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Objective. The aim of this study is to investigate continuous blood pressure waveform estimation from a plethysmography (PPG) signal, thus providing more human cardiovascular status information than traditional cuff-based methods. Approach. The proposed method utilizes the feature extraction ability of a convolution neural network to estimate blood pressure (BP) from PPG signals without the need for waveform analysis and signal feature extraction. Main results. The network achieved mean absolute errors and standard deviations of 2.55 ± 3.92 mmHg for systolic BP (SBP), 1.66 ± 2.76 mmHg for diastolic BP (DBP), and 2.52 ± 3.02 mmHg for overall pressure waveform. The results meet the best levels of the protocols of the British Hypertension Society (BHS) and the Association for the Advancement of Medical Instrumentation (AAMI). Significance. The proposed method shows promise for noninvasive continuous BP monitoring in hospital wards and daily life, which can assist in clinical diagnosis, disease treatment, and rehabilitation.

New energy storage is an important technology and fundamental equipment for building a new electric power system, an important support for achieving the goals of carbon peaking and carbon neutrality, and also a development focus for emerging strategic industries. In light of typical situations, such as a lack of station site resources and large-scale access to distributed new energy for power supply on a sea island, new energy storage is proposed to solve power supply capacity or quality problems in local areas and to replace or postpone power transmission and distribution investment. Considering the different life cycles of energy storage and power grid facility projects, we proposed an assessment method for the substitution effect of alternative energy storage on power grid functions based on the annual cost method and measured its cost-effectiveness under typical application scenarios.

A Muon station for sciEnce, technoLOgy and inDustrY (MELODY) has been listed in the China Spallation Neutron Source upgrade plan, and the infrastructure construction is scheduled to start by the end of 2022. The 1.6 GeV double-pulsed proton bunch will be extracted from the Rapid Cycling Synchrotron (RCS) ring to a stand-alone target station. One surface muon and one decay muon beamline are designed to provide multi-terminals for applications. In this report, we describe the design of MELODY and prospect for future applications.

The Phase II upgrade project of the China Spallation Neutron Source (CSNS) includes the construction of a surface muon beam line and a muon spin rotation/relaxation/resonance (μSR) spectrometer, which will be the first μSR spectrometer built in China. Here, we report the conceptual design of the spectrometer, including the detector arrangement, magnets, sample environment (SE) and sample chamber. Based on the design parameters of the muon beam (1 Hz, 105 μ+/pulse), the spectrometer possesses over 2500 detector units to maximize the counting rate. Three different types of magnets can generate a zero field (ZF), a longitudinal field (LF) within 5000 G, and a transverse field within 400 G. The SE consists of a cryostat and a closed-cycle refrigerator (CCR) to provide temperatures lower than 2 K in the current stage. It has potentials to be updated to 300 mK. The sample chamber is designed with a fly past structure to reduce the background for experiments with small-sized samples.

The reverse gate leakage mechanism of W-gate and TiN-gate AlGaN/GaN high-electron-mobility transistors (HEMTs) with N2 plasma surface treatment is investigated using current–voltage (I–V) and capacitance–voltage (C–V) characteristics and theoretical calculation analysis. It is found that the main reverse gate leakage mechanism of both devices is the trap-assisted tunneling (TAT) mechanism in the entire reverse bias region (–30 V to 0 V). It is also found that the reverse gate leakage current of the W-gate AlGaN/GaN HEMTs is smaller than that of the TiN gate at high reverse gate bias voltage. Moreover, the activation energies of the extracted W-gate and TiN-gate AlGaN/GaN HEMTs are 0.0551 eV–0.127 eV and 0.112 eV–0.201 eV, respectively.

The Resistive Plate Chamber (RPC) are widely used in high energy physics (HEP) experiments. In recent years, new designs and application scenarios of RPCs abound, and an advanced time-to-digital converter (TDC) system is in demand. The TDC implemented in the field-programmable gate array (FPGA) is widely used in HEP experiments with changeable conditions as a flexible time measurement method. This article presents a multi-phase shift-clock sampling FPGA-based TDC with 128 channels. The TDC module is implemented in a Xilinx Kintex-7 FPGA. The sampling clock period (2.22 ns) is subdivided into 24 phases to achieve finer time resolution. The TDC performance measurements show that the root-mean-square (RMS) time resolution of the TDC module in the time interval measurement is 45.3 ∼ 57.7 ps, and the integral nonlinearity (INL) is smaller than 0.2368 least significant bit (LSB). In addition, some target designs are made to adapt to the application scenarios. This article also shows measurement results acquired from an RPC by this TDC. This TDC was used to measure the RPC efficiency plateau and the TOT of the RPC readout signal.

