Typical Frequency Research Articles

Decreases in frequency-dependent intrinsic activity of the default mode network are associated with depression and cognition in patients with postacute sequelae of SARS-CoV-2 infection.

A significant proportion of patients who have recovered from COVID-19 suffer from persistent symptoms, referred to as "post-acute sequelae of SARS-CoV-2 infection (PASC)". Abnormal brain intrinsic activity has been observed in PASC patients, but the patterns of frequency-dependent intrinsic activity in the PASC and non-PASC (recovered COVID-19 patients without persistent symptoms) groups and their association with neuropsychiatric sequelae remain unclear in PASC. Twenty-nine PASC patients, 27 non-PASC subjects, and 31 healthy controls (HCs) were recruited. The voxel-level fractional amplitude of low-frequency fluctuation (fALFF) was calculated in different frequency bands (typical frequency band: 0.01-0.10Hz; slow 5: 0.01-0.023Hz; slow 4: 0.023-0.073Hz) to assess regional intrinsic activity patterns within different groups. Correlation analyses were performed to explore the associations between frequency-dependent alterations and clinical variables. Significant frequency-dependent alterations in intrinsic activity patterns were observed in both the PASC and non-PASC groups, primarily involving regions of the default mode network (DMN). The decreased fALFF values of the DMN in different frequency bands were associated with different symptoms in PASC. For example, decreased fALFF in the left precuneus in the typical frequency band was related to general attention impairment in PASC, whereas decreased fALFF in the left superior frontal gyrus appeared in non-PASC. The fALFF alterations in the left precuneus/posterior cingulate gyrus in the slow 5 band were also related to cognitive performance in PASC. Additionally, in the slow 4 band, decreased fALFF in the right angular gyrus was associated with depressive symptoms in the PASC. Our results may provide insights into the potential neural mechanisms underlying symptoms in PASC patients.

Type IV-like Solar Radio Burst Consisting of a Series of Short-time Bursts Observed by PSP

Abstract Solar and interplanetary radio bursts can reflect the existence and motion of energetic electrons and are therefore a kind of vital phenomenon in solar activities. The present study reported a solar radio storm observed by the Parker Solar Probe (PSP) in its eighth orbital encounter phase, and it lasted about 20 hr in a frequency range of 0.5–15 MHz, called the type IV-like burst. It consists of a series of numerous short-time (ST) bursts with the central frequency drifting slowly from ~5 to ~1 MHz, and each individual ST burst appears at a much faster frequency drifting rate and has a typical frequency range of a few MHz and a short duration of about 1–4 minutes. Based on the empirical models of the solar atmosphere adopted commonly, combining the in situ measurement by PSP, we analyzed and compared some possible mechanisms for the generation of these small-scale ST bursts and proposed that they were generated probably by a group of solitary kinetic Alfvén waves (SKAWs) in a magnetic loop accompanying coronal mass ejection and slowly moving outward, in which the frequency drifting of individual ST burst is caused by the SKAW's propagation and the central frequency drifting may be attributed to the motion of the magnetic loop.

Visible and near-infrared nanoscale spectroscopy with photo-induced force microscopy.

Photo-induced force microscopy (PiFM) uses laser modulation at the atomic force microscope cantilever's typical mechanical resonance frequency, to encode the material near-field response in the probes nanomechanics. While this technique offers the simplicity gained by mechanical detection, it can be challenging for hyperspectral measurements. Modulation in the visible and near-infrared ranges, often involves using acousto-optic modulators that introduce a wavelength-dependent laser steering, detrimental for spectroscopic purposes. Here, we introduce an innovative strategy, based on an electro-optic modulator (EOM), which eliminates the need for realignment, making PiFM a valuable tool for nanoscale spectroscopy in the visible and near-infrared spectra. We test the new EOM-based setup on a WSe2 sample where we visualize the propagation of polaritonic waveguide modes, which hybridize with the material exciton to form exciton-polaritons. Finally, we extend this EOM-based PiFM setup from standard amplitude-modulation PiFM to polarization-modulation PiFM, paving the way for investigations, at the nanoscale, of linear birefringence and dichroism in the visible and near-infrared ranges.

