Advanced Materials Research Vol. 709

Abstract: Subjected to external pressure, buckling analysis is key problem in the roof shell design of large scale cylinder gasholder. Two simplified buckling analysis methods, the continuous orthotropic plate method and the split-rigidity method, are introduced to check the general instability of stiffened spherical shallow shell. Considering the plate and the stiffeners in two directions with the same contribution to the bending stiffness, the equivalent bending thickness formula is put forward. The finite element model for a 100,000 m³cylinder gasholder roof is setup. The buckling critical loads obtained prove that the split-rigidity analysis method and formulae are applicable. The results can be referred in design of stiffened spherical shallow shell.

Abstract: Effects of different methods of gas package on freshness of harvested waxy maize at room temperature in its shelf life were investigated. The harvested waxy maize were packaged under vacuum, air, N2 or CO2, respectively, and then stored 90 days at 30°Cafter the high temperature sterilization. After the sterilization and during storage, the changes of aerobic plate count, water content, soluble sugar content, and sensory evaluation were determined. The results showed that compared with others, the package with N2 could inhibit the growth of microorganisms, kept the content of water, soluble sugar and fat. After 90 days, the sensory evaluation could show that waxy maize of N2 package had better tasty and aroma.

Abstract: Identifying the concentrated runoff channel is critical to prevent groundwater in mining area with karst water. In Fankou mining area, seven groups of high precision tracer tests were carried out using GGUN-FL30 and GGUN-FL20 field fluorescence, to identify concentrated runoff channels. The results indicated that the largest concentrated runoff channel of karst water distributed along the f1 and f2 faults; the second largest concentrated runoff channel of karst water distributed among the E-F curtain; the third concentrated runoff channel of karst water distributed among the H-I curtain; and the F-G-H curtain has good water plugging effect.

Abstract: The lunar exploration manipulator is an important part of lunar rover, which is also an important tool for the exploration of the moon. This paper simplifies the lunar exploration manipulator into two arms manipulator, which has three joint activities. Then analyze the motion of the manipulator to get the motion equation by the method of D-H, and also analyze the motion equations with the lunar rover base has a declination. In order to verify the correctness of the motion equations, the paper used the ADAMS software to simulate the motion of the manipulator.

Abstract: According to the gas explosion theory and the investigation of occurred gas explosion, the basic events that lead to coal mine gas explosion are summarized and the fault tree is worked out. Besides, the fault tree analysis is used for qualitative analysis. The minimal cuts sets, minimal path sets and structure importance are solved. Accordingly, the reasons of gas explosion are obtained, which can provide references for the prevention of coal mine gas explosion. The study showed that: the minimal cut sets of gas explosion is much(165) and the minimal path sets is small(4), and it is the major dangerous and harmful factors in coal mine. It that gas concentration must be strictly controlled and all sources of ignition should be eliminated is the basic and fundamental way to prevent mine gas explosion.

Abstract: In this work, we proposed a new calibration of piezoelectric phase-shifter using probability analysis based on Two-dimensional Fourier transform profilometry (2-D FTP). We tested the surface of the object under the noisy condition using the newly designed simulation system. It is found that both the relative and the absolute error are much less than those from the traditional method.

Abstract: This paper depicts the system design of an automatic golf collection robot. The robot is an intelligent system that consisted of three modules: the hardware module includes the mechanical structure and the electrical system; the control module processes the signals from the multiple sensors and outputs the instructions to navigate the robot; the vision module is used for recognition the golf balls from the grass background. The robot has been tested on the driving range, the basic functions of the robot have been achieved. The golf collection robot supersedes the human labor and shows a good application prospect.

Abstract: In this work a new perspective of pumping unit intermittent pumping intelligent control in strippers is presented. The strategy consists in associating economic situations and dynamometer cards analysis in a cascaded control. In the proposal, the widely applied control strategies based on dynamometer cards and downhole pressure modeling and the overall economic efficiency, since the development of pumping unit operation mechanism plays a vital role to ensure energy saving in low-volume wells. The simulation results are analyzed in order to evaluate the operational conditions propitiated by intermittent pumping control in actual operation.

Abstract: Because of its advantage of zero casualties, Unmanned Aerial Vehicle (UAV) plays an important role in battlefield monitoring and information acquiring, thus caught great attention of the world. But with large quantities of UAVs equipped, uncertain life-span has become an important constraint of operating UAV safely and economically. So assessing the service life has important military and economic values. In the entire UAV system, the airframe life severely affects operation of UAV. According to method of damage coefficient, evaluation model on life of UAV airframe was established. In the case of security, its fatigue life was determined.

Abstract: Power transmission tower is an important part of power transmission equipment. The tower foundation is suffered by landslides, debris flows, erections of foundation settlement and so on. The power transmission tower near Yanjin transformer substation is selected to be measured. By using fiber Bragg grating (FBG) earth pressure sensor, the earth pressure of tower foundation is measured. The long-term monitoring data indicate that the #1 sensor daily variations amplitude of earth pressure is 7.22KPa, and the #2 sensor daily variations amplitude of earth pressure is 4.69KPa. In the 479 days, the rangeability of average data is 61.55KPa in sensor #1 and 64.05KPa in sensor #2. Compared with the local precipitation, the earth pressure of tower foundation is seasonal change. According to the history data, the warning threshold value is set as 280KPa.