Depending on how the ground surface is denuded , the feature of the current crustal stress field and rock stress environment can be calculated analyzing the result in this paper : by analyzing the recovering feature of the elastic deformation of the rockmass in unload - stage under various pressures , it has been found there is close relationship between the recovering degree of the elastic deformation of the rockmass and the unloading degree of the pressure the direction of the major principal stress in the crustal stress field is not consistent with the direction of the crushing stress regional tectonics borne during the last tectonic movement . the evolving degree of the regional geomorphology evidently affects the current crustal stress field , which changes from the self - weight stress field to the horizontal stress field , with the changing of the eroding degree of the regional geomorphology ranging from valley area to hilly country to flat country . in valley area , where there is two stress belts , the bankslope s tress belt and the self - weight stress belt within the mountain . the direction of the major principal stress is nearly parallel to the ground surface and inclines towards the valley in the bankslope stress belt . it is nearly vertical in the self - weight stress belt 通过本文的研究成果，根据区域性地貌的演化特征，我们可以大致地对现今地应力场进行判断：在分级卸荷条件下，岩体中弹性变形的恢复具有明显的规律性，这种规律对于研究地应力场的演变是有帮助的；地应力场中最大主应力方向与区域构造形迹在最近的构造运动中所受区域性挤压应力的方向无明显的对应性；区域性地貌形态的演化程度对现今地应力场的特征具明显的影响，随着区域性地貌侵蚀程度由峡谷区、丘陵区、平原区的变化，现今地应力场特征由自重应力场、水平应力场为主含少量自重应力场特征向水平应力场的规律变化；在峡谷区，山体中具有两个应力带：自重应力带和卸荷应力带，最大主应力方向在卸荷应力带中近平行于坡面并倾向于河谷、在自重应力带中近于直立；根据原始地面遭剥蚀的程度，可以大致地估算最大主应力和中间主应力的量值和方向；在丘陵区和平原区，最大主应力的方向近于水平，并与附近区域性侵蚀盆地和河流的展布方向基本平行，根据原始地面遭剥蚀的程度，可以大致估算其最大主应力的量值；根据区域性地貌形态的特征来分析工程区的现今地应力场特征，并进而大致了解岩石的应力环境，这种分析方法得出的结论与许多实际的地应力测试成果基本一致，对于大型水电工程地下厂房和压力隧洞的设计是有所帮助的。
Fluid machinery in these areas is damaged due to cavitation and sand abrasion , which has threaten directly the safety operation of hydraulic and hydroelectric engineering , causing huge economic losses . the research , therefore , on the combined effect of cavitation and sand abrasion is of great significance . the researchers at home and abroad have done a lot of work on this issue 我国许多河流的含沙量较大，如著名的黄河干流年均含沙量达37 . 9m ~ 3 / s ，黄河三门峡的年平均输沙量达16亿t ，这些地区使用的泵、水轮机等许多流体机械都在夹沙水流的作用下，受到了沙粒磨损与空化剥蚀的联合破坏，这种破坏直接危害了水利水电工程的安全运行，造成了巨大的经济损失，因而对含沙水流条件下空化剥蚀与泥沙磨损联合作用进行研究有着很大的工程实际意义。
The variations of the surface state and environment conditions could change the procedure of exfoliation , therefore , the potentiometry and electric resistance methods in this paper are used to measure the exfoliation rate of aluminum alloys in a constant temperature , the experimental results show that relations of natural corrosion potential vs time have a resemblance to those of corrosion rate vs time , both relations are all at the different change rates in the front and back of 120 minutes 超硬铝合金表面状态、环境条件的变化，均可能改变剥蚀的发展过程，为此，本文提出在恒温条件下，用电位法、电阻法定量研究铝合金的剥蚀性能。实验结果显示了lc4cs铝合金的自腐蚀电位与时间的关系，和腐蚀速率与时间的关系有着十分相似的规律，两者均在120分钟前后有不同的变化。
