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In this paper, a third-order S-curve is used to model the motion issue. A closed method of solving is derived for the optimal point-to-point(P2P) time issue based on the model. Based on the P2P time-optimal solution, a closed multi-axis synchronization algorithm (MASA) method is proposed. This method considers the kinematic equation of the S-curve based on the inverse function of the multivariate function. Therefore, the inverse function of the execution time is derived via the kinematic equation of the P2P time optimization issue and solving a set of smaller bandwidth parameters is an important attempt in this paper. Otherwise, based on the MASA proposed in this paper, a synchronous computing framework suitable for the planning of robot space poses was designed. This framework can effectively solve problems with robot pose planning. The innovations of this article can be summarized as:(1)Based on the third-order S-curve, this paper deduced a complete method for solving the P2P time-optimal curve.(2) Based on the method for solving the time-optimal curve, this paper further derived three synchronization methods based on time constraints.(3) Based on the MASA proposed in this paper, a synchronous computing framework suitable for the planning of robot space poses was designed. The continuity and smoothness of the robot joint spatial motion can be guaranteed in the Descartes space. Few scholars have studied the closed solution method of multi-axis synchronization. The research in this paper promotes the theoretical research of motion control.

Hypertension is a major cardiovascular risk factor for atrial fibrillation (AF) worldwide. However, the role of mechanical stress caused by hypertension on downregulating the L-type calcium current (ICa,L), which is vital for AF occurrence, remains unclear. Therefore, the aim of the present study was to investigate the role of Piezo1, a mechanically activated ion channel, in the decrease of ICa,L in response to high hydrostatic pressure (HHP, one of the principal mechanical stresses) at 40 mmHg, and to elucidate the underlying pathways. Experiments were conducted using left atrial appendages from patients with AF, spontaneously hypertensive rats (SHRs) treated with valsartan (Val) at 30 mg/kg/day and atrium-derived HL-1 cells exposed to HHP. The protein expression levels of Piezo1, Calmodulin (CaM), and Src increased, while that of the L-type calcium channel a1c subunit protein (Cav1.2) decreased in the left atrial tissue of AF patients and SHRs. SHRs were more vulnerable to AF, with decreased ICa,L and shortened action potential duration, which were ameliorated by Val treatment. Validation of these results in HL-1 cells in the context of HHP also demonstrated that Piezo1 is required for the decrease of ICa,L by regulating Ca2+ transient and activating CaM/Src pathway to increase the expression of paired like homeodomain-2 (Pitx2) in atrial myocytes. Together, these data demonstrate that HHP stimulation increases AF susceptibility through Piezo1 activation, which is required for the decrease of ICa,Lvia. the CaM/Src/Pitx2 pathway in atrial myocytes.

Abstract Supercritical CO2 (SCCO2) is considered as a promising alternative heat extraction fluid in the enhanced geothermal system (EGS) which can reduce atmospheric CO2 emissions and water waste. However, the heat extraction performance of SCCO2 is greatly affected by its thermophysical properties, which are high sensitivity to temperature/pressure. In this study, by considering the impacts of temperature and pressure on thermophysical properties of SCCO2, a thermo‐hydro‐mechanical coupling numerical model was established to investigate the effects of the initial reservoir temperature as well as the SCCO2 injection pressure and temperature on heat extraction. The variations of reservoir permeability and mass productivity as well as the net heat extraction rate (HER) were simulated by implementing the model into COMSOL Multiphysics, which showed a good consistency compared with the high‐temperature/pressure triaxial seepage experiments. Simulation results indicate that there are three distinct stages in mass productivity including the slow decline stage, the rapid increase stage, and the stabilization stage. Increasing the initial reservoir temperature or the injection temperature will reduce the net HER to varying degrees. Appropriate increase of the injection pressure and injection temperature can extend Stage 2 duration which can subsequently enhance the mass productivity and the net HER. Meanwhile, the higher injection pressure or the lower injection temperature will inhibit heat compensation within rock masses and accelerate the reservoir heat depletion. This study provides guidance for optimizing the injection parameters of CO2‐EGS and aims to enhance the net HER while ensuring a reasonable reservoir production life.

