Bundled Hybrid Offset Riser Global Strength Analysis

Bundled hybrid offset riser (BHOR) global strength analysis, which is more complex than single line offset riser global strength analysis, was carried out in this paper. At first, the equivalent theory is used to deal with BHOR, and then its global strength in manifold cases was analyzed, along with the use of a three-dimensional nonlinear time domain finite element program. So the max bending stress, max circumferential stress, and max axial stress in the BHOR bundle main section (BMS) were obtained, and the values of these three stresses in each riser were obtained through the "stress distribution method". Finally, the Max Von Mises stress in each riser was given and a check was made whether or not they met the demand. This paper provides a reference for strength analysis of the bundled hybrid offset riser and some other bundled pipelines.

Preliminary analysis of mode truncation of single-layered reticulated domes under earthquakes

In anti-seismic calculation, the mode truncation is a significant problem to engineers if the mode-superposition response spectrum method is used, which has not been completely solved yet in some large and complex structures such as reticulated domes. In this case, some useful advices, concentrating on the problem above, are expected through a careful and comprehensive investigation of this paper. During the investigation, the authors first point out shortcomings of former researches. Then frequency-spectrum characteristics of single-layered reticulated domes were studied from the perspective of structural responses. During this process, some important results such as the existence of the main resonant section, and the fact that the relative sensitivity of these domes under horizontal and vertical impulse varies with the different R/S ratios were achieved. Furthermore, based on the study of frequency-spectrum characteristics, as well as that of earthquake input, reasonable numbers of mode truncation in single layered reticulated domes with different R/S ratio were presented. Results of case studies prove the mode truncation number proposed is valid.

Anatomical Study an the Development of Strawberry Fruit

The development of strawberry fruit, two cultivars-Gelila and Xiaoshi, was systematically studied by anatomical and embryological methods. The growth dynamics of fruit showed that the two cultivars performed similar changes with their fresh weight volume and structure, it included the first slow growth stage, the rapid growth stage and the second solw growth stage. The fruit was a typical polyachene with a ovule which belonged to a Poligonum type, the growth process of pollen tube from stigma to embryo sac was clearly observed by flourescence microscopy. Embryo development was similar to that of most dicotyls, and the mature embryo was orthotropous; Endosperm development was a nuclear type, and gradually disappeared with development:Seed coat consisted of 34 layer cells, and pericarp was composed of 68 layer cells which differentiated from ovary wall cell; The structure of receptacle was a typical stem which consisted of epidermis ,cortex and vascular cylinder. With development, the cortex an