Advanced Materials Research Vol. 502

Abstract: The In_1-xGa_xN electronic structure is calculated by First principle based on density functional theory. The energy band structures and density of state is calculated. It can be found that the hybridization of the Ga4s4p and N2p，In5s5p is stronger than that of N2p，In5s5p in the undoped system. And it leads to the valence band moving towards to low energy level and the conduction band moving to the high energy level. Correspondingly, we can find a larger band gap than that of undoped InN. In conclusion, the wide band gap lead to the blue shift and Moss-Burstein effect occurs near the top valence band.

Abstract: Brake chamber shell is an important part in brake system, and it is produced by twice deep drawing process. This paper adopts the DYNAFORM software, simulate drawing process of brake chamber shell by using FEM method, and make a comparison with the actual production. The result shows that there is a high consistency between the simulation results and semifinished products produced by twice deep drawing process, meanwhile, analysis results of Dynaform sheet forming are accurate with high reliability.

Abstract: It is known that acceptor-carbon complexes have ionization energies less than those of the corresponding substitutional, separate acceptors in silicon. We present the formation mechanism for a shallower acceptor energy level called an X level that is due to an indium- carbon pair. Ab initio calculation methods were used to evaluate electronic structures and lattice relaxations of silicon with indium, carbon or a carbon-indium dimer. The results shows that the bonding interaction between the 5p orbitals of the indium atom and the 3sp orbitals of the silicon atoms bound with the indium atom mainly determines the ionization energy of the X level, and the ionic bonding interaction of the carbon atomic orbitals with the indium atomic orbitals in the X level enables the bonding interaction of the orbitals between the indium atom and the silicon atom to lower the corresponding indium acceptor level, and then to form the shallower X level.

Abstract: Based on the silk fabric specifications database, the paper proposes two technological parameters of selvage tightness coefficient and selvage warp density coefficient, and realizes the quantitative relationship of corresponding parameters between selvage and fabric. By making use of thousands data of silk products in the silk fabric specifications database, corresponding programs are wrote to achieve the automated numeration of various selvage parameters .Then the paper discusses three typical silk fabrics which contains eleven subclasses and analyses the distribution of the two parameters, with the comparison of selvage parameters in sub-categories of the same categories. The conclusion can provide a theoretical basis for the silk fabric design and production.

Abstract: Novel mace-like (wolf-teeth clubs) CdS nanostructures were successfully prepared on a large scale using CdCl2•2.5H2O and NH2CSNH2 as starting materials through a convenient mixed-solvothermal route. The as-synthesized products were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and UV-visible absorption spectroscopy. The experimental results reveal that the morphology of CdS products was greatly affected by the volume ratio of anhydrous ethanol and distilled water. The possible mechanism for the formation of mace-like CdS nanostructures is simply discussed.

Abstract: In this paper, the low-velocity impact properties of the 3D woven composites were tested. Through the study on the relationship of absorbed energy and material structure, the impact resistance of the composites has been discussed. The research results show that the low-velocity impact resistance of quasi-orthogonal composites is the best, the low-velocity impact resistance of orthogonal composites is the worst and angle tangled of interlayer joint composites stand somewhere between the two. Adding quasi-orthogonal unit into the structure, the low-velocity impact property of the composites can be enhanced efficiently. On the other hand, if the unit distribution of the enforced fabric is changed, the break time and break point will be changed. But the effect on the total absorbed energy is not obvious.

Abstract: Electrodeionization (EDI) is being applied more and more to treat wastewater containing heavy metal ions, especially for electroplating rinsing wastewater. The effects of feed water conditions including concentration, pH and temperature on the performance of EDI process for removal of Ni2+ from dilute synthetic wastewater were investigated systematically in this paper. It was found that the dilute resistivity of the EDI module descended from 1.5-2.8MΩ•cm to 0.36-0.45MΩ•cm while the influent Ni2+ concentration increased from 45 mg•L^-1 to 63mg•L^-1. Existence of some H+ in feed water would push the stack current up. An increase in temperature of feed water would facilitate the ion exchange and diffusion and thus promote mass transfer. It was indicated that feed water conditions had a significant effect on separation performance of EDI process for treating dilute solutions containing heavy metal ions. Pure water production could be accomplished and water reuse could be realized via EDI technology by appropriately restricting feed water conditions.

Abstract: Aiming at the source and corrosiveness of carbon dioxide, the in-situ carbon dioxide generation technology to enhance oil recovery was proposed。This paper presents the in-situ carbon dioxide generation technology mechanism, the expansion, viscosity reduction; oil-displacement efficiency and foamy oil of this technology were experimentally evaluated by using microscopic models and physical models. The experimental results indicated that the in-situ carbon dioxide generation technology could be used to produce enough carbon dioxide and get good efficiencies of oil expansion, reduction of viscosity and enhancement of oil displacement. Under the conditions of 2010mPa•s in oil viscosity, 60°C and 10MPa, the volume of oil could be expanded by25%, and the viscosity of oil can reduced to 52.7% , and the CO2 can displacement，restraining viscous fingering and changing liquid flow direction and carrying the residual oil.

Abstract: the hardening curve of the steel in the plastic deformation only considers the influence of the deformation degree on the resistance. This paper, according to the basic theory of plastic processing, proposes out the respective relation between the deformation resistance and the deformation degree, the temperature, as well as the rate. This paper gets the curves of these relations by experiments, summarizes the fundamental equations by simulation and finally deduces the plastic conditional equations relating to the material performance----the tensile strength.

Abstract: Artificial neural network (ANN) is self-adaptability, fault toleration and fuzziness. It is suitable to solve the seismic properties of high strength reinforced concrete columns with concrete filled steel tube core (HRCCFT). A three-layer back-propagation network model is build up to study the seismic properties of HRCCFT. The model is trained according to 30 sets of experimental data. The network convergence is fast. The model is verified by 8 groups of experimental data, the results show the predicted values of displacement ductility are in good agreement with test values. The precision of model is better than that of formula from other reference. This method is good enough to be used as an auxiliary method for structure design.