White light cavities with broadband resonance are usually filled with negative dispersion medium, which inevitably leads to gain. In this article, pure passive white light cavities are designed, in which negative dispersion medium is no longer necessary. Theoretically, if the reflection phase of the cavity wall can exhibit a negative dispersion slope, then it can also satisfy white light cavities conditions without medium. In practice, the negative dispersion property of the cavity wall can be realized by two metal coatings with different reflection coefficients. Therefore, our white light cavities are composite cavities, in which the main cavity provides resonance while the auxiliary cavity forms the cavity wall, providing negative dispersion reflection phase. Further, atomic gas can be employed to improve the performance of the white light cavities. Atomic gas exploits effects such as Electromagnetic Induced Transparency (EIT), enabling the white light cavities to be controlled by coherent driving field. With the passive characters, our design can be realized and implemented much more easily.
Paint coated corrosion detection and evaluation is a big challenge for steel performance and structure health. Eddy current pulsed thermography (ECPT) technique is investigated because it can reflect the corrosion physical properties through paint coating by the infrared signal. This paper proposes skewness method, which presents the feature of temperature curve’s shape automatically, and compares it with principal component analysis (PCA), phase analysis, and kurtosis feature extraction methods for paint coated corrosion characterization and evaluation. The averaged skewness shows the best sensitivity for 0–6 months corrosion. The normalized second principal component (PC) presents good sensitivity and the best measurement scale for corroded time. Furthermore, the temperature curve analysis proves that the electrical conductivity dominates the induced heating and heat distribution. The corrosion height is utilized to explain why ECPT technique is valid within 10 months corroded time. ECPT technique is proved as a smart sensor system for paint coated corrosion detection and characterization.
Focus on the problem of multi-component in-situ on-line monitoring in fermentation, in this work, we proposed an on-line in-situ multi-channel detection flow path control system based on a novel enzyme electrode prepared from Prussian Blue (PB) nanomaterials. To match the detection behavior of this electrode, an innovative design of a multi-channel pump-valve synergistic flow path control system can effectively reduce cross-contamination and improve system reliability. According to the flow path detection logic requirements, software program modules, such as precise positioning and micro-injection of pipette needle, and calibration detection during the multi-component detection process, have been developed. Precise positioning and micro-injection of pipette needle were realized by the trapezoidal acceleration and deceleration algorithm combined with a subdivision drive circuit. For the continuous change glucose concentration in fermentation, an adaptive sampling strategy of the injection volume and calibration detection module were proposed to realize multi-component, wide-range from 1g/L to 180g/L, fast and accurate detection, which presenting the as-prepared in-situ on-line system was proved to exhibits a high accuracy with a low detection error (<2%) within the linear range.
In this paper, an ISFET sensor based on In2O3 nanoribbon is developed for pH detection of micro solutions. A double channel ISFET is designed which includes the In2O3 nanoribbon top channel and silicon substrate bottom channel so as to realize the pH detection of the micro solutions. Through experiments, the sensitivity of the sensor is 70 mV/pH in the range of pH 6 to pH 10, which exceeds the Nernst limit of 59.2 mV/pH (300 K) at room temperature. Taking the detection of cTnI as an example, the pH sensor can be used to detect the concentration of biomarkers
Here, a high-performance dual-gate ionsensitive field-effect transistor (ISFET) was designed for pH detection based on the high carrier mobility and chemical stability of In2O3. To optimize the structural parameters of the ISFET, the ISFET model with a dual-gate structure was constructed using the Silvaco TCAD. The effects of the channel layer and gate dielectric layer parameters on the performance of the ISFET model were investigated in the dual-gate structure. Following the optimal parameters of the simulation, the dual-gate ISFET chip was fabricated by microfabrication techniques. The pH sensitivity of the fabricated chip was 321.54 mV/pH and exhibited good stability with low drift and hysteresis voltage. In addition, we also tested the pH change caused by the hydrogen peroxide oxidation reaction under catalysis by horseradish peroxidase. The sensitivity was up to 103.28 µA/mM, verifying this high-performance ISFET can be used to detect pH changes of trace substances in the biosensing field.
The security of power grid is closely related to national security and social stability. With the development of smart grid and big data, grid data security has ushered in new challenges. The data provenance is one of the key issues. Considering the complexity of grid data storage types, this paper designs a virtual tuple-based data provenance scheme. This scheme firstly embedding the watermark with user identity through virtual tuple injection. Then, the data with watermark is distributed in the form of table splitting, which makes it possible to quickly locate the suspect user when a data leakage event occurs. Finally, the leaker is identified through watermark extraction and comparison. The simulation experiments show that our scheme has good robustness against insertion, replacement and deletion attacks.
Aimed at the stabilization problem of the Inertia Wheel Pendulum system, a recursive design method of stabilization controller is present. And a state feedback controller with explicit form was obtained. The stability of the closed loop system was analyzed by input-to-state stability. Finally, the effectiveness and performance of the proposed stabilization controllers for an inertia wheel pendulum system with parameters taken from a real-life model of the IWP is shown through simulations.
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