共查询到20条相似文献,搜索用时 15 毫秒
1.
V. T. Kogan D. S. Lebedev Yu. V. Chichagov I. V. Viktorov I. T. Amanbaev S. A. Vlasov 《Technical Physics》2009,54(11):1714-1720
An ion source with electron ionization is considered. The charged-particle flow at the exit from this source has a cross section
of ∼0.1 × 0.1 mm, an angle spread of 2° × 2°, a relative energy spread of <0.5%, and an energy range of 0.5–3.0 keV. This
ion source is intended for systems where an ion beam is focused in two mutually perpendicular directions. The ion source design
makes it possible to ionize a sample locally (in a volume of ∼10 mm3), where the concentration of the particles under study exceeds the concentration averaged over the volume of the vacuum chamber
of the mass spectrometer by two to three orders of magnitude. The ion-optical properties of the source are numerically simulated,
and the optimum parameters of the source are chosen. Examples of the application of the ion source are given for the mass-spectrometric
determination of metal salts in aqueous solutions and of gases and volatile compounds in samples in various phase states. 相似文献
2.
An ion-optical scheme for a portable magnetic double-focusing mass spectrometer that makes it possible to analyze several components simultaneously over a wide mass range (the mass-spectrograph operating mode) is proposed. This scheme effectively solves the research and technological problems involving the analysis of rapidly varying compositions. 相似文献
3.
C. Corredor J. Diaz J. M. Diaz H. A. Farach C. P. Poole 《Applied magnetic resonance》1995,9(3):309-317
The electron spin resonance spectra fromGallus domesticus egg shells exhibit a strong free radical singlet, a spectrum due to Mn2+ ions in a calcite site, a low field line line atg≈30/7 due to Mn2+ in a rhombic site, and spectral lines arising from Fe3+ ions. Details of the ESR spectral lines did not correlate with fertile, non-fertile or color type egg-shell characteristics. 相似文献
4.
《X射线光谱测定》2005,34(2):135-139
A new portable XRF spectrometer which allows control of the energy and the intensity stability of the emitted x‐ray beam has been designed and built. The control is obtained by measuring the x‐ray fluorescence generated by a double Ag/Ba thin target when crossed by the x‐ray beam during a measurement. The silver and barium fluorescence K lines are detected by an ancillary Si‐PIN detector and analysed by software developed at the LNS/INFN laboratories. The new portable spectrometer, the beam stability control method, the evaluation of the system and some quantitative applications of interest in the cultural heritage field are presented and discussed. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
5.
T. Tatsukawa T. Maeda H. Sasai T. Idehara M. Mekata T. Saito T. Kanemaki 《International Journal of Infrared and Millimeter Waves》1995,16(1):293-305
The development of a high frequency electron spin resonance (ESR) spectrometer with a wide frequency range using a gyrotron as the radiation power source is described.GYROTRON FU-E, optimized for use in an ESR spectrometer in the millimeter wave range, was developed in Fukui University. In order to test the normal operation of the spectrometer, the ESR of two standard samples, single crystal and polycrystalline DPPH, has been measured, in the pulsed mode over the frequency range from 65 GHz to 135 GHz. 相似文献
6.
By using a narrow single electron spin resonance (ESR) line agent, triarylmethyl, tris(8-carboxy-2,2,6,6-tetrahydroxyethylbenzo[1,2-d:4,5-d′]
bis(1,3)dithiole-4-yl)methyl sodium salt (TAM OX063), pulsed longitudinally detected ESR (LODESR) measurements of a phantom
or the chest of a living mouse at the operating frequency of ca. 300 MHz were taken and the effective longitudinal relaxation
time (T
1*) was estimated for oximetry. Under irradiation of a pair of π-pulses with a variable interval between pulses (τ), in-phase
LODESR signal intensities were obtained from the phantoms containing TAM dissolved in a physiological saline solution at a
concentration of 1 mM and various concentrations of oxygen. TheT
1* of the phantom was calculated from the plotted curve of the LODESR signal intensity against τ. It was found that the reciprocal
ofT
1*, i.e., the longitudinal relaxation rate, increased with the concentration of oxygen. In vivo pulsed LODESR measurements of
the chest of living mice that had received a TAM injection via the intraperitoneal route were made. While the LODESR measurements
were being made, the mice in one group breathed normal air and those in another group breathed 100% oxygen. It was found that
the longitudinal relaxation rate of the mice breathing 100% oxygen was significantly greater than that of mice breathing normal
air, indicating that breathing 100% oxygen elevates the thoracic longitudinal relaxation rate. 相似文献
7.
