Real-Time Dwell Scheduling Based on a Unified Pulse Interleaving Framework for Phased Array Radar

Dwell scheduling is a key for phased array radar to realize multi-function and it becomes especially challenging in complex tactical situations.In this manuscript,a real-time radar dwell scheduling algorithm based on a unified pulse interleaving framework is proposed.A unified pulse interleaving framework that can realize pulse interleaving analysis for phased array radars with different receiving modes is put forward,which greatly improves the time utilization of the system.Based on above framework,a real-time two-stage approach is proposed to solve the optimization problem of dwell scheduling.The importance and urgency criteria are guaranteed by the first pre-schedule stage,and the desired execution time criterion is improved at the second stage with the modified particle swarm optimization(PSO).Simulation results demonstrate that the proposed algorithm has better comprehensive scheduling performance than up-to-date algorithms that consider the pulse interleaving technique for both single beam and multiple beams receiving modes.Besides,the proposed algorithm can realize dwell scheduling in realtime.

Current optimization-based control of dual three-phase PMSM for low-frequency temperature swing reduction

In this paper,a control scheme based on current optimization is proposed for dual three-phase permanent-magnet synchronous motor(DTP-PMSM)drive to reduce the low-frequency temperature swing.The reduction of temperature swing can be equivalent to reducing maximum instantaneous phase copper loss in this paper.First,a two-level optimization aiming at minimizing maximum instantaneous phase copper loss at each electrical angle is proposed.Then,the optimization is transformed to a singlelevel optimization by introducing the auxiliary variable for easy solving.Considering that singleobjective optimization trades a great total copper loss for a small reduction of maximum phase copper loss,the optimization considering both instantaneous total copper loss and maximum phase copper loss is proposed,which has the same performance of temperature swing reduction but with lower total loss.In this way,the proposed control scheme can reduce maximum junction temperature by 11%.Both simulation and experimental results are presented to prove the effectiveness and superiority of the proposed control scheme for low-frequency temperature swing reduction.

Deciphering engineering principle of three-phase interface for advanced gas-involved electrochemical reactions

As an alternative to conventional energy conversion and storage reactions,gas-involved electrochemical reactions,including the carbon dioxide reduction reaction(CO_(2)RR),nitrogen reduction reaction(NRR)and hydrogen evolution reaction(HER),have become an emerging research direction and have gained increasing attention due to their advantages of environmental friendliness and sustainability.Various studies have been designed to accelerate sluggish kinetics but with limited results.Most of them promote the reaction by modulating the intrinsic properties of the catalyst,ignoring the synergistic effect of the reaction as a whole.Due to the introduction of gas,traditional liquid-solid two-phase reactions are no longer applicable to future research.Since gas-involved electrochemical reactions mostly occur at the junctions of gaseous reactants,liquid electrolytes and solid catalysts,the focus of future research on reaction kinetics should gradually shift to three-phase reaction interfaces.In this review,we briefly introduce the formation and constraints of the three-phase interface and propose three criteria to judge its merit,namely,the active site,mass diffusion and electron mass transfer.Subsequently,a series of modulation methods and relevant works are discussed in detail from the three improvement directions of‘exposing more active sites,promoting mass diffusion and accelerating electron transfer’.Definitively,we provide farsighted insights into the understanding and research of three-phase interfaces in the future and point out the possible development direction of future regulatory methods,hoping that this review can broaden the future applications of the three-phase interface,including but not limited to gas-involved electrochemical reactions.

