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In this paper, the inherent self-similarity between seismic characteristics and the dynamic behavior of a concrete gravity dam under decomposed near-fault ground motions is investigated. The representative low- and high-frequency components were decomposed using the continuous wavelet transform method to explore their effects on the dam response. The Koyna concrete gravity dam system was used as the basis for a numerical model. A series of dam dynamic responses under near-fault motion with and without pulse properties were obtained by numerical analyses. The relationship between the proposed dimensionless indices (intensity measure ratio (ΦIM), pulse period ratio (T1/Tp)), and response ratio (ΨEDP, m) was established to study the inherent self-similarity in the dynamic behavior of dams, which has an explicit physical significance with smaller dispersion. The response proportions of two main frequency components in the original near-fault record were revealed. Furthermore, a series of new threshold values were calculated based on the intersection of the pulse and high-frequency ratios, and the range of influence of the low- and high-frequency components was quantitatively divided. Finally, a predictive model was proposed for the dam responses to near-fault ground motions containing the proposed dimensionless indices that exhibited reasonable patterns. The pulse-like seismic characteristics and seismic responses to near-fault ground motions were analyzed and selected in the context of sensitivity, inherent self-similarity, threshold point, and regression error. Results show that the self-similarity between Φ S a ( T 1 ) , ΦASI and ΨDVR,pulse, Ψ DVR n , p u l s e is superior to that of other parameter ratios, indicating that more attention should be given to the role of intensity and pulse parameters in practical concrete dam seismic design.

The linear–nonlinear step load control is proposed to meet the requirements of the pulse load. The nonlinear optimal step control from absolute no-load to full-load is able to force the converter to reach the full-load steady-state operation point with the minimum output voltage drop and minimum settling time. The key is to calculate the initial switching frequency and the duty cycle of the first switching period depending on the load condition. The proposed method is realized by analytic geometry analysis on the state trajectory and confirmed in a 6.6-kW 1-kV/48-V SiC LLC converter. From no-load to full-load, the output voltage drops by 2.24 V and the settling time is 0.76 ms, which reduce by 18.8% and 79.3% compared with the conventional linear control, respectively. Under 100-Hz pulse load with the duty cycle of 30%, the output voltage drop is limited within 2.30 V and overshoot by 1.68 V.

In this study, we focus on investigating a complex modified short pulse (CSP) equation with zero boundary condition at infinity . Based on the analytical and symmetric properties of eigenfunctions and spectral matrix of its Lax pair , a Riemann-Hilbert problem for the initial-value problem of the CSP equation is established. The one-soliton solutions and breather-type solutions of the CSP equation are further given by solving the Riemann-Hilbert problem.

We characterize the frequency response of channel-interleaved photonic analog-to-digital converters (CI-PADCs) theoretically and experimentally. The CI-PADC is composed of a photonic frontend for photonic sampling and an electronic backend for quantization. The photonic frontend includes a photonic sampling pulse generator for directly high-speed sampling and an optical time-division demultiplexer (OTDM) for channel demultiplexing. It is found that the frequency response of the CI-PADC is influenced by both the photonic sampling pulses and the OTDM, of which the combined impact can be characterized through demultiplexed pulse trains. First, the frequency response can be divided into multiple frequency intervals and the range of the frequency interval equals the repetition rate of demultiplexed pulse trains. Second, the analog bandwidth of the CI-PADC is determined by the optical spectral bandwidth of demultiplexed pulse trains which is broadened in the OTDM. Further, the effect of the OTDM is essential for enlarging the analog bandwidth of the CI-PADC employing the photonic sampling pulses with a limited optical spectral bandwidth., Comment: 11 pages, 8 figures

Free Electron Lasers (FEL) use free electrons in the periodic permanent magnetic field of an undulator as a gain medium. They extend from far infrared to X-rays, they are easily tunable and provide a high peak power. The advent of tunable intense (few mJ) short pulse (down to the attosecond regime) FELs with record multi GW peak power in the X-ray domain enables to explore new scientific areas. These unprecedent X-ray sources come along with versatile performance.

