Advanced Materials Research Vols. 181-182

Abstract: In this paper, the stability of systems with interval time-varying delay is investigated. The time delay varies in an interval. By employing a new and tighter integral inequality and constructing an appropriate type of Lyapunov functional, the delay-dependent stability criteria are derived. Because neither any model transformation nor free weighting matrices are employed in the theoretical derivation, the developed stability criteria significantly improve and simplify the existing stability conditions.

Abstract: In this paper, fatigue test and numerical simulation are carried out for Q345 weld joint under constant amplitude loading at different R-ratio using the compact tension samples with 3.8mm thickness. The result indicates that fatigue crack growth rates in the base metal is not sensitive to R-ratio, but the fatigue crack growth rates increases in the weld zone with R-ratio increasing. The effect of R-ratio on fatigue crack growth is analyzed based on J-S cycle plasticity model and Jiang’s multiaxial fatigue criterion. The finite element method (FEM) is used for the stress-strain analysis with the implementation of an accurate J-S cyclic plasticity model. With the detailed stresses and strains, fatigue damage assessment is made using a Jiang’s multiaxial fatigue criterion.

Abstract: At present, how to make the computer understand the text message of humanity automatically is a very important issue in computer information technology field. And the problem of word sense disambiguation is a bottleneck of the understanding of natural language. This paper describes the current research situation of word sense disambiguation, introducing its background and application, analyzing various mature approaches, comparing the merits and shortages of those methods, taking a brief introduction of context and international evaluation method of word sense disambiguation and finally making a conclusion of its future and development trend.

Abstract: In this paper, we present the fabrication and characterization of semiconducting carbon nanotube thin-film field-effect transistors (SN-TFTs). High-k dielectric material, hafnium-oxide (HfOX) is used as the gate-oxide of the device. A Thin-film of semi-conducting single walled carbon nanotube (SWCNT) is deposited on the amino-silane modified HfOX surface. Two types of SN-TFTs with interdigitated source and drain contacts are fabricated using 90% and 95% purity of semiconducting SWCNTs (s-SWCNT), have exhibited a p-type behavior with a distinct linear and saturation region of operation. For 20 µm channel length SN-TFT with 95% pure s-SWCNTs has a peak on-off current ratio of 3.5×104 and exhibited a transconductance of 950 µS. The SN-TFT fabricated with HfOX gate oxide has shown a steep sub-threshold slope of 750 mV/decade and threshold voltage of -0.7 V. The SN-TFT of channel length 50 µm has exhibited a maximum mobility of 26.9 cm2/V•s.

Abstract: By tensile tests on GFRP rebar after high temperature, the change regularity and influent factor are analyzed. The results show that: With the temperature increasing, vitrification, carbonization, decomposition at high temperature test section of the GFRP rebar are aggravating , and their mechanical properties are deteriorating. At the same time, the limited tensile strength and ultimate tensile elastic modulus decreased in different degree.

Abstract: Woven fabrics are widely used in industry. In this paper, mechanical behaviors such as tear strength and stab strength of four kinds of woven fabric with different structural parameters were tested on Material Test System (MTS810.23). The tests were all conducted on both warp and weft directions. The failure morphologies of each woven fabric were observed to unveil the corresponding failure mechanisms.

Abstract: In this paper, an asymmetric double circular arc gear which is suitable for large-scale high-pressure gear pumps is introduced. While demonstrated its superiority, the displacement formula of the double circular arc gear pump is derived and the gear parameters are identified. The asymmetric double circular arc gear can meet the needs of large displacement and high pressure. There are advantages such as constant flow, no pulse, and no topping, which make this kind of gear has a bright future.

Abstract: The micro particle brings much harm to some industrials, agriculture and human activities. The mechanical models of micro particle adhesion to the surface and the control, disposal technology have become very important for prevention from particle aggradations. For the sake of deeply comprehending and researching the adhesion mechanism as well as kinematics characteristic, numerical simulation of particle adhesion was made based on compute simulation package, the analysis of results and relevant comparison demonstrate that it can well simulate actual state and the results of simulation show that the capillary force (Fc) is the biggest, by contrast, the electrostatic force (Fes) is the smallest. Further more, it has some valuable instructions and helpful references for control of micro-particle adhesion to surface. At last, the outlook of issue was put forward.

Abstract: This paper analyzes the situation of environmental performance evaluation. It research a range of environmental performance evaluation index. Environmental performance is assessed based on fuzzy mathematics in the paper. The paper describes the theoretical framework of this method, and conduct case studies. Research shows that this method is scientific and objective

Abstract: Annular gap throttle has been used in water hydraulic slide valve which makes the hydraulic full-bridge network of the water hydraulic servo valve different from that of traditional hydraulic servo valve with fixed orifice. Based on liquid resistance theory and hydraulic bridge theory, the load pressure characteristics, pressure sensitivity and static characteristic parameters have been analyzed by the research of hydraulic full-bridge network constituted by annular gap throttle and clearance throttle between flapper and nozzle. The results show that the load pressure characteristics of the hydraulic full-bridge in water hydraulic servo valve keep fine linear relationship with flapper displacement, but the pressure sensitivity decreases in the normal working range of servo valve. However, the pressure sensitivity can achieve a reasonable value by the improvement of hydraulic full-bridge.