X射线荧光光谱分析方法标准化的进展     

楼蔓藤 《岩矿测试》2002,21(1):42-48

简述了X射线荧光光谱分析方法标准化的进展，包括其意义与历史回顾、标准现状、不足与建议。主要参考文献33篇。  相似文献   

电感耦合等离子体原子发射光谱法测定硅铁中微量元素   总被引：6，自引：1，他引：6  

刘先国  方金东 《岩矿测试》2002,21(1):63-65

应用电感耦合等离子体发射光谱法对硅铁中微量元素的测定进行了研究，采用基体匹配法消除了大量基体的干扰，选择了最佳激发条件，样品的加标回收率在97％－107％。方法用美国硅铁标样分析验证，测定结果与标准值吻合较好，各元素8次测定的RSD％＜7％。  相似文献   

电感耦合等离子体质谱技术进展 及在地学研究中的应用          下载免费PDF全文

黄长玉 《甘肃地质》2008,17(1):92-95

介绍了ICP-MS技术特点及最新发展起来的碰撞室和动态反应池技术,并对该技术在地学中的应用范围进行了总结。  相似文献   

油页岩及其脱油残渣的矿物学研究     

王玉洁  李殿超  肖国拾  张桢干 《世界地质》2008,27(4)

利用吉林农安和桦甸、广东茂名、海南长昌以及黑龙江达连河等5个产地的油页岩样品进行脱油残渣的烧制和不同条件下的成瓷条件实验,通过XRD、XRF分析及烧失率的变化,初步获得了5个产地油页岩的化学成分、矿物含量、废渣成分及烧瓷后的矿物成分等.结果表明:不同油页岩中黏土矿物的种类差异在不同程度上会影响油页岩的含油率.  相似文献   

腾格里沙漠昂格尔图湖记录的988 AD以来的古气候变化          下载免费PDF全文

曹志宏  安成邦  尹丽颖  段阜涛  郝盛吞  周爱锋 《干旱区地理》2018,41(6):1251-1259

通过对腾格里沙漠东南部昂格尔图湖岩芯AGE15A的粒度、碳酸盐的百分含量和主要化学元素等多项沉积学气候代用指标及精确定年的综合分析,重建了该区域988 AD以来的古气候变化序列。结果表明：988 AD以来的研究区的气候环境的演化过程与我国西北西风区古气候变化基本一致,呈现"冷湿-暖干"交替变化的特征,但在时间上存在一定的延迟。具体表现为：988~1383 AD,昂格尔图湖由洼地发育成小型湖泊,化学风化作用弱,湖区气候环境整体偏冷湿,期间出现几次暖波动;1383~1560 AD,研究区处在中世纪暖期,为温暖、干旱的气候特征,此时湖泊扩张,湖中水生植物生长茂盛,呼吸作用增强,造成大量的碳酸盐沉淀,最高值达到8.16%;1560~1700 AD,致使气候在昂格尔图湖形成之后出现最寒冷的时期,降水增加,气候湿冷,此时段与小冰期最盛期相对应;1700 AD之后,温度开始上升,气候回暖,在1900 AD左右达到最甚,此时沉积物中碳酸盐的百分含量也达到最大值,为10.15%,此期间湖泊继续扩张,出现几次气候冷波动。基于我国古代文献重建的历史时期气候变化基本不包括沙漠地区,所以本文利用湖相沉积记录来反演腾格里沙漠昂格尔图湖历史时期的气候环境演变,对中国沙漠研究有着重要参考价值,同时也为中国西北历史时期的气候重建提供科学依据。  相似文献   

Where are the X-ray quasi-periodic oscillations in active galaxies?     

