Surface plasmon resonance (SPR) and common-path phase-shift interferometry (PSI) techniques are integrated in a biosensing imaging system for measuring the two-dimensional spatial phase variation caused by biomolecular interactions on a sensing chip without the need for additional labeling. The common-path PSI technique has the advantage of long-term stability, even when it is subjected to external disturbances. Hence the system meets the requirements of the real-time kinetic studies involved in biomolecular interaction analysis. The proposed SPR-PSI imaging system demonstrates a detection limit of a 2 x 10(-7) refractive-index change, a long-term phase stability of 2.5 x 10(-4) pi rms for 4 h, and a spatial phase resolution of 10(-3) pi with a lateral resolution of 100 microm.

It has been well known that the ionospheric electron density N e is greater in the summer nighttime than daytime around the Weddell Sea region, which is named Weddell Sea Anomaly (WSA). This paper for the first time reports unusual increases (decreases) of the daytime (nighttime) electron temperature T e at about 830 km altitude over the WSA latitudes probed by Tatiana-2 during December 2009 to January 2010. Concurrent measurements at 660-830 km altitude observed by Tatiana-2, Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER), and Formosa Satellite 3/Constellation Observing System for Meteorology, Ionosphere and Climate (F3/C) reveal the anticorrelation between T e and N e along the WSA latitudes in the daytime and nighttime. Based on F3/C N e along the WSA latitudes observed at various local times, the associated T e values are computed. The Tatiana-2 and DEMETER observations as well as the computed results show that T e yield the maximum values over the WSA region during daytime and over the Indian and Atlantic Ocean area during nighttime. The maxima or minima in F3/C N e and the computed T e reveal eastward phase shifts.

The magneto-resistive magnetometer (MRM) of the Block of Central University (BCU) payload onboard the Tatiana-2 satellite is made of anisotropic magneto-resistive (AMR) sensor chips, which have appealing features of small size (10 × 15 × 7 mm 3 ), light weight (2 grams) and low power consumption (100 mW). The small MRM is packaged together with other instrument/subsystems of the BCU into a 1.6 kg payload box for convenient installation. In this report, we present the design, calibration, and flight data analysis of the MRM. In particular, the detailed methods of pre-flight calibrations are described. The calibrated data revealed typical patterns of the global geo-magnetic field structure and of field-aligned current (FAC) distribution in the high latitude ionosphere, though the MRM of BCU only has a resolution of 24 nT and a sampling rate of 2.22 Hz. Moreover, the current density derived from our magnetic field measurements are about 2 and 3 μA m -2 , respectively, for downward and upward FAC, which are comparable to those typically observed at auroral latitudes during a quiet geomagnetic condition.

Surface plasmon resonance (SPR) sensing and an enhanced data analysis technique are used to obtain precise predictions of the dielectric constant and thickness of a nanolayer. In the proposed approach, a modified analytical method is used to obtain initial estimates of the dielectric constants and thicknesses of the metal film and a nanolayer on the sensing surface of a SPR sensor. A multiexperiment data analysis approach based on a two-solvent SPR method is then employed to improve the initial estimates by suppressing the noise in the measurement data. The proposed two-stage approach is employed to determine the dielectric constant and thickness of a molecular imprinting polymer nanolayer. It is found that the results are in good agreement with those obtained with an ellipsometer and a high-resolution scanning electron microscope.

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