Braking Torque Analysis and Control Method of a New Motor with Eddy-Current Braking and Heating System for Electric Vehicle

Zhao Xiaojuan,Zhang Yulong,Ye Lezhi 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.5

To solve the problem of the serious mileage reduction of electric vehicles in winter, this paper introduces a new type of motor with eddy current braking and heating system (EBHS). EBHS can convert the vehicle’s kinetic energy into the thermal energy which can be used for heating the cabin and the battery at the right temperature. This paper proposes the structural layout and operating modes with the novel motor. The air gap magnetic density of the ECR is calculated by the magnetic circuit method. The braking torque is solved by the transient electromagnetic finite element method. The eddy current loss power at different speeds is used for analyzing heat performance. Based on MATLAB / Simulink environment, the fuzzy control method is used to simulate the EBHS’s braking energy efficiency. Compared with PTC heating, the power consumption of the new motor is reduced by 25 % and the cabin can reach 20 °C in 160 seconds. Finally, it is verified by bench test that the retarder stator stayed within 110 °C when it is continuously operated for 12 minutes. The braking torque of the finite element analysis result meet the test value, and the error rate is not higher than 11.7 %.

Synthesis of 3'-C-Hydroxymethyl-substituted Pyrimidine and Purine Nucleosides as Potential Anti-Hepatitis C Virus (HCV) Agents

Xiaojuan Pei,최원준,김유민,Long Xuan Zhao,정낙신 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.7

On the basis of potent anti-hepatitis C virus (HCV) activity of 2'-C-hydroxymethyladenosine, 3'- C-hydroxymethyl-substituted pyrimidine and purine nucleosides as potential anti-HCV agents were designed and synthesized from D-xylose via stereoselective Grignard reaction and conversion of the vinyl into hydroxymethyl group as key steps.

Effect of Ligustilide Supplement on Physical Fitness of Athletes

Xiaojuan Gao,Shuai Yang,Meng Liu,Yawen Jiang,Li Wenyan,Rui Ma,Zijian Zhao,Xuelin Zhang 아시아건강운동학회 2020 Journal of Asian Society for Health & Exercise Vol.2 No.2

PURPOSE: In this study, high content ligustilide plant extract was supplemented to monitor the changes of physical fitness and physiological function of athletes, and to explore the effect of ligustilide plant extract on physical function and physical fitness of athletes. METHODS: Thirty five high-level basketball players from Zhengzhou University were selected and divided into two groups randomly: nutritional supplement group (S, n = 18) and control group (C, n=17). This study was approved by the Ethics Committee of Zhengzhou University. Informed consent was obtained from each subject. The intervention period was 8 weeks, six days per week. The training method adopted the small cycle plate training scheme. We measured changes of the scores of rating of perceived exertion (RPE), physical fitness test (15m running, 30m running, 400m running) and routine blood test (mainly including red blood cell count, hemoglobin concentration and average erythrocyte hemoglobin concentration, etc.) before and after training. RESULTS: In group S, the percentage of RPE (grade 6-11) and RPE (grade 12-18) before experiment was 37.5% and 62.5%. After 8 weeks of experiment, 62.5% of RPE (grade 6-11) and 37.5% of RPE (grade 12-18). In group C, 14% of RPE (grade 6-11), 86% of slight RPE (grade 12-18), and 100% of RPE (grade 12-18) after 8 weeks of experiment. It was found that after 8 weeks of training, the number of red blood cells, the concentration of hemoglobin and the average concentration of red blood cell hemoglobin in group S were significantly higher than those before the experiment (p <0.05). According to the comparison of the physical fitness test results of the athletes in group S, it was found that the performance of 400m after 4 weeks and 8 weeks was significantly higher compared with pre-experiment (p<0.05). The changes of 30m and 15m were not significant different (p>0.05). The 400-meter test performance of athletes in group C was significantly higher than that before the experiment only after 8 weeks of training (p<0.05). CONCLUSIONS: Ligustilide supplementation can increase the number of red blood cell and hemoglobin concentration of athletes and has a positive impact on the physical fitness of athletes and the recovery of fatigue.

