极隙区极光粒子沉降对电离层影响的模拟研究   总被引：2，自引：0，他引：2       下载免费PDF全文

陈卓天  张北辰  杨惠根  刘瑞源 《极地研究》2006,18(3):166-174

利用一维自洽的时变极区电离层模型,研究极隙区极光粒子沉降对极区电离层F层电子密度影响的时变过程。假设一维时变电离层模型描述的磁流管中F层等离子体在对流作用下经过极隙区,随对流路径的不同,磁流管在极隙区经历的时间不同,以此考察极光粒子沉降作用下电离层随时间的演化过程。数值计算结果表明,当磁流管在极隙区停留的时间足够长,F层电子密度能显著增大。然而在磁流管经历极隙区实际时间较短的情况下,极隙区极光粒子沉降对F层电子密度的影响并不大。本文还给出了统计对流模型作用下磁流管在经历极隙区时,有沉降粒子作用和没有沉降粒子作用两种情况下,F层等离子体的时间变化过程的差异。  相似文献   

防腐高效溶样罐-ICP-MS测定海洋生物体中微量元素     

邱军  孙鹏  刘文琳  王晓婷  于卫松 《海洋科学》2020,44(6):131-136

为明确海洋生物体中微量元素的含量状况,开发了一种适合海洋生物体中微量元素准确测定的分析方法。研究采用防腐高效溶样罐对GBW08517（海带Saccharina japonica）与GBW08571（贻贝Mytilus coruscus Goyld）2种国内海洋生物标准物质进行2种不同前处理方法的消解实验,然后应用电感耦合等离子质谱仪（ICP-MS）测试了包括稀土元素在内的33个微量元素。实验结果表明,除个别元素外,测试结果均与标准值相符合,且前处理方法1消解的生物样品测试结果更加准确和稳定。使用防腐高效溶样罐优化了生物样品处理的消解方法,能有效去除生物样品中的有机基体,使ICP-MS充分发挥优势。与以往的消解方法相比,在生物消解中效果优于微波消解,前处理方法1还具有易操作、处理效率高、低试剂消耗、安全性强、避免样品污染等优点。  相似文献   

Effects of Na+/K+ ratio of groundwaters on the gill ion-transport enzyme activity, plasma osmolality and growth of Cynoglossus semilaevis juveniles     

Huizan Yang  Luqing Pan  Fawen Hu  Hongyu Liu 《中国海洋大学学报(英文版)》2008,7(4):447-452

The effects of environmental Na⁺/K⁺ ratio on the gill ion-transport enzyme activity, plasma osmolality and growth of Cynoglossus semilaevis juveniles were investigated. The results showed that, plasma osmolality was similar among flounder adapted to different Na⁺/K⁺ ratios of saline groundwaters (P>0.05), while the growth, gill Na⁺, K⁺-ATPase and HCO₃ ⁻-ATPase activities were affected by Na⁺/K⁺ ratio significantly (P<0.05). The gill Na⁺, K⁺-ATPase activity reached its maximum on day 3, then decreased gradually from day 3 to day 9 and remained constant from day 9 to day 15. The peak values of gill Na⁺, K⁺-ATPase activity were detected on day 3 for all Na⁺/K⁺ ratios of saline groundwaters, then the enzyme activities descended, and on day 9 the enzyme activities achieved steady state, and the gill HCO₃ ⁻-ATPase activity increased rapidly and achieved steady state after one day. During steady state, the gill Na⁺, K⁺-ATPase and HCO₃ ⁻-ATPase activity of Na⁺/K⁺ ratios 20 and 40 treatments were significantly higher than those in the control group (Na⁺/K⁺ ratio 27.5), while there were no significant differences between the Na⁺/K⁺ ratio 30 treatment and the control group; the gill Na⁺, K⁺-ATPase activity of Na⁺/K⁺ ratio 20 and 40 treatments were significantly higher than that for ratio 30 treatment, but there were no significant differences of gill HCO₃ ⁻-ATPase activity among these treatments. At the end of the 15-day experiment, the weight gain (%) and specific growth rate (SGR) of flounders maintained in seawater were significantly higher than those in groundwaters; significant differences also occurred among the treatments; Na⁺/K⁺ ratio 30 treatment had the highest values (33.7% and 1.94 respectively), which were significantly higher than those under Na⁺/K⁺ ratios 20 and 40 treatments. Therefore, for the saline groundwater used in this experiment, it is suggested that the Na⁺/K⁺ ratio be adjusted to approximately 30, i.e., as close to that of natural seawater as possible in the culture of flounder.  相似文献   

