Ethnic results of the 1979 Soviet census     

Shabad T 《Soviet geography》1980,21(7):440-488

This article is based on summary results concerning ethnic composition in the USSR according to the 1979 census. "These results...have been rearranged... to reflect not only the ethnic composition of the USSR and of its republics over time (1959, 1970, 1979), but also shifts in the distribution of particular ethnic groups. Furthermore, ethnic groups are discussed in a regional sequence. In combination with the migration tables based on previous results of the 1979 census...some conclusions can be drawn concerning the ethnic makeup of migrants among republics."  相似文献   

Results of TV imaging of Phobos (Experiment VSK-Fregat)     

Avanesov G  Zhukov B  Ziman YA  Kostenko V  Kuzmin A  Murav'ev V  Fedotov V  Bonev B  Mishev D  Petkov D  Krumov A  Simeonov S  Boycheva V  Uzunov YU  Weide GG  Halmann D  Pössel W  Head J  Murchie S  Schkuratov YuG  Berghänel R  Danz M  Mangoldt T  Pihan U  Smith B 《Planetary and Space Science》1991,39(1-2):281-295

From February to March 1989 the Phobos 2 spacecraft took 37 TV images of Phobos at a distance of 190-1100 km. These images complement Mariner-9 and Viking data by providing higher-resolution coverage of a large region West of the crater Stickney (40-160 degrees W) and by providing disk-resolved measurements of surface brightness at a greater range of wavelengths and additional phase angles. These images have supported updated mapping and characterization of large craters and grooves, and have provided additional observations of craters' and grooves' bright rims. Variations in surface visible/near-infrared color ratio of almost a factor of 2 have been recognized; these variations appear to be associated with the ejecta of specific large impact craters. Updated determinations of satellite mass and volume allow calculation of a more accurate value of bulk density, 1.90 +/- 0.1 g cm-3. This is significantly lower than the density of meteoritic analogs to Phobos' surface, suggesting a porous interior perhaps containing interstitial ice.  相似文献   

铂族新矿物——峨眉矿OsAs_2的初步研究   总被引：2，自引：0，他引：2  

任迎新  胡钦德  徐进高 《地质学报》1978,52(2)

峨眉矿发现于四川某地铜镍硫化物型铂矿床中。化学成分为锇的二砷化物,化学式为OsAs_2。斜方晶系,晶胞参数为a=5.409,b=6.167,c=3.021。空间群Pnnm或Pnn2。研究结果确定,这是一个铂族金属新矿物。以产地所在省境内的名山——峨眉山命名,称为峨眉矿(Omeiite)。  相似文献   

Remediation and restoration of metal-contaminated sites： Concepts and appfications to mining areas     

Domy C. Adriano Hyo T. Chon Sally L. Brown Rosanna Ginocchio 《中国地球化学学报》2006,25(B08):45-46

Metals, including heavy metals and metalloids, are a common group of environmental contaminants. Their sources in the environment are geogenic or anthropogenic. The growing trend in global industrialization ensures that more metals could be dispersed even in pristine ecosystems. To fuel industrialization, more metal ore mines have to be discovered and explored. These explorations often result in landscape disturbance, soil degradation and environmental contamination by unwanted mining constituents. Mine tailings brought up to the ground surface often serve as the main source of contaminants when these pyrite-rich materials oxidize. The oxidation of mine tailings results in proton generation, coupled with the dissolution of metals and other cations Unwanted anionic constituents are also produced. The so-called ＂acid mine drainage＂ may affect the productivity of farmlands and stability of receiving streams and other bodies of water-acidifying the waters and enriching the ecosystem with metals, i.e., high total dissolved solids. The acidified overburden materials become inhospitable to plant and microbial life as they are typically low in organic matter content and infertile. This exposes the landscape to runoff and erosion.  相似文献   

Attenuation of aqueous metal transport at two natural acid rock drainage occurrences in the Yukon Territory, Canada     

