加拿大对饮水中Ca、Cd、Co、Cr、Cu、Mg、Ni、Pb和Zn含量两次全国调查所取得的成果     

J.C.梅朗热  C.夏利富  K.S.萨布拉马安  明世乾 《地理科学进展》1985,4(2):64-66

加拿大对饮用水中的微量元素Cd、Co、Cr、Cu、Ni、Pb和Zn进行了两次全国性调查。调查中包括Ca和Mg。为了检验水净化和水分配过程中水的质量,对70个城镇的天然水,净化水和自来水进行了取样分析。采用两种方法:石墨炉原子化器和吡咯烷二硫代氨基甲酸铵(APDC)萃取法对Pb、Cr和Cd进行了直接分析,並对所取得的结果加以对比研究。结果表明,微量元素分析一般並不因为有固体微粒而受到影响。水中查出的有毒元毒的浓度比允许的最大值低得多。在水净化和分配给用户过程中,这些元素的浓度除Cu以外几乎都没有增加。  相似文献   

水在非均质雪中的流动     

S·C·COLBECK  迟国彬 《干旱区地理》1985,(2)

一、引言研究和预测积雪覆盖地域上径流的形成是十分必要的。前人已对雪层中融水和雨水的运动问题做过细致的研究。本文给出在含有冰层和流槽的积雪中水的流动模式。对于雪特性空间变化的一切设计,它都是适用的。  相似文献   

半无限空间中SH波被空腔和刚性包体所散射(英文)     

曾心传  A.S.Cakmak 《大地测量与地球动力学》1985,(3)

根据波尔近似,借助于波动积分方程,近似求解半无限弹性空间中平面SH波由圆形空腔和刚性包体所散射的问题。获得了空腔表面上的散射位移、作用于被包体上的剪应力、半空间表面形变以及远场位移的近似公式。在数值计算中,ka(k=波数,a=空腔或被包体的半径)取为1.0,γ(SH波的入射角,从垂向方向起算)取为π/4。  相似文献   

TRAVEL TO SOUTHERN SINKIANG     

S. Ting 《地理学报》1948,(1)

This paper records my geological and geomorphological observations enroute from Urumuchito Aksu. Leaving Urumuchi on August Ist, we passed through the graben trough of Davan,followed the course of Bayan Ho to Toksun in the Turfan Basin. Glaci-fluvial deposits were seen in the valley of Bayanho at 980m. above the sea. Toksun city has an elevation read from  相似文献   

Simulation Study on High Energy Cosmic Electron Detection by Shower Image     

Rong Xu Jin Chang S. Torii K. Kasahara T. Tamura K. Yoshida 《天体物理学报》2007,7(6):839-844

Many projects have recently been carried out and proposed for observing high energy electrons since it is realized that cosmic ray electrons are very important when studying the dark matter particles and the acceleration mechanism of cosmic rays. An imaging calorimeter, BETS （Balloon-borne Electron Telescope with Scintillator fiber）, has been developed for this purpose. Using pattern analysis of the shower development, the electrons can be selected from those primary cosmic ray proton events with flux heights one-tenth that of the electrons. The Monte-Carlo simulation is indispensable for the instrument design, the signal trigger and the data analysis. We present different shower simulation codes and compare the simulation results with the beam test and the flight data of BETS. We conclude that the code FLUKA2002 gives the most consistent results with the experimental data.  相似文献   

Simulation Study on High Energy Cosmic Electron Detection by Shower Image     

S.Torii  K.Kasahara  T.Tamura  K.Yoshida 《中国天文和天体物理学报》2007,7(6):839-844

Many projects have recently been carried out and proposed for observing high energy electrons since it is realized that cosmic ray electrons are very important when study-ing the dark matter particles and the acceleration mechanism of cosmic rays. An imaging calorimeter,BETS (Balloon-borne Electron Telescope with Scintillator fiber),has been de-veloped for this purpose. Using pattern analysis of the shower development,the electrons can be selected from those primary cosmic ray proton events with flux heights one-tenth that of the electrons. The Monte-Carlo simulation is indispensable for the instrument design,the sig-nal trigger and the data analysis. We present different shower simulation codes and compare the simulation results with the beam test and the flight data of BETS. We conclude that the code FLUKA2002 gives the most consistent results with the experimental data.  相似文献   