Exploring non-radial oscillation modes in dark matter admixed neutron stars

Because of their extreme densities and consequently, gravitational potential, compact objects such as neutron stars can prove to be excellent captors of dark matter particles. Considering purely gravitational interactions between dark and hadronic matter, we construct dark matter admixed stars composed of two-fluid matter subject to current astrophysical constraints on maximum mass and tidal deformability. We choose a wide range of parameters to construct the dark matter equation of state, and the DDME2 parameterization for the hadronic equation of state. We then examine the effect of dark matter on the stellar structure, tidal deformability and non-radial modes considering the relativistic Cowling approximation. We find the effect on p-modes is substantial, with frequencies decreasing up to the typical f-mode frequency range for most stars with a dark matter halo. The effects on the f-mode frequency are less extreme. Finally, we find the most probable values of the dark matter parameters that satisfy the observational constraints.

Global magnetic field properties in the solar wind interaction of Mercury from MESSENGER measurements

The space environment of Mercury is shaped by its proximity to the Sun and by the relatively weak planetary magnetic field, presenting a unique regime of plasmas and shock conditions. We present the global magnetic properties in Mercury's space environment based on more than 4 years of MESSENGER Magnetometer data. We used 20 Hz magnetic field data to examine the magnetic strength, the field configurations, and the fluctuations. We considered both compressional and transverse modes, with frequencies from 5 mHz to 10 Hz, which cover typical ultra-low frequency waves at Mercury. We identified regions of the solar wind, the magnetosheath, and the magnetosphere during over 4\,000 MESSENGER orbits. The solar wind and magnetosheath data were analysed in the solar wind interplanetary magnetic field (IMF) coordinate system, and the magnetosphere data were analysed in the aberrated Mercury solar magnetospheric coordinate system. Each data point was relocated into normalised space using averaged magnetopause and bow-shock models. The magnetic environments for a quasi-parallel and quasi-perpendicular IMF were compared. Under the typical Parker-spiral IMF, the magnetic environment of Mercury features strong fluctuations that are dominated by the transverse mode and stem from interactions at the bow shock and the magnetopause. When they are subjected to a quasi-perpendicular IMF, the magnetic fluctuations diminish, and the magnetic field strength becomes highly compressed throughout the bow shock, magnetosheath, and magnetosphere. Unlike Earth, Mercury exhibits weaker dawn-dusk asymmetries in magnetic field strength and lacks substantial magnetosheath-generated sources of magnetic fluctuations. The magnetic field draping pattern associated with the IMF cone angle at Mercury also differs from that at Earth. Our comparative analysis highlights the critical role of the solar wind Mach number, the radial IMF component, and the system scale size in shaping planetary space environments.

Safety of non-invasive brain stimulation in patients with implants: a computational risk assessment.

Non-invasive brain stimulation (NIBS) methodologies, such as transcranial electric (tES) are increasingly employed for therapeutic, diagnostic, or research purposes. The concurrent presence of active/passive implants can pose safety risks, affect the NIBS delivery, or generate confounding signals. A systematic investigation is required to understand the interaction mechanisms, quantify exposure, assess risks, and establish guidance for NIBS applications. We used measurements, simplified generic, and detailed anatomical modeling to: (i) systematically analyze exposure conditions with passive and active implants, considering local field enhancement, exposure dosimetry, tissue heating and neuromodulation, capacitive lead current injection, low-impedance pathways between electrode contacts, and insulation damage; (ii) identify risk metrics and efficient prediction strategies; (iii) quantify these metrics in relevant exposure cases and (iv) identify worst case conditions. Various aspects including implant design, positioning, scar tissue formation, anisotropy, and frequency were investigated. At typical tES frequencies, local enhancement of dosimetric exposure quantities can reach up to one order of magnitude for deep brain stimulation (DBS) and stereoelectroencephalography implants (more for elongated passive implants), potentially resulting in unwanted neuromodulation that can confound results but is still 2-3 orders of magnitude lower than active DBS. Under worst-case conditions, capacitive current injection in the active implants' lead can produce local exposures of similar magnitude as the passive field enhancement, while capacitive pathways between contacts are negligible. Above 10 kHz, applied current magnitudes increase, necessitating consideration of tissue heating. Furthermore, capacitive effects become more prominent, leading to current injection that can reach DBS-like levels. Adverse effects from abandoned/damaged leads in direct electrode vicinity cannot be excluded. Safety related concerns of tES application in the presence of implants are systematically identified and explored, resulting in specific and quantitative guidance and establishing basis for safety standards. Furthermore,several methods for reducing risks are suggested while acknowledging the limitations(see Sec. 4.5).