Effects of Na^＋/K^＋ Ratio of Groundwaters on the Gill Ion-Transport Enzyme Activity, Plasma Osmolality and Growth of Cynoglossus semilaevis Juveniles     

YANG Huizan  PAN Luqing  HU Fawen  LIU Hongyu 《中国海洋大学学报(英文版)》2008,7(4)

The effects of environmental Na /K ratio on the gill ion-transport enzyme activity,plasma osmolality and growth ofCynoglossus semi/aevis juveniles were investigated.The results showed that,plasma osmolality was similar among flounder adaptedto different Na /K ratios of saline groundwaters (P>0.05),while the growth,gill Na ,K -ATPase and HCO,3'--ATPase activities wereaffected by Na /K ratio significantly (P<0.05).The gill Na ,K -ATPase activity reached its maximum on day 3,then decreasedgradually from day 3 to day 9 and remained constant from day 9 to day 15.The peak values of gill Na ,K -ATPase activity weredetected on day 3 for all Na /K ratios of saline groundwaters,then the enzyme activities descended,and on day 9 the enzyme activi-ties achieved steady state,and the gill HCO,3--ATPase activity increased rapidly and achieved steady state after one day.Duringsteady state,the gill Na ,K -ATPase and HCO,3--ATPase activity of Na /K ratios 20 and 40 treatments were significantly higherthan those in the control group (Na /K ratio 27.5),while there were no significant differences between the Na /K ratio 30 treatmentand the control group; the gill Na ,K -ATPase activity of Na /K ratio 20 and 40 treatments were significantly higher than that forratio 30 treatment,but there were no significant differences of gill HCO3-ATPase activity among these treatments.At the end of the15-day experiment,the weight gain (%) and specific growth rate (SGR) of flounders maintained in seawater were significantly higherthan those in groundwaters; significant differences also occurred among the treatments; Na /K ratio 30 treatment had the highestvalues (33.7% and 1.94 respectively),which were significantly higher than those under Na /K ratios 20 and 40 treatments.There-fore,for the saline groundwater used in this experiment,it is suggested that the Na /K ratio be adjusted to approximately 30,I.e.,asclose to that of natural seawater as possible in the culture of flounder.  相似文献   

ICPAES法同时测定钛铁矿中钾钠钙镁钡锶锌          下载免费PDF全文

王卿  回寒星  周长祥  吕学勤 《山东国土资源》2013,29(10)

采用HClHNO3HF HClO4,HClHNO3HF H2SO4敞口和HClHNO3HFHClO4,HClHNO3HF H2SO4微波消解4种方法溶矿,利用电感耦合等离子体发射光谱（ICPAES）测定,建立了钛铁矿中钾、钠、钙、镁、钡、锶、锌等元素的同时测定方法。对电感耦合等离子体发射光谱仪测定的最佳仪器条件及分析谱线进行了选择,并对钛、铁基体的影响、溶矿提取酸度以及溶矿残渣进行了研究。实验结果表明：采用HClHNO3HF HClO4敞口溶矿,具有检出限低、灵敏度高,操作简便、快速等突出优点。该方法测定值与推荐值基本吻合,分析方法的精密度满足《地质矿产实验室测试质量管理规范》的要求。  相似文献   

电感耦合等离子体发射光谱仪在钡铍等多元素同时测定中的应用          下载免费PDF全文

王卿 《山东国土资源》2005,21(9):52-54

采用多种酸溶矿（HCl-HNO3-HClO—HF）,利用电感耦合等离子体发射光谱仪,建立了适用于土壤、水系沉积物等样品中钡、铍等19种元素的同时测定方法。并用国家标准物质验证了方法的准确度和精密度,其相对误差均小于10％,样品12次测定的RSD为0．9％～5％。  相似文献   

