Point-block covariance: A general solution for the two-dimensional stationary random functions

The application of the theory of random functions to problems of ore evaluation may involve computations of the covariance between the mean value of a given block and the functional value at a given point. However, an analytical solution for such a covariance does not exist for nonspherical blocks and for commonly applied models of covariance functions. Further, because this covariance is a function of the spatial arrangements of the block and the point, it has to be evaluated numerically each time for given point—block arrangements. This paper presents a readily available general solution to this problem in the form of a series of graduated curves which, together with some geometric manipulations, may be used to compute the covariance between a pointand a two-dimensional block for all possible point—block arrangements. The availability of the graph thus eliminates the necessity of using the time-absorbing programs on computers for such computations. Finally, many of the approximations that are made in order to avoid cumbersome covariance evaluations are no longer necessary due to the ease of such computations with the help of the graph provided.     

Evolution and observational signature of diffused antiworld

The existence of macroscopic regions with antibaryon excess in the baryon asymmetric Universe with general baryon excess is the possible consequence of practically all models of baryosynthesis. Diffusion of matter and antimatter to the border of antimatter domains defines the minimal scale of the antimatter domains surviving to the present time. A model of diffused antiworld is considered, in which the density within the surviving antimatter domains is too low to form gravitationally bound objects. The possibility to test this model by measurements of cosmic gamma ray fluxes is discussed. The expected gamma ray flux is found to be acceptable for modern cosmic gamma ray detectors and for those planned for the near future.     

现代浮游有孔虫对南海西南部上升流的响应

现代夏季风系统导致了南海西南部（越南岸外）上升流的发育,但浮游有孔虫对夏季上升流的响应如何尚缺乏实测资料,这不利于准确地利用有孔虫来重建古上升流的活动进而反演过去夏季风的强度变化。本研究利用2014年4月14日至11月1日布放于南海西南部夏季上升流区的时间序列沉积物捕获器材料,详细鉴定并定量统计了其所含浮游有孔虫类型。通过分析样品中浮游有孔虫各属种的通量和百分含量变化,结合区域气候环境资料,探讨南海西南部夏季上升流区浮游有孔虫对夏季风的响应,为古上升流与夏季风研究提供现代依据。研究结果表明初级生产力是控制上升流区浮游有孔虫通量变化的首要因素,喜营养种在上升流发育期增多而寡营养种含量下降。因此高表层生产力指示种,如Neogloboquadrina dutertrei可能是追溯南海西南部夏季上升流变化最可靠的指标。

     

Decay of a highly eccentric satellite

The re-entry phase of a highly eccentric satellite is discussed. Numerical simulations allowing the prediction of the exact date of re-entry of a highly eccentric satellite are exposed.It is shown that under very particular circumstances the life of the satellite can be extended by a few days. The number of final revolutions of the rapidly contracting orbit depends critically on the air density between 70 km and 100 km.Re-entry of the European scientific satellite HEOS-1 predicted for 28 October, 1975 is near such a situation.     

Über den Eisengehalt von Alumosilikaten aus Quarzknauern

Zusammenfassung Der Eisengehalt von Andalusiten und Disthenen aus Quarzknauern im Gebiet des Ötztaler—Stubaier Altkristallins wurde regional untersucht. Der Gehalt and Gesamteisen in primären Disthen liegt zwischen 0,17 und 0,22 Gew.% Fe₂O₃, während primäre Andalusite zwischen 0,26 und 1,93 Gew.% Fe₂O₃ schwanken. Dieser Unterschied in den Andalusiten wird auf ein wechselndes Angebot von Fe₂O₃ aus dem Nachbargestein der Knauern zurückgeführt.Ein Zusammenhang zwischen dem Eisengehalt der Andalusite und den verschiedenen Umwandlungsstadien Andalusit—Disthen konnte nicht nachgewiesen werden.

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On the iron content of alumosilicates in quartz nodules

Summary A determination of the regional distribution of the ironcontent of andalusites and kyanites in quartz-segregations of the Oetztal—Stubai crystalline complex gave values of 0.17–0.22% for the total iron in primary kyanite and 0.26–1.93% in andalusite. This difference is probably due to a variation in the Fe₂O₃-content in the country rocks of the quartz veins. No relationship between the iron-content in andalusite and the different stages of transformation from andalusite to kyanite could be established.

     

Ecological-geochemical assessment of the state of the Volga source of water supply to Moscow

Long-term observational data (1992?C2009) on heavy metal (Cu, Zn, Pb, Cr, Ni, V, Mo, Co, Fe, and Mn) content of different links in the Ivankovo Reservoir ecosystem are used to consider the regularities in the distribution and behavior of heavy metals in the system anthropogenic pollution sources-reservoir and its drainage area, thus enabling the assessment of the pollution level of the Volga Source of water supply to Moscow.     

Evidence for short term changes in the intensity and spectrum of hard X-rays from Cyg X-1

The paper presents experimental evidence for the existence of fast intensity fluctuations with time scales of the order of a minute in the X-ray emission from Cyg X-1 at energies greater than 29 keV. Spectral variations over time intervals of 20–25 min are also observed in the same energy range. Whereas, similar intensity and spectral fluctuations have been reported earlier at lower energies the observations presented here is the first evidence for the existence of similar fluctuations at high energies.     

PEDOGENESIS IN LATE PREHISTORIC INDIAN MOUNDS,UPPER MISSISSIPPI VALLEY

Inceptisols are developed on silt loam, loam, and sandy loam Indian mounds at the Keller Mound Group and Bluff Top Mound in northeastern Iowa. The mounds date to the Allamakee Phase of the Late Woodland Period (ca. 1650–1250 B.P.) and are built with fill obtained from the A, E, and upper B horizons of pre-existing soils (Alfisols). Differences in the morphologic and chemical characteristics of soils on different mounds are attributed to textural differences of the mounds' fill. Coarse-textured mound fill is pedogenically altered at a faster rate than fine-textured fill, but total carbon percentage of the A horizon attains a steady state faster in fine-textured mound fill. Total phosphorus content is used to determine from which horizons of pre-existing soils the specific layers of mound fill originated. Rates and pathways of pedogenesis in mound fill may not provide good analogues for the early stages of soil development in materials that have not undergone previous weathering and subsequent modification by humans. Nevertheless, mound soils are useful benchmarks for some pedologic studies since they provide time lines for evaluating minimum rates for development of argillic and albic horizons, as well as attainment of the Alfisol order.     

Principles of tabling

The mechanism of concentration on the shaking table is discussed and a fresh attempt is made to obtain the theoretical model describing the velocity of a fluid in depth and time when in contact with a symmetrically reciprocating surface.The significance of the many design and operational variables and their interrelationships are examined. The various areas where the shaking table plays its role are then considered.The relevant features of micropanner, superpanner and the subsequent macropanner and pulsepanner are also treated since they all, like the shaking table, have the differential motion in common.     

The first extra-large helium-rich gas field identified in a tight sandstone of the Dongsheng Gas Field,Ordos Basin,China

Science China Earth Sciences - Helium gas is a scarce but important strategic resource, which is usually associated with natural gas. Presently, only one extra-large helium-rich gas field has been...