KIC 8840638: A Newly Discovered Eclipsing Binary with δ Scuti–Type Oscillations

In this paper, we analyze the light variation of KIC 8840638 using high-precision time-series data from the Kepler mission. The analysis reveals that this target is a new detached eclipsing binary system with a δ Scuti component, rather than a single δ Scuti star as previously known. The frequency analysis of short-cadence data reveals 95 significant frequencies, most of which lie in a frequency range of 23−32 day−1. Among them, seven independent frequencies are detected in the typical frequency range of δ Scuti stars, and they are identified as pressure modes. In addition, a possible large separation value of Δν = 36.5 ± 0.1 μHz is also detected with the Fourier transform (FT) and autocorrelation function (AC) analysis. The orbital frequency f orb (= 0.320008 day−1) and its harmonics are also detected directly in the frequency spectrum. The binary modelings derived from PHOEBE indicate that this binary system is in detached configurations with a mass ratio of q=0.33−0.04+0.06 , an inclination angle of 40.19−2.84+3.96 ​​​​​°. The derived parameters and binary evolutionary model suggest that the primary star is an object on the verge of leaving the main sequence with a temperature of ∼7600 K, while the secondary appears to be a cool component entering the giant branch with a temperature ∼3100 K lower than the primary. Moreover, this system may have undergone a mass ratio reversal, where the more massive star is the gainer component and the less massive one is the donor star.

Fatigue Assessment of Pier Structures Under Dynamic Forces

Pier structures in port and fishing harbor facilities require dynamic analyses during the design phase to account for external dynamic forces because of their high flexibility. Dynamic forces are frequently approximated as equivalent static forces for design purposes in practical engineering applications, but the fluctuational effects induced by these dynamic forces can be neglected. As the frequency range of wave forces acting on pier structures (0.05–1.0 Hz) significantly overlaps with the typical natural frequency range of pier structures (0.25–4.0 Hz), the response of a pier structure can be amplified because of the dynamic effects of the waves. In this study, we conducted a dynamic analysis by applying wave forces—a representative dynamic load—to a pier structure. The results were compared with those from a static analysis. A fatigue life assessment, which is often overlooked in static analyses, was also performed. The findings indicated that the concrete at the connection between the upper pier and steel piles exhibited a fatigue life of 27.3 years. The steel piles exhibited fatigue lives of 27.1 and 8.3 years depending on the weld details, falling short of the expected structural durability. Based on these results, recommendations for pier structures are proposed.

Primary prevention of venous thromboembolic complications in spinal cord injury: modern concepts

Venous thromboembolism is a common complication following spinal cord injury that can significantly aggravate a pre-existing condition and lead to a death. Patients who suffer acute spinal cord injury have a higher prevalence of venous thromboembolism than patients who suffer other traumatic injuries with sparing of the spinal cord. It is important for physical medicine and rehabilitation specialists to have knowledge аbout primary prevention of venous thromboembolism in patients with acute, subacute and chronic spinal cord injury. This article provides a brief overview of typical venous thromboembolism frequency (leg deep vein thrombosis and pulmonary embolism), pathogenesis peculiarities, venous thromboembolism risk factors and diagnostic considerations. The main attention is given to the primary thromboprophylaxis (methods and duration) depending on the spinal cord injury period and the spinal cord injury level. Further studies are required to clarify the optimal prophylaxis methods and protocols to prevent venous thromboembolism following spinal cord injury.

Reliable measurement of auditory-driven gamma synchrony with a single EEG electrode: A simultaneous EEG-MEG study

ObjectiveAuditory-driven gamma synchrony (GS) is linked to the function of a specific cortical circuit based on a parvalbumin+ and pyramidal neuron loop. This circuit is impaired in neuropsychiatric conditions (i.e. schizophrenia, Alzheimer's disease, stroke etc.) and its relevance in clinical practice is increasingly being recognized. Auditory stimulation at a typical gamma frequency of 40 Hz can be applied as a ‘stress test’ of excitation/inhibition (E/I) of the entire cerebral cortex, to drive GS and record it with magnetoencephalography (MEG) or high-density electroencephalography (EEG). However, these two techniques are costly and not widely available. Therefore, we assessed whether a single EEG electrode is sufficient to provide an accurate estimate of the auditory-driven GS level of the entire cortical surface while expecting the highest correspondence in the auditory and somatosensory cortices. MethodsWe measured simultaneous EEG-MEG in 29 healthy subjects, utilizing 3 EEG electrodes (C4, F4, O2) and a full MEG setup. Recordings were performed during binaural exposure to auditory gamma stimulation and during silence. We compared GS measurement of each of the three EEG electrodes separately against full MEG mapping. Time-resolved phase locking value (PLVt) was computed between EEG signals and cortex reconstructed MEG signals. ResultsDuring auditory stimulation, but not at rest, EEG captures a significant amount of GS, especially from both auditory cortices and motor-premotor regions. This was especially true for frontal (C4) and central electrodes (F4). Discussion and ConclusionsWhile hd-EEG and MEG are necessary for accurate spatial mapping of GS at rest and during auditory stimulation, a single EEG channel is sufficient to detect the global level of GS. These results have great translational potential for mapping GS in standard clinical settings.