基于雷电预警技术的风电设施防雷技术     

李强  王婷婷  李楠 《南京气象学院学报》2012,4(6):512-516

风力发电技术迅猛发展,单机发电量不断增加,风电机组高度已增加到上百米,风电机组叶片遭受雷击风险也随之加大.通过雷电损害实例分析风机叶片雷击灾害机理,分析雷电击中风机叶片的形成和发展过程,总结大型风机叶片的特点和风电场的环境因素,以大气电场仪的预警数据为基础,结合前沿的等离子体防雷新技术,针对风力发电机的具体情况进行改进,提出实现风电叶片主动避雷的防雷技术构想,探索一种实现风电机组设备避雷的新思路.  相似文献   

Laboratory light-scattering measurements with Titan's aerosols analogues produced by a dusty plasma     

E. Hadamcik  J.-B. Renard  G. Cernogora  C. Szopa 《Planetary and Space Science》2009,57(13):1631-1641

The chemistry leading to the formation of solid aerosols (tholins) in Titan's atmosphere is simulated by a capacitively coupled plasma in a N₂-CH₄ gas mixture. The solid grains are produced in volume directly in the gas phase and studied ex-situ by SEM imaging and by light scattering on clouds of particles. The scattered light properties depend on the physical properties of the particles (morphologies, size distribution), as well as on the phase angle and the wavelength of the light. The particles may be aggregated or agglomerated grains. The grains size distribution is studied as a function of plasma parameters such as initial methane concentration introduced into the discharge, gas flow, absorbed RF power and plasma duration. The average grain size increases when the amount of CH₄ increases, when the gas flow decreases, and when the plasma duration increases up to a limit for each production condition.For all the samples, the absorption decreases with increasing wavelength in the visible domain. As usually found for irregular particles, the polarization phase curves have a bell-shaped positive branch and a shallow negative branch. The maximum of polarization (P_max) increases when the average grain size decreases (sub-μm-sized grains). To obtain P_max values within the range of those measured in Titan's atmosphere; the average grains diameter has to be smaller than 100 nm, in agreement with the space observations results. In the light-scattering experiment, the size of the agglomerates in the clouds is in the 40-80 μm range in equivalent diameter. As a consequence P_max increases with decreasing wavelength due to the increasing absorption, in agreement with observations of Titan from outside the atmosphere.  相似文献   

On the origin of energetic particles in the foreshock region of the Earth’s bow shock     

G. N. Kichigin 《Astronomy Letters》2009,35(4):261-269

We consider the processes related to the formation of the so-called foreshock region upstream of the Earth’s bow shock. We suggest a model based on the surfing of pick-up ions in the bow shock front in terms of which the ion acceleration mechanism in the front can be explained. We ascertain the physical conditions under which the accelerated ions lie upstream of the shock front and determine the direction of motion of the energetic ions. We conclude that it is this population of energetic ions (longitudinal beams) that plays a major role in forming the ion foreshock boundary.  相似文献   

NI 493.5 nm谱线Stark加宽估算闪电放电等离子体电子密度   总被引：1，自引：1，他引：0       下载免费PDF全文

郭逸潇  袁萍  瞿海燕 《高原气象》2009,28(3):675-679

依据青海地区一次闪电回击过程的光谱,分析了NI 493.5 nm谱线的Stark加宽效应,得到加宽在1.5～2.5 nm左右,通道不同位置的谱线两边显示出稍有一些不对称性;结合NI 493.5 nm线Stark加宽的半经验参数,对通道不同位置的电子密度进行了定量计算,得到平均电子密度是1.657×1017 cm-2,并与各位置处用Hα谱线半宽得到的电子密度进行了比较,证实用NI 493.5 nm和Hα谱线半宽得到的电子密度基本一致,由NI谱线的Stark加宽估算闪电等离子体电子密度是一种实用可信的方法.数据分析表明:随着通道位置的升高,电子密度略呈减小趋势;电子密度与谱线半宽近似呈线性关系.  相似文献