Protection, Pollution Prevention and Control of Environment in Construction Stage

The proposed Taiwan Strait Tunnel will raise numerous challenges for environmental professionals. The environmental issues must be incorporated in the preliminary study, planning, design, and construction of the works and be addressed consistently throughout all phases of the project. In this article, the environmental issues that will be encountered in the construction stage are discussed, including environmental impact assessment, environmental monitoring, and specific environmental issues during construction such as spoil handling, air quality and noise control, drainage, and health and safety. The experience and practice of handling environmental issues during the construction English Channel Tunnel are reviewed throughout the discussion.     

利用EXCEL软件进行线性回归分析

介绍了EXCEL数据处理软件在一元和多元线性回归分析中的应用方法及实现技巧。     

Fractionation of major elements between coexisting H2O-saturated silicate melt and silicate-saturated aqueous fluids in aluminosilicate systems at 1-2 GPa

From experimental data in the systems Na₂O-Al₂O₃-SiO₂-H₂O, K₂O-Al₂O₃-SiO₂-H₂O at 1100°C, and CaO-Al₂O₃-SiO₂-H₂O at 1200°C in the 1-2 GPa pressure range, the solution behavior of the individual oxides in coexisting H₂O-saturated silicate melts and silicate-saturated aqueous fluids appears to be incongruent. Recalculated on an anhydrous basis, in the CaO-Al₂O₃-SiO₂-H₂O system, CaO^fluid/CaO^melt < 1, whereas in the Na₂O-Al₂O₃-SiO₂-H₂O and K₂O-Al₂O₃-SiO₂-H₂O systems, K₂O^fluid/K₂O^melt and Na₂O^fluid/Na₂O^melt both are greater than 1. The aqueous fluids are depleted in alumina relative to silicate melt.In the Na₂O-Al₂O₃-SiO₂-H₂O, K₂O-Al₂O₃-SiO₂-H₂O, and CaO-Al₂O₃-SiO₂-H₂O systems, fluid/melt partition coefficients for the individual oxides range between ∼0.005 and 0.35 depending on oxide, bulk composition and pressure. The alkali partition coefficients are about an order of magnitude higher than that of CaO. Alumina and silica partition coefficient values in the CaO-Al₂O₃-SiO₂-H₂O system are 10-20% of the values for the same oxides in the Na₂O-Al₂O₃-SiO₂-H₂O and K₂O-Al₂O₃-SiO₂-H₂O systems.Positive correlations among individual partition coefficients and oxide concentrations in the aqueous fluids are consistent with complexing in the fluid that involves silicate polymers associated with alkalis and alkaline earths and aluminosilicate complexes where alkalis and alkaline earths may serve to charge-balance Al³⁺, which is, perhaps, in tetrahedral coordination. Alkali aluminosilicate complexes in aqueous fluid appear more stable than Ca-aluminosilicate complexes.     

我国干旱区洪水灾害基本特征：以新疆为例

依据新疆自然和社会环境,分析了新疆洪水及其洪灾的形成,季节分布,年际变化,地区分布等主要特征,并提出对洪水灾害的防御对策。     

21cm波段ms级太阳射电爆发形态分析

本文利用10米天线上21cmms级连续无间隙快速记录系统,在第22周太阳峰年期间观测到大量的分米波段的太阳射电尖峰辐射的快速活动资料,对这些资料进行分析、比对发现尖峰辐射的快速活动至少包括：毛刺型、缓变型、缓变脉冲型、脉冲型、开关型．同时也对太阳射电尖峰辐射与其它共生现象进行分析,并对尖峰辐射的形态进行了简单的讨论．     

沙尘暴形成史初步研究——中国沙漠几个典型地质学记录的实证

以位于沙漠黄土边界带的榆林、阿羌和米浪沟湾地层剖面为典型例证 ,讨论了 110 0kaBP以来中国沙漠沙尘暴的形成、发展和演化过程。提出在过去的 110 0ka中该区总共记录了 4 2个沙尘暴时期 ,并与 4 1个间沙尘暴时期构成比较连续且交替进行的一系列沉积演化历史。其中 ,最强烈的沙暴期发生时间大致在 6 2 0kaBP和 6 80kaBP前后 ,最温暖的间沙尘暴期出现在 5 90～ 5 0 0kaBP和15 0～ 70kaBP。研究认为 ,110 0kaBP以来因沙尘暴期与间沙尘暴期交替出现而形成的沉积旋回 ,是自那时以来在冰期、间冰期气候波动影响下冬夏古代季风相互对峙、交替演化形成气候旋回的结果     

