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991.
影响遥感相机成像质量的因素很多,为了提高遥感相机电子学成像质量,对核心元器件的信噪比、电路带宽、抑制高频信号干扰和暗电平箝位等影响因素进行了分析,提出了改进方法,并进行了实验验证。达到空间实际应用的要求。 相似文献
992.
Noriaki Kawaguchi Takayuki YanagidaYutaka Fujimoto Yuui YokotaKei Kamada Kentaro FukudaToshihisa Suyama Kenichi WatanabeAtsushi Yamazaki Valery ChaniAkira Yoshikawa 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,652(1):351-354
Thermal neutron imaging with Ce-doped LiCaAlF6 crystals has been performed. The prototype of the neutron imager using a Ce-doped LiCaAlF6 scintillating crystal and a position sensitive photomultiplier tube (PSPMT) which had 64 multi-channel anode was developed. The Ce-doped LiCaAlF6 single crystal was grown by the Czochralski method. A plate with dimensions of a diameter of 50×2 mm2 was cut from the grown crystal, polished, and optically coupled to PSPMT by silicone grease. The 252Cf source (<1 MBq) was sealed with 43 mm of polyethylene for neutron thermalization. Alphabet-shaped Cd pieces with a thickness of 2 mm were used as a mask for the thermal neutrons. After corrections for the pedestals and gain of each pixel, we successfully obtained two-dimensional neutron images using Ce-doped LiCaAlF6. 相似文献
993.
994.
Yoshihiko Kuroki 《Journal of the Society for Information Display》2012,20(10):566-574
The relationship between high frame rate and depth perception was investigated. Psychophysical experiments using moving random dot stereograms to study depth discrimination under several conditions showed that three‐dimensional motion images produced and displayed with a frame rate of 240 fps enable finer discrimination of depth for the viewer compared with frame rates of 120 or 60 fps. In addition, overall evaluations of natural three‐dimensional motion images by viewers confirmed that more natural motion and depth impressions were presented at 240 fps than at lower frame rates. Further, the results are discussed with reference to a recent theoretical model of the dynamic spatial frequency response of the camera/display system. 相似文献
995.
996.
Design feasibility of gamma camera without collimator based on specific arrangement of the detectors
《核技术(英文版)》2016,(4):67-73
In gamma camera and single-photon emission computerized tomography, the collimator removes most photons. Here, a gamma camera without collimator utilizes a specific arrangement of detectors. Instead of bending beams(like a lens) or directing beams(by parallel hole collimator), changes are created in detectors' field of view(FOV), so that each detector's FOV looks different from others. Simulation proved this theory, with 98 detectors(2 cm 9 1.41 cm) arranged in a zigzag manner for Monte Carlo simulation. A radioactive source with energy of140 ke V was situated on the detectors' faces. Sixty projections, each 3(0 –179) apart, were simulated by Monte Carlo N-Particle(MCNP) 4C code, rotating detectors around a radioactive point. The band containing the radioactive source is clearly visible in each projection.Counts obtained after simulation in different projections were reconstructed, and point source location emerged correctly. Simulation of gamma camera with zigzag arrangement of detectors and MCNP-4C code demonstrated that one could string the space and determine radioactive source by image reconstruction without using collimators, solely through these special detectors' distribution. 相似文献
997.
On the EAST tokamak, during whole off-axis LHCD (low hybrid current drive) limiter discharge, inverted sawteeth oscillations on the SXR (soft X-ray camera) signals appear continuously, and no positive sawtooth is observed. It is thought that this phenomenon is caused by the curvature pinch, though it could partly be explained by the electron temperature profile observed on the PHA (soft X-ray pulse height analyzer) system. The off-axis LHCD and Ohmic heating generate a non-monotonic q profile. According to the curvature pinch effect, this q profile leads to a special electron density profile that has a valley ring. The non-monotonic q profile and the special electron density profile lead to this interesting phenomenon. 相似文献
998.