Electrical characteristics of new three-phase traction power supply system for rail transit

A novel three-phase traction power supply system is proposed to eliminate the adverse effects caused by electric phase separation in catenary and accomplish a unifying manner of traction power supply for rail transit.With the application of two-stage three-phase continuous power supply structure,the electrical characteristics exhibit new features differing from the existing traction system.In this work,the principle for voltage levels determining two-stage network is dissected in accordance with the requirements of traction network and electric locomotive.The equivalent model of three-phase traction system is built for deducing the formula of current distribution and voltage losses.Based on the chain network model of the traction network,a simulation model is established to analyze the electrical characteristics such as traction current distribution,voltage losses,system equivalent impedance,voltage distribution,voltage unbalance and regenerative energy utilization.In a few words,quite a lot traction current of about 99%is undertaken by long-section cable network.The proportion of system voltage losses is small attributed to the two-stage three-phase power supply structure,and the voltage unbal-ance caused by impedance asymmetry of traction network is less than 1‰.In addition,the utilization rate of regenerative energy for locomotive achieves a significant promotion of over 97%.

Speed Regulation Method Using Genetic Algorithm for Dual Three-phase Permanent Magnet Synchronous Motors

Dual three-phase Permanent Magnet Synchronous Motor(DTP-PMSM)is a nonlinear,strongly coupled,high-order multivariable system.In today’s application scenarios,it is difficult for traditional PI controllers to meet the requirements of fast response,high accuracy and good robustness.In order to improve the performance of DTP-PMSM speed regulation system,a control strategy of PI controller based on genetic algorithm is proposed.Firstly,the basic mathematical model of DTP-PMSM is established,and the PI parameters of DTP-PMSM speed regulation system are optimized by genetic algorithm,and the modeling and simulation experiments of DTP-PMSM control system are carried out by MATLAB/SIMULINK.The simulation results show that,compared with the traditional PI control,the proposed algorithm significantly improves the performance of the control system,and the speed output overshoot of the GA-PI speed control system is smaller.The anti-interference ability is stronger,and the torque and double three-phase current output fluctuations are smaller.

Optimization of Control Loops and Operating Parameters for Three-Phase Separators Used in Oilfield Central Processing Facilities

In this study,the Stokes formula is used to analyze the separation effect of three-phase separators used in a Oilfield Central Processing Facility.The considered main influencing factors include(but are not limited to)the typical size of oil and water droplets,the residence time and temperature of fluid and the dosage of demulsifier.Using the“Specification for Oil and Gas Separators”as a basis,the control loops and operating parameters of each separator are optimized Considering the Halfaya Oilfield as a testbed,it is shown that the proposed approach can lead to good results in the production stage.

Purification of Moringa oleifera Leaves Protease by Three-Phase Partitioning and Investigation of Its Potential Antibacterial Activity

One of plant-based products for dental care is plant-based proteolytic enzymes which are principally proteases. In order not to damage the protein and bioactive content, an efficient method should be employed for their purifications. As such, three-phase partitioning (TPP) was used to purify protease from moringa (Moringa oleifera). TPP is an emerging, promising, non-chromatographic and economical technology which is simple, quick, efficient and often one-step process for the separation and purification of bioactive molecules from natural sources. It involves the addition of salt (ammonium sulphate) to the crude extract followed by the addition of an organic solvent (butanol). The protein appears as an interfacial precipitate between upper organic solvent and lower aqueous phases. The various conditions such as ammonium sulphate, ratio of crude extract to t-butanol and pH which are required for attaining efficient purification of the protease fractions were optimized. Under optimized conditions, it was seen that, 35% of ammonium sulphate saturation with 1:0.75 ratio of crude extract to t-butanol at pH 7 gave 4.94-fold purification with 96.20% activity yield of protease in the middle phase of the TPP system. The purified enzyme from Moringa oleifera has no antimicrobial effect on the pathogenic bacteria tested. However, this purified enzyme, can be considered as a promising agent, cheap, and safe source which is suitable for using in various industries.

Vibration characteristics of sandwich plates with an auxetic honeycomb core and laminated three-phase skin layers under blast load

In this article,vibration characteristics of sandwich plates with an auxetic honeycomb core and laminated three-phase skin layers subjected to blast load are studied.Higher-order ES-MITC3 element based on higher-order shear deformation theory(HSDT)to achieve the governing equations.The sandwich plates with the ultra-light feature of the auxetic honeycomb core layer(negative Poisson’s ratio)and reinforced by two laminated three-phase skin layers.The obtained results in our work are compared with other previously published to confirm accuracy and reliability.In addition,the effects of parameters such as geometrical and material parameters on the vibration characteristics of sandwich plates with an auxetic honeycomb core and laminated three-phase skin layers are fully investigated.

