- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Solidification Effect on the Microstructure and Mechanism of Laser Solid Forming Produced Flame-Resistant Ti-35V-15Cr Alloy
摘要： The block and thin-wall Ti-35V-15Cr samples were built by laser solid forming (LSF). The extremely sensitive thermal behavior condition in LSF results in significantly different microstructure. The microstructure of LSF-produced block sample mainly consists of epitaxial columnar dendritic grains, while that of the thin-wall sample is mainly composed of near-equiaxed grains together with sub-grains formed in the near-equiaxed grains.
关键词： sub-grains,Laser solid forming,temperature gradient,Ti-35V-15Cr,thermal cycling
更新于2025-09-23 15:19:57
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Laser Technology to Guide Rainfall to a Particular Region
摘要： Rain bearing clouds can be effectively guided to a specific region during monsoon or other seasons so that rainfall shall be equitably distributed without creating drought situations. Lasers sent into the lower troposphere region with intensities sufficient to create a temperature gradient and thereby creating a low pressure area in a specific region can invite rain bearing clouds to a region opposite to where heat is generated by laser effect, so as to bring convective rainfall during a season.
关键词： Troposphere,Laser effect,Low pressure,Convective rainfall,Equitably,Temperature gradient
更新于2025-09-23 15:19:57
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Observation of water droplets oscillation due to laser induced Marangoni convection
摘要： In this paper, using experimental characterizations, we explore the motion of water droplets suspended in mineral oil under exposure of a focused continuous wave (CW) fiber laser beam. The laser beam exposure heats the surrounding oil medium as well. The temperature gradient generates thermocapillary (or Marangoni) convection flows. This approach uses infrared laser-induced thermocapillary-driven flow for manipulation of droplets in the range of 10 to 30 μm in diameter. The droplets are trapped in the convection flow and travel with thermocapillary convection flow (depending on the droplet sizes) along the streamline with high speed. This motion is observed at a certain critical power of the laser. The behavior of a droplet in response to thermally induced convection can be considered. we also examined the oscillatory behavior of the droplet on the xy plane. As expected, oscillation frequency/amplitude are linearly correlated to the droplet size.
关键词： Convection,Fiber laser,Marangoni force,Manipulation,Oscillation frequency,Thermocapillary,Temperature gradient
更新于2025-09-16 10:30:52
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Thermo-Mechanical Analysis of Laser Additive Manufacturing for Metals
摘要： The aim of this study is to develop a finite element analysis technique to characterize the distributions of temperature and stress in the process of multilayer deposition of metallic powders by laser additive manufacturing (LAM). Simulation results indicate the residual normal stress in the laser moving direction is greater than that in other directions due to a larger temperature gradient, and it increases with number of deposited layers. Highly residual stresses are present in the LAM build and at the base nearby the interface between the build and base.
关键词： laser additive manufacturing,temperature gradient,finite element analysis,metal,residual stress
更新于2025-09-11 14:15:04
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Variable location channels to improve efficiency and precision for direct ? <i>T</i> <sub/><i>e</i> </sub> measurements and high spatial resolution <i>T</i> <sub/><i>e</i> </sub> -profile measurements using electron cyclotron emission
摘要： Electron cyclotron emission (ECE) diagnostics that use variable location channels based on yttrium iron garnet (YIG) bandpass filters improve the precision and the efficiency of measurements of electron temperature (Te) profiles and fluctuations (δTe). These variable frequency filters were substituted for fixed frequency filters in the intermediate frequency section to achieve the required higher resolution over a target radial range, just before the experiment. Here, we present the proof-of-principle for high temporal resolution measurement of the electron temperature gradient, via real-time slewing of a YIG filter for relocation of an ECE channel during a long pulse. The key component is the application of YIG tunable filters with their narrow bandwidth and capability for a high slew rate of their center frequency. This application permits fast relocation of the ECE channels for direct measurement of the gradient and close spacing of channels to investigate the magnetic island’s dynamic behavior.
关键词： Electron cyclotron emission,YIG bandpass filters,electron temperature gradient,high spatial resolution
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Budapest (2018.7.1-2018.7.5)] 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Influence of temperature gradient on charge accumulation phenomena of GIS spacer under DC field
摘要： DC-GIS is used in HVDC systems because of its excellent insulation performance. However, when DC voltage is applied to DC-GIS, charges are accumulated on the surface of the insulator. This leads to decrease the breakdown voltage. Therefore, understanding charge accumulation phenomena is significant to make more reliable HVDC systems. In this paper, we focused on effects of the temperature gradient on the spacer to charge accumulation phenomena. We developed the experimental device which makes thermal distribution on an insulated model spacer and we measured charge distributions on it under temperature gradient. Also, numerical simulation was conducted to understand this phenomenon. We concluded that when temperature gradient is generated in the spacer, charging is more widely distributed.
关键词： temperature gradient,charge accumulation,GIS,spacer
更新于2025-09-10 09:29:36
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Growth of Structurally Perfect Diamond Single Crystals at High Pressures and Temperatures. Review
摘要： The investigations performed at high pressures and high temperatures (HTHP crystallization) have permitted clarifying the mechanism of phase transformations and carbon transport in solvent metals for diamond growth and elaborating methods for growing large-size structurally perfect diamond single crystals of types Ib, IIa, and IIb. The findings have provided the basis for the process of production of diamonds for applications in electronics, laser technology, precision machining operations, well drilling tools. The use of a large-volume six-punch high pressure apparatus makes it possible to grow diamond single crystals with a higher efficiency. It is estimated that this apparatus is capable of producing annually at least 1 mln carats of structurally perfect crystals of required types for various applications.
关键词： diamond single crystals,growth systems,temperature gradient method,high pressure apparatus
更新于2025-09-10 09:29:36
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EXPERIMENTAL LEVELLING AT THE INTERFACE OF OPTICAL ENVIRONMENTS
摘要： The article discusses the problems of refraction and its impact on levelling at the interface of optical environments. It describes the in?uence of a vertical refraction and shows the results of investigating the e?ect of the refraction in the course of levelling at the interface of optical environments. The results of the experiment were obtained by levelling through the building of the National Technical Library in Prague Dejvice.
关键词： refraction,levelling,temperature gradient,digital thermometer
更新于2025-09-09 09:28:46