目的:评价冷刺激口腔对重症监护室(ICU)病人口渴的效果。方法:计算机检索the Cochrane Library、PubMed、EMbase、Web of Science、中国知网、万方数据库、维普数据库、中国生物医学文献数据库中关于冷刺激口腔对ICU病人口渴效果影响的...目的:评价冷刺激口腔对重症监护室(ICU)病人口渴的效果。方法:计算机检索the Cochrane Library、PubMed、EMbase、Web of Science、中国知网、万方数据库、维普数据库、中国生物医学文献数据库中关于冷刺激口腔对ICU病人口渴效果影响的随机对照试验,检索时限为建库至2022年10月1日。经2名研究者筛选文献、提取信息与质量评价后,采用RevMan 5.3和STATA软件进行Meta分析。结果:最终纳入8篇文献。Meta分析结果显示,冷刺激口腔能降低ICU病人口渴强度[MD=-2.12,95%CI(-3.12,-1.11),P<0.00001],缓解ICU病人口渴痛苦感[MD=-2.15,95%CI(-3.85,-0.46),P=0.01],提高口腔黏膜湿润程度[MD=-0.78,95%CI(-1.37,-0.20),P=0.009]。结论:现有证据表明,冷刺激口腔能有效降低ICU病人的口渴强度,缓解ICU病人口渴痛苦感,改善ICU病人口腔黏膜湿润程度,提高病人在ICU治疗期间的舒适度。展开更多
Aim The general arbitrary cracked problem in an elastic plane was discussed. Methods For the purpose of acquiring the solution of the problem, a new formulation on the problem was proposed. Compared with the classic...Aim The general arbitrary cracked problem in an elastic plane was discussed. Methods For the purpose of acquiring the solution of the problem, a new formulation on the problem was proposed. Compared with the classical plane elastic crack model, only the known conditions were revised in the new formulation, which are greatly convenient to solve the problem, and no other new condition was given. Results and Conclusion The general exact analytic solution is given here based on the formulation though the problem is very complicated. Furthermore, the stress intensity factors K Ⅰ, K Ⅱ of the problem are also given.展开更多
The conservation law of J-integral in two-media with a crack paralleling to the interface of the two media was firstly proved by analytical and numerical finite element method. Then a schedule model was established th...The conservation law of J-integral in two-media with a crack paralleling to the interface of the two media was firstly proved by analytical and numerical finite element method. Then a schedule model was established that an interface crack is inserted in four media. According to the J-integral conservation law on multi-media, the energy release ratio of Ⅰ-type crack was considered to be conservation when the middle medium layers are very thin. And the conservation law was also convinced by numerical method. By means of the dimension analysis on the model, the asymptotic results and formula calculating the energy release ratio and complex stress intensity factor are presented.展开更多
A mode Ⅲ crack problem in a transversely isotropic piezoelectric material subjected to uniform loads at infinity is studied based on exact boundary conditions. The complex potential approach is used to reduce the pro...A mode Ⅲ crack problem in a transversely isotropic piezoelectric material subjected to uniform loads at infinity is studied based on exact boundary conditions. The complex potential approach is used to reduce the problem to Hilbert problem. As a result, closed form field solutions in the piezoelectric material and inside the crack are presented. It is shown that the stresses and electric displacement have square root singularities at the crack tips, but the electric field is uniform everywhere in the material and equal to the remote applied one. It is also found that the electric displacement intensity factor depends on both material properties and the mechanical loads, but not the electric loads. Hence it may be concluded that the electric loads have no influence on the field singularities.展开更多
Within the framework of nonlinear eleetroelasticity, the stress field near to the crack tip in an infinite piezoelectric media subject to a far field uniform loading is studied by using an electrical strip saturation ...Within the framework of nonlinear eleetroelasticity, the stress field near to the crack tip in an infinite piezoelectric media subject to a far field uniform loading is studied by using an electrical strip saturation model and the complex variable method. And the emphasis is placed on the stress field near to the crack tip. The obtained solutions show that the normalized stress components at an arbitrary point near to the crack tip are determined by the angle of the point. Moreover, the stress components are independent of the distance from the point to the ori- gin of the coordinate. The distributions of in-plane stress components near to the crack tip are analyzed based on numerical results for PZT-SH. Compared with some related solutions, results show that the solutions are valid.展开更多
文摘Aim The general arbitrary cracked problem in an elastic plane was discussed. Methods For the purpose of acquiring the solution of the problem, a new formulation on the problem was proposed. Compared with the classical plane elastic crack model, only the known conditions were revised in the new formulation, which are greatly convenient to solve the problem, and no other new condition was given. Results and Conclusion The general exact analytic solution is given here based on the formulation though the problem is very complicated. Furthermore, the stress intensity factors K Ⅰ, K Ⅱ of the problem are also given.
文摘The conservation law of J-integral in two-media with a crack paralleling to the interface of the two media was firstly proved by analytical and numerical finite element method. Then a schedule model was established that an interface crack is inserted in four media. According to the J-integral conservation law on multi-media, the energy release ratio of Ⅰ-type crack was considered to be conservation when the middle medium layers are very thin. And the conservation law was also convinced by numerical method. By means of the dimension analysis on the model, the asymptotic results and formula calculating the energy release ratio and complex stress intensity factor are presented.
文摘A mode Ⅲ crack problem in a transversely isotropic piezoelectric material subjected to uniform loads at infinity is studied based on exact boundary conditions. The complex potential approach is used to reduce the problem to Hilbert problem. As a result, closed form field solutions in the piezoelectric material and inside the crack are presented. It is shown that the stresses and electric displacement have square root singularities at the crack tips, but the electric field is uniform everywhere in the material and equal to the remote applied one. It is also found that the electric displacement intensity factor depends on both material properties and the mechanical loads, but not the electric loads. Hence it may be concluded that the electric loads have no influence on the field singularities.
基金the Innovation Project for Graduates in Jiangsu Province~~
文摘Within the framework of nonlinear eleetroelasticity, the stress field near to the crack tip in an infinite piezoelectric media subject to a far field uniform loading is studied by using an electrical strip saturation model and the complex variable method. And the emphasis is placed on the stress field near to the crack tip. The obtained solutions show that the normalized stress components at an arbitrary point near to the crack tip are determined by the angle of the point. Moreover, the stress components are independent of the distance from the point to the ori- gin of the coordinate. The distributions of in-plane stress components near to the crack tip are analyzed based on numerical results for PZT-SH. Compared with some related solutions, results show that the solutions are valid.
