福建省东北部沿海罗源湾互花米草盐沼环境下粘性沉积物的侵蚀-沉降过程

根据在福建罗源湾互花米草盐沼内的沉积动力要素(水深、流速、悬沙浓度和沉降速率)的观测及表层沉积物的粒度分析结果,罗源湾互花米草盐沼表层沉积物组份以粉砂和粘土为主,为粘性沉积物;互花米草盐沼内的潮流流速很小,最大值不超过7cm/s,相应地,底部切应力也相对较小,悬沙在潮周期内多处于沉降状态,表层沉积物在涨潮初期和落潮后期多发生侵蚀.在台风显著影响下,潮流流速平均值变化很小,但水流紊动能量和底部切应力显著增大,导致表层沉积物多处于侵蚀状态,在台风登陆期间潮周期内净侵蚀通量可达到40.099kg/m2;台风影响过后,底部切应力逐渐减小,沉积物逐渐不发生侵蚀,悬沙多发生沉降,整个潮周期内以悬沙沉降为主.     

东秦岭钼矿带成岩成矿背景及时空统一性

东秦岭钼成矿带呈近东西向沿华北大陆南缘地球化学边界展布,矿化表现为等间距北东向成串产出。在洛南－栾川地区深部是一个轴向近东西向且向西倾伏的幔向斜,其走向控制了华北块体南缘地球化学边界。沿北北东向的重力梯度带方向上,刚性的结晶基底发生隐性的构造破裂组合或不均匀调整作用。它们与古大祟边缘相平行的深断裂束互相叠加,形成状分布的深断裂组合,控制了壳幔同熔型花岗岩浆的侵位、形成一系列中酸性小岩性。含矿岩石类型主要有花岗斑岩、石英二长岩,构成了巨量的钼、钨、锌、铜、金矿化集中区。成矿地质背景和同位素年龄表明,控岩控矿构造与岩浆活动发生在燕山期,具有时空统一性。     

面向多重空间冲突解决的移位场模型

制图综合中的移位在解决空间冲突时,需要顾及多种上下文条件下的邻近目标的空间冲突,同时要保持目标群分布模式形态。本研究针对该问题,建立了多力源作用下的移位场模型,实现满足以上条件的多边形目标群的移位。该模型在Voronoi图剖分结构中,通过邻近距离阈值探测空间冲突,并作为斥力发生源,基于多源斥力的向量和计算得到最终移位的方向与偏移距离。该模型同时利用群组的方式保持空间目标的分布模式形态。本研究通过街区中建筑物群的综合试验,验证了基于该移位场模型的移位不会产生新的空间冲突,较好地保持了移位前的相对空间关系。     

Mechanism for calcite dissolution and its contribution to development of reservoir porosity and permeability in the Kela 2 gas field,Tarim Basin,China

This study is undertaken to understand how calcite precipitation and dissolution contributes to depth-related changes in porosity and permeability of gas-bearing sandstone reservoirs in the Kela 2 gas field of the Tarim Basin, Northwestern China. Sandstone samples and pore water samples are col-lected from well KL201 in the Tarim Basin. Vertical profiles of porosity, permeability, pore water chem-istry, and the relative volume abundance of calcite/dolomite are constructed from 3600 to 4000 m below the ground surface within major oil and gas reservoir rocks. Porosity and permeability values are in-versely correlated with the calcite abundance, indicating that calcite dissolution and precipitation may be controlling porosity and permeability of the reservoir rocks. Pore water chemistry exhibits a sys-tematic variation from the Na2SO4 type at the shallow depth (3600-3630 m), to the NaHCO3 type at the intermediate depth (3630―3695 m),and to the CaCl2 type at the greater depth (3728―3938 m). The geochemical factors that control the calcite solubility include pH, temperature, pressure, Ca2 concen-tration, the total inorganic carbon concentration (ΣCO2), and the type of pore water. Thermodynamic phase equilibrium and mass conservation laws are applied to calculate the calcite saturation state as a function of a few key parameters. The model calculation illustrates that the calcite solubility is strongly dependent on the chemical composition of pore water, mainly the concentration difference between the total dissolved inorganic carbon and dissolved calcium concentration (i.e., [ΣCO2] -[Ca2 ]). In the Na2SO4 water at the shallow depth, this index is close to 0, pore water is near the calcite solubility. Calcite does not dissolve or precipitate in significant quantities. In the NaHCO3 water at the intermedi-ate depth, this index is greater than 0, and pore water is supersaturated with respect to calcite. Massive calcite precipitation was observed at this depth interval and this intensive cementation is responsible for decreased porosity and permeability. In the CaCl2 water at the greater depth, pore water is un-der-saturated with respect to calcite, resulting in dissolution of calcite cements, as consistent with microscopic dissolution features of the samples from this depth interval. Calcite dissolution results in formation of high secondary porosity and permeability, and is responsible for the superior quality of the reservoir rocks at this depth interval. These results illustrate the importance of pore water chemis-try in controlling carbonate precipitation/dissolution, which in turn controls porosity and permeability of oil and gas reservoir rocks in major sedimentary basins.     