Monochromator plays a key role in the performance of a synchrotron beamline, it determines a beamline’s energy range, bandwidth, flux, focal sizes, coherence, etc., and it has been the limiting optic in a beamline for a long time. Many efforts have been made in order to improve the performance of the monochromators around the world. The HEPS project will need a batch of monochromators and some of them are built in house, many technical problems needed to be solved. A double crystal monochromator prototype has been developed, tested, then modified by improving the mechanical stability, switching to mechanism based on flexures to drive the second crystal. A quick EXAFS Channel-Cut crystal monochromator was designed for the HEPS XAFS beamline, driven by torque motor and closed loop controller. The design aspects and some test results of both monochromators will be introduced. Results show that the design is feasible and meet the requirements of both beamlines.

Blockchain was combined with several other information technologies and computing concepts to create modern cryptocurrencies protecting through cryptographic mechanisms instead of a central repository or authority. A Framework of distributed solar Blockchain Service (DSBaaS) platform as a Service is designed to manage distributed solar energy system by adopting Blockchain as a Service (BaaS) platform. Base on the ability operation and maintenance features of BaaS, it is available to solve operational management, safety management, material management, project management, financial transactions management, transaction settlement and other related multi-agent transaction pain points. Providing new business models for implementing distributed solar energy production, transmission and utilization of effective coordination and management, it is a key component to forming clean, efficient, flexible and intelligent distributed solar energy system.

Structural stability in terms of the decomposition temperature in LiMn2O4 was systematically investigated by a series of high-temperature and high-pressure experiments. LiMn2O4 was found to have structural stability up to 5 GPa at room temperature. Under ambient pressure, the compound decomposed at 1300 °C. The decomposition temperature decreased with increasing pressure, yielding more complex decomposed products, Below the decomposition temperature, the crystal structure of LiMn2O4 varied with pressure. The presented results in this study offer new insights into the thermal and pressure stability of LiMn2O4 materials as a cathode for lithium-ion batteries that can operate under extreme conditions. Therefore, these findings may serve as a useful guide for future work for improving lithium-ion batteries.

The paper analyzes the advantages and disadvantages of the existing information service methods in the tunnel, and proposes the use of full-band FM broadcast for emergency information release. It can also cooperate with other systems to achieve integrated information release. This achievement forwards FM signals outside the tunnel in daily situations, and uses full-band FM to implement emergency information insertion in emergency situations, which not only improves the daily information service level but also implements the function of emergency warning, and effectively improves the level of tunnel safety.

Strain and stress were simulated using finite element method (FEM) for three III–V-on-Insulator (III–VOI) structures, i.e., InP/SiO2/Si, InP/Al2O3/SiO2/Si, and GaAs/Al2O3/SiO2/Si, fabricated by ion-slicing as the substrates for optoelectronic devices on Si. The thermal strain/stress imposes no risk for optoelectronic structures grown on InPOI at a normal growth temperature using molecular beam epitaxy. Structures grown on GaAsOI are more dangerous than those on InPOI due to a limited critical thickness. The intermedia Al2O3 layer was intended to increase the adherence while it brings in the largest risk. The simulated results reveal thermal stress on Al2O3 over 1 GPa, which is much higher than its critical stress for interfacial fracture. InPOI without an Al2O3 layer is more suitable as the substrate for optoelectronic integration on Si.

As one of important members of refractory materials, tungsten phosphide (WP) holds great potential for fundamental study and industrial applications in many fields of science and technology, due to its excellent properties such as superconductivity and as-predicted topological band structure. However, synthesis of high-quality WP crystals is still a challenge by using tradition synthetic methods, because the synthesis temperature for growing its large crystals is very stringently required to be as high as 3000 °C, which is far beyond the temperature capability of most laboratory-based devices for crystal growth. In addition, high temperature often induces the decomposition of metal phosphides, leading to off-stoichiometric samples based on which the materials’ intrinsic properties cannot be explored. In this work, we report a high-pressure synthesis of single-crystal WP through a direct crystallization from cooling the congruent W–P melts at 5 GPa and ∼ 3200 °C. In combination of x-ray diffraction, electron microscope, and thermal analysis, the crystal structure, morphology, and stability of recovered sample are well investigated. The final product is phase-pure and nearly stoichiometric WP in a single-crystal form with a large grain size, in excess of one millimeter, thus making it feasible to implement most experimental measurements, especially, for the case where a large crystal is required. Success in synthesis of high-quality WP crystals at high pressure can offer great opportunities for determining their intrinsic properties and also making more efforts to study the family of transition-metal phosphides.

