Papers by Keyword: Probe

Abstract: In this study, a long stroke atomic force microscope (LS-AFM) has been developed for the measurement of the micro-optics which have micrometric amplitude surface structures. An electrochemically polished tungsten wire is used as the AFM probe tip. Since the effective length of the tungsten probe is more than 100 μm, the probe tip can access valley part without the interference between the steep slope and the sidewall of the probe tip. By using the long stroke PZT Z scanner whose long stroke of 70 μm and a resolution of 1 nm, micrometric amplitude of the optical elements can be measured. A linear encoder is employed to measure the displacement of Z scanner in Z direction. A well-detected result of a prism sheet film profile has been obtained by the LS-AFM and its tapping mode.

Abstract: A testing circuit of probe is designed to research the electrical properties of the probe under different loading frequencies. Sinusoidal signals of different frequencies are produced by Tektronix AFG3102 signal generator, and DSOX2022A Oscilloscope is used to measure the probe voltage,constant resistance voltage and the source voltage, so the phase between the probe voltage and constant resistance voltage can be calculated. Assumed the constant resistance is a pure resistance. Since the circuit is connected in series, so the phase between the probe voltage and the probe current can be calculated. The result reveals that the probe shows resistive when the phase between the probe voltage and the probe current is 0 ° within 200 KHz frequency. Beyond 200 KHz the phase between the probe voltage and the probe current increases to 60 ° and then declines to a steady value 40°, which shows that the probe is inductive.

Abstract: Atomic Force Microscope (AFM) works by the force between the probe tip and specimen surface. The nanocontact force between the probe tip and specimen surface has an important influence on the detection surface. Base on the analysis of the working principle of the AFM and nanocontact force calculation model, according to Hamaker assumptions, using continuum method established the theoretical contact force model of the AFM tip. the contact force calculation methods of contact pressure in process has been obtained. The variation of the force between the probe tip and specimen surface has been found by calculation model and programming calculation of Matlab. Provide the basis for improving the accuracy of an atomic force microscope surface inspection and error analysis

Abstract: The paper analyzes the forms of different probe pole distribution automatic detection equipment inspection speed setting principle; Combined the common failure modes of several kinds of probe or channel, in order to ensure the detection achieve 100% scanning coverage and discusses the detection speed setting problem.

Abstract: The erosion and wear mechanism for drilling equipment is studied in this paper, which is for the problem of unstable performance of drilling system and short lifetime caused by the erosion of drilling equipment by drilling fluid. The flow field, surface pressure of the erosion prone parts and drilling fluid flow rate are calculated by the finite element method. The results demonstrate the parts eroded seriously by drilling fluid appear in where the curvature of the curve of the wall changes suddenly and where the rate of change in the stress field is greater, which provide a theoretical basis on design, optimize, repair of drilling equipment.

Abstract: A new coumarin derivative L was synthesized and characterized by ¹H NMR, ¹³C NMR, IR and mass spectrum. UV-Vis and fluorescence emission spectra of L without or with different anions (NO₂, F, Cl, HSO₃, HSO₄, AcO or NO₃) or metal ions were measured, which showed while addition of anions or metal ions Mg²⁺, Zn²⁺, Ca²⁺, Cu²⁺, Ni²⁺, Co²⁺, Fe³⁺ or Al³⁺ led to decrease in intensity of the maximum emission peak at about 480 nm, addition of Hg²⁺ ions caused increase in intensity of the maximum emission peak, suggesting that L may act as a fluorescent probe for detection of Hg²⁺ ions.

Abstract: Withdrawal resistances of wood have been applied for in situ assessment of wood in existing timber structures. The author had proposed method to estimate shear strengths of wood from measured withdrawal resistances of probes which are screwed into wood. In order to verify the accuracy of these estimated shear strengths by proposed methods, withdrawal resistance measurements and shear loading tests were conducted for wood. Single withdrawal resistance measurement was applied for wood specimens, and estimated shear strengths from withdrawal measurements were compared to the measured shear strengths by shear loading tests of wood. Correlation between the estimated shear strengths and measured shear strengths of specimens was reasonably good (R2=0.73). Multiple coaxial withdrawal resistance measurement which can provide distribution of shear strengths in cross-section of wood was also proposed. The average of estimated shear strengths by single withdrawal resistances was 7 percent less than that of measured shear strengths. The average of estimated shear strength by multiple coaxial withdrawal resistances was 3 percent greater than that of measured shear strengths. The single withdrawal measurements and multiple coaxial withdrawal resistances are available to estimate shear strengths of wood and shear strength distribution in the cross-section of wood. Estimated shear strengths obtained from these methods will be valuable for strength based in situ assessment of wood.

Abstract: A novel technique using solar power to irrigation was proposed. In order to obtain better sensitivity, small dense probe, single strand copper probe, bifilar winding type probe and rectangular cross section type probe were designed. Through the experiments, the electrical resistance of four kinds of probe structure was determined. Test results show that conductivity of small dense probe is the worst, conductivity of single strand copper probe is better. Graphite content has great influence to probe resistance value, resistance and graphite content in the relationship is not linear.

Abstract: It is studied that a great proportion of traffic problems lies in vehicles’ steering system, and the maximum steering angle decides their steering capability and their minimum turning radius. The measuring principle of rapid measuring system, and the automatic tracking principle of measurement system have been analyzed in the paper. Also, the infrared tracking, the measuring plate positioning, the calculation of minimum turning radius, and the processing method of the test results have been described in detail. It is proved that the automatic automobile steering angle detecting system has reached the general requirements both in detection resolution and the measuring accuracy.

Abstract: This paper tries to design a stripline-type inductor with high sensitivity that is used for micro-fluid in downhole nuclear magnetic resonance (NMR) detection. It discusses the design theory for the probe, and does analysis and simulation to guide the optimal geometric parameters. Radiofrequency B₁ field homogeneity is evaluated. Finally, the prototype is made.