海相火山岩区地质填图方法——以北祁连山东段白银矿田古火山机构厘定为例

20世纪90年代以来,火山机构控矿理论在海相火山岩区块状硫化物矿床研究中得到了越来越多的关注,基于该理论的指导,在北祁连山东段的白银矿田取得了找矿突破性进展。其间,详细的海相火山岩相地质填图工作为白银矿田火山机构与成矿联系的研究及找矿突破奠定了坚实的基础。反映出在海相火山岩区推行合理可行的火山岩相地质填图方法至关重要。以白银矿田海相火山岩区为例,首先,对该区大比例尺火山岩相填图及古火山机构厘定成果进行介绍;其次,通过分析、借鉴此成功案例,总结海相火山岩区填图内容和技术方法;最后,阐述应用该方法在北祁连山中段祁连县一带海相火山岩区进行大比例尺填图的成功尝试。     

塔里木盆地西南地区早中寒武世岩相古地理

塔里木盆地西南地区早中寒武世岩相古地理存在一定争议,这制约了该区的勘探评价。综合利用露头、钻井和地震资料,开展沉积相、地震相分析,并结合区域构造背景,恢复了岩相古地理格局,提出了相应的沉积模式。中下寒武统发育陆棚相、开阔台地相、局限台地相、蒸发台地相和缓坡相。震旦纪末期麦盖提斜坡南部形成水下低隆起,向南在西南坳陷区残留部分被动陆缘,主要发育缓坡相、陆棚相;麦盖提斜坡区地势较高,地层较薄,主要发育局限台地和蒸发台地潮坪;巴楚隆起区水体局限,在干燥炎热气候下形成了厚度较大的蒸发台地膏盐湖沉积。巴楚隆起区和麦盖提斜坡区中下寒武统膏盐岩分布广泛,与下伏碳酸盐岩可构成良好的储盖组合,西南坳陷区残留部分被动陆缘,烃源岩发育条件较好,这表明塔西南具有较好的油气前景。     

Dissolution sequestration mechanism of CO<Subscript>2</Subscript> at the Shiqianfeng saline aquifer in the Ordos Basin,northwestern China

This study focused on the target injection layers of deep saline aquifers in the Shiqianfeng Fm. in the Carbon Capture and Sequestration (CCS) Demonstration Projects in the Ordos Basin, northwestern China. The study employed a combination method of experiments and numerical simulation to investigate the dissolution mechanism and impact factors of CO₂ in these saline aquifers. The results showed (1) CO₂ solubility in different types of water chemistry were shown in ascending order: MgCl₂-type water < CaCl₂-type water < Na₂SO₄-type water < NaCl-type water < Na₂CO₃-type water < distilled water. These results were consistent with the calculated results undertaken by TOUGHREACT with about 5% margin of error. CO₂ solubility of Shiqianfeng Fm. saline was 1.05 mol/L; (2) compared with distilled water, the more complex the water’s chemical composition, the greater the increase in HCO₃ ^?concentration. While the water’s composition was relatively simple, the tested water’s HCO₃ ^?concentrations were in close accord with the calculated value undertaken by the TOUGHREACT code, and the more complex the water’s composition, the poorer the agreement was, probably due to the complex and unstable HCO₃ ^? complicating matters when in an aqueous solution system including both tested HCO₃ ^?concentration and calculated HCO₃ ^?concentration; (3) the CO₂ solubility in the saline at the temperature conditions of 55 °C and 70 °C were 1.17 and 1.02 mol/L. When compared with the calculated value of 1.20 and 1.05 mol/L, they were almost the same with only 1 and 3% margin of error; concentrations of HCO₃ ^? were 402.73 mg/L (0.007 mol/L) and 385.65 mg/L (0.006 mol/L), while the simulation results were 132.16 mg/L (0.002 mol/L) and 128.52 mg/L (0.002 mol/L). From the contrast between the tested data and the calculated data undertaken by the TOUGHREACT code, it was shown that TOUGHRACT code could better simulate the interaction between saline and CO₂ in the dissolution sequestration capacity. Therefore, TOUGHREACT code could be used for the inter-process prediction of CO₂ long-term geological storage of CO₂; (4) The Ca²⁺ concentration and SO₄ ^2?concentration in saline water had less effect on the solubility of CO₂ and HCO₃ ^?concentration. In addition, TDS and pH values of saline affected not only the solubility of CO₂, but also the conversion of CO₂ to HCO₃ ^? due to that they can affect the activity and acid-base balance. So in fact, we just need to consider that the TDS and pH values are main impact factors in the dissolution sequestration capacity of CO₂ geological sequestration in deep saline aquifers.     

Ecological function regionalization of cultural heritage sites in Turpan,China, based on GIS

The protection for historical and cultural heritage and their surrounding environments is much more important than any other preventive efforts made by humans, so how to protect them and achieve sustainable utilization should be a priority. Regionalization is an efficient and a sustainable tool to manage the protected areas. In this study, based on regionalization of natural protected areas theory, we used ecological sensitivity analysis to regionalize the heritage sites in Turpan, China. Factors for the analysis are topography, ecological environments, human activity, and landscape resources. Based on the analysis of environmental status and spatial variation of ecological sensitivity in Turpan, this paper aims at developing a regionalization scheme and provides a scientific basis for protection and restoration of vulnerable historical and cultural sites. Our study results showed that 75% of the heritage sites in Turpan have sensitivity which is under dangerous condition and requires better planning and protection. This study provided a reliable and scientific way to regionalize heritage sites in the study area and which also can be transferred to other locations with similar situation.     

