共查询到20条相似文献,搜索用时 328 毫秒
1.
N. V. Gavrilov D. R. Emlin G. V. Radkovskii 《Instruments and Experimental Techniques》2000,43(2):252-256
A source of gas ions (argon, oxygen, nitrogen, etc.), the operating principle of which is based on the use of a glow discharge
in an electrode system of a wide-aperture hollow cathode and anode in a magnetic field, is described. The exit aperture diameter
of the hollow cathode, increased up to a size close to the ion beam diameter (10 cm), ensures the uniform ion emission of
the plasma generated in the discharge region near the anode. A decreased angular divergence or increased ultimate ion-beam
current density is achieved by a change in the potential drop in the space charge sheath between the plasma and the ion optics.
The source generates broad (50 cm2) slightly diverging (ω/2∼3°–5°) ion beams with energies of 300–1000 eV at a beam current density of ∼0.5 mA/cm2. 相似文献
2.
The actual regenerative braking force of an integrated starter/generator (ISG), which is varied with desired braking deceleration
and vehicle speed, is calculated based on an analysis of the required deceleration, maximum braking force of ISG, engine braking
force and state of charge (SOC) of battery. Braking force distribution strategies are presented according to the actual regenerative
braking force of ISG. To recover the vehicle’s kinetic energy maximally, braking shift rules for a mild hybrid electric vehicle
(HEV) equipped with automatic manual transmission (AMT) are brought forward and effects of transmission ratios are considered.
A test-bed is built up and regenerative braking tests are carried out. The results show that power recovered by the braking
shift rules is more than that recovered by the normal braking control rules.
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Translated from Chinese Journal of Mechanical Engineering, 2006, 42(10): 156–160 [译自: 机械工程学报] 相似文献
3.
M. E. Pinchuk A. A. Bogomaz A. V. Budin L. A. Shirochin M. A. Polyakov A. G. Leks S. Yu. Losev Ph. G. Rutberg 《Instruments and Experimental Techniques》2010,53(5):723-727
An X-ray diagnostic system for determining the metal vapor concentration in a high-current pulsed discharge in a high- and
ultrahigh-pressure gas based on a pulsed X-ray source in a spectral region of 20–50 keV and an X-ray CCD camera has been designed.
Two nanosecond generators with durations of high-voltage pulses of 10–20 and 50 ns and new through-target-type X-ray tubes
were used. Experiments on the diagnostics of a high-current discharge in an axially symmetric electrode system have been performed
at dJ/dt = 109–1011 A/s and discharge currents <1 MA. The data on the spatial distribution of metal vapors injected from the electrodes as a
result of erosion are obtained. 相似文献
4.
I. V. Lopatin Yu. Kh. Akhmadeev N. N. Koval’ P. M. Shchanin 《Instruments and Experimental Techniques》2011,54(1):141-146
The results of studying nonself-sustained glow discharges in an electrode system with a hollow cathode with a volume of 0.25
m3 are presented. A high-current (up to 35 A) nonself-sustained glow discharge at low pressures (0.3–1.0 Pa) is initiated and
sustained with the help of an auxiliary cold-hollow-cathode arc discharge. When the current of a nonself-sustained glow discharge
increases from 2 to 35 A, its burning voltage changes from 40 to 300 V. These values are much lower than the voltage for a
self-sustained glow discharge in the same electrode system. At a discharge current of 30 A, the electron concentration at
the center of the hollow cathode is n
e
∼ 1010–1011 cm−3 and the electron temperature is T
e
≈ 2 eV. The discharge considered can be used in the system for modification of materials and products. 相似文献
5.
Woo-Suk Seo Soon-Young Yang Byung-Ryong Lee Kyoung-Kwan Ahn Young-Bog Ham 《Journal of Mechanical Science and Technology》2007,21(8):1320-1327
This paper presents the design, fabrication, and experimental investigation of a novel planar pump using electro-conjugate
fluid. The electro-conjugate fluid (ECF) is a kind of dielectric functional fluid which generates a powerful jet flow (ECF-jet)
when a static electric field is applied via a pair of rod-like electrodes. This phenomenon that ECF can generate jet flows
from the positive electrode to the ground electrode in an applied electric field is called the ECF effect, and converts electric
energy directly into kinetic energy of the fluid. The ECF-jet acts directly on the working fluids; therefore, the proposed
planar ECF pump requires no moving parts and produces no vibration or noise. The fabricated planar ECF pump consists of three
parts: a pump base, a top cover, and an electrode substrate with dimensions of 280 mm × 190 mm × 1 mm. In this paper, five
different electrode patterns and three different flow channel heights were investigated for the realization of a high-performance
planar ECF pump. Each array of electrodes was patterned on the glass epoxy substrates using a wet-etching process, and the
flow channel heights were either 200 μm, 300 μm, or 500 μm. The pumping experiments used FF-1EHA2 as the working fluid. Experimentation showed that a no-load flow rate of 5.5 cm3/s, maximum output pressure of 7.2 kPa, and maximum output power of 11.6 mW were achieved at an applied voltage of 2.0 kV. 相似文献
6.
