Separation method for multi-source blended seismic data

Multi-source seismic technology is an efficient seismic acquisition method that requires a group of blended seismic data to be separated into single-source seismic data for subsequent processing. The separation of blended seismic data is a linear inverse problem. According to the relationship between the shooting number and the simultaneous source number of the acquisition system, this separation of blended seismic data is divided into an easily determined or overdetermined linear inverse problem and an underdetermined linear inverse problem that is difficult to solve. For the latter, this paper presents an optimization method that imposes the sparsity constraint on wavefields to construct the object function of inversion, and the problem is solved by using the iterative thresholding method. For the most extremely underdetermined separation problem with single-shooting and multiple sources, this paper presents a method of pseudo-deblending with random noise filtering. In this method, approximate common shot gathers are received through the pseudo-deblending process, and the random noises that appear when the approximate common shot gathers are sorted into common receiver gathers are eliminated through filtering methods. The separation methods proposed in this paper are applied to three types of numerical simulation data, including pure data without noise, data with random noise, and data with linear regular noise to obtain satisfactory results. The noise suppression effects of these methods are sufficient, particularly with single-shooting blended seismic data, which verifies the effectiveness of the proposed methods.

Analysis of flow separation control using nanosecond-pulse discharge plasma actuators on a flying wing

Dielectric barrier discharge （DBD） plasma is one of most promising flow control method for its several advantages. The present work investigates the control authority of nanosecond pulse DBD plasma actuators on a flying wing model＇s aerodynamic characteristics. The aerodynamic forces and moments are studied by means of experiment and numerical simulation. The numerical simulation results are in good agreement with experiment results. Both results indicate that the NS-DBD plasma actuators have negligible effect on aerodynamic forces and moment at the angles of attack smaller than 16-. However, significant changes can be achieved with actuation when the model＇s angle of attack is larger than 16° where the flow separation occurs. The spatial flow field structure results from numerical simulation suggest that the volumetric heat produced by NS-DBD plasma actuator changes the local temperature and density and induces several vortex structures, which strengthen the mixing of the shear layer with the main flow and delay separation or even reattach the separated flow.

Experimental Investigation of Flow Separation Control Using Dielectric Barrier Discharge Plasma Actuators

Influence of plasma actuators as a flow separation control device was investigated experimentally. Hump model was used to demonstrate the effect of plasma actuators on external flow separation, while for internal flow separation a set of compressor cascade was adopted. In order to investigate the modification of the flow structure by the plasma actuator, the flow field was examined non-intrusively by particle image velocimetry measurements in the hump model experiment and by a hot film probe in the compressor cascade experiment. The results showed that the plasma actuator could be effective in controlling the flow separation both over the hump and in the compressor cascade when the incoming velocity was low. As the incoming velocity increased, the plasma actuator was less effective. It is urgent to enhance the intensity of the plasma actuator for its better application. Methods to increase the intensity of plasma actuator were also studied.

Wind tunnel experiments on flow separation control of an Unmanned Air Vehicle by nanosecond discharge plasma aerodynamic actuation

Plasma flow control（PFC） is a new kind of active flow control technology, which can improve the aerodynamic performances of aircrafts remarkably. The flow separation control of an unmanned air vehicle（UAV） by nanosecond discharge plasma aerodynamic actuation（NDPAA） is investigated experimentally in this paper. Experimental results show that the applied voltages for both the nanosecond discharge and the millisecond discharge are nearly the same, but the current for nanosecond discharge（30 A） is much bigger than that for millisecond discharge（0.1 A）. The flow field induced by the NDPAA is similar to a shock wave upward, and has a maximal velocity of less than 0.5 m/s. Fast heating effect for nanosecond discharge induces shock waves in the quiescent air. The lasting time of the shock waves is about 80 μs and its spread velocity is nearly 380 m/s. By using the NDPAA, the flow separation on the suction side of the UAV can be totally suppressed and the critical stall angle of attack increases from 20° to 27° with a maximal lift coefficient increment of 11.24%. The flow separation can be suppressed when the discharge voltage is larger than the threshold value, and the optimum operation frequency for the NDPAA is the one which makes the Strouhal number equal one. The NDPAA is more effective than the millisecond discharge plasma aerodynamic actuation（MDPAA） in boundary layer flow control. The main mechanism for nanosecond discharge is shock effect. Shock effect is more effective in flow control than momentum effect in high speed flow control.