To solve the problem of difficulty in dust removal from single-filter cartridge dust collector equipment in confined space, an orthogonal experimental design and numerical simulation methods were adopted to optimize the ash-cleaning device. The study found that the diameter of the cone base has a greater impact on the pulse cleaning performance of the dust collector than the angle of the cone, and the installation height L has the least impact. When the optimal parameters θ = 55°, D = 80 mm, L = 0 mm, compared with the traditional dust collector, the average dust concentration at the outlet of the equipment is reduced by 11.5%, the number of cleanings is reduced by 37.5%, and the pressure at the lower part of the filter cartridge is reduced. 34.7%, the upper part increased by about 53.9%. The problem of uneven cleaning of filter cartridges in confined spaces is solved, and equipment performance is improved.

This brief presents a low-power counter-based adaptive equalizer that does not require additional power-hungry comparators for an equalizer adaptation loop. A pulse generator in the proposed equalizer obviates the need for additional error sampling comparators. Instead, it allows the receiver to utilize an output of a data decision comparator for the equalizer adaptation by generating a pulse that indicates whether the comparator makes a firm decision for the incoming data. A single comparator is shared by the data recovery path and equalizer adaptation loop. Consequently, the proposed counter-based equalizer achieves a low power dissipation owing to the reduced number of comparators. Fabricated in a 28-nm CMOS technology, the prototype receiver occupies an active area of 0.004 mm2 and consumes only 0.99-pJ/b at 15-Gb/s.

Discrete breathers are spatially localized periodic solutions in nonlinear lattices. We prove the existence of odd symmetric, even symmetric, and multi-pulse discrete breathers in strong localization regime in one-dimensional infinite Fermi-Pasta-Ulam lattices with even interaction potentials. The multi-pulse discrete breather consists of an arbitrary number of the odd-like and/or even-like primary discrete breathers located separately on the lattice. The proof applies to both cases of pure attractive and repulsive-attractive interaction potentials.

For thermal fire detectors with a thermoresistive sensitive element, the method of determining its time parameters is justified. The time parameters of operation and the time constant of the thermal fire detector are considered as time parameters. The method is based on the use of the Joule-Lenz effect, for the implementation of which single pulses of electric current are passed through the thermoresistive sensitive element of the fire detector. Pulses having the shape of a quarter sinusoid or a quarter cosinusoid are used as such test signals. Using the Laplace integral transformation, analytical expressions are obtained, which represent the formalization of the reaction of the thermoresistive sensitive element of the fire detector to the corresponding test signals. These analytical expressions are used to obtain the functional dependences of the fire detector time constants on the pulse duration of the electric current and the auxiliary parameter. The auxiliary parameter is the ratio of the values ​​of the output signal of the thermal fire detector at two fixed points in time. This choice of auxiliary parameter allows to ensure invariance with respect to the transfer coefficient of the thermal fire detector with a thermoresistive sensing element. The fixed moments of time are chosen to be equal to half and three quarters of the duration of the pulses of electric current flowing through the thermoresistive sensitive element of the fire detector. The time of operation of the thermal fire detector is determined in the form of two additive components, one of which is a time constant of the fire detector, and the other is determined by the values ​​of normalized parameters in accordance with existing regulations. A sequence of procedures is given, which together represent a method of determining the time parameters of thermal fire detectors of this type.

Three types of pulses, namely the control, drive, and power pulses, coexist in power electronics systems. The transmission of them embodies the idea to control energy flow with signal flow. However, due to the nonideal performance of the semiconductor switches and the parasitic elements, significant delay and distortion are inevitable during the transmission, causing severe challenges in terms of both device- and system-level performance. Taking silicon carbide (SiC) MOSFET-based system as an example, this article studies the transmission of the three pulses. Time-domain studies are provided first to derive the characteristic parameters of the delay and distortion. Based on the time-domain expressions, a pulse decomposition method is proposed to study the frequency spectrum of the power pulse considering all major transient factors. Experimental results are provided to verify the proposed method and the acquired results. Based on the analyses, the impact of pulse delay and distortion on system performance is summarized, and the general idea of active gate controlling for the power pulse is briefly discussed. This article provides quantitative studies and relevant discussions from the perspective of pulse transmission to improve the analysis, gate-drive design, and active gate control of switching transient.