情境建模下的LBS智能信息服务推送方法

为满足移动互联网用户的个性化信息服务需求,引入用户兴趣模型匹配技术,提出了一种基于情境建模下的LBS智能信息推送服务模式,通过构建位置过滤模块、用户兴趣模型匹配及智能信息分类模块,实现了对推送信息的层层过滤,并同时结合反馈处理部分的修正功能实时改进推送模型的精度,从而提高了信息服务的质量和效率,使推荐的信息资源更加符合用户的实际需要。原型系统的实际应用表明了该方法的有效性。     

含云卫星影像配准算法研究

影像上云层的存在不仅覆盖了大量地面有效信息,也给正射影像生产流程中的空三平差等环节造成不利影响。因此,含云卫星影像通常不具备较高的定位精度,在生产应用中被大量闲置。而这些影像的晴空区域仍含有较多的信息,带来了资源的浪费。本文针对国产高分辨率卫星影像,提出了一种顾及云层影像的影像自动配准算法。首先采用Otsu分割与形态学运算相结合的云检测方法以实现卫星影像的云区自动提取;然后在云检测结果的辅助下,将云层中匹配点剔除,优先保证晴空区域的定位精度。本文研究有助于充分挖掘含云影像中的有用信息,提升国产高分辨率卫星影像的应用价值。     

沙漠地区地震勘探随机噪声建模及其在噪声压制中的应用

随机噪声是影响地震勘探有效信号的主要因素,其存在大大降低了地震记录的信噪比.在噪声压制方法不断被改进的同时,对随机噪声特性进行研究,了解噪声的产生机制是对其进行压制的先决条件,目前对噪声的研究主要是特性研究以寻找规律性,对其进行定性定量的分析还比较少.本文根据塔里木沙漠地区实际采集环境,考虑到噪声的连续性给计算带来的不便,假设各类噪声源以点源的形式分布在检波器周围,依据相应理论确定各类噪声源的源函数,其激发的噪声经由波动方程传播,将随机噪声作为各类噪声源共同作用的综合波场,建立随机噪声的理论模型.通过分析不同种噪声对地震记录的影响,选取合适的滤波方法对其进行压制,实验结果表明,通过建立沙漠地区随机噪声的理论模型,为选择有效的滤波方法,提高地震记录信噪比起到理论指导作用.     

GNMF小波谱分离在地震勘探噪声压制中的应用

地震勘探资料噪声压制及信噪比提高是整个地震勘探信号处理过程中的重要任务,随着地震勘探深度的增加及其复杂性,人们对地震数据质量的要求越来越高.勘探环境的复杂化使得采集到的地震资料中有效信号被大量噪声淹没,无法清晰辨识,严重影响后续的数据处理与解释.小波去噪是地震勘探中常用且发展较成熟的一种方法,但是其涉及到的阈值函数选取问题一直令人困扰,虽然已有多种阈值函数被提出,但仍存在各自的缺陷.本文利用小波分解在时域及频域良好的信号细节体现特性,引入模式识别中的非负矩阵分解(NMF)谱分离思想,针对小波系数阈值优化问题,提出了一种小波域图非负矩阵分解(GNMF)消噪算法.该方法首先在小波分解基础上,利用GNMF算法实现小波分解系数谱中信号分量与噪声分量的谱分离,然后通过反变换重构各分离子谱对应的子信号,最后利用K均值聚类算法将得到的多个子信号划分为信号类及噪声类,最终得到重构信号及分离噪声.合成记录和实际地震资料的消噪结果验证了新方法在提高信号与噪声分离准确性和精度方面的有效性,同时新方法避免了阈值选取造成的噪声压制不理想或有效成分损失问题.与小波消噪结果的对比及数值分析也说明了新方法在噪声压制及有效成分保持方面的优势.     

基于NPP数据和样区对比法的青藏高原自然保护区保护成效分析

在青藏高原选择11个代表性自然保护区,基于高寒草地植被净初级生产力（Net Primary Production,简写NPP）变化过程数据,比较分析了自然保护区与其相邻等面积区域的NPP变化差异;采用样区对比法,在自然保护区内外选取21组对比样区,比较自然保护区建立前后及其内外的生态状况,评估了自然保护区的保护成效。研究表明：1. 1982-2009年间,82%的代表性自然保护区NPP比保护区周邻区域及青藏高原的平均水平低,反映了自然保护区的生态系统状况更为脆弱;2. 在代表性自然保护区中,曼则塘自然保护区的NPP增长趋势最为明显,塔什库尔干野生动物自然保护区的NPP增长趋势最弱;除色林错自然保护区外,以草甸和湿地为主的自然保护区NPP增速明显高于以草原与荒漠草地为主的自然保护区;3. 代表性样区的研究发现：① 自然保护区内76%以上的样区和国家级保护区内82%以上的样区NPP增加幅度明显高于保护区外对应样区的增幅;② 取得明显保护效果的有中昆仑、长沙贡玛、若尔盖和色林错等自然保护区;曼则塘自然保护区的东南部边缘地区和塔什库尔干野生动物自然保护区的北部边缘地区的效果不明显,可能与保护区及其周邻地区人类扰动增强密切相关;③ 高寒草甸类型自然保护区的保护效果最为显著,高寒草原类型自然保护区的保护效果较差。本研究展示了样区对比法在评估大区域生态变化中所具有的独特优势,其关键在于科学设计样区并进行合理的空间抽样。