scholarly journals Research progress on micro-thrust and micro-impulse measurement technology of PPT

2019 ◽  
Author(s):  
Xinru Du ◽  
Jianjun Wu ◽  
Yu Zhang ◽  
Jian Li ◽  
Sheng Tan ◽  
...  
2021 ◽  
Author(s):  
Yongchao Zhang ◽  
Tieli Zhang ◽  
Xiaoxue Liu ◽  
Shuo Jin ◽  
Xiujian Zhang ◽  
...  

2015 ◽  
Vol 52 (4) ◽  
pp. 040004
Author(s):  
师中华 Shi Zhonghua ◽  
杨宝喜 Yang Baoxi ◽  
魏张帆 Wei Zhangfan ◽  
李璟 Li Jing ◽  
黄惠杰 Huang Huijie

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhenxu Bai ◽  
Zhongan Zhao ◽  
Yaoyao Qi ◽  
Jie Ding ◽  
Sensen Li ◽  
...  

A narrow-linewidth laser with excellent temporal coherence is an important light source for microphysics, space detection, and high-precision measurement. An ultranarrow-linewidth output with a linewidth as narrow as subhertz has been generated with a theoretical coherence length over millions of kilometers. Traditional grating spectrum measurement technology has a wide wavelength scanning range and an extended dynamic range, but the spectral resolution can only reach the gigahertz level. The spectral resolution of a high-precision Fabry–Pérot interferometer can only reach the megahertz level. With the continuous improvement of laser coherence, the requirements for laser linewidth measurement technology are increasing, which also promotes the rapid development of narrow-linewidth lasers and their applications. In this article, narrow-linewidth measurement methods and their research progress are reviewed to provide a reference for researchers engaged in the development, measurement, and applications of narrow-linewidth lasers.


Agriculture ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 462
Author(s):  
Jizhang Wang ◽  
Yun Zhang ◽  
Rongrong Gu

Three-dimensional (3D) plant canopy structure analysis is an important part of plant phenotype studies. To promote the development of plant canopy structure measurement based on 3D reconstruction, we reviewed the latest research progress achieved using visual sensors to measure the 3D plant canopy structure from four aspects, including the principles of 3D plant measurement technologies, the corresponding instruments and specifications of different visual sensors, the methods of plant canopy structure extraction based on 3D reconstruction, and the conclusion and promise of plant canopy measurement technology. In the current research phase on 3D structural plant canopy measurement techniques, the leading algorithms of every step for plant canopy structure measurement based on 3D reconstruction are introduced. Finally, future prospects for a standard phenotypical analytical method, rapid reconstruction, and precision optimization are described.


2018 ◽  
Vol 55 (3) ◽  
pp. 030008
Author(s):  
席建普 Xi Jianpu ◽  
李彬 Li Bin ◽  
任东旭 Ren Dongxu ◽  
赵则祥 Zhao Zexiang

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