We present a new approach of the passive microwave pulse compression for gigawatt power generation. Two stages of resonant-cavity-based pulse compressors are cascaded and the peak power gain is multiplied to 12. Candidate passive pulse compressors and cascaded schemes are studied theoretically from the perspective of a linear time-invariant (LTI) system. The compact $S$ -band (2.856 GHz) prototype system consists of six correction cavities and two storage cavities, with the ability to flatten the first-stage pulses and generate the two-stage compressed pulses with exponentially decaying waveforms. It compresses power pulses of 100 MW and $3.6~\mu \text{s}$ generated by commercial klystrons to the peak power of 1.2 GW and full-width at half-maximum (FWHM) pulse durations of 100 ns. The pulse phase is controllable and the power can be combined for either input sources or outputs. This would be attractive to various applications, such as high gradient accelerator and hot dense plasma generation.

In this article, a new modular structure of Marx generators (MGs) based on interleaved boost converter is proposed. The converter operates in discontinuous conduction mode to generate a high-voltage pulsed power with a common low-voltage source. Unlimited stages can be added to the proposed structure to reach lower maximum voltage stress for the semiconductors or to generate several kilovolts of the output pulses, while the voltage of the semiconductors remains constant. This structure resulted in a higher pulse repetition rate, fewer semiconductor elements, and lower semiconductor voltage stress in comparison to conventional MGs. Hence, the proposed structure is applicable for and efficient in supplying plasma applications with high-voltage pulses. The theoretical foundation of the introduced converter is presented and its performance is simulated using OrCAD software. Based on the obtained results, the maximum voltage of the output pulse is 40 times the input voltage in a single-stage structure. An 80-W prototype of the proposed structure was built to validate the accuracy of the theoretical foundation and the simulation results.

This article investigates nonlinear self-focusing of an intense right hand circularly polarized Gaussian profile laser pulse in a weakly relativistic and ponderomotive regime inside a collisionless and unmagnetized warm quantum plasma. The nonlinear propagation equation for laser pulse in plasma has been derived. Then, the evolution differential equation for laser spot-size was obtained with considering the parabolic equation approach under the Wentzel-Kramers-Brillouin and paraxial ray approximations. This differential equation was solved numerically by fourth-order Runge-Kutta method. It is shown that our solution confirms the results of the self-focusing of the laser pulse in a weakly relativistic ponderomotive regime in cold quantum plasma in extreme conditions. Numerical results indicate that self-focusing of the laser pulse in the presence of relativistic and ponderomotive nonlinearity inside warm quantum plasma is improved in comparison with relativistic and ponderomotive cold quantum plasma.

A variety of complex nonlinear optical effects are emerged when water is radiated by ultrafast laser with high pulse energy, which induces different underwater ablation morphologies compared with those ablated in air. A numerical model describing the free electron evolution of water medium during one pulse cycle is established to fully understand the plasmas defocusing effect in multiple pulses. Combining with the Kerr self-focusing and laser diffraction effects, the refractive index change of water medium under different pulse energies and repetition rates can be quantitatively analyzed. Three different experimental phenomena between ultrafast laser and water (plasma ball, laser filamentation, beam diffusion) are well explained by the numerical results. These three nonlinear optical phenomena demonstrate the difference of the material removal under water and in air.

A time-dependent model of pulse-driven collisional inhomogeneous sheath is proposed for dual frequency (DF) capacitively coupled plasma (CCP). A pulse-modulated low frequency (lf) source and a high frequency (hf) source are concurrently applied to the power electrode. Ionfluid equations are used to calculate the spatio-temporal variation of sheath width and sheath potential. In this model, we excluded the time-dependent terms of ion fluid equations, whereas the electric field, ion motion and ion density are considered time-dependent. The predicted sheath potential and width are compared and collated with those of time-dependent continuous DF CCP collisional sheath and time-dependent pulse-driven DF CCP collisional sheath models. From the evaluation of temporal variation in sheath width and potential, it is observed that pulse-driven DF CCP predicts higher value of sheath parameters than conventional continuous RF-driven DF CCP. From the temporal variations of sheath width, it was found that duty cycle of pulse modulator significantly affects the sheath width when duty cycle is less than 50%. Moreover, wider sheath width and higher sheath potential can be achieved using both the pulse-modulated lf source and hf RF source.