Thin layer axion dynamo

We study interacting classical magnetic and pseudoscalar fields in frames of the axion electrodynamics. A large scale pseudoscalar field can be the coherent superposition of axions or axion like particles. We consider the evolution of these fields inside a spherical clump. Decomposing the magnetic field into the poloidal and toroidal components, we take into account their symmetry properties. Within a spherical clump, we use a thin layer approximation in the induction and Klein–Gordon equations, where the dependence of the fields on the latitude is accounted for. Then, we derive the dynamo equations in the low mode approximation. The nonlinear evolution equations for the harmonics of the magnetic and pseudoscalar fields are solved numerically. As an application, we consider a dense axion star embedded in solar plasma. The behavior of the harmonics and their typical oscillations frequencies are obtained. We suggest that such small size axionic objects, containing oscillating magnetic fields, can cause electromagnetic flashes, recently observed in the solar corona, contributing to the corona heating.

Identifying Three Psilocybin Use Patterns by Frequency and Quantity.

Patterns of psilocybin use in non-clinical settings are not well described in the literature. Psilocybin use can involve infrequent, large (i.e., macro) doses that produce hallucinogenic effects. In addition, some people report psilocybin use at particularly small (i.e., micro), sub-perceptual doses. Given the heterogeneity in reported use metrics, we sought to determine whether there are identifiable patterns of psilocybin use based on participants' self-described typical use frequencies and quantities and to describe how demographic characteristics are associated with each pattern of use. Participants were recruited from online communities via Reddit.com. We used Latent Profile Analysis to discern psilocybin use patterns defined by frequency and quantity of use. The analytic sample consisted of 664 participants (75.6% US residents; 83.1% white; 67.2% male). The Chipper Profile (18%) was associated with approximately 1-4 annual uses and using between 0.75g and 1.0g of dehydrated, psilocybin-containing mushrooms. The Tripper Profile (64%) was associated with approximately 2-6 annual uses and self-reported use quantities between 2-4g. The Microdoser Profile (18%) was related to substantively higher psilocybin use frequencies than the other profiles (between 2-4 times a week) and a lower range of preferred quantities (between 0.25g - 0.75g). Additionally, profiles differed by certain demographic measurements, lifetime psilocybin use, and timing of psilocybin use. Psilocybin use in non-clinical settings is heterogeneous. We identified three profiles that differed on frequency and quantity of use and their associated demographic characteristics. Next steps are to identify factors that affect one's likelihood of experiencing particular use outcomes and to explore use variability.

An investigation of the electrical dynamics in electroactive polymer transducers with resistive electrodes

To pursue a variable-capacitance working principle, transducers based on soft electroactive polymers (EAPs) need deformable electrodes that match the compliance and stretchability of the EAP polymeric substrates. A variety of manufacturing procedures are available to create conductive materials that can achieve this, including solutions that can provide remarkably low resistivity. However, the simplest and most feasible options often involve the use of particle-filled (e.g. carbon-filled) polymer composites, which, while easy to produce, tend to exhibit relatively high resistivity. This high level of resistivity, combined with the inherent capacitance of EAP transducers, introduces dynamic effects in the devices electrical activation, which may affect performance. This paper investigates the impact of electrode resistivity on the electrical dynamics of EAP devices, combining continuum models and experimental validations. We use a continuum generalisation of known resistive-capacitive (RC) transmission line models to accurately predict voltage gradients on the surfaces of electrostatic transducers subject to rapidly varying voltages. We then present an experimental validation by measuring the spatial voltage distributions over carbon-based polymeric electrodes of dielectric elastomer (DE) transducers, and find a good agreement with our model predictions. We use our validated model to provide general estimates of the typical charging time and limit working frequency ranges of DE devices as a function of their dimensional scale and electrode sheet resistance. Our model provides useful indications for designing compliant electrodes in EAP transducers given target performance, or to understand the working limits of devices with given geometry and dielectric-electrode properties.