J. Girardot M. Schneider L. Berthe V. Favier 《Journal of Materials Processing Technology》2013,213(10):1682-1691
Temperatures in the high pressure chamber of aircraft engines are continuously increasing to improve the engine efficiency. As a result, constitutive materials such as cobalt and nickel-base superalloys need to be thermally protected. The first protection is a ceramic thermal barrier coating (TBC) cast on all the hot gas-exposed structure. The second protection is provided by a cool air layer realized by the use of a thousand of drills on the parts where a cool air is flowing through. The laser drilling process is used to realize these holes at acute angles. It has been shown on coated single crystal nickel-base superalloy that the laser drilling process causes an interfacial cracking (also called delamination), detected by a cross section observation. The present work aims at characterizing interfacial cracking induced by laser drilling on coated cobalt-base super alloy. On the one hand, this work attempted to quantify the crack by several microscopic observations with regards to the most significant process parameters related as the angle beam. On the other hand, we studied the difference of the laser/ceramic and the laser/substrate interaction with real time observation by using a fast movie camera. 相似文献
999.
Radhakrishnan Nagarathnam Anandhan Rengasamy Rudresan Balasubramanian 《Journal of the science of food and agriculture》2010,90(1):97-105
BACKGROUND: Turmeric rhizome (Curcuma domestica Linn.) contains proteases and has proteolytic activity. Curcumin from turmeric rhizomes has been used for healing manu ailments, including cancer have been used for healing many ailments, including cancer. The purpose of this study was to purify turmeric protease and to research their biochemical characteristics. RESULTS: Cysteine protease from C. domestica has been purified to homogeneity using acetone precipitation followed by preparatory native polyacrylamide gel electrophoresis (PAGE). This protocol resulted in six fold purification with 28% final recovery. The purified turmeric protease showed a prominent single peak and band on high‐performance liquid chromatography and sodium dodecyl sulfate–PAGE, respectively, and an estimated molecular weight of 43 KDa, and exhibited optimal activity between 37 and 60 °C. The protease activity of the turmeric protease was significantly inhibited by iodoacetic acid. The turmeric protease had higher alanine and glutamate content and cleaved synthetic peptides N‐Cbz‐Ile‐Pro and N‐Cbz‐Phe‐Leu in a time‐dependent manner. Peptide mass fingerprint using matrix‐assisted laser desorption/ionization–time of flight mass spectroscopy revealed peptide matches to proteasome subunit alpha type 3 of Oryza sativa ssp. japonica (Rice). The turmeric protease showed antifungal activity at 10 µg mL?1 towards pathogens Pythium aphanidermatum, Trichoderma viride and Fusarium sp. CONCLUSION: Cysteine addition significantly activated turmeric protease. The protease inhibition test suggested that turmeric protease belonged to the cysteine type. The biochemical characteristics of turmeric protease described in this paper can provide useful information for potential end uses of turmeric protease for pharmaceutical industry applications such as therapeutics. Copyright © 2009 Society of Chemical Industry 相似文献
1000.
Many countries are increasing their research on monitoring technology to identify and systematically manage various domestic changes. In particular, the need for remote monitoring is increasing in response to climatic disasters, such as flooding, storms, and rising tides caused by global warming. We developed a smartphone-based environmental monitoring system that enables remote monitoring in any place and at any time. The overall system is composed of a 24-hour smartphone-based imaging system, a monitoring information management system to receive the monitoring information, and stereo image rectification software that provides lens distortion correction, geometric correction, and stereo matching of the monitoring images. The system was developed using the Samsung Galaxy S with the Android OS, as well as open source–based software and other hardware. It is easy to install, control remotely, and monitor the status of imaging devices. We assessed the accuracy of the micro-electro-mechanical system (MEMS) sensors of the smartphone to evaluate the applicability of our environmental monitoring system. The assessment was conducted via survey using metric cameras, a global positioning system receiver, a three-dimensional laser scanner and total station, geometric correction, and digital elevation models generated with camera internal elements, external elements, and ground control points. We demonstrated the effectiveness of the system, and showed that the accuracy of the MEMS sensor and camera calibration have a significant effect on image analysis. 相似文献