基于数字全息显微的海洋浮游生物三维形貌快速重建方法研究

针对海洋浮游生物实时探测中,三维形貌特征难以快速获取的问题,本文提出了一种海洋浮游生物三维形貌快速重建的方法。基于离轴菲涅尔数字全息显微系统,通过改进相位恢复方法预消除相位畸变,直接得到正确的相位信息,进而对浮游生物三维形貌重建。该方法不需要进行后期复杂的相位补偿计算,就可以对浮游生物三维形貌进行快速重建,有利于对动态、微小尺寸的浮游生物进行实时探测及分析。论文对青岛近海岸浮游生物桡足类和夜光虫进行了三维形貌重建,分辨率可达到3.5μm。实验结果为离轴菲涅尔数字全息显微系统用于海洋浮游生物原位、实时探测的可行性提供了依据。     

New constraints on granulite facies metamorphism and melt production in the Lewisian Complex,northwest Scotland

In this study, we investigate the metamorphic history of the Assynt and Gruinard blocks of the Archean Lewisian Complex, northwest Scotland, which are considered by some to represent discrete crustal terranes. For samples of mafic and intermediate rocks, phase diagrams were constructed in the Na₂O–CaO–K₂O–FeO–MgO–Al₂O₃–SiO₂–H₂O–TiO₂–O₂ (NCKFMASHTO) system using whole‐rock compositions. Our results indicate that all samples equilibrated at similar peak metamorphic conditions of ~8–10 kbar and ~900–1,000°C, consistent with field evidence for in situ partial melting and the classic interpretation of the central region of the Lewisian Complex as representing a single crustal block. Melt‐reintegration modelling was employed in order to estimate probable protolith compositions. Phase equilibria calculated for these modelled undepleted precursors match well with those determined for a subsolidus amphibolite from Gairloch in the southern region of the Lewisian Complex. Both subsolidus lithologies exhibit similar phase relations and potential melt fertility, with both expected to produce orthopyroxene‐bearing hornblende granulites, with or without garnet, at the conditions inferred for the Badcallian metamorphic peak. For fully hydrated protoliths, prograde melting is predicted to first occur at ~620°C and ~9.5 kbar, with up to 45% partial melt predicted to form at peak conditions in a closed‐system environment. Partial melts calculated for both compositions between 610 and 1,050°C are mostly trondhjemitic. Although the melt‐reintegrated granulite is predicted to produce more potassic (granitic) melts at ~700–900°C, the modelled melts are consistent with the measured compositions of felsic sheets from the central region Lewisian Complex.     

煤系高岭石/醋酸钾插层复合物热相变研究

高岭石插层复合物作为新型矿物材料现已被广泛应用。然而,插层复合物热稳定性较难控制使其在聚合物中的应用一直受到限制。本文应用热分析、X射线衍射、质谱及发射红外光谱等表征技术对煤系高岭石/醋酸钾插层复合物受热分解产物及微结构变化进行了研究。结果表明,煤系高岭石/醋酸钾插层复合物热相变主要经历以下几个阶段:插层水脱嵌(约350℃),插层剂醋酸钾脱嵌(约400℃),脱羟基(约450℃),偏高岭石形成(450~550℃),KHCO3出现(约600℃),KHCO3热分解形成K2CO3和KAl Si O4出现(约700℃),热解产品K2Al2Si O4出现(约800℃),K4Al2Si2O3出现(900~1000℃),大量K3Al O3形成阶段(1100℃及以上)。此外,还发现通过控制插层率和加热温度,可实现高岭石插层复合物的可控分解、新物相合成与转变,从而有利于新材料的合成。     

地震信号的相位恢复及误差分析

常见的几种地震子波有:零相位子波、最小相位子波、最大相位子波和混合相位子波。以不同类型的信号为激发子波,对不同地层模型合成地震道。仅用原始合成地震道记录的振幅谱来恢复原始记录,讨论不同方法下,由于激发子波的不同,对比分析原始记录与恢复记录的差异,及其恢复效果。     

淮河流域(河南段)第四纪地层沉积规律

本文详细介绍了第四纪地层划分原则,确定了第四纪下限与各世内分的时间,对河南段各个时期地势、各统的沉积规律进行了阐述,确定了含水层主流相与边缘相.     

