Advanced Materials Research Vols. 690-693

Abstract: By Monte Carlo method with EAM potentials, the specific heat of liquid Co₅₀Fe₅₀ and Co₄₈Fe₄₈Th₄ alloys at different temperatures are obtained. The effect of Th on the thermophysical parameters is examined. Over the temperature range from 1400 to 2000 K, the specific heat decreases from to Jmol^-1K^-1 after Th was added. It is the addition of Th element which has bigger atomic radius, larger atomic mass, and complex arrangement of extranuclear electron, leads to the reduced specific heat.

Abstract: Generally speaking, the oxide interface quality can be determined by the interface trap density (D_it) distribution. In this paper, the D_it quantity obtained from the Terman method, which it is assumed that the D_it is equal to zero at the beginning for simulating the D_it effect in ultra-thin oxide. However, the lateral non-uniformity charges have existed in the oxide layer, which maybe obtained an equivalent D_it density not equal to zero also producing an equivalent D_it value. And, such faked D_it will be resulted in an error in high frequency measurement. Fortunately, it can be solved by differentiating technique to obtain an accuracy D_it quantity.

Abstract: C/C composite material is widely used as the insulation material since its advantage is obvious compared with other materials. It is necessary to evaluate its ablation, especially when it used in the warhead. An ablation/erosion test system based on plasma is researched. All the parameters related to the plasma can be monitored by it to calculate the enthalpy. Two ablation tests of the C/C composite material are carried by this system. The ablation of the carbon fiber and the erosion of the particle are mainly analyzed by the measure of the ablation rate and the SEM photos.

Abstract: This paper discussed the fabrication of anodic aluminum oxide (AAO)/CaO core-shell membrane by anodization and sol-gel processes and evaluated the relationship between the Al2O3/CaO and CO2 by thermodynamic calculation. According to thermodynamic property that CaO can reacts with CO2 forming calcium carbonate (CaCO3) in a lower temperature ranges, CaCO3 can also be decomposed to CaO in a higher temperature ranges. Because the reversible reaction property that CaO can be a CO2 absorbent/ de-absorbent. We address that AAO based on core-shell nanotubes structure to achieve such a demand. The captured CO2 can further convert to fuel material of hydrocarbons.

Abstract: The cold loss is larger in oil and gas processing device with cold insulation structure of failture. The cold insulation effect of oil and gas processing device is evaluated and analised,that is great significative to decrease the energy loss on processing and transportation of oil and gas.In this paper, of oil and gas processing device which have the failure cold insulation structure is evaluated and transformed ,whose cold insulation effect is analyzed and compared between pre-and post transformation. The study results show that transformation of cold insulation structure of failture can lower the cold loss and electricity consumption; the economic benefit is best when the nitrile rubber material is used.

Abstract: In this paper, on-road CO, THC, NO_X, CO₂ gaseous emissions characteristics of china IV CNG bus were analyzed based on on-road vehicle emission test in the peak and non-peak hours of city traffic in Shanghai using a portable emission measurement system (PEMS). The experimental results reveal that: compared with the condition results in the non-peak hours, it (conditions in the peak hours) have lower average speed, longer idle time and shorter high speed time; the NO_X emission factor and rate in the peak hour reduced by 5.66% and 70.2%; the CO, HC, CO₂ emissions factors are increased by 47.2%, 32.6%, 20.8%, and the CO, HC, CO₂ emissions rates reduced by 1.94%, 26.5%, 48.7% respectively, compared with that in the non-peak hours; The CO, HC, NO_X, CO₂ emissions factors all decreased as bus speed increased, while they increased as bus acceleration increased; the gaseous emissions rates all increased as bus speed increased; both the emissions factors and emissions rates contributions are highest at accelerations, higher at cruise speeds, and the lowest at decelerations for non-idling buses; the emissions rates under the condition of idling is lowest; gaseous emissions contribution under the various operating conditions has displayed certain correlations with the percentage of the time for different operating conditions.

Abstract: An improved experimental method has been described to determine dynamic material properties under conditions approximating uniform one-dimensional tensile loading. A lateral efficiency loading is produced when the projectile, which is made of low-density material, impacts high-intensity target. The lateral efficiency loading technique is a convenient and effective technique to study the dynamic fracture and fragmentation properties of materials under high strain rate tensile loading.

Abstract: By means of developing new rock abrasiveness device and using quenching steel spiral simulation micro-bit, the experimental investigation on rock abrasiveness that simulating the actual drilling surroundings in petroleum engineering had been conducted. based on the data of micro-bit’s wear weight, which broke unit volume rock, of which experimental samples are made from more than 850 cores of seven main geological profiles in Shengli oilfield, rock abrasiveness is divided into eight grades with Sturges empirical formula. The bit type selection and the bit life prediction could be conducted with the upper experimental method.

Abstract: MAN Diesels 6S50MC-C disel is a two-stroke marine diesel engine. Preload of the exhaust valve component is applied in four bolts. The preload of bolts can improve the fatigue strength of the exhaust component. In addition, the bolt pretension ensure the sealing in the maximum firing pressure. Using of simulation method, the displacement and deformation of exhaust valve component are analyzed when the maximum firing pressure and preload are applied. By analysis of the deformation of the exhaust valve housing under different preload force, the deformation of exhaust valve housing increase with the increaseing of preload. The maximum total deformation is 0.40mm in the preload of 720KN. The maximum deformation occurs in the region near the bolt in the side of exhaust gas outlet. The deformation in the direction of Y-axis of exhaust valve housing is along the Y-axis opposite direction when the preload is greater than 540KN. This indicates that the exhaust valve seal well. The sealing and deformation of the exhaust valve component meets the desgin requirement.

Abstract: Because the failure behavior of the soil surrounding the Push-extend Multi-under-reamed Pile will be affected by the placed location of the bearing push-extend reamed, further, the bearing capacity of the Pile is affected, in the paper, through experimental study and theoretical analysis, it is qualitatively analyzed that the influence of the location of the bearing push-extend reamed for the bearing capacity of the Push-extend Multi-under-reamed Pile, the achievements of the paper will present the well theoretical basis for synthetically considering all of affecting factors in the design of the Push-extend Multi-under-reamed Pile.