Design of Intelligent Voice Acquisition System Based on Cloud Resource Scheduling Model

The existing acquisition system has the problem of imperfect communication link, which leads to the weak signal receiving strength of the system. This paper designs an intelligent voice acquisition system based on cloud resource scheduling model. Hardware: select S3C6410 as hardware platform, optimize audio access port, connect IIS serial bus and other components; Software part: extract the frequency agility characteristics of intelligent voice signal, predict the future sample value, establish the communication link with cloud resource scheduling model, obtain the communication rate information, code and generate digital voice data, set the transmission function of intelligent acquisition system with overlay algorithm. Experimental results: the average signal receiving strength of the designed system and the other two intelligent voice intelligent acquisition systems is 106.40 dBm, 91.33 dBm and 90.23 dBm, which proves that the intelligent acquisition system integrated with cloud resource scheduling model has higher use value.

Analytical models for inter-layer tunneling in two-dimensional materials

Analytical formula of the transmission function of the inter-layer intra-band tunneling is derived for coupled narrow two-dimensional materials. Analytical models of the intra-band tunneling conductance G, the transmission function of the inter-layer band-to-band tunneling, and the maximum band-to-band tunneling current Imax, are also obtained. G and Imax are shown to exhibit different characteristics depending on the channel length.

New route to enhanced figure of merit at nano scale: effect of AAH modulation

We report, for the first time, the phenomenon of thermoelectricity at quantum level considering a correlated disordered tight-binding (TB) one-dimensional lattice where site energies and/or nearest-neighbor hopping integrals are modulated in the cosine form following the well known Aubry-Andre-Harper (AAH) model. The atypical gapped and fragmented energy spectrum yields a transmission function whose steepness is not symmetrical around Fermi energy, and because of this fact, we obtain a reasonably large figure of merit, a quantity that measures the thermoelectric energy conversion efficiency. The efficiency can be further monitored by means of AAH phase(s) which undoubtedly gives a possible route of designing controlled thermoelectric devices. Evaluating transmission probabilities using the Green's function formalism, we compute all the thermoelectric quantities based on the Landauer integrals. The diagonal, off-diagonal and generalized versions of the AAH model are taken into account, and in all the cases we find favorable thermoelectric response. At the end of our analysis, we discuss briefly the specific role of phonon thermal conductance on thermoelectric efficiency to make the present investigation a self-contained one. Our theoretical study may shed some light in analyzing thermoelectric phenomena in similar kind of quasicrystals and other related systems.

Study on Design of Novel Function/Structure Integration Mounting Plate for Space borne SAR Antenna for Wireless Communication

A novel lightweight and high-precision synthetic aperture radar (SAR) antenna mounting plate scheme based on functional structure integration technology is proposed. The thermal control function, high and low frequency blind insertion signal transmission function of the system are combined with the antenna structure to greatly reduce the size and weight of SAR antenna. The design verification of a high-density integrated SAR antenna mounting plate breaks through the key process technologies such as accurate splicing of multiple interfaces of the mounting plate, highly reliable cementation of non-uniform honeycomb and large-scale warpage control, and solves the key technical difficulties of high precision, high temperature and high reliability. The results show that the antenna mounting plate (size 649mm × 430mm) the overall flatness is better than 0.28mm, the thickness limit dimension deviation is less than 0.1mm, and the temperature consistency is less than 1.8°C. It can meet the requirements of lightweight, structural stiffness and strength, RF blind plug connection and heat dissipation for space borne SAR antenna.

IoT Enabled Ventilator Monitoring System for Covid-19 Patients

The use of the IoT protocol on medical equipment is expected to provide protection for medical personnel in dealing with Covid-19 patients, especially when medical personnel are monitoring and setting up an equipment. This study aims to (1) produce a monitoring and control system for a breathing apparatus (Ventilator) based on the Internet of Thing (IoT), (2) test the ventilator control function, (3) test the data transmission function with the IoT protocol. The method used is Define, Design, Develop, and Disseminate (4D). Data collection is done through (1) Testing and Observation (2) Limited field test. This research produces a control and monitoring system for mechanical ventilators. The mechanical ventilator consists of a gripper motion mechanism driven by a dc motor. The movement of the gripper creates pressure and releases pressure on the ambu bag. The depth of pressure exerted by the gripper is measured as the volume and pressure of the air delivered to the lungs. The rate of pressure exerted is measured as the velocity of air flowing into the lungs.