Ordovician metagranitoid from the Anatolide‐Tauride Block,northwest Turkey: geodynamic implications

We report a Middle Ordovician metagranitoid from the northern margin of the Anatolide‐Tauride Block, the basement of which is generally characterized by voluminous Latest Proterozoic to Early Cambrian granitoids. The Ordovician metagranitoid forms an ～400‐m‐thick body in the marbles and micaschists of the Tav?anl? Zone. The whole sequence was metamorphosed in the blueschist facies during the Late Cretaceous (c. 80 Ma). Zircons from the metagranitoid give a Middle Ordovician Pb‐Pb evaporation age of 467.0 ± 4.5 Ma interpreted as the age of crystallization of the parent granitic magma. The micaschists underlying the metagranitoid yield Cambro‐Ordovician (530–450 Ma) and Carboniferous (c. 310 Ma) detrital zircon ages indicating that the granitoid is a pre‐ or syn‐metamorphic tectonic slice. The Ordovician metagranitoid represents a remnant of the crystalline basement of the Anatolide‐Tauride Block and provides evidence for Ordovician magmatism at the northern margin of Gondwana. Prismatic Carboniferous detrital zircons in the micaschists indicate that during the Triassic, the northern margin of the Anatolide‐Tauride Block was close to Variscan terranes.     

The dependence of quasar variability on black hole mass

In order to investigate the dependence of quasar variability on fundamental physical parameters like black hole mass, we have matched quasars from the Quasar Equatorial Survey Team, Phase 1 (QUEST1) variability survey with broad-lined objects from the Sloan Digital Sky Survey. The matched sample contains ≈100 quasars, and the Sloan spectra are used to estimate black hole masses and bolometric luminosities. Variability amplitudes are measured from the QUEST1 light curves. We find that black hole mass correlates with several measures of the variability amplitude at the 99 per cent significance level or better. The correlation does not appear to be caused by obvious selection effects inherent to flux-limited quasar samples, host galaxy contamination or other well-known correlations between quasar variability and luminosity/redshift. We evaluate variability as a function of rest-frame time lag using structure functions and find further support for the variability–black hole mass correlation. The correlation is strongest for time lags of the order of a few months up to the QUEST1 maximum temporal resolution of ≈2 yr, and may provide important clues for understanding the long-standing problem of the origin of quasar optical variability. We discuss whether our result is a manifestation of a relation between characteristic variability time-scale and black hole mass, where the variability time-scale is typical for accretion disc thermal time-scales, but find little support for this. Our favoured explanation is that more massive black holes have larger variability amplitudes, and we highlight the need for larger samples with more complete temporal sampling to test the robustness of this result.     

2000-2012年中国北方草地NDVI和气候因子时空变化

利用2000-2012年的MODIS NDVI数据,结合中国北方187个气象基准站年均温度和年降水量资料,对2000-2012年中国北方草地NDVI的时空变化特征和同期年均温度、降水量动态变化进行了分析。结果表明:(1)草地NDVI无明显变化的区域占北方草地总面积的64.35%,以荒漠草地为主;草地退化区域的面积(占北方草地总面积的23.97%)大于改善区域的面积(占北方草地11.68%)。(2)NDVI变异系数分析结果表明,2000-2012年以来中国北方草地68.37%区域呈稳定状态。其中,荒漠草地植被变异性较小,处于相对稳定状态的草地占其总面积的79.73%;而灌丛草地和典型草地的变异性较大,变化显著的草地分别占其草地面积的41.55%和45.92%。(3)北方草地区中,54.04%的区域年均温度呈升高趋势,大于温度呈降低趋势的区域,温度升高幅度最大为0.159 ℃·a^-1;年降水量呈增加趋势的面积达71.01%,远大于呈减少趋势的面积,降水量增加的最大幅度为23.29 mm·a^-1。