The principle of operation and characteristics of a broad electron beam source based on the discharge with a self-heated hollow
cathode and widened anode part are described. The source is intended for the ion nitriding of metals in the electron beam
plasma. The influence of the current density (1–7 mA/cm2) and ion energy (0.1–0.3 keV) on the nitriding rate of the 12X18H10T austenitic stainless steel is studied. It is shown that
the maximal nitriding rate is reached by the combining of the minimal bias voltage across the samples (100 V) and maximal
ion current density, which ensures the dynamic oxide layer sputtering on the sample surface. The electron source, in which
electrons are extracted through a stabilizing grid in the direction normal to the axis of the hollow cathode, ensures the
radially divergent electron beam formation with a 700-cm2 initial cross section, a current of up to 30 A, and initial electron energy of 0.1–0.5 keV. The source stably operates at
nitrogen-argon mixture pressures of up to 3 Pa. 相似文献
7.
I. L. Bogdankevich P. S. Strelkov V. P. Tarakanov D. K. Ul'yanov A. G. Shkvarunets Y. Calliez R. Wioland 《Instruments and Experimental Techniques》2000,43(1):82-87
A calorimetric spectrometer measuring individual pulses radiated by wideband relativistic microwave oscillators is described.
The calorimetric spectrometer comprises two calorimeters and a set of low-pass filters. In the development of such a spectrometer,
the basic feature consists in the high radiation power (∼108 W) and low pulse energy (∼1 J). To prevent the microwave surface discharge, the calorimeters have a rather large area (∼0.1
m2). The calorimeters’ sensitivity is 0.05 J. Frequency responses of the filters were measured experimentally and calculated
with the help of a three-dimensional version of the KARAT computer code. The experimental spectrum of a wideband relativistic
microwave plasma oscillator measured in a frequency range of 5–40 GHz is presented. 相似文献
8.
F. Ya. Zagulov V. V. Kladukhin D. L. Kuznetsov S. K. Lyubutin Yu. N. Novoselov S. N. Rukin B. G. Slovikovskii E. A. Kharlov 《Instruments and Experimental Techniques》2000,43(5):647-651
A compact nanosecond electron accelerator with an output energy of up to 4000 keV, a pulsed power of 100–180 MW, a beam current
of 0.25–1.1 kA, and a pulse energy of 5–7 J is described. The accelerator operates with a pulse repetition rate of 200 Hz
and ensures an average beam power of up to 1 kW. A nanosecond generator with a solid-state switching system, which is based
on magnetic stages of pulse compression and a semiconductor opening switch, is used as a supplying device. The design and
electric circuit of the accelerator are described, and test results are presented. 相似文献
9.
P. G. Naumov I. S. Lyubutin K. V. Frolov E. I. Demikhov 《Instruments and Experimental Techniques》2010,53(5):770-776
A closed cycle cryostat intended for optical and M?ssbauer investigations in the temperature range 4.2–300 K is described.
Samples are cooled owing to the operation of a two-stage closed-cycle cryogenic refrigerator (CR) based on the Gifford-MacMahon
cycle (with a refrigerating capacity of 1 W at T = 4.2 K at the second stage). The minimum temperature reached at the second stage of the CR was 2.7 K. The methods for reducing
vibrations transferred from the CR to a sample are described in detail. The design proposed makes it possible to reduce the
vibrational broadening of the resonance M?ssbauer lines to a level of 10–15% at 5 K, thus exceeding the level of the best
cryostat prototypes in the world. 相似文献
10.
R. A. Astabatyan M. P. Ivanov S. M. Lukyanov E. R. Markaryan V. A. Maslov Yu. E. Penionzhkevich R. V. Revenko 《Instruments and Experimental Techniques》2012,55(3):335-343
A setup for identifying low-energy (1–10 MeV) ions with charges Z ≥ 1 by simultaneously measuring the energy losses and the time of flight is described. The setup is composed of a multiwire proportional chamber and a strip silicon detector, which are used to measure the ion energy, and two low-pressure avalanche wireless detectors for measuring the energy losses and the time of flight. Results obtained in measuring α particles from 226Ra source and p, Be, C, and O ions produced on the ITs-100 cyclotron at the Flerov Laboratory of Nuclear Reactions are presented. 相似文献
11.
T. Ussing L. V. Petersen C. B. Nielsen B. Helbo L. Højslet 《The International Journal of Advanced Manufacturing Technology》2007,33(1-2):198-205
The use of laser welding for joining micro parts has experienced a substantial increase in popularity during recent years.