In general, pulsed lasers with high peak power have been used for the micro-groove formation. However, the processing speed is limited by the pulse repetition rate. On the other hand, CW laser can be expected to perform the high-speed processing by continuous energy input. The mechanism of micro-groove formation by CW laser was investigated by high-speed observation and the thermal fluid analysis. In the perpendicular irradiation of CW laser, the molten metal flows symmetrically around the keyhole to the backward direction, and micro-grooves remain at both edges of molten region. In contrast, in the angled irradiation, the molten metal at the reflection-side scatters as spatters. The remained molten metal flows from the reflection-side to the incident-side through the bottom of keyhole, since the recoil pressure is generated from the reflection-side to the incident-side. In addition, high-speed scanning contributes to keeping the sufficient time and force to move the molten metal in the backward direction. Then, the micro-groove remains at the reflection-side, while the upheaval is formed at the incident-side by gathering the molten metal from the reflection-side and the front of keyhole. Asymmetrical behavior of molten metal flow in angled irradiation of CW laser can create micro-groove in the reflection-side.

Due to the growth of bulk cargo transportation by road, it is necessary to increase the level of mechanization and automation of loading and unloading operations. In recent years, various powerful high-performance unloading machines of original designs (car tippers, vibrating platforms, elevators, etc.) have been created to mechanize unloading processes. This makes it possible to speed up unloading, reduce costs and reduce excessive downtime of dump trucks under unloading. However, the use of such machines is cost-effective at unloading points with a turnover of more than 30 dump trucks per day. Therefore, the problem of creating simple and cheap equipment that ensures efficient unloading of dump trucks with bulk cargo, as well as cleaning of rolling stock from cargo residues, as regardless of the type and composition of cargo, some of them are delayed on the floor, in stamped ribs. pockets of all-metal body walls. The largest amount of cargo remains on the hatch covers, the angle of which is on average 300, while the angle of the actual slope of the cargo reaches 450 and more. Due to this ratio of angles, even dry material cannot fall out completely through the hatch opening, let alone moistened or viscous bulk cargoes. The amount of bulk cargo residues depends on many factors (type of cargo, its humidity, size of pieces, air temperature, distance of transportation, method of unloading) and can be from 2 to 30% of the total weight of the cargo [1]. The use of useful vibrations allows to solve this problem the most expediently. Therefore, the development of a vibratory shock device for unloading vehicles is a promising and urgent task.

In X-ray spectrum analysis, the pulse pile-up is a long-standing issue which deteriorates the energy resolution and count rates of the radiation detection systems. In this study, a novel pulse pile-up identification method based on particle swarm optimization and double-layer parameter identification model (PSO-DLPIM) is proposed. Different Gaussian pile-up waveforms are realized by exponential pulse through Sallen-Key (S-K) low-pass filtering. Then, the proposed model recognizes the parameters of each sub-Gaussian pulse. Especially, it can be used to modelling the pulse indirectly without a certain model parameter and overcomes the model mismatch troubles. Finally, computer simulations and experimental tests are carried out and the results show that this method has higher accuracy for the recognition of pile-up pulses. The example shows that the minimum distance between pulses that can be identified by this method is 0.05 μs. And when the pulse generation time is known and the environmental noise is low, the relative error of the amplitude of pulse pile-up recognition is as low as 0.15%. Therefore, this method can greatly improve the resolution of the X-ray spectrum.

