Characteristics of Light Transmission in Summer and Winter and Its Relation to Sediment Transport in the East China Sea

INTRODUCTIONTheSubeiShoalandtheChangjiangRiverestuarineareainthewestoftheHuanghaiandEastChinaSeasisoneofthemarginalseasintheworld ,wheresuspendedmatterisextremelyhigh .Here ,notonlyistheretheTaiwanWarmCurrentoneoftheKuroshio’sbranchesintheEastChinaSea,butalsotheHuanghaiCoastalCurrent,andChangjiangDilutedWater.Sothestrongmixingbetweenthecoastalandoffshorewaterscomplicatessuspendedmatterdistributioninthisarea.HowthesuspendedmatterdischargedfromtheChangjiangRiverandtheabandonedHuan…     

A note on the algorithm of symplectic integrators

For a Hamiltonian that can be separated into N+1(N\geq 2) integrable parts, four algorithms can be built for a symplectic integrator. This research compares these algorithms for the first and second order integrators. We found that they have similar local truncation errors represented by error Hamiltonian but rather different numerical stability. When the computation of the main part of the Hamiltonian, H ₀, is not expensive, we recommend to use S ^* type algorithm, which cuts the calculation of the H ₀ system into several small time steps as Malhotra(1991) did. As to the order of the N+1 parts in one step calculation, we found that from the large to small would get a slower error accumulation. This revised version was published online in July 2006 with corrections to the Cover Date.     

单片机在卫星天线控制系统中的应用

主要介绍卫星天线控制系统中天线旋转定位控制的软硬件设计和实现。该部分的主要功能是：接收红外遥控器的信号；检测前面板上的按键信号；检测传感器反馈的信号；根据所得信号作出相应的动作。     

Age-metallicity relation for F-stars

We derived the age-metallicity relation for the solar neighbourhood from theuvby, H photometry of F-stars using the evolutionary models of Hejlesen (1980). It is shown that disk formation is divided into two phases according to the fast and slow collapse which accompany the initial rapid enrichment and slow increase of the metallicity of the galactic disk, respectively.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.     

Timing of the Nihewan formation and faunas

Magnetostratigraphic dating of the fluvio-lacustrine sequence in the Nihewan Basin, North China, has permitted the precise timing of the basin infilling and associated Nihewan mammalian faunas. The combined evidence of new paleomagnetic findings from the Hongya and Huabaogou sections of the eastern Nihewan Basin and previously published magnetochronological data suggests that the Nihewan Formation records the tectono-sedimentary processes of the Plio-Pleistocene Nihewan Basin and that the Nihewan faunas can be placed between the Matuyama-Brunhes geomagnetic reversal and the onset of the Olduvai subchron (0.78-1.95 Ma). The onset and termination of the basin deposition occurred just prior to the Gauss-Matuyama geomagnetic reversal and during the period from the last interglaciation to the late last glaciation, respectively, suggesting that the Nihewan Formation is of Late Pliocene to late Pleistocene age. The Nihewan faunas, comprising a series of mammalian faunas (such as Maliang, Donggutuo, Xiaochangliang, Banshan, Majuangou, Huabaogou, Xiashagou, Danangou and Dongyaozitou), are suggested to span a time range of about 0.8-2.0 Ma. The combination of our new and previously published magnetostratigraphy has significantly refined the chronology of the terrestrial Nihewan Formation and faunas.     

激光拉曼光谱法分析多种显微组分荧光变化及其应用

利用激发488 nm激光的氩离子激光器作为RENISHAW inVia型激光拉曼光谱仪的光源,建立了多种显微组分荧光变化(FAMM)分析方法,并对镜质体反射率明显抑制的东营凹陷有效烃源岩进行了测定。结果表明,东营凹陷有效烃源岩的有机质类型越好,镜质体反射率抑制程度越高,有效烃源岩的真实成熟度应主要处于0.64%~1.30%,而不是实测镜质体反射率所反映的0.37%~1.10%。     

An experimental study of the grain-scale processes of peridotite melting: implications for major and trace element distribution during equilibrium and disequilibrium melting