A modified RBSM for simulating the failure process of RC structures

Chao Zhao,Xingu Zhong,Bo Liu,Xiaojuan Shu,Mingyan Shen 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.21 No.2

In this paper, a modified rigid body spring model (RBSM) is proposed and used to analyze the damage and failure process of reinforced concrete (RC) structures. In the proposed model, the concrete is represented by an assembly of rigid blocks connected with a uniform distribution of normal and tangential springs to simulate the macroscopic mechanical behavior of concrete. Steel bars are evenly dispersed into rigid blocks as a kind of homogeneous axial material, and an additional uniform distribution of axial and dowel springs is defined to consider the axial stiffness and dowel action of steel bars. Perfect bond between the concrete and steel bars is assumed, and tension stiffening effect of steel bars is modeled by adjusting the constitutive relationship for the tensile reinforcement. Adjacent blocks are allowed to separate at the contact interface, which makes it convenient and easy to simulate the cracking process of concrete. The failure of the springs is determined by the Mohr-Coulomb type criterion with the tension and compression caps. The effectiveness of the proposed method is confirmed by elastic analyses of a cantilever beam under different loading conditions and failure analyses of a RC beam under two-point loading.

Benefits of procyanidins on gut microbiota in Bama minipigs and implications in replacing antibiotics

Tingting Zhao,Xiaojuan Shen,Chang Dai,Li Cui 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.6

Several studies have reported the effect of absorption of procyanidins and their contribution to the small intestine. However, differences between dietary interventions of procyanidins and interventions via antibiotic feeding in pigs are rarely reported. Following 16S rRNA gene Illumina MiSeq sequencing, we observed that both procyanidin administration for 2 months (procyanidin-1 group) and continuous antibiotic feeding for 1 month followed by procyanidin for 1 month (procyanidin-2 group) increased the number of operational taxonomic units, as well as the Chao 1 and ACE indices, compared to those in pigs undergoing antibiotic administration for 2 months (antibiotic group). The genera Fibrobacter and Spirochaete were more abundant in the antibiotic group than in the procyanidin-1 and procyanidin-2 groups. Principal component analysis revealed clear separations among the three groups. Additionally, using the online Molecular Ecological Network Analyses pipeline, three co-occurrence networks were constructed; Lactobacillus was in a co-occurrence relationship with Trichococcus and Desulfovibrio and a co-exclusion relationship with Bacillus and Spharerochaeta. Furthermore, metabolic function analysis by phylogenetic investigation of communities by reconstruction of unobserved states demonstrated modulation of pathways involved in the metabolism of carbohydrates, amino acids, energy, and nucleotides. These data suggest that procyanidin influences the gut microbiota and the intestinal metabolic function to produce beneficial effects on metabolic homeostasis.

Synthesis of 3'-C-Hydroxymethyl-substituted Pyrimidine and Purine Nucleosides as Potential Anti-Hepatitis C Virus (HCV) Agents

Pei, Xiaojuan,Choi, Won-Jun,Kim, Yu-Min,Zhao, Long Xuan,Jeong, Lak-Shin 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.7

On the basis of potent anti-hepatitis C virus (HCV) activity of 2'-C-hydroxymethyladenosine, 3'-C-hydroxymethyl-substituted pyrimidine and purine nucleosides as potential anti-HCV agents were designed and synthesized from D-xylose via stereoselective Grignard reaction and conversion of the vinyl into hydroxymethyl group as key steps.

A 3-D RBSM for simulating the failure process of RC structures

Zhong, Xingu,Zhao, Chao,Liu, Bo,Shu, Xiaojuan,Shen, Mingyan Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.3

Rigid body spring method (RBSM) is an effective tool to simulate the cracking process of structures, and has been successfully applied to investigate the behavior of reinforced concrete (RC) members. However, the theoretical researches and engineering applications of this method mainly focus on two-dimensional problems as yet, which greatly limits its applications in actual engineering projects. In this study, a three-dimensional (3-D) RBSM for RC structures is proposed. In the proposed model, concrete, reinforcing steels, and their interfaces are represented as discrete entities. Concrete is partitioned into a collection of rigid blocks and a uniform distribution of normal and tangential springs is defined along their boundaries to reflect its material properties. Reinforcement is modeled as a series of bar elements which can be freely positioned in the structural domain and irrespective of the mesh geometry of concrete. The bond-slip characteristics between reinforcing steel and concrete are also considered by introducing special linkage elements. The applicability and effectiveness of the proposed method is firstly confirmed by an elastic T-shape beam, and then it is applied to analyze the failure processes of a Z-type component under direct shear loading and a RC beam under two-point loading.

