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41.
作者依据同一石英光轴的先后二次不同平面上的消光位,所造成的二平面相交,其交线必是光轴的原理,提出了用消光位法来测定石英光轴的空间方位。本方法只需测出每个石英颗粒在不同平面上的两个消光位及一个I轴的旋转角,便可作光轴投影图,从而求出石英光轴的空间方位。 相似文献
42.
针对天顶仪地面天文定位算法需要反复差值,计算繁琐的问题,文章将航天器姿态算法应用到天顶仪定位中来,详细研究了3种姿态算法,并为利用姿态算法实现定位给出了从姿态信息计算天顶仪光轴指向的新方法:建立了姿态算法的定位误差模型,结合过蒙特卡洛仿真,研究了姿态算法的定位精度并与原算法进行了比较;最后通过实际观测实验,实际分析了姿态算法和原算法在实验系统中的实际定位精度。结果表明:各姿态算法均能应用于天顶仪定位中,且精度高于原定位算法。 相似文献
43.
南美白对虾(Penaeus vannamei)视神经节和脑免疫细胞化学研究 总被引:2,自引:2,他引:0
应用抗脊椎动物5-羟色胺、神经肽Y、β-内啡肽、P物质、生长抑素、胰高血糖素、催乳素抗体和SABC免疫细胞化学方法,对南美白对虾视神经节和脑进行了免疫细胞化学研究。结果表明,前4种抗体呈现免疫阳性反应:5-羟色胺免疫阳性细胞分布于视神经节的视神经层、视外髓、视内髓和视端髓;前脑前中细胞群,中脑嗅叶内侧细胞群、嗅叶外侧细胞群以及前脑中部的前端神经髓质呈免疫阳性反应。神经肽Y免疫阳性细胞分布于视神经节的4个神经髓;前脑前中群细胞和前脑中部的前端神经髓质也呈阳性反应。P物质免疫阳性细胞位于前脑前中群。β-内啡肽免疫阳性细胞仅分布干后脑后侧群。4种免疫阳性物质特异性的分布模式,为其可能参与调节神经内分泌活动提供了形态学证据。 相似文献
44.
讨论了水下机器人远程通信光纤微缆的动力学问题,研究分析了在海洋层流条件下水下机器人的运动对光纤微缆张力的影响,在仿真分析的基础上提出了对光纤微缆收放系统的设计要求并给出了概念设计方案。 相似文献
45.
The effect of gauge length on axially incident P‐waves measured using fibre optic distributed vibration sensing
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Distributed vibration sensing, also known as distributed acoustic sensing, is a relatively new method for recording vertical seismic profile data using a fibre optic cable as the sensor. The signal obtained from such systems is a distributed measurement over a length of fibre referred to as the gauge length. In this paper, we show that gauge length selection is one of the most important acquisition parameters for a distributed vibration sensing survey. If the gauge length is too small, then the signal‐to‐noise ratio will be poor. If the gauge length is too large, resolution will be reduced and the shape of the wavelet will be distorted. The optimum gauge length, as derived here, is a function of the velocity and frequencies of the seismic waves being measured. If these attributes vary considerably over the depth of a survey, then the use of different gauge lengths is recommended. The significant increases in data quality resulting from the use of multiple gauge length values are demonstrated using field data. 相似文献
46.
47.
Zexia Qiu Hangzhou Wang Tao Li Hong Song Yuanqian Wu Tingting Yan Ying Chen 《海洋学报(英文版)》2021,40(3):134-141
An irradiance profile measurement approach and profiling system were developed to measure the solar irradiance profile of the Arctic sea ice using fiber optic spectrometry. The approach involved using a miniature spectrometer to sense light signals collected and transmitted from a fiber probe. The fiber probe was small, and could thus move freely in inclined bore holes drilled in sea ice with its optical entrance pointing upward. The input-output relationship of the system was analyzed and built. Influence factors that determined the system output were analyzed. A correctional system output approach was proposed to correct the influence of these factors, and to obtain the solar irradiance profile based on the measurements outputted by this system. The overall performance of the system was examined in two ice floes in the Arctic during the 9 th Chinese National Arctic Research Expedition. The measured solar irradiance profiles were in good agreement with those obtained using other commercially available oceanographic radiometers. The derived apparent optical properties of sea ice were comparable to those of similar sea ice measured by other optical instruments. 相似文献
48.
突发性地面塌陷对城市安全构成巨大威胁,掌握塌陷土体变形过程对地面塌陷事故的预测预报至关重要。基于分布式光频域反射(optical frequency domain
reflectometry,简称 OFDR )和粒子图像测速(particle image velocimetry,简称 PIV)技术,开展了地面塌陷模型试验,研究了塌陷过程中土体沉降的时空分布规律,并探究了不同应变感测光缆锚固方式对光纤监测结果的影响。结果表明:光纤应变监测曲线准确地反映了不同塌陷阶段上覆土体的变形状态,揭示了土体内部应变的演化机制;在光缆上设置圆片锚板,可以有效增强光缆与土体界面的耦合变形程度;在一定的埋置深度下,随着锚板尺寸的增大,光缆与土体间的变形协调性越好。研究结果显示,分布式应变传感技术在地面塌陷变形监测中具有较好的适用性,为该类地质灾害的早期识别提供了一种有力的工具。 相似文献
49.
1 INTRODUCTION Amines and peptides are important bioactive substance in crustaceans, and they function as hor- mones, neurotransmitters and neuromodulators. By far, bioactive substances that have been detected from nervous system of crustaceans include se… 相似文献
50.
《Marine Georesources & Geotechnology》2013,31(3-4):333-343
Taiwan Strait Tunnel (TST) will be an extra-long tunnel or tunnel-bridge complex, running over 150?km of seafloor geologic body with complicated topographic and geologic units. It is therefore necessary to measure and monitor the strain distribution along the TST. In this article, the Brillouin optical time-domain reflectometer (BOTDR), a newly developed strain measurement and monitoring technology, is introduced, and the feasibility of its application in the strain monitoring for TST is analyzed through the monitoring achievement with BOTDR of a tunnel located in Nanjing City, China. The results indicate that the BOTDR has many unique merits such as distributed measurement, long-distance, real-time, and resistibility for strain monitoring application in a tunnel such as TST. Finally, apreliminary scheme for BOTDR application in TST monitoring is proposed. 相似文献