瞬态谱在地震与核爆识别中的应用

采用非稳态的ＷＤ理论,对５个哈萨克斯坦地下核爆及其邻近地区７个区域地震资料进行分析,研究了地下核爆和天然地震的瞬态谱特征、瞬时频率随时间的变化。结果表明,地下核爆的瞬态谱主要分布在高频：核爆的瞬态谱大多数集中于５-１０Ｈｚ;天然地震的瞬态谱散布在低频到高频的较大范围。核爆的瞬时频率在起始阶段（０＜ｔ＜０．７５ｓ）表现为线性,起始频率为负值;天然地震的瞬时频率以跳动形式迅速变化,起始频率正负交替。同时还对地震和核爆瞬态谱差异进行了初步解释。     

Tracing ground water input to base flow using sulfate (S, O) isotopes

Sulfate (S and O) isotopes used in conjunction with sulfate concentration provide a tracer for ground water contributions to base flow. They are particularly useful in areas where rock sources of contrasting S isotope character are juxtaposed, where water chemistry or H and O isotopes fail to distinguish water sources, and in arid areas where rain water contributions to base flow are minimal. Sonoita Creek basin in southern Arizona, where evaporite and igneous sources of sulfur are commonly juxtaposed, serves as an example. Base flow in Sonoita Creek is a mixture of three ground water sources: A, basin ground water with sulfate resembling that from Permian evaporite; B, ground water from the Patagonia Mountains; and C, ground water associated with Temporal Gulch. B and C contain sulfate like that of acid rock drainage in the region but differ in sulfate content. Source A contributes 50% to 70%, with the remainder equally divided between B and C during the base flow seasons. The proportion of B generally increases downstream. The proportion of A is greatest under drought conditions.     

A multivariate assessment of the coral ecosystem health of two embayments on the lee of the island of Hawai'i

Four coral-dominated coastal sites within two embayments (Kealakekua Bay and Honokōhau Bay) on the lee of the island of Hawai'i were studied to assess evidence of anthropogenic impacts in these relatively pristine locales. Nutrient-loading parameters were analyzed in relation to benthic composition data. Statistically, there were significant positive relationships between nitrate+nitrite, silicate, and ammonium with the abundance of macroalgae, coralline algae, and dead coral, and between delta(15)N and dead coral abundance. The north outside site of Kealakekua Bay and the south outside site of Honokōhau Bay appear to be most impacted by nutrient-loading factors in each bay, respectively. Comparisons with past nutrient data indicate that nutrient inputs have increased to the two bays, and that early impacts of these increased loadings are evident. It is predicted that at current nutrient-loading rates, the north sites of Kealakekua Bay and the south sites of Honokōhau Bay will exhibit evidence of further degradation in future years.     

Pyrolysis of spill oils adsorbed on zeolites with product oils recycling

Experimentally, a feasibility study for adsorption and catalytic pyrolysis of spill oils on Cu/ZSM-5 for recycling of light oils has been conducted in the present work. The adsorption and pyrolysis of model compounds such as heptane, toluene, and diesel (to stimulate the spill oils) on Cu/ZSM-5 have been investigated on a continuous fixed-bed reactor. By component fitted X-ray absorption near edge structural (XANES) spectroscopy, catalytic active species such as metallic copper (Cu) (77-84%) and Cu(2)O (6-7%) are found in the channels of ZSM-5 during pyrolysis of heptane or toluene. Pyrolysis of diesel effected by Cu/ZSM-5 yields gas (C(1)-C(5)) (32%) and light oil (68%) that can be used as auxiliary fuels.     

