Abstract Transformers are widely distributed and extremely important energy conversion equipment in the power system. However, high altitude electromagnetic pulse (HEMP) can induce a steep voltage with peak value of up to thousands kilovolts on overhead line, frequency is 100 MHz, which easy damage transformer seriously threaten safe stable operation Therefore, protect safety system, analysing wave process under action HEMP necessary. Accordingly, there need for an ultra‐wide band model...

Background & aims The immune checkpoint recently provides a new strategy for the immunotherapy of malignant tumors. However, role in microenvironment DLBCL is not completely clear. Methods We detected expression PD-1, LAG-3, TIM-3, and TIGIT on TILs tumor cells among 174 patients by IHC. Results In TILs, positive rates TIM-3 were 79.3%, 78.8%, 62.7% 69.5%, respectively.TIM-3 expressed 44.8% 45.4% cells. was significantly correlated with Ann-Arbor stage (P=0.039). There correlation...

Self-triggered pre-ionized switches with four-electrode structures are widely used in large pulsed power generators. Reducing its time delay jitter is an essential requirement. To understand the delay, this paper investigates breakdown processes and mechanisms. The switch divided into two symmetrical sub-gaps a sphere-plate structure. of nitrogen photographed by ICCD camera. It observed that can be separately spark discharge. Uniform discharge stimulated from main electrodes sub-gaps....

A novel hybrid nanostructure, that is a Ag nanoparticle decorated LaF3:Yb3+/Ln3+@SiO2 nanosphere (Ln=Er, Tm), was constructed by facile strategy, and characterized XRD, TEM, FTIR, XPS UV–vis–NIR absorption. Obvious spectral broadening red-shift on the surface plasmon resonance were obtained adjusting size configuration of nanoparticles. Effective upconversion luminescence enhancements for Er3+ Tm3+ containing samples obtained. It suggested enhancement results from both excitation emission...

In a wide variety of high-power pulsed devices, the megavolt switch plays key role in system performance. A capacitance-resistance coupling structure was designed to produce UV light which triggered decrease breakdown jitter. High-speed electrical measurements with circuit integrating probe nanosecond range were employed measure voltage before switch. From experimental results, characteristic 3-MV UV-illumination obtained 1.6-2.5 MV: The jitter is lower than 25 kV, and time shorter 5 ns.

Due to its low-loss and high dielectric strength, polypropylene is widely used as electrical insulation material in pulse capacitors. In order study breakdown characteristics for nanosecond voltage pulses, an experimental setup was designed generate pulses with a 10%-90% rise time of 38 ns full width at half maximum about 90 ns. Tests the three films thicknesses 12, 15, 18 μm were performed. addition, hundreds nanoseconds dc also applied comparison. The results reveal that most occurs during...

Optical properties of periodic nanorings with built-in V-shaped nanowedges (NRBV) are investigated theoretically. Tunable ultrahigh order Fano resonances achieved and they found to be sensitive geometric parameters surrounding dielectric environment the planar nanostructure. High can suppressed or enhanced by adjusting opening angle nanowedge, size nanoring aspect ratio nanowedge. Moreover, manipulating offset filling dielectrics asymmetrically revive when nanowedge develops into a straight...

In a wide variety of high-power pulsed devices, vacuum surface flashover plays key role in the system performance. High-speed electrical measurements with temporal resolution nanosecond range were employed to measure characteristics, and high-speed three-frame photography was used image channels at different phases along insulator surface. From these test results, under pulse would experience process three typical phases: initial phase, developing extinguishing phase. Spectra luminosity...

In a wide variety of high-power pulsed facilities, megavolt switches play key role in determining the system performance. particular, ultraviolet (UV)-illuminated have been widely used for their high-voltage, low-jitter characteristics. this paper, two factors that may affect breakdown jitter 3 MV UV-illuminated switch under voltages were investigated, namely, electric field enhancement factor UV-illuminating gap (UV gap) and number UV gaps. The experimental results show is important...

Self-assemblies fabricated from dendrimers and amphiphilic polymers have demonstrated remarkable performances a wide range of applications. Direct self-assembly hyperbranched into highly ordered macrostructures with heat-resistance remains big challenge due to the weak amphiphilicity polymers. Here, we report amido-ended polyester (HTDA-2) millimeter-size dendritic films using combined hydrogen bond interaction solvent induction. The process mechanism been studied. Hydrogen between groups...

