Resonant Heating of Ions by Parallel Propagating Alfvén Waves in Solar Coronal Holes     

Tian-Xi Zhang  Jing-Xiu Wang  Chi-Jie Xiao National Astronomical Observatories  Chinese Academy of Sciences  Beijing  Center for Space Plasma  Aeronomic Research  The University of Alabama in Huntsville  Huntsville  AL  USA   《中国天文和天体物理学报》2005,(3)

Resonant heating of H, O+5, and Mg+9 by parallel propagating ion cyclotron Alfven waves in solar coronal holes at a heliocentric distance is studied using the heating rate derived from the quasilinear theory. It is shown that the particle-AlfVen-wave interaction is a significant microscopic process. The temperatures of the ions are rapidly increased up to the observed order in only microseconds, which implies that simply inserting the quasilinear heating rate into the fluid/MHD energy equation to calculate the radial dependence of ion temperatures may cause errors as the time scales do not match. Different species ions are heated by Alfven waves with a power law spectrum in approximately a mass order. To heat O+5 over Mg+9 as measured by the Ultraviolet Coronagraph Spectrometer (UVCS) in the solar coronal hole at a region ≥1.9.R, the energy density of Alfven waves with a frequency close to the O+5-cyclotron frequency must be at least double of that at the Mg+9-cyclotron frequency. With an appropriate wa  相似文献   

原生金刚石的可能新源岩     

沈瑞锦  刘德镒 《湖南地质》1999,(Z1)

国际上衡量一个国家的工业化程度，往往用工业上金刚石的消耗量作为衡量标准之一。我国金刚石资源严重不足，半个世纪以来，金刚石原生矿的寻找未取得重大进展，究其原因，恐怕与认识和思维观点的局限有关。若换一种观念去思索问题，也许会走上寻找金刚石原生矿的希望之路...  相似文献   

Arsenic species in weathering mine tailings and biogenic solids at the Lava Cap Mine Superfund Site,Nevada City,CA     

Foster AL  Ashley RP  Rytuba JJ 《Geochemical transactions》2011,12(1):1

Background  

A realistic estimation of the health risk of human exposure to solid-phase arsenic (As) derived from historic mining operations is a major challenge to redevelopment of California's famed "Mother Lode" region. Arsenic, a known carcinogen, occurs in multiple solid forms that vary in bioaccessibility. X-ray absorption fine-structure spectroscopy (XAFS) was used to identify and quantify the forms of As in mine wastes and biogenic solids at the Lava Cap Mine Superfund (LCMS) site, a historic "Mother Lode" gold mine. Principal component analysis (PCA) was used to assess variance within water chemistry, solids chemistry, and XAFS spectral datasets. Linear combination, least-squares fits constrained in part by PCA results were then used to quantify arsenic speciation in XAFS spectra of tailings and biogenic solids.  相似文献   

中周期面波在核监测中的重要性     

Levs.  AL 宋臣田 《地震科技情报》1996,(4):4-4

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第十二届国际沉积学大会简介     

刘德镒 《地质论评》1987,33(1):104-104

第十二届国际沉积学大会于1986年8月24日—30日在澳大利亚首都堪培拉国立大学(Australian Na-tional University,Canberra)举行。大会由国际沉积学家协会、澳大利亚地质学会、新西兰地质学会和地质地球物理矿产局联合主办。与会代表约900多人,分别来自澳大利亚、新西兰、中国、日本、英国、法国、  相似文献   

Applications of a total dissolved gas pressure probe in ground water studies   总被引：2，自引：0，他引：2  

