The transient pressure waves in the Intake and exhaust systems directly affect the Intake and exhaust processes of diesel engines, thus further affecting the combustion process and the performance of diesel engines. The variation rules of the Intake and exhaust pressure waves at different engine speeds and loads in a high-pressure common-rail diesel engine were studied. Then, the effects of EGR rate and VNT nozzle opening on the Intake and exhaust pressure waves were systematically studied by bench test and one-dimensional simulation analysis. The results show that at 2000 r· min-1 full-load, when the EGR rate increases from 0 to 10%, the average Intake pressure and the average exhaust pressure both decrease. The fluctuation waveforms of the Intake pressure and the exhaust pressure change significantly. The fluctuation intensity of the Intake pressure decreases by 58. 6%, and the fluctuation intensity of the exhaust pressure increases by 77. 2%. As the EGR rate increases from 10% to 30%, the average Intake pressure and the average exhaust pressure both decrease. The fluctuation waveforms are basically unchanged. The increasing magnitudes of the Intake and exhaust pressure fluctuation intensities are 16. 6% and 20. 5%, respectively. As the VNT nozzle opening increases, the average Intake pressure and the average exhaust pressure both decrease. The corresponding phases of the Intake pressure wave crest and trough are delayed. The fluctuation waveforms of the Intake and exhaust pressure are basically unchanged, and the fluctuation intensities do not change significantly.

Shock waves are one of the primary damage parameters of an ammunition explosion. Therefore, accurately obtaining the shock wave pressure distribution law after ammunition explosion is greatly significant for the ammunition damage power evaluation and the guidance of ammunition selection in the operations course. This study established the mapping function between the surface reflected and free-field shock wave pressures, considering the altitude effect on shock wave pressure. Finite element numerical simulation analysis of typical (trinitrotoluene) TNT explosive quality and static explosion shock wave pressure test were performed, and the model calculation accuracy was verified by using the obtained shock wave pressure data. The Validation results show that the model had 84% calculation accuracy and could well reflect the explosion shock wave pressure distribution law. Furthermore, the results provided a new calculation method and scientific data support for the accurate evaluation of the damage power of an ammunition explosion. Additionally, the results are significant for applications in engineering testing and the military.

Background: The risk of coronary artery disease increases with increasing of blood pressure both in hypertensive and normotensive persons; on the other hand nutritional factors have a significant effect on blood pressure. Objective: To determine the effect of daily sodium, potassium, calsium Intake and BMI on blood pressure. Methods: This cross-sectional study was implemented on 195 nonpregnant normotensive women aged 15-46 years in Marand in 1999. Food Intake was assessed by 24-hour recall method during two consequent days and daily nutrient Intake was calculated using food processor software. Weight, height and blood pressure were measured and then BMI was calculated by weight / height2 formula. Findings: Results showed a direct significant relation between daily sodium Intake with systolic (SBP) and diastolic blood pressure (DBP) (p= 0.05 , p= 0.01) and also intaking daily sodium per 1000 kcal the relation was stronger (p=0.008 , p=0.006) .SBP and DBP had  an inverse  signinficant  relation  with daily potassium  Intake (p=0.05 , 0.04) . Na/K ratio relationship with  SBP and DBP  was stronger than sodium and potassium alone ( P =0.005 , p<0.0001), there were no significant relation between daily calcium Intake and blood pressure. BMI had signicant effect on DBP but not on SBP. Conclusion: Based on these results reducing sodium Intake, increasing potassium Intake and controlling weight are recommended so as to control blood pressure.