Seismic microzonation for Penang using geospatial contour mapping

Shear wave velocity (V _s) and the fundamental site period of the subsurface condition are the primary parameters that affect seismic soil amplification in particular sites. Within the topmost layer of the soil, which measures 30 m, the average shear wave velocity V _s30 is commonly used to build codes for site classification for the design of earthquake-resistant structures and to conduct microzonation studies. In this study, the development of a microzonation map for V _s30 distribution, National Earthquake Hazard Reduction Program V _s30 site classification, and a fundamental site period for Penang are presented. The multichannel analysis of surface wave (MASW) test was conducted for more than 50 sites with available borehole data to develop the microzonation maps. The ten selected V _s profiles measured by MASW show a good correlation with the data obtained using empirical correlations in a previous study. The highest V _s values were identified at the northeastern and southeastern parts of Penang Island, corresponding to the shallow bedrock and the outcrop zone. Conversely, the lowest V _s values were found in the northwestern and southwestern parts of the Penang mainland owing to the thick layer of soft clay and silt deposits. The site period map shows the variation in site periods, with the highest value of 1.03 s at the western part of the Penang mainland and the lowest value of 0.02 s at the eastern part of the Penang Island. The microzonation maps developed in this study are vital to studies on seismic hazard and earthquake mitigation programs in Malaysia.     

Toxicity assessments of nanoscale zerovalent iron and its oxidation products in medaka (Oryzias latipes) fish

Iron-based nanotechnologies are increasingly used for environmental remediation; however, toxicologic impacts of iron nanoparticles on the aquatic ecosystem remain poorly understood. We treated larvae of medaka fish (Oryzias latipes) with thoroughly characterized solutions containing carboxymethyl cellulose (CMC)-stabilized nanoscale zerovalent iron (nZVI), aged nanoscale iron oxides (nFe-oxides) or ferrous ion (Fe[II]) for 12-14 days' aqueous exposure to assess the causal toxic effect(s) of iron NPs on the fish. With the CMC-nZVI solution, the dissolved oxygen level decreased, and a burst of reactive oxygen species (ROS) was generated as Fe(II) oxidized to ferric ion (Fe[III]); with the other two iron solutions, these parameters did not significantly change. CMC-nZVI and Fe(II) solutions caused acute lethally and sublethally toxic effects in medaka larvae, with nFe-oxide-containing solutions causing the least toxic effects. We discuss modes of toxic action of iron NPs and chronic toxic effects in terms of hypoxia, Fe(II) toxicity and ROS-mediated oxidative damage.     

大地电磁全信息资料三维共轭梯度反演研究(英文)

在对张量阻抗数据、倾子数据和共轭梯度算法深入分析的基础上,我们实现了大地电磁全信息资料三维共轭梯度反演算法。基于全信息资料的三维共轭梯度反演研究,探讨了同时利用五个电磁场分量整理得到的大地电磁资料进行三维反演定量解释的方法以及全信息数据在三维反演中的作用。理论模型合成数据的反演结果表明,在三维反演中使用张量阻抗和倾子数据结合的全信息数据的反演结果优于只使用张量阻抗数据(或只使用倾子数据)的反演结果,提高了反演结果的分辨率和可信度。合成数据的反演算例也验证了所实现的大地电磁全信息资料三维共轭梯度反演算法的正确性和稳定性。     

藤田公式改进及其在台风预报中的应用

在考虑环境气压的影响下,引进环境半径参量对藤田公式改进并将其应用到9711号台风研究预报中.结果表明:①改进的藤田公式能够基本解决藤田公式计算的外围气压和气压梯度偏小这一问题,合理地给出整个台风域内气压和气压梯度力的分布.②改进的藤田公式由于引入了环境半径的影响,使得计算的风向内偏角减小而风速增大;特别是它能使台风外围...     

