The structure and principle of the two-stage pressure hydro-pneumatic spring were introduced. the physical and dynamic vehicle models with it were established under AMESim environment. Static characteristic curves of the two-stage pressure hydro-pneumatic spring were drawn. A single chamber hydro-pneumatic spring was used to compare the suspension dynamic travel and body vertical acceleration of the vehicles equipped with two-stage pressure hydro-pneumatic spring. The results show that two-stage pressure hydro-pneumatic spring can effectively enhance the vehicle riding comfort by decreasing body vibration.

The patient was a 26-year-old man who complained of headache and vomiting. On examination, there was nothing abnormal, but the edge of the right optic papilla was not clear. His temperature was 38.5 degrees C, pulse 96/min, blood pressure 120/80 mmHg. A space-occupying lesion in his fronto-dextra cupular part was found by CT scanning. He had a 12-year history of chronic purulent otitis. The diagnosis was a brain abscess in the fronto-dextra cupular part. The brain abscess was extracted and Pasteurella multocida was isolated from the dark brown pus draining from the abscess. The patient recovered through proper antibiotic therapy based on a sensitivity test. Reports of infections caused by this organism in foreign countries very widely from local infections due to bites and scratches by cats, dogs etc. to general infections such as infections of the respiratory tract, sepsis and meningitis. However, Pasteurella multocida brain abscesses are rare. Pasteurella multocida is a Gram-negative short rod which is best known as part of the mouth flora and as a pathogen causing septicemia in many domestic animals, such as cats, dogs etc.. Infection in man results mainly from animal bites or scratches. It has been reported that Pasteurella multodida can cause human septicemia, meningitis, respiratory tract infection, conjunctivitis and other infections. We isolated a strain of Pasteurella multocida from the pus of a brain abscess following chronic purulent otitis on August 6, 1990.

Air spring gas is generally regarded as an ideal gas in analysis , but this is not consistent with the actual work . Considerring influence of non-ideal gas to air spring stiffness ,and based on van der Waals equation which is closed to the real gas equation, stiffness characteristics model of air spring and air spring with auxiliary chamber are re-derived and established. Influence of non ideal gas correction factor H to air spring stiffness is analysed within the range of pressure 0.2MPa to 5 MPa and working temperature -50 °C to 50°C,and results show that , there are big errors in air spring stiffness model in the conditon of low temperature and high pressure based on ideal gas equation, and range of application of the stiffness model is expanded when H is introduced and amended.

An electronically controlled air suspension system has been introduced to improve the ride performance of a vehicle. A fuzzy controller is designed on the basis of fuzzy logic control strategy which is applied to control the air suspension system. The vibration reduction of a coach with the suspension system is achieved by controlling the stiffness of the air spring and the damping of a switchable damper. A nonlinear dynamic model of a half-vehicle is used to simulate traditional air suspension and the one with fuzzy controller for ride performance respectively on road input. The results indicate that implementing a control strategy can improve the ride performance of the coach on the condition of normal road.

The truck with Electrically Controlled Air Suspension(ECAS) could reduce the loss of goods by setting running height when transporting, and to enhance the loading &unloading efficiency, a height modulating model was built by combining the theories of thermodynamics of variable-mass charging-discharging system and the vehicle kinetics. To solve such problems as “over-charging”, “over-discharging” and surging, a height control strategy of variable integral PID/PWM was proposed and its controller was developed base on the Freescale single chip. Finally the semi-physical rig was built for simulating the truck with the height controller, and the testing results show that the designed control system satisfies the requirement of height modulation.