Investigations on Target Strength Estimation Methods: A Case Study of Chub Mackerel (Scomber japonicus) in the Northwest Pacific Ocean

Target strength (TS) is an acoustic property of individual marine organisms and a critical factor in acoustic resource assessments. However, previous studies have primarily focused on measuring TS at narrowband, typical frequencies, which cannot meet the requirements of broadband acoustic technology research. Additionally, for marine fish, conducting in situ TS measurements is challenging due to environmental constraints. Rapidly freezing and preserving fish samples for transfer to the laboratory is a common method currently used. However, the impact of freezing preservation during transportation on the swimbladder morphology and TS of swimbladder-bearing fish remains unclear. This study investigated the differences in swimbladder morphology and TS of Chub mackerel (Scomber japonicus) before and after freezing. Then, we compared different TS measurement methods through ex situ TS measurements (45–90 kHz, 160–260 kHz) and the Kirchhoff-ray mode model (KRM) simulations (1–300 kHz) and studied the broadband scattering characteristics of Chub mackerel based on the KRM model. The results showed that the morphology of the swimbladder was reduced after freezing, with significant changes in swimbladder height and volume. However, the trends of TS were not consistent and the changes were small. The difference between the KRM model and ex situ measurements was −0.38 ± 1.84 dB, indicating good applicability of the KRM. Based on the KRM results, the TS exhibited significant directivity, with fluctuations gradually decreasing and stabilizing as frequency increased. In the broadband mode, the relationship between TS and body length (L) of Chub mackerel was TS = 20log(L) − 66.76 (30 > L/λ >10). This study could provide a reference for acoustic resource estimation and species identification of Chub mackerel in the Northwest Pacific Ocean.

Investigating Intra-Pulse Doppler Frequency Coupled in the Radar Echo Signal of a Plasma Sheath-Enveloped Target

In detecting hypersonic vehicles, the radar echo signal is coupled with an intra-pulse Doppler frequency (I-D frequency) component caused by relative motion of a plasma sheath (PSh) and the vehicle, which can induce the phenomenon of a ghost target in a one-dimensional range profile. In order to investigate the I-D frequency generated by the relative motion of a PSh, this study transforms a linear frequency modulated (LFM) signal into a single carrier frequency signal based on echo signal equivalent time delay-dechirp processing and realizes high resolution and fast extraction of the I-D frequency coupled with the frequency-domain echo signal. Furthermore, by relying on the computation of the surface flow field of the RAMC-II Blunt Cone Reentry Vehicle, the coupled I-D frequency in the radar echo signal of a PSh-enveloped target under circumstances of typical altitudes and carrier frequencies is extracted and further investigated, revealing the variation law of I-D frequency. The key findings of this study provide a novel approach for suppressing anomalies in radar detection of PSh-enveloped targets as well as effective detecting and as robust target tracking.

Radiofrequency Induction Heating for Green Chemicals Manufacture: A Systematic Model of Energy Losses and a Scale-Up Case-Study.

Radiofrequency (RF) induction heating has generated much interest for the abatement of carbon emissions from the chemicals sector as a direct electrification technology. Three challenges have held back its deployment at scale: reactors must be built from nonconductive materials which eliminates steel as a design choice; the viability of scale-up is uncertain; and to date the reported energy efficiency has been too low. This paper presents a model that for the first time makes a comprehensive analysis of energy losses that arise from RF induction heating. The maximum energy efficiency for radio frequency induction heating was previously reported to be 23% with a typical frequency range of 200-400 kHz. The results from the model show that an energy efficiency of 65-82% is achieved at a much lower frequency of 10 kHz and a reactor diameter of 0.2 m. Energy efficiency above 90% with reactor diameters above 1 m in diameter are predicted if higher voltage radio frequency sources can be developed. A new location of the work coil inside of the reactor wall is shown to be highly effective. Losses arising from heating a steel reactor wall in this configuration are shown to be insignificant, even when the wall is immediately adjacent to the work coil. This analysis demonstrates that RF induction heating can be a highly efficient and effective industrial technology for coupling high energy demand chemicals manufacture electricity from zero carbon renewables.