The grain-scale processes of peridotite melting were examined at 1,340°C and 1.5 GPa using reaction couples formed by juxtaposing pre-synthesized clinopyroxenite against pre-synthesized orthopyroxenite or harzburgite in graphite and platinum-lined molybdenum capsules. Reaction between the clinopyroxene and orthopyroxene-rich aggregates produces a melt-enriched, orthopyroxene-free, olivine + clinopyroxene reactive boundary layer. Major and trace element abundance in clinopyroxene vary systematically across the reactive boundary layer with compositional trends similar to the published clinopyroxene core-to-rim compositional variations in the bulk lherzolite partial melting studies conducted at similar P–T conditions. The growth of the reactive boundary layer takes place at the expense of the orthopyroxenite or harzburgite and is consistent with grain-scale processes that involve dissolution, precipitation, reprecipitation, and diffusive exchange between the interstitial melt and surrounding crystals. An important consequence of dissolution–reprecipitation during crystal-melt interaction is the dramatic decrease in diffusive reequilibration time between coexisting minerals and melt. This effect is especially important for high charged, slow diffusing cations during peridotite melting and melt-rock reaction. Apparent clinopyroxene-melt partition coefficients for REE, Sr, Y, Ti, and Zr, measured from reprecipitated clinopyroxene and coexisting melt in the reactive boundary layer, approach their equilibrium values reported in the literature. Disequilibrium melting models based on volume diffusion in solid limited mechanism are likely to significantly underestimate the rates at which major and trace elements in residual minerals reequilibrate with their surrounding melt. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Simple models for dynamic melting in an upwelling heterogeneous mantle column: Analytical solutions

Several lines of evidence suggest that the melt generation and segregation regions of the mantle are heterogeneous, consisting of chemically and lithologically distinct domains of variable size and dimension. Partial melting of such heterogeneous mantle source regions gives rise to a diverse range of basaltic magmas. In order to better assess the role of source heterogeneity during mantle melting, we have undertaken a theoretical study of trace element distribution and fractionation during concurrent melting and melt migration in an upwelling, chemically heterogeneous, two-porosity double lithology melting column. Analytical solutions for the abundance of a trace element in the matrix and channel were obtained under the assumptions that the porosity, melt and solid velocities, and solid-melt partition coefficients are constant and uniform. For simplicity, we neglected diffusion and dispersion in the melt. Chemical source heterogeneities of arbitrary size and shape were integrated into the simple melting models by allowing trace element abundance in the source region to vary as a function of time and space. Concurrent melting and melt migration in an upwelling heterogeneous mantle may be approximated as a quasi-steady state problem in which time-dependent concentration patterns produced by melting of heterogeneous source regions are superimposed on a reference steady-state concentration distribution established by melting of the ambient or background mantle. Chromatographic fractionation is especially important for the matrix melt and solid when chemical heterogeneities are involved during melting and melt migration in the mantle, giving rise to significant phase-shift between two incompatible trace elements in the matrix melt and scattered correlations among incompatible trace elements in residual peridotites. Mixing is the chief mass transfer process in the dunite channel where the chromatographic effect is negligible for most of the incompatible trace elements. The lack of chromatographic fractionation among incompatible trace elements and isotopic ratios in MORB suggests either most MORB are channel melts or mixing in magma conduit and chamber is very efficient such that the phase-shift is averaged out during magma transport and storage processes. Advection brings melt produced by smaller-degree of melting in the deeper part of the melting column to the overlying melting region, increasing the incompatible trace element abundance in the matrix and the channel. This advection-induced self-enrichment is especially important when heterogeneous sources are involved and may account for some of the enriched incompatible trace element patterns observed in residual peridotite that were previously interpreted to be a result of mantle metasomatism. Systematic studies of high-resolution spatially correlated mantle samples may help to constrain the melting history and the size and nature of chemical heterogeneities in the mantle.     

等温微量热法在土壤微生物研究方面的进展

土壤微生物是陆地生态系统中分解者亚系统的主要组成部分, 参与了包括有机质降解、营养转化、 植物生长的促进或抑制以及各种土壤物理过程在内的一系列反应活动. 土壤微生物则是土壤质量重要的生物指标, 可以用来监控土壤质量的变化. 等温微量热法是一种简便、快速地测量微生物活性的方法, 在土壤微生物代谢热效应的研究领域中广泛应用. 就等温微量热法在土壤微生物活性中的研究进展进行综述: 等温微量热法的简介, 微量热方法与传统方法的比较, 等温微量热法在各种外界环境和土壤条件影响下的土壤微生物活性研究中的应用, 并对等温微量热法在土壤微生物和其它方面的研究进行了展望.     

川西108国道高位崩塌成因与运动特征

2007年5月25日于川西108国道某段发生的高位崩塌造成了重大人员伤亡和财产损失。综合地质调查、三维激光扫描技术、爆破振动效应分析以及历史崩塌与降雨关系的统计分析,得出了地形高陡、岩体破碎及降雨诱发等是崩塌产生的主要原因,爆破振动对其也有轻微间接影响。根据边坡形态及塌落高度,运用运动学原理及能量法还对崩塌体的撞击速度及冲击力进行了计算分析。