多道伽马能谱仪中的特征峰稳谱技术

介绍一种用于微机多道伽马能谱仪的稳谱装置及稳谱方法,该装置采用新型非易失性数字电位器、89C52控制器等大规模集成电路,具有集成度高、功耗低、可靠性高等优点.文中详细介绍了有关软硬件、稳谱方法及实际应用效果.试验结果表明,对102道微机伽马能谱仪在-5～5 ℃的工作环境下,其特征峰漂移≤±1道.     

新一代高灵敏度手提式X荧光仪的研制

介绍了新一代高灵敏度手提式X射线荧光仪 ,该仪器由电制冷Si PIN半导体X射线探测器、放射性同位素X射线激发源和基于PC/ 10 4工控机的 4 0 96道多道脉冲幅度分析器组成 ,对铜、锌、砷等元素的分析检出限为 10× 10 -6,适用于野外现场的天然岩石、土壤和水系沉积物的多元素含量的定量测定 ,基本满足新一轮地质大调查的需要 ,特别是二、三级异常点 (带 )的快速查证与野外追索工作。     

饱和黄土场地原位试验及液化势评价

目前,主要依靠室内动力试验对黄土液化势进行评价。由于黄土特殊的结构性,室内试验对其饱和的过程较为复杂,且与实际场地饱和黄土差异明显,导致室内黄土液化试验结果并不能代表现场饱和黄土的抗液化强度。本文选取兰州市西固区寺儿沟村某饱和黄土场地进行钻孔测试,现场实施了标准贯入试验、静力触探试验以及剪切波速测试。应用Robertson的土类指数分类图对该场地不同含水率黄土的土类进行了界定,确定了饱和黄土属于类砂土,有液化势。应用NCEER推荐方法,计算了3组原位试验数据的饱和黄土循环抗力比（CRR）,通过与1976年唐山地震和1999年集集地震液化土CRR对比,得出了饱和黄土抗液化强度很低的结论。     

基于天地图的便携式自然资源政务云平台研发

以国家天地图互联网数据为基础,以充分融合的某市地理信息三维倾斜数据、VR数据、专题数据与政务大数据为基础平台数据,在便携式移动设备上研发通用的政务大数据平台。并以云服务的形式提供大数据,为政府现场办公管理提供了科学的数据参考,在河长制管理、生态红线划分保护、工农业经济发展、旅游产业发展等方面进行了应用,在推动数字城市、智慧城市发展方面,具有积极的社会意义。     

手持GPS定位精度及其在物化探测网布设中的应用

对手持式GPS性能进行了系统测试,并介绍了坐标系转换过程中内置参数的求解方法,通过系统参数校正,能使其定位精度远远大于其标称（10～15 m）值,可以满足中大比例尺物化探测网布设的技术要求.     

便携式地质灾害应急调查工具箱的研究及应用

我国是突发性地质灾害频发的国家,提高地质调查队伍的应急调查效率成为当务之急。本文介绍了一种新研发的便携式地质灾害应急调查工具箱,具有在地质调查的团队合作性、应急性、野外性等多方面的突出特点。现场应用证明,便携式工具箱配合野外数据传输装置,能够快速采集、储存、传输现场资料。野外无纸化录入数据后,自动生成各种规范的地质调查表,实现采集、编辑、输出一体化,大幅度提高应急调查的综合效率,为突发性地质灾害应急调查提供了技术支撑。     

Support vector machines‐based modelling of seismic liquefaction potential

This paper investigates the potential of support vector machines (SVM)‐based classification approach to assess the liquefaction potential from actual standard penetration test (SPT) and cone penetration test (CPT) field data. SVMs are based on statistical learning theory and found to work well in comparison to neural networks in several other applications. Both CPT and SPT field data sets is used with SVMs for predicting the occurrence and non‐occurrence of liquefaction based on different input parameter combination. With SPT and CPT test data sets, highest accuracy of 96 and 97%, respectively, was achieved with SVMs. This suggests that SVMs can effectively be used to model the complex relationship between different soil parameter and the liquefaction potential. Several other combinations of input variable were used to assess the influence of different input parameters on liquefaction potential. Proposed approach suggest that neither normalized cone resistance value with CPT data nor the calculation of standardized SPT value is required with SPT data. Further, SVMs required few user‐defined parameters and provide better performance in comparison to neural network approach. Copyright © 2006 John Wiley & Sons, Ltd.     

手持式X射线荧光光谱仪测定富钴结壳样品中锰铁钴镍铜锌

便携式X射线荧光光谱仪可以快速进行多元素实时分析,在富钴结壳资源勘查中有广阔的应用前景,但是现有仪器的分辨率和稳定性有待进一步提高,特别是现场原位分析法的应用有待研究。本文针对富钴结壳中目标元素含量相对较高的特点,采用松散粉末法制样,建立了手持式X射线荧光光谱仪快速测定太平洋富钴结壳样品中Mn、Fe、Co、Ni、Cu和Zn的分析方法。该方法用多金属结核和富钴结壳国家标准物质进行验证,测定值的相对标准偏差(RSD)在0.2%~3.0%之间,测定值与标准值的相对误差为92.9%~107.6%。样品现场分析和实验室分析的数据对比表明,除了低含量Cu略有超差外,Mn、Fe、Co、Ni、Zn和品位均无超差,完全满足该类矿产资源勘查规程的要求。本法简单、高效,适用于对野外富钴结壳资源作出快速的初步评价。     

Prediction of ultimate axial load-carrying capacity of piles using a support vector machine based on CPT data

The support vector machine (SVM) is a relatively new artificial intelligence technique which is increasingly being applied to geotechnical problems and is yielding encouraging results. In this paper SVM models are developed for predicting the ultimate axial load-carrying capacity of piles based on cone penetration test (CPT) data. A data set of 108 samples is used to develop the SVM models. These data were obtained from the literature containing pile load tests and each sample contains information regarding pile geometry, full-scale static pile load tests and CPT results. Moreover, a sensitivity analysis is carried out to examine the relative significance of each input variable with respect to ultimate strength prediction. Finally, a statistical analysis is conducted to make comparisons between predictions obtained from the SVM models and three traditional CPT-based methods for determining pile capacity. The comparison confirms that the SVM models developed in this paper outperform the traditional methods.     

CPT-Based estimation of undrained shear strength of fine-grained soils in the Huanghe River Delta

The Huanghe River（Yellow River） Delta has a wide distribution of fine-grained soils. Fluvial alluviation, erosion,and wave loads affect the shoal area, resulting complex physical and mechanical properties to sensitive fine-grained soil located at the river-sea boundary. The cone penetration test（CPT） is a convenient and effective in situ testing method which can accurately identify various soil parameters. Studies on undrained shear strength only roughly determine the fine content（FC） without ma...