Manning AH  Solomon DK  Sheldon AL 《Ground water》2003,41(4):440-448

Measurements of dissolved gases have numerous applications in ground water hydrology, and it is now possible to measure the total dissolved gas pressure in situ using a probe. Dissolved gas pressure is measured by submerging a headspace volume with a gas-permeable membrane, allowing dissolved gases in the water to equilibrate with gases in the headspace, then measuring the pressure in the headspace with a pressure transducer. Total dissolved gas pressure (TGP) probes have many potential uses in ground water studies employing dissolved gases, including: (1) determining approximate excess air levels, which may provide information about the time and location of recharge; (2) screening wells for air contamination, which can compromise the accuracy of dissolved gas tracer techniques: (3) detecting a trapped gas phase, which can significantly reduce hydraulic conductivity and impede the transport of dissolved solutes and gases; (4) enabling the use of gas-filled passive diffusion samplers for determining accurate dissolved gas concentrations; and (5) determining relative concentrations of CH4 and CO2 when they are known to be highly abundant. Although TGP probes designed for surface water have been available for several years, TGP probes suitable for ground water applications have only recently become available. Herein we present what are, to our knowledge, the first reported ground water dissolved gas data collected using a TGP probe. We also explain the basic operating principles of these probes and discuss the potential applications listed.  相似文献   

西澳利亚州阿盖尔（AKI）钾镁煌斑岩岩筒中含金刚石的橄榄岩捕虏体     

贾克.  AL  汤葵 《国土资源信息化》1991,(4):6-7

  相似文献   

陕西宁强海泡石及其成因的初步研究     

刘德镒 《矿物学报》1986,(3)

陕西宁强海泡石赋存于二叠系泥灰岩、Ca-Mg质页岩和粘土中。本区海泡石呈纤 维状或纤维集合体。由于有高含量的水,折光率较低,平均为1.508,干涉色为灰色。该矿物的粉 晶衍射图谱最强线有12.17,7.47,6.70,4.51和4.32A。本文亦描述了该矿物的差热分析,热 重、化学分析和红外资料。 本区海泡石作为化学沉积物,形成于边缘海或内陆海中。特别是在铝浓度低,氧化硅浓度高,镁浓度高和pH为碱性的环境中更易形成。  相似文献   

对《坡缕石-海泡石的产状、成因和用途》一书的评介     

刘德镒 《地质论评》1986,32(4):412-413

辛格(A.Singer)和盖伦(E.Galan)编辑的《坡缕石-海泡石的产状、成因和用途,(Palygorskite-sepiolite Occurrences,Genesis and Uses。以下简称《海抱石》)一书,已于1984年11月由美国纽约科学出版有限公司出版了。这是一本论文集,共收入18篇文章,加上书后的附编、作者索引和主题索引共约21万字。这是一部迄今为止世界上论述坡缕石和海泡石的最全的专著。它不仅以大量篇幅描述了世界上各种产  相似文献   

Geochemical processes during five years of aquifer storage recovery   总被引：4，自引：0，他引：4  

Herczeg AL  Rattray KJ  Dillon PJ  Pavelic P  Barry KE 《Ground water》2004,42(3):438-445

A key factor in the long-term viability of aquifer storage recovery (ASR) is the extent of mineral solution interaction between two dissimilar water types and consequent impact on water quality and aquifer stability. We collected geochemical and isotopic data from three observation wells located 25, 65, and 325 m from an injection well at an experimental ASR site located in a karstic, confined carbonate aquifer in South Australia. The experiment involved five major injection cycles of a total of 2.5 x 10(5) m3 of storm water (total dissolved solids [TDS] approximately 150 mg/L) into the brackish (TDS approximately 2400 mg/L) aquifer. Approximately 60% of the mixture was pumped out during the fifth year of the experiment. The major effect on water quality within a 25 m radius of the injection well following injection of storm water was carbonate dissolution (35 +/- 6 g of CaCO3 dissolved/m3 of aquifer) and sulfide mineral oxidation (50 +/- 10 g as FeS2/m3 after one injection). < 0.005% of the total aquifer carbonate matrix was dissolved during each injection event, and approximately 0.2% of the total reduced sulfur. Increasing amounts of ambient ground water was entrained into the injected mixture during each of the storage periods. High 14C(DIC) activities and slightly more negative delta13C(DIC) values measured immediately after injection events show that substantial CO2(aq) is produced by oxidation of organic matter associated with injectant. There were no detectable geochemical reactions while pumping during the recovery phase in the fifth year of the experiment.  相似文献