Pulse-like near-source ground motions were observed by the local network during the 2015 Mw 8.3 Illapel, Chile earthquake. Such ground motions can be quite damaging to a wide range of infrastructures. The primary objective of this study is to provide a source model that can explain such ground motions. The isolated nature of the pulses indicated that the rupture of some small isolated region on the fault contributed to the generation of the pulse. Therefore, we considered such regions and termed them as Strong Motion Pulse Generation Areas (SPGAs). We used the corrected empirical Green's function (EGF) method because this method has been successfully applied to near-source pulse-like ground motions in previous studies. We simulated synthetic waveforms using the frequency dependent quality factor Q=239f0.71 and empirical site amplification factors, which we obtained by applying a generalized inversion technique to local weak-motion data. The result indicated that the observed ground motions from the Mw 8.3 Illapel earthquake can readily be explained with a source model that involves two SPGAs with dimensions of several kilometers in spite of the huge rupture zone of the earthquake. The source model can reproduce velocity waveforms, acceleration Fourier amplitude spectra (FAS) and pseudoacceleration response spectra. It also reproduces the duration of strong ground motions quite accurately. No significant bias was found with respect to distance and frequency. In conclusion, the corrected EGF method is a very efficient tool to simulate near-source ground motions of a subduction earthquake when it is combined with higher stress-drop subevents whose sizes are adjusted to the observed pulse widths.

Path planning is the basis and prerequisite for unmanned aerial vehicle (UAV) to perform tasks, and it is important to achieve precise location in path planning. This paper focuses on solving the UAV path planning problem under the constraint of system positioning error. Some nodes can re-initiate the accumulated flight error to zero and this type of scenario can be modeled as the resource-constrained shortest path problem with re-initialization (RCSPP-R). The additional re-initiation conditions expand the set of viable paths for the original constrained shortest path problem and increasing the search cost. To solve the problem, an effective preprocessing method is proposed to reduce the network nodes. At the same time, a relaxed pruning strategy is introduced into the traditional Pulse algorithm to reduce the search space and avoid more redundant calculations on unfavorable scalable nodes by the proposed heuristic search strategy. To evaluate the accuracy and effectiveness of the proposed algorithm, some numerical experiments were carried out. The results indicate that the three strategies can reduce the search space by 99%, 97% and 80%, respectively, and in the case of a large network, the heuristic algorithm combining the three strategies can improve the efficiency by an average of 80% compared to some classical solution.

The recent expansion of trade measures across countries in sub-Saharan Africa provides market opportunities for the agri-food sector. However, price signals and changes across domestic and regional...

Propagation effects in the interstellar medium and intrinsic profile changes can cause variability in the timing of pulsars, which limits the accuracy of fundamental science done via pulsar timing. One of the best timing pulsars, PSR J1713+0747, has gone through two ‘dip’ events in its dispersion measure (DM) time series. If these events reflect real changes in electron column density, they should lead to multiple imaging. We show that the events are well fitted by an underdense corrugated sheet model, and look for associated variability in the pulse profile using principal component analysis. We find that there are transient pulse profile variations, but they vary in concert with the DM, unlike what is expected from lensing due to a corrugated sheet. The change is consistent in shape across profiles from both the Green Bank and Arecibo radio observatories, and its amplitude appears to be achromatic across the 820-MHz, 1.4-GHz, and 2.3-GHz bands, again unlike expected from interference between lensed images. This result is puzzling. We note that some of the predicted lensing effects would need higher time and frequency resolution data than used in this analysis. Future events appear likely, and storing baseband data or keeping multiple time–frequency resolutions will allow more in-depth study of propagation effects and hence improvements to pulsar timing accuracy.

Ultrafine-grained (UFG) Cu deposits were prepared using pulse electrodeposition assisted by hard particle friction under strong cathodic polarisation in an additive-free bath. The effects of hard p...

Carbon fiber reinforced polymer (CFRP) laminates are extensively used in aviation due to their excellent material properties. Damages resulted from manufacturing or usage seriously undermine the sa...

Based on the transverse polarization modulation technology of MgO:LN crystal, an electro-optic cavity-dumped 946 nm all-solid-state laser with short pulse duration and high peak power at 200 Hz rep...

Moving the fiber laser emission to the region below one micron may provide a cheaper, more compact and robust alternatives to the existing solid state lasers. Here, for the first time we report a neodymium mode-locked fiber laser emitting at 905 nm in the all-fiber polarization maintaining configuration. We obtain a self-starting pulse generation in nonlinear amplifying loop mirror (NALM) cavity configuration. To suppress a dominant emission at 1064 nm corresponding to a 4-level laser scheme, we use an active fiber - 920/1064 division multiplexer - active fiber sandwich-like sequence in the NALM loop. A rectangular shape dissipative soliton had nJ energy, 30 pm spectral width and 80 - 430 ps width linearly depending on the pump power. Excellent agreement with numerical simulation allowed us to recover pulse shape and width for the pulses out of autocorrelation window., Comment: 7 pages, 4 figures

Although receptivity plays a key role in the transition of hypersonic flows, most prior computational receptivity studies have neglected to study broadband frequency disturbance spectra. This work ...