Spin thermoelectric effects of new-style one-dimensional carbon-based nanomaterials

Based on first-principles methods, the authors of this paper investigate spin thermoelectric effects of one-dimensional spin-based devices consisting of zigzag-edged graphene nanoribbons (ZGNRs), carbon chains and graphene nanoflake. It is found that the spin-down transmission function is suppressed to zero, while the spin-up transmission function is about 0.25. Therefore, an ideal half-metallic property is achieved. In addition, the phonon thermal conductance is obviously smaller than the electronic thermal conductance. Meantime, the spin Seebeck effects are obviously enhanced at the low-temperature regime (about 80K), resulting in the fact that spin thermoelectric figure of merit can reach about 40. Moreover, the spin thermoelectric figure of merit is always larger than the corresponding charge thermoelectric figure of merit. Therefore, the study shows that they can be used to prepare the ideal thermospin devices.

System Performance Analysis for Trimmable Horizontal Stabilizer Actuator Focusing on Nonlinear Effects: Based on Incremental Modelling and Parameter Identification Methodology

With the development of more/all electric aircraft, replacement of the traditional hydraulic servo actuator (HSA) with an electromechanical actuator (EMA) is becoming increasingly attractive in the aerospace field. This paper takes an EMA for a trimmable horizontal stabilizer as an example and focuses on how to establish a system model with an appropriate level of complexity to support the model-based system engineering (MBSE) approach. To distinguish the nonlinear effects that dominate the required system performance, an incremental approach is proposed to progressively introduce individual nonlinear effects into models with different complexity levels. Considering the special design and working principle of the mechanical power transmission function for this actuator, the nonlinear dynamics, including friction and backlash from the no-back mechanism, and the nonlinear compliance effect from the mechanical load path are mainly taken into consideration. The modelling principles for each effect are addressed in detail and the parameter identification method is utilized to model these nonlinear effects realistically. Finally, the responses from each model and experimental results are compared to analyze and verify how each individual nonlinearity affects the system’s performance.

Understanding the Functional Expression of Na+-Coupled SLC4 Transporters in the Renal and Nervous Systems: A Review

Acid-base homeostasis is crucial for numerous physiological processes. Na+/HCO3− cotransporters (NBCs) belong to the solute carrier 4 (SLC4) family, which regulates intracellular pH as well as HCO3− absorption and secretion. However, knowledge of the structural functions of these proteins remains limited. Electrogenic NBC (NBCe-1) is thought to be the primary factor promoting the precise acid–base equilibrium in distinct cell types for filtration and reabsorption, as well as the function of neurons and glia. NBC dysregulation is strongly linked to several diseases. As such, the need for special drugs that interfere with the transmission function of NBC is becoming increasingly urgent. In this review, we focus on the structural and functional characteristics of NBCe1, and discuss the roles of NBCe1 in the kidney, central nervous system (CNS), and related disorders, we also summarize the research on NBC inhibitors. NBCe1 and the related pathways should be further investigated, so that new medications may be developed to address the related conditions.

S-Ketamine Exerts Antidepressant Effects by Regulating Rac1 Gtpase Mediated Synaptic Plasticity in the Hippocampus of Stressed Rats

Clinical studies have found that ketamine has a rapid and lasting antidepressant effect, especially in the case of patients with major depressive disorder (MDD). The molecular mechanisms, however, remain unclear. In this study, we observe the effects of S-Ketamine on the expression of Rac1, neuronal morphology, and synaptic transmission function in the hippocampus of stressed rats. Chronic unpredictable mild stress (CUMS) was used to construct stressed rats. The rats were given a different regimen of ketamine (20mg/kg, i.p.) and Rac1 inhibitor NSC23766 (50µg, ICV) treatment. The depression-like behavior of rats was evaluated by sucrose preference test and open-field test. The protein expression of Rac1, Glur1, synapsin1, and PSD95 in the hippocampus was detected by Western blot. Pull-down analysis was used to examine the activity of Rac1. Golgi staining and electrophysiological study were used to observe the neuronal morphology and long-term potentiation (LTP). Our results showed that ketamine can up-regulate the expression and activity of Rac1; increase the spine density and the expression of synaptic-related proteins such as Glur1, Synapsin1, and PSD95 in the hippocampus of stressed rats; reduce the CUMS-induced LTP impairments; and consequently improve depression-like behavior. However, Rac1 inhibitor NSC23766 could have effectively reversed ketamine-mediated changes in the hippocampus of rats and counteracted its antidepressant effects. The specific mechanism of S-ketamine's antidepressant effect may be related to the up-regulation of the expression and activity of Rac1 in the hippocampus of stressed rats, thus enhancing synaptic plasticity.