基于Ts-NDVI特征空间的绿洲土壤水分监测算法改进

土壤水分胁迫是干旱区绿洲生态环境和可持续发展面临的主要问题,开展区域尺度下大面积、高精度的土壤水分监测,有利于该地区旱情预报、作物估产、气象水文等领域研究。以T_s-NDVI特征空间为理论基础,以新疆渭干河-库车河三角洲绿洲为研究靶区,选择典型干湿季节下Landsat 8遥感影像,在传统温度-植被干旱指数（TVDI）算法基础上,考虑大尺度研究区下垫面异质性（植被覆被、地形起伏）对辐射能量平衡的影响,分别采用植被水分指数（VWIs）、加入大气温度（T_a）和DEM校正后的地表温度（T_s）与NDVI相结合,构建了植被干旱指数（VDI）和改进型温度-植被干旱指数（iTVDI）,并结合同期实测土壤水分数据对3种算法进行比较。结果表明：3种算法在一定程度上均能比较客观反映旱情特征,与表层土壤含水量呈现不同程度的负相关,其中,iTVDI相关性最好,TVDI次之,VDI相关性最低;相较植被生长初期而言,3种算法均在植被生长成熟期具有更好的水分监测能力。     

老挝甘蒙省钾镁盐矿床含矿段的矿物学和地球化学特征及成因

老挝甘蒙省钾镁盐矿床位于呵叻盆地的东隅,本文以该矿床ZK318钻孔的含矿段———下盐层为研究对象,对其开展了系统的矿物学和地球化学特征研究。结果表明,矿石矿物以石盐、钾石盐和光卤石为主,含少量方硼石和硬石膏。根据矿物与主量元素的分布特征,将下盐层分为5个次层,由下至上顺序为:盐岩层(石盐为主)→钾盐岩层(钾石盐为主)→光卤石岩层(光卤石为主)→薄盐岩层(石盐为主)→钾盐岩层(钾石盐为主)。微量元素Br值均大于200×10-6,表明卤水来源于海水;由盐岩层→钾盐岩层→光卤石岩层,B含量呈现出逐渐升高的趋势,表明B含量与卤水盐度呈线性关系。但顶部钾盐岩层的B含量高达890×10-6,与少量方硼石的存在相吻合,指示成矿卤水除了海水外,还有深部热液的贡献。按照卤化物卤水蒸发浓缩的顺序,光卤石是该卤水浓缩的最后阶段,但在光卤石沉积之后,又晶出一薄层石盐,表明曾经历过一次短暂的淡水补给。上、下两层钾石盐具有基本相同的Br含量,分别为1 790×10-6和1 792×10-6,且均直接沉积在石盐之上,故为原生钾石盐,而非光卤石的次生淋滤产物。认为甘蒙省钾镁盐矿床为海源陆相沉积,海水和深部热液是成钾物质的主要来源,钻孔中出露的两层钾石盐均为原生沉积。     

The research of the time variation of H2O maser

To explain the intensity fluctuations observed from bursts of W3(OH) and Cep A H₂O masers in the period of 50–60 days, we propose a new idea that energy of the maser pump is injected in the maser region with pulse form not only once but several times, and that it is supplied by the radiation diffusing through the gas cloud, in spite of the pump mechanism being radiation pump or collision pump. With our model the fits are obviously better than what many authors obtained in previous literature.     

华南李家沱剖面寒武纪纽芬兰世海水氧化还原性质演化及其驱动因素

大气-海洋含氧量的演化对埃迪卡拉纪-寒武纪转折期的后生动物大爆发事件具有重要影响.为探讨寒武纪纽芬兰世中国南方海洋氧化还原性质的演化及其初级生产力、海水硫酸盐浓度等演化驱动因素, 分析了李家沱剖面纽芬兰世留茶坡组和小烟溪组微量元素、有机碳含量、有机碳同位素、总硫含量、黄铁矿硫同位素等.该剖面沉积于斜坡-盆地环境且出露齐全.该剖面上V/Sc、Th/U及Mo、U、V、Ni、Cu等元素的富集系数呈现出5个变化旋回, 其中留茶坡组中上部和小烟溪组中部各存在一氧化环境段, 其余层段处于缺氧环境, 而Re/Mo则显示仅在小烟溪组中部水体出现过短暂的氧化环境和含有游离H₂S的硫化环境, 其余层段处于没有游离H₂S的缺氧非硫化环境.Ba、Ni、Cu、Zn、Cd等微量元素的富集系数及TOC表明: 留茶坡组的有机质沉降量和埋藏量都明显小于上覆小烟溪组; 而在小烟溪组中, 其中部有机质的沉降量和埋藏量最低, 下部最高, 上部次之.TOC/TS、TS以及黄铁矿硫同位素的垂向演化趋势等都显示李家沱剖面纽芬兰世大都处于低海水硫酸盐浓度环境.低海水硫酸盐浓度是造成李家沱剖面纽芬兰世缺氧水体未富集游离H₂S的主要原因.大气含氧量的升高是导致李家沱剖面小烟溪组中部出现短暂氧化环境以及近硫化环境的主要原因.      

地理国情数据集成管理研究与实现

简要阐述了湖南省地理国情数据的内容与特点;针对数据集成管理、统计分析和应用服务的需要,从设计思想、系统架构、系统功能等方面对地理国情数据库管理与应用服务系统进行了分析和设计;结合湖南省工作实践,构建了省级地理国情空间数据库,开发了地理国情数据库管理与应用服务系统,可为类似数据集成管理平台建设提供参考和借鉴.     

辽西地区侵入岩与内生金属成矿

通过对辽西地区侵入岩的分布、形成时代和地质特征、侵入岩成因、岩石组合及与内生金属矿产的关系的分析 ,总结出成矿作用和成矿规律 ,提出找矿方向