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Compared with each other of existed schemes and effects of the waterway regulating with complex shoals, from the viewpoint of water-sediment interacting evolutional properties and their effects on complex shoals of waterway, the results show that, the evolutional processes of channel morphology observe the principles of maximum entropy in equilibrium state and minimum entropy production rate in non-equilibrium state, in energy words, it is the minimum energy dissipation rate. The vortex moving dominates the sediment transport. From the practical engineering viewpoint, the general criteria for waterway regulating with complex shoals were investigated, the results may be valuable to regulating study of the mountain rivers.

Being closer space among steep and close seams, there always is a mutually destructive influence on adjacent seams while mining arbitrary coal seam within the same mining section, so the scientific mining method of steep and close seam is always the difficult problem to mining workers. Urumchi coalfield developed by Shenhua Xijiang corporation is a very few mine in China and even the world, in which entirely existing and exploiting steep and close seam. There are more than 30 layers of steep seams with different thickness and different distance. Aiming to the steep and close seams in Jiangou coalmine of urumchi mine, the combining mining methods with different mining approaches and different advancing distances were numerically simulated using 2-D and 3-D Finite Element Method, the deformation and failure features of surrounding rock were studied, and then the scientific of combining mine in steep and close seam was investigated.

One of the main content of the environmental geotechnical engineering is engineering disaster problem brought by environmental change, the most basic problem is the influence of occurrence environment on the mechanical properties of rock. The water-saturated and freeze-thaw cycling experiment were conducted for dried shale under the open system, then carried out the mechanical properties experiment on dry and water-saturated state and on certain times of freeze-thaw cycles, the characteristics of the water softening, freeze-thaw damage deterioration, deformation and failure for shale were studied systematically. It is shown that the moisture has an important impact on mechanical effect of shale. With the increasing of the freeze-thaw cycles, the elastic modulus and strength of the shale reduce significantly, then approach stably after experiencing a certain number of freeze-thaw cycles, while the ultimate strain is increasing continuously. The engineering problems brought by environmental change must be solved from moisture and temperature in geotechnical engineering in cold regions.

In the coal mine of Huaibei Mining Area, based on the character of thick dirt band in the coal seams and the influences to top coal caving, the physical and mechanical properties of dirt band were analyzed. In order to improve the recovery rate of top coal, the failure mechanism of dirt band was analyzed through the cantilever beam model, and the sensitivity analysis to the length of dirt band overhang was done in the conditions of different mining height and dirt band thickness. The results show that, the average water absorption of dirt band samples is 3.5%, and the soften coefficient is 0.71, which presents that the dirt band have large softening property and poor engineering geological property. When the thickness of dirt band was more than 3.5 m, the top coal could not be caved smoothly. However, the bigger underground pressure would be helpful to the broken of dirt band and top coal seams, and the recovery rate of top coal was improved.

From the viewpoint of vortex dynamics, the flowing properties and the characters of transition from laminar flow to turbulent flow were analyzed, the concept of the Reynolds number was reviewed and studied. The different form of the Reynolds number was presented to relate it with fluctuating and breaking down processes to show its dynamical mechanism. On the basis of phenomenological properties, the velocity distribution near the wall was studied to show that the profile connects with the flowing structure which is different from the linear form what usually considered to be, thus the velocity distribution near the wall remains open. Finally, the form of the velocity distribution should follow was probed.

While transmission theory of asymmetric double circular arc gears is created,the design parameters of asymmetric double circular arc gears are also studied theoretically in this paper. A set of equations for determining asymmetric double circular arc tooth profile are deduced. The theoretical foundation will be laid for designing the gear pumps and reduction boxes in the future productively.

The core of ultrasonic accelerate fatigue test is resonance, and specimens need resonating with the system. The ultrasonic fatigue test method was used to investigate the high cycle fatigue properties of LZ20Mn2 axle pipe steel. Tests were conducted on cylindrical dog-bone specimens, and all fatigue loadings were controlled by inputting vibration amplitude. The results showed that the S-N curve of LZ20Mn2 axle pipe steel presented a slow-decline shape and subsurface crack initiation. The fatigue fracture was observed by SEM. Two different crack initiation mechanisms were observed which were the mixed inclusions and dislocation. Crack closure effect played an important role at fatigue crack propagation area and the fracture mechanism was a typical plastic fracture.