In order to change the current disadvantages of traditional large equipment maintenance concept, this article plans to apply the technical method of prognostics and health management to optimize equipment maintenance ...
In order to change the current disadvantages of traditional large equipment maintenance concept, this article plans to apply the technical method of prognostics and health management to optimize equipment maintenance strategy and develop large equipment maintenance system. Combined with the maintenance procedures of various phases in life cycle, it concluded the formulation methods of maintenance program and implement plans of maintenance work. In the meantime, it takes account into the example of the dredger power system of the Waterway Bureau to establish the auxiliary platform of ship maintenance system in life cycle.
With the extension of the service time of the structure and the worse service temperature conditions, the drift problem of hightemperature strain gauges gradually becomes prominent. This research aims to address the i...
ISBN:
(数字)9781839539275
With the extension of the service time of the structure and the worse service temperature conditions, the drift problem of hightemperature strain gauges gradually becomes prominent. This research aims to address the issue of the drift of measurement results because of the performance degradation of high-temperature strain gauges, and investigate the drift law under different temperatures considering complex service environments. In this paper, a combination of experimental research and theoretical analysis is utilized to design and conduct the accelerated performance degradation test on high-temperature strain gauges. Based on the result of the test, an accelerated performance degradation model is developed using the Wiener process and Arrhenius model. Finally, estimation curves for the average value and percentile value of the performance parameters of the hightemperature strain gauges are obtained, which demonstrates that the established accelerated performance degradation model can reasonably describe the degradation law. Additionally, the established accelerated performance degradation model enables effective analysis and compensation of gauge drift at any temperature.
Accurate nuclear data provide an essential foundation for advances in a wide range of fields, including nuclear energy, nuclear safety and security, safeguards, nuclear medicine, and planetary and space exploration. I...
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Accurate nuclear data provide an essential foundation for advances in a wide range of fields, including nuclear energy, nuclear safety and security, safeguards, nuclear medicine, and planetary and space exploration. In these and other critical domains, outdated, imprecise, and incomplete nuclear data can hinder progress, limit precision, and compromise safety. Similar nuclear data needs are shared by many applications, thus prioritizing these needs is especially important and urgently needed. Many levels of analysis are required to prepare nuclear measurements for employment in end-user applications. Because research expertise is typically limited to one level, collaboration across organizations and international borders is essential. This perspective piece provides the latest advances in nuclear data for applications and describes an outlook for both near- and long-term progress in the field.
The reduction in transistor dimensions and advancements in chip integration have led to a dramatic increase in the heat flux of chip. Advanced heat dissipation technology has become the pivotal in ensuring the normal ...
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Alkaline metal-air batteries are advantageous in high voltage, low cost, and high safety. However, metal anodes are heavily eroded in strong alkaline electrolytes, causing serious side reactions including dendrite gro...
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Alkaline metal-air batteries are advantageous in high voltage, low cost, and high safety. However, metal anodes are heavily eroded in strong alkaline electrolytes, causing serious side reactions including dendrite growth, passivation, and hydrogen evolution. To address this limitation, we successfully synthesized an organic N-heterocycle compound (NHCC) to serve as an alternative anode. This compound not only exhibits remarkable stability but also possesses a low redox potential (−1.04 V vs. Hg/HgO) in alkaline environments. To effectively complement the low redox potential of the NHCC anode, we designed a dual-salt highly concentrated electrolyte (4.0 M KOH+10.0 M KCF 3 SO 3 ). This electrolyte expands the electrochemical stability window to 2.3 V through the robust interaction between the O atom in H 2 O molecule with the K + of KCF 3 SO 3 (H−O⋅⋅⋅KCF 3 SO 3 ). We further demonstrated the K + uptaken/extraction storage mechanism of NHCC anodes. Consequently, the alkaline aqueous NHCC anode-air batteries delivers a high battery voltage of 1.6 V, high-rate performance (101.9 mAh g −1 at 100 A g −1 ) and long cycle ability (30,000 cycles). Our work offers a molecular engineering strategy for superior organic anode materials and develops a novel double superconcentrated conductive salt electrolyte for the construction of high-rate, long-cycle alkaline aqueous organic anode-air batteries.
Generative AI (GAI) has emerged as a significant advancement in artificial intelligence, renowned for its language and image generation capabilities. This paper presents "AIGenerated Everything" (AIGX), a co...
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In the severe high-temperature environment caused by aerodynamic heating, the vibrational excitation, dissociation and ionization of gas may successively occur, which are known as real gas effects. Under the real gas ...
