ABSTRACT
A hybrid simulation method is introduced and used to study two-dimensional single-asperity and multi-asperity contacts both quasistatically and dynamically. The method combines an atomistic treatment of the interfacial region with a finite-element method description of subsurface deformations. The dynamics in the two regions are coupled through displacement boundary conditions applied at the outer edges of an overlap region. The two solutions are followed concurrently but with different time resolution. The method is benchmarked against full atomistic simulations. Accurate results are obtained for contact areas, pressures, and static and dynamic friction forces. The time saving depends on the fraction of the system treated atomistically and is already more than a factor of 20 for the relatively small systems considered here.
ABSTRACT
A retrospective investigation of 1,079 patients with gastric cancer among 181,055 patients in a general hospital showed that 0.59% of all the ward patients suffered from gastric cancer (6:1, male preponderant) , with the age ranging from 41-70, and the peak age was between 50-60. Most (98.24%) were progressive, others (1.76%) were early gastric cancers. Many of the patients with clinical courses over 1 year before hospitalization had histories of gastropathy. Pathological examination of the early gastric cancers showed that the cancers in 15 (78.94%) out of 19 patients were due to malignant change of ulcers. However, our results were not quite similar to previous reports in the distribution, limit, number and microscopic classification of the lesions. There was no obvious discrepancy in lesion display and diagnostic accuracy among the three methods, e.g., regular examination, double contrast examination, and the endoscopy examination (P greater than 0.05). The accuracy of diagnosis might be improved by using multiple examinations of stomach and combination of gastrointestinal examination with endoscopy.