We establish the conditions under which collisions of electrons with ions affect the generation of terahertz radiation at normal incidence of a laser pulse on a dense plasma in a constant magnetic field. If during the time of exposure to the laser pulse, the number of collisions of electrons occurred is not small, then the amplitude of generated magnetic field decreases, the shape of the generated pulse changes, and the total energy of terahertz radiation decreases. The influence of collisions on the generation of terahertz radiation manifests itself in a relatively weak magnetic field, when the electron cyclotron frequency is lower than the plasma frequency.

In this letter, excitation of discrete levels in a quantum system is considered, when the duration of the driving pulse is changed from multi-cycle to ultra-short half-cycle regime. It is shown that, as the number of optical cycles decreases, the system passes from the periodic-driven regime to the “kick-driven” action. In both cases the effect depends on the pulse area. However for subcycle pulses the area is equal to the time integral of the field strength, whereas for multi-cycle pulses it is determined by the time integral of the pulse envelope. The interference of the envelope pulse area and the electric pulse area and its possible manifestations in experiments are discussed.

As a kind of high power pulse power supply, the air-core compensated pulse alternator (CPA) is widely used in electromagnetic emission, laser weapon, pulse capacitor charging, and other fields. A brush structure or a brushless structure can be used in the air-core CPA. Because the brushless structure is more suitable for high-speed operation and has higher reliability, more and more scholars have studied the brushless structure air-core CPA. In this article, an electric excitation brushless air-core CPA which the equivalent pole-pairs number is one is proposed. The CPA adopts a brushless rotor winding designed based on the principle of magnetic field differential modulation, which can simultaneously produce two and three pole-pair magnetic fields rotating in the same direction. The rotor winding can couple the field winding and the armature winding at the same time, thus realize electromechanical energy conversion. Under the same conditions, the pulsewidth of pulse discharge current can be significantly increased by reducing the number of pole pairs of the CPA and the output energy of a single pulse can be improved. In this article, a detailed design method of the differential modulation rotor winding of the CPA is presented, and the harmonic content of the CPA is calculated by analytical and numerical methods. Finally, the finite element model is used to analyze the related performance of the CPA, and the analysis results verify the effectiveness of the design scheme.

The African continent is growing at a fast pace, and its economic pulse has heightened. However, there is a growing momentum within the community of researchers, businesses, and investors to make an overall survey and assessment of progress sustained in the African space industries as a whole. There is no debate on the fact that documentation is pivotal to every research progress. Thus far, poor documentation has been inimical to the growth of the African economy and also the African space industry. In collaborative efforts with the African Space Generation Advisory Council (SGAC) body, this article is an attempt at documenting progress, and it includes the analysis of the entrepreneurial outlook of some selected countries (Nigeria, Ghana, Morocco, Mauritius, Sudan, and Tunisia) in Africa. This study aims at sustaining the African economic drive by using a multimethod approach involving Gynawali and Fogel's "key dimensions of environments for entrepreneurship development,"to understand the economic environment in those nations while incorporating the versatile national competitive advantage diamond model of Michael Porter. Comparisons can be drawn between African countries and member nations in BRICS (Brazil, Russia, India, China, and South Africa) to obtain a conclusion toward fueling the increasing space science and technological drive in Africa. Research is essential for industries and socioeconomic development in Africa - the Last Frontier, which remains a potential ground for global commercial space growth.

Spatiotemporal mode-locked (STML) fiber lasers attract great interest owing to their distinctive spatiotemporal characteristics and potential to generate high-energy pulse. Herein, we report an all few-mode fiber figure-eight laser STML by a nonlinear amplifying loop mirror at 1.0 µm. The laser can generate single and multiple pulses at different central wavelengths. In particular, various types of bound-state solitons, such as conventional bound-state solitons and double bound-state solitons, are also achieved and further confirmed by the numerical simulations. The obtained results contribute to further understanding the nonlinear characteristics of STML fiber lasers and such a laser has potential applications in optical communications, especially in information coding.

