Advanced Materials Research Vols. 945-949

Abstract: We herein constructed a sensor that converts T4 DNA ligase-induced conformational transformation of the probe DNA to electrochemical response based on host-guest recognition and nanoparticle label. In the sensor, the hairpin dsDNA terminal-labeled with 4-((4-(dimethylamino)phenyl)azo)benzoic acid (dabcyl) and thiol group was immobilized on Au electrode surface as the probe by Au-S bond, and the CdS nanoparticles surface-modified with β-cyclodextrins (CdS-CD) were employed as electrochemical signal provider and host-guest recognition element. After T4 DNA ligase repairing single-strand breaks in duplex DNA, the dsDNA probe underwent a significant conformational change, which forced dabcyl away from the electrode. As a result, formerly shielded dabcyl became accessible to host-guest recognition between β-cyclodextrin and dabcyl, thus the target repairing event could be sensitively transduced to electrochemical signal provided by CdS-CD.

Abstract: Due to the requirements of on-line detection of grinding force in the grinding process, this paper utilizes the structural characteristics of ultra-precision grinder with double-spindle and single-workstation, and then presents a grinding dynamometer based on piezoelectric effect of quartz crystals. Besides, the grinder dynamometer can measure grinding force in three directions, and the static properties of dynamometer are experimentally tested in a special experiment table. Moreover, the on-line static calibration and the actual grinding experiment of dynamometer installed in the silicon wafer grinder are performed. The results indicate that the grinding dynamometer has satisfactory static properties, that is, the linearity and repeatability are less than 1%, and the cross-talks are also less than 5%. As a result, each indicator has full reached the operating requirements in using of large diameter silicon wafer grinding force measuring.

Abstract: To solve the problem of moving defect localization for wheel-bearings, a novel algorithm based on particle filter and multiple signal classification (MUSIC) is proposed in this paper. It introduces two-dimensional circular sensor array to measure acoustic signals of defective bearings. By through of MUSIC, the direction-of-arrivals (DOAs) of defective signal are firstly estimated. After the motion trajectory was calculated by particle filter and DOAs, the defect was located by reference sound source. The experimental results show that the radius and phase errors of proposed method are less than 2mm and 5 degrees.

Abstract: This paper presents the method for quality measurement method about collapsible fuel tank, and mathematical model about the quality of the fluid inside collapsible fuel tank is set up. Comparing the calculate results and principle experimental obtained results, the method of quality measurement is validated. The method is characterized in simple and high measurement precision, which can be extended to apply in measuring the quality of liquid of large-scale irregularly shaped or collapsible fuel tank.

Abstract: Coplanar capacitive sensors have been widely applied in many fields with its characterstics of non-invasion, lowcost and fast response. A complex structure of coplanar capacitive sensor is designed to be used for the film thickness measurement. Firstly, three types of coplanar capacitive sensors with different shapes are designed, and according to the experimental reuslts, the parameters affecting the sensor signal strength and sensitivities are discussed, the electric field distributions of sensors are simulated by COMSOL.Then the fringe capacitance of a series of spiral-type sensors are measured and analyzed. The experimental results indicate the rational geometrical parameter design about the coplanar capacitive sensor can improve the sensor performance obviously.

Abstract: Oxygen indicator can monitor the quality and safety of the food that transport from producers to consumers by perceiving the oxygen concentration in packaging, and then inform the consumer about the product’s safety, shelf life and availability by sensing the visually physical change, which will widely used for modified atmosphere packaging in food packaging.

Abstract: The detection of weak transient signal buried in non-Gaussian noise is investigated. Non-Gaussian noise is modeled by Gaussian mixture distribution. 3-level quantizer is used as a nondynamic stochastic resonance method to enhance SNR of weak signal. NL-length samples of signal are arranged into a matrix. Every column of the matrix is calculated into M-level decomposition. Based on the squared value of the detail and approximation coefficients, a novel Power-Law detector in wavelet domain is established. Numerical experiments and comparison show that, on the same SNR and false alarm rate, proposed method could provide higher detection probability.

Abstract: Based on the bucket teeth load-time courses calculation model under bucket digging condition, the stresses on the hydraulic cylinder piston rods of boom and bucket and the real-time length of bucket hydraulic cylinder were set as measured variables, and a measuring method of the bucket teeth load-time courses was developed which had the advantages of less measuring points, simplified measurement process and low cost. The bucket teeth load-time courses were calculated by inputting the measuring data into the self-developed Constructing Hydraulic Excavators Load Spectrum software, and its characteristics of each digging step in one excavation cycle at digging macadam were analyzed. Then, using rain-flow counting module in FE-SAFE software, the statistical graphs of bucket teeth load-time courses were acquired which could provide the basis for hydraulic excavator reliability design and fatigue life prediction.

Abstract: In this paper, iron tower component is taken as measuring object, online automatic detection is aimed to achieve, and the system frame is constructed to carry out electro-optic automatic detection of the iron tower component, then designing of large size examination machine will be accomplished, which will set up the foundation of theory and the technology for large size examination machine development.

Abstract: Active power filter (APF) is a new power electronic device used for reactive power compensation and dynamic harmonic suppression. Its performance depends on the highly precise detection of harmonic and reactive current. In view of the low pass filters defection in traditional i_p-i_q method, this paper proposes a wavelet filter based on wavelet analysis. This algorithm could attain higher detection precision with lower cost. The simulate results illustrate the efficiency and accuracy of it.