A new gravity ＆ flotation separator with double-tailing discharge and its beneficiation performance

Introduced a new gravity and flotation separator with double-tailing dtsctaarge tor nne coat~, u,u ,,,~,.~ cation and cyclone scavenging with flotation in an original way. The beneficiation performance of it was good. The results show that the gravity and flotation separator with double-tailing discharge can produce high-quality clean coal of 10.46% ash from free coal of 35.56% ash. It can discharge the fine and coarse tailings separately.

Flow separation control over an airfoil using continuous alternating current plasma actuator

The flow separation control over an NACA 0015 airfoil using continuous alternating current(AC)dielectric barrier discharge(DBD)plasma actuator is investigated experimentally and numerically.This work is intended to report some observations made from our experiment,to which little attention is paid in the previous studies,but which is thought to be important to the understanding of control of complex flow separation with AC DBD.To this end,the response of separated flow to AC plasma actuation is visualized through the time-resolved particle image velocimetry(PIV)measurement,whereas numerical simulation is carried out to complement the experiment.The flow control process at chord-based Reynolds number(Re)of 3.31×105 is investigated.It is found that the response of external flow to plasma forcing is delayed for up to tens of milliseconds and the delay time increases with angle of attack increasing.Also observed is that at the intermediate angle of attack near stall,the forced flow features a well re-organized flow pattern.However,for airfoil at high post-stall angle of attack,the already well suppressed flow field can recover to the massively separated flow state and then reattach to airfoil surface with the flow pattern fluctuating between the two states in an irregular manner.This is contrary to one’s first thought that the forced flow at any angles of attack will become well organized and regular,and reflects the complexity of flow separation control.

Control of flow separation over a wing model with plasma synthetic jets

An array of 30 plasma synthetic jet actuators(PSJAs)is deployed using a modified multichannel discharge circuit to suppress the flow separation over a straight-wing model.The lift and drag of the wing model are measured by a force balance,and the velocity fields over the suction surface are captured by a particle imaging velocimetry system.Results show that the flow separation of the straight wing originates from the middle of the model and expands towards the wingtips as the angle of attack increases.The flow separation can be suppressed effectively by the PSJAs array.The best flow control effect is achieved at a dimensionless discharge frequency of F^+=1,with the peak lift coefficient increased by 10.5%and the stall angle postponed by 2°.To further optimize the power consumption of the PSJAs,the influence of the density of PSJAs on the flow control effect is investigated.A threshold of the density exits(with the spanwise spacing of PSJAs being 0.2 times of the chord length in the current research),below which the flow control effect starts to deteriorate remarkably.In addition,for comparison purposes,a dielectric barrier discharge(DBD)plasma actuator is installed at the same location of the PSJAs.At the same power consumption,4.9%increase of the peak lift coefficient is achieved by DBD,while that achieved by PSJAs reaches 5.6%.

Study on Intermittent Discharge Characteristics of Typical Solid Insulation Defects in Gas Insulated Switchgear

In response to the problem of frequent leakage and false alarm of partial discharge insulation defects in GIS,this paper conducts experimental research on intermittent discharge characteristics of common solid insulation defects in GIS.Using true GIS to build amulti-source testing platform for intermittent discharge of solid insulation defects,and using pulse current method,ultra-high frequency method,ultrasonic method,and gas characteristic component detectionmethod to study the variation law of intermittent discharge characteristics of solid insulation defects.The results showthat:the intermittent discharge state of metal fouling defects on the solid insulation surface decreases with the extension of the discharge time,the discharge time interval as a whole shows an increasing trend,and the metal fouling defects on the solid insulation surface in the intermittent discharge state is difficult to develop into a breakdown discharge fault.The overall discharge amount of air gap defects inside solid insulation also shows the law of increasing first and then decreasing,and the discharge amount of air gap defects inside solid insulation stays at a large level for a long time during intermittent discharge,and there is a risk of breakdown,and the discharge will gradually evolve into continuous discharge;ultrasonic method and characteristic component detection method cannot realize the effective perception of intermittent discharge of metal fouling.The 50-period mapping information commonly used in the power field cannot reflect the intermittent discharge variation law of solid insulation,and the 200-period UHF mapping composed of four groups of 50-period UHF mapping data can initially derive the intermittent discharge distribution law of solid insulation defects.The research results of this paper are of great significance to expand the knowledge of intermittent discharge characteristics and the detection of GIS discharge defects in the field.

