Development of a real-time algorithm for detection of solar wind discontinuities

A study is presented of an algorithm, based on the statistical analysis of interplanetary magnetic field data, for the real-time detection of discontinuities in the solar wind. The analysis is based on the application of a sliding or searching algorithm together with a minimum variance treatment. A demonstration is given for a Pioneer data set from 29 August, 1966. This particular data set was chosen because it has been extensively studied (in terms of the fast forward MHD shock wave) by previous groups who utilized the three-dimensional Rankine-Hugoniot shock equations after identifying the shock on a subjective basis. Our procedure differs in that it is perfectly objective because of its searching technique. For this particular data set we identify the original shock with excellent agreement with the earlier studies of its normal vector, as well as an additional shock and tangential discontinuity, neither of which had been identified previously.     

The Hα-cyclonic spectra of a flare loop system on 1981 April 27

The data such as the H-spectrum-spectroheliographic (SSHG) observations, the H-chromospheric observations, etc., of a flare loop prominence which occurred on the western solar limb on 1981 April 27 have been obtained at Yunnan Observatory. The distribution of the internal motions and the macroscopical motion of the flare loop prominence with time and space in the course of its eruption and ascension is derived from the comprehensive analysis of the data. The possible physical pictures and the instability of the motions of the loop are inferred and discussed.     

A simple mathematical model for soil nail and soil interaction analysis

Soil nails have been widely used to stabilize slopes and earth retaining structures in many countries and regions, especially, in Hong Kong. The analysis of the interaction between a soil nail and the surrounding soil is of great interests to both design engineers and researchers. In this paper, authors present a simple mathematical model for the interaction analysis of a soil nail and the surrounding soil considering a few key factors which are soil dilation, bending of the soil nail, vertical pressure, and non-linear subgrade reaction stiffness. The lateral subgrade reaction between the soil and the soil nail is assumed to obey a hyperbolic relation. Reported test data in the literature are used to verify the present model. The contributions of the soil-nail bending on the pull-out resistance are evaluated in two case studies.     

Micro-XANES mapping of sulphur and its association with magnesium and phosphorus in the shell of the brachiopod, Terebratulina retusa

Biominerals are natural composite materials comprising organic and inorganic components. Detailed knowledge of the nature and distribution of both components is a crucial requirement in order to advance our understanding of biomineral formation, their material properties and preservation potential as well as the interpretation of environmental data. Detailed chemical data are essential for our understanding of the nature and distribution of such components. Micro-XANES mapping at the sulphur K-edge reveals that, in the brachiopod Terebratulina retusa, the sulphate concentration is higher in the outer (primary) layer than in the calcite fibres of the secondary layer. This is co-incident with a higher magnesium concentration. In contrast, the sheaths surrounding the calcite fibres contain sulphur as thiol, confirming the presence of protein while, the sulphur within the fibres themselves, occurs as sulphate. Micro-XANES analysis of the insoluble organic extract from T. retusa indicates the presence of organic sulphate while Micro-Raman spectroscopy confirms that structurally substituted sulphate (SSS) is also present although semi-quantitative Raman spectroscopy carried out in this spectral region (wavenumbers 900–1200) indicates that the sulphate present is at the threshold of detection by Raman spectroscopy. The distribution of phosphorus in the shell of T. retusa correlates well with that of protein indicating the presence of phosphorylated proteins in the periostracum, the sheaths surrounding the calcite fibres and the interface between the primary and secondary layer.     

