Objective A novel high-speed three-way solenoid valve is developed, which is used for the common-rail injection system equipped on DME powered engine. In order to improve the dynamic response performance of the three-way solenoid. Methods Experimental studies have been conducted to investigate the effects of spool stroke, drive voltage, negative demagnetizing pulse and two drive schemes on the dynamic response performance of the three-way solenoid valve. Results The results show that the dynamic response performance of the three-way solenoid valve can be remarkably improved by shortening the spool stroke and increasing the drive voltage. Simultaneously, the difference between the response time of closing valve and that of opening valve decreases. At each different drive voltage, there exists an optimal negative demagnetizing pulse corresponding to the same positive exciting pulse. At this optimal pulse,the dynamic response performance of the three-way solenoid valve is the best. In addition, the high drive voltage can lead to the smaller optimal negative demagnetizing pulse. It is also indicated from the experiments that the dynamic response performance of the three-way solenoid valve is better when the NO. 1 drive scheme is adopted. The lower drive voltage results in the larger difference between the dynamic response performances for the two drive schemes.Conclusion The dynamic response performance of a novel three-way solenoid valve is good.

Joint contracture is currently one of the very common diseases in rehabilitation medicine department.Once it occurs,it likely leads to such functional disturbances in the patients as restricted joint activities,decreased muscle strength around a joint and abnormal gait,seriously affecting the quality of life of the patients.Studies on its pathogenesis can help doctors better understand and treat the disease.In this paper,pathogenesis of the disease and progress in its therapy are summarized.

Objective To establish a model of knee joint extension contracture in New Zealand white rab-bits, and to lay the experimental foundation for further studies on the pathogenesis and treatment of joint contractures. Methods Thirty male New Zealand white rabbits with mature bones were randomly divided into 6 groups. The left knee joints of the immobilization groups ( 5 groups of 5 rats each) were fixed in extension for 1, 2, 4, 6 or 8 weeks. There was also a control group. At the end of each period the plaster was demolished and the level of transforming growth factor-β1 ( TGF-β1) in joint cavities, the degree of total contracture, myogenic contracture, arthrogenic con-tracture, and the thickness of the posterior joint capsules were measured. The significance of the differences between the immobilized groups and the control group was compared using one-way analysis. Results The level of TGF-β1 in the joint fluid differed significantly among the 6 groups. The differences in the degree of total contracture among the control group, one-week, two-week and four-week groups were also significant. The average degree of the myogenic contracture in the one-week group was significantly different from the other 5 groups' averages. The average myogenic contracture was also of significantly different between the two-week group and the control group. The degree of arthro-genic contracture was significantly different among the groups except for between the 6-week and 8-week groups. The average joint capsule thickness was significantly different among all of the groups except for between the control group and the one-week group. Conclusion This technique for modeling knee extending contracture using New Zealand white rabbits is simple and practical. It provides a better animal model for studying the mechanism of knee joint con-tracture and related treatment strategies and can be used for further exploration of the occurrence and recovery of knee contractures.