中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
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Academician Wen-Rui Hu - Eminent Pioneer and Prominent Leader of Microgravity Science in China 期刊论文  OAI收割
MICROGRAVITY SCIENCE AND TECHNOLOGY, 2, 2022, 卷号: 34, 页码: 19
作者:  
Li K(李凯);  Zhao JF(赵建福);  Kang Q(康琦);  Wang SF(王双峰);  Kang Q(康琦)
  |  收藏  |  浏览/下载:32/0  |  提交时间:2022/10/23
食用蔬菜能吸收和积累微塑料 期刊论文  OAI收割
科学通报, 2019, 卷号: 64, 期号: 9, 页码: 928-934
作者:  
李连祯;  周倩;  尹娜;  涂晨;  骆永明
  |  收藏  |  浏览/下载:150/0  |  提交时间:2020/06/17
微塑料  生菜  聚苯乙烯微球  吸收  积累  健康风险  microplastics  lettuce  polystyrene microbeads  uptake  accumulation  human health risk  Microplastic (MP, 100 nm-5 mm) may present an attributable risk to ecosystem and human health, and its pollution has become a global environmental concern. Despite a wealth of information on the accumulation of MPs in aquatic species, there is no information on the uptake and accumulation of MPs by higher plants. Terrestrial edible plants are directly exposed to MPs when agricultural soil was applied with organic manure, sewage sludge as fertilizer or plastic mulching. In this paper, the uptake of two sizes of polystyrene (PS) microbeads (0.2 and 1.0 mum) and then their distribution and migration in an edible plant lettuce were firstly investigated based on laboratory experiments. We used fluorescent markers to track PS microbeads in plant tissues and found fluorescence to be a sensitive and reliable detection method. Sections from untreated control lettuce showed no autofluorescence. When roots were treated with fluorescently labeled PS microbeads, the microbeads could be identified by its fluorescence. Our main study investigated the uptake of 0.2 mum beads, as few luminescence signals were observed in lettuce roots for 1.0 mum beads in our experiment. We observed that 0.2 mum fluorescent microbeads were extracellularly trapped in the root cap mucilage (which is a highly hydrated polysaccharide) and a dark green tip (which was typical of lettuce roots exposed to label PS beads) was usually visible to the naked eye. Confocal images revealed that the PS luminescence signals were mainly located in the vascular system and on the cell walls of the cortex tissue of the roots, indicated that the beads passed through the intercellular space via the apoplastic transport system. Once inside the central cylinder, the 0.2 mum PS beads were transferred from the roots to the stems and leaves via the vascular system following the transpiration stream. We also observed that the PS beads adhered to one another and self-assembled systematically into grape-like and (chain) string-like clusters in the intercellular space of the root and stem vascular tissue of lettuce plant. In contrast to the root and stem, PS beads were dispersed in the leaf tissue. Here, for the first time we provide evidence of the adherence, uptake, accumulation, and translocation of submicrometer MPs within an edible plant. Our findings highlight the previously underappreciated human exposure pathway to MPs through the consumption of contaminated crops and emphasize the need for new management strategies to control the release of MPs waste products into the terrestrial environment. Ultimately, the potential impacts of low range sized MPs on food safety of crop plants and human health need to be urgently considered.  
Interferometric Imaging Radar Altimeter On Board Chinese Tiangong-2 Space Laboratory 会议论文  OAI收割
Kyoto, JAPAN, NOV 06-09, 2018
作者:  
Zhang, Yunhua;  Shi, Xiaojin;  Wang, Hongjian;  Tan, Yueyin;  Zhai, Wenshuai
  |  收藏  |  浏览/下载:60/0  |  提交时间:2019/03/05
Ground experiments on a liquid bridge facility for TG-2 space laboratory 会议论文  OAI收割
65th International Astronautical Congress 2014: Our World Needs Space, IAC 2014, Toronto, ON, Canada, September 29, 2014 - October 3, 2014
作者:  
Duan L(段俐);  Kang Q(康琦)
收藏  |  浏览/下载:65/0  |  提交时间:2017/05/27
Support technique of ultra thin mirror in space optics (EI CONFERENCE) 会议论文  OAI收割
2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, November 2, 2005 - November 5, 2005, Xian, China
作者:  
Ren J.-Y.;  Gao M.-H.