Range selective digital holographic imaging of vibrating objects using FMCW lidar

The use of frequency modulated continuous wave (FMCW) chirped transmit and reference waveforms in digital holographic (DH) imaging has enabled range selectivity. By frequency shifting the reference beam to compensate for the typical FMCW lidar beat frequency associated with a particular range, a temporally stable holographic image is formed for objects at the selected range and coherently integrates on a short wave infrared (SWIR) sensor. For vibrating objects, longitudinal movements of the object greater than half of an optical wavelength during the exposure time of the sensor array induce phase shifts that can wash out the hologram. An analog feedback system was designed and constructed whereby a lidar subassembly provides real time phase compensation information to a DH subassembly in order to stabilize the range selective digital holographic recording of the object. The design and characterization of the feedback system, as well as the results demonstrating the performance for vibrating objects that move over 17 wavelengths during the sensor exposure, are discussed.

Novel Frequency Regulation Scenarios Generation Method Serving for Battery Energy Storage System Participating in PJM Market

As one of the largest frequency regulation markets, the Pennsylvania-New Jersey-Maryland Interconnection (PJM) market allows extensive access of Battery Energy Storage Systems (BESSs). The designed signal regulation D (RegD) is friendly for use with BESSs with a fast ramp rate but limited energy. Designing operating strategies and optimizing the sizing of BESSs in this market are significantly influenced by the regulation signal. To represent the inherent randomness of the RegD signal and reduce the computational burden, typical frequency regulation scenarios with lower resolution are often generated. However, due to the rapid changes and energy neutrality of the RegD signal, generating accurate and representative scenarios presents challenges for the methods based on shape similarity. This paper proposes a novel probability-based method for generating typical regulation scenarios. The method relies on the joint probability distribution of two features with a 15-min resolution, extracted from the RegD signal with a 2 s resolution. The two features can effectively portray the characteristic of RegD signal and its influence on BESS operation. Multiple regulation scenarios are generated based on the joint probability distributions of these features at first, with the final typical scenarios chosen based on their probability distribution similarity to the actual distribution. Utilizing regulation data from the PJM market in 2020, this paper validates and analyzes the performance of the generated typical scenarios in comparison to existing methods, specifically K-means clustering and the forward scenarios reduction method.

Mode-locked waveguide polariton laser

So far, exciton-polariton (polariton) lasers were mostly single-mode lasers based on microcavities. Despite the large repulsive polariton-polariton interaction, a pulsed mode-locked polariton laser was never, to our knowledge, reported. Here, we use a 60-µm-long GaN-based waveguide surrounded by distributed Bragg reflectors forming a multi-mode horizontal cavity. We demonstrate experimentally and theoretically a polariton mode-locked micro-laser operating in the blue-UV, at room temperature, with a 300 GHz repetition rate and 100-fs-long pulses. The mode-locking is demonstrated by the compensation (linearization) of the mode dispersion by the self-phase modulation induced by the polariton-polariton interaction. It is also supported by the observation in experiment and theory of the typical envelope frequency profile of a bright soliton.

Influences of the vibration frequency and phase of the core of ultra-high voltage shunt reactors on suspended discharge in oil-paper insulation

Severe vibration of the core of ultra-high voltage (UHV) shunt reactors under operating conditions often leads to the occurrence of suspension electrode, and such a suspended discharge defect will destroy the oil-paper insulation. It is necessary to investigate the influence of vibration on suspended discharge when determining the best operating condition of UHV shunt reactors. The vibration frequency of the suspension electrode and the phase difference between the applied voltage and the vibration are studied by simulation and experiment. The simulation results show that the phase difference between the voltage and the vibration parameters will lead to an increase in the surface maximum field strength. The distortion of the field intensity caused by several typical vibration frequencies of reactor vibration is ranked (in ascending order) thus: 100, 300, 50, and 200 Hz. There is a coupling relationship between the phase difference and the vibration frequency on the suspended discharge, which will lead to an inconsistency between the field intensity and each single factor. The partial discharge test results of the collision between the suspension electrode and the high-voltage electrode show that the discharge generated by vibration at 100 Hz is much higher than that at other frequencies, followed by those at 300 and 50 Hz, and the discharge generated by vibration at 200 Hz is very small. When the phase difference of voltage advance vibration is between 0° and 90°, the quantity of local discharge is large. When the phase difference is between 90° and 180°, the local discharge is small.