Náfrádi B Gaál R Sienkiewicz A Fehér T Forró L 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2008,195(2):206-210
We present a newly-developed microwave probe for performing sensitive high-field/multi-frequency electron spin resonance (ESR) measurements under high hydrostatic pressures. The system consists of a BeCu-made pressure-resistant vessel, which accommodates the investigated sample and a diamond microwave coupling window. The probe’s interior is completely filled with a pressure-transmitting fluid. The setup operates in reflection mode and can easily be assembled with a standard oversized microwave circuitry. The probe-head withstands hydrostatic pressures up to 1.6 GPa and interfaces with our home-built quasi-optical high-field ESR facility, operating in a millimeter/submillimeter frequency range of 105–420 GHz and in magnetic fields up to 16 T. The overall performance of the probe was tested, while studying the pressure-induced changes in the spin-relaxation mechanisms of a quasi-1D conducting polymer, KC60. The preliminary measurements revealed that the probe yields similar signal-to-noise ratio to that of commercially available low-frequency ESR spectrometers. Moreover, by observing the conduction electron spin resonance (CESR) linewidth broadening for KC60 in an unprecedented microwave frequency range of 210–420 GHz and in the pressure range of up to 1.6 GPa, we demonstrate that a combination of high-pressure ESR probe and high-field/multi-frequency spectrometer allows us to measure the spin relaxation rates in conducting spin systems, like the quasi-1D conductor, KC60. 相似文献
8.
This Letter proposes a snapshot imaging spectrometer, which obtains the spectral information and spatial information in one shot. The device proposed can achieve the data cube size of 21 × 29 × 40 in the waveband of400–800 nm. The core element of this system is the microlens array, which contains 60 × 60 microlenses in a square arrangement, each microlens has an aperture of 125 μm× 125 μm, and the F number is 15. The microlens array is mounted in a rotation mount, which provides 360° of rotation around the optical axis to maximize the spectral resolution. The final resolution of the system is about 10 nm. 相似文献
9.
Xiaofang Zhang Xiaohua Qi Mingqiang Zou Jingwei Wu 《Journal of Raman spectroscopy : JRS》2012,43(10):1487-1491
Identification of the gasoline purity is important for quality control and detection of gasoline adulteration. Principal component analysis and Raman spectroscopy were used to authenticate gasoline adulterated with methyl tert‐butyl ether (MTBE) and benzene. Gasoline could be clearly distinguished from gasoline adulterated with MTBE and benzene by a plot of the first principal component (x‐axis) against the second principal component (y‐axis). And the radial basis function neural network was used for quantitative prediction of the volume percentages of MTBE and benzene in gasoline based on Raman Spectra. The correlation coefficient (r) and mean absolute percentage error between predictive values and spiked values were 0.9907 and 0.9934 and 15.73 and 8.19%, respectively. Moreover, the Raman spectra of the samples were obtained with a portable Raman spectrometer. Therefore, the method is simple, effective, fast, does not require sample pre‐processing, and is promising for rapid gasoline detection. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
10.
The design and performance of an electron spin resonance spectrometer operating at 3 and 9 GHz microwave frequencies combined with a 9-T superconducting magnet are described. The probehead contains a compact two-loop, one gap resonator, and is inside the variable temperature insert of the magnet enabling measurements in the 0-9T magnetic field and 1.5-400 K temperature range. The spectrometer allows studies on systems where resonance occurs at fields far above the g approximately 2 paramagnetic condition such as in antiferromagnets. The low quality factor of the resonator allows time resolved experiments such as, e.g., longitudinally detected ESR. We demonstrate the performance of the spectrometer on the NaNiO2 antiferromagnet, the MgB2 superconductor, and the RbC60 conducting alkaline fulleride polymer. 相似文献
11.
