Advanced Materials Research Vols. 181-182

Abstract: Latent Semantic Indexing(LSI) is an effective feature extraction method which can capture the underlying latent semantic structure between words in documents. However, it is probably not the most appropriate for text categorization to use the method to select feature subspace, since the method orders extracted features according to their variance,not the classification power. We proposed a method based on support vector machine to extract features and select a Latent Semantic Indexing that be suited for classification. Experimental results indicate that the method improves classification performance with more compact representation.

Abstract: Influence of coupling agents on microstructure and mechanical properties of short glass fiber reinforced PA66 composites(SGF/PA66) were investigated by using twin screws extruder and injection machine in this paper. When coupling agents (A1100 or A1100+A+B) were added, short glass fiber was distributed in the PA66 matrix more homogeneously; at the same time, the microstructure and properties of GF/PA66 were improved too. Modified effect of multiple coupling agent (A1100+A+B) is better than that of only A1100 and the desired content of A1100 is about 1.5~2.0wt%. When glass fiber content was less than the critical value (35~40%), mechanical properties of PA composites increase with fiber content increasing, but it begin to decrease when content was excess that value. At last, Failure mechanism of GF/PA66 (treated by A1100 or A1100+A+B) was obtained: adhesion of interface between glass fiber and PA66 matrix, friction after the adhesion, glass fiber pullouted and matrix failure.

Abstract: Nuclear fusion is a promising source of environmental friendly energy for the future, and the ultra-fine grained Tungsten (W) is a hopeful candidate material to be used as plasma-facing materials (PFMs), which are the key materials in the International Thermonuclear Experimental Reactor (ITER), for its many useful advantages. While, due to its high melting point and high sintering temperature needed, the ultra-fine grain sized tungsten is not easy to be fabricated. In this paper, the method of explosive consolidation of powders as well as its mechanism and improvements are discussed, and finally the possibility of using this method to preparing of ultra-fine grained W plasma facing material are also introduced.

Abstract: The numerical simulation of flow field and pressure field in the micro-region with different power ultrasonic were performed by FLUENT6.3 simulation software. Ultrasonic power on mass transfer effect was analyzed through the simulation results combined with surface morphology of micro casting. The results illustrated that micro electroforming assisted with appropriate power ultrasonic can significantly enhance mass transfer process and improve surface morphology of micro casting. And it was confirmed that Fluent was reliable in simulating the effect of ultrasonic on mass transfer and helpful to optimize and design deposition experiments with ultrasonic.

Abstract: Environment protection and sustainable development are recognized to be more and more important in the construction of road engineering. For this reason, a new kind of mixture-warm mix asphalt (WMA) is put forward，whose mix temperature lies between hot mix asphalt (HMA) and cold mix asphalt (CMA). Moreover, WMA may be compact in lower temperature without sacrificing performance. The review is focused on research and application of warm mix asphalt in China. And a few problems in application of warm mix asphalt are stated.

Abstract: In this paper, the differential equations of box beams are established based on the principle of minimum potential energy and the variational method. The elastic stiffness matrix and geometric stiffness matrix considering shear lag and compression-flexure effects are induced in this paper. And a finite element program is developed. Then the influence of compression-flexure effects to shear lag effect of box beam is analyzed.

Abstract: Sulfur is the main element which caused Nickel-based alloy embrittlement. In this study, the sulfur in Hastelloy X superalloy was determinated with Auger Electron Spectroscopy (AES) for samples quenched from 1180 °C and aged at 500 °C for different time. Experiments results confirmed the non-equilibrium segregation characteristics of sulfur. The results showed that a segregation peak of sulfur is at about 20 min during ageing. This peak was satisfactorily elucidated by the theory of non-equilibrium grain-boundary segregation. By theoretical calculation, the critical time constant of impurities sulfur atom in the Hastelloy X δs= 357. At the same time, the result provides a theoretical basis for sulfur segregation mechanism.

Abstract: Task running in Grids may require multiple types of resources simultaneously. Proposing and designing a resource discovery scheme based on Economic Agent. Base on the economic model and the technique in agent of grouping nodes sharing similar files to improve efficiency, this thesis suggests a resource discovery scheme based on economic agent, which is called EAGRD. Theoretical models on resource discovery are provided, under which EAGRD is compared with existing schemes theoretically. By controlling propagation of message into related communities, EAGRD improves time and network efficiency at the cost of topological maintenance overhead.

Abstract: The evolution operator method is applied to studying the time-dependent and spin-related electron transport through a quantum dot coupled to two magnetic-metal leads. When the microwave field is applied on quantum dot there are additional peaks of PAT current besides the main peak of resonant tunneling current, and the energy distance between peaks relate to the frequency of microwave fields. Furthermore, Furthermore, owe to the magnetism of lead, the spin-up and spin-down current is different in the parallel magnetization configuration while the same in the antiparallel magnetization configuration.

Abstract: In recent years, with the rapid development of higher education in China, the scale of every university unceasingly expands and many universities are building new campus or are intend to construct new campus. The construction of new campus needs large-scale capital, although various universities try every means to raise the funds, the main source of construction capital is bank loans. In this paper, we, at first, put forward the background and significance studying the factors affecting the loan scale of the construction of new university campus, then, we screened the factors affecting the loan scale of university and made use of the data of these factors for statistical analysis. Finally, we summarized the results of statistical analysis.