THREE-DIMENSIONAL INTERACTIONS OF A HALF-PLANE CRACK IN A TRANSVERSELY ISOTROPIC PIEZOELECTRIC SPACE WITH RESULTANT SOURCES

Exact solutions in elementary functions are derived for the stress and electric displacement intensity factors of a half-plane crack in a transversely isotropic piezoelectric space interacting with various resultant sources, including force dipole, electric dipole, moment, force dilatation and rotation. Such force and charge sources may model defects like vacancies, foreign particles and dislocations. The locations and orientations of the stress and charge sources with respect to the crack are arbitrary.

The analysis of epidemiological characteristics of road traffic crashes in a mountain city in western China

Objective: To study the epidemiological characteristics and preventive methods of road traffic crashes in a mountain city in western China through sampling investigation of traffic crashes in different regions of Chongqing city in recent years. Methods: Two police teams of traffic management in downtown, two teams in suburb, one team in county and one freeway team were randomly selected, and road traffic crashes between 1988 and 1997 were investigated and analyzed. Results: A total of 13121 road traffic crashes with 6201 crashes with casualties were analyzed. The incidence of crashes was higher in May, June and July, and on Friday and Wednesday and at 8:00-12:00 and 14:00-18:00 within a day. Casualties were 44.0% in pedestrians and 42.5% in passengers of total casualties. The deaths and severe injuries in pedestrians were 59.1% of total deaths and 56.4% of total severe injuries. The age of drivers and passengers were mainly at 18-30 years, followed by 31-40 years. People over 60 years old accounted for 24.1% of total pedestrian casualty. Head injury was the most common reason for deaths. The main reasons for these crashes were improper driving and violating traffic laws. Violating traffic laws by pedestrian was one of the main reasons for pedestrian casualty. Conclusions: The crashes are related to the characteristics of geography, climate, society activity of people, and the sense of traffic safety, the basic traffic construction and management in Chongqing. The traffic casualty of pedestrian is a big problem in Chongqing. To prevent and decrease road traffic injuries effective methods should be worked out and propaganda on traffic safety and traffic management should be strengthened according to different characteristics of different regions. To strengthen the first aid and treatment of cranium-brain injury and chest-back injury is also helpful in decreasing traffic deaths.

Road crash in China from 2003 to 2005

对分析特征和在从 2003 ～ 2005 的中国的道路碰撞和损害的原因客观。在 2003-2005 的道路碰撞的数据被收集学习包括的特征的方法总计车辆数字，交通事故的出现率和严重交通事故以便在中国讨论道路碰撞的原因和特征。每 100 000 个人并且每 10 000 车辆的从 2003 ～ 2005 的结果，交通事故的数字，损害和死亡以及死亡率在中国衰退了。直到 2005，交通事故的全部的数字减少了到 450 000 并且死亡到 99 000，每 10 000 车辆与死亡率是 7.6 个人。当司机和旅客在 2005 分别地说明了 33.2% 死亡伤亡和 26.6% 时。最交通的事故被司机引起，特别那些与不到 3 年驾驶经验。交通事故发生在郊外的道路上占了 60% 。交通事故的死亡率每第一条等级道路上的 100 km 评价最高。高速公路上的交通事故的死亡率评价最高，随死亡和损害的不断的增加。结论目前，在中国的交通事故和 casualities 的增加趋势被减慢了到某程度并且证明一个衰退趋势，而是状况是远的离开是乐观的。为了切，击倒交通事故和伤亡的数字，我们应该对与不到三开车的年和那些开车总线训练并且设法驱动程序给予更多的注意。严格的预防措施应该在改进急救系统上象改进一样在第一条等级道路，高速公路和郊外的道路上在交通事故上被生。