In the severe high-temperature environment caused by aerodynamic heating, the vibrational excitation, dissociation and ionization of gas may successively occur, which are known as real gas effects. Under the real gas effects, the thermodynamic properties of gas vary drastically and significantly influence the performances of the active thermal protection system of hypersonic vehicles, especially in the case with coolant outflow, for example transpiration cooling. This paper numerically investigates the transpiration cooling performance with the consideration of the interaction between coolant outflow and hypersonic flow under the real gas effects. The mathematical models and coupled numerical strategy are firstly validated by experimental data, then the influences of real gas effects on the transpiration cooling of a wedged leading edge (WLE) are studied under a flight Mach number range from 8 to 12 and a flight height of 40 km. The analysis and discussions of the numerical results reveal some important phenomena and demonstrate the need to consider real gas effects.
In order to investigate the runoff pollutant control effects by different types of permeable paving systems (PPS), Porous asphalt (PA), Porous concrete (PC), Cement brick (CTB), Ceramic brick (CCB), Sand base brick (S...
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作者：
BARTON, GGFELDMAN, SMr. Sidney Feldman formerly with the Naval Applied Science Laboratory
is presently with the Radiation Division of the Naval Surface Weapons Center White Oak Silver Spring Maryland. He planned and supervised laboratory experiments of many optical systems for fleet evaluation several of his designs now being standard in the fleet. He received his BA degree in Physics from Brooklyn College in 1941 and majored in Physics at the Brooklyn Polytechnic Institute. His professional memberships include the Optical Society of America American Association for the Advancement of Science and The Scientific Research Society of North America. He was the recipient of the Naval Ordnance Development Award in 1945 the Superior Achievement Award in 1957 the Quality Salary Increase Award in 1965 the Superior Accomplishment Award in 1967 1970 and 1979. Additionally he has been granted patents for a relamping tool for searchlights (1962) a lamp positioning mechanism for searchlights (1963) a daylnight digital sextant (1973) a portable sextant-computer system (1974) and with Mr. George Barton the remote-controlled LLLTV camera-sextant (1976) the automatic passive LLLTV-rangefinder (1977) and a patent disclosure for the omnidirectional transceiver (1980). Mr. George G. Barton has been employed by the Naval Research Laboratory
Washington D. C. for the past ten years in the scientific and military application design engineering and fabrication of low light level TV camera systems. He was previously associated with the Smithsonian Institution and Northwestern University in the application of TV technology in astronomical investigations. He attended New York University Newark College of Engineering and New Mexico State University where he majored in Physical Optics. Presently he is with his own company BISMARC Inc. Harker's Island N.C. where he is involved principally in the design manufacture and marketing of sonar systems such as the unique VIDISEA fishscope research and development in electrooptic systems an
During periods of radio silence under Emission Control, communication depends on the slow ship-to-ship, manual-visual, 8-10 wpm Morse code signaling shutter searchlight employing the ac 1000-watt incandescent or the a...
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During periods of radio silence under Emission Control, communication depends on the slow ship-to-ship, manual-visual, 8-10 wpm Morse code signaling shutter searchlight employing the ac 1000-watt incandescent or the ac 1000-watt compact arc mercury-xenon lamp. These sources can be replaced by the dc compact arc xenon lamp to provide longer daylight ranges and highspeed (100 wpm teletype, 150 wpm Morse code, voice, etc.) communication since this source has superior brightness and the facility of considerably more rapid modulation. The excessive weight and size of the ac-dc power convertor and modulating circuitry which had prevented use of the dc xenon lamp have been overcome by developments in solid state electronics such as the rapid, high current, simmer-flash, 100 to one light output xenon lamp pulsing using the reliable, uncomplicated, low-cost silicon controlled rectifier shunt switch which could eliminate the mechanical signaling shutter. laboratory and sea evaluations have proved the feasibility of and provided the long daylight high-speed optical communication ranges that could be attained from operation of the dc 1000-watt and 2200-watt xenon lamps at the focus of 12-inch, 18-inch searchlights and in the Fresnel lens omni-directional beacon which a command ship uses to signal all ships in a task force at once. With these advances, optical communication provides the highspeed capability of radio communication, particularly, also, with the new omnidirectional transceiver.
We study a Shimura variety attached to a unitary similitude group of a skew-Hermitian form over a totally indefinite quaternion algebra over a totally real number field. We give a necessary and sufficient condition fo...
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