光学探生仪研制

光学探生仪主要用于在地震等灾害造成的残垣断壁中快速、准确地寻找被困人员。因此,在研制光学探生仪时,必须充分考虑灾害救助现场的恶劣工作条件和对仪器的特殊要求。本文首先简要介绍了光学探生仪研究的有关情况,然后对光学探生仪主要部件的设计、选型和实验进行了详细研究,探讨研制先进、实用的光学探生仪的途径。这对我国探生仪研制工作具有借鉴意义。     

The role of antecedent groundwater heads in controlling transient aquifer storage and flood peak attenuation in karst watersheds

Transient storage of floodwaters in aquifers is known to attenuate peak flows in rivers and drive subsurface dissolution. Transient aquifer storage could be enhanced in watersheds overlying karst aquifers where caves facilitate surface and groundwater exchange. Few studies, however, have examined controls on, or magnitudes of, transient aquifer storage or flood peak attenuation in karstic watersheds. Here we evaluate flood peak attenuation with multiple linear regression analyses of 10 years of river and groundwater data from the Suwannee River, which flows over the karstic upper Floridan aquifer in north-central Florida and experiences frequent flooding. Regressions show antecedent river stage exerts the dominant control on magnitudes of transient aquifer storage, with recharge and time to peak having secondary controls. Specifically, low antecedent stages result in larger magnitudes of transient aquifer storage and thus greater flood attenuation than conditions of elevated antecedent stage. These findings suggest subsurface weathering, including cave formation and enlargement, caused by transient aquifer storage could occur on a more frequent basis in aquifers where groundwater table elevation is lowered due to anthropogenic or climatic influences. Our work also shows that measures of groundwater table elevation prior to an event could be used to improve predictive flood models. © 2018 John Wiley & Sons, Ltd.     

NOAA WP-3D instrumentation and flight operations on AGASP-II

The second Arctic Gas and Aerosol Sampling Program (AGASP-II) was conducted across the non-Soviet Arctic in March and April 1986, to study the aerosol, gaseous, chemical, and optical properties of Arctic haze. One component of the program was supported with an instrumented NOAA WP-3D atmospheric research aircraft. Measurements of wind, temperature, ozone, water vapor, condensation nucleus concentration, and aerosol scattering extinction coefficient were used to determine the locations and properties of haze layers. The first three NOAA WP-3D research flights were conducted north of Barrow, Alaska, and over the Beaufort Sea northeast of Barter Island, Alaska. The next three sampled conditions in the high Arctic near Alert, Northwest Territories, Canada. All basic meteorological, gas, and aerosol systems are described. The WP-3D flight tracks and operations are presented.     

Determination of trace and rare-earth elements in Chinese soil and clay reference materials by ICP-MS

Inductively coupled plasma mass spectrometry(ICP-MS) has become a powerful tool for providing reliable analytical results in many laboratories around the word. In this study, the mixture of HF and HNO3 acids in high-temperature and high-pressure closed-vessel digestion technique were used to decompose some Chinese reference materials, and thirty seven elements were determined by ICP-MS. Most of the results for Chinese soil reference materials were found to be in reasonable agreement with the reference values, except Cs, Ta, Li, Ge, Zn, Nd, Tb and Ta whose values need to be revised. Their precisions were typically lower than 5% RSD. However, the Precisions of Chinese clay reference materials, especially for GBW03102 and GBW03102a, were significantly different with reference values, probably reflecting the existence of a coarser-grained fraction(70 μm) in samples, and the formation of fluorides in Al-rich samples during sample decomposition by using the mixture of HF and HNO3 acids. Moreover, thirty-seven trace elements covering the mass range from Li to U in four Chinese clay reference materials were firstly provided with good precision and accuracy in this study.     

