Advanced Materials Research Vols. 317-319

Abstract: In view of actual situation of serious resources waste and less than 30% of face recovery ratio to shallow seams with existing features of harder roof at the process of room and pillar mining in northern Shaanxi province in China, reasonable support strength has been studied in both cases of normal mining and force caving for improved longwall mechanized mining face, and obtained reasonable working support resistance at the condition of force caving which was better than normal mining. Based on this condition, Shandong Xin Mei machinery Co, Ltd. has developed hydraulic support with hanging chain and splicing beam which was suitable to existing features of shallow seams. The support had advantages with flexible connection between supports to ensure that all pillars reached rated setting load, sub-size top beam to resolve "protection" and "cutting" dilemma for the roof, adjusting and locking support, etc. The company also has given concrete support parameters. By the field industrial test verification, the developed new support fully adapted strata behavior at the process of force caving with existing features of shallow depth and harder roof. The research has provided a useful reference for other coal mines with similar geological features.

Abstract: This paper, according to the principle of the Hershcel-Quincke tube, presents a semi-active silencing device which can effectively control the fundamental frequency exhaust noise of the internal combustion engine. This device can choose the proper pipeline by using the valves to achieve semi-active control of low-frequency noise of the internal combustion engine. Taking the 4102BG-type diesel engine as the research object, we designed a bypass duct silencer to control its fundamental frequency exhaust noise, and then simulation and steady-state control performance testing also have been done. The results show that the bypass duct silencer can get 6~20dB reduction of the fundamental frequency exhaust noise in the steady-state operating conditions, and the total SPL has also decreased.

Abstract: An inpainting method is proposed to restore the image containing some missing patches. Based on the spartity of images, the method translates the problem of image inpainting into image reconstruction in compressed sensing. The inpainting model is solved using the split iteration. Simulated image inpainting results demonstrate the efficiency of the proposed method.

Abstract: Based on the present tecnology of pile, a method of compacted forming concrete pile applied in the subsea base is studied. Using the method of finite different the procedure of compacted forming at the end of steel pipe pile has been simulated in the particular geology soil, the effects of the elastic modulus, cohesion, friction and dilation on the compacted behaviour are aquired and the bearing capacity has been calculated. The results show that the ultimate bearing capacity of this pile increases approximate 3 times bigger than the steel pipe pile with the same dimentions, in addition, its curve of Q-S is smooth and ultimate feature point is indistinct, which proves that this tecnology of compacted forming concrete pile is able to increase the bearing capacity prominently.

Abstract: On the basis of analyzing process and structure characteristics of branch shape water-injection pipe network, this paper established a hydraulic calculation method of branch shape water-injection pipe network based on binary tree. This method has many advantages, such as calculation speed is fast, occupying less memory, having high calculation accuracy, and so on. According to it, this paper compiled a computer program and presented an actual example.

Abstract: Considering frequent braking characteristics in working process of the Underground Loader, a braking energy recovery scheme for Underground Loader is put forward, on this basis, a corresponding mathematical model is established. Moreover, simulation study in MATLAB/Simulink on the three key parameters (accumulator volume, charge pressure and hydraulic pump discharge) which affect the efficient of energy recovery are carried out. At last, several key parameters of braking energy recovery scheme of Underground Loader are optimized basing on Man-Machine Engineering.

Abstract: Gyrocompass is an important instrument which provides course to vessels, but its complex three-dimensional structure and principle of pointing towards the North is a bottleneck of studying gyrocompass. The master compass of Anschütz 4 gyrocompass are simulated by virtual reality modeling language VRML, so that using three-dimensional interactive to show the structure of the gyrocompass and the work principle is implemented and learners will have a direct cognition to each part of the gyrocompass and its work principle. The realization process of simulation in the virtual reality environment is described in detail and the relevant source codes is given.

Abstract: The Aerodynamic noise, which is generated by the moving vehicle at high speed, is a kind of broadband noise. This paper dwelled on the Ligthill’s Acoustic Analogy firstly, and applied the realizable k-ε turbulence model to simulate the external steady flow field of automobile, so as to get the distribution characters of statistical turbulence quantities based on the Reynolds-averaged Navier-Stokes (RANS) equation. Then the Curle’s Integral in Broadband Noise Source Models was utilized to predict the local aerodynamic acoustic power contribution on automobile’s surface, which is helpful to the farther research work in the vehicle body optimization design based on aerodynamic noise controlling. The results shows that: The aerodynamic acoustic power contribution regions on surface mainly distribute near the automobile’s head and tail; and the maximum SAPL (Surface Acoustic Power Level) value is up to 83.15 dB in the vicinity of the rear wheel hub when the vehicle speed is 120km/h; the higher the speed of automobile, the more scattered the distribution of main aerodynamic acoustic power on automobile’s surface.

Abstract: In recent years, China has focused on the research of energy reuse and environmental protection with lots of manpower and financial capacity. And we have already gotten results on many aspects from transportation to factory production. In this paper, we will think about energy reuse from a new perspective: recovery and reuse of heat energy of human body. This paper researches and analyses the feasibility of thermal energy recovery for the shanghai railway station.

Abstract: This article records the measuring of applied force exerted on plate structure by sea wave only, and observation of the regular pattern of the stress under stimulated conditions of ocean in the lab. And calculating of the applied stress on plate structure through MATLAB then integrating of the stress diagram using wave pressure formula, as well as comparative analysis of the two groups of data using selected wave theories.