Papers by Keyword: Mechanism

Abstract: The paper concentrates on the material mechanism analysis of airliner landing onto water in slide decelerating stage. According to the solid material, the difference equation is constructed to find the posture of airliner with different angles Our numerical results show that the impact of stormy wave may make airliner out of balance, impact acceleration is inversely proportional to the sliding distance, .

Abstract: Based on the analysis of geological data and meteorological data of landslide, the mechanism of rainfall-induced landslides was analyzed, and the relationship between landslide and rainfall was further discussed, including the landslides and rainfall distribution, the relationship between landslide and frequency of rainstorm, and the time relationship between landslide and rainfall. The results show that the probability of landslide occurrence and the quantity of landslides have positive correlation with rainfall. The landslides mainly occur from May to September in which the monthly mean rainfall is large. Meanwhile, landslide occurrence is closely related to the characteristics of rainfall of that day and rainfall of early days. When the daily rainfall exceeds 50mm or 10 days accumulative rainfall exceeds 100mm, the landslide is prone to occur and the occurrence rate of the latter is higher.

Abstract: Due to the particularity of the ancient city wall, the collapse damage of ancient city wall earthen ruins is different from general soil slope failure. Through on-site observations and theoretical analysis, collapse failure process and mechanism of ancient city wall earthen sites under the action of capillary water is studied, and protection measures are proposed. Collapse failure process of earthen sites under the action of capillary water has the characteristics of particularity, diversity and stage. Capillary water reduces the stability of ancient city wall by changing the soil physical properties, chemical and ice split role. Finally, the effect of capillary water is illustrated through a specific project example.

Abstract: This paper suggests the mechanism of occurrence of debris flow in mountain streams. It is found that the sliding of the undermined stream banks follows the exponential probability distribution function. This indicates that the major amount of debris is from an intensive sliding in the initial stage of flood flow development. This can be otherwise proved by the viscous flow boundary layer theory such as the shear stresses on the wall are initially very large. Through a relative dimensional analysis, a special dimensionless parameter K is grouped which has a very important effect on the occurrence of the acceleration of the heavy debris by the flow. It interprets, during the flood flow development, the amount of debris on the stream bed can only be accelerated when the kinetic energy of the flow is greater than the apparent work of the debris against the flow. Of course, as a transient behavior, once it starts, the sudden acceleration of a huge amount of debris flow bore will usually cause an unpredictable downstream disaster.

Abstract: Moderately thermophilic bioleaching of a pyritic chalcopyrite concentrate was mimicked in an electrochemical vessel. The bioleaching was carried out for 28 days at 45°C with 2.5% (wt/vol) solid content at pH 1.5. Data from the redox potential development was used to program a redox potential controller in an electrochemical vessel to reproduce the same leaching conditions in the absence of microorganisms. Despite precipitation of iron as jarosite and formation of elemental sulphur in the electrochemical experiment, the copper recoveries were almost the same in both experiments.

Abstract: Sodium calcium borate glass derived hydroxyapatite (G-HAP) scaffolds were prepared by dipping with polymer foam. The effects of adsorption time and G-HAP scaffolds dosage on adsorption performance were studied. The results showed that G-HAP scaffolds could remove fluorine ions in solution effectively. The mechanism of G-HAP scaffolds in removing fluorine ions from aqueous solutions was investigated by the X-ray diffraction, Infrared Spectra and Scanning electron microscopy-Energy Dispersive Spectrometer.

Abstract: The friction and wear properties of the water lubricated rubber bearing, made of the nitrile butadiene rubber (NBR), were studied in this article. The results showed that adding the appropriate amounts of carbon black and molybdenum disulfide (MoS₂) could reduce the friction coefficient and the abrasion loss to the minimum values. Meanwhile, the general laws of the two parameters with different loads, rotational speeds and lubricant media have been discovered: the values of friction coefficient and abrasion loss of the rubber bearing, lubricated in both water and seawater, increase firstly and then gradually decrease with the increasing loads.When the loads exceed 500N, the values increase drastically. And the values of friction coefficient and abrasion loss decline with the increasing rotating speed. Moreover, the values of these two parameters in seawater were a little bit higher than those in water. The friction and wear mechanisms of water lubricated rubber bearing were also discussed..

Abstract: Upper limb fracture is easily found in the truck-to-pedestrian road traffic accident. And it is important to understand and elucidate the biomechanics of upper limb fractures caused by the frontal structure of the truck. Finite element (FE) analysis could potentially help in the understanding the biomechanical response mechanism of upper limb fracture. In this study, THUMS (Total Human Model for Safety) was applied to reconstruct the upper limb fracture in a real-world truck-to-pedestrian accident. Totally two FE simulations were conducted to find out the most likely scenario in this case. Analyzing the simulations of two possible scenarios clearly demonstrated that the simulation result of collision-to-left scenario was consistent with the autopsy finding, and bending mechanism could explain how the upper limb fracture occurs. Then we drew a conclusion that FE analysis is a valuable method for us to understand the biomechanical mechanism of upper limb fracture in the forensic practice.

Abstract: Complex analytical method is employed to study the motion of a kind of mechanism. The angular velocities and the angular accelerations of the connecting rod and the rocker are deduced. The motion trajectory and linear velocity of a key point are also given. The results of the given example show the feasibility and the effectiveness of the method and conclusions here.

Abstract: First, heuristic clustering method based on local information is introduced, second, the label propagation method based on local information is summarized, and then problem of the iterative process and a random strategy to select a node that belongs to the cluster structure are analyzed. Label propagation algorithm base on the similarity of node attributes is improved. At last, the experiments are used to help discover the efficient and availability of the algorithm, and put the algorithm into preliminary application.