饱和烃经5à分子筛络合前后单体烃碳同位素分析对比研究

通过对自配标准样品(正构烷烃)进行5à分子筛吸附试验,测定了用5分子筛吸附法分离前后正构烷烃、异构烷烃和环烷烃碳同位素值,探讨试验前后碳同位素值的变化。尽管实验过程中样品经过85℃长时间加热回流及吸附样品的5à分子筛用氢氟酸酸化处理,但实验结果经仪器检测,证明该方法对正构烷烃碳同位素值影响因素不大。本文还介绍了原油和煤可溶有机质中饱和烃络合前后的单体烃碳同位素分析方法。并在前人工作的基础上,改进采用微型索氏抽提加热回流实验装置,既提高了样品的回收率,也减少了样品中轻组分的损失。     

Soluble organic compounds in fog and cloud droplets: what have we learned over the past few years?

We have recently set up a new procedure for characterising the water soluble organic compounds (WSOC) in fog water, for which information is still rather limited. Fog samples collected during the 1998–1999 fall–winter season in the Po Valley (Italy) were analysed following this procedure, which allows a quantitative determination of three main classes of organic compounds (neutral species, mono- and di-carboxylic acids, polycarboxylic acids), together accounting for ca. 85% of the total WSOC. This procedure also provides information on the main chemical characteristics of these three classes of compounds (functional groups, aliphatic vs. aromatic character, etc.). The enhanced chemical knowledge on fog/cloud chemical composition opens new scenarios as far as chemical and microphysical processes in clouds and fogs are concerned.     

福建福安下白石特大桥海上岩土勘察方法

下白石特大桥是同江至三亚国道主干线福鼎至宁德高速公路建设中的一项控制性工程 ,是交通部指定的三阶段设计工程 ,桥长 110 5 m,主跨采用 2× 2 6 0 m预应力混凝土连续钢构。桥位位于白马河入海口处 ,工程地质、水文地质条件复杂 ,通过采用地表大面积的综合地质调查、海上地震映像物探以及海上钻探、原位测试、岩土测试等一系列行之有效的岩土勘察方法 ,确保了岩土工程勘察质量 ,其结果切实可行 ,为后期施工单位提供科学依据。     

加水热模拟中深湖与煤系泥岩地化特征比较

通过深湖泥岩和煤系泥岩的加水热模拟研究认为,在热模拟实验过程中,深湖泥岩和煤系泥岩显示不同特征,并且其演化有差别。深湖泥岩利于液态原油的生成,并且转化率高于煤系泥岩。深湖泥岩残余可溶有机质饱和烃含量高于煤系泥岩,非烃含量则低于煤系泥岩。深湖泥岩胶质 /沥青质和饱芳比均随温度升高而降低,而煤系泥岩的胶质 /沥青质随温度升高有增加趋势,其饱芳比的变化则不大或有降低趋势。深湖泥岩的T_max难以指示演化阶段,其干酪根碳同位素值明显轻于煤系泥岩,它们的值均随温度的升高而变重。     

Constraints on the application of carbon isotope thermometry in high- to ultrahigh-temperature metamorphic terranes

Nine marble horizons from the granulite facies terrane of southern India were examined in detail for stable carbon and oxygen isotopes in calcite and carbon isotopes in graphite. The marbles in Trivandrum Block show coupled lowering of δ¹³C and δ¹⁸O values in calcite and heterogeneous single crystal δ¹³C values (? 1 to ? 10‰) for graphite indicating varying carbon isotope fractionation between calcite and graphite, despite the granulite facies regional metamorphic conditions. The stable isotope patterns suggest alteration of δ¹³C and δ¹⁸O values in marbles by infiltration of low δ¹³C–δ¹⁸O‐bearing fluids, the extent of alteration being a direct function of the fluid‐rock ratio. The carbon isotope zonation preserved in graphite suggests that the graphite crystals precipitated/recrystallized in the presence of an externally derived CO₂‐rich fluid, and that the infiltration had occurred under high temperature and low f_O2 conditions during metamorphism. The onset of graphite precipitation resulted in a depletion of the carbon isotope values of the remaining fluid+calcite carbon reservoir, following a Rayleigh‐type distillation process within fluid‐rich pockets/pathways in marbles resulting in the observed zonation. The results suggest that calcite–graphite thermometry cannot be applied in marbles that are affected by external carbonic fluid infiltration. However, marble horizons in the Madurai Block, where the effect of fluid infiltration is not detected, record clear imprints of ultrahigh temperature metamorphism (800–1000 °C), with fractionations reaching <2‰. Zonation studies on graphite show a nominal rimward lowering δ¹³C on the order of 1 to 2‰. The zonation carries the imprint of fluid deficient/absent UHT metamorphism. Commonly, calculated core temperatures are > 1000 °C and would be consistent with UHT metamorphism.     