Case history of controlling a landslide at Panluo open-pit mine in China

Controlling of landsides safely and economically is a great challenge to mine operators because landslides are major geological problems especially in open-pit mines. In this paper, a case history at Panluo open-pit mine is presented in detail to share the experiences and lessons with mine operators. Panluo open-pit mine is located in the southwestern Fujian province of China. It is the largest open-pit iron mine in the Fujian province and was planned in 1965 and is in full operation from 1978. In July 1990, an earthquake of magnitude 5.3 in Taiwan Strait and big rainstorms impacted the mine slope, causing tension cracks and rather large-scale failures, and forming a U-shaped landslide. Total potential volume was estimated to be up to 1.0 × 10⁶ m³. This directly threatened the mine production. In order to protect the mine production and the dwellers’ safety around, a dynamic comprehensive method was implemented including geotechnical investigations, in-situ testing and monitoring, stability analysis, and many mitigation and preventive measures. These measures slowed down the development and further occurrence of the landslide. The results showed that the landslides were still active, it was slowed with the control measures and moved rapidly with rainfall and mining down. However, no catastrophic accidents occurred and the pit mining was continued till it was closed at the elevation of 887 m in 2000. As a successful case of landslide control at an open-pit mine for 10 years, this paper reports the controlling measures in details. These experiences of landslide control may be beneficial to other similar mines for landslide control.     

Wind wave-forced fine sediment erosion during the slack water periods in Hangzhou Bay,China

The shallow water wave simulation model-SWAN incorporated with a simple fine sediment erosion model is applied to Hangzhou Bay, China, to model the horizontal distribution of the maximum bottom orbital velocity and corresponding fine sediment erosion rates induced by: (1) southeasterly steady winds (5, 20 and 30 m/s), (2) southwesterly steady winds (5 and 20 m/s); (3) northwesterly steady winds (5 and 20 m/s); (4) east-southeasterly steady winds (5 and 20 m/s); (5) easterly steady winds (5 and 20 m/s) under closed and unclosed boundaries; and (6) unsteady winds during the slack water periods. Results suggest: (1) the steady wind wave-induced maximum bottom orbital velocities and corresponding fine sediment erosion rates generally increased with the increasing steady winds; (2) closed and unclosed boundary conditions had more significant influences on modeled fine sediment erosion rates under 5 m/s easterly steady winds than 20 m/s; and (3) steady and unsteady wind wave-induced maximum bottom currents could be significant in eroding fine sediment bed in Hangzhou Bay. The results show implications for geomorphology, sedimentology, coastal erosion, and environmental pollution mitigation in Hangzhou Bay.     

Environmental contamination of Zn,Cd, Ni,Cu, and Pb from industrial areas in Hamadan Province,western Iran

Eleven surface soil samples from calcareous soils of industrial areas in Hamadan Province, western Iran were analyzed for total concentrations of Zn, Cd, Ni, Cu and Pb and were sequentially extracted into six fractions to determine the bioavailability of various heavy metal forms. Total Zn, Cd, Ni, Cu and Pb concentrations of the contaminated soils were 658 (57–5,803), 125.8 (1.18–1,361), 45.6 (30.7–64.4), 29.7 (11.7–83.5) and 2,419 (66–24,850) mg kg⁻¹, respectively. The soils were polluted with Zn, Pb, and Cu to some extent and heavily polluted with Cd. Nickel values were not above regulatory limits. Copper existed in soil mainly in residual (RES) and organic (OM) fractions (about 42 and 33%, respectively), whereas Zn occurred essentially as RES fraction (about 69%). The considerable presence of Cd (30.8%) and Pb (39%) in the CARB fraction suggests these elements have high potential biavailability and leachability in soils from contaminated soils. The mobile and bioavailable (EXCH and CARB) fractions of Zn, Cd, Ni, Cu, and Pb in contaminated soils averaged (7.3, 40.4, 16, 12.9 and 40.8%), respectively, which suggests that the mobility and bioavailability of the five metals probably decline in the following order: Cd = Pb > Ni > Cu > Zn.     

