Papers by Keyword: Different Materials

Abstract: In this study, the dirt adhered on the tubes of different materials (copper alloy tube, stainless steel pipe, polyethylene-aluminum composite pipe) were studied by the scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, PCR amplification, DGGE electrophoresis analyzers. Experimental results show that the microorganism in dirt on the copper alloy tube is mainly shuttle-type bacteria, and the distribution is dense. Stainless steel pipe’s dirt colony is assembling with long bacilli and cocci, polyethylene-aluminum composite pipe’s dirt is the large bacilli and density cocci. Three kinds of dirt in the pipe contains inorganic crystals with SiO₂ and CaCO_3, and the same type of element, but the content is differences, polyethylene-aluminum composite pipe have greater richness of microbial species, a copper alloy tube’s dirt is of little microorganisms.

Abstract: This experiment wastewater treatment plant set up a device of researching different periods of dirt on the different heat exchanger tubes. The moisture test of dirt were derived from tubes of different materials (copper alloy tube, stainless steel pipe, polyethylene-aluminum composite pipe) is between 92.50% and 96.70%, This shows that the quality of per unit area of dry dirt to describe variation is feasible. The induction period of dirt on the copper alloy is between the 0d and 35d, the growth cycle is longer. In the mature period, the quality of per unit area of dry dirt is 2.031 mg/cm². The induction period of dirt on the stainless steel is between the 0d and 20d, the growth cycle is shorter. In the mature period, the quality of per unit area of dry dirt is 2.627 mg / cm²_. The induction period of dirt on the polyethylene-aluminum composite pipe is between the 0d and 35d, the growth cycle is shorter. In the mature period, the quality of per unit area of dry dirt is 2.863 mg/cm².

Abstract: Acoustic wire plays the role of “bridge” in the signal transmission of acoustic system. The materials used for production of acoustic wire have their own features. They have different advantages to music playback. The functions and materials of acoustic wire reflect that different materials have different music playbacks. Lenitive sound mainly comes from the acoustic copper wire covered by silver outside. The wire covered by silver outside makes neutral sound, and the wire made from copper and silver also makes this kind of sound. The wire made form pure copper basically makes thick sound. Acoustic wire should match with each other properly, which can reproduce music attraction.

Abstract: With the demands of environmental protection and energy conservation, increasing resources and improving environment, TWB (Tailor Weld Blank) as one of green re-manufacturing technologies will be a guiding orientation in industry. In this study, microstructure of welded joint、tensile test、fracture surface、cupping test of the TWB were carried out. Results show that the microstructure of weld is acicular ferrite and plate pearlite. The microstructure of HAZ beside SAPH440 is pearlite and grain ferrite, and the microstructure of HAZ beside DP600 is numbly pearlite and plate ferrite. The results of tensile test show that the shape of the materials after drawing is not easy to be rebounded, plastic deformation of the blanks is excellent, and the SEM of fracture morphology shows that the fracture is ductile and cleavage when the weld line parallels tensile axis. When the weld perpendicular to tensile axial, the deformation of the TWB is uneven, the plastic deformation is poor and the fracture is typical ductile rupture. The research results of the cupping test suggest that the bulging formability of the TWB is worse than that of base materials, and the bigger proportion of the thin blank in the TWB, the better bulging formability of the TWB. Introduction