In this paper, the effects of pulse voltage rise time on nanosecond pulsed breakdown nitrogen spark switch at atmospheric pressure are analyzed. Based assumption initial electrons generation due to field emission, simulations performed using a three-dimensional particle-in-cell, Monte Carlo-collision model for with 40, 60, and 100 ns, respectively. The experiments carried out three different times. results obtained as follows. First, includes formation fast propagation streamer, which depend...

The simulator is an indispensable device for the study of high-altitude electromagnetic pulse (HEMP) effects. In order to improve quality electric field waveforms HEMP simulator, we carried out simulation and experimental studies biconical-wire grid antenna. A new bicone-wire antenna was designed by using skeletonized cones instead solid cones, which can substantially mobility simulator. effects different aspect ratios cone structures on waveform distribution characteristics were analyzed....

The breakdown process of a self-triggered preionized switch with the four-electrode structure under nanosecond pulses is studied based on optical diagnosis. both subgaps initiates from main electrode surface in form uniform discharge. A uniform-like low-impedance discharge channel forms first cathode side subgap. Then several streamer-like high-impedance channels later anode Therefore, overvoltage after forms. intensity indicates that subgap breaks down. When injection time preionization...

Ultraviolet (UV) illumination can effectively shorten the statistical lag and jitter in gas breakdown processes. The spark gap discharge produce abundant spectrum including UV waveband. In this paper, a simple but reliable operating with N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> at atmospheric pressure is used to test optical radiation characteristics, such as intensity, rise time, fall duration of pulse, which are adjusted by...

In the practical operation of an electromagnetic pulse (EMP) simulator, flashover phenomenon on edge polypropylene dielectrics dominates insulation failure mode a peaking capacitor. To analyze characteristics film voltage under high-pressure SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> , experimental platform was established, and generator could output with rise time approximately 27 ns. The experiments were performed finger...

Abstract The novel hybrid self‐assembly of a carboxy‐ended hyperbranched polyester/copper complex on glass substrates is presented. Ordered, tree‐like self‐assemblies with sizes about 400–900 μm and branch widths 1 are obtained, which demonstrate an intriguing crystalline fractal structure by XRD, DSC, SEM techniques. dimension ( D f ) 1.67 suggests perfect supramolecular structure. Factors affecting the morphology self‐assembly, including time, relative humidity, concentration complex,...

An extremely compact high voltage peaking capacitor is developed. The has a pancake structure with diameter of 315 mm, thickness 59 and mass 6.1 kg. novel structural design endows the better mechanical stability reliability under hundreds kilovolts pulse an inner gas pressure more than 1.5 MPa. theoretical value self-inductance near to 17 nH. Proved by series electrical experiments, can endure high-voltage rise time about 20 ns, half-width duration around 25 amplitude up 800 kV in single...

The characteristics, breakdown probability, and statistical distribution of time delay under different du/dt in hundreds nanoseconds pulse for millimeter gaps have been investigated by employing the experimental method this paper. results indicate that both jitter are essentially decreased as slope voltage- is increased 1-, 2-, 4-mm gaps; particular, increasing value useful to obtain smaller relative deviation same electric field. probabilities analyzed a utilizing Gaussian function has...

A tunable surface tension pseudopotential lattice Boltzmann method (LBM) with an axisymmetric boundary is applied to study a droplet splashing on thin film. Our work focused the crown behavior influenced by different parameters, including Reynolds number, Weber liquid film thickness, and gravity acceleration. In addition, total kinetic energy of proposed explain evolution shape from perspective energy. Based achieved results, it found that radius changes time are unaffected these parameters...

MV pulsed switch plays a key role as the transfer in large electromagnetic pulse (EMP) simulators. To broaden range of self-triggering time, novel spark-discharge pre-ionization switch, which main gap electric field is superposed at trigger to let electrons its spark channel also become initial electrons, proposed and tested. The design idea is: always exist after breakdown, injection time should have more negligible effect on reducing jitter. experiment results under pulses with rise ~100ns...

Fano resonances have been achieved in a variety of complex plasmonic nanostructures. Here we propose novel planar structure supporting higher order resonances, nanodisk with built-in missing sectorial slice whose angle varies from 0 to 360°. The numerical results reveal that can be generated the visible wavelength range when locates certain this reduced-symmetry structure. Such result coupling between dipolar mode supported by edge and multipolar ring modes. Furthermore, effects dimension...