伴生金赋存状态的几种主要研究方法

作者总结了在多年研究伴生金赋存状态中常采用的光学显微镜法、电子探针分析法、元素的化学分析法、选择性溶解法及元素平衡配分法等几种有效的研究方法,并给出一些应用的例子.通过这些研究方法,能够有效、快捷地查清伴生金的赋存状态特征及分布规律,为今后的研究提供可借鉴的经验.     

Tracing infiltration and recharge using stable isotope in Taihang Mt., North China

The groundwater in headwater region is an important recharge source for the adjacent mountain-front plain. In order to reveal the relationship among precipitation, soil water and groundwater, from June to September in 2004, stable isotopes (deuterium and oxygen-18) in precipitation and soil waters at the depths of 10, 20, 30, 50, 70, 90, and 110 cm were analyzed at two sites covered by black locust (Robinia Pseudoacia L.) (Site A) and grass predominated by Themeda triandra (T. japonica (Willd.) Tanaka) and Bothriochloa ischaemum (B. ischaemum (L.) Keng) (Site B) in an experimental catchment at Taihang Mt., North China, respectively. The δ¹⁸O of precipitation in daily rain events shows large variations (−13.3 to −4.3‰) with a mean of 8.1‰. The δ¹⁸O and δ D of soil waters along profiles in two sites suggest that the influence of canopy cover was just up to 10 cm in top soil water. The soil water moved over the zero flux plane at 70 cm in-depth is expected to escape the evaporative effect at the end of September in both sites. The results show that the stable isotope, instead of tritium as tradition, can be used to trace the soil water behaviors based on the movement of isotopic peak along the vertical profiles in this semi-arid and semi-humid mountainous region. The infiltration depths of soil water in Taihang Mt. are 12 and 10 mm/day from June to September in 2004 in Site A and Site B, respectively. Tracing by stable isotope, recharge fluxes of soil water to local groundwater are of 3.8 and 3.2 mm/day in Site A and Site B, respectively. The results provide desirable information for assessment of local groundwater resources. An erratum to this article can be found at     

江西安远路迳金伯利质煌斑岩筒研究——一种新型的幔源碱性超基性岩

路迳岩筒属火山通道相,由金伯利质煌斑岩、角砾岩、角砾凝灰岩组成,富含幔源橄榄岩包体、普通辉石巨晶和岩球。造岩矿物是橄榄石、斜方辉石、单斜辉石、角闪石和金云母,深源特征指示矿物有镁铝榴石、铬透辉石、铬尖晶石和镁钛铁矿。岩石化学组成超低SiO2,低MgO,高Al2O3,富碱,富挥发组分。轻稀土元素富集,相容元素贫化,不相容元素明显富集。岩浆起源深度约85km。其中：岩体产状,富含包体、巨晶和岩球,岩石结构和构造,矿物组成,岩石化学组成超低SiO2、富碱、富挥发组分等特征与金伯利岩相似;但岩石化学组成高Al2O3,低MgO,K2O低于Na2O,REE和LREE/HREE偏低,部分微量元素的亏损或富集,金云母成分富TiO2,富TFeO,贫MgO,镁铝榴石、铬透辉石、铬尖晶石和镁钛铁矿的Cr2O3含量偏低,岩浆起源深度较浅,均与金伯利岩有重大差异,而更接近煌斑岩类。研究认为,是幔源岩浆岩的一种新类型,岩石名称界定为金伯利质煌斑岩。     

Cenozoic uplift of West Qinling, northeast margin of Tibetan plateau-a detrital apatite fission track record from the Tianshui basin

The Cenozoic sedimentation in the Tianshui basin, which is located at the junction of the liupanshan and West Qinling, northeast margin of the Tibetan plateau, provides a record for the regional tectonism and exhumation history of the surrounding mountains. Thermochronologic study on the detrital apatite grains from sandstones at Yaodian, near Tianshui, has revealed two rapid tectonic uplift-exhumation events of the source area, which happened at 23.7 and 14.1 Ma, respectively. The fast exhumation (0.34 mm/a) at 23.7 Ma, which recorded the tectonic uplift of West Qinling, led to the formation of the Neogene Tianshui basin and initiated the reception of alluvial deposits. This event is most likely in response to the synchronous tectonism of the Tibetan plateau. The source region experienced another rapid exhumation (1.05 mm/a) at 14.1 Ma, when the Tianshui basin began to depress broadly and fluvial-lacustrine sediments dominated the Late Miocene. Translated from Acta Sedimentologica Sinica, 2006, 24(6): 783–789 [译自: 沉积学报]     

近年国外传统村镇旅游研究进展及启示

近年来,随着传统村镇旅游的日益兴起,有关传统村镇的旅游学研究日益受到学术界重视和关注.总结了国内外关于传统村镇的旅游学研究进展,指出国外研究成果主要集中在传统村镇旅游发展影响研究、传统村镇旅游发展与文化原真性保持之间的关系、传统村镇旅游可持续发展等方面.国内研究与之相比,在研究内容、方法、领域、深度等方面仍有很大差距,有待进一步扩展和深入.今后应注意以下几方面问题:研究内容流于表层,应加强研究领域的延伸和深度的扩展;研究方法、手段较为单一,研究理论和方法焏待提高;理论研究滞后于旅游发展实践的现状焏待改善.     