Efficient detection of single optical centres in solids is essential for quantum information processing, sensing and single-photon generation applications. In this work, we use radio-frequency (RF) reflectometry to electrically detect the photoionisation induced by a single Er3+ ion in Si. The high bandwidth and sensitivity of the RF reflectometry provide sub-100-ns time resolution for the photoionisation detection. With this technique, the optically excited state lifetime of a single Er3+ ion in a Si nano-transistor is measured for the first time to be |$0.49 \pm 0.04\ \mu$| s. Our results demonstrate an efficient approach for detecting a charge state change induced by Er excitation and relaxation. This approach could be used for fast readout of other single optical centres in solids and is attractive for large-scale integrated optical quantum systems thanks to the multi-channel RF reflectometry demonstrated with frequency multiplexing techniques. [ABSTRACT FROM AUTHOR]

Reliability of an electronic device, concerning if it can function reliably over its designated lifetime in the field (such as 10 or 15 years), has become more and more important in today's safety-critical applications such as automotive electronics. Traditionally, the ageing has been performed in an offline setting where stress test has been applied to accelerate the ageing process and then a model is established to make the futuristic prediction. This kind of offline method has a drawback of not being able to take into account the factor of the unique operating condition and environment that a device could have experienced in the field. In this work, we present the first cloud-based ageing monitoring system to the best of our knowledge, for the Internet-of-Things (IoT) devices. It has many advantages. First of all, one can know of the ageing status of an IoT device remotely and continuously. Secondly, through data analysis in a cloud server, more accurate prediction can be achieved. Thirdly, an ageing hazard can be alarmed in advance before it actually strikes, and thereby pre-caution actions (such as online repair, or even call-for-maintenance request) can be taken in advance to avoid unnecessary system fatal failure. A prototype system using test chips with built-in design-for-ageing-monitoring circuitry will be demonstrated with measurement data collected through a cloud server.

Abstract Hollow grouted rock bolts are widely used in deep soft rock roadways. The density of grout has a significant influence on the anchorage quality. However, there is still a lack of effective methods to detect the grouting quality fast, accurately, and extensively. Based on the wave velocity and the law of stress wave transmission and reflection in the impedance mismatch, non-destructive experiment focused on the defect in the anchorage was conducted. The wavelet transform was used to analyze the test signals. The test results show that the free length of hollow grouted rock bolt could be accurately detected through the analysis of the stress wave signal by using the low-pass filter in the wavelet toolbox. The grouted length, defect length, and specific position of the anchorage section can be accurately detected through the analysis of the stress wave signal by using the high-pass filter in the wavelet toolbox. The research can provide experiment foundation for further study of grouting quality based on the non-destructive methods.

It is of great significance for the sustainable development of global energy to develop hot dry rock (HDR) geothermal resources by using enhanced geothermal system (EGS) technology. Different working fluids in EGS have different heat recovery efficiencies. Therefore, this paper takes water and CO2 as the heat-carrying media and establishes a thermal hydraulic mechanical coupling model to simulate the heat recovery process in high-temperature rock mass. By considering the different confining pressures, rock temperature, and injection pressure, the advantages of H2O-EGS and CO2-EGS are obtained. The results show that with the increase of confining pressure, the heat recovery efficiency of water is significantly higher than that of CO2, but at higher reservoir temperature, CO2 has more advantages as a heat-carrying medium. The net heat extraction rate will increase with the increase of injection pressure, which indicates that the mass flow rate plays a leading role in the heat recovery process and increases the injection pressure of fluid which is more conducive to the thermal recovery of EGS. This study will provide a technical guidance for thermal energy exploitation of hot dry rock under different geological conditions.

JAK1 depletion or downregulation was previously reported to account for coronavirus inhibition. Here, we found that AG1024, an IR (insulin receptor) and IGF-1R (insulin-like growth factor 1 receptor) inhibitor, diminishes JAK1 protein levels and exerts anti-coronaviral activities with EC50 values of 5.2 ± 0.3 μM against transmissible gastroenteritis coronavirus (TGEV) and 4.3 ± 0.3 μM against human flu coronavirus OC43. However, although the IR and IGF-1R signaling pathways are activated by insulin or IGF-1 in swine testis cells, they are not triggered upon TGEV infection. AG1024, therefore, inhibits coronaviral replication and downregulates JAK1 protein levels independently of IR and IGF-1R. Moreover, JAK1 proteolysis caused by AG1024 was found through activation of upstream Ndfip1/2 and its effector NEDD4-like E3 ligase Itch. In addition, ouabain, which was reported to mediate JAK1 proteolysis causing anti-coronaviral activity by activation of Ndfip1/2 and NEDD4 E3 ligase, additively inhibited anti-coronaviral activity and JAK1 diminishment in combination with AG1024. This study provides novel insights into the pharmacological effects of AG1024 and Itch E3 ligase mediated JAK1 proteolysis and identified Ndfip1/2 as a cognate effector for JAK1 proteolysis via the diversified E3 ligases NEDD4 and NEDD4-like Itch. These findings are expected to provide valued information for the future development of anti-viral agents.