A model of flow separation controlled by dielectric barrier discharge

Flow separation, as an aerodynamic phenomenon, occurs in specific conditions. The conditions are studied in a wind tunnel on different airfoils. The phenomenon can be delayed or suppressed by exerting an external momentum to the flow. Dielectric barrier discharge actuators arranged in a row of 8 and perpendicular to the flow direction can delay flow separation by exerting the momentum. In this study, a mathematical model is developed to predict a parameter, which is utilized to represent flow separation on an NACA0012 airfoil. The model is based on the neurofuzzy method applied to experimental datasets. The neuro model is trained in different flow conditions and the parameter is measured by pressure sensors.

A model for Nanosecond Pulsed Dielectric Barrier Discharge(NSDBD)actuator and its investigation on the mechanisms of separation control over an airfoil

In order to simulate the flow control problem by using Nanosecond Pulsed Dielectric Barrier Discharge(NSDBD),a one-zone inhomogeneous phenomenological model is constructed based on the experimental and theoretical results.The model is coupled with the unsteady Navier-Stokes equations,which can well predict the compression-expansion wave structures and wave speed compared with experimental results and can be applied to the simulation of the flow control by using NSDBD.The model is adopted to investigate the separation control over NACA0015 airfoil using the NSDBD plasma actuator.The separation-control mechanisms are revealed that the spanwise vortices produced by the plasma actuation play the key role.Each plasma actuation can produce a spanwise vortex around the separation point near the leading edge.The spanwise vortices make the separated free-shear layer unstable and shed away,move downstream along the upper wall,control the flow near the wall,and bring outer flow with high kinetic energy into the near wall region to realize the effective separation control over the upper surface of the airfoil.

Separator coatings as efficient physical and chemical hosts of polysulfides for high-sulfur-loaded rechargeable lithium–sulfur batteries

Lithium-sulfur batteries(LSBs)are promising alternative energy storage devices to the commercial lithium-ion batteries.However,the LSBs have several limitations including the low electronic conductivity of sulfur(5×10^-30S cm^-1),associated lithium polysulfides(PSs),and their migration from the cathode to the anode.In this study,a separator coated with a Ketjen black(KB)/Nafion composite was used in an LSB with a sulfur loading up to 7.88 mg cm^-2to mitigate the PS migration.A minimum specific capacity(Cs)loss of 0.06%was obtained at 0.2 C-rate at a high sulfur loading of 4.39 mg cm^-2.Furthermore,an initial areal capacity up to 6.70 mAh cm^-2 was obtained at a sulfur loading of 7.88 mg cm^-2.The low Cs loss and high areal capacity associated with the high sulfur loading are attributed to the large surface area of the KB and sulfonate group(SO3^-)of Nafion,respectively,which could physically and chemically trap the PSs.

基于“三焦生精”理论治疗成人原发免疫性血小板减少症

原发免疫性血小板减少症是一种免疫介导的以血小板减少为主要特征的疾病,归属于中医“紫癜病”范畴,临床多从火热亢盛、气虚失摄、脾不统血、肾虚火旺等方面论治。三焦理论始于《黄帝内经》,三焦具有通行原气,运化水液两大基本功能,该文首先对“三焦生精”的理论内涵进行阐述,其次基于“三焦生精”理论探讨原发免疫性血小板减少症的病机及治法,最后通过对一则验案进一步分析,以期为临床治疗原发免疫性血小板减少症拓宽思路。

对ZYFM型油水分离器存在缺陷的分析和改进

分析了ZYFM型油水分离器的工作原理和自动控制原理,发现该型油水分离器设计上有缺陷,导致船员故意排放超标污油水。通过改进控制线路和换装气开式三通阀,消除了设计上的缺陷,彻底杜绝了船员恶意排放超标污油水的现象。该方法具有思路新、成本低、操作简单和就地取材的特点,实际应用效果显著,具有良好的市场推广前景。

预焙阳极超细残分离技术研究与应用

残极长期与电解质接触,含有较高的电解质成分,如铝、钠、钾、钙、镁、锂、氟等成分,残极经过破碎、筛分,分成不同的粒度,在阳极炭块或阳极糊生产配料时,作为一种骨料加入。残极可分为两类:硬残极和软残极。软残极即是质量差的阳极,外部和内部被严重氧化所致,机械强度低,极易被碎成细末,细残极中钠、钙、铁元素含量极高,对阳极和原铝质量影响较大。再次循环利用前需予以排除。本文就超细残外排技术进行了研究和应用,实施后完全满足电解生产需求。