上海市居民乡村旅游行为特征及感知研究

运用旅游心理学原理,采用比较分析和交互分析等研究方法,分析了上海市居民乡村旅游的人口学特征、行为偏好以及效果感知,并提出加强乡村旅游宣传力度、观念创新和服务管理等建议.     

Determination of vertical displacements over the coastal area of Korea due to the ocean tide loading using GPS observations

This paper describes the GPS applicability for detecting the vertical displacements of ground stations caused by ocean tide loading effects. An experiment was carried out using 12 permanent GPS stations located in the coastal area of Korea using data in the period 1 July until 26 August 2003. The relative height differences were calculated from hourly DGPS data processing based on the carrier-phase observation. The power spectra of the M₂ and N₂ constituents of ocean tide loading were derived using the CLEAN algorithm. The differential vertical displacements generated by the ocean tide loading effect are typically 3–25 mm in coastal area of the Korea. We compared the results from GPS with those of the ocean tide models, NAO.99Jb regional model and GOT00.2, FES99 global models. The M₂ (N₂) amplitude differences of vertical displacements between GPS and GOT00.2 is 1.22 ± 3.61 mm (1.01 ± 1.48 mm), and that of the M₂ (N₂) amplitude difference between GPS and FES99 is 0.04 ± 4.64 mm (0.64 ± 1.75 mm), whereas the M₂ (N₂) amplitude difference between GPS and NAO.99Jb are 0.05 ± 1.03 mm (0.86 ± 1.18 mm). The highest vertical displacements at the PALM station are found for 24.5 ± 0.7 mm from GPS observation, and 22.9 mm from the regional model NAO.99Jb and 13.17 and 10.00 mm from the global models GOT00.2 and FES99, respectively. These values show that the vertical displacements derived from GPS are in good agreement with those of the regional model NAO.99Jb around Korea, more than with the global models. This result indicated that GPS is an effective tool to measure the vertical displacement caused by the ocean tide loading effect in the coastal area, and we need to use the NAO.99Jb ocean tide model rather than the global ocean tide models in and around the Korean peninsula for position determination with permanent GPS installations. This work demonstrates that vertical displacement caused by the M₂ and N₂ constituents of ocean tide loading can be measured by carrier-phase DGPS.     

南方海相地震资料脊波非线性阈值去噪方法

小波分析方法在数据处理中已得到成功广泛的应用,这主要得益于它的局部时频分析能力,但是小波分析对方向的表征能力有限。脊波变换具备优越的方向选择性能,能更好地处理含有线状变化特征的信号。本文针对低信噪比地震记录,尝试研究利用脊波变换方法对其进行处理,提高剖面资料信噪比,突出同相轴信息。在对南方某油田的实际地震资料的处理中,可以发现处理后的地震剖面同相轴品质及连续性有了明显改善,信噪比增强,分辨率相应提高,体现出了该方法相对常规小波分析方法的优越性。     

The mean value concept in mono-linear regression of multi-variables and its application to trace studies in geosciences

The "mean value concept" in a mono-linear regression of multi-variables is clarified.Its applications to reconstruction of the past 90-year salinity of the sea surface water in Xisha Islands and to tracing the past 80 ka paleo-geomagnetic events from the Luochuan loess 10Be record are introduced in detail,which show the significance and the potential of the "mean value concept" in geoscience research.     

Robust H∞ control for aseismic structures with uncertainties in model parameters

This paper presents a robust H∞ output feedback control approach for structural systems with uncertainties in model parameters by using available acceleration measurements and proposes conditions for the existence of such a robust output feedback controller. The uncertainties of structural stiffness, damping and mass parameters are assumed to be norm-bounded. The proposed control approach is formulated within the framework of linear matrix inequalities, for which existing convex optimization techniques, such as the LMI toolbox in MATLAB, can be used effectively and conveniently. To illustrate the effectiveness of the proposed robust H∞ strategy, a six-story building was subjected both to the 1940 El Centro earthquake record and to a suddenly applied Kanai-Tajimi filtered white noise random excitation. The results show that the proposed robust H∞ controller provides satisfactory results with or without variation of the structural stiffness, damping and mass parameters.