Effects of Aging Time on the Antioxidant Activity of Pomelo Wine

Muying Du,Yuming You,Xiaojuan Zhao,Fusheng Zhang,Meiling Tian,Jianquan Kan 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.4

Variations in amino acid and volatile component contents, and in total flavonoid, polyphenol contents and their vitro antioxidant activities at different aging times of pomelo wine were investigated; scavenging rates against DPPH, ABTS, and ferric reducing antioxidant powers were also explored. Most amino acids reached maximum values in the third aging year; and volatile components of pomelo wine also indicated good wine quality in the third year. Total flavonoid and polyphenol contents in pomelo wine were increased and antioxidant activities enhanced during the first 3 years. Samples aged for 3 years had the highest total flavonoid and total polyphenol contents, and the strongest antioxidant activities (38.23±2.16% for DPPH· scavenging effect, 91.84±4.14% for ABTS· scavenging effect, and 0.90±0.07 mmol/L for FRAP value). These parameters gradually decreased after the 3 year period. A significant (p<0.05) correlation between antioxidant activity, and total flavonoid and polyphenol contents was identified.

A 3-D RBSM for simulating the failure process of RC structures

Xingu Zhong,Chao Zhao,Bo Liu,Xiaojuan Shu,Mingyan Shen 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.3

Rigid body spring method (RBSM) is an effective tool to simulate the cracking process of structures, and has been successfully applied to investigate the behavior of reinforced concrete (RC) members. However, the theoretical researches and engineering applications of this method mainly focus on two-dimensional problems as yet, which greatly limits its applications in actual engineering projects. In this study, a three-dimensional (3-D) RBSM for RC structures is proposed. In the proposed model, concrete, reinforcing steels, and their interfaces are represented as discrete entities. Concrete is partitioned into a collection of rigid blocks and a uniform distribution of normal and tangential springs is defined along their boundaries to reflect its material properties. Reinforcement is modeled as a series of bar elements which can be freely positioned in the structural domain and irrespective of the mesh geometry of concrete. The bond-slip characteristics between reinforcing steel and concrete are also considered by introducing special linkage elements. The applicability and effectiveness of the proposed method is firstly confirmed by an elastic T-shape beam, and then it is applied to analyze the failure processes of a Z-type component under direct shear loading and a RC beam under two-point loading.

2-D meso-scale complex fracture modeling of concrete with embedded cohesive elements

Mingyan Shen,Zheng Shi,Chao Zhao,Xingu Zhong,Bo Liu,Xiaojuan Shu 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.24 No.3

This paper has presented an effective and accurate meso-scale finite element model for simulating the fracture process of concrete under compression-shear loading. In the proposed model, concrete is parted into four important phases: aggregates, cement matrix, interfacial transition zone (ITZ), and the initial defects. Aggregate particles were modelled as randomly distributed polygons with a varying size according to the sieve curve developed by Fuller and Thompson. With regard to initial defects, only voids are considered. Cohesive elements with zero thickness are inserted into the initial mesh of cement matrix and along the interface between aggregate and cement matrix to simulate the cracking process of concrete. The constitutive model provided by ABAQUS is modified based on Wang’s experiment and used to describe the failure behaviour of cohesive elements. User defined programs for aggregate delivery, cohesive element insertion and modified facture constitutive model are developed based on Python language, and embedded into the commercial FEM package ABAQUS. The effectiveness and accuracy of the proposed model are firstly identified by comparing the numerical results with the experimental ones, and then it is used to investigate the effect of meso-structure on the macro behavior of concrete. The shear strength of concrete under different pressures is also involved in this study, which could provide a reference for the macroscopic simulation of concrete component under shear force.