Key Engineering Materials Vols. 474-476

Abstract: Gearbox vibrations are random cyclostationary signals which are a combination of periodic and random processes due to the machine’s rotation cycle and interaction with the real world. The combinations of such components are best considered as cyclostationary. This paper discusses which second order cyclostationary statistics should be used for fault diagnosis of gear crack. The second order cyclostationary statistical methods are firstly introduced and then applied to fault diagnosis of gear crack. This approach is capable of completely extracting the characteristic fault frequencies related to the defect. Experiment results show that the second order cyclostationary statistics is powerful and effective in feature extracting and fault detecting for gearbox. The experimental result shows that the second order cyclostationary statistics can effectively diagnosis gear localized crack fault.

Abstract: Smart antenna technology can increase channel capacity, improve spectrum efficiency and enlarge cover area by using its spatial diversity ability , which greatly improve system performance . A least mean squares (LMS) is posed for the smart antenna adaptive interference suppression system based on the training sequence. Also , the least mean square (LMS) and least squares (RLS) algorithm are proposed for the design and simulation about interference suppression and compare and analyze the result which can prove the effectiveness about algorithm in TD-SCDMA system .According to the results, the new method with a faster convergence speed, which doesn`t matter with interference environments, is better than LMS.

Abstract: The research reported here examines heat buffering property changes of phase change materials used in textiles. In the study, six types of fabrics with different warmth retention rate catalogued in two groups were used to determine how warmth retention rate of fabric affect heat buffering time of PCM when fabric was wrapped around PCM pouches. It was found that the greater the warmth retention rate of the wrapped fabric, the longer the heat buffering time of the PCM pouch, we also found that the heat buffering time prolonged in direct proportion to the warmth retention rate in different manners for fabrics weaved by fibers that have different heat conductivity. Greater warmth retention rate and smaller fiber conductivity lead to greater increase of the heat buffering time of PCM pouches. The results in this research suggested a possibility about how to control heat buffering time of PCM-containing textiles.

Abstract: This paper implement a nano-structure memristor which based on HP lab memristor.Using electrolyte compose method making Pt nanowires act as nano-structure wires, becoming point contact from liner contact to will enhance quantum effect. Giving key production technology of Pt nanowires,TiO₂, TiO_2-X thin films.

Abstract: Stochastic resonance (SR) enhances the nonlinear system behavior with the assistance of noise. The energy-transfer mechanism makes the weak information revealed in the output spectrum, while the time-waveform is distorted. The factors causing the deviation in the output are presented and the function of the recovery system is proposed. The numerical simulations reveal that the SR recovery method can recover the waveform containing weak information submerged in noise effectively.

Abstract: Shadows widely exist in high-resolution remote sensing images and affect image interpretation in certain degree. Improving the accuracy and efficiency of shadow region detection is always a significant problem in remote sensing image processing field. In this paper, an object-oriented shadow detection approach of remote sensing image is proposed on the basis of analyzing the characteristics of the shadow object. Experimental results indicate the efficiency and validity of our object-oriented approach for shadow detection compared with conventional pixel-level methods.

Abstract: Hexagonal W-type ferrite BaZn_0.6Co_1.4Fe₁₆O₂₇ was prepared by the sol-gel method. The formation, microstructure, element composition and phases were analyzed by TG-DTA, SEM, EDS and XRD. The electromagnetic parameters and microwave absorption capability were measured by the microwave vector network analyzer. The results showed that the reflection loss of the ferrite BaZn_0.6Co_1.4Fe₁₆O₂₇ in the spectrum of 8-18GHz came up to -10dB and came up to -20dB in the spectrum of 9.5-16.4GHz.

Abstract: In order to improve the pitch perception of cochlear implant (CI) users speaking tonal language, it has been suggested to frequency-modulate the electric stimulus rate by the spectral information of the tonal language. A piecewise CI rate modulation strategy has been recently proposed, which not only encoded the spectral information but also took account of the psychological perception feature for the stimulus rate variation by CI users. This paper further examines its performance to convey Mandarin tonal information by a neural-network-based simulation. The experimental results shown that the correct rates to identify the four Mandarin tones of 80 Mandarin monosyllabic words were 95%, 95%, 100% and 100%, respectively, indicating that the piecewise rate modulation strategy might efficiently convey Mandarin tonal information. Therefore, the piecewise rate modulation strategy could help to design novel CI electric stimulator and enhance the speech perception ability of CI users speaking tonal language, such as Mandarin.

Abstract: This experiment isolated a series of endophytic bacteria strains form the healthy Camellia leaves. And the strain L32 had significant inhibitory effect to Camellia soft rot disease pathogen. The strain colonies in PDA medium was circular, surface drape, colony propagation rate was faster, ivory; in the early stage of growth the colony edge was neat; and later stage of growth it became corrugated, the centre of colony was uplift and opaque. Carry on the physiological and biochemical experiments and molecular identification, it was judged that the strain L32 had high relationship with the Bacillus subtilis.

Abstract: In this study, biologically treated leachate was treated using PAC and PAC + PAM, respectively, to study removal efficiency of COD, SS and color as a function of such influencing factors as pH, dosage of PAC and/or PAM. It was found that optimal dosage and pH are 800 mg/L and 6 for PAC. The optimal condition when using PAM + PAC for removal of COD was 10-minute reaction, pH of 5, PAC dosage of 800 mg/L, PAM dosage of 3 mg/L. Effluent quality after coagulation at the optimal conditions met requirements of the tertiary standard described in “Integrated wastewater discharge standard”. Coagulation using PAM + PAC at the optimal condition was recommended for advanced treatment of refractory leachate after biochemical treatment.