Chronological Link Between the Abrupt Change of the Loess Grain Size Sequence and the Formation of River Terraces on the Eastern Margin of the Qinghai-Tibetan Plateau Since the Late Early-Pleistocene

Based on the study of magnetostratigraphy, magnetic susceptibility and grain size of Garz(e) A section on the southeastern margin of the Qinghai-Tibetan Plateau since the late early-Pleistocene, the basal age of Garz(e) loess is located at ～1.16 MaBP and a series of abrupt paleoclimatic changes is detected. The times of abrupt changes are of distinct series features, and the interval between each two adjacent abrupt changes is～50 kyr or ～100 kyr. The most significant abrupt changes occur at around 1.06, 0.85, 0.6, 0.46, 0.39 and 0.14 MaBP. There is a chronological link between the abrupt changes of paleoclimate and the formation of river terraces and it is almost simultaneous with a strengthening trend of neotectonic activities. Therefore, maybe the climatic transition contrail the timing of terrace formation, and the tectonic uplift originate potential energy and has a direct effect on channel incision,both the climatic transition and the tectonic uplift are important. Terraces are the products of the interaction of instable climatic variations and tectonic uplift. Like the loess-paleosol sequences, river terrace sequences are also controlled by the climate-tectonic coupling system and are ruled by climate-tectonic gyration with a ～100 kyr paracycle, which may be the short eccentricity period of the earth.     

气候变化对甘肃黄土高原土壤贮水量的影响

利用甘肃省黄土高原16个气象站1971~2000年气象资料、13个农业气象观测站及3个农业气象试验站土壤湿度资料,分析了近50年温度、降水及近30年土壤水分变化特征,用数理统计方法拟合了0~200 cm土壤贮水量动态变化,得出了土壤贮水量随气候变化的规律。研究表明,上世纪80年代以来,甘肃黄土高原土壤含水呈减少之势,0~200 cm土层土壤总贮水量春、秋季减少了40~90mm,夏季减少了20~36mm;土壤贮水适宜农作物生长的时段减少了2~3月,土壤水分匮缺的范围无论从时段及层次上都有所扩展。     

基于MapObjects的区域地质文献管理系统的建立

在进行区域地质研究的过程中,会涉及到大量的参考文献。当研究区域范围比较大、研究方法比较多的情况下,查找文献就会变成一项负担。本文以青藏高原的研究为例,利用VB开发了基于MapObjects的区域地质文献库管理系统。在对文献库进行综合管理的基础上,实现了由文献查找区域、在区域上查找文献等功能,很好地完成了地图与数据库的交互。     

滇黔桂“金三角区”岩浆活动与金矿成矿的关系

在分析研究区域岩浆活动的基础上，认为本区微细粒浸染型金矿的成矿作用与岩浆活动有着较为密切的关系：二者空间关系相互依存；基性侵入岩及火山岩是重要的赋矿岩石或矿化主岩；大量产于基性岩浆岩及火山岩区的金矿床（点）及外围金矿床（点），其成矿作用的矿源和水源都与岩浆活动有关．进一步的找矿应注意基性岩出露地区及其隐伏岩体上部的化探异常．     

贵州水城青山铅锌矿床的成矿地质特征

矿体主要赋存在上石炭统马平群和二叠系下统梁山组中，呈似层状、透镜状产出．主要成矿元素为Ｐｈ，Ｚｎ，Ａｇ，铅加锌品位大于２２．２７％．成矿受地层层位、岩性、纵向断裂、层间裂隙控制，辉绿岩与成矿关系密切．     

