Twin and dislocation mechanisms in tensile W single crystal with temperature change: a molecular dynamics study.

Molecular dynamics simulations are performed to investigate the orientation and temperature dependence of tensile response in single crystal W. It is found that W single crystal exhibits distinct temperature-dependent deformation behaviors along different orientations. With increasing temperature, the yield strain in the [001] orientation increases, while those in [110] and [111] orientations first increase and then decrease. The tensile deformations along orientations close to [001] are found to be dominated by twinning; the nucleation and growth of twins are accomplished through the nucleation and glide of ⅙111 partial dislocations on {112} planes. In contrast, the deformations along orientations close to [110] and [111] are found to be dominated by the slip of ½111 full dislocations, which move in a stay-and-go fashion. Moreover, intermediate deformation behaviors, which may become unstable at high temperatures, are observed for some intervening orientations. The distinct deformation behaviors of W along different orientations are rationalized based on the twinning-antitwinning asymmetry of ⅙111 partial dislocations on {112} planes.

Nurses' knowledge and attitudes on comfort nursing care for hospitalized patients.

To investigate the knowledge and attitudes of practicing nurses on comfort care for hospitalized patients, a survey was conducted in 311 registered nurses from a major teaching hospital. A total of 212 (68.1%) of the participants showed an adequate knowledge of comfort care. Participants who had 6 years or more working experience returned a higher mean scores on physiological and psychological aspects of comfort care (P < 0.05). The total scores were the highest among participants from intensive care unit and the lowest among participants from the oncology department. Although 282 (90.7%) participants were involved in comfort care, only 210 (67.5%) received formal hospital-based training in this practice. We conclude that there was a large difference in the knowledge between nurses from different departments on comfort care. Continuing education programmes are required to improve the knowledge and skills in comfort care.