S. Vaughan  P. Uttley 《Monthly notices of the Royal Astronomical Society》2005,362(1):235-244

In this paper, we address the question of whether existing X-ray observations of Seyfert galaxies are sufficiently sensitive to detect quasi-periodic oscillations (QPOs) similar to those observed in the X-ray variations of Galactic black holes (GBHs). We use data from XMM–Newton and simulated data based on the best Rossi X-ray Timing Explorer ( RXTE ) long-term monitoring light curves to show that if X-ray QPOs are present in Seyfert X-ray light curves – with similar shapes and strengths to those observed in GBHs, but at lower frequencies commensurate with their larger black hole masses – they would be exceedingly difficult to detect. Our results offer a simple explanation for the present lack of QPO detections in Seyferts. We discuss the improvements in telescope size and monitoring patterns needed to make QPO detections feasible. The most efficient type of future observatory for searching for X-ray QPOs in active Galactic nuclei (AGN) is an X-ray All-Sky Monitor (ASM). A sufficiently sensitive ASM would be ideally suited to detect low-frequency QPOs in nearby AGN. The detection of AGN QPOs would strengthen the AGN–GBH connection, and could serve as powerful diagnostics of the black hole mass and the structure of the X-ray emitting region in AGN.  相似文献   

Entropy amplification from energy feedback in simulated galaxy groups and clusters     

S. Borgani  A. Finoguenov  S. T. Kay  T. J. Ponman  V. Springel  P. Tozzi  G. M. Voit 《Monthly notices of the Royal Astronomical Society》2005,361(1):233-243

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Development of the HEFT and NuSTAR focusing telescopes     

Fiona A. Harrison  Finn E. Christensen  William Craig  Charles Hailey  Wayne Baumgartner  C. M. H. Chen  James Chonko  W. Rick Cook  Jason Koglin  Kristin-Kruse Madsen  Michael Pivavoroff  Steven Boggs  David Smith 《Experimental Astronomy》2005,20(1-3):131-137

Hard X-ray/soft gamma-ray astrophysics is on the verge of a major advance with the practical realization of technologies capable of efficiently focusing X-rays above 10 keV. Hard X-ray focusing telescopes can achieve orders of magnitude improvements in sensitivity compared to the instruments based on coded apertures and collimated detectors that have traditionally been employed in this energy band. Compact focal planes enable high-performance detectors with good spectral resolution to be employed in efficient, low-background configurations. We have developed multilayer coated grazing incidence optics and solid state Cadmium Zinc Telluride focal plane systems for the High Energy Focusing Telescope (HEFT) balloon-borne experiment, and for the Nuclear Spectroscopic Telescope Array (NuSTAR) Small Explorer satellite. In this paper we describe the technologies, telescope designs, and performance of both experiments.  相似文献   

Study of the fast X-ray transient XTE J1901+014 based on INTEGRAL,RXTE, and ROSAT data     

D. I. Karasev  A. A. Lutovinov  S. A. Grebenev 《Astronomy Letters》2007,33(3):159-167

The source XTE J1901+014 discovered by the RXTE observatory during an intense outburst of hard radiation and classified as a fast X-ray transient is studied. The source’s spectral characteristics in the quiescent state have been investigated for the first time both in the soft X-ray energy range (3–20 keV) based on ROSAT and RXTE data and in the hard energy range (>20 keV) based on INTEGRAL data. A timing analysis of the source’s properties has revealed weak nonperiodic bursts of activity on time scales of several tens of seconds and two intense (～0.5–1 Crab) outbursts more than several hundred seconds in duration. Certain assumptions about the nature of the object under study are made.  相似文献   

Photon Spectroscopy with Imaging X-Ray Instruments     

B. J. Labonte  K. P. Reardon 《Solar physics》2007,240(2):387-401

Individual X-ray photons in the keV energy range produce hundreds of photoelectrons in a single pixel of a CCD array detector. The number of photoelectrons produced is a linear function of the photon energy, allowing the measurement of spectral information with an imaging detector system. Most solar X-ray telescopes, such as Yohkoh/SXT and Hinode/XRT, use CCD detectors in an integrating mode and are designed to make temperature estimates from multiband filter photometry. We show how such instruments can be used in a new way to perform a limited type of this photon spectroscopy. By measuring the variance in intensity of a series of repeated images through a single filter of an X-ray source, the mean energy per detected photon can be determined. This energy is related to the underlying coronal spectrum, and hence it can be used to deduce the mean plasma temperature. We apply this technique to data from the Yohkoh Soft X-Ray Telescope and compare the temperatures obtained with this technique with the temperatures derived using the standard filter ratio method for a postflare loop system. Given the large dynamic range of the soft X-ray flux observed from the Sun, we describe the requirements for a future instrument that would be better suited to performing photon spectroscopy. B.J. Labonte deceased 24 October 2005.  相似文献