According to the occurrence time of forest fires, the Julian date concentrated between 102~181 and 240~293, corresponding April 12th to June 30th and August 28th to October 20th, which were spring and autumn fire prevention periods. Major fires mainly occurred in spring of 1974~1982, 1986~1987, 1993, and 1998~2002. The major fires cycle were 4 to 5 years. (3) The related indices of temperature, relative humidity, rainfall, and wind speed recorded in June in Ta He forestry bureau were 0.3929, 0.5274, 0.6136 and 0.1679. Temperature, relative humidity and rainfall factors in June had obvious linear relationships to forest fires, while the relationship between wind speed and forest fires is unobvious.

Abstract: Batch experiments were carried out to study the adsorption characteristics of Cu(II) onto Carboxymethylcellulose Sulfate(CMC-S). Previous studies had shown that Acidic/neutral pH was favorable to the adsorption of Cu(II). The Kinetic and thermodynamic analysis were performed in detail. Kinetic studies indicated that Cu(II) adsorption on CMC-S in the system followed the pseudo-second order kinetics. Moreover, the experimental equilibrium data was analyzed using the linearized form of Langmuir, and the Langmuir isotherm was found to provide the best theoretical correlation of the experimental data for the adsorption of Cu(II). The monolayer adsorption capacity was determined to be 127 mg of Cu(II) per gram of CMC-S at 25°C. Thermodynamic analysis showed that adsorption process obeys an exothermic path of the negative value of and spontaneous with negative value of .

Abstract: Silver powder and silver-tin oxide composite powder were synthesized by hydrothermal method. The powders were characterized by XRD and SEM. The results show that there are macroscopic appearance and microscopic structure differences between two kinds of powders. Silver powder is gray and spherical particles with 3μm diameter, and silver-tin oxide composite powder is black ash and mainly flake particles about 0.3μm in thickness. Silver crystal in silver tin-oxide composite powder is preferentially oriented in the (111) crystal plane and its oriented index is 2.581. However oriented index of silver crystal in silver powder is 1.048 which shows the crystal isn’t preferentially oriented in the (111) crystal plane. That crystal lattice parameter of silver crystal in silver tin oxide composite powder is 0.409 34 nm larger than 0.408 68 nm of silver powder. The mechanism analysis shows that the hydrogen bonds among Sn(OH)62- and Ag(SO3)23- complexes are inhere factor which result in the formation of flake silver tin-oxide composite powder.

Abstract: Microcapsules containing the mixture of styrene and epoxydiacrylate (St/E51-AA) for use in self-healing thermoplastic composites were synthesized by in-situ polymerization using melamine-formaldehyde (MF) as shell materials. The microcapsules were prepared in two consecutive steps, emulsification of St/E51-AA in water and then, encapsulation. The chemical structure of microcapsule was identified by Fourier transform infrared spectroscopy (FT-IR) and proton magnetic resonance spectroscopy (1H-NMR), respectively. Morphology and shell wall thickness of microcapsule were observed using scanning electron microscope (SEM). The effect of dispersion rates, through a limited range, was carefully examined on the particle size and core content of microcapsules. It was found that styrene/ epoxydiacrylate-loaded microcapsules were successfully prepared through the proposed technical route, and their mean diameters fell in the range of 36~110 μm. Both core content and microcapsule size can be adjusted by selecting different dispersion rates. The highest loading of St/E51-AA in the resultant microcapsules can be about 85%. In terms of thermogravimetric analysis (TGA), thermal behavior and storage stability of the capsules were studied.

Abstract: According to the coal mine underground work place humidity changes affect the measurement precision of dust concentration, improper spray cause coal with the water loss and wastes a lot of water resources, the paper put forward a correction factor of dust concentration based on the relative humidity, establish the relation model of concentration and humidity. The test results show that: the dust concentration correction factor and relationship model of concentration and humidity are effective and scientific, it has better practicability to solve the problem of underground coal mine.

Abstract: The N-doped Cu11O2 (VO4)6 photocatalyst was prepared using the sol-gel method. Techniques of X-ray diffraction (XRD), scanning electron microscope (SEM) have been employed to characterize the as-synthesized materials. During liquid phase photocatalytic degradation of Methy lorange(MO) under the UV-light, the as-prepared N-doped Cu11O2 (VO4)6 exhibits higher activity than the pure Cu11O2 (VO4)6 without doped N. It found that the N-doped Cu11O2 (VO4)6 prepared with the molar ratio of citric acid to metal inons be 2:1, N/Cu molar ratio of 12%, pH=7 and calcinated under 500°C for 4 hours was pure triclinic phase. In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 94.42% or so in 60min under 20W ultraviolet lamp.

Abstract: The five plate numbers were peak plate number (q’), slip-mechanism plate number (q), theoretical plate number (n0), real plate number (n) and plate-model plate number (q0). Slip mechanism was introduced into plate model and then a new equation of elution curve was deduced. The relational expression of five plate numbers was deduced through the new equation. Peak plate number and slip-mechanism plate number were new plate numbers derived from slip mechanism, and the physical pictures of them was discussed. Peak plate number would be regarded as an asymmetry index of peak, as column plate number is regarded as an efficiency index of column.

Abstract: This paper is concerned with a mathematical model for simulating hydrodynamics of 2D flood flows with the WENO scheme and the Finite Volume Method on unstructured grid. The time discretization uses the Runge-Kutta TVD scheme. By using the proposed model, we calculated the flow property of dam-break, and obtained the flow velocity field distributions. The calculated results show that the WENO scheme has higher accuracy and better stability, and has the ability to automatically capture shock waves, and may suppress the oscillations of numerical solution. This model can effectively simulate the hydrodynamics of 2D river flow with irregular boundaries.

Abstract: A numerical simulation study of the hydrodynamics of oxidation ditch is presented. The numerical method is based on a pressure-correction algorithm of the SIMPLE-type. A multigrid technique based on the full approximation storage (FAS) scheme is employed to accelerate the numerical convergence, while as a turbulence model the RNG κ-ε model with wall functions is used. The numerical results for velocity, as well as for the pressure distribution in the oxidation ditch are obtained．