粤连电厂拦灰坝土石混合料碾压试验研究

对拦灰坝土石混合料进行3种不同铺填厚度、3种不同加水量、5种振动碾压遍数组合的现场试验,通过测试碾压前后的颗粒组成,沉降量、变形模量、干湿密度等确定1组优化参数作为现场施工控制参数,并对试验结果进行了分析,提出了相应的处理措施和建议。     

Synthesis and Characterization of an Extractant [Bmim]PF_6 for Lithium Ion

正With the rapid increasing demand of metal lithium and its compounds in science and technology,studies on lithium recovery though lithium ion extraction from salt lake brines are blooming bacause more than 60 percent of     

Structure of Cu-bearing orthopyroxene, Mg(Cu.56,Mg.44)Si2O6, and behavior of Cu2+ in the orthopyroxene structure

Cu-bearing pyroxene, Mg(Cu.₅₆,Mg.₄₄)Si₂O₆, has been synthesized by a flux method and crystal structure refinement has been performed by single crystal X-ray diffraction. It is found that the crystal structure is orthorhombic (space group Pbca) with unit cell dimensions of a=18.221(4), b=8.890(1), c=5.2260(7)Å and the cell volume of 846.5( )3ų. In the M2-site one of the M-O bonds(M-O3B) is extremely expanded from 2.444(2) in enstatite to 2.732(2), thus the coordination polyhedron around M2-site is regarded as square pyramidal rather than square planar or octahedral. It is also found that the M1-site in the pyroxene structure is occupied almost exclusively by Mg, while the M2-site is almost evenly occupied by Mg and Cu. The observed extreme site preference shown by Cu²⁺ is unusual among the divalent cations with similar ionic sizes.     

Global Correlations of Ocean Ridge Basalt Chemistry with Axial Depth: a New Perspective

The petrological parameters Na₈ and Fe₈, which are Na₂O andFeO contents in mid-ocean ridge basalt (MORB) melts correctedfor fractionation effects to MgO = 8 wt%, have been widely usedas indicators of the extent and pressure of mantle melting beneathocean ridges. We find that these parameters are unreliable.Fe₈ is used to compute the mantle solidus depth (P_o) and temperature(T_o), and it is the values and range of Fe₈ that have led tothe notion that mantle potential temperature variation of T_P= 250 K is required to explain the global ocean ridge systematics.This interpreted T_P = 250 K range applies to ocean ridges awayfrom ‘hotspots’. We find no convincing evidencethat calculated values for P_o, T_o, and T_P using Fe₈ have anysignificance. We correct for fractionation effect to Mg^# = 0·72,which reveals mostly signals of mantle processes because meltswith Mg^# = 0·72 are in equilibrium with mantle olivineof Fo_89·6 (vs evolved olivine of Fo_{88·1–79·6}in equilibrium with melts of Fe₈). To reveal first-order MORBchemical systematics as a function of ridge axial depth, weaverage out possible effects of spreading rate variation, local-scalemantle source heterogeneity, melting region geometry variation,and dynamic topography on regional and segment scales by usingactual sample depths, regardless of geographical location, withineach of 22 ridge depth intervals of 250 m on a global scale.These depth-interval averages give Fe₇₂ = 7·5–8·5,which would give T_P = 41 K (vs 250 K based on Fe₈) beneathglobal ocean ridges. The lack of Fe₇₂–Si₇₂ and Si₇₂–ridgedepth correlations provides no evidence that MORB melts preservepressure signatures as a function of ridge axial depth. We thusfind no convincing evidence for T_P > 50 K beneath globalocean ridges. The averages have also revealed significantcorrelations of MORB chemistry (e.g. Ti₇₂, Al₇₂, Fe₇₂,Mg₇₂, Ca₇₂, Na₇₂ and Ca₇₂/Al₇₂) with ridge axial depth. Thechemistry–depth correlation points to an intrinsic linkbetween the two. That is, the 5 km global ridge axial reliefand MORB chemistry both result from a common cause: subsolidusmantle compositional variation (vs T_P), which determines themineralogy, lithology and density variations that (1) isostaticallycompensate the 5 km ocean ridge relief and (2) determine thefirst-order MORB compositional variation on a global scale.A progressively more enriched (or less depleted) fertileperidotite source (i.e. high Al₂O₃ and Na₂O, and low CaO/Al₂O₃)beneath deep ridges ensures a greater amount of modal garnet(high Al₂O₃) and higher jadeite/diopside ratios in clinopyroxene(high Na₂O and Al₂O₃, and lower CaO), making a denser mantle,and thus deeper ridges. The dense fertile mantle beneath deepridges retards the rate and restricts the amplitude of the upwelling,reduces the rate and extent of decompression melting, givesway to conductive cooling to a deep level, forces melting tostop at such a deep level, leads to a short melting column,and thus produces less melt and probably a thin magmatic crustrelative to the less dense (more refractory) fertile mantlebeneath shallow ridges. Compositions of primitive MORB meltsresult from the combination of two different, but geneticallyrelated processes: (1) mantle source inheritance and (2) meltingprocess enhancement. The subsolidus mantle compositional variationneeded to explain MORB chemistry and ridge axial depth variationrequires a deep isostatic compensation depth, probably in thetransition zone. Therefore, although ocean ridges are of shalloworigin, their working is largely controlled by deep processesas well as the effect of plate spreading rate variation at shallowlevels. KEY WORDS: mid-ocean ridges; mantle melting; magma differentiation; petrogenesis; MORB chemistry variation; ridge depth variation; global correlations; mantle compositional variation; mantle source density variation; mantle potential temperature variation; isostatic compensation     