In this paper, the method of spectral-temporal recovery of nonstationary fields of ultrashort radio pulses, whose wave configuration provides authenticators of radio images in the subnanosecond resolution signal radio vision, is developed. The technology of spectral-temporal recovery of a single radio response implies generating an identical pulse sequence and its sequential transmission via an amplifier covered by a delayed feedback loop. A parametric model of a stroboscopic recirculator is constructed and analyzed, and its stability conditions are investigated. The statistical estimate of the radio response reproducibility is given considering the influence of the recirculation mode parametric conditions, stationary noises, and iterative attenuation. The microstrip recirculator module prototype is developed, which generates a pulse sampling sequence using a finite radio response of the given configuration. It is shown that the best signal-to-noise ratio, at which the iteration number ranges from 15 to 20, is 9 dB or more.

In this paper, we present a compact memristor model for bipolar neuromorphic ReRAM devices. The proposed model focuses on the high level description of the device, and it reproduces some of the most important characteristics (i.e. conductance, energy dissipation) without needing a detailed electrical simulation. Its functionality is shown by using it to model the behavior of three different ReRAM devices that were fabricated and measured at the CNR-IMM, MDM Laboratory. The parameters extraction procedure is also discussed. The obtained results clearly show that the model proposed in this paper is able to capture the influence of the programming pulse parameters (i.e. pulse duration and height) changes. This is accomplished by the introduction of a parameter, which is related to the specific device technology.

A generator of high-voltage bipolar pulses with adjustable values of the switching frequency (0–2000 Hz) and the output-voltage amplitude (300–3600 V) with the same magnitude for pulses of different polarities has been developed. The rise time of the output voltage pulses when operating into a capacitive load of 400 pF is no more than 3 μs. The asymmetry of the effective values of the pulse voltages of different polarities at switching frequencies of 0–200 Hz is no more than 0.02%. The generator provides synchronization of the moments of switching a high voltage with the operation of the video camera of a magnetograph and other devices. The generator can be used in various fields of experimental physics related to polarization measurements.

We consider the generation of IR radiation during the interaction of a high-power ultrashort laser pulse with a gas jet using numerical simulation by the particle-in-cell method. The laser pulse parameters correspond to the capabilities of the PEARL sub-petawatt laser facility in Nizhny Novgorod (Russia) when using the compression after compressor approach (CafCA). It is demonstrated that about 1 % of the energy can be converted into radiation in the wavelength range of 5 – 10 μm.

With the technology scaling down, the single event transients produced in the combinational circuit lead to an increasing threat to reliability. In this paper, Dummy Gate Enhanced Charge Sharing (DGECS) technique is proposed to mitigate single event transients, and enhances the pulse quenching of logic cells by increasing the charge sharing between key transistors. Mixed-mode 3-D technology computer aided design simulations were carried out with commercial 65nm dual-well CMOS technology. The simulation results show that the proposed layout technique can significantly reduce single event transient pulse widths and even completely quench transient pulses.

Research is devoted to investigation of properties of pulsed explosive emission cathodes for X-ray tubes. Three types of annular explosive emission cathodes were studied: metal ceramic with slits (of a comb-shaped kind), ring metal ceramic, and carbon ceramic. A pulsed high-voltage generator used in experiments is characterized with the following parameters: voltage pulse full-width at half-maximum is about 20 ns, pulse voltage amplitude is up to 150 kV, and pulse repetition rate is up to 200 Hz. The installation makes it possible to study demountable models of pulsed X-ray tubes of different designs. Current and voltage waveforms corresponding to different operation modes and rates of rise of X-ray tube anode voltage were analyzed. The obtained characteristics of explosive cathodes depend on the cathode’s material, the shape, and the supply voltage of the primary energy storage. The current pulse duration for the ring carbon-ceramic cathode is considerably lower than that for the other cathodes, although it generates a higher radiation dose rate.