Search

In order to solve the adverse effect on wheel-hubdriven electric vehicle ride comfort caused by the introduction of hub motor, a three-step screening method is proposed to match and optimize the hard point parameters of vehicle suspension. First, a multibody dynamic model of the prototype vehicle suspension was established based on a multibody dynamic method, and the analytical formulas of the electromagnetic force of the motor were given. Based on the specific conditions of the vehicle and the motor, a dynamics analysis of the suspension was carried out to investigate the effect of the fluctuation of the electromagnetic force of the hub motor on the wheel alignment parameters. Second, the calculation model of the suspension dynamics response was established according to the experiment designed by the Latin hypercube sampling method, and a sensitivity analysis of the suspension hard point coordinate was carried out to obtain the sensitive hard point parameters. Finally, the linear weighted synthetic optimization model of the front wheel alignment parameters of the wheel-hubdriven electric vehicle was elaborated using a multi-objective optimization method, and the multi-objective function was converted into a single objective evaluation function to carry out better suspension hard point parameter optimization. The results show that by optimizing the suspension hard point parameter, the wheel alignment parameters can be controlled within a reasonable range. This optimization ensures that the variation rate of the front wheel alignment parameters of the wheel-hubdriven electric vehicle meets the vehicle design requirements, thus eliminating the adverse impact on vehicle ride comfort caused by the introduction of the hub motor. This paper also illustrates that the three-step screening method is an efficient method of parameter matching, which can satisfactorily solve the problem of engineering applications. The three-step screening method can teach assistant engineer how to use this method to conveniently carry out the design of vehicle suspension, simplify the cumbersome design process, save time, and improve work efficiency and design quality.

ObjectiveTo investigate the pathology, clinical features, population features, and etiology of non-viral hepatitis-related abnormal liver function in the elderly. MethodsA retrospective analysis was performed for 50 elderly patients, with abnormal liver function as disease onset for the first time, who were hospitalized and treated in Beijing YouAn Hospital, Capital Medical University, from January 2017 to September 2019. Abnormal liver function was defined as elevated alanine aminotransferase (≥2×upper limit of normal), with or without the increases in the serum levels of aspartate aminotransferase, total bilirubin, alkaline phosphatase, and gamma-glutamyl transpeptidase, and there was no limit for the duration of abnormal liver function. According to the method for obtaining pathological specimens, the patients were divided into percutaneous liver biopsy group and transjugular liver biopsy group. The etiology of abnormal liver function was analyzed, and clinical features and laboratory markers were summarized. The t-test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test was used for comparison of categorical data between two groups. ResultsA total of 50 patients were enrolled, with a mean age of 64.7±3.7 years, and there were 19 male patients and 31 female patients. Of all patients, 21 underwent transjugular liver biopsy and 29 underwent percutaneous liver biopsy. Pathological examination showed that 20 patients (40.0%) were diagnosed with drug-induced liver injury, among whom 3 had autoimmune phenomena, 1 had liver failure, and 4 had hepatic veno-occlusive disease/hepatic sinusoidal obstruction syndrome; 5 patients (10.0%) were diagnosed with autoimmune liver disease, among whom 3 had primary biliary cholangitis and 2 had autoimmune hepatitis (1 patient already had liver cirrhosis); 4 patients (8.0%) were diagnosed with nonalcoholic fatty liver disease. The etiology was not determined for 16 patients (32.0%), among whom 8 had liver cirrhosis, 6 had hepatitis, and 2 had bile duct disease. In addition, there were 2 patients with non-cirrhotic portal hypertension (4.0%), 1 patient with amyloidosis (2.0%), and 2 patients with liver failure (4.0%). ConclusionDrug-induced liver injury has the highest incidence rate among non-viral hepatitis-related abnormal liver function in the elderly, which is often associated with the use of drugs for chronic diseases and Chinese patent drugs. Transjugular liver biopsy may help to determine the etiology of severe liver diseases.

Objective We aimed to assess significant liver histological injury(SLHI) of chronic hepatitis B (CHB) patients with normal ALT in order to select clinical threshold of ALT. Methods We retrospectively examined 347 patients who underwent liver biopsy in Beijing You an hospital, Capital Medical University from January 2018 to January 2021. Univariate analysis of the clinical parameters versus inflammation and fibrosis was carried out. Results Of these 347 patients met the inclusion criteria, 174(50.1%) patients had SLHI totally.The AUROC of the ALT associated with the diagnosis of SLHI was 0.572 for female and 0.6 for male with a cut-off value of 20U/L and 25U/L, respectively (p = 0.04, p = 0.013).Among HBeAg-positive patients,the proportion of SLHI in the high-normal ALT group (ALT > 20 U/L for female,>25 U/L for male) with low HBV DNA loads(

On April 10, 2021, the China State Administration for Market Regulation made an administrative penalty decision as per stipulated legislation, ordering Alibaba Group to stop illegal behavior and imposed a fine of 4% of its 2019 sales within China of 457.512 billion yuan, totaling 18.228 billion yuan.This penalty is the highest penalty the China government had ever imposed in the antitrust field. The Alibaba Group did not pose any objections and stated that they would accept the penalties and follow the following instructions provided by the SAMR.

To study the ride comfort of wheel-hub-driven electric vehicles, a simulation and verification method based on a combination of ADAMS and MATLAB modeling is proposed. First, a multibody dynamic simulation model of an in-wheel motor-driven electric vehicle is established using ADAMS/Car. Then, the pavement excitation and electromagnetic force analytical equations are provided based on the specific operating conditions of the vehicle and the in-wheel motor to analyze the impact of the electromagnetic force fluctuation from an unsprung mass increase and motor air gap unevenness on vehicle ride comfort after the introduction of an in-wheel motor. Next, the vibration model and the motion differential equation of the body–wheel dual-mass system of an in-wheel motor-driven electric vehicle are established. The influence of the in-wheel motor on the vibration response index of the dual-mass system is analyzed by using MATLAB/Simulink software. The variation in the vehicle vibration performance index with/without the motor electromagnetic force excitation factor is analyzed and compared with the ADAMS multibody dynamics analysis results. The results show that the method based on a combination of ADAMS and MATLAB modeling can forecast the ride comfort of an in-wheel motor-driven electric vehicle, reducing the cost of physical prototype experiments.

The body-in-white simulation model of a certain commercial vehicle was established to make a numerical analysis of the vehicle body static stiffness in this research. Meanwhile, the effectiveness of the simulation model was verified using the physical test of body-in-white static stiffness. Research results showed that the error of body-in-white static stiffness test and simulation analysis was within the range of ±10 %, which could reduce the test cost and guarantee the test precision. The research findings do provide a better application value and references for vehicle engineering developers.