Bedload transport and bed resistance associated with density and turbidity currents

Turbidity currents in the ocean are driven by suspended sediment. Yet results from surveys of the modern sea floor and turbidite outcrops indicate that they are capable of transporting as bedload and depositing particles as coarse as cobble sizes. While bedload cannot drive turbidity currents, it can strongly influence the nature of the deposits they emplace. This paper reports on the first set of experiments which focus on bedload transport of granular material by density underflows. These underflows include saline density flows, hybrid saline/turbidity currents and a pure turbidity current. The use of dissolved salt is a surrogate for suspended mud which is so fine that it does not settle out readily. Thus, all the currents can be considered to be model turbidity currents. The data cover four bed conditions: plane bed, dunes, upstream‐migrating antidunes and downstream‐migrating antidunes. The bedload transport relation obtained from the data is very similar to those obtained for open‐channel flows and, in fact, is fitted well by an existing relation determined for open‐channel flows. In the case of dunes and downstream‐migrating antidunes, for which flow separation on the lee sides was observed, form drag falls in a range that is similar to that due to dunes in sand‐bed rivers. This form drag can be removed from the total bed shear stress using an existing relation developed for rivers. Once this form drag is subtracted, the bedload data for these cases collapse to follow the same relation as for plane beds and upstream‐migrating antidunes, for which no flow separation was observed. A relation for flow resistance developed for open‐channel flows agrees well with the data when adapted to density underflows. Comparison of the data with a regime diagram for field‐scale sand‐bed rivers at bankfull flow and field‐scale measurements of turbidity currents at Monterey Submarine Canyon, together with Shields number and densimetric Froude number similarity analyses, provide strong evidence that the experimental relations apply at field scale as well.     