北京地震台gPhone重力仪同震响应特征分析

地震的同震响应包含了地震破裂及传播过程中的大部分信息,因此可用这些同震信息对地震震源的一些参数进行估计。2014年9~12月,马鲁古海发生5次M_S6.1~7.1强震,北京地震台的gPhone重力仪均有同震响应。本文从首波初至、地震频带响应、地震面波、同震变形幅度、同震持续时间等方面分析了重力仪的同震响应特征,并与STS-2宽频带地震计进行了波形对比分析。结果表明,相对于宽频带地震计,gPhone重力仪亦能提供丰富的由地震引起的地面运动信息,其首波初至、地震频带响应等与宽频带地震计有高度相似,且gPhone重力仪对长周期地震面波的响应很好,表现出其独有的特性。     

Uptake and distribution of N, P and heavy metals in three dominant salt marsh macrophytes from Yangtze River estuary, China

We examined the variation in aboveground biomass accumulation and tissue concentrations of nitrogen (N), phosphorus (P), copper (Cu), zinc (Zn) and lead (Pb) in Phragmites australis (common reed), Spartina alterniflora (salt cordgrass), and Scirpus mariqueter throughout the growing season (April-October 2005), in order to determine the differences in net element accumulation and distribution between the three salt marsh macrophytes in the Yangtze River estuary, China. The aboveground biomass was significantly greater in the plots of S. alterniflora than in the plots of P. australis and S. mariqueter throughout the growing season (P<0.05). In August, the peak aboveground biomass was 1246+/-89 gDW/m(2), 2759+/-250 gDW/m(2) and 548+/-54 gDW/m(2) for P. australis, S. alterniflora and S. mariqueter, respectively. The concentrations of nutrients and heavy metals in plant tissues showed similar seasonal patterns. There was a steady decline in element concentrations of the aboveground tissues from April to October. Relative element concentrations in aboveground tissues were at a peak during the spring sampling intervals with minimum levels during the fall. But the concentrations of total nitrogen and total phosphorus in the belowground tissues were relatively constant throughout growing season. Generally, trace metal concentrations in the aboveground tissues of S. mariqueter was the highest throughout the growing season, and the metal concentrations of S. alterniflora tissues (aboveground and belowground) were greater than those of P. australis. Furthermore, the aboveground pools of nutrients and metals were consistently greater for S. alterniflora than for P. australis and S. mariqueter, which suggested that the rapid replacement of native P. australis and S. mariqueter with invasive S. alterniflora would significantly improve the magnitude of nutrient cycling and bioavailability of trace metals in the salt marsh and maybe transport more toxic metals into the water column and the detrital food web in the estuary.     

基于Google Maps的“全球眼”视频监控系统的气象应用

“全球眼”(Global Eyes)视频监控系统是基于网络的数字化图形图像远程传输和处理系统,在很多领域都得到了应用,基于Google Maps设计,实现了“全球眼”气象视频监控系统,以B/S方式灵活地实现了“全球眼”气象视频监控.系统将视频监控技术与Google Maps结合起来,为气象服务提供了一套丰富直观的具体实况视频图像素材库,在气象网站、气象影视、多媒体气象电子显示屏等气象服务中得到很好的应用.“全球眼”视频监控系统在气象服务工作中的应用对防灾减灾工作有着重要的现实意义,为气象服务提供了实时的视频图像以及稳定、可信和有效的气象分析数据,也大大增强了防台防汛等气象服务能力.     

青藏高原东北缘地壳厚度与波速比研究

青藏高原是在印度板块和欧亚板块会聚作用下新生代时期形成的,是现今构造运动最强烈的地区之一.自印度-亚洲碰撞以来,高原内部及边缘发生了强烈的构造变形,在青藏高原周缘地区形成挤压转换造山带和侧向挤出地体群.     

汶川8.0级地震机理的探讨

2008年5月12日在汶川发生了8.0级大地震.中外学者采用多种方法和手段从地质、地球物理、地球化学等角度对汶川地震开展了多方面的研究,发表了大量研究论文.特别值得关注的是关于汶川地震的发震机理的研究论文数量非常多.     

Using recovery data to extend the effective duration of pumping tests

Collection of water-level recovery data is a common practice for pumping tests. The resulting data can provide some of the most useful information from the tests, but are rarely used to their full value. van der Kamp (1989) proposed a general method that uses recovery data to extend the effective duration of pumping. The method is straightforward to implement and applicable for simple or complex hydrogeologic settings. The only assumption invoked is that the response remains linear such that the principle of superposition can be applied. No other assumptions about the properties of the aquifer are required. The method can greatly increase the value of pumping tests by extending the effective duration of the tests for as long as significant residual drawdowns are observed.