高空业务新规范和新质量考核办法意义的延伸

通过新、旧规范和质量考核办法的比较,发现新规范和新质量考核办法的变更重点．联系高空业务现状．通过分析,探讨其意义的延伸。     

Geochemistry and origin of rare earth elements (REEs) in the Shengli River oil shale, northern Tibet, China

The Shengli River-Changshe Mountain oil shale zone, located in the North Qiangtang depression, northern Tibet plateau, represents a potentially large marine oil shale resource in China. Twenty-eight samples including oil shale, micritic limestone and marl were collected from the Shengli River area to determine the contents and distribution patterns of rare earth elements (REEs) in marine oil shale. Oil shale samples from the Shengli River area have high ash yield (61.86–67.48%) and TOC content (8.02–13.67%) with low total sulfur (S_t,d) content (0.76–1.39%) and intermediate shale oil content (3.60–16.30%). The total rare earth element (ΣREE) content in oil shale samples is notably depleted (46.79–67.90 μg/g), approximately one third of the mean value of the North American Shale Composite (NASC), and lower than that of world-wide black shales and Chinese coals, but higher than that of world-wide coals and micritic limestone samples (29.21 μg/g) from the Shengli River area. The oil shale samples from the Shengli River area exhibit shale-like Chondrite or NASC-normalized REE patterns similar to those of micritic limestone and marl samples from this area, indicating that REEs of these different lithological samples may have been derived from a similar terrigenous source.REE contents of oil shale samples are highly positive correlated with ash yield and show a positive correlation with Fe and a weakly positive correlation with organic sulfur, and the vertical variations of REEs mainly follow those of Si, Al, K and Ti. All these facts indicate that the REE contents in oil shale seams are mainly controlled by clay minerals and, to a lesser extent, by pyrite, as well as partly associated with oil shale organic constituents. Rare earth elements in the Shengli River oil shale have originated from two sources: a felsic volcanic rock source and a clastic or/and limestone source.     

Studies on the solid acidity of heated and cation-exchanged montmorillonite using n-butylamine titration in non-aqueous system and diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy

The effects of heating and cation exchange on the solid acidity of montmorillonite were investigated using n-butylamine titration in non-aqueous system and diffuse reflectance Fourier transform infrared spectroscopy. The number of total, Brønsted, and Lewis acid sites showed the same modulation tendency with increasing heating temperature, reaching a maximum at 120 °C and subsequently decreasing until it reaches a minimum at 600 °C. The Lewis acid sites result from unsaturated Al³⁺ cations, and their number increased with the heating temperature due to the dehydration and dehydroxylation of montmorillonite. The generation and evolution of Brønsted acidity were mainly related to interlayer-polarized water molecules. Water adsorbed on the unsaturated Al³⁺ ions also acted as a Brønsted acid. The acid strength of the Brønsted acid sites was dependent on the polarization ability of the exchangeable cation, the amount of interlayer water, and the degree of dissociation of the interlayer water coordinated to exchangeable cations. All cation-exchanged montmorillonites exhibited different numbers of acid sites and various distributions of acid strength. Brønsted acidity was predominant in Al³⁺-exchanged montmorillonite, whereas the Na⁺- and K⁺-exchanged montmorillonites showed predominantly Lewis acidity. Moreover, Mg²⁺- and Li⁺-exchanged montmorillonites exhibited approximately equal numbers of Brønsted and Lewis acid sites. The Brønsted acidity of cation-exchanged montmorillonite was positively correlated with the charge-to-radius ratios of the cations, whereas the Lewis acidity was highly dependent on the electronegativity of the cations. The acid strengths of Al³⁺- and Mg²⁺-exchanged montmorillonites were remarkably higher than those of monovalent cation-exchanged montmorillonites, showing the highest acid strength (H ₀ ≤ ?3.0). Li⁺- and Na⁺-exchanged montmorillonites exhibited an acid strength distribution of ?3.0 < H ₀ ≤ 4.8, with the acid strength ranging primarily from 1.5 to 3.3 in Li⁺-exchanged montmorillonite, whereas only weaker-strength acid sites (1.5 < H ₀ ≤ 4.8) were present in K⁺-exchanged montmorillonite. The results of the catalysis experiments indicated that montmorillonite promoted the thermal decomposition of the model organic. The catalytic activity showed a positive correlation with the solid acidity of montmorillonite and was affected by cation exchange, which occurs naturally in geological processes.     

