Abstract ：

A tungsten-rhenium (W-Re) thin film thermocouples (TFTCs) temperature sensor for ultra-high temperature detection is proposed to solve the problem of turbine inlet temperature measurement. The TFTCs is composed of silicon carbide (SiC) substrate, aluminium nitride (AlN) transition layer and W-Re3/W-Re25 alloy thermoelectric layer with a stacking structure. The thermoelectric characteristics and thermomechanical stability of the designed multi-layer heterogeneous films are simulated with the finite element simulation software. Combined with magnetron sputtering technology, the designed TFTCs is prepared and tested through the self-built calibration platform. The result shows that the fabricated TFTCs has excellent linearity and repeatability and can meet the requirements of stable, reliable and rapid response high temperature measurement.

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Abstract ：

In digital holography, the inherited speckle noise degrades imaging quality due to the coherent laser source. To overcome this problem, a hybrid method for speckle noise reduction is presented by combining a novel angular diversity approach with the block-matching and 3D filtering (BM3D) algorithm. A serial of holograms is first captured by the proposed recording approach, and then the image with high signal-to-noise ratio is obtained by averaging multiple reconstructed intensity images. Finally, the residual noise in the averaged image is further eliminated by the BM3D filtering algorithm. The speckle noise is significantly suppressed, and a nearly speckle-free image can be obtained. Experimental results demonstrate the effectiveness of the proposed method. (c) 2019 Optical Society of America

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Abstract ：

In this study, a simple auto-focusing algorithm to determine the focus plane in shape measurement using two-source digital holographic interferometry is presented. The wave fields corresponding to two illumination angles are reconstructed, and the correlation coefficient between two wave fields is calculated. This parameter is affected by the defocusing of the reconstruction image. Larger distances between the reconstruction plane and focus plane lead to smaller correlation coefficient. Because this relationship is independent of the strength of the feature patterns of a specimen, the focus plane can be automatically determined as the location of the maximum correlation coefficient without any artificial determination. Finally, the shape can be measured using two reconstructed wave fields of different illumination angle. Experiments have been conducted to demonstrate the feasibility of the proposed algorithm.

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auto-focusing correlation-coefficient holographic interferometry

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A near-infrared (nIR) light actuated tunable transmission optical grating based on graphene nanoplatelet (GNP)/polydimethylsiloxane (PDMS) and PDMS is proposed. A simple fabrication protocol is studied that allows integration of the grating with the actuation mechanism; both components are made from soft elastomers, and this ensure the tunability and the light-driven operation of the grating. The resulting grating structure demonstrates continuous period tunability of 2.7% under an actuation power density of 220 mW cm(-2) within a period of 3 s and also demonstrates a time-independent characteristic. The proposed infrared activated grating can be developed for wireless remote light splitting in bio/chemical sensing and optical telecommunications applications. (C) 2017 Elsevier B.V. All rights reserved.

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GNP/PDMS Graphene Grating Light-driven Tunable optics

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Abstract ：

This paper presents a multi-illumination lensless Fourier transform digital holographic interferometry method for surface shape measurement. In this method, the interference phases with different effective synthetic wavelengths are obtained by tilting the illumination angle several tunes, and all are wrapped. A Fourier-transform demodulation algorithm employing all these wrapped phases simultaneously is used to determine the object surface shape. No phase unwrapping procedure is required, and the shape information of each point is calculated independently, thereby offering great flexibility for measuring objects with discontinuities surface, such as holes, steps and gaps. Experimental results demonstrate the validity of the principle. (C) 2017 Elsevier B.V. All rights reserved.

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Interferometry Lensless digital holography Multi-illumination Shape measurement

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Abstract ：

We propose a multi-angle interferometry method for digital holographic metrology. In an application of three-dimensional (3D) reconstruction, the hologram corresponding to a different illumination angle is recorded as the illumination angle with a single wavelength tilted at regular intervals by an electronically controlled rotating stage. A Fourier-transform-based axial depth scanning algorithm formed by the reconstructed phase is used to obtain the height point by point over the whole field of view. Hence, the 3D reconstruction can be obtained effectively; even the object has large depth discontinuities resulting from the difficulty of the phase unwrapping. Due to a monochrome source only being used, the method is available for objects with wavelength-dependent reflectivity and those that are free of chromatic aberration caused by the different wavelengths. (C) 2016 Optical Society of America

