硫酸盐渍土含水率单次递减条件下的盐胀特性

为探究硫酸盐渍土在含水率递减下的盐胀特性,通过自主设计的试验装置,在室内开展了11组含水率单次递减下的盐胀试验,共历时2 868 h。结果表明：在含水率单次递减下硫酸盐渍土的起胀含盐量约为1.2%。含盐量<1.2%时,土体干缩,干缩量与含盐量近似呈下凸的二次抛物线规律,且干缩峰值含盐量约为0.5%;含盐量≥1.2%时,土体膨胀,且盐胀率与含盐量近似呈线性增大规律。盐胀敏感含水率区间受含盐量影响很小,含盐量从1.5%增至4.0%,盐胀敏感含水率区间基本稳定。此外,含水率递减速率与含盐量呈负相关规律,同一含盐量的硫酸盐渍土,其含水率的递减速率随含水率的降低亦减慢。基于以上试验结果,进一步开展了4组单次降温下的盐胀对比试验,结果表明：含盐量升高时,起胀温度区间逐渐升高,盐胀敏感温度区间的区间范围逐渐扩大。单次降温下的盐胀率均高于含水率单次递减下的盐胀率,且随着含盐量的升高两试验条件下的盐胀率差值趋于一常数。研究结果对西北地区高含盐量的残余型硫酸盐渍土地基的盐胀性评价具有重要指导意义。     

Corotating and Propagating Disturbances in the Solar Wind Based on Monitoring of Interplanetary Scintillations at the LPA Radio Telescope of the Lebedev Physical Institute in 2017

Monitoring of interplanetary scintillations in 2017 is used as a basis for analyzing the dynamics of scintillation levels in periods preceding the arrival at the Earth of eight large-scale disturbances in the solar wind giving rise to strong geomagnetic storms. In six of the eight events, the dynamics of the scintillation level were mainly determined by the motion of corotating disturbances. In two events, coronal-mass ejections excited in the corona near the western limb of the Sun were observed against the background of corotating disturbances. In one of these cases, a magnetic storm was associated with a corotating flux, and in the other with a powerful propagating disturbance. Comparison with similar data obtained in 2016, also during the descending phase in solar activity, testifies to the existence of corotating disturbances with lifetimes of at least 20 solar rotations. These new results support the earlier conclusion that a weakening of scintillations is observed in the evening sector three to four days before the arrival of the compressed part of a disturbance to the Earth, which could be due to an appreciable lowering of the level of small-scale turbulence in the plasma in an extended region ahead of the frontal part of the disturbance. The interplanetary-scintillation monitoring data for 2017 show that, simultaneously with the associated magnetic storm, there is an enhancement of second-time-scale scintillations, which are most clearly manifest when the storm occurs during the evening or night-time hours. For the events considered, the increase in scintillations accompanying the magnetic storm is associated with an enhancement in the level of small-scale fluctuations in regions of the solar wind adjacent to the Earth when the storm is excited by a corotating disturbance, and with the perturbed ionosphere when the storm is excited by a flare-related disturbance.     

新疆库鲁克塔格地区新元古代层序地层学研究及对比

新疆库鲁克塔格地区上元古界可分为五个沉积层序,由下到上分别对应于贝义西组、照壁山组、阿勒通沟组、特瑞爱肯组至水泉组和汉格尔乔克组。第1层序由贝义西组构成,发育由粗碎屑斜坡扇和低水位楔构成的低水位体系域,向上逐渐变为粉砂岩、泥岩的海进体系域,并以向上变粗的退积准层序的高水位体系域结束,反映陆缘发展初期海平面的升降变化。第2层序由照壁山组构成,底部为粗粒石英砂岩,向上变为细粒砂岩、页岩互层,上部出现厚约30m的泥岩,顶部为紫红色砂岩,代表了由低水位经快速海进到高水位的变化过程,整体为水体较浅的滨浅海沉积环境。第3层序由阿勒通沟组构成,为冰成杂砾岩、砂岩、页岩组合,顶部出现厚2～3m的白云岩,沉积主体为低水位体系域,顶部白云岩为海进体系域,缺失高水位体系域。第4层序发育最为完整,特瑞爱肯组冰成杂砾岩为低水位体系域,冰成杂砾岩之上“盖帽碳酸盐岩”为海进体系域,扎摩克提组浊积岩、育肯沟组页岩、水泉组碳酸盐岩为高水位体系域,其中育肯沟组页岩为凝缩段沉积。第5层序低水位体系域由汉格尔乔克组冰成杂砾岩构成,顶部泥灰岩和白云岩为海进体系域,由于顶部被寒武系不整合覆盖,缺失高水位体系域。研究区上元古界层序基本可以和我国华南及印度Lesser Himalaya地区对比。     

Dynamics of Slope Processes in the Geysernaya River Valley (Kamchatka) According to the Interpretation Data of Multi-Temporal Space Images

Doklady Earth Sciences - The interpretation of high-resolution satellite images (0.5–3 m) of three time slices (1964, 2009, and 2017) allowed us to identify the areas of activation of modern...     

