An efficient 2 μm room temperature Ho:YVO4 laser resonantly pumped by a 1.94 Tm:YAP is demonstrated, for the first time to our knowledge, in this Letter. Up 8.58 W of output at 2053 nm obtained with optical-to-optical conversion efficiency as much 41.2%. The beam had quality M2 factor Mx2 3.58 and My2 1.76 8 level. In addition, we also 4.18 2066 7.04 2040 from 27.8% 33.8%, respectively.

Long-wave infrared (IR) generation based on type-II (o→e+o) phase matching ZnGeP2 (ZGP) and CdSe optical parametric oscillators (OPOs) pumped by a 2.05 μm Tm,Ho:GdVO4 laser is reported. The comparisons of the bire-fringent walk-off effect oscillation threshold between ZGP OPOs are performed theoretically experimentally. For OPO, up to 419 mW output at 8.04 obtained 8 kHz pump pulse repetition frequency (PRF) with slope efficiency 7.6%. This OPO can be continuously tuned from 7.8 8.5 μm. we...

Barium fluoride (BaF2) is an inorganic scintillation material used for the detection of X∕gamma radiation due to its relatively high density, equivalent atomic number, hardness, and luminescence. BaF2 has a potential capacity be in gamma ray timing experiments prompt decay emission components. It known that light output from three components: two those at approximately 195 nm 220 with constant around 600-800 ps more intense, slow component 310 630 ns which hinders fast experiments. We report...

Traditional methods of training in ultrasound technology make it difficult for postgraduate reproductive medicine students to rapidly develop into doctors who can perform clinical examinations independently. It is necessary explore an efficient method training. The purpose this study was investigate whether the step-by-step (SBS) teaching improves diagnosis and work level graduate students. A total fifty participated room were selected at random divided two groups: a traditional control...

A cryogenic and room-temperature diode pumped Tm,Ho:YVO4 microchip laser with 0.5 mm crystal length lasing around 2 μm is demonstrated for the first time to our knowledge. Under temperature of 77K, as much 1.2 W output slope efficiency 35% respect absorbed pump power are obtained. At 5°C maximum 48mW obtained at an 503 mW, representing a 9.5% optical conversion efficiency. In addition, 8 mW single-frequency 2052.6 nm achieved room 15° C.

Dynamic security assessment (DSA) is widely used in dispatching operation systems, and calculation speed one of its most important performance indices. In this paper, a deep learning model called Siamese neural network proposed aiming to predict the transient stability indicators power system, for example critical clearing time (CCT). The method much faster than simulation suitable online analysis. Firstly, sample database constructed based on historical data; then trained, which uses static...

Abstract In this letter, 4H-SiC Schottky barrier diodes (SBDs) with Ti metal have been subjected to hydrogen treatment in a confined environment of 4% H 2 and 96% N at 150 °C. The effect on the SBDs electrical characteristics has investigated by technical computer-aided design simulation (TCAD) power device analyzer curve tracer. change parameters measured after is studied detail, related degradation mechanism discussed. It was found that affected both interface region bulk SiC SBDs. After...

Combined with the experimental construction of Hunan 110kV Shizishan intelligent substation in State Grid Corporation China, whole framework for is introduced. Further, exploration and application secondary & auxiliary control system realizing holographic perception, autonomous inspection, remote monitoring, active forewarning decision emphatically analyzed. Then, from an engineering perspective, significance in-plant joint commissioning between process related tested items are elaborated....

To be used in the research of radiation effect and rein force resistance for CCD, a camera based on linear CCD chip-TH7814A is designed by us, which should exactly reflect sensitization pixels real time. In this paper, basic architecture scheme system introduced, remote real-time data acquisition CPLD, USB, optic fiber transmitting technology represented Mostly, design realization circuit development software explained respectively detail Test show that developed paper run steadily, insure...

The removal of overload lines can cause power flow transferring, which may give rise to some transmission overload. By analysis available methods determining sections with shortcomings, this paper proposes a new way determine transmissions section based on real-time flows, and then deduce criterion security protection the redundancy normal line's flows. A control scheme wide area measurement system (WAMS) is also proposed. When there line overload, we should make decision according...

Abstract In this paper, an improved oscillation disturbance source localization method in control devices of generator is investigated. Using the dominant component electrical signals by fast Fourier transform (FFT), energy for governor system and excitation obtained separately. Then, based on direction non-periodic two systems, device level locating realized. Taking forced power accident caused too strong primary frequency modulation as example, FFT systems show that proposed can locate accurately.

Abstract Fula oil field is composed of unconsolidated sandstones, buried as deep 3500ft, with high porosity (31%) and permeability(2 Darcy), producing viscous 19-21°API on the south flank Muglad Basin. It well-known that under proper conditions formation flow characteristics can be improved by non-thermal massive sand production foamy behavior, referred to CHOPS. Integrated well completion strategies CHOPS were used increase heavy production. Limited influx provides a means for effective...

Tap-changers are important but frail components of converter transformers. It is to investigate the transients from transformer windings tap-changers. However, available models in Electromagnetic Transients Program (EMTP) cannot accurately and physically simulate transient characteristics when tap-changer works. Furthermore, parameters present rely on laboratory tests or finite element model (FEM) simulations. In this paper, a multi-winding single-phase based material parameters, structure...

Power transformers are the key equipment in power grid. Direct current (DC) bias of transformer, which often derived from solar storms, high voltage DC (HVDC) transmission and subway lines, poses a serious threat to stable operation system. To study mechanism loss increase under bias, magnetic-circuit coupling model was designed based on duality principle applied calculation excitation 110kV three-phase three-leg different injection. Subsequently, three-dimensional (3D) simulation...

The total reflection of the wave will occur twice and lightning over-voltage be increased by 2 times when along line reached in disconnect switch are derived through analysis accident 66kV transformer insulation breakdown. This lead to breakdown discharge grounded. In this case breaker is between arrester withstand residual voltage result Finally, effective preventive measures combined with practical experience proposed.

Image diagnosis is an important technique in transient process research of high-energy physics. High dynamic range scenes require high linear imaging systems. Scientific CMOS (sCMOS) image sensors have widely been used physics, nuclear medical imaging, and astronomical observation because their advantages the range. In this paper, we study gain ratio variation background value commercial sCMOS sensors. A self-adaptive fusion method proposed to realize images. The only uses low sensor...

The UHVDC system constitutes a significant component of the UHV power grid. converter transformer is high-value core equipment in system. Unfortunately, as lifespan systems increases, rate failure has risen annually, and inter-turn short circuit have become more prominent. This fault exhibits second harmonic characteristics similar to inrush current; hence, differential protection may experience extended blocking time, leading difficulties quickly detecting resolving fault. Currently, there...