The Yangtze River Economic Belt has gradually become one of the regions with the strongest comprehensive strength and the greatest strategic competitiveness in China. Promoting the utilization efficiency of water resources in various provinces and cities in this region and minimizing the restraint effect of insufficient utilization of water resources on the economy can provide strong support for the development of the region from the perspective of water resources. The SBM model was used to measure the water use efficiency of 11 provinces and cities in the Yangtze River Economic Zone from 2007 to 2017 and Tobit model was used to identify the key influencing factors. The results show that the water use efficiency of the provinces and cities in the Yangtze River Economic Zone varies greatly, and the total factor productivity index of water resources shows an overall growth trend, which is mainly determined by the scale efficiency. The per capita GDP and the proportion of the first industry have a significant positive effect on the water use efficiency, while the government’s investment in water resources and per capita water resources endowment have a significant negative correlation. Based on this, some countermeasures and suggestions are put forward, such as strengthening inter-regional technical cooperation, optimizing water use structure, and reasonably investing in water conservancy facilities projects.

Compared with discrete variable quantum key distribution, continuous variable quantum key distribution (CVQKD) has the advantages of low cost, good stability, and high channel capacity, in addition to unconditional security and detectability for wiretapping. The basis of CVQKD system operation is the realization of loading information into photon quantum states. In this paper, a laser light source control system has realized the control and adjustment of the photon quantum states and completed the encoding of quantum states. In order to generate synchronous optical signals, FPGA, multi-channel DAC and micro power ADC are used to control the source of the synchronous optical laser. The control and modulation of multiple optical components are realized based on FPGA, multiple 16-bit 1.0 GSPS DACs and high-performance operational amplifiers. The electronic test results show that the system implements the control and adjustment functions of lasers, amplitude modulator, phase modulators, variable optical attenuators, polarization controllers, as well as detection of synchronized light. The performance of the laser light source control system fully meets the requirements of the CVQKD system.

In order to digitize the High-Frequency signal, a 12-bit 1Gsps RF Sampling data acquisition system is designed. The digital acquisition system includes an Analog-to-Digital Converter (ADC) daughter card and a data processing mother card equipped with Field Programmable Gate Arrays (FPGA) for communication, which has an external DDR3 memory module and a Gigabit Ethernet Interface. It focuses on the hardware system implementation of the daughter card and the realization of data receiving, transferring, and sending based on the FPGA. The test results show that the Effective Number of Bit (ENOB) of the acquisition card is above 9.1 Bits. Both Integral Non-Linear (INL) and Differential Non-Linearity (DNL) are anticipated. It accomplishes the requirements for engineering applications in many fields excellently.

Synopsis The electron displacement induced by an ultrashort pulse is theoretically investigated. We propose and numerically demonstrate a scheme to accurately measure the electron displacement using a ruler formed by the interfering spirals in the photoelectron momentum distribution generated by two oppositely circularly polarized pulses. It can be understood as a temporal double-slit with an additional spatial shift on one slit.

We develop a time-dependent perturbation theory (PT) beyond the dipole approximation to analyze the two-photon ionization dynamics of atoms exposed to short laser pulses with an arbitrary polarization. In a wide range of laser parameters, the good performance of the PT method is validated by comparing the results of a number of physical quantities with those calculated by numerically solving the time-dependent Schr\"odinger equation beyond the dipole approximation. Subsequent applications of the PT method in the nonresonant regime allow us to unveil the important role of the interferences between the dipole and nondipole transition pathways to the photoelectron momentum shift along the laser-propagation direction. In particular, we find that the ratio of the probability of each dipole transition channel to the total ionization probability oscillates with the increase of the photon energy. The interferences among different pathways and the oscillatory behavior of the ratios jointly lead to a series of minima in the linear momentum transfer for the case of the linear polarization.

In this review, we will focus on recent progress on the investigations of nondipole effects in few-electron atoms and molecules interacting with light fields. We first briefly survey several popular theoretical methods and relevant concepts in strong field and attosecond physics beyond the dipole approximation. Physical phenomena stemming from the breakdown of the dipole approximation are then discussed in various topics, including the radiation pressure and photon-momentum transfer, the atomic stabilization, the dynamic interference, and the high-order harmonic generation. Whenever available, the corresponding experimental observations of these nondipole effects are also introduced respectively in each topics.

In the microgrid system, the power supply quality of sensitive loads is directly affected by the grid-connected and off-grid operation states of the energy storage power supply as well as the dynamic switching process between the two states. To solve this problem, this paper adopts a control method of energy storage inverter based on virtual synchronous generator, which makes the energy storage inverter equivalent to a controlled voltage source with functions of inertia simulation, frequency modulation and voltage regulation. Besides, a seamless switching control strategy of energy storage inverter is proposed, which can realize the automatic smooth switching of the grid-connected state, off-grid state and state between the two.