Enhancing ammonia production rates from electrochemical nitrogen reduction by engineering three-phase boundary with phosphorus-activated Cu catalysts

Electrochemical N_(2) reduction reaction(eNRR) over Cu-based catalysts suffers from an intrinsically low activity of Cu for activation of stable N_(2) molecules and the limited supply of N_(2) to the catalyst due to its low solubility in aqueous electrolytes.Herein,we propose phosphorus-activated Cu electrocatalysts to generate electron-deficient Cu sites on the catalyst surface to promote the adsorption of N_(2) molecules.The eNRR system is further modified using a gas diffusion electrode(GDE) coated with polytetrafluoroethylene(PTFE) to form an effective three-phase boundary of liquid water-gas N_(2)-solid catalyst to facilitate easy access of N_(2) to the catalytic sites.As a result,the new catalyst in the flow-type cell records a Faradaic efficiency of 13.15% and an NH_(3) production rate of 7.69 μg h^(-1) cm^(-2) at-0.2 V_(RHE),which represent 3.56 and 59.2 times increases from those obtained with a pristine Cu electrode in a typical electrolytic cell.This work represents a successful demonstration of dual modification strategies;catalyst modification and N_(2) supplying system engineering,and the results would provide a useful platform for further developments of electrocatalysts and reaction systems.

Automatic measurement of three-phase contact angles in pore throats based on digital images

With the help of digital image processing technology, an automatic measurement method for the three-phase contact angles in the pore throats of the microfluidic model was established using the microfluidic water flooding experiment videos as the data source. The results of the new method were verified through comparing with the manual measurement data.On this basis, the dynamic changes of the three-phase contact angles under flow conditions were clarified by the contact angles probability density curve and mean value change curve. The results show that, for water-wetting rocks, the mean value of the contact angles is acute angle during the early stage of the water flooding process, and it increases with the displacement time and becomes obtuse angle in the middle-late stage of displacement as the dominant force of oil phase gradually changes from viscous force to capillary force. The droplet flow in the remaining oil occurs in the central part of the pore throats, without three-phase contact angle. The contact angles for the porous flow and the columnar flow change slightly during the displacement and present as obtuse angles in view of mean values, which makes the remaining oil poorly movable and thus hard to be recovered. The mean value of the contact angle for the cluster flow tends to increase in the flooding process, which makes the remaining oil more difficult to be recovered. The contact angles for the membrane flow are mainly obtuse angles and reach the highest mean value in the late stage of displacement, which makes the remaining oil most difficult to be recovered. After displacement, the remaining oils under different flow regimes are just subjected to capillary force, with obtuse contact angles, and the wettability of the pore throat walls in the microfluidic model tends to be oil-wet under the action of crude oil.

Application of CD34 expression combined with three-phase dynamic contrast-enhanced computed tomography scanning in preoperative staging of gastric cancer

