富二价铁岩石信息提取及在铀矿勘查中的应用

本文利用航空高光谱CASI数据和岩石的光谱特征,提出一种快速提取富含Fe2+岩石信息的算法,并由此获取辉绿岩脉信息。经过实地验证,数据处理结果的精度较高,处理结果中辉绿岩脉规模及其走向等特征清晰。将提取的结果与铀矿异常信息对比分析,发现富含Fe2+的辉绿岩脉与铀异常具有很强的相关性。通过利用这种方法,在研究区南部又新发现了两条辉绿岩脉构造。     

计算机地形分析中的多边形迭加问题

在计算机地形分析中,研究地形多要素迭加分析的关键是解决多边形的迭加问题。本文通过对多边形迭加的数学方法的研究,提出了适合计算机多要素分析的原理和方法。     

复合混沌系统的矢量数据加密研究

根据矢量数据的特点和混沌映射系统的加密方法,本文提出了一种基于Logistic映射和Chebyshev映射的复合混沌系统。它通过使用迭代状态的周期替换,并输出整数化的混沌映射序列,有效地避免计算机有限精度产生的累计误差。该算法有较强的随机性、抗穷举攻击能力、抵御已知明文攻击能力和较好的时间代价。经过安全性分析,本算法可以较好地用于矢量数据的加密。     

Winkler model for dynamic response of composite caisson–piles foundations: Seismic response

A simplified method with a dynamic Winkler model to study the seismic response of composite caisson–piles foundations (CCPF¹) is developed. Firstly, with the dynamic Winkler model, the kinematic response of the CCPF subjected to vertically propagating seismic S-wave is analyzed by coupling the responses of caisson part and pile part. Secondly, a simplified model for the foundation–structure system is created with the structure simplified as a lumped mass connected to the foundation with an elastic column, and through the Fast Fourier Transformation (FFT) this model is enabled to solve transient seismic problems. Thirdly, the proposed method for the seismic response of CCPF-structure systems is verified by comparison against 3D dynamic finite element simulation, in which the Domain Reduction Method (DRM²) is utilized. Lastly, the mechanism and significance of adding piles in improving the earthquake resistance of the foundation and structure is analyzed through an example with different soil conditions. Discovered in this study is that adding piles under the caisson is an efficient way to increase seismic resistant capability of the soil–foundation–structure system, and the main mechanism of that is the elimination of the pseudo-resonance.     

论中国东部大型盆地区及邻区地质-地球物理复合尺度解析

作为对中国东部陆缘地带大型盆地区及邻区地质－地球物理综合研究的部分结果,本文的基本认识：（1）穿过松辽盆地的1孙吴－双辽断裂可能是东倾伯低角度壳内断裂;（2）松辽盆地和渤海湾盆地可能属于“混合型裂谷盆地”;（3）东海盆地台北坳陷处在多期次张性应力场环境中,使在其西部附近产生张性正断层系;（4）欧亚大陆东部新生代区域构造运动总体处于右旋走滑拉张环境,其动力因素包括板块运动和地幔物质运动;（5）研究区莫霍面具有较为复杂的变化;（6）复合尺度研究方法是地质－地球物理综合分析的必要手段。     

Synthesis and Characterization of Poly(2‐hydroxyethylmethacrylate‐hydroxyapatite) a Novel Composite for the Removal of Lead(II) from Aqueous Solutions

In the present study, a novel adsorbent, poly (2‐hydroxyethylmethacrylate‐hydroxyapatite) [P(HEMA‐Hap)], was prepared and characterized. The synthesis was achieved by means of free‐radical polymerization and a number of structural characterization methods, including FT‐IR, XRD, TGA, SEM, BET‐porosity, and swelling tests. Pb²⁺ adsorption was performed using a series of pH, time, and temperature ranges. The reusability of the composite was also tested. The results obtained indicated that the novel adsorbent is able to bind Pb²⁺ ions with strong chemical affinity. The adsorption results were fitted to the classic Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) sorption models. Thermodynamic parameters obtained demonstrated that the sorption process was spontaneous (ΔG < 0), endothermic (ΔH > 0), as expected. The process was also consistent with the pseudo‐second‐order model, and chemical adsorption was determined to be the rate‐controlling step. It was also shown that the composite could be used for five consecutive adsorption processes.     

堤坝隐患探测资料多维灰色综合评估方法

根据多维灰色系统综合评估理论,提出了一套堤防隐患的评估方法,并编制了相应的计算机软件.根据工程实际,确定了影响堤防安全的3个主要因素及相应的评价指标体系和权系数.用该方法对黄河下游某段堤防已探测到的隐患进行了综合评估.在203处堤防隐患中,有约15%的隐患危害程度比较严重,这一事实与实际相符.     

复合地层土压平衡盾构滚刀磨损规律及切削距离寿命预测分析

软硬不均复合地层中地质条件频繁变化,盾构滚刀磨损加剧严重制约施工效率。为探索复合地层土压平衡盾构机滚刀耐磨蚀改进措施,准确预测复合地层土压平衡盾构滚刀的磨损量与切削距离寿命,本文采用统计回归法对广州地铁18号线工程ZDK30+433.76~ZDK31+150.61区间盾构滚刀更换情况及磨损量进行统计分析。通过利用滚刀磨损量以及盾构掘进参数得到了适用于软硬不均复合地层的滚刀磨耗系数K。根据磨耗系数K及相应的滚刀磨损计算模型,对复合地层中土压平衡盾构滚刀磨损量及切削距离寿命进行预测分析,从滚刀的设计制作、施工参数、现场监管和渣土改良4个方面提出了复合地层滚刀的耐磨蚀改进措施,并对土压平衡盾构掘进参数进行优化,提出了沙湾水道段的推荐刀盘转速值。该研究成果为广州地铁18号线工程及类似地层条件下盾构滚刀磨损预测及换刀时机选取提供了工程经验与理论依据。