- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Application and Extension of Vertical Intensity Lower-Mode in Methods for Target Depth-Resolution with a Single-Vector Sensor
摘要： In this paper, based on the reactive component of the vertical intensity, the method for target depth resolution has been improved. In the previous existing research results, using the reactive component of vertical intensity, the research objects for target depth resolution in shallow water, can only be the targets whose frequencies can only excite the ?rst two normal modes, and the depth of targets whose frequencies excite more than two normal modes cannot be correctly identi?ed. The basic idea of the improved method is to classify targets on the foundation of the lower-mode correlation quantity of the vertical intensity. Based on the improved method, we can realize depth resolution of the targets whose frequency can excite the ?rst three normal modes so as to effectively expand the working band useful for target depth resolution. Finally, we can realize the three-dimensional target depth resolution so as to distinguish the aerial, surface and underwater targets. The feasibility of the algorithm is veri?ed by simulation and experimental data processing.
关键词： ?rst three normal modes,improved method,lower-mode correlation quantity,Monte Carlo,depth resolution
更新于2025-09-23 15:21:21
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Multispectral incoherent holography based on measurement of differential wavefront curvature
摘要： We propose a technique of multispectral incoherent holography. The differential wavefront curvature is measured, and the principle of Fourier transform spectrometry is applied to provide a set of spectral components of three-dimensional images and continuous spectra for spatially incoherent, polychromatic objects. This paper presents the mathematical formulation of the principle and the experimental results. Three-dimensional imaging properties are investigated based on an analytical impulse response function. The experimental and theoretical results agree well.
关键词： Impulse response function,Multispectral imaging,Depth resolution,3D imaging property,Spectroscopy,Incoherent holography
更新于2025-09-19 17:13:59
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Shallow sampling by multi-shot laser ablation and its application within U-Pb zircon geochronology
摘要： The interaction of incident laser radiation and sample substrate is complex and difficult to predict. Natural zircons are often both structurally and chemically heterogeneous in 3-dimensional space. Encountering growth-related, structural micro-heterogeneities, inclusions and chemical complexities is almost inevitable during a static ablation of several tens of seconds. A multi-shot approach to laser ablation described here implements a minimal sample exposure time to incident laser radiation by applying multiple 1 Hz shots to a single sample location in delayed succession. This process can be conceptualised as a “slowing down” of a high-frequency (5-20 Hz) static laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis until each laser pulse is distinct albeit transient. The ability to integrate and collate signal pulses for a small number of consecutive laser shots, as opposed to continuously pulsing the laser, produces precise age determinations (~1% reproducibility, 2σ level) on small sample volumes (698 ± 22 μm3 on 91500 zircon standard). The multi-shot LA-ICP-MS protocol employed here significantly reduces the effect of ‘downhole’ fractionation as the resultant craters are extremely shallow (as shallow as 0.56 ± 0.02 μm on 91500 zircon standard) and maintain an aspect ratio of <<1. Further benefits include a reduced probability of thermally induced effects (e.g., substrate melting), plasma loading, and the potential for signal mixing (with depth) in a heterogeneous sample.
关键词： multi-shot LA-ICP-MS,depth resolution,LIEF,sub-micron sampling,downhole fractionation,Low sample volume
更新于2025-09-16 10:30:52