Three different nanosensors with core-shell structures were fabricated by molecular self-assembly and evaporation techniques. Such closely packed nanoparticles exhibit fine optical properties which are useful for biochemical sensing. The refractive index sensitivity (RIS) of nanosensors was detected by varying the refractive index of the surrounding medium and the decay length of nanosensors was investigated using a layer-by-layer polyelectrolyte multilayer assembly. The results showed that the thickness of the Au shell plays an important role in determining the RIS and the decay length. A system based on localized surface plasmon resonances (LSPR) sensing was constructed in our study. The core-shell nanosensors can detect 10 ng/mL atrazine solutions and are suitable for pesticide residue detection.
Inductively coupled power transfer (ICPT) systems, which are superior to batteries due to their real-time power supplycapacity have been used in mooring buoys for the purpose of long-term measurements. A multiple-receiver ICPT system for mooring buoys, which contains a mooring cable for transmitting power, is proposed in this paper to obtain the corresponding profile parameters. Series compensation is applied to all three sections, including the transmitter, the mooring cable and multiple receivers. The voltage of an underwater system with arbitrary load can be stabilized. On that basis, high efficiency can be obtained. By adopting Wolfram Mathematica a detailed analysis of both double-receiver and multiple-receiver ICPT systems for mooring buoys is presented. Finally, a prototype ICPT system with three receivers mounted on a 30 m mooring cable was built to verify the theoretical analysis. Experimental results show that the power transfer efficiency exceeds 45%. Both theoretical analysis and experiments indicate that this system is appropriate for measuring ocean profile parameters.
The magnetohydrodynamics angular rate sensor (MHD ARS) has received much attention for its ultra-low noise in ultra-broad bandwidth and its impact resistance in harsh environments; however, its poor performance at low frequency hinders its work in long time duration. The paper presents a modified MHD ARS combining Coriolis with MHD effect to extend the measurement scope throughout the whole bandwidth, in which an appropriate radial flow velocity should be provided to satisfy simplified model of the modified MHD ARS. A method that can generate radial velocity by an MHD pump in MHD ARS is proposed. A device is designed to study the radial flow velocity generated by the MHD pump. The influence of structure and physical parameters are studied by numerical simulation and experiment of the device. The analytic expression of the velocity generated by the energized current drawn from simulation and experiment are consistent, which demonstrates the effectiveness of the method generating radial velocity. The study can be applied to generate and control radial velocity in modified MHD ARS, which is essential for the two effects combination throughout the whole bandwidth.