收藏  |  浏览/下载:37/0  |  提交时间:2013/03/25
With the development of space optical system  the technique of ultra thin mirror come forth and is paid more attention because of less difficulty in machining  low cost  lightweight  no disassembly during detecting and maintaining. The key technique takes advantage of deformation of ultra thin mirror as the influence of environment to adjust the surface figure. Its accuracy meets requirement. An analysis method is based on finite element analysis (FEA)  and many items  including the amount of support points  the way of arrangement  the optimum design of support component are studied. The finite element method was used to analyze the mirror and some different mirror support schemes. The principal aim of the mirror analysis is to get numbers of support points and the ways of the support. There are three schemes including 12-6-1  12-8-1 and 16-8-1 models. Deformation of deadweight is calculated under the three conditions. The way of 16-8-1 is more suitable than the designs of other two. The support subassembly is amended to meet with the mirror surface RMS in the range of 30m. Deformation of the mirror with support structure has been calculated. The result is 16.52nm  lower than a quarter of the wavelength  which indicates the feasibility of the support scheme applied to mirror. Theoretical result for the best way of support is presented. The result of analysis shows that requirement surface figure could be met through adjusting support points. It predicts feasibility of the support technique and provides theoretical value for active adjustment in the laboratory. At present  support and adjusting experiment of ultra thin mirror is being carried on.  
Integrated mach-zehnder micro-interferometer for gas trace remote sensing (EI CONFERENCE) 会议论文  OAI收割
ICO20: Remote Sensing and Infrared Devices and Systems, August 21, 2005 - August 26, 2005, Changchun, China
作者:  
Wang P.
收藏  |  浏览/下载:47/0  |  提交时间:2013/03/25
The realisation process and the preliminary tests on the performances of an integrated Mach-Zehnder Interferometer on LiNbO3 (Lithium Niobate) substrate is presented. The microsystem has been obtained by using medium mass Ion Implantation on X-cut Lithium Niobate crystals. The interferometer is formed by integrated optical channel waveguides: the phase shift between the two optical paths has been obtained  1mm 2 cross section and weights a few grams. The power consumption is in the milliwatt range. In the present work results obtained in the spectral window (0.4m-1.1m) will be presented. The performance of the device  without moving parts  evaluated on standard radiation sources  by applying a suitable electric field. The whole device is 60mm long  demonstrates that a spectral resolution better than 0.3nm can be obtained on 400nm spectral windows. The Micro-interferometer has been tested in laboratory with a calibrated cell containing NO2 gas and has demonstrated sensitivity in the ppb range if suitable optical paths are used. Its reduced dimensions and weights make these micro-systems ideal for a wide range of applications  has a 0.57times  spanning from Space Technology  Earth observation for Environment monitoring  to Safety and Security applications.  
A new method of image reconstruction with high resolution in X-ray coded aperture imaging (EI CONFERENCE) 会议论文  OAI收割
Laser-Generated, Synchrotron, and Other Laboratory X-Ray and EUV Sources, Optics, and Applications II, August 2, 2005 - August 4, 2005, San Diego, CA, United states
作者:  
Sun Y.
收藏  |  浏览/下载:24/0  |  提交时间:2013/03/25
In the processing diagnosis of the inertia confinement fusion (ICF)  the ring coded aperture imaging technique is applied in order to gain high space and time resolutions simultaneously. The key of acquiring high spatial resolution is how to obtain a point spread function of an imaging system. The common method is the firsthand projection method which is an approximate one. The x-ray diffraction effect is neglected in the method  so the resolution of reconstructed image is decreased. We have derived the point spread function (PSF) of the ring coded aperture from scalar diffraction theory. And the Wiener filter is fabricated on the basis of the PSF. In National Key Laboratory of Laser Fusion  at China Academy of Engineering Physics  the imaging experiment on the diagnosis of ICF is completed using the ring coded aperture plate with inner diameter d1 = 250m and outer diameter d2 = 260m . The obtained coded image is processed by the Wiener filter which diffractive effect is considered. The processed results have shown that resolution and modulation contrast of acquired image are evidently better than the results obtained by the firsthand projection method.