This study evaluates improvement of the acetabular index (AI) in patients with developmental dysplasia of the hip at 4 years after closed reduction, and determines the association between the final AI and a set of factors. Sixty-two patients (74 hips) treated with closed reduction were categorized into three groups according to age: group A (0-12 months, 18 hips), group B (13-18 months, 24 hips), and group C (>18 months, 32 hips). There was no difference in AI among the three groups before reduction (P=0.293). In groups A and C, the AI decreased significantly over time until 3 years after reduction and no differences were observed between the time points of 3 and 4 years. At 4 years after reduction, the AI of group C was significantly higher than that of groups A (P<0.001) and B (P=0.012). The overall AI improvement rate was 28.63%. The AI improvement rate of group A was significantly higher than that of group C (P=0.005). Pearson correlation analysis indicated no correlation between center-head distance discrepancy and the final AI (P=0.811). Linear regression suggested that age and initial AI correlated significantly with the final AI (R=0.617, F=15.031, P<0.001). Other factors, such as sex, center-edge angle of Wiberg, bilaterally involved, and avascular necrosis of the femoral head, showed no correlations with the final AI (P>0.05). According to the coefficients, initial AI (β1=0.432, P<0.001) had greater effect than age (β2=0.197, P=0.023) on the final AI. In conclusion, the AI decreases in all patients after reduction and stabilizes at 3 years after reduction. The AI improvement rate is correlated negatively with age. Age and initial AI are early predictors of the progress of AI after closed reduction in developmental dysplasia of the hip patients.

With the rapid development of aviation technology, the performance of aero-engine continues to increase in China. However, Chinese Aero-engine lubricating oil real-time measurement technology is not mature, active airplane almost have no Aero-engine lubricating oil real-time measurement system, It requires further in-depth study.By research on Aero-engine lubricating oil measurement technology. First, it outlined the method and principles of measurement, and based on UG Open the analysis of Aero-engine lubricating oil system was developed. Through which an analysis of the model of Aero-engine lubricating oil, the spatial databases about sensor depth of immersion oil, aircraft attitude and fuel volume were built.,which can provide the data for the subsequent lubricating real-time oil measuring analysis .

Chaos algorithm is essential in weak signal detection because of its sensibility to weak signals and immunity to noise. This paper applies subspace algorithm which originates from array signal processing to weak signal detection field because of its lower signal to noise ratio. Firstly, the article introduces the principles of two algorithms, then analyses simulation experiments results of real signal data. After that, a conclusion for two algorithms comparison by estimation of computation cost, complexity of implementation and hardware resources occupied is drawn. At the end, the writer designs a duffing chaos module which is the core part of chaotic detection with verilog-hdl.

The stress and deformation of cut-off wall will be changed as the water level cyclical varying during reservoir's operation. Therefore, the prediction is important to the safety and stability of reservoir. In this paper, the seepage characteristics of the highest and the lowest water level condition have been predicted, and the variation of horizontal displacement is discussed under the vehicle load of road and cyclical fluid load. Meanwhile, the displacement distribution and stress state in junction area of the upper wall and the lower wall are obtained. The results show that the Cut-off wall is less affected by the vehicle load of road, and its stress and deformation will gradually stabilize after the second water store-discharge cycle. The upper reinforced concrete wall will tilt towards outside of reservoir, but the deformation is very small at lower plastic concrete wall. The guide wall has a good effect on preventing the upper wall's inclining and improving the lower wall's stress environment. Besides, the maximum principle stress of cut-off wall is too small to course plastic failure.