云南腾冲地块北部空树河组一个菱铁矿结核中的C、O同位素变化特征

空树河组是滇西腾冲地块北部的石碳－二叠纪冈瓦纳相沉积。菱铁矿结核见于该组顶部的黑色泥岩中。将一个结核通过中心切开，在切面上由中心向边缘用牙钻等间隔提取10个样品。同位素测试结果显示，δ^13C自中心向边缘逐渐由－8．09％减为－16．12％，最外一个样例外（－15．39‰），而δ^18O自中心向边缘逐渐由－10．64‰增加为0‰左右。δ^13C的变化情况表明，菱铁矿结核可能形成于硫酸盐还原带。在解释δ^18o的变化情况时，推测在结核开始生长时可能有δ^18O亏损的大气降水掺入，随着埋藏深度的逐渐加大，孔隙水的O同位素逐渐趋近正常海水的值（0‰）。     

软基上高速铁路路桥过渡段的技术措施研究

通过对高速铁路路基与桥梁过渡段动力特性分析，指出结构物沉降差是导致轨面不平顺的主要因素。分析了沉降差产生的原因，提出了软基上路桥过渡段的结构设计方案，并对其施工方法及质量检测标准进行了探索。     

Study on Paleoenvironment since Late Glacial Eooch in Lanzhou Area, China

The Hongzuisi Section in Lanzhou area is used to infer the paleoclimate since the late glacial epoch. Through combined analysis of organic carbon isotope and CaCO3 content, paleoenvironment evolution of Hongzuisi Section since the late glacial epoch is discussed. There were changes in both drymoist and warm-cold. Especially the climate changes can be compared with synchronous sections of other areas, which provides useful information for our future forecast.     

Impact of oasis establishment on underground environment in salinized sandy lands

The salinized sandy lands are the important reclaimable reserve wastelands in thesouth area of the Xinjiang Uygur Autonomous Region of China. But it is necessary that the eco-logical environment of the area is not destroyed by action of oasis development. The main factor tohinder oasis development is land salinization. Rational oasis establishment rebuilds wastelandswith lower productivity and utilization efficiency for the growth of agriculture, forestry, and stock raising. The results of surveying sub-soil environment of Aimugaike. Awati oasis in Hotian County ofthe Xinjiang Uygur Autonomous Region show that the underground water and soil environment arenot deteriorated under the rational management and administration, which could be coordinatedfor obtaining economic and environmental benefit. During the oasis establishment period from1997 to 1999, the plowland area has reached 166.7 hm2, and the seed cotton yield per unit areahas reached 2250 kg @ hm-2, the area of timber forest and active sand break forest has reached 20hm2, the area of fruit trees is 71.5 hm2; and the soil moisture has decreased from 22.07% to18.12%. In the first year of oasis establishment, the soil type has changed salt soil into light saltsoil, in the second year the soil has been out of salt harm; and the content of soil organic matter intopsoil has increased obviously.     

液化场地桩-土-桥梁结构动力相互作用振动台试验研究进展

本文在全面归纳与总结液化场地桩－土－桥梁结构动力相互作用振动台试验及与之相关领域的国内外研究进展基础上，直接针对我国桥梁工程中的主要震害问题，提出在我国开展液化场地桩－土－桥梁结构动力相互作用振动台试验研究的必要性，并阐述作者对液化场地桩－土－张桥梁结构动力相互作用振动台试验中若干问题的认识。