Distribution, Use Pattern and Prospects for Conservation of Medicinal Shrubs in Uttaranchal State, India   总被引：1，自引：0，他引：1  

Bhupendra S. Adhikari Mani M. Babu Prem L. Saklani Gopal S. Rawat 《山地科学学报》2007,4(2):155-180

The present paper gives an insight into the distribution and use pattern of medicinal shrubs in Uttaranchal State. A total of 222 medicinal and aromatic shrub species have been appended based on secondary information. Euphorbiaceae, Rosaceae, Verbenaceae, and Fabaceae have the highest repre- sentatives of medicinal shrubs. Twenty one families had one species each in medicinal use. Verbenaceae and Euphorbiaceae in the sub-tropical region, Rosaceae in the temperate region, and Ericaceae and Rosaceae in the sub-alpine and alpine regions, respectively, had the highest representatives of medicinal shrubs. The distribution of medicinal shrubs was 42 % in sub-tropical, 29 % in warm temperate, 13 % in cool temperate, 9 % in sub-alpine and 7 % in the alpine region. Of the total species, 70 medicinal shrubs were native to the Himalayas and 22 native to Himalayan region including other Hima- layan countries. The most frequently used plant parts for various ailments were leaves (31 %) and roots (23 %). Most shrubs are being used for the diseases, viz. skin diseases, dysentery, cough, fever, wounds, and rheumatism. The present paper will help in the execution of strategies for promotion and cultivation of medicinal shrubs in Uttaranchal State.  相似文献   

The 21st International Geological Congress, Norden 1960     

Henning Sφrensen 《《幕》》2007,30(2):125-130

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A possible precessing nozzle and the Lense-Thirring effect in blazar 3C 454.3     

Shan-Jie Qian  S. Britzen  A. Witzel  T. P. Krichbaum  Heng-Qian Gan  Long Gao 《天文和天体物理学研究(英文版)》2014,(3):249-274

The kinematics of superluminal components in blazar 3C 454.3 are studied.Nine components are included:superluminal knots R1,R2,R3,R4,A,B,C and D(from Britzen et al.2013) and C4(from Pauliny-Toth 1998).We find that their kinematics derived from VLBI observations can be consistently interpreted in terms of a jet precession scenario with a period of about 14.5 yr.We discuss the model fits of their trajectory,distance from the core and apparent velocity.We show that the bulk Lorentz factor(in the range 4 to 15) derived for these components does not have any dependence on the phase of the precession(or position angle for ejection).The LenseThirring effect is assumed to interpret the precession of the jet nozzle.The results obtained for blazar 3C 454.3 are only suggestive.They are not unique and have yet to be tested,but they might be useful for understanding the kinematics of superluminal components in blazars and for disentangling different mechanisms and factors.  相似文献   

东印度洋水体输运的季节变化及相关盐度变化     

L. A. A. N. Wickramasinghe  王卫强  刘雨  M. K. Abeyratne  W. C. Hemamali  K. B. S. S. J. Ekanayake 《南京气象学院学报》2020,12(4):472-482

利用20年（1992-2012年）的ECCO2模式模拟数据,主要研究了东印度洋（EIO）水体输运的季节变化.在EIO选取3个断面,分别为赤道、80°E和6°N.研究结果表明,跨赤道和80°E的季节输运主体部分大致相补偿.跨赤道的大部分水体输运局限在上层100 m,80°E的水体输运具有复杂结构,与显著的季风流、Wyrtki Jets（WJs）、赤道潜流（EUC）等有关.6°N上层水体净输运较小,但存在较强的边界流和相对较弱的内区流.纬向流的显著变化发生在80°E.在季风盛行季节,由于WJs减弱,赤道附近的水体输运以西向的梯度流为主,上层100 m的其余区域则主要受季风流控制.同样,由于EUC减弱,西向的梯度流与次表层东向的EUC之间也存在转换.在季风转换季节,季风流减弱,WJs与EUC分别在上层100 m和次表层占主导地位.此外,本研究还讨论了与季风流、WJs和EUC相关的盐水和暖水交换,有助于了解研究区域内温度和盐度的水平和垂直结构.  相似文献