Phase Equilibria Constraints on the Chemical and Physical Evolution of the Campanian Ignimbrite

The Campanian Ignimbrite is a > 200 km³ trachyte–phonolitepyroclastic deposit that erupted at 39·3 ± 0·1ka within the Campi Flegrei west of Naples, Italy. Here we testthe hypothesis that Campanian Ignimbrite magma was derived byisobaric crystal fractionation of a parental basaltic trachyandesiticmelt that reacted and came into local equilibrium with smallamounts (5–10 wt%) of crustal rock (skarns and foid-syenites)during crystallization. Comparison of observed crystal and magmacompositions with results of phase equilibria assimilation–fractionationsimulations (MELTS) is generally very good. Oxygen fugacitywas approximately buffered along QFM + 1 (where QFM is the quartz–fayalite–magnetitebuffer) during isobaric fractionation at 0·15 GPa ( 6km depth). The parental melt, reconstructed from melt inclusionand host clinopyroxene compositions, is found to be basaltictrachyandesite liquid (51·1 wt% SiO₂, 9·3 wt%MgO, 3 wt% H₂O). A significant feature of phase equilibria simulationsis the existence of a pseudo-invariant temperature, 883 °C,at which the fraction of melt remaining in the system decreasesabruptly from 0·5 to < 0·1. Crystallizationat the pseudo-invariant point leads to abrupt changes in thecomposition, properties (density, dissolved water content),and physical state (viscosity, volume fraction fluid) of meltand magma. A dramatic decrease in melt viscosity (from 1700Pa s to 200 Pa s), coupled with a change in the volume fractionof water in magma (from 0·1 to 0·8) and a dramaticdecrease in melt and magma density acted as a destabilizingeruption trigger. Thermal models suggest a timescale of 200kyr from the beginning of fractionation until eruption, leadingto an apparent rate of evolved magma generation of about 10^–3km³/year. In situ crystallization and crystal settling in density-stratifiedregions, as well as in convectively mixed, less evolved subjacentmagma, operate rapidly enough to match this apparent volumetricrate of evolved magma production. KEY WORDS: assimilation; Campanian Ignimbrite; fractional crystallization; magma dynamics; phase equilibria     

多孔介质中非水相流体运移的数值模拟

针对多孔介质中水、气和非水相流体(NAPLs)的多相流动特点,建立了非水相流体(NAPLs)污染物迁移模型,分析了非水相流体在土壤非饱和区和地下水系统中的运移规律。通过有限元数值解对轻非水相流体和重非水相流体在土壤系统中的迁移过程进行模拟,得到了污染物的时空分布特征和污染范围。计算结果表明,数值模拟方法能够合理地描述非水相流体的运移过程和污染特征。土体渗透性和污染物残余饱和度是其重要影响因素。     

邢台7.2级地震的发震背景特征

主要从太阳黑子活动、地震迁移、地震韵律和月相等各方面,对邢台地震的发震背景进行了分析。结果显示,这些背景特征是很突出的。认为地震的发生,可能受到多种因素的影响和制约,研究发震背景特征对于我们认识地震和预测未来地震都是有一定意义的。     

岩石圈中水的临界奇异性与断裂耦合触发地震

以等压热容为例,研究岩石圈中水的临界奇异性及出现的条件,探讨岩石圈中水的临界奇异性与断裂耦合作用触发地震的可能性。岩石圈中水存在一、二级相变,相变时水的物理化学性质将发生明显改变,在临界点处表现出奇异性,如热容、膨胀系数和压缩系数等将趋于无穷大,按照Mie-Grneisen方程((P/T)V=γρCV),热容无穷大时将导致热压也趋于无穷大,压力将瞬时剧增。但水的临界奇异性出现的条件是温、压同时趋于临界值,在岩石圈中温、压是相互关联的,按照正常的地温梯度(15～35℃/km)和地压梯度(0.025～0.03GPa/km)计算,达到水的临界温度和压力的深度分别是24～10km和0.88～0.73km,即在岩石圈中若没有断裂的存在时则不可能同时达到水的临界温度和临界压力,不可能出现临界奇异性。断裂使压力降至水的临界压力,使得在岩石圈中某处温度和压力可同时达到水的临界值而出现奇异性,水的临界奇异性和断裂的耦合导致热压剧增,可能触发地震     

Crustal and upper mantle structures of the brazilian coast

The Rayleigh wave phase and group velocities in the period range of 24–39 sec, obtained from two earthquakes which occurred in northeastern brazil and which were recorded by the Brazilian seismological station RDJ (Rio de Janeiro), have been used to study crustal and upper mantle structures of the Brazilian coastal region. Three crustal and upper mantle models have been tried out to explain crustal and upper mantle structures of the region. The upper crust has not been resolved, due basically to the narrow period range of the phase and group velocities data. The phase velocity inversions have exhibited good resolutions for both lower crust and upper mantle, with shear wave velocities characteristic of these regions. The group velocity data inversions for these models have showed good results only for the lower crust. The shear wave velocities of the lower crust (3.86 and 3.89 km/sec), obtained with phase velocity inversions, are similar to that (=3.89 km/sec) found byHwang (1985) to the eastern South American region, while group velocity inversions have presented shear velocity (=3.75 km/sec) similar to that (=3.78 km/sec) found byLazcano (1972) to the Brazilian shield. It was not possible to define sharply the crust-mantle transition, but an analysis of the phase and group velocity inversions results has indicated that the total thickness of the crust should be between 30 and 39 km. The crustal and upper mantle model, obtained with phase velocity inversion, can be used as a preliminary model for the Brazilian coast.