BACKGROUND Accurate preoperative staging of gastric cancer(GC),a common malignant tumor worldwide,is critical for appropriate treatment plans and prognosis.Dynamic three-phase enhanced computed tomography(CT)scanning for preoperative staging of GC has limitations in evaluating tumor angiogenesis.CD34,a marker on vascular endothelial cell surfaces,is promising in evaluating tumor angiogenesis.We explored the value of their combination for preoperative staging of GC to improve the efficacy and prognosis of patients with GC.Medical records of 106 patients with GC treated at the First People's Hospital of Lianyungang between February 2021 and January 2023 were retrospectively studied.All patients underwent three-phase dynamic contrast-enhanced CT scanning before surgery,and CD34 was detected in gastroscopic biopsy specimens.Using surgical and pathological results as the gold standard,the diagnostic results of three-phase dynamic contrast-enhanced CT scanning at different T and N stages were analyzed,and the expression of CD34-marked microvessel density(MVD)at different T and N stages was determined.The specificity and sensitivity of three-phase dynamic contrast-enhanced CT and CD34 in T and N staging were calculated;those of the combined diagnosis of the two were evaluated in parallel.Independent factors affecting lymph node metastasis were analyzed using multiple logistic regression.RESULTS The accuracy of three-phase dynamic contrast-enhanced CT scanning in diagnosing stages T1,T2,T3 and T4 were 68.00%,75.00%,79.41%,and 73.68%,respectively,and for diagnosing stages N0,N1,N2,and N3 were 75.68%,74.07%,85.00%,and 77.27%,respectively.CD34-marked MVD expression increased with increasing T and N stages.Specificity and sensitivity of three-phase dynamic contrast-enhanced CT in T staging were 86.79%and 88.68%;for N staging,89.06%and 92.86%;for CD34 in T staging,64.15%and 88.68%;and for CD34 in N staging,84.38%and 78.57%,respectively.Specificity and sensitivity of joint diagnosis in T staging were 55.68%and 98.72%,and N staging were 75.15%and 98.47%,respectively,with the area under the curve for diagnosis improving accordingly.According to multivariate analysis,a longer tumor diameter,higher pathological T stage,lower differ-entiation degree,and higher expression of CD34-marked MVD were independent risk factors for lymph node metastasis in patients with GC.CONCLUSION With high accuracy in preoperatively determining the invasion depth and lymph node metastasis of GC,CD34 expression and three-phase dynamic contrast-enhanced CT can provide a reliable basis for surgical resection.

Spin-controlled generation of a complete polarization set with randomly-interleaved plasmonic metasurfaces

Optical metasurfaces,comprising subwavelength quasi-planar nanostructures,constitute a universal platform for manipulating the amplitude,phase,and polarization of light,thus paving a way for the next generation of highly integrated multifunctional optical devices.In this work,we introduce a reflective metasurface for the generation of a complete(angularly resolved)polarization set by randomly interleaving anisotropic plasmonic meta-atoms acting as nanoscale wave plates.In the proof-of-concept demonstration,we achieve multidirectional beam-steering into different polarization channels forming a complete set of polarization states,which can also be dynamically altered by switching the spin of incident light.The developed design concept represents a significant advancement in achieving flat polarization optics with advanced functionalities.

Analysis of rock physics response of gas-bearing volcanic reservoir based on three-phase poroelastic theory

Unlike previous theories with velocity and/or elastic modulus averaging, we use a three-phase porous rock physics model developed by Santos for analyzing the seismic response of two immiscible fluids in saturated porous media. Considering reservoir reference pressure and coupling drag of two fluids in pores, the effects of frequency, porosity, and gas saturation on the phase velocities of the P-and S-waves are discussed in detail under field conditions. The effects of porosity and gas saturation on Vp/Vs are also provided. The data for our numerical experiments are from a sample of deep volcanic rock from Daqing. The numerical results show that the frequency dispersion effect can be ignored for deep volcanic rocks with low porosity and low permeability. It is concluded that for deep volcanic rocks the effect of gas content in pores on Vp/Vs is negligible but the effect of porosity is significant when there is a certain amount of water contained in the pores. The accurate estimate of lithology and porosity in this case is relatively more important.

High-SpeedReal-TimeDataAcquisitionSystem Realized by Interleaving/Multiplexing Technique

The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improved the system conversion rata to 200?MHz and reduced the speed of data transporting and storing to 50?MHz. The high speed HDPLD and ECL logic parts were used to control system timing and the memory address. The multi layer print board and the shield were used to decrease interference produced by the high speed circuit. The system timing was designed carefully. The interleaving/multiplexing technique could improve the system conversion rata greatly while reducing the speed of external digital interfaces greatly. The design resolved the difficulties in high speed system effectively. The experiment proved the data acquisition system is stable and accurate.

