Advanced Materials Research Vols. 774-776

Abstract: The continuous separation of high concentration Cr (III) and Cr (VI) from strong acidic aqueous solution was achieved in column packed with strong alkaline anion exchange fiber (SAAEF). The optimal operation conditions are as follows: flow rate 5.0 BV· h^-1 and room temperature. The absorbed Cr (VI) on column could be recycled as Na₂Cr₂O₇ or K₂Cr₂O₇ solution after separation from Cr (III), using saturated NaCl+2.0% NaOH or saturated KCl+2.0% KOH.

Abstract: The development of new water pollution control technology, particularly the development of high efficiency and low cost adsorbents is imperative. A compound adsorbent was prepared with the combination of chitosan and bentonite. Bentonite was added in chitosan slurry of 95% the degree of deacetylation to prepare adsorbent which mass ratio is 1:5. Its absorptivity toward Cu²⁺ was studied. The results show: the dosage of the adsorbent is 14 g/L,the mass concentration of Cu²⁺ in wastewater does not exceed 180 mg/L,the pH value range from 6 to7,the adsorption equilibrium time is about 9 h and Cu²⁺ removal efficiency is over 97%.The low cost of adsorbents can be used to control industrial waste water containing copper.

Abstract: Numerical simulation on two-phase combustion characteristic in afterburning chamber of solid rocket ramjet was carried out by applying particle trajectory model. It was analyzed that the nozzle number of secondary combustion chamber, inlet angle of air and particles diameter impact on efficiency of combustion. Results show that the combustion efficiency in the afterburning chamber is highest, achieving 99.6% when the angle between both air inlets is 180°, particle diameter is 15μm, and 5-hole nozzle is used. By contrary, when the angle between both air inlets is 90°, particle diameter is 5μm, and 5-hole nozzle is used, the afterburning chamber has a lowest combustion efficiency of 70.3%.

Abstract: The SCR catalysts were produced with V₂O₅, WO₃, MoO₃ and anatase type TiO₂. The catalyst samples were ground and sieved for 0.3~0.6mm.The NO catalytic efficiency, selectivity against N₂O of the catalysts were investigated on a fixed bed reactor under simulated exhaust gas with a typical gas composition. The addition of W enhanced the catalytic efficiency of V(1)-W(x)-Mo (4.5)/TiO₂ catalysts at high temperature region, while lessened that at low temperature. Increasing the loading of W from 1.5% w/w to 4.5% w/w advanced the maximum catalytic efficiency from 88% to 99% and enlarged the temperature window of the catalyst. The presence of W promoted the N₂O generation. The V(1)-W(4.5)-Mo (4.5)/TiO₂ catalyst showed higher catalytic selectivity for NO compared to the catalysts loading W.

Abstract: This paper reported that, using the method of double layer composite successfully prepared high performance of electromagnetic wave absorption materials. Such a composite is composed of a cement matching layer filled with expanded polystyrene (EPS) beads and an absorbing cement layer made of EPS beads and carbon black. The samples were tested by arching method in the frequency range of 8~18GHz. The reflectivities were revealed to be excellent, the lowest being-17dB. The new material can be used for building indoor electromagnetic radiation protection.

Abstract: A bulk-heterjunction hybrid solar cell based on CdS nanorods as electron acceptor and conjugated polymers P3HT (Poly (3-Hexylthiophene)) as donor was fabricated through solution processing. Plasmon-active silver nanoparticle layers were introduced in the hybrid solar cell. Silver nanoparticle layers were fabricated using thermal evaporation deposition of 10 nm of silver thin layers on indium tin oxide (ITO) substrate followed by annealing. Under the surface plasmon excitation in Ag nanoparticles deposited on a semiconductor surface, increasing optical electrical field inside the photoactive layer led to an increased short circuit current density (Jsc) and improved fill factor (FF) of the cell. Consequently, under AM1.5G illumination (100 mW.cm^-2), the plasmon-decorated cell based on CdS-nanorods/P3HT showed a four-times increase of the power conversion efficiency (PCE) compared with the undecorated one.

Abstract: Nuclear quadrupole resonance (NQR) is a newly developed branch of radio frequency (RF) spectroscopic technique, allowing the detection of many substances containing quadrupole nuclei, such as ¹⁴N and ³⁵Cl, widely existing in explosives and narcotics respectively. In this paper, we focus on the research of its detection mechanism for ¹⁴N in urea and thiourea. Based on the Density Functional Theory (DFT), employing Beckes three-parameter hybrid functional combined with Lee-Yang-Parr correlation functional (B3LYP), with 6-311++G(d,p) basis set, we have obtained the quantum chemical calculations by using Gaussian 09. Furthermore, experimental results and some discussions related are also presented. At last, we find that the absolute values of relative errors of NQR frequencies are all less than 2%, which indicates that this study is reasonable.

Abstract: Samples composed of soft and hard magnetic alloys were tailored by two steps annealing the same Fe-based amorphous wires. Then the measurements of hysteresis μ₀M loop have been performed upon the samples. The evolutions of loops with the fraction of hard magnetic phase and the measured magnetic field indicated the existence of dipolar interaction between the two phases.

Abstract: The nature of doping acid play important role on the stability of conductive polyaniline (PANI). Many recent investigations have focused on different organic acids. Most organic acids are expensive and difficult to synthesize. According to industrial application, it is important to quantify the stability of conductive polyaniline doped with common acids. Herein, three common industrial acids (hydrochloric acid (HCl), sulfuric acid (SA), methanesulfonic acid (MSA)) doped conductive polyaniline was reported. The degradation performance of polyaniline was investigated by XRD and thermogravimetric analysis (TGA). The mechanism of degradation of PANI was discussed. The result indicated that the stability of PANI-HCl was better than that of other two samples. The optimization processing temperature of PANI-HCl is 100°C~150°C.

Abstract: Artificial ground freezing is a time-varying dynamic and complex process. Traits of the frozen soil wall are influenced by the refrigeration system operating conditions, geological conditions, boundary cooling, construction conditions and many other factors. Nature of the frozen soil and the structural state of the frozen soil wall is a function of temperature, yet the temperature field of the frozen soil wall is changing with time. Further, it has a bad influence on the buildings nearby when Frost-heaving and Thawing-settlement happened during freezing process. it will be necessary to comprehend their real-time settlement and deformation as well as to keep sure the frozen soil wall and the buildings nearby are on regular service. The Lindong mine wellbore is located in the Cretaceous Stratum. A information technology of freezing construction method is used to ensure the safe and efficient construction of the wellbore. It made a great contribution to the lingdong mine yielding and other similar projects.