The effects of high O2 atmosphere packaging on postharvest respiration and quality attributes of purple passion fruit were investigated. Freshly harvested fruit were placed and sealed into polyolefin (PO) bags with 50%, 70%, 90% O2 (balance N2) or air (as control) atmosphere up to 20 days at 15°C. Samples were randomly selected initially and at 5‐days interval during storage. The fruit packaged in high O2 atmosphere had lower respiration rate and peel shrinkage than that of control. High O2 atmosphere packaging had good effect on maintaining high levels of vitamin C, soluble solids content, total phenols, and total flavonoids of passion fruit, and the higher one had better effect. These results indicate that high O2 atmosphere packaging could inhibit the postharvest respiration and retain good physical properties and nutritional properties of passion fruit. Practical application Passion fruit is vulnerable to deterioration and has a short shelf life after harvest. In our present study, high O2 (90%) atmosphere packaging effectively inhibited respiration and peel shrinkage, maintained firmness, vitamin C and soluble solids content, and increased total phenols content and total flavonoids content of passion fruit. Thus, high O2 atmosphere packaging will be a prospective way to extend shelf life of passion fruit.

As cars become more and more quiet the sound quality of rotary components such as car compressor becomes more important in the customer’s subjective perception of passenger car quality. This needs a new evaluation method which is not only the traditional method like sound pressure level but also Psychoacoustic Metrics to focus the specification of component sounds. This paper on one hand analyzed one car’s abnormal noise reason through the tests, found the main problem frequency band of the compressor, and on the other hand studied the compressor’s psychoacoustic metrics. In this paper the countermeasure of solving this problem was also given, and then noise level and psychoacoustic parameters are compared. Both objective evaluation and subjective evaluation showed that the compressor with the solution not only reduced the sound pressure level, but also improved the car sound quality greatly.

As cars become quieter the sound quality of components becomes more critical in the customer perception of car quality. Considering that middle frequency noise plays an important roll for internal noise, the noise signals in the range from200Hz to 500Hz are specially emphasized. Then the acoustic evaluation parameters, such as Sound Pressure Level, Acceleration have been evaluated. Judged from experiences and measuring results, an abnormal noise comes from engine mounts, through the use of dynamic vibration absorber on engine mounts, Vibration on engine mounts and Sound Pressure Level in interior vehicle were greatly improved. At the same time, subjective evaluation also indicated that there was no complaint any more in passenger compartment. Dynamic vibration absorber can properly solve the abnormal noise.

As cars become quieter the sound quality of components becomes more critical in the customer perception of car quality. This requires a need of new evaluation method for the specification of component sounds. Considering that high frequency noise plays an important roll for internal noise, the noise signals in the range from 7000Hz to 8000Hz are specially emphasized. Then the acoustic evaluation parameters, such as Sound Pressure Level, Sharpness and Steadiness have been evaluated. Judged from experiences and measuring results, an abnormal noise comes from Generator, through the exchange of Generator, Sound Pressure Level and sharpness were greatly improved. At the same time, subjective evaluation also indicated that there was no complaint any more in passenger compartment. Low Sound Pressure Level, sharpness can lead to perceived high product quality.