Specifically translucent microfluidic devices are assembled using laser welding; however, a major issue is the laser beam
size of commercially available laser-welding equipment and thus the resulting welding seam size, which may be orders of magnitude
larger than microfluidic channels and structures. We have successfully achieved extremely small welding seams using focussed
low-power laser diodes. Commercial laser welding stations for polymer assembly will typically operate in the power-region
15–50 Watts. The focussed laser beam will have a size of typically 500 μm × 500 μm and may, depending on optical configuration,
be up to several mm2. The resulting welding-seam will thus be in the area of 300–600 μm depending on beam energy distribution; additionally the
melt will spread to unheated areas due to capillary forces. As microfluidic channels are in 20–100 μm regions, even a very
limited amount of stray melt may completely fill a part of a channel and thus render it useless. We have used commercially
available “single-die” laser-diodes of optical power 200–500 mW. The beam has been focussed and directed using simple optical
installations, resulting in a beam-size in the area of 50 μm × 5 μm full width half maximum (FWHM) We have achieved firm welding
seams of width <10 μm, with a welding speed of 15 mm/s and with virtually no noticeable spread of melt. 相似文献
12.
Effects on mechanical properties in electron beam welding of TC4 alloy by laser shock processing 总被引:1,自引:0,他引:1
Lu Jinzhong Zhang Yongkang Kong Dejun Ren Xudong Ge Tao Zou Shikun 《Frontiers of Mechanical Engineering in China》2007,2(4):478-482
The surface of TC4 titanium alloy welding line by electron beam welding (EBW) was processed by high power Q-switched and repetition-rate
Nd: glass laser. Effects of laser power and spot diameter on residual stress and microhardness of the TC4 alloy welding line
by laser shock processing (LSP) have been analyzed. Results show that residual stresses almost do not change as laser power
is 45.9 J, spot diameter is ϕ9 mm; While laser power is 45.9 J, spot diameter less than ϕ3 mm, the distribution of residual
stress in welding line occurs obvious variation, which residual stress increase obviously with spot diameter decrease. When
power density is bigger than 1.8 × 1010 W/cm2, residual stresses of electron beam welding line occur change by LSP, which improve obviously residual stress distribution;
while laser power is bigger than 1.2 × 1010 W/cm2, the surface micro-hardness of electron beam welding line occurs change by LSP, which improve obviously micro-hardness distribution.
Mechanical properties of TC4 titanium alloy welding line will be improved by LSP, which provides experimental foundation for
further controlling the distributions of residual stress and micro-hardness during laser shock processing.
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Translated from Journal of Jiangsu University (Natural Science), 2006, 27(3): 207–210 [译自: 江苏大学学报 (自然科学版)] 相似文献
13.
G. S. Vorobyov M. V. Petrovsky A. A. Rybalko Yu. V. Shulga 《Instruments and Experimental Techniques》2012,55(1):56-58
Circuits and principle of operation of quasioptical power dividers based on two-row periodic structures, formed by grids of
metal bars and a dielectric waveguide placed along their longitudinal axis, are described. The experimental studies of power
divider prototypes in a frequency range of 60–80 GHz have shown a possibility of regulating the emitted power level in the
main divider arm by changing longitudinal and angular coordinates of the two-row periodic structure, which can be used for
designing quasioptical attenuators. 相似文献
14.
Yu. G. Yushkov V. A. Burdovitsin A. V. Medovnik E. M. Oks 《Instruments and Experimental Techniques》2011,54(2):226-229
A plasma electron source designed for generation of a pulsed wide-aperture electron beam in the forevacuum pressure range
(5–20 Pa) is described. The source is based on the use of a hollow-cathode glow discharge. At an accelerating voltage of 20
kV, a current pulse length of 100 μs, and a pulse repetition rate of 10 Hz, the electron beam current is 100 A, and the maximum
density of the beam pulse power is 10 J/cm2. The obtained parameters of the electron beam and the features of the source functioning in the forevacuum pressure range
show that this source can be used to good effect to modify the surface properties of nonconducting materials. 相似文献
15.
A. V. Bakaldin S. A. Voronov A. M. Galper S. V. Koldashov K. A. Lipatov M. O. Farber 《Instruments and Experimental Techniques》2010,53(4):490-499
We discuss the results of comparison and optimization of (ΔE − E) methods for identifying nuclei with the aid of a multilayer Si detector that will be used in the MONICA satellite-based
experiment aimed at studying the nuclear component of cosmic rays from hydrogen to nickel in the energy range of 10–300 MeV/nucleon.