Fractionation of hydrogen and oxygen isotopes of gypsum hydration water and assessment of its geochemical indications

Fundamental knowledge of the isotopic fractionation between the hydration water and the mother solution and whether the primary information recorded in hydration water can be preserved or not in deposits or mines have long been unclear. In order to calculate the accurate hydrogen and oxygen isotopic fractionation factors between gypsum hydration water and its mother solution with new methods, to understand the mechanism of fractionation and synthetically assess the record-keeping abilities of the isotopic composition of hydration water during the process of diagenesis after deposition, experiments on the hydrogen and oxygen isotopic compositions of gypsum hydration water and its mother solution at different isothermal temperatures from 5 to 50°C were systematically conducted. In addition, samples from two typical gypsum deposits formed in different environmental conditions were also determined. Results show that during gypsum crystallisation, both hydrogen and oxygen isotopes show significant fractionation between the hydration water and the mother solution. The calculated hydrogen isotopic fractionation factors are <1, while the oxygen isotopic fractionation factors are >1 at temperatures from 5 to 50°C. The fractionation factors show no functional relationships with temperature. Isotopic compositions of gypsum hydration water in arid lake sediments can be used to trace the source of water and primary deposit environmental information. However, the isotopic composition of the gypsum hydration water can easily be altered by dissolution and secondary precipitation of gypsum during later diagenesis, particularly in areas with humid climate and abundant groundwater. A very careful assessment on record-keeping abilities of the primary isotopic composition of hydration water in gypsum during later diagenesis must be considered before application.     

中国北方沙漠/沙地锆石形态特征及其对物源的指示

单颗粒锆石的形态、颜色等特征记录了其母岩结晶过程的温度、压力、结晶介质的化学性质等信息,鉴定不同沙漠/沙地碎屑锆石的晶体形态特征可以指示沉积物的原岩类型,进而可以帮助追溯物源.本文分析了中国北方塔克拉玛干沙漠、巴丹吉林沙漠、腾格里沙漠、毛乌素沙地、浑善达克沙地、科尔沁沙地等6个沙漠/沙地36个地表样品的碎屑锆石形态特征.结果显示,同一沙漠/沙地样品锆石形态特征较为一致,而不同沙漠/沙地样品锆石形态有差异.塔克拉玛干沙漠锆石多为无色或淡紫色,包裹体较少,锆石颗粒锥面较发育,短柱状锆石含量较多,指示该沙漠物质主要来自其北缘天山山脉早中生代碱性花岗岩.巴丹吉林沙漠和腾格里沙漠锆石形态特征较类似,相比较而言巴丹吉林沙漠锆石多为淡粉色,形态上锥面较发育,较少见到包裹体;而腾格里沙漠锆石颗粒细长柱较多和含包裹体颗粒较多,这两个沙漠物质可能来自其南部中央造山带的变质岩和其北缘中亚造山带早中生代碱性花岗岩.毛乌素沙地多为深色、锥面发育和短柱状颗粒锆石较常见,含包裹体颗粒较多,该沙地物质主要来自其西北孔兹岩带以及北部阴山山脉碱性花岗岩.浑善达克沙地锆石形态似毛乌素沙地,指示其物源与毛乌素沙地类似.科尔沁沙地锆石磨蚀严重,扁柱状锆石颗粒较常见,指示该沙地物质大部分来自其南缘燕山山脉的显生宙浅海沉积岩.本研究表明碎屑锆石形态特征可以指示沙漠或沙地沉积物的源区.     

风暴潮灾害风险评估研究综述

我国是受风暴潮影响最严重的少数国家之一,风暴潮灾害致灾机理的研究在过去几十年取得了极大的进展,而风暴潮脆弱性评估和综合风险评估还不能满足风暴潮灾害风险管理的需求.系统总结了风暴潮危险性、脆弱性、综合风险评估及其应用的研究进展,重点分析了典型重现期风暴潮估计、可能最大风暴潮计算、风暴潮物理脆弱性和社会脆弱性评估以及风暴潮风险评估及其应用的研究进展及不足,并对我国风暴潮风险评估急需解决的问题以及未来的研究重点进行了展望,指出了风暴潮灾害风险评估的模型化、系统化、定量化是未来风暴潮风险评估研究的发展趋势,风暴潮灾害的未来风险评估还需考虑全球气候变化以及海平面上升等因素的影响,而风暴潮灾害承灾体脆弱性的定量评价是风暴潮综合风险评估的重点和难点.