矿物包裹体的气、液相成分测定

矿物中包裹体温度、压力和气、液相成分的测定数据是阐明矿床成因、成矿物质来源、成矿物质化学条件和成矿元素运移方式等的重要地球化学参数。本文介绍了用载气热爆—气相色谱法测定气相成分(H_2、O_2、N_2、CH_4、CO、CO_2、H_2O)和用超声波提取液相成分,再用原子吸收分光光度计法和数字离子计法分别测定阳离子(K~+、Na~+、Ca~(2+)、Mg~(2+))、阴离子(F~-、Cl~-)。对实验装置、工作条件和分析步骤等本文均有叙述。并以石英标样,对实验结果作了初步讨论。其中对气相成分的提取,用载气热爆法代替真空热爆法可提高工作效率五倍。     

粘弹性介质单程波法非零偏移距地震数值模拟与偏移

地震资料分辨率降低,得不到深层介质的精确信息实际上是由于大地吸收效应的影响.同时与双程波动方程相比单程波动方程避免了多次波的干扰并且计算效率高、占用内存少.本文首先基于开尔芬粘弹性介质模型将品质因子与单程波分步傅立叶法波场延拓算子相结合,实现了粘弹性介质波场延拓,从而将单程波弹性介质波场延拓推广到了粘弹性介质.然后在定位原理,数学检波器原理以及等时叠加原理的基础之上实现了粘弹性介质非零偏移距叠前正演模拟.最后将数值模拟得到的正演记录进行弹性偏移和粘弹性偏移并进行对比分析.通过数值算例可以看出,粘弹性介质叠前正演深层的反射波能量减弱,同相轴变粗,频带变窄,主频减小,分辨率降低;粘弹性偏移不但实现了振幅的恢复,而且同时偏移剖面的垂向空间分辨率也得到了提高.     

井间电磁波CT技术在长江大堤岩溶探测中的应用

地下井间电磁波法层析技术（CT）是一门新技术,它将医学CT的原理成功地运用于地学中,依照电磁波在地下有耗介质中传播规律及一定的物理和数学关系,反演透视剖面上的物理参数的分布,最后以图像的形式表现出来。长江大堤武汉段附近的碳酸盐岩地区,由于地势较低和长江水位动态变化,使地下水长期作用于灰岩裂隙,往往使岩溶或破碎带更加发育,形成地下溶洞,给长江大堤和附近的工农业生产、居民生活带来极大的隐患和危险。通过井间电磁波法层析技术共90个电磁波CT剖面测试,发现有28个CT剖面出现异常。此次的探测,为长江大堤周边安全的防治提供可靠精确的地下地质资料。     

半干旱区冬春季黑碳气溶胶吸收特性的观测研究

利用2006年4月和12月锡林浩特观象台黑碳灰度仪的观测资料,分析了半干旱地区黑碳气溶胶浓度的变化特征,讨论了引起这些变化特征的影响因子。结果表明,黑碳气溶胶浓度冬季远大于春季,日变化呈明显的双峰型;讨论了风速对黑碳气溶胶浓度不同影响的范围,可知风速在较小的情况下（小于3.5 m·s-1）,黑碳气溶胶浓度值随风速的增大而减小;在3.5~4.5 m·s-1之间,风速增大,黑碳气溶胶浓度值也增大;风速较大（大于4.5 m·s-1）后,黑碳气溶胶浓度与风速之间没有明显的相关性。冬季12月由于黑碳气溶胶吸收作用造成的消光占总气溶胶消光的25%。     

Mathematical modeling and full-scale shaking table tests for multi-curve buckling restrained braces

Buckling restrained braces(BRBs)have been widely applied in seismic mitigation since they were introduced in the 1970s.However,traditional BRBs have several disadvantages caused by using a steel tube to envelope the mortar to prevent the core plate from buckling,such as;complex interfaces between the materials used,uncertain precision,and time consumption during the manufacturing processes.In this study,a new device called the multi-curve buckling restrained brace (MC-BRB) is proposed to overcome these d...     