The residual-range and Bethe-Bloch curve approximation methods are considered. Using the GEANT4 simulation, it is shown that
the Bethe-Bloch curve approximation method not only ensures a better mass resolution (which is particularly important for
identification of heavy nuclei), but also provides a means for identifying “drift” nuclei with satisfactory charge (<0.3)
and energy (<3%) resolutions. The results can be used to prepare new experiments in which (ΔE − E) nuclear identification methods are expected to be employed. 相似文献
16.
A. A. General V. A. Kel’man Yu. V. Zhmenjak Yu. O. Shpenik 《Instruments and Experimental Techniques》2010,53(4):558-560
The emission and energy characteristics of a UV source based on water vapors, which was excited by a longitudinal pulsed-periodic
discharge, are presented. The emission in the spectral range 280–340 nm was studied. The average emission power of gas-discharge
plasma of low-pressure (∼130 Pa) water vapors in the UV region was 75 mW. 相似文献
17.
G. G. Sikharulidze 《Instruments and Experimental Techniques》2009,52(2):242-244
To perform direct elemental analysis of solids, it is proposed to complement an Element 2 ICP mass spectrometer commercially
produced by Thermo Electron Corp. with a glow-discharge ion source based on a hollow cathode. The analyzed sample, in the
form of a rod 1.0–2.5 mm in diameter and 15–20 mm in length, is set along the axis of the cathode cavity with an inner diameter
of 15–16 mm and a depth of 15 mm. The cathode is placed in a discharge chamber, which, using a viton seal, is substituted
for the ICP-source sampler. The use of a plasma mirror and getter evacuation of the source chamber allows a decrease in the
source’s hydrocarbon background by a factor of 103–104. The ion source is evacuated by a mechanical pump of the mass spectrometer and an additional turbomolecular pump. Ion sources
in a mass spectrometer are replaced (a change from one analytical method to another) within 5 min. The ion current extracted
from the IS allows analysis of conducting solids with a sensitivity at a level of several ppb (10−7%) at a resolution of the mass spectrometer of 4000. Combining two easily replaceable ICP and GD ion sources in a single high-resolution
analyzer significantly extends the analytical capabilities of the Element 2 mass spectrometer.
Original Russian Text ? G.G. Sikharulidze, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 98–100. 相似文献
18.
An ionization chamber with an operating supply voltage of 10 V has been designed for use at the ITER. The sensitivity of the
chamber filled with air at atmospheric pressure is 100–200 times higher than the sensitivity of the chamber pumped down to
a pressure of 10−3–10−4 Torr. It is shown that application of the supply voltage modulation technique allows the pickup noise to be substantially
reduced; as a result, the amplifier can be located at a large (70–100 m) distance from the chamber. Results of the experiments
aimed at testing this technique on the T-10 facility are described.
Original Russian Text ? Yu.V. Gott, M.M. Stepanenko, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp.
117–121. 相似文献
19.
A. G. Turyanskii 《Instruments and Experimental Techniques》2009,52(4):587-594
X-ray prism spectrometry schemes for experimental investigations of fast processes are considered. Diamond and beryllium prism
dispersion parameters and special features of transmission spectra for crystal prisms are analyzed. It is shown that relative
energy resolution E/ΔE at photon energies E ∼ 10 keV may reach 103–104 and the total working spectral band is ∼100 keV. This opens unique possibilities for measuring fine structures of single-shot
absorption spectra for quasi-parallel beams and continuous monitoring of the fundamental and high-frequency harmonics of an
X-ray free electron laser.
Original Russian Text ? A.G. Tur’yanskii, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 4, pp. 150–158. 相似文献
20.
Duygu Evin 《Journal of Mechanical Science and Technology》2011,25(10):2711-2718
The literature surveyed revealed that drying kinetics of white mulberry under microwave treatment has not been investigated.
In present study, both experimental study and mathematical modeling on microwave drying of white mulberry was performed. The
microwave drying process which reduced the moisture content of mulberry from 3.76 to 0.25 (g water/g dry matter) was carried
out at 90, 180, 360, 600, and 800 W in a modified microwave drying set-up. The effects of microwave drying technique on the
moisture ratio and drying rate of white mulberry were investigated experimentally. Both the effects of microwave power level
(under the range of 90–800W) and initial sample weight (50–150g) were studied. No constant rate period was observed. Mathematical
modeling of thin layer drying kinetics of white mulberry under microwave treatment was also investigated by fitting the experimental
drying data to eight thin layer drying models. Among the models proposed, Midilli et al. model precisely represented the microwave
drying behavior of white mulberry with the coefficient of determination higher than 0.999 and mean square of deviation (χ2) and root mean square error (RMSE) lower than 1.1×10−4 and 8.9×10−3, respectively for all the microwave drying conditions studied. The effective moisture diffusivity (Deff) of white mulberry varied from 0.45×10−8 to 3.25×10−8 m2s−1. Both the drying constant (k) and Deff increased with the increase of microwave power level. 相似文献