云南中甸五村-移山晚三叠世沉积及盆地特征

五村-移山地区晚三叠世地层发育齐全，并在中咱地块边缘至甘孜-理塘结合带之间构成一个较为完整的沉积盆地。中甸、格咱和弥里淌三条平行控制性断裂将盆地由西向东依次横向分割成中咱微大陆五村台地边缘三角洲、哈工弧后断陷盆地、属都火山复理石盆地和尼汝弧前斜坡(盆地)。在上述4种构造-相区中沉积了各具特色的沉积物，具有不同基本层序结构、不同生物组合及沉积相特征。显示盆地经历下降-抬升-下降-抬升两个周期性演化过程。     

激光剥蚀电感耦合等离子体质谱分析石笋样品中多元素比值及45种元素含量

石笋样品的微量元素含量及Mg/Ca、Sr/Ca比值为高分辨的古气候重建提供重要指标。针对现有溶液分析技术易混合多个石笋微层、误差大的缺点,本文利用激光剥蚀电感耦合等离子体质谱技术(LA-ICP-MS)原位线扫描和点剥蚀方式对比分析了石笋生长轴方向的Mg/Ca和Sr/Ca空间分布趋势,研究表明二者均展现出显著的周期性变化特征,且周期性变化一致,其中40 μm束斑线扫描更具有稳定性强、分辨率高、快速简便的优点。通过探讨碳酸盐标准样品MASC-3与玻璃标准样品NIST 610、NIST 612、KL2G、ATHO-G的相对灵敏度系数关系和元素分馏行为,确定基体效应是造成相对灵敏度系数变化的主要原因。同时建立了以MASC-3、NIST 610和NIST 612多外标结合内标Ca归一定量分析石笋中45种元素方法,针对石笋碳酸盐样品,将主量元素Ca、Mg变形为碳酸盐形式,与其他元素加和归一,不仅改变了国内外研究中需要预先采用其他分析技术来测定内标元素含量的计算方法,而且有效地避免了C元素无法准确检测的问题,能够实现与Ca内标法校正结果的吻合。     

基于人工神经网络的区域地质灾害危险性预测评价

地质灾害危险性预测评价的准确性,主要取决于基础资料的可靠性和数学模型的合理性。论文结合工程实例,尝试用人工神经网络方法(改进的神经网络BP模型)对区域地质灾害危险性预测进行评价研究。然后与目前常用的方法(如层次分析法、信息量法和模糊综合评判法等)所得出的结果相比较。结果表明,运用人工神经网络方法对区域地质灾害危险性预测评价相对常用方法更准确、可靠,具有一定的实用意义及推广价值。     

祁连山北坡水热条件对林草分布的影响

采用气候学方法,计算了祁连山北坡不同海拔处的年降水量和乔木林年蒸散量,据此确定了满足乔木林需水的高度带。分析所得的7月均温10℃和6℃,可分别作为乔木林和灌木林生长的温度下限指标。据祁连山北坡水热条件的分布特点,确定了海拔2500—3200米处适宜发展乔木林,其生长以海拔2700—2900米处为最佳,海拔3200—3700米处适宜发展灌木林,其余山区只能生长草类。     

瞬变电磁场资料的联合时-频分析解释

本文充分利用瞬变电磁（TEM）信号包含的信息,采用联合时-频分析方法解释了TEM资料。文章选取了Wigner-Ville分布和Gabor展开的联合时-频分布（或表示）,将一维时间域信号拓展到时-频二维平面上,不仅将不同地电断面的响应成功地分开来,而且所显示的信号特征与地层电性结构之间有着明确的物理意义,从时间和频率两个方面同时描述了瞬变涡流场在地层中的激发和衰减的过程。利用时间窗数据和频率窗数据所进行的联合时-频反演,缩小了拟合差,提高了定量解释精度。     

地震动记录选取及其对网架屋盖动力响应的影响

地震动记录的合理选取对预测结构响应有着重要的作用。本文通过对风雨操场建筑混合结构的抗震性能分析,提出了一种对水平及竖向地震动频谱特性均进行控制的改进选波方法。为了评价不同选波方法的可靠性和有效性,根据初选条件选取55组三向地震动记录,并以55组地震动的统计反应谱作为目标反应谱,以55组记录计算的结构响应均值作为"预测值",通过与单周期点和双频段选波方法的计算结果对比,分析表明:改进选波方法计算的结构基底剪力、柱顶位移、支座位移和网架竖向位移的相对误差和变异系数均小于前两种选波方法,其计算结果更加可靠有效。