Advanced Materials Research Vols. 201-203

Abstract: This paper discusses characteristics of supersonic projectile shock wave in muzzle regions when firing high explosive anti-tank (HEAT) and high explosive (HE) projectiles. They are fired with a muzzle velocity of Mach 3.5 at horizontal from a medium caliber tank gun equipped with a new designed multi-perforated muzzle brake and of Mach 2 at elevation angles from a large caliber howitzer also equipped with a new double baffles muzzle brake, respectively. In the near field, pressure signatures of the N-wave generated from projectiles are measured by cotton sheathed 32-microphone ring array. Recordings measured from the microphone array are used to demonstrate several key characteristics of the shock wave of supersonic projectile. All measurements in this study can be a significant reference for developing guns, tanks or the chassis of fighting vehicles.

Abstract: The application of AE measurement for condition monitoring of the slow-speed and heavy-load equipment is gaining ground. However, different AE features are sensitive to fault in varying degrees when they are employed in the trend analysis. Therefore, in this paper the focus is on the selection of the appropriate AE features for the trend analysis. First the AE features are ranked by Laplacian Score method according to their importance, and then a new feature index is obtained by the fusion of the features with their ranking scores, which serve as weight coefficient in this condition. The degradation data of the bearings in the belt conveyor are used to prove that the proposed method is effective.

Abstract: This work was to reduce the epoxidation time of soybean oil with the assistance of ultrasonic irradiation and a kind of fatty acid as the catalyst in the presence of formic acid as the carrier of reactive oxygen. The operational parameters affecting the epoxy value of soybean oil, such as the amount of fatty acid and the ultrasonic frequency, ultrasonic power and reaction time were studied. And the interfacial tension of the aqueous-oil phase was decreased with the catalyst fatty acid adding or the assistance of ultrasonic irradiation, therefore the reaction rate could be accelerated. The maximum epoxy value of epoxidized soybean oil was 17.19% increased compared with the epoxy value that treated by non-ultrasound assistance in the same reaction time. Experimental results indicated that the epoxy value could be enhanced under the ultrasonic irradiation assistance, where the reaction time could be effectively reduced.

Abstract: Through analyzing excess pore pressure dissipation datum measured by CPTU probe and pore pressure mini-transducers on CPTU model test, the consolidation coefficient of soil of CPTU model test has been computed. Based on axis-symmetric consolidation model and Terzaghi consolidation theory, the computing equation of soil horizontal consolidation coefficient on CPTU model test has been acquired; on CPTU model test 50% degree of consolidation has been applied as calculate standard to compute soil horizontal consolidation coefficient, and dissipating time of 50% degree of consolidation can be acquired by normalized excess pore pressure dissipation curves based on excess pore pressure dissipation datum; through a series of indoor consolidation tests, the consolidation coefficient of remolded soil of CPTU model test sampling by horizontal and vertical direction has been acquired, and the results show that vertical consolidation coefficient is about 1.6 times greater than horizontal consolidation coefficient on indoor consolidation test, and large difference between horizontal and vertical property of remolded clay soil on CPTU model test has been existed; compared with the value of two test methods, the value of horizontal consolidation coefficient acquired by CPTU model test is roughly 100 times greater than the value of horizontal consolidation coefficient acquired by indoor consolidation test. The achieved result can provide a foundation for further study for CPTU mechanism.

Abstract: According to the morphology of the single-nuclear cell, the eccentric-sphere (ES) model is proposed. The analytic expressions of amplitude function and phase function are revised base on the geometrical-optics approximation (GOA).The intensity distributing and phase distributing of the single-nuclear cell are also simulated by numerical calculation. The incident light orientation and the size of the nuclear on the impact of the backscattering have been discussed. After the analysis, we find that the model and the theory are much closer to the experimental fact compared with the single sphere model. These promote perfecting of the revised theory for inspection of real cell and provide a theory foundation for improving the measuring technique and identification technique of cells.

Abstract: Through the analysis for steel of 4145H drill collar, Research into the various factors of cutting, such as the cutting tool material, cutting-tool angle and cutting parameters, combined with the actual structure of the workpiece and the superlong deep-hole processing method for study. In the test, the machining process is analyzed, especially the process of boring and honing. The test result indicates that the trepanning process is stable and reliable to solve the superlong deep hole (Φ71mm×7500mm) of 4145H drill collar steel processing problems of production if the optimizing cutting method is appropriate and the cutting tools and the cutting parameters are rational.

Abstract: Through founding the mathematical model of heat and mass transfer, discussing quantitatively the temperature fields distribution in the case of body wearing cloth has an important significance in the lucubrate of garment thermal comfortability. Establishment of the 2D heat transfer model about upper arm is according to the characteristics of the arm’s heat and mass transfer. The distributing of temperature fields of upper arm transverse section under human wearing varying fabrics is accepted by using finite element analysis software ANSYS. This method can be extended to the whole body temperature fields. And the results have an important reference value for the study of garment thermal comfortability.

Abstract: Large scale of the industrial waste is not timely disposed of due to economic rapid development. It is the main reason why environmental pollution problem is getting more and more serious and we should monitor the pollution of industrial waste. A MODIS (Moderate Resolution Imaging Spectroradiometer) senor is used for long-time and dynamic environment monitor because it has advantages of high time resolution and high spectral resolution characteristics etc. SPOT satellite data is used to analyze the ground vegetation for its higher ground resolution and rich product data bases. The influence of industrial waste on environment is analyzed and the result of research is verifyed with the information of local meteorological agent and observation data of site. This method can be used for monitoring wide-range industrial waste and have good performance of monitoring and early warning industrial waste sites which are in mountainous area.

Abstract: A method of EIS measure-polarization-relaxation was used to investigate the corrosion performance of different hot-dip coating layers of galvanized steel. The result showed that the corrosion of hot dip galvanized steel was divided into four phases, and the corrosion of each phase was corresponded to different layer respectively. The anti-corrosion difference of every layer was very distinct. The optimal anti-corrosion layer of hot dip galvanized steel was δ phase. This method could be used to detect coating corrosion quickly.

Abstract: Pleurotus nebrodensis were packaged with PVC and PE with different thickness (0.03 mm and 0.05 mm) at 4°С. Package gas composition, respiration rate and relative electrolyte leakage were measured during storage at 4°С and 95%RH for 28 days. The results showed that auto modified atmosphere pattern would be formed at 7th day of the storage. The atmosphere concentration in the package of 0.05 mm films was 0.1~5% O₂ and 6%~10%CO₂ after 7days, then maintaining the atmosphere concentration stable in the following days of the storage test. Compared to the 0.03 mm film, the 0.05 mm film was more effective for decreasing respiration rate and electrolyte leakage of pleurotus nebrodensis to delay its senescence. It could be taken for granted that pleurotus nebrodensis was apt to storage in the circumstance of low O₂ and high CO₂.