Applied Mechanics and Materials Vol. 142

Abstract: In order to simplify the pretreatment process in detection of pesticide residues in vegetables and improve the extraction recovery, an ultrahigh pressure technique was adopted in pretreatment experiments on organophosphorus pesticide residues in cabbage, and on the basis of single-factor test, orthogonal pre-conditions were optimized. The results showed that: The optimum process conditions for ultrahigh pressure extraction of dimethoate in cabbage at room temperature are: pressure of 400MPa, extraction solvent volume of 60ml, the holding time of 4min, recovery rate up to 91.3%, compared with the conventional homogenization method, extraction efficiency improved significantly.

Abstract: In order to simplify the process of detecting pesticide residues in vegetables, reducing detection time to find a more efficient detection method, ultrahigh pressure processing technique was applied to NIR detection experiments on dimethoate residues in Chinese cabbage, the spectral data was pre-processed and optimized and a spectrum model was established. The results show that: ultrahigh-pressure extraction process did not affect the absorption of near infrared spectroscopy of extraction reagent acetone. A PLS model on near-infrared spectroscopy of samples within the range of 4100-11000cm^-1 was established, obtaining a correlation coefficient R of 87.14%, Rank of 9 and RMSECV of 0.139. Residual concentration of 10^-4-10^-5 has a small relative error, the prediction is better. Further processing and selection of samples will expand the range of predicted concentration.

Abstract: Photo-curable resin’s solidification under beam exposure in integral stereolithography (SL) is a dynamic process. Firstly, the up-part in photo-curable resin solidifies after absorbing enough energy; and then with the beam exposure, after the beam penetrates the solidified resin, the liquid resin under solidified resin have the opportunity to be cured. But the model which describes the solidification characteristics for photo-curable resin in SL process does not reflect the dynamic characteristics, and obvious predicting error will be introduced. In this paper, a solidification characteristics model of the photo-curable resin UV-2230, which describes the resin’s dynamic characteristics in solidifying process, is established with least square method in experiments. By using the model, critical exposure of the resin, penetration depth of the liquid resin and penetration depth of the solid resin are obtained. The research provides a base for improving the building accuracy for integral SL system.

Abstract: This study presents the warpage analysis for products through the combination of the genetic algorithm (GA) method and finite element method (FEM) in multi-cavity injection molding parts; it simulated and analyzed the warpage through controlling the conditions of various parameters in primary processes – filling, packing, and cooling. After 50 iterations of calculations. These results demonstrate that the maximum warpage of the products was 0.5052 mm for multi-cavity injection molding parts. In comparison with the orthogonal array, the maximum warpage could be reduced by approximately 7.24%. It is shown that the GA method can obtain the optimum process conditions for warpage deformation in multi-cavity injection molding parts.

Abstract: Using carbon nanotubes as cold cathode material, the panel fabrication for the diode field emission display (FED) with symmetrical electrode stripe was studied. The indium tin oxide (ITO) film was used as conduction electrode on the substrate plate surface, and the precise photolithography method was adopted as the high effective fabrication process. For the both cathode and anode plate, the whole ITO film would be etched in the bar form, and the divided bar ITO stripe would be arranged symmetrically. On the cathode plate surface, the printed silver slurry was used to form the cathode extension lines and the cathode insulation layer was formed with the sintered insulation slurry. Whether for the cathode ITO electrodes or for the anode ITO electrodes, the length of bar ITO electrode become small, which would be beneficial for reducing the panel working-voltage. The FED panel was sealed and measured, which possessed good field emission characteristics.

Abstract: With simple screen-printing method, the short-stripe insulation wall was fabricated. In the manufacture course, the insulation slurry was printed on the cathode glass plate surface. After the sintering process, the short-stripe insulation wall with better insulation performance would be formed. For the field emission display panel, the short-stripe insulation wall mainly possessed good separation action and support function, which not only was profitable for the subsequent panel exhausting, but also its simple fabrication process was also confirmed. Using carbon nanotube as field emitters, the field emission display panel was developed, which showed good field emission properties, such as good uniformity and image display function.

Abstract: In order to sign correctly, quickly and clearly, an automation stamping machine is designed and manufactured. This paper mainly introduces principle of the system, including whole architecture, motion control system, mechanical system and software realization method. The running result shows that the system is reliable and easy to be operated and that it realizes the intended functions of stamping automatically.

Abstract: Since the reform and opening, China's economy has achieved remarkable results, for various industries have developed rapidly. After 2 decades, 1950s and 1990s, China's vacuum industry also has get dramatic development and vacuum equipments have been widely applied in the electronics industry, especially in the semiconductor and integrated circuit production. This paper described the detection process and method of high vacuum magnetron sputtering equipment, utilized the one-by-one elimination to determine the key emphasis in work and succeeded in finding the cause of the substantial decline in the vacuum degree, then elaborated the results and effectiveness of detection, and finally made a conclusion. This paper has a referential significance on the maintenance of the same kind equipment.

Abstract: The Working devices act as the direct-effect device of the emergency dealing vehicle in an emergency disaster relief, which includes the manipulator. We can use Pro/E to build parts models and assemble them into a whole. We should make sure no movement interference before we import them into ANSYS. In ANSYS, we need to make stress analysis of manipulator when the fire robot grabs objects, carry objects and uninstall objects, which will ensure the size of each part perfect. Afterwards, we do modal analysis to avoid resonance.

Abstract: Based on analyzing the structure and dynamic characteristics of this system, a dynamical mathematical model is established. To overcome the problems when using fuzzy controller or PID controller respectively and increase precision, a P-fuzzy-PID mode controller and a fuzzy PID controller is designed to control the system. The module of simulink which is a part of MATLAB is used to construct a monolithic mould. The fuzzy logic toolbox is used to construct a fuzzy mould. The results of simulation show that the performance of control becomes better by using this design.