Y.T. John Kwong 《中国地球化学学报》2006,25(B08):229-230

Naturally acidic drainage associated with pyritic black shale has been observed in many locations in the Yukon Territory. While not necessarily linked to known mineral deposits, most of these natural acid rock drainage occurrences show elevated dissolved concentrations of trace elements, especially zinc, nickel, copper, cadmium and arsenic. Based on field observations, microbial investigation, chemical analyses and geochemical modeling, the fate and transport of potentially deleterious elements at two natural acid drainage occurrences with slightly different settings are examined. The Macintosh Creek is a small, acidic stream （pH 2.98-3.40）, 2 km long, located in the Macmillan Pass area of east-central Yukon amidst known sedimentary exhalative massive sulfide mineralization but remains undisturbed by exploration activities. Its trace metal content is apparently derived from groundwater discharges, which gave as much as 5.0, 2.5, 0.7, 0.13 and 0.03 mg/L ofZn, Ni, Cu and As, respectively. Interaction and sorption reactions with algal mats, biofilms and iron oxyhydroxides appear to be the dominant mechanisms attenuating aqueous contaminant transport along the stream. Cryogenic precipitation further consolidates the ferricrete formation and reduces the mobility of the sorbed metals. The tributaries of the Engineering Creek along the Dempster Highway in northern Yukon drain through a series of dolomite, phyllite, argillite, limestone, black shale, sandstone and conglomerate with no known concentration of mineralization. In this area, the water chemistry fully reflects the local geology with acidic streams invariably associated with black shale occurrences. Groundwater seeps in the headwaters area of the km-180 Creek completely enclosed in black shale gave pH 3.0 and as much as 148, 39, 2.9 and 9.1 mg/L of Zn, Ni, Cu and As, respectively. Sorption with iron oxyhydroxide and organic matter appear to dominate the attenuation of contaminant transport along the stream. However, once entered into carbonate-dominated terrains, secondary carbonate minerals exercise additional geochemical control on the local water chemistry as a result of neutralization.  相似文献   

日本东北宫城北部1962年M6．5地震孕震区的电磁不均匀性     

Y．Mitsuhata  Y．Ogawa  M．Mishina  T．Kono  T．Yokokura  T．Uchida  朱大庆 《世界地震译丛》2003,(2):63-68

为了研究日本东北部官城县境内1962年官城北部M6．5地震的孕震区大地电阻率结构，我们进行了大地电磁测量。二维反演表明，在该地区的地壳上部存在一个深的导电层，其上覆盖有高电阻带。该高电阻带之上还被认出有一个正航磁异常存在，人们把它解释为一个北上山地地下深成花岗岩岩体。通过与地震活动性进行比较我们发现，微震只发生在深导电层上方和高阻带里，并且几个S波反射体正好位于深导电区上方。由于S波反射体表明其下有流体存在，深导电层可以被解释为是一个充满流体的区带。而且我们认为，流体从导电性的充满流体的区带向高阻的深成花岗岩岩体的渗流可成为一种触发地震。  相似文献   

自相似和自仿射分形裂纹力学     

A．Yavari S．Sarkani E．T．MoyerJr张乃铃  安镇文陈学忠 《世界地震译丛》2003,(3):63-80

研究了断裂面分形特征的力学特征，同时研究了自相似和自仿射分形裂纹尖端附近应力和应变的奇异性结构，讨论了二维和三维固体中分形裂纹的3种经典断裂型式和第四种断裂型式。发现分形断裂力学中有6种断裂型式。同时，结果表明J积分与路径有关。阐明了文献中提出修改的、且被证明与路径无关的，积分仅局部与路径无关，而且没有物理意义。可以推测，分形，积分应当是单位裂纹扩展分形测度的势能释放率。我们计算了某些应变硬化材料中分形裂纹应力知应变奇异性的幂。结果显示，分形裂纹尖端的应力和应变比光滑裂纹的应力和应变有较弱的奇异性。  相似文献   

泥炭在污水处理中的用途   总被引：3，自引：0，他引：3  

马尔.  T  穆学五 《国土资源信息化》1997,(6):13-16

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放旋喷固结全的物理力学性状研究     

周勇  徐进 《地质灾害与环境保护》1997,8(3):28-32,53

通过单轴抗压试验，剪切试验，变形试验及渗透性试验等方法，对旋喷固结体的物理力学性状和渗透性进行了研究。结果表明，旋喷固结体具有良好的物理力学性质和较低的渗透性，呆完全发迹天然土的性质。  相似文献   

借助简化的毕奥—罗森博姆模型根据斯通利波测井资料快速反演岩层的渗…     

Xiaom.  T 朱希安 《国外煤田地质》1997,(3):48-53

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