EMD-Based Symbolic Dynamic Analysis for the Recognition of Human and Nonhuman Pyroelectric Infrared Signals

In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR) signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD)-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector’s false alarms

PIMR: Parallel and Integrated Matching for Raw Data

With the trend of high-resolution imaging, computational costs of image matching have substantially increased. In order to find the compromise between accuracy and computation in real-time applications, we bring forward a fast and robust matching algorithm, named parallel and integrated matching for raw data (PIMR). This algorithm not only effectively utilizes the color information of raw data, but also designs a parallel and integrated framework to shorten the time-cost in the demosaicing stage. Experiments show that compared to existing state-of-the-art methods, the proposed algorithm yields a comparable recognition rate, while the total time-cost of imaging and matching is significantly reduced

Velocity Structure and Cu-Au Mineralization of the Duobaoshan Ore District, NE China: Constrained by First-Arrival Seismic Tomography

The genesis of deeply buried deposits in the Duobaoshan ore district, the largest porphyry-related Cu-Mo-Au ore field in northeastern China, is not well understood and their exploration is lacking because the fine velocity structure of this region is not comprehensively understood. Herein, first-arrival seismic travel times were picked along a deep seismic reflection profile and inverted using the tomographic method to obtain a detailed velocity profile of the upper 2900 m of the crust beneath this region. The profile showed that the velocity varied from 1900 to 6100 m/s and that the crust was subdivided into five parts by two low-velocity (2500–4000 m/s) blocks. Based on previous studies, the boundaries between the high-speed and low-speed bodies were interpreted as hidden fractures, and the 5000–6100 m/s parts were interpreted as concealed granite bodies in these sections. Porphyry copper deposits in the Duobaoshan ore district were related to the occulted granite bodies, and epithermal Au deposits were associated with the occulted fracture zones. Comprehensive evaluation of hydrothermal activity, regional magnetic anomalies, and deposit distribution indicated that the hidden fractures served as channels for ore-related magmas. Combining previous research on the Duobaoshan ore district with our results of the high-velocity interface, we infer that the prospecting range of the Tongshan deposit is below the depth of 1000 m

Velocity Structure and Cu-Au Mineralization of the Duobaoshan Ore District, NE China: Constrained by First-Arrival Seismic Tomography

The genesis of deeply buried deposits in the Duobaoshan ore district, the largest porphyry-related Cu-Mo-Au ore field in northeastern China, is not well understood and their exploration is lacking because the fine velocity structure of this region is not comprehensively understood. Herein, first-arrival seismic travel times were picked along a deep seismic reflection profile and inverted using the tomographic method to obtain a detailed velocity profile of the upper 2900 m of the crust beneath this region. The profile showed that the velocity varied from 1900 to 6100 m/s and that the crust was subdivided into five parts by two low-velocity (2500–4000 m/s) blocks. Based on previous studies, the boundaries between the high-speed and low-speed bodies were interpreted as hidden fractures, and the 5000–6100 m/s parts were interpreted as concealed granite bodies in these sections. Porphyry copper deposits in the Duobaoshan ore district were related to the occulted granite bodies, and epithermal Au deposits were associated with the occulted fracture zones. Comprehensive evaluation of hydrothermal activity, regional magnetic anomalies, and deposit distribution indicated that the hidden fractures served as channels for ore-related magmas. Combining previous research on the Duobaoshan ore district with our results of the high-velocity interface, we infer that the prospecting range of the Tongshan deposit is below the depth of 1000 m

High Performance Drain Engineered InGaN Heterostructure Tunnel Field Effect Transistor

A drain engineered InGaN heterostructure tunnel field effect transistor (TFET) is proposed and investigated by Silvaco Atlas simulation. This structure uses an additional metal on the drain region to modulate the energy band near the drain/channel interface in the drain regions, and increase the tunneling barrier for the flow of holes from the conduction band of the drain to the valence band of the channel region under negative gate bias for n-TFET, which induces the ambipolar current being reduced from 1.93 × 10−8 to 1.46 × 10−11 A/μm. In addition, polar InGaN heterostructure TFET having a polarization effect can adjust the energy band structure and achieve steep interband tunneling. The average subthreshold swing of the polar drain engineered heterostructure TFET (DE-HTFET) is reduced by 53.3% compared to that of the nonpolar DE-HTFET. Furthermore, ION increases 100% from 137 mA/mm of nonpolar DE-HTFET to 274 mA/mm of polar DE-HTFET

Physical and 3D Printing Properties of Arrowroot Starch Gels

This paper aims to investigate the physical and 3D printing properties of arrowroot starch (AS), a natural biopolymer with many potential health benefits. Scanning electron microscopy images showed that AS granules had mixed spherical and elongated geometries, with average sizes of 10.5 ± 2.5 μm. The molecular weight of AS measured by gel permeation chromatography (GPC) was 3.24 × 107 g/mol, and the amylose/amylopectin ratio of AS was approximately 4:11. AS has an A-type crystal structure, with a gelatinization temperature of 71.8 ± 0.2 °C. The overlap concentration (C*) of AS in aqueous solutions was 0.42% (w/v). Temperature-dependent dynamic rheological analyses of 10% to 30% (w/v) AS fluids showed that the storage modulus (G’) reached the maximum values around the gelatinization temperatures, while the yield stress (τy) and flow stress (τf) values all increased with the increase in AS concentration. The printing accuracy of AS gels was found to be associated with the interplay between the G’ values and the restorability after extrusion, determined by the three-interval thixotropy tests (3ITT). The optimum 3D printing condition occurred at 20% (w/v) AS, the nozzle diameter of 0.60 mm, the printing speed of 100 mm/s and the extrusion speed of 100 mm/s. Our research provides a promising biopolymer to be used in the design of novel personalized functional foods

Preparation and Applications of Electrospun Nanofibers for Wearable Biosensors

The emergence of nanotechnology has provided many new ideas and innovations in the field of biosensors. Electrospun nanofibers have many excellent properties such as high specific surface area, high porosity, low cost, high efficiency, and they can be combined with a variety of sensors. These remarkable features have a wide range of applications in the field of sensors such as monitoring air pollutants, highly sensitive pressure sensors, and biosensors for monitoring the pulse of the body. This paper summarizes the working principle and influencing factors of electrospinning nanofibers, and illustrates their applications in wearable biosensors

Gate-Tunable Electronic Structure of Black Phosphorus/HfS₂ P–N van der Waals Heterostructure with Uniformly Anisotropic Band Dispersion

Black phosphorus (BP)-based heterostructure with tunable band offset has been proven to be promising for rectifier diode and photoelectronic devices. However, it is usually not easy to find a suitable material to construct the heterojunction because the necessary type-II band structure and the strong unintentional p-type doping of BP should be both considered. Therefore, most of studies mainly focused on certain 2D materials, like MoS₂ and WSe₂. However, the low mobility of these materials greatly hinders the further promotion of device performance. For the first time, we demonstrate that HfS₂, which has been proven to possess a much higher mobility of electrons and has been experimentally synthesized recently, fully satisfies conditions of heterostructure with BP. The heterojunction could be used as a tunable optoelectronic device and rectifier diode. With external normal electric field, the efficiency of photon-generated charge separation and rectification ratio could be manipulated. In addition, what is interesting is that the nanostructure presents an unexpected highly anisotropic band dispersion along orthogonal directions, which suggests a superior transport performance with both high mobility and carrier density