Mercury in Hydrobionts and Their Habitat in Grønfjorden,West Spitsbergen,in Early Springtime

The first data were obtained on the total mercury content in hydrobionts and their habitat in Grønfjorden, Spitsbergen, at the waste discharge sites of the settlement of Barentsburg in early spring 2017. The Hg concentration was below the detection limit in the water and varied from 7.1 to 42.3 ng/g of dry weight in the bottom sediments. Mercury concentration in the hydrobionts increased toward the inner fjord and was higher near the mouth of the Grøndalen River, which flows into the fjord. Elevated Hg concentrations at the mouth of the Grøndalen River indicate that much of the toxic metal is brought to the inner part of the fjord with riverine runoff, and this Hg source is likely more important than the surface supply of Hg transferred from local surface pollution centers at Barentsburg. The Hg concentration depended on the position of the marine organisms in the trophic chain and was the highest in the detritophage mollusks Thyasira gouldi, Cardium sp., and Macoma calcarea, the specialized predatory sea snail Cryptonatica affinis, and the cod Gadus morhua, which is a benthosophage–secondary predator. The total Hg concentrations in the hydrobionts and their habitat in Grønfjorden were generally relatively low and close to the background one.     

Palynostratigraphy of the Upper Cretaceous and Paleogene Deposits in the South of Western Siberia by Example of Russkaya Polyana Boreholes,Omsk Trough

The detailed study of Boreholes 8, 10, and 2 in the Russkaya Polyana district (Omsk Trough) made it possible to reveal the complex structure of the Upper Cretaceous sediments formed in unstable conditions of the marginal part of the Western Siberian basin. The Pokur, Kuznetsovo, Ipatovo, Slavgorod, and Gan’kino formations were subjected to palynological analysis and substantiation of their Late Cretaceous age. Eight biostratigraphic units with dinocysts and five units with spores and pollen from the Albian to the Maastrichtian were identified. The joint application of biostratigraphic and magnetostratigraphic methods made it possible to reveal the stratigraphic breaks in the studied sedimentary stratum and to estimate their scope. The age of the Lower Lyulinvor Subformation was specified in the marginal part of the Omsk Trough. The ingression traces of the Western Siberian basin in the Albian were found for the first time in the considered region.     

Reconstruction of the upper pleistocene glaciation of East PamirRekonstruktion der oberpleistozänen vergletscherung des ostpamirsReconstruction de la glaciation du Pamir oriental dans le pleistocène supérieur

The paper deals with type, age, and climatic conditions of the last vast glaciation in the East Pamir Mountains. The combination of paleobotanic and geomorphological data as well as absolute age dating of the Kara-Kul lake terrace (27,700 ± 700 years old) supports the thesis that maximum glaciation occurred in the Upper Pleistocene, 14–15 thousand years ago. By special calculations it was established that the tectonic factor of glaciation practically did not exist. This confirmed the existing opinion of a number of scientists that by the beginning of the Upper Pleistocene the Pamir Mountains had almost achieved their present altitude. The analysis of paleobotanic literature permitted the assumption that the amount of precipitation was about the same as it is now: 750 mm/year at an altitude of 4950 m (altitude of the present-day firn line). It was established that the Upper Pleistocene glaciation was caused only by general climatic cooling.     

超大型沉井首次接高受力及变形规律初探

依托马鞍山长江大桥南锚碇沉井的首次接高,对其竖向沉降、隔墙墙底土压力和隔墙底板受力情况进行了监测。结果表明,超大型沉井兼有条形基础的特点和整体工作性能,能够承受较大的竖向变形,与单纯考虑地基承载力相比,更适合于按变形控制接高。沉井接高时普通隔墙下的土压力小于分区隔墙,并且普通隔墙下部土体会先达极限承载力,后续接高产生的荷载转而由分区隔墙（或井壁）来承担。沉井首节混凝土浇筑就已决定了隔墙底板的应力大小和分布情况,后续接高不会再引起大的改变;隔墙底板中间部分受力较小,外围拉应力较大,通过井壁外土体的密实回填可有效降低此部分拉应力。     

恒山地区部分熔融地质体填图方法的尝试

五台群地层呈东西向分布在恒山东段中部,其北为高角闪岩相的恒山片麻杂岩,两者岩性呈渐变过渡关系,由此萌发出片麻杂岩是五台群地层部分熔融而来的思路。经过填图实践,总结出地层与片麻岩体之间存在着仍属地层范畴的片麻岩层这一无序岩石地层单位,并建立起它的填图标志。与地层呈渐变关系的片麻岩体外貌复杂、边界不清,不同于具有一定侵入关系、边界明显、成分均一的片麻岩体,据此划分了原地片麻岩体与异地片麻岩体两个系列。     

Determination of paleo-pressure for a natural gas pool formation based on PVT characteristics of fluid inclusions in reservoir rocks——A case study of Upper-Paleozoic deep basin gas trap of the Ordos Basin

~~Determination of paleo-pressure for a natural gas pool formation based on PVT characteristics of fluid inclusions in reservoir rocks——A case study of Upper-Paleozoic deep basin gas trap of the Ordos Basin~~