Advanced Materials Research Vols. 989-994

Abstract: In this paper, the NOx emission of original diesel engine and the urea supply model of SCR system under different working conditions of ESC were obtained according the requirement of GB17691-2005[1]. Then the model of urea demand was established, and the comparison was made with the actual urea supply. In addition, the causes of the differences between them were analyzed.

Abstract: The effect of sodium methylacrysulfonate (SMAS) upon the molecular weight, molecular weight distribution and polycarboxylate (PCE)’s dispersion and dispersion-retaining ability were investigated by Gel permeation chromatography (GPC) and test of the fluidity of cement pastes. The results showed that the dosage of SMAS was inversely proportional to the molecular weight of polycarboxylate, and a cubic equation relationship existed between the molecular weight of the polycarboxylate and the reciprocal of SMAS dosage. There was an optimum middle dosage of sodium methylacrysulfonate which could control the molecular weight polycarboxylate, and then affect its dispersion and dispersion maintain performance. The effect of sodium methylacrysulfonate on the monomer conversion rate was also systematically discussed by means of high performance liquid chromatography (HPLC).

Abstract: In order to study the effect of the pH value of reaction system on the properties of polycarboxylate-based superplasticizers (PC) and on the cement workability, the PC are synthesized in different pH environments from 3 to 11 at room temperature. The results show the water-reducing performance of PC can be tuned by controlling the pH value of reaction system at room temperature, which affects not only the efficiency and rate of redox initiator systems but also the reactivity of active monomers.

Abstract: Pluronic F87/Poly (lactic acid) block copolymer (PLA-F87-PLA) was synthesized by bulk polymerization. Paclitaxel-loaded PLA-F87-PLA nanoparcticles were prepared by a dialysis method. The loading efficiency was determined by UV. The results showed that the loading efficiency of paclitaxel for PLA-F87-PLA nanoparticles was 69%. In vitro release behavior of paclitaxel-loaded PLA-F87-PLA nanoparticles was studied by HPLC. In vitro release behavior showed an initial rapid release followed by a slow release. The biocompatibility of nanoparticles was measured by MTT. The viability of paclitaxel-loaded PLA-F87-PLA nanoparticles was less than that of free paclitaxel. The results indicated that PLA-F87-PLA copolymer has good biocompatibility.

Abstract: Because of the poor quality of the operational water (urban reclaimed water) of one power plant in Hebei, China, a high-efficiency reverse osmosis (HERO) system with foreign patents is utilized for advanced treatment of the reclaimed water. The influence of the main factors (including the alkalinity and the suspended solid content of the feed water, the flux, and the pH of the concentrated water) on the performance of the HERO system were studied. The high alkalinity (high concentration of carbonate) of the feed water resulted in HERO scaling, and the low alkalinity caused the penetration of hardness through the weak acid ion exchangers and, therefore, also caused HERO scaling. The high suspended solid content of the feed water caused rapid decrease in the product flux of HERO. The low concentrated water flux also decreased the product flux. As the pH of the concentrated water became higher, the stability of the HERO operation increased. Based on the pH endurance of the membranes and the characteristic of the high-pH operation of the HERO system, the water production was basically stable when the pH of the concentrated water lay between 10.5 and 10.8. Affected by the ammonia in the reclaimed water, the pH of the product water was higher than that of the feed water. The pH of the feed water was higher than that of the concentrated water. When the pH of the concentrated water was above 10.8, the pH values were close to one another. The results of the chemical cleaning experiments indicated that hardness, phosphorus, ammonia, silicon dioxide, and iron ions were the main influencing chemical factors of HERO, in which the former three formed a sediment of magnesium ammonium phosphate, and the latter two formed an iron silicate sediment.

Abstract: The paper introduces an experimental process on measurement of ultra low sulfur in IN718 by using infrared carbon sulfur analyzer. The experimental data shows that, infrared absorption method can be used to analyze and measure the ultra low sulfur in IN718, and the precision and accuracy of this method meets the requirement of ASTM E l019-2000. It can be concluded that it is a feasible method in practice.

Abstract: Polyphenylene vinylene derivatives with various alkoxy branched chains, including PMOBOPV,PMOCOPV,iso-PMOCOPV and PMODOPV,were synthesized via a dehydrochlorination route,and characterized by FTIR,HNMR,DSC,TGA,UV-Visible and fluorescence spectroscopy. The result indicated that as-prepared polymers were of remarkable thermal stability and solubility in common solvent with the maximum UV absorption peak at ~492nm and light emission at ~555 nm.

Abstract: The graphene oxides were prepared form graphite by thermal expansion and ultrasonic dispersion. The structure of graphene oxides was characterized by Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD) and Raman spectra. The difference of structure of graphene oxides by two preparation methods was compared. The measurement of FTIR and XRD showed the graphite was completely oxidized. The graphene oxide prepared by thermal expansion would lose large number of active functional groups, such as hydroxyl, carboxyl group, et al. However, the graphene oxide prepared by ultrasonic dispersion can retain these active functional groups. These active functional groups will be benefit to chemically modify the graphene oxides and prepare the polymer/graphene nanocomposites.

Abstract: . The micro-Raman technique is used to examine the phase purity of Sr₂FeMoO₆ compound in this work. It is found that the Raman spectra of Sr₂FeMoO₆ compound without impurity consists of the peaks at about 440cm^-1 and 620cm^-1. The broad peak and shoulder at 820-890cm^-1 in the Raman spectra is assigned to the most common impurity SrMoO₄ and some other unidentified co-existing phases, which is approved by the results of X-ray diffraction.

Abstract: Sucrose char sulfonic acid (SCSA) efficiently catalyzed the one-pot, three-component Mannich reaction of ketones, aromatic aldehydes and different amines in ethanol at 30°C and afforded the corresponding β-amino carbonyl compounds in good to excellent yields . This method provides a novel and improved modification of the three-component Mannich reaction in terms of mild reaction conditions , clean reaction profiles and a simple workup procedure.