谱模拟频谱比法反演品质因子稳定性分析

地震波在粘弹性介质中传播的一个基本特征是能量的衰减及地震波的瞬时波形变化。从广义上说,衰减可分为两类：一类是与地震波传播特性有关的衰减|另一类是反映介质内在属性的地层本征衰减,地层的本征衰减通常用品质因子来度量。反演品质因子的方法有多种,常用的是谱模拟频谱比法。笔者的主要目的是通过模型试算来分析评价该方法在反演品质因子时对干涉和噪声的稳定性,得出有益的结论,用于指导反演计算。     

三乙醇胺增敏火焰原子吸收光谱法测定地质样品中的钼

样品经王水分解,加入适量的三乙醇胺增敏,用空气-乙炔火焰原子吸收光谱法测定地质样品中的钼。选择了三乙醇胺的最佳用量;比较了钼在盐酸-磷酸-铝盐、盐酸-三乙醇胺、盐酸-三乙醇胺-磷酸、盐酸-三乙醇胺-磷酸-铝盐等4种不同介质中的特征浓度。结果表明,在盐酸-三乙醇胺-磷酸-铝盐介质中,钼的质量浓度≤40 mg/L内线性良好,方法检出限为0.2 mg/L,相对标准偏差为5.2%(n=6),加标回收率为96%~102%。对国家一级标准物质进行测定,结果与标准值相符。     

On the H i content, dust-to-gas ratio and nature of Mg ii absorbers

We estimate the mean dust-to-gas ratio of Mg  ii absorbers as a function of rest equivalent width W ₀ and redshift over the range  0.5 < z < 1.4  . Using the expanded Sloan Digital Sky Survey/ Hubble Space Telescope sample of low-redshift Lyman-α absorbers, we first show the existence of a 8σ correlation between the mean hydrogen column density  〈 N _{H  i} 〉  and W ₀, an indicator of gas velocity dispersion. By combining these results with recent dust-reddening measurements, we show that the mean dust-to-gas ratio of Mg  ii absorbers does not appreciably depend on rest equivalent width. Assuming that, on average, dust-to-gas ratio is proportional to metallicity, we find its redshift evolution to be consistent with that of   L ^★  galaxies from   z = 0.5  to 1.4, and we show that our constraints disfavour dwarf galaxies as the origin of such absorbers. We discuss other scenarios and favour galactic outflows from  ∼ L ^★  galaxies as the origin of the majority of strong Mg  ii absorbers. Finally, we show that, once evolutionary effects are taken into account, the Bohlin et al. relation between A _V and N _H is also satisfied by strong Mg  ii systems down to lower column densities than those probed in our Galaxy.     

Properties of warm absorbers in active galaxies: a systematic stability curve analysis

Signatures of warm absorbers are seen in soft X-ray spectra of about half of all type 1 Seyfert galaxies observed and in some quasars and blazars. We use the thermal equilibrium curve to study the influence of the shape of the ionizing continuum, density and the chemical composition of the absorbing gas on the existence and nature of the warm absorbers. We describe circumstances in which a stable warm absorber can exist as a multiphase medium or one with continuous variation in pressure. In particular, we find the following results: (i) the warm absorber exists only if the spectral index of the X-ray power-law ionizing continuum  α > 0.2  and has a multiphase nature if  α∼ 0.8  , which interestingly is the spectral index for most of the observed type 1 Seyfert galaxies; (ii) thermal and ionization states of highly dense warm absorbers are sensitive to their density if the ionizing continuum is sufficiently soft, i.e. dominated by the ultraviolet; (iii) absorbing gas with super-solar metallicity is more likely to have a multiphase nature and (iv) the nature of the warm absorber is significantly influenced by the absence of iron and associated elements which are produced in the later stages of star formation history in Type Ia supernovae.