Apparent solubility of drugs in partially crystalline systems

Using several griseofulvin samples, representing different solid-state structures, the solubility behavior of drugs in both one-state (totally ordered, semiordered or disordered) and two-state systems was studied. Special attention was directed towards the surface structure of the particles. The partially crystalline samples were obtained by milling the raw material (crystalline standard) or storing the quenched sample (amorphous standard). The solid-state structure of the materials was studied using x-ray diffraction (XRD), differential scanning calorimetry (DSC), isothermal microcalorimetry (IMC), and scanning electron microscopy (SEM). The saturation concentration of the materials was studied in suspensions containing different dispersion concentrations of drug after centrifugation and filtration, using spectrophotometry. In all cases these dispersion concentrations exceeded the solubility of the drug. The solubilities were plotted vs. dispersion concentrations for each sample. Several solubility plateaus were found. The lowest and highest solubility plateaus corresponded to the solubilities of crystalline and amorphous standards. These plateaus were reached at 8 and 44 µg/mL for crystalline and amorphous griseofulvin standards, respectively. An intermediate plateau served as an indication of the existence of a totally semiordered structure. This was reached at 19 µg/mL for griseofulvin. Any deviation from these plateaus was suggested to be indicative of the existence of heterogeneity on the surface structure, which in most cases could be described as a two state system. In such cases, the apparent solubility was a function of dispersion concentration, until at very high dispersion concentrations (4000-20,000 µg/mL) the saturation concentration of the totally disordered (44 µg/mL) or semiordered (19 µg/mL) one-state phase was reached. No reduction in these values was observed during storage for 50 days. It is thus concluded that, in partially crystalline systems, the saturation concentration is an interfacial phenomenon, which depends on the amount, reactivity, and solid-state structure of the exposed solid surfaces in equilibrium with the solution. A simplified solubility model is proposed to qualitatively describe the relationship between established apparent solubilities (saturation concentrations) and different combinations of solid-state structures.     

黄土高原土壤侵蚀的人为影响程度研究综述

人类活动对黄土高原土壤侵蚀的影响程度始终是黄土高原土壤侵蚀和黄河泥沙变化研究中的热门问题。人类活动对黄土高原土壤侵蚀影响研究主要可以分为地质地貌学法,土地利用变化法,气候演变法和水土保持措施法等四类,地质地貌学方法又包括黄河下游冲积扇沉积模式、地貌循环理论、侵蚀的自然脉动、沟谷侵蚀速率、侵蚀期与堆积期轮回等方法。不同研究方法对人类活动的影响评价存在明显异同。通过对现有研究方法、结果和观点的整理与讨论,认为应该提取和组织高时空分辨率的自然与人类活动要素,恢复地史与历史时期侵蚀面貌,探讨人类活动与水土流失变化的过程与机制,评价和预测人类活动对土壤侵蚀的影响。     

共建渝鄂湘黔跨省民族地区金融服务体系

探讨金融服务体系支持民族地区经济发展的必要性，提出要发展民族经济，金融服务必须先行，建议渝鄂湘黔政府放开思路，着眼未来，心系大局，共建一个完善的为农村经济持续、健康、稳步发展服务的农村金融体系。     

黄土高原现状梯田和林草植被的减沙作用分析

2000年以来,黄河来沙明显减少。本文以黄土高原主要产沙区为对象,利用卫星遥感与实地调查相结合方法,获取2012年研究区各支流的梯田面积和质量信息,分析2010—2013年林草植被覆盖率及其较天然时期的变化;提出林草与梯田叠加作用地区的减沙量计算方法。基于流域尺度上构建的黄土丘陵沟壑区林草植被覆盖率与产沙系数、梯田比与减沙幅度之间的响应关系,计算在多年平均降雨条件下黄河龙门、北洛河状头、汾河河津、渭河咸阳和泾河张家山等5站以上现状林草植被和梯田的减沙能力,其值为10.65亿t,占该区天然年均来沙量的60%。     

黄土高原地区淤地坝产权制度改革与可持续发展

在沟道中建淤地坝作为黄土高原地区最主要的水土保持工程措施之一，长期以来受工程投资所限，工程建设缓慢，已建工程利用和管护脱节，年久失修的病险坝大量增加。