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环境水样中金属元素的分析通常采用电感耦合等离子体质谱法(ICP-MS),检出限低、线性范围宽,但仍存在使用功率高、耗气量大、分析成本高以及不适用于现场分析等不足。本文为降低金属元素分析成本,建立了微波等离子体炬(MPT)与有机质谱耦合的方式检测水样中钙离子的新方法。详细探究了载气流速和维持气流速对钙离子响应信号的影响,方法检出限为224.56 ng/L,相对标准偏差(RSD)为1.2%~9.8%,加标回收率在86.3%~110.4%之间。本方法无需样品预处理,分析速度快、灵敏度和精确度高,为环境水样中金属离子的测定提供了新途径,有望应用于金属离子的实时在线分析。 相似文献
114.
环境样品中有机物分析的前处理技术 总被引:4,自引:0,他引:4
综述了顶空法、吹脱-捕集法、固相萃取、微波萃取、超临界流体萃取技术在环境样品前处理中的应用现状并比较了这种几样品处理方法的优缺点。 相似文献
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王保志 《成都信息工程学院学报》1996,(4)
在对线性两端口网络S参量分析的基础上,给出了利用史密斯圆图设计微波晶体管放大器的一般方法。并与解析设计法进行了比较 相似文献
117.
Anthony L. Peratt 《Astrophysics and Space Science》1995,227(1-2):3-11
The year 1996 marks the Centennial Celebration of the founding of Plasma Astrophysics and Cosmology; its origins may be traced to the seminal research first published by Kristian Birkeland in 1896. This special workshop issue reports on advances in issues of importance to the plasma universe; topics as timely as when first raised a century ago. 相似文献
118.
李庆 《成都信息工程学院学报》1989,(4)
本文讨论了在小信号下混频器内部参数Rs,Cj及混频器所有可能端口(ω_m=ω_o+ω_p) 对总的混频器噪声系数的影响、推导出了噪声系数公式、得出了镜像匹配及抑制下的噪声表达式。 相似文献
119.
S. Schiller G. M. Tino P. Gill C. Salomon U. Sterr E. Peik A. Nevsky A. Görlitz D. Svehla G. Ferrari N. Poli L. Lusanna H. Klein H. Margolis P. Lemonde P. Laurent G. Santarelli A. Clairon W. Ertmer E. Rasel J. Müller L. Iorio C. Lämmerzahl H. Dittus E. Gill M. Rothacher F. Flechner U. Schreiber V. Flambaum Wei-Tou Ni Liang Liu Xuzong Chen Jingbiao Chen Kelin Gao L. Cacciapuoti R. Holzwarth M. P. Heß W. Schäfer 《Experimental Astronomy》2009,23(2):573-610
The Einstein Gravity Explorer mission (EGE) is devoted to a precise measurement of the properties of space-time using atomic
clocks. It tests one of the most fundamental predictions of Einstein’s Theory of General Relativity, the gravitational redshift,
and thereby searches for hints of quantum effects in gravity, exploring one of the most important and challenging frontiers
in fundamental physics. The primary mission goal is the measurement of the gravitational redshift with an accuracy up to a
factor 104 higher than the best current result. The mission is based on a satellite carrying cold atom-based clocks. The payload includes
a cesium microwave clock (PHARAO), an optical clock, a femtosecond frequency comb, as well as precise microwave time transfer
systems between space and ground. The tick rates of the clocks are continuously compared with each other, and nearly continuously
with clocks on earth, during the course of the 3-year mission. The highly elliptic orbit of the satellite is optimized for
the scientific goals, providing a large variation in the gravitational potential between perigee and apogee. Besides the fundamental
physics results, as secondary goals EGE will establish a global reference frame for the Earth’s gravitational potential and
will allow a new approach to mapping Earth’s gravity field with very high spatial resolution. The mission was proposed as
a class-M mission to ESA’s Cosmic Vision Program 2015–2025.
相似文献
S. SchillerEmail: |
120.
Kebiao Mao Ying Ma Lang Xia Xinyi Shen Zhiwen Sun Tianjue He Guanhua Zhou 《中国地理科学(英文版)》2014,24(5):599-606
It has been observed that low temperature, rainfall, snowfall, frost have never occurred over the past 50 years in the southern China, and weather in this area is very complex, so the monitoring equipments are few. Optical and thermal infrared remote sensing is influenced much by clouds, so the passive microwave Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) data are the best choice to monitor and analyze the development of disaster. In order to improve estimation accuracy, the dynamic learn- ing neural network was used to retrieve snow depth. The difference of brightness temperatures of TB18.7v and TB36.sv, TBI8.7H and TB36.sH, TB23,sv and TB89v, TBz3.8H and TB89H are made as four main input nodes and the snow depth is the only one output node of neural network. The mean and the standard deviation of retrieval errors are about 4.8 cm and 6.7 cm relative to the test data of ground measurements. The application analysis indicated that the neural network can be utilized to monitor the change of snow intensity distribution through passive microwave data in the complex weather of the southern China. 相似文献