Advanced Materials Research Vols. 466-467

Abstract: A cationic polyacrylamide-grafted starch (St-g-CPAM) flocculant for the coal slurry wastewater, was prepared by using corn starch and acrylamide (AM) as monomers, ethylene methyl propenoyl trimethylammonium chloride (DMC) as cationic monomer through solution polymerization. The effects of initiator concentration, reaction temperature, and monomer concentration on percentage of grafting and the grafting efficiency were investigated. The results show that the optimal conditions of the polymerization are as follows: the monomer to substrate ratio of 2.5, AM:DMC ratio of 2:1, potassium persulfate of 3×10-3 mol/L, reaction time of 4h, the reaction temperature of 50°C. The additional dosage of St-g-CPAM is varying between 20 and 30 mg/L to obtain good flocculation capability

Abstract: A new heterogeneous catalyst Fe-Mn/GAC (iron and manganese were loaded into activated carbon particles) was prepared, which had a better catalytic reactivity to decompose H₂O₂ compared with Fe/GAC and Mn/GAC. The removal rate of Orange IV increased more than 10% with this catalyst compared with Fe/GAC and Mn/GAC. The effect of the initial concentration of H₂O₂, the initial dye concentration, the initial catalyst concentration, the initial pH and temperature on the reaction rate constant were also studied. The activated energy for Fe-Mn/GAC catalyzed oxidation of the dye was determined to be 66.16KJ/mol. Reuse of catalyst did not decrease the removal rate of Orange IV. The tert-butanol experiment indicated that there were not only hydroxyl radicals but also other active species in the system.

Abstract: A novel cheap macromolecular intumescent flame retardants (Zn-MIFR), was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus-silicon characterized by IR. Epoxy resins (EP) were modified with Zn-MIFR to get the flame retardant EP, whose flammability and burning behavior were characterized by UL 94, limiting oxygen index (LOI), dilatation, char yield, smoke density rating (SDR) and maximum smoke density (MSD). The epoxy resins were obtained for the UL 94 V-0 rating at low Zn contents of 3.0 % get a LOI of 27.5% and char yield of 20.5%. Dilatation, SDR and MSD of EP/Zn-MIFR decreased. The degradation behavior of the EP/Zn-MIFR was studied by TG and EDX analysis. The experimental results exhibited that the initial decomposition temperature (IDT) was decreased, integral procedure decomposition temperature (IPDT) and amounts of Zn and P at the residue were increased.

Abstract: A series of liquid crystalline (LC) polysiloxanes (PI-PV) were prepared by use of poly(methylhydrogeno)siloxane and two kinds of terminal olefinic monomers. The chemical structures and liquid-crystalline properties of the synthesized materials were characterized by various experimental techniques. From PI to PV, the glass transition temperature and the isotropic temperature decreased slightly with increase of terminal fluoromethyl units in the polymer systems. All the monomers and polymers showed nematic phase with wide mesophase temperature ranges. The polymers PI, PII and PIII displayed single nematic mesophase, but PIV and PV bearing more terminal fluoromethyl units showed another smectic mesophase besides nematic mesophase.

Abstract: The physical structure and chemical properties of coating layer have an important influence on transferring and setting of the printing ink. In this study, the effect of pigment on coating layer structure and surface properties was investigated. The surface topography was explored using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The findings indicated that the pigment affected the pore size, depth and distribution of the coated paper surface. The conclusions were drawn that coating could improve coating surface topography and calcium carbonate pigment compared with kaolin pigment was not good to the paper surface properties, which resulted in high roughness, low paper gloss, high ink absorption and low paper surface efficiency.

Abstract: Soft rock roadway is one challenge of roadway support. With plastic state, it has a certain bearing strength, and its large plastic performance must release out in some form. Therefore soft rock roadway is not a single support effective, it must use a joint way. By numerical simulation, this paper analyzes uniform diffusion of bolt mesh support to wall rock stress, which provides a theoretical basis for bolt mesh support of soft rock.

Abstract: Based on Wiener-Khinchin theorem and Fourier transform, the coherence functions and the relevant parameters of various spectrums can be obtained from the simulation program. Through the analysis on the coherence properties of different spectrums, we also acquire the influence on the spectrum coherence of its characteristic parameters, such as the centre wavelength and the width. For the broadband sources used in the IFOG, the paper provides an effective calculation approach to acquire the accurate coherence functions and coherence parameters, which can be further used to analyze and optimize the SFS spectrums.

Abstract: The electro-hydraulic proportional relief valve which will be used widely, has better stability and pollution resistance compared with the traditional nozzle flapper and the electro-hydraulic proportional reversing valve in the hoist constant deceleration braking system. The model of the G-π bridge electro-hydraulic proportional relief valve is built in this paper based on the simulation software-AMESim and the characteristic curves of the port pressure are plotted according to different step signals. The influence that the oil elastic modulus exerts to the dynamic characteristics of the valve is also studied in this paper, which provides data supports for the rational design of the valve structure and the hydraulic oil with certain elastic modulus. As the core component of the hoist constant deceleration, the electro-hydraulic proportional relief valve provides the theory basis for the next research of the constant deceleration.

Abstract: Compared to the probe based on conventional piezoelectric ceramic, the high-performance ultrasonic probe made from polymer composite materials is much better, which has characteristics such as high sensitivity, wide bandwidth and good directional. And probe’s thickness electromechanical coupling coefficient KT value is up to 68%, which means it can reduce the crosstalk effectively to the phased array probe. In industrial, due to its high bandwidth, it has obvious advantages when used in coarse-grained materials testing and high-precision thickness measurement. In the medical field, ultrasound will reflex significantly at the impurities or the interfaces, and produce the Doppler effect in the flow of blood. Based on the sound field distribution comparative study of polymer materials ultrasonic probe chip, this paper proposed some polymer new applications in ultrasonic testing field.

Abstract: The proposal of ARM-based online detecting system of storage battery was suggested for the need of precise control of the working voltage and temperature of base stations of China Mobile. In terms of hardware, ARM7-LPC2368 of NXP Semiconductor was chosen as the processor chip, and the online detecting system was constructed using three modules: information acquisition, kernel control and battery. As for software, our proposal adopted the top-down design philosophy and modularized designing method and also embedded uC/OS-II which significantly improved the utilization rate of CPU. At last, the system precisely met the requirements of the proposal by field tests at base station of China Mobile, thus, verified the feasibility of the proposal.