Advanced Materials Research Vols. 156-157

Abstract: Based on the advantages and disadvantages of existing active protection system, this paper proposes a new type of airbag active protection system. The components and working process of the system is introduced. Then taking the physical process of airbag active protection system against a rocket projectile as an example, a 3D finite element model (FEM) of airbag and rocket projectile is set up. With the assistance of the software LS-DYNA3D, through performing the simulation when the rocket projectile touched the airbag with an angle 30° from the normal interface, the intercepting efficiency is calculated and analyzed in the simulation. Results show that airbag can deform and rupture the metal jet generated by the rocket projectile, thus greatly reduce its armor penetrating effect. Finally, it shows excellent protective effect of the airbag active protection system.

Abstract: Chinese jujube (Zizyphus jujuba M) fruit at the postharvest stage was easily have a dramatic decline in quality. The effect of 1-MCP and CaCl2 in delaying fruit ripening and improving storage quality was investigated through this study. Chinese jujube fruit were harvested and then treated with 1µL L-1 1-MCP for 24 h at 20°C, immersed in 1% CaCl2 solution for 10min and their combination, then kept 0 °C and 80–90% RH after treatment. Results indicated that 1-MCP and CaCl2 were effective in terms of senescence inhibition during storage and compared to control, and the performance of 1-MCP was little better. Fruit treated with 1-MCP and CaCl2 had ability to maintain firmness, soluble solid concentration (SSC), weightlessness, membrane permeability. The ethylene production rates of jujube fruit were effected significantly by treatment with 1-MCP, not affected by CaCl2 treatment like control samples, however, they both had a visible influence on the content of MDA compared fruit with untreated. Furthermore, treatment with 1-MCP + CaCl2 resulted in additive beneficial effects on ripening inhibition of the fruit and maintaining the qulity of Chinese jujube fruit.

Abstract: Taking pleurotus nebrodensis as a test material to research the pleurotus nebrodensis preservation effect with using modified atmosphere packaging of PE with different thickness at 4 , evaluating the quality changing during the storage life. The results showed that 0.05mmPE treatment has the best preservation effect, which could effectively maintain the storage circumstance of low O2 and high CO2 concentration, decreasing the weight loss and postpone the reducing of luminosity L and browning time. Besides, using modified atmosphere packaging of 0.05mmPE can postpone the decline of quality of pleurotus nebrodensis, enhancing the storage quality and prolonging the life of postharvest storage as well.

Abstract: Low-cost adsorbent which was burned rice husk was used in this study. The burned rice was tested with a series of packed bed in plastic bottle. The flow rate was controlled at 0.1 ml/s for all the experiment. Thomas model was used to predict the breakthrough time and all experiments were carried out at room temperature. The results indicated that the burned rice husk has a potential to be low-cost adsorbent for removal of red acid dye

Abstract: Based on the geological configuration and formation lithology of igneous rock stratum of Santanghu, optimized design methods of PDC (polycrystalline diamond compact) bit are used to design PDC bit crown shape, cutting angle, the distribution of cutters and hydraulic structure, etc. Especially, these methods, which are design methods of gentle crown profile, spiral blade, high-density distribution of cutters, suitable back rake angle, and hydraulic structures which are more flexible nozzles of asymmetric arrangement and deeper fluid course layout, are fit for high hardness, multiple interbed and high abrasiveness of the igneous rock formation. The bit designed in this paper has turned out to be much better in the experiment of Horse 36 well of Santanghu.

Abstract: Many material have different stress-strain relation in tension and compression, generally the relation is nonlinear. In this paper, we use two exponential functions to approximately represent the stress-strain relation of nonlinearly elastic material and analyze strength-difference structure of bars jointed to Rigid-body of fixed-point motion. The displacement method is used to derive the universal expression of calculating stress and strain. The nonlinear equations for computing angular displacement of the rigid-body has been given and general computing program has been worked out. They can be accurately and conveniently calculated. This problem has been solved satisfactorily.

Abstract: A theoretical model was developed to describe the bending behaviour and property of nonwovens with two-dimensional structure. The bending and tensional behaviours of single fibre with and without slippage in a bent fabric were analyzed. The method determining the neutral plane of bent nonwovens and the bending rigidity of fabrics with general two-dimensional structure were developed, incorporating fibre orientation distribution, number of fibres, fibre original position before bending and the Poisson’s ratio of the fabric. The analyses also give the fibre orientations that lead to the maximum and minimum contributions to the bending rigidity of the nonwovens in laminate and sandwich structures

Abstract: Maintaining good surface quality usually involves additional manufacturing cost or loss of productivity. The Taguchi design is an efficient and effective experimental method in which a response variable can be optimized, given various control and noise factors, using fewer resources than a factorial design. This study included feed rate, spindle speed and depth of cut as control factors, and the noise factors were the operating chamber temperature and the usage of different tool inserts in the same specification. An orthogonal array of L9 (34) was used and the optimal cutting combination was determined by seeking the best surface roughness (response) and signal-to-noise ratio.

Abstract: As the core of automotive welding production line, the development speed and quality of automotive welding jig impact on the automobile production cycle and manufacturing precision directly. At present, the traditional design method of automotive welding jig is difficult to adapt to the developing speed of auto body. In order to improve the design efficiency of the welding jig, a rapid automobile welding jig design method based on parametric technology is developed in this paper. Supported by parametric theory, combining with CATIA secondary development approach, the principle and structure of the automobile welding jig rapid design system are presented, and related key technologies in rapid design system developing are studied deeply, and a rapid welding jig parametric design system is developed finally. Taking one station of rear side member for example, the generation process of automotive welding jig is analyzed in detail, and design practice shows: the welding jig designed by this system has shorter development cycle then the traditional method.

Abstract: A universal transit heat transport equation was represented and all parameters for applying such a formula to drying of Radiata pine were modeled, incorporating reasonable physical conditions. In previous empirical models, the influence of drying temperature on the conviction heat transfer was ignored, though it is parentally not negligible. In this study, a multivariate regression model was developed from previous experimental data, in which both air velocity and drying temperature were taken into consideration. In addition, the models of heat diffusion properties in axial, tangential and radial directions were presented in which drying conditions and wood properties were taken into account. With those models, scenario computer simulation may be conducted to explore the drying phenomena of Radiata pine board.