空间光通信RS-INTERLEAVING信道编码研究

分析了空间激光通信的两种信道数学模型——自由空间光通信信道和大气激光通信信道,针对信道时变突发的特点,引入信道编码技术和交织技术,交织对发送信号进行扰码以克服大气信道相关性,Reed-Solomon(RS)线性分组码克服信道的突发错误,并进行一定程度的纠错。计算机仿真结果表明,RS编码和交织技术非常适合空间光通信信道,能大大降低系统的误码率。

COMPARISON AND EVALUATION OF CURRENT REFERENCE GENERATION STRATEGIES FOR ACTIVE POWER FILTERS IN THREE-PHASE FOUR-WIRE SYSTEMS

For three phase four-wire active power filters （APFs）, several typical power theories and corresponding current reference generation strategies are induced, p-q, d-q, unify power factor （UPF） and instantaneous active current （IAC） methods are analyzed and compared with each other. The interpretation of active and reactive currents in non-sinusoidal and unbalanced three-phase four-wire systems is given based on the generalized instantaneous reactive power theory. The performance and the characteristic are evaluated, and the application conditions of current reference generation strategies are concluded. Simulation results under different source voltages and loads verify the evaluation result.

Short-span interleaving based selected mapping

A novel interleaving based selected mapping （SLM） scheme to depress the relatively high peak power of transmit signals in multicarrier communications is proposed. In the scheme, a group of bit-level interleavers spanning only a few bits are used to produce multiple sequences representing the same information, and one of the sequences resulting in the lowest peak-to-average power ratio （PAPR） is selected for transmission. The implementation of the scheme including the structure of the short-span interleaver is illustrated. The performance of this PAPR reduction scheme is investigated by simulations. This scheme exhibits a good PAPR reduction performance, and for signals of high level modulation, such as 16QAM and 64QAM, it approaches the best performance of all SLM schemes. Compared to the conventional interleaving SLM, this short-span interleaving SLM results in a very short time delay, requires very few register units for buffering, and can be easily implemented by hardware.

THREE-PHASE BRIDGE INVERTER FOR 9kW DOUBLY SALIENT PERMANENT MAGNET MOTOR

The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet （DSPM） motor. Compared with common three-phase bridge inverters, the proposed inverter works under more complicated conditions with different principles for special winding back EMFs, position signals of hall sensors, and the given mode of switches. The ideal steady driving principles of the inverter for the motor are given. The working state with asymmetric winding back EMFs, inaccurate position signals of hall sensors, and the changing input voltage is analyzed. Finally, experimental results vertify that the given anal ysis is correct.

Novel radar dwell scheduling algorithm based on pulse interleaving

The problem of scheduling radar dwells in multifunction phased array radar systems is addressed. A novel dwell scheduling algorithm is proposed. The whole scheduling process is based on an online pulse interleaving technique. It takes the system timing and energy constraints into account. In order to adapt the dynamic task load, the algorithm considers both the priorities and deadlines of tasks. The simulation results demonstrate that compared with the conventional adaptive dwell scheduling algorithm, the proposed one can improve the task drop rate and system resource utility effectively.

大亚湾反应堆中微子实验Monte Carlo样本事例混合的interleaving算法

在反应堆中微子实验的物理数据分析中,前后事例间的时间关联分析是非常重要的一环.对事例间时间结构特性的研究,将有助于理解本底事例产生的物理机制,有利于对信号事例的挑选和对本底事例的排除.与此相应,在产生可用于物理分析的反应堆中微子Monte Carlo(MC)模拟数据的过程中,重构不同事例间的时间关联是一个重要步骤.通过研究大亚湾反应堆中微子实验的数据特点,开发了interleaving算法用于产生带有时间关联的海量物理数据;利用该方法实现了对不同样本的MC数据按事例率的混合;并简要给出了interleaving算法的空间和时间复杂度分析。