An experimental muon source (EMuS) to provide a very intense muon beam has been studied at the China Spallation Neutron Source (CSNS) since 2007 and will be operational in the next few years. R&D efforts including a 128-channel muon spin rotation, relaxation, and resonance (μSR) spectrometer prototype are also ongoing. A data acquisition (DAQ) system was been developed to run the μSR spectrometer prototype on the EMuS. It includes front-end electronics (FEEs), time-to-digital converter (TDC) modules, and a DAQ software. The raw data acquired by the DAQ software were converted into a specific format and submitted to specialized analysis software for analysis. The DAQ system was tested on the ISIS muon beam, and the test results proved its performance.

The prototype Resistive Plate Chamber (RPC) has been made for the ATLAS phase II upgrade. The beam-test results showed that its cluster size is larger than expected. To figure out the causes, we developed a new approach in simulating RPC which based on Computer Simulation Technology (CST) Suite. The influences from the surface resistivity of the graphite layer and other characteristics have been studied. Comparisons between the simulation data and the beam-tests results have also been performed.

The design of an experimental muon source (EMuS) at the China Spallation Neutron Source (CSNS) has been underway for muon spin rotation, relaxation and resonance (μSR) experiments since 2007. A 128-channel μSR spectrometer prototype is also being developed. We have successfully developed a 32-channel time-to-digital converter (TDC) electronic readout unit module for the μSR spectrometer prototype. It receives timing signals from four front-end electronics (FEEs) and communicates with them. Moreover, it is a standard NIM module with a single field-programmable gate array-based design that meets the following requirements for μSR experiments: a low dead time, an instantaneous high count rate, a relatively long measurement duration, a relatively high resolution, and multiple channel-compatibility. By incorporating look-up tables (LUTs), placement constraints and area constraints, the routing skew of all TDC channels is reduced to less than 4 ps. Furthermore, Gigabit Ethernet data transmission has been incorporated in anticipation of more channels being added in the future.

EMuS (Experimental Muon Source) as the first muon source in China will be built at China Spallation Neutron Source (CSNS). A 128-channel μSR spectrometer prototype is under development for EMuS. As the core part of μSR spectrometer prototype, the detection system (detectors and readout electronics) has been constructed. Beam test (at ISIS Muon Source in U.K.) and magnetic shielding test have been carried out to test the performances of this detection system. In this paper, a new test method has been developed to test the magnetic shielding capability by using the energy spectrum of 22Na source. A magnetic field up to at least 30 Gauss can be eliminated by the proposed shielding. This satisfies the actual requirement of 8 Gauss. The dead time of the prototype detector was measured with a dedicated setup and measured to be 1.4 ns.

High quality AlAs1-xBix layers with Bi composition of 3%-10.5% have been successfully grown by molecular beam epitaxy. The Bi incorporation is confirmed by Rutherford backscattering spectroscopy. For a 400 nm thick AlAsBi layer, the strain relaxation occurs when the Bi composition is larger than 6.5%. Flux ratio is calculated from Knudsen-cell model and Maxwell equation, according to the geometrical relationship of our equipment. The Bi incorporation increases with increasing the As-Al flux ratio as well as the Bi flux. The extrapolation lattice constant of hypothetic zincblende AlBi alloy is about 6.23 angstrom.

We theoretically prepare a kind of two-mode entangled non-Gaussian state generated by combining quantum catalysis and parametric-down amplifier operated on the two-mode squeezing vacuum state. We then investigate the entanglement properties by examining Von Neumann entropy, EPR correlation, squeezing effect and the fidelity of teleportation. It is shown that only Von Neumann entropy can be enhanced by both single- and two-mode catalysis in a small squeezing region, while the other properties can be enhanced only by two-mode catalysis including symmetrical and asymmetrical cases. A comparison among these properties shows that the squeezing and the EPR correlation definitely lead to the improvement of both the entanglement and the fidelity, and the region of enhanced fidelity can be seen as a sub-region of the enhanced entanglement which indicates that the entanglement is not always beneficial for the fidelity. In addition, the effect of photon-loss after catalysis on the fidelity is considered and the symmetrical two-photon catalysis may present better behavior than the symmetrical single-photon case against the decoherence in a certain region.

Due to the random fluctuations in wind power, large amounts of grid integration will have a negative impact on grid operation and the consumers. The joint operation with pumped-storage hydroplant with good peak shaving performance can effectively reduce the negative impact on the safety and economic operation of power grid, and improve the utilization of wind power. In addition, joint operation can achieve the optimization of green power and improve the comprehensive economic benefits. Actually, the rational profit distribution of joint operation is the premise of sustainable and stable cooperation. This paper focuses on the profit distribution of joint operation, and applies improved shapely value method, which taking the investments and the contributions of each participant in the cooperation into account, to determine the profit distribution. Moreover, the distribution scheme can provide an effective reference for the actual joint operation of wind farm and pumped-storage hydroplant.