Newly developed, high-performance, long-wave- and mid-wave-IR Dyson spectrometers offer a compact, low-distortion, broadband, imaging spectrometer design. The design is further accentuated when coupled to microbolometer array technology. This novel coupling allows radiometric and spectral measurements of high-temperature targets. It also serves to be unique since it allows for the system to be aligned warm. This eliminates the need for cryogenic temperature cycling. Proof of concept results are shown for a spectrometer with a 7.5 to 12.0 μm spectral range and approximately 20 nm per spectral band (~200 bands). Results presented in this Letter show performance for remote hot targets (>200 °C) using an engineering grade spectrometer and IR commercial lens assembly. 相似文献
12.
13.
Demonstration of a high-speed nonscanning imaging spectrometer 总被引:1,自引:0,他引:1
Descour MR Volin CE Dereniak EL Thome KJ Schumacher AB Wilson DW Maker PD 《Optics letters》1997,22(16):1271-1273
We report results from a field demonstration of a nonscanning high-speed imaging spectrometer [computed-tomography imaging spectrometer (CTIS)] capable of simultaneously recording spatial and spectral information about a rapidly changing scene. High-speed spectral imaging was demonstrated by collection of spectral and spatial snapshots of a missile in flight. This instrument is based on computed-tomography concepts and operates in the visible spectrum (430-710nm). Raw image data were recorded at video frame rate (30frames / s) and an integration time of 2ms. An iterative reconstruction of the spatial and spectral scene information from each raw image took 10s. We present representative missile spectral signatures from the missile firing. The accuracy of the high-speed spectrometer is demonstrated by comparison of extended-source static-scene spectra acquired by a nonimaging reference spectrometer with spectra acquired by use of CTIS imaging of the same static scenes. 相似文献
14.
We present a major improvement to the Fourier-transform infrared (FTIR) imaging technique brought about by replacement of the commonly used step-scan spectrometer with a rapid-scanning spectrometer. This advancement dramatically decreases the time required for data collection without decreasing the data quality. With this new instrumental setup, an imaging data set consisting of 64x64 spectra with a 4-cm (-1) spectral resolution over a 1360-cm (-1) spectral range can be collected in 34 s. As a practical example, we demonstrate what we believe to be the first application of FTIR imaging to the screening of adsorbates on the elements of a combinatorial library containing different supported catalyst materials in the same reactant feed. 相似文献
15.
A new method of measuring the intensity and state of polarization of optical radiation by means of the high resolution polarization interference imaging spectrometer (PIIS) is introduced and theoretically investigated in this paper. The error accuracy analysis is proposed, and it is proved that the system is very stable and precise in theory. In this new way, the polarized characteristics of light could be taken good use to analyze and distinguish objects in passive remote sensing with the PIIS, which means that the polarization interference imaging spectrometer now can be used not only as cameras and interferometers but also as polaristrobometers. 相似文献
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18.
A double-pass grating imaging spectrometer is proposed and demonstrated. The traditional entrance slit is replaced by a middle reflective slit, which is used as a spectral filter rather than a spatial filter. The light from the scene passes through the same dispersive grating twice. The full image of the scene can be obtained with a snapshot. Therefore, the stripe noise and image distortion caused by image mosaicking can be eliminated.Besides, the target is easier to be captured and focused, just like using a camera. This method can be used to obtain clearer spectral images of the scene conveniently and quickly. 相似文献
19.
L. Pappalardo J. de Sanoit C. Marchetta G. Pappalardo F. P. Romano F. Rizzo 《X射线光谱测定》2007,36(5):310-315
A new portable system that performs simultaneous particle induced x‐ray emission and x‐ray fluorescence analysis is described. It is based on the use of a 244Cm radioactive source as α‐particle and x‐ray emitter, coupled to a Si drift detector. Particular care has been devoted to the choice of the materials surrounding the source. X‐ray fluorescence spectra are presented, showing high detection efficiency for elements from Na (K lines) to Pb (L and M lines). The system can be used as a qualitative tool for ‘fingerprint’ analysis and, in some cases, as a quantitative one. Examples are presented and discussed. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
20.
A polarization interference imaging spectrometer (PIIS) for remote sensing is developed. Its operation principle and typical configuration are introduced. A polarization beam-splitter is its key component. The principle of calibration for the PIIS is introduced. The results of relative calibration for the PIIS are given. After the calibration, the responding uniformity of the detector of the PIIS to an expanded uniform light source is largely improved and the quality of the pictures obtained by the PIIS is obviously clear and accurate to the aims. Some applications and expectations of a PIIS are put forward. 相似文献