Composition, P-T parameters, and metasomatic transformations of mafic schists of the Svyatoi Nos Peninsula, Eastern Baikal Area

The paper reports data on rock and mineral compositions from the Svyatonosskaya Formation, which is a continuation of the Ol’khon Series in the northern part of the Svyatoi Nos Peninsula, eastern shore of Lake Baikal. The pyroxene-amphibole-plagioclase schists (metagabbro) are replaced there by the garnet-biotite-quartz assemblage, which was formed, according to the data of various geothermometers and calculations by the THERMOCALC computer program, under conditions corresponding to the transition from the granulite (848–811°C) to high grades of the amphibolite (715–670°C) facies under high pressures (8.7 ±1.6 kbar). In petrogenetic grids, these conditions fall onto the line of the onset of eclogitization. In nature these rocks are a continuation of the Chernorudskaya-Barakchinskaya zone of elevated pressures in the Ol’khon area. The metasomatic rocks were formed simultaneously with strike-slip faulting, when coupled zones of relatively high-(eclogite-like) and low-pressure (quartzite-marble melange) developed at the inflow of SiO₂ and K₂O and the removal of MgO and CaO. Analogous compositional changes in gneisses and schists in tectonic extension zones in Ol’khon Island and neighboring areas occurred during the development of migmatites. The migmatization of the gneisses was likely coupled with the garnetization of mafic schists in high-pressure zones and the formation of eclogite-like rocks replacing marbles. The accompanying graphitization of this block suggests that the metasomatic fluid had a hydrocarbon-hydrogen composition.     

Silicon isotope fractionation in bamboo and its significance to the biogeochemical cycle of silicon

A systematic investigation on silica contents and silicon isotope compositions of bamboos was undertaken. Seven bamboo plants and related soils were collected from seven locations in China. The roots, stem, branch and leaves for each plant were sampled and their silica contents and silicon isotope compositions were determined. The silica contents and silicon isotope compositions of bulk and water-soluble fraction of soils were also measured. The silica contents of studied bamboo organs vary from 0.30% to 9.95%. Within bamboo plant the silica contents show an increasing trend from stem, through branch, to leaves. In bamboo roots the silica is exclusively in the endodermis cells, but in stem, branch and leaves, the silica is accumulated mainly in epidermal cells. The silicon isotope compositions of bamboos exhibit significant variation, from −2.3‰ to 1.8‰, and large and systematic silicon isotope fractionation was observed within each bamboo. The δ³⁰Si values decrease from roots to stem, but then increase from stem, through branch, to leaves. The ranges of δ³⁰Si values within each bamboo vary from 1.0‰ to 3.3‰. Considering the total range of silicon isotope composition in terrestrial samples is only 7‰, the observed silicon isotope variation in single bamboo is significant and remarkable. This kind of silicon isotope variation might be caused by isotope fractionation in a Rayleigh process when SiO₂ precipitated in stem, branches and leaves gradually from plant fluid. In this process the Si isotope fractionation factor between dissolved Si and precipitated Si in bamboo (α_pre-sol) is estimated to be 0.9981. However, other factors should be considered to explain the decrease of δ³⁰Si value from roots to stem, including larger ratio of dissolved H₄SiO₄ to precipitated SiO₂ in roots than in stem. There is a positive correlation between the δ³⁰Si values of water-soluble fractions in soils and those of bulk bamboos, indicating that the dissolved silicon in pore water and phytoliths in soil is the direct sources of silicon taken up by bamboo roots. A biochemical silicon isotope fractionation exists in process of silicon uptake by bamboo roots. Its silicon isotope fractionation factor (α_bam-wa) is estimated to be 0.9988. Considering the distribution patterns of SiO₂ contents and δ³⁰Si values among different bamboo organs, evapotranspiration may be the driving force for an upward flow of a silicon-bearing fluid and silica precipitation. Passive silicon uptake and transportation may be important for bamboo, although the role of active uptake of silicic acid by roots may not be neglected. The samples with relatively high δ³⁰Si values all grew in soils showing high content of organic materials. In contrast, the samples with relatively low δ³⁰Si values all grew in soil showing low content of organic materials. The silicon isotope composition of bamboo may reflect the local soil type and growth conditions. Our study suggests that bamboos may play an important role in global silicon cycle.