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Background: Steady-state visually evoked potentials (SSVEPs) can be elicited by repetitive stimuli and extracted in the frequency domain with satisfied performance. However, the temporal information of such stimulus is often ignored. In this study, we utilized repetitive visual stimuli with missing events to present a novel hybrid BCI paradigm based on SSVEP and omitted stimulus potential (OSP). Methods: Four discs flickering from black to white with missing flickers served as visual stimulators to simultaneously elicit subject's SSVEPs and OSPs. Key parameters in the new paradigm, including flicker frequency, optimal electrodes, missing flicker duration and intervals of missing events were qualitatively discussed with offline data. Two omitted flicker patterns including missing black/white disc were proposed and compared. Averaging times were optimized with Information Transfer Rate (ITR) in online experiments, where SSVEPs and OSPs were identified using Canonical Correlation Analysis in the frequency domain and Support Vector Machine (SVM)-Bayes fusion in the time domain, respectively. Results and conclusions: The online accuracy and ITR (mean +/- standard deviation) over nine healthy subjects were 79.29 +/- 18.14 % and 19.45 +/- 11.99 bits/min with missing black disc pattern, and 86.82 +/- 12.91 % and 24.06 +/- 10.95 bits/min with missing white disc pattern, respectively. The proposed BCI paradigm, for the first time, demonstrated that SSVEPs and OSPs can be simultaneously elicited in single visual stimulus pattern and recognized in real-time with satisfied performance. Besides the frequency features such as SSVEP elicited by repetitive stimuli, we found a new feature (OSP) in the time domain to design a novel hybrid BCI paradigm by adding missing events in repetitive stimuli.

Keyword ：

Brain Computer Interface (BCI) Electroencephalogram (EEG) Omitted stimulus potential (OSP) Steady-state visually evoked potential (SSVEP)

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Epileptiform discharges recorded in the 4-aminopyridine (4-AP) in vitro epilepsy model are mediated by glutamatergic and GABAergic signaling. Using a 60-channel perforated multi-electrode array (pMEA) on corticohippocampal slices from 2 to 3 week old mice we recorded interictal- and ictal-like events. When glutamatergic transmission was blocked, interictal-like events no longer initiated in the hilus or CA3/CA1 pyramidal layers but originated from the dentate gyrus granule and molecular layers. Furthermore, frequencies of interictal-like events were reduced and durations were increased in these regions while cortical discharges were completely blocked. Following GABA(A) receptor blockade interictal-like events no longer propagated to the dentate gyrus while their frequency in CA3 increased; in addition, ictal-like cortical events became shorter while increasing in frequency. Lastly, drugs that affect tonic and synaptic GABAergic conductance modulated the frequency, duration, initiation and propagation of interictal-like events. These findings confirm and expand on previous studies indicating that multiple synaptic mechanisms contribute to synchronize neuronal network activity in forebrain structures. This article is part of a Special Issue entitled 'Trends in Neuropharmacology: In Memory of Erminio Costa'. (C) 2010 Elsevier Ltd. All rights reserved.

Keyword ：

4-Aminopyridine GABA Hippocampus Local field potentials Seizures

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Epilepsy is the most common neurological disorder in the world, second only to stroke. There are nearly 15 million patients suffer from refractory epilepsy, with no available therapy. Although most seizures are not life threatening, they are an unpredictable source of annoyance and embarrassment, which will result in unconfident and fear. Prediction of epileptic seizures has a profound effect in understanding the mechanism of seizure, improving the rehabilitation possibilities and thereby the quality of life for epilepsy patients. A seizure prediction system can help refractory patients rehabilitate psychologically. In this paper, we introduce an epilepsy seizure prediction algorithm from scalp EEG based on morphological filter and Kolmogorov complexity. Firstly, a complex filter is constructed to remove the artifacts in scalp EEG, in which a morphological filter with optimized structure elements is proposed to eliminate the ocular artifact. Then, the improved Kolmogorov complexity is applied to describe the non-linear dynamic transition of brains. Results show that only the Kolmogorov complexity of electrodes near the epileptogenic focus reduces significantly before seizures. Through the analysis of 7 long-term scalp EEG recordings from 5 epilepsy patients, the average prediction time is 8.5 minutes, the mean sensitivity is 74.0% and specificity is 33.6%.

Keyword ：

artifact removal epileptic seizure prediction kolmogorov complexity morphological filter scalp EEG

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Medium and small equipments in manufacturing are numerous, various and dispersive, so route inspection is the best method to acquire their condition information for its flexibility and low costs. In this paper, an integrated information system for route inspection is constructed to achieve distributed information acquisition on a large scale and centralized information management in a well order. Firstly, the information transfer model of route inspection is erected to describe information demands of route inspection participant. Then, several key problems, such as the instrument for information acquiring, information administration mode, interaction mode and security, are resolved respectively. Finally, three units, workstation, server and client are developed to acquire, manage and utilize the information. They are integrated into a whole system called MTREE, which has been applied into several steel enterprises successfully.

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