Advanced Materials Research Vols. 482-484

Abstract: This paper proposes a gross error judgment criterion and diagnoses the transformer fault by integrating the gross error judgment criterion and the characteristic gas ratio method. In this way it is possible to judge whether the transformer is in face of an incipient fault by examining the gross errors of the measured values of the fault characteristic gases, at the same time the fault probability could be calculated according to the remarkable level. And then in combination with the characteristic gas ratio method, the fault category and fault cause of the transformer could be figured out. The method has been validated by an actual example of fault diagnosis.

Abstract: Product family is widely used in the modern manufacture enterprise to alleviate the cost pressure taken from differential customer needs. The quality of product family design determines the ability of a company to gain competitive advantage. The presented work for product family design focus on engineering design field, and the influence from the enterprise strategy is ignored. Using value chain analysis as a tool, the concept of product family design chain could be formed by taking the strategic elements into product family development process. Design chain can be examined from three domains, namely strategy analysis, preliminary design and scheme optimization. The competition advantage of enterprise comes from the excellence in the each link of design chain. Through a series of concurrent engineering, product platform design bring the cost advantage, and the customization design realized the ascension of customer satisfaction.

Abstract: The finite element model of the liner rolling guide of the CNC machine tool is established. Then the natural frequencies and the corresponding vibration modes of the liner rolling guide (LRG) are obtained by analyzing the finite element model (FEM) of the linear rolling guide in two different boundary conditions. By comparing the modal characters of the two states it is proved that the movable joint and bolted interfaces of the rail have certain effects on the dynamic performance of linear rolling guide. Besides, the liner rolling guide also have been tested dynamically, obtaining the modal parameters of the rail guide; finally, the validity of finite element model and the effect of boundary conditions on the interface of the linear rolling guide are verified by comparing the finite element analysis of frequency and experimental analysis of frequency

Abstract: The paper presents a laser irradiation method for rapidly fabricating Fe-based nanocrystalline alloys using Yb-doped fiber laser with a wavelength of 1070nm by overlapping irradiation of the heated areas. The samples are annular cores rolled with 20μm-thick and 3.2mm-wide belts of amorphous alloy Fe_73.5Cu₁Nb3Si_13.5B₉ , which have internal diameter of 14 mm and external diameter of 20 mm. Every side of the samples is irradiated for 15 min by fiber laser. X-ray diffraction and transmission electron microscopy (TEM) are used for microstructure analysis and observation. The samples irradiated by a defocus beam with a diameter of 7.1mm through a lens have better soft magnetic properties than directly by an original collimating beam with a diameter of 6.7mm. The dimension of homogeneous ultrafine grains is about 10nm with a bcc α-Fe (Si), which is the foundation of the excellent soft magnetic property. Uniform laser irradiation and the appropriate laser power are necessary for optimum microstructure and soft magnetic properties.

Abstract: To remanufacture hard chromium-plated workpiece, nano-Al₂O₃/Ni-Co composite coatings and Ni-Co alloy coatings are developed using electric brush plating technology. Scanning electron microscopy (SEM) and transmission electron microscope (TEM) are used to analyze the surface morphology, phase structure and wear properties of coatings. The surface morphology of nano-composite coating is more compact. The nano-particles are well-distributed in the coating and bounded tightly with the substrate. The hardness of composite coating is HV1027, increased approximately 38% compared with Ni-Co alloy coating, overtaking the hard chrome plating. The results of sliding wear test shows that the nano-composite coating reduces friction coefficient, increases wear resistance significantly and exceeds the chromium plating.

Abstract: The intelligent diagnosis based on medical services is proposed in this paper. Medical knowledge on the relation between results of chemical examination and diseases is learned by Artificial Intelligent(AI), and medical knowledge is encapsulated as Web service, finally intelligent diagnosis platform based on medical services is established. Besides, the way on intelligent diagnosis based on medical services is proposed in this paper, and intelligent diagnosis can serve the patients in this way, which will improve the efficiency and accuracy for diagnosis.

Abstract: In this paper, the low-temperature (less than or equal to 400 °C) silicon wafer direct bonding technology using wet chemical surface treatment is proposed. For bonded pairs of silicon-oxide-covered wafers, the optimum process condition is established with respect to the experimental results of two different wet chemical processing methods. The bonding quality is evaluated through infrared transmission test and tensile test. Experimental results indicate that the bonding strength of the additional 29% NH3•H2O treated samples is about 7.2 MPa, while it is no more than 3.1 MPa for the only piranha (H2SO4/H2O2) solution and RCA1 (NH3•H2O/H2O2/H2O) solution cleaned samples. Effect of the pulling speed on tensile test is also investigated. The results show that the pulling speed effect should be considered during the tensile test.

Abstract: With more and more Chinese construction enterpries listed in the most competitive 225 international contractors, there are still many problems challenging the International Engineering Projects of Chinese construction contractors which can be verified by the recent light rail project carried out by the Chinese railroad construction company in Saudi Arabia. Inspired by the failure experience, the paper investigates deeply the major problems challenging the Chinese international contractors and finally some practical and urgent solutions are proposed.

Abstract: In the paper, we establish an evaluation system in the study of four aspects such as people, regulation, equipment and technology management, field management and engineering construction. We present an entropy weight multi-level fuzzy comprehensive evaluation model in power plant security on the basis of reliability identification. Firstly, it identifies the reliability of power plant security evaluation system. Secondly, it can meet the condition that the system is reliable. Then it obtains the indicator weight of all levels in the evaluation system by the entropy weight method. Finally, it carries out a comprehensive evaluation in power plant security by the multi-level fuzzy evaluation method.

Abstract: Mode shape decomposition response spectrum method is used to determine the earthquake effect of the multi-mass elastic system by means of combination of the response spectrum of a single-mass elastic system. Although it is a simple method, the calculation process is too complicated. In this paper, a general program for seismic response calculation is designed using ANSYS Parametric Design Language (APDL). First, the computational model is established. Then, the modal analysis of the structure is done to extract natural frequencies and mode shapes. The third step is to input the response spectrum so as to decompose mode shapes, and the corresponding mode shape having the maximum seismic response is obtained. After that, the method of SRSS or CQC is used to combine modal shape. The general program has been applied to calculate a one-bay two-story reinforced concrete frame structure. The numerical results are good agreement with the classic structural mechanics method.