Research on the Improvement of Calculation Method for the Interference Assembly of Locomotive Traction Gear

The interference assembly is the main method for the connection between the traction gear and the shaft. The selection of the interference plays a critical role in the design of the traction gear. The traditional method of the calculation of the interference of the traction gear oversimply the mathematical model. The error goes out of the acceptable range so that the old method is not suitable for the design of the web structure. In this paper we propose an improved algorithm for solving the interference of the traction gear by combining the classical elastic mechanics theory and the finite element segmentation technique. The results from our improved algorithm is compared with that from the traditional method and the finite element simulation data is compared with the experimental results. Both comparisons verified the rationality and the feasibility of our algorithm. Our research provides the theoretical reference significance and practical guiding value for the selection of the range of interference

Design of Individualized Wheelchairs Using AHP and Kano Model

To study how to design different grades of individualized wheelchairs according to users' needs, a personalized wheelchair design method based on AHP and Kano model is proposed. The AHP model determines the relative importance of characteristics of customers' demands. The subfunctions of manual wheelchairs and their attributes are given. The weight coefficients are calculated. 20 experts (10 are the members of the research team, 5 are doctors, and 5 are wheelchair designers) are involved in the above two parts of the work. Kano model represents the types of user requirements. 30 participants' (wheelchair users) needs are divided into 5 categories: M, O, E, I, and R. According to the types of user needs and the weight of each subfunction, three manual wheelchair models are built. Traditional design method usually cannot satisfy the requirements of users and product structure, so this paper makes a contribution to solve this problem. The method can be used to design individualized wheelchairs which may improve the product quality and customers' satisfaction. Meanwhile it also can reduce the design time, thereby reducing the design cost

Modeling and Simulation for Nutation Drive with Rolling Teeth

According to the nutation movement of a rotating coin on a table, a novel nutation drive with rolling teeth is presented on the basis of oscillating teeth gear transmission. Firstly, the structure of mechanism is provided and transmission theory is declared. The formulae for calculating the transmission ratio of the mechanism is developed. Secondly, the modeling of this nutation drive is built. Finally, the results of theoretical calculations are verified by dynamic motion simulation of the prototype mechanism. In addition, Numerical control(NC) simulation of machining the stator and the rotor gears is developed.No Full Tex

Structural Failure Trends of the Assembly Welding Fixture for the Front Sidewall on the basis of Finite Element Analysis

The operating conditions of the assembly welding fixture for the front sidewall have been analyzed in this paper, and all the typical conditions have been applied with the nonlinear finite element analysis of the contact, aiming to ensure the safe utilization of the assembly welding fixture for the front sidewall of tooling equipment for the production of rail vehicles. The potentially risky component locations are predicted and the weak spots are discovered on the basis of the analysis results of the static strength. The anticipation of the component failure trends shows a guiding role in the failure prediction in actual production and facilitates accident prevention

Structural Failure Trends of the Assembly Welding Fixture for the Front Sidewall on the basis of Finite Element Analysis

The operating conditions of the assembly welding fixture for the front sidewall have been analyzed in this paper, and all the typical conditions have been applied with the nonlinear finite element analysis of the contact, aiming to ensure the safe utilization of the assembly welding fixture for the front sidewall of tooling equipment for the production of rail vehicles. The potentially risky component locations are predicted and the weak spots are discovered on the basis of the analysis results of the static strength. The anticipation of the component failure trends shows a guiding role in the failure prediction in actual production and facilitates accident prevention

Molybdenum dioxide as an alternative catalyst for direct utilization of methane in tubular solid oxide fuel cells

Direct utilization of methane in conventional tubular solid oxide fuel cells (SOFCs) with a Ni-YSZ anode support was proposed using MoO2 as a partial oxidation catalyst for methane reforming at the cell inlet. A promising stability was achieved for a continuous operation in a mixture of methane and air (1, 1.5) for > 150 h under a load voltage of 0.7 V at 750 degrees C. The addition of the MoO2 catalyst at the anode inlet made tubular SOFCs with the conventional Ni-YSZ anode an efficient and practically promising candidate for direct hydrocarbon utilization

Comparative Transcriptomics and Gene Knockout Reveal Virulence Factors of Arthrinium phaeospermum in Bambusa pervariabilis × Dendrocalamopsis grandis

Arthrinium phaeospermum can cause branch wilting of Bambusa pervariabilis × Dendrocalamopsis grandis, causing great economic losses and ecological damage. A. phaeospermum was sequenced in sterile deionized water (CK), rice tissue (T1) and B. pervariabilis × D. grandis (T2) fluid by RNA-Seq, and the function of Ctf1β 1 and Ctf1β 2 was verified by gene knockout. There were 424, 471 and 396 differentially expressed genes between the T2 and CK, T2 and T1, and CK and T1 groups, respectively. Thirty DEGs had verified the change in expression by fluorescent quantitative PCR. Twenty-nine DEGs were the same as the expression level in RNA-Seq. In addition, ΔApCtf1β 1 and ΔApCtf1β 2 showed weaker virulence by gene knockout, and the complementary strains Ctf1β 1 and Ctf1β 2 showed the same virulence as the wild-type strains. Relative growth inhibition of ΔApCtf1β 1 and ΔApCtf1β was significantly decreased by 21.4% and 19.2%, respectively, by adding H2O2 compared to the estimates from the wild-type strain and decreased by 25% and 19.4%, respectively, by adding Congo red. The disease index of B. pervariabilis × D. grandis infected by two mutants was significantly lower than that of wild type. This suggested that Ctf1β genes are required for the stress response and virulence of A. phaeospermum

Comparative Transcriptomics and Gene Knockout Reveal Virulence Factors of <i>Arthrinium phaeospermum</i> in <i>Bambusa pervariabilis × Dendrocalamopsis grandis</i>

Arthrinium phaeospermum can cause branch wilting of Bambusa pervariabilis × Dendrocalamopsis grandis, causing great economic losses and ecological damage. A. phaeospermum was sequenced in sterile deionized water (CK), rice tissue (T1) and B. pervariabilis × D. grandis (T2) fluid by RNA-Seq, and the function of Ctf1β 1 and Ctf1β 2 was verified by gene knockout. There were 424, 471 and 396 differentially expressed genes between the T2 and CK, T2 and T1, and CK and T1 groups, respectively. Thirty DEGs had verified the change in expression by fluorescent quantitative PCR. Twenty-nine DEGs were the same as the expression level in RNA-Seq. In addition, ΔApCtf1β 1 and ΔApCtf1β 2 showed weaker virulence by gene knockout, and the complementary strains Ctf1β 1 and Ctf1β 2 showed the same virulence as the wild-type strains. Relative growth inhibition of ΔApCtf1β 1 and ΔApCtf1β was significantly decreased by 21.4% and 19.2%, respectively, by adding H2O2 compared to the estimates from the wild-type strain and decreased by 25% and 19.4%, respectively, by adding Congo red. The disease index of B. pervariabilis × D. grandis infected by two mutants was significantly lower than that of wild type. This suggested that Ctf1β genes are required for the stress response and virulence of A. phaeospermum