Advanced Materials Research Vol. 648

Abstract: The local equilibrium in the kinetic process of dissolution is addressed. The measured dissolution kinetic data of Ag on Cu(111) surface are well fitted by the modified Darken model. Using the obtained fitting parameters, the discontinuous transition of Ag surface concentration against the bulk concentration of the neighboring layers deduced from the local equilibrium model is quantitatively interpreted.

Abstract: Cutting steel is required to have high wear resistance with certain hardness and deformation resistance. The commonly used machinery material for meat processing in china is 4Cr13, which is far inferior to the imported German steel X80CrVMo13-2. After studying the influence of different heat treatment process on its wear resistance, we have come to the following conclusion: X80CrVMo13-2 steel, after quenched at 1050°C and tempered at 500°C, has an excellent wear resistance and 4Cr13 steel, after normalized at 1010°C and tempered at 500°C has a fairly good wear resistance.

Abstract: Low and easy brittle characteristics of lightweight aggregate concrete tensile strength, shear strength, combined with high strength lightweight concrete requirements in the selection select strength Lytag, silica fume, superplasticizer material, preparationhigh strength lightweight aggregate concrete. Experimental study on the water-cement ratio, coarse aggregate rate ratio factors on the strength of lightweight aggregate concrete.

Abstract: In this study, based on the test of the high strength materials of steel-encased concrete composite continuous beam, the ultimate flexural capacity of 8 composite continuous beams are analyzed by using the finite element analysis software ABAQUS. Numerical results show that it is a very good agreement for the load-deflection curves which obtained by finite element method (FEM) and those by the test results, and the error control is less than 8.5%. When selecting and utilizing appropriate cyclic constitutive model, element model and failure criterion of high strength steel and high strength concrete, the accuracy of the calculation can be improved better.

Abstract: Mn modified carbon sphere supported Pt catalyst was successfully prepared through a one-pot process. The modification of carbon sphere was operated in liquid phase reaction without any post-processing, and Pt was directly reduced to deposit on the composite support in the same suspension system. The role of Mn as a modifier can show change of adsorption state by XPS, XRD and electrochemical tests. At the same time, the improved the methanol electrooxidation performance, can be proved from lower adsorptive capacity and lower electrooxidation peak potential.

Abstract: Four groups of 1Cr17 stainless steel with diffirent wt% of boron ( 0ppm, 16ppm, 22ppm and 28ppm ) were smelted by a vacuum induction furnace. Then chemical immersion and electrochemical method (the tafel polarization curve method) were used to investigate their corrosion behavior at different temperature (25 °C, 40 °C) in HCL medium . The results show that after adding Boron elements of the 1Cr17 stainless steel sample, it is obvious that its resistance to general corrosion increases and the resistance to intergranular corrosion weakens; at different temperature (25°C, 40°C)in 10% hydrochloric acid solution medium the Corrosion kinetics law are different, while with B element content increases, the immersion corrosion rate decreases. in the reducing hydrochloric acid solution, sample with boron elements show a good behavior on corrosion resistance.

Abstract: A novel cheap macromolecular intumescent flame retardants (Mg-MIFR), was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus- magnesium characterized by IR. Epoxy resins (EP) were modified with Mg-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 Mg contents of 4.0% get a LOI of 27.0% and char yield of 19.8%. Dilatation, SDR and MSD of EP/Mg-MIFR decreased. The degradation behavior of the EP/Mg-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 Mg and P at the residue were increased.

Abstract: In this paper, aiming to apply Parashorea chinensis to engineering, its machining properties (including planning, sanding, drilling, shaping, mortising and crosscutting) compared with Toona sinensis, were tested. Their properties were tested according to the criteria ASTM D1666-87 and the test on crosscutting was referred to the method established by New Zealand Forest Research Institute. The results shown: the machining properties of Parashorea chinensis and Toona sinensis in the planning, sanding, shaping and crosscutting show excellent; the mortising properties of Parashorea chinensis and Toona sinensis are separately fair and good; in the machining performance comprehensive evaluation system of full marks 50 points, the comprehensive marks of Parashorea chinensis is 45.6 points, better than Toona sinensi 43.7 points, which shows that it is a kind of excellent wooden-products material for engineering and can be used to product high-grade furniture and so on.

Abstract: Reforming of methane is an important route to produce sygas. In this paper, recent progresses of noble metals (Rh, Ru, Ir, Pt, Pd) catalysts for methane reforming in material application engineering is reviewed. The discussion mainly focuses on catalytic performance of noble metal catalysts or noble metal promoted Ni catalysts in methane reforming reaction. Effects of noble metals, supports and preparation methods on the catalytic activity, selectivity, coke deposition and stability of catalysts have been briefly summarized. In conclusion, Rh as active component, Pd as material for membrane reactor, Pt or Rh as promoters for Ni catalysts, all gave high CH4 conversion, improving catalytic performance.

Abstract: This article used the grinding treatment as a physical modification method, and the effect of different grinding times on fluorgypsum was studied. Calcined alum, potassium sulfate, and sodium oxalate were selected as fluorgypsum chemical activators, and their effects on the fluorgypsum hydration process, strength, and hardened-body microscopic morphology were investigated, respectively. The results could be showed as follows: when the grinding time was 30min, the residue of fluorgypsum on 80 mesh sieve accounted for 6.8% and the water demand for normal consistency reached a minimum of 30%; three activators could accelerate fluorgypsum hydration process varying degrees.