制造金刚石钻头的快速电镀法研究

总结了两年多来采用较高电流密度法制造金刚石钻头的经验,运用快速电镀法制造金刚石钻头不仅大大提高了生产效率,而且提高了金刚石钻头的质量。     

主应力轴循环旋转下高密实粉土稳定性影响研究

为研究主应力轴循环旋转对粉土性状影响,对长江入海口高密实饱和粉土进行了主应力轴180°转幅的循环旋转试验。试验发现,等向固结的高密实粉土在恒定动剪应力比的主应力轴循环旋转下能发生孔压达到初始围压水平的液化破坏,但液化前孔压开展会因动应力水平的不同而呈现以渐变相态点和激变相态点区分的3阶段变化形式,或仅以激变相态点区分的两阶段变化形式。试样应变开展则始终呈现由崩塌点区分的两阶段变化形式,且孔压激变相态点与应变崩塌点同步反映了土体结构崩塌状态,崩塌状态时主应变差双向幅值限制在0.2%～0.4%这一较小范围内。试样进行主应力轴旋转达到崩塌时的应力状态与频率无显著关系,可由 - 空间中一条准不稳定状态线归一化。而以崩塌状态为终点进行归一化的主应力轴循环旋转下孔压振次曲线,可用修正的Seed公式进行较好拟合     

An infrared spectroscopic and single-crystal X-ray study of malayaite, CaSnSiO5

Powder infrared spectroscopy and X-ray diffraction techniques on single crystals were used to study the thermal behaviour of malayaite, CaSnSiO₅. Infrared spectra show a discontinuity in the temperature evolution of phonon frequencies and absorbance near 500 K. However, crystal structure data collected at 300, 450, 550, 670, and 750 K show no evidence of a symmetry-breaking phase transition and no split positions. The most obvious change with heating is a tumbling motion of the SnO₆ octahedra and an increase of the anisotropic displacement factors of Ca. The thermal evolution of the mean-square vibrational amplitude of the Ca atom shows a pronounced change in slope near 500 K. The evidence suggests that the 500 K anomaly in malayaite is more similar in character to the 825 K (β-γ) transition as opposed to the 496 K (α-β) transition in synthetic titanite. Received: 26 March 1998 / Revised, accepted: 23 December 1998     

A Middle Miocene carbonate embankment on an active volcanic slope: Ilhéu de Baixo,Madeira Archipelago,Eastern Atlantic

Carbonate factories on insular oceanic islands in active volcanic settings are poorly explored. This case study illuminates marginal limestone deposits on a steep volcanic flank and their recurring interruption by deposits linked to volcaniclastic processes. Historically known as Ilhéu da Cal (Lime Island), Ilhéu de Baixo was separated from Porto Santo, in the Madeira Archipelago, during the course of the Quaternary. Here, extensive mines were tunnelled in the Miocene carbonate strata for the production of slaked lime. Approximately 10 000 m³ of calcarenite (−1 to 1ø) was removed by hand labour from the Blandy Brothers mine at the south end of the islet. Investigations of two stratigraphic sections at opposite ends of the mine reveal that the quarried material represents an incipient carbonate ramp developed from east to west and embanked against the flank of a volcanic island. A petrographic analysis of limestones from the mine shows that coralline red algae from crushed rhodoliths account for 51% of all identifiable bioclasts. This material was transported shoreward and deposited on the ramp between normal wave base and storm wave base at moderate depths. The mine's roof rocks are formed by Surtseyan deposits from a subsequent volcanic eruption. Volcaniclastic density flows also are a prevalent factor interrupting renewed carbonate deposition. These flows arrived downslope from the north and gradually steepened the debris apron westwards. Slope instability is further shown by a coral rudstone density flow that followed from growth of a coral reef dominated by Pocillopora madreporacea (Lamarck), partial reef collapse, and transport from a more easterly direction into a fore‐reef setting. The uppermost facies represents a soft bottom at moderate depths in a quiet, but shore‐proximal setting. Application of this study to a broader understanding of the relationship between carbonate and volcaniclastic deposition on oceanic islands emphasizes the susceptibility of carbonates to dilution and complete removal by density flows of various kinds, in contrast to the potential for preservation beneath less‐disruptive Surtseyan deposits. Copyright © 2013 John Wiley & Sons, Ltd.     

高密度电阻率法的2.5维反演软件

介绍了不平地形条件下高密度电阻率法2.5维反演的算法和程序,该程序可用于九种常用电极装置观测结果的反演。对理论和实测数据的反演结果表明,该算法正确,程序运行稳定,反演效果很好。