Chang Lv

Design of Steering Driven Axle for QAY125 Ton Automobile Crane

Driving axle loader is a key component for loader. For the steering drive axle of the QAY125 all terrain crane, the main parameters of the main reduction gears and drive axle housing have been designed and calculated. By adopting the method of optimum matching between engine and transmission system parameters, the ratio of the main reducer is determined by the optimum design. Considering the drive axle housing structure and the force is very complex, in order to ensure the strength of full static strength check calculation of impact load and emergency braking of the three cases, calculations show that the axle strength design can meet the design requirements. The half shaft diameter is calculated by using the maximum torque, when the half shaft diameter is 45mm, the material selection 42CrMo, the half shaft safety factor is 2.09, completely meet the use requirements.

Classifying and generating exact coset representatives of PGL 2 ( F q ) in PGL 2 ( F q 2 )

Generating coset representatives of PGL 2 ( F q ) in PGL 2 ( F q 2 ) is a key ingredient in certain algorithms of determining primitive elements and computing discrete logarithms in finite fields of small characteristic. In this paper, we describe a simple classification of the right cosets of PGL 2 ( F q ) in PGL 2 ( F q 2 ) . Based on the classification, we design a deterministic algorithm that generates the exact coset representatives of PGL 2 ( F q ) in PGL 2 ( F q 2 ) with O ( q 3 ) field operations.

On orders in number fields: Picard groups, ring class fields and applications

We focus on orders in arbitrary number fields, consider their Picard groups and finally obtain ring class fields corresponding to them. The Galois group of the ring class field is isomorphic to the Picard group. As an application, we give criteria of the integral solvability of the diophantine equation p = x2 + ny2 over a class of imaginary quadratic fields where p is a prime element.

Primality test for numbers of the form A p n + w n

We propose an algorithm for determining the primality of numbers M = A p n + w n where w n p - 1 ? 1 ( mod p n ) and A < p n and give example when p = 7 . The pth reciprocity law is involved. If p is viewed as a constant, the algorithm runs in O ( ( log ? M ) 2 ( log ? log ? M ) 3 ) bit operations. Our results and those of P. Berrizbeitia et al. 7,6] resolve an open problem proposed by F. Lemmermeyer in 2000 15].

Study on Demand Design and its Value Measurement of Automobile Customer

On the basis of the demand hierarchy theory and through the questionnaire survey, the rational consumption demand characteristics of automobile customers were obtained in the paper. According to the research objectives, and taking Huai’an automobile consumption market for example, the results of statistical analysis with the investigation content of age, income and career were given out. After establishing the value statistics model based on customer demand, and taking automobile insurance for instance, using the multivariate linear regression method and going through F checkout, the linear quantitative relationship between automobile insurance and automobile age, family income, the cost of buying an automobile was obtained, and the results were analyzed. A large number of sample statistics indicated that the service value link mainly was the link of automobile insurance, beauty decoration and maintenance.

SIGSO Satellite Tracking Characteristics of Large-Diameter Parabolic Antenna

SIGSO satellite is a special kind of geosynchronous orbit communications satellites. Its orbit height is the same as geostationary orbit, but its inclination varies periodically and annually, with variation in the range of 0 ° to 15 °. When communication master station uses large-diameter antenna tracking SIGSO satellites, only a fraction of 1 degree of the antenna beam width is relatively small along with its inclination becomes bigger. Then which kind of tracking mode should be selected to keep precisely pointing to the SIGSO satellite becomes a very important issue. This paper takes Apstar-1 satellite as an example to analyze SIGSO satellites motion characteristics. Pros and cons of a 16-meter antenna with Truss-step tracking Apstar-1 satellite were studied and actual measurement was carried out in Beijing. Finally, mono-pulse tracking and turntable antenna mount is recommended which lays a good foundation for the system optimization design.