Advanced Materials Research Vol. 703

Abstract: A new idea is presented which develops a general model predicting the deflection profile of clamped circular diaphragm of Capacitive Micromachined Ultrasonic Transducers (CMUTs) in order to calculate its capacitance. The CMUTs we consider is made of silicon nitride material which is widely used because of its low intrinsic stress. And the general model proposed in this paper is highly accurate in predicting the deformed membranes and exhibits excellent agreement with 3D-FEA results in capacitance deviation less than 1%. These new established deflection functions can be used to implement a much higher accurate design methodology for CMUTs and other MEMS-based capacitive type sensors built with circular diaphragm.

Abstract: Though there are a lot of rules and models for metal material fracture, it makes lots of troubles for engineering application, because of the lacking of reasonable description of fracture principle and change law. This article discusses some basic problems of applying fractal geometry to fracture research, mainly including sectional fractal characteristics and measurement, the relationship of fractal dimension and fracture toughness, and some kinds of metal fractal models. At last, application of fractal theory in metal fracture is stated.

Abstract: Based on the rolling of explosive welded composite sheet the paper described the feature of press working of the explosive welded composite material metals as well as their technologies, structures, properties and applications ,pointing out that combination of explosive welding with the traditional press working process is a new route of significant importance to manufacturing composite material metals with different varieties, shapes, dimensions, properties and applications and thus can achieve greater economical, technical and social benefits.

Abstract: Along with the wide range application of composite material structural parts in the field of aviation, the research of its manufacture technique, especially the research of composite material entirety structure parts with complex outline surface becomes more and more important. This article proceeds the simulation analysis of spring-back transformation caused in proceedings of composite material structure solidifying. It states the necessity of the application of composite material solidifying deformation simulation technology in airplane structures manufacture.

Abstract: Shear banding characterization of Zr_64.13Cu_15.75Ni_10.12Al₁₀ and Zr₆₅Cu₁₅Ni₁₀Al₁₀ BMGs was studied by using Rockwell indention method. The significant difference in plastic deformation ability can be ascribed to different shear banding features. Meanwhile, by using the fusible coating method, thermal effect on shear bands was investigated. We did not see apparently temperature rise in shear bands of these two BMGs through Rockwell indentation.

Abstract: Shear banding characterization of Zr_64.13Cu_15.75Ni_10.12Al₁₀ and Zr₆₅Cu₁₅Ni₁₀Al₁₀ BMGs was studied by using Rockwell indention method. Well-developed shear band pattern can be found for both BMGs after indentation. The significant difference in plastic deformation ability can be ascribed to different shear banding features.

Abstract: Polyvinyl alcohol hydrogel has compatibility and biomechanical properties of human articular cartilage similar and good biological. The implantation in the human body can replace part of articular cartilage, which plays the role of bearing and alleviate the impact force. It has the prospect of clinical application. This paper introduces the research progress of polyvinyl alcohol hydro-gel materials. And compared with the characteristics of articular cartilage, clarify the possibility of repair of articular cartilage defects of the materials.

Abstract: This study aimed at, pre-treatment of sweet potato starch wastewater and acquisition the application conditions of environmental materials though coagulation precipitation. The removal rates of COD and turbidity were investigated by process to find kind and quantity of suitable coagulant, quantity of coagulate aids, pH and setting time. The results showed that poly aluminum ferric chloride (PAFC) was chosen as an optimum coagulant for effective treatment. The optimal coagulation precipitation conditions were determined as follows: pH8, dosage of PAFC 1200mg/l, PAM100mg/l, sedimentation time 30 min. At optimum conditions of coagulation precipitation stages, the removal rate of COD and turbidity reached 25.8% and 67.5%, respectively. Therefore, coagulation process reduced the burden of subsequent wastewater treating.

Abstract: In order to clarify the relationship between spinning conditions and performance parameters of hollow-fiber ultrafiltration (UF) membrane filament, polysulfone (PSF) hollow-fiber UF membrane was prepared, meanwhile, the performance parameters were investigated when the rotation rate of controlled volume pump and the winding speed of UF membrane filament is stationary. It was found that with the water flux of central tube in spinneret increase, the diameter and loading density increase, the thickness decrease, the sectional area and porosity increase, the tensile strength and fracture length increase firstly and then decrease. Comprehensively considering the appearance size and tenacity, the best water flux of central tube in spinneret is 20 ml/min.