基于多端脉冲幅值比的变压器局部放电信号聚类分离方法

对电力变压器进行局部放电试验与检测时,多源脉冲混叠严重影响着局部放电信号的识别。本文提出一种基于多端脉冲幅值比的局放信号聚类分离方法。首先,开展220 kV变压器局放试验,对不同试验电压下PRPD、T-F谱图中存在的脉冲混叠现象进行分析;然后,基于不同类型脉冲在变压器中的传播衰减规律,提出了基于变压器多端检测的三维幅值比脉冲聚类分离方法,并结合DBSCAN算法实现该方法;最后,在220 kV变压器局放试验过程中开展了多端检测,并对脉冲进行聚类分离与来源分析。结果表明:利用多端脉冲幅值比聚类分离方法能够将局放试验过程中的多源混叠脉冲准确分为干扰脉冲以及两类放电脉冲,并且可以根据幅值比实现脉冲源的初步定位。多端脉冲幅值比聚类分离方法实现了变压器局放脉冲的提取,其发展和应用将有利于提升变压器局部放电检测中的抗干扰水平和检测准确度。

膜分离技术在工业废水零排放工艺中的应用研究

为应对我国工业快速发展带来的水资源短缺问题,废水零排放工艺成为废水处理领域关注的热点,膜分离技术以优越的分离、纯化等性能在诸多领域得到了广泛的应用。介绍并总结了膜分离技术的原理、分类及发展现状,重点探讨其在废水零排放工艺中的研究进展与工程应用实例,最后对膜分离技术在废水零排放工艺中的发展进行了展望。

低功率平板型霍尔推力器等离子体束流加速机制研究

为揭示平板型霍尔推力器的束流加速机理,并以此为基础提供推力器的性能优化方法,本文采用法拉第探针、E×B探针及推力架实验系统研究了平板型霍尔推力器在不同工况下的束流特性及推力器性能参数变化规律,并利用粒子网格法仿真获得了微观等离子体放电特征参数分布规律。研究表明,平板型霍尔推力器束流呈现出特有的“山”字形形貌,束流发散半角在所测量流量下约为70°,且随流量增大而增大,而电离加速区域分离的过程导致束流离子能量随流量增大先增大后减小。性能测试结果显示,平板型霍尔推力器随流量增大多价电离显著,电压利用率和工质利用率的提高平衡了电流利用率和束流发散效率的降低,使得其比冲和阳极效率随流量增大而提高。

煤化工废水热法分盐结晶工艺工程实例

针对某煤化工企业的上游中水回用装置所产生的高盐、高COD废水,采用热法分盐结晶工艺,实现了废水零排放与结晶盐资源化利用的目的。介绍了该处理工艺的流程及设计参数,给出了处理效果及运行成本。实际运行结果表明,产水完全符合回用要求,硫酸钠结晶盐平均纯度达99.09%,氯化钠结晶盐平均纯度达98.52%。该装置的连续稳定运行标志着热法分盐技术在煤化工废水处理领域得到了成功应用。

基于主动式频谱感知的高压电柜局部放电在线监测系统

为了准确监测高压电柜局部放电现象,避免高压电柜故障及电力系统失稳风险的发生,研究基于主动式频谱感知的高压电柜局部放电在线监测系统。系统包含主动式频谱感知单元、采集与存储单元、DSP控制处理单元及后台监测软件单元。通过主动式频谱感知单元接收高压电柜放电时产生的各类电磁波信号,对此类信号实施放大、分离、滤波及频谱空穴判别等处理,提取局部放电信号;经多信道传输此信号到采集与存储单元实施模拟信号采集与存储,运用DSP控制处理单元对所存储的模拟信号实施运算,获取放电脉冲量与数字信号;将数字信号输送到后台监测软件单元分析局部放电位置及类别,完成对高压电柜局部放电的在线监测。结果表明,所提系统具有理想的监测效果,可准确监测不同类别与不同频段的局部放电信号,在实际应用中可监测出局部放电量最高的高压电柜,有效规避高压电柜产生故障风险,保障电力系统的安全稳定运行。

磁混凝工艺处理燃煤电厂脱硫废水应用研究

采用磁混凝技术对燃煤电厂脱硫废水开展实验室和中试实验研究。通过实验室研究优化了磁混凝工艺的药剂投加量等工艺参数;在实验室数据的基础上,通过中试实验验证了磁混凝技术处理燃煤电厂脱硫废水的可行性并评价了该技术的经济性优势。