琼东南盆地深水区松南-宝岛凹陷反转构造带发育特征及油气地质意义

利用新三维地震资料对松南-宝岛凹陷反转构造带发育特征、形成期次进行研究,并从构造背景及力学机制两个方面探讨反转构造的成因机制。研究结果表明,松南-宝岛凹陷反转构造带主要发育一系列"上凸下凹"的大型褶皱背斜,伴生NWW向弱走滑断裂构造和NNW向张剪构造。反转构造及其伴生构造符合NEE右旋剪切应力场特征,形成时间与东沙运动一致,表明该反转构造带可能受晚中新世南海东北部东沙运动产生的右旋走滑应力场作用控制。反转构造有利于研究区圈闭的重建和改造,对琼东南盆地东部新区油气运移和重新优选分配的认识,具有重要的油气地质意义。     

8.0级地震大形势预测反思

2008年5月12日汶川(31.0°N,103.4°E)8.0级大地震,造成了数十万人员伤亡,震惊世界.对这次8级特大地震,没有做出短临预报,深感愧疚!对这次8级特大地震监测预报工作进行科学总结和反思,震前有否觉察?作者信箱:符干,fugan6618@tom.com     

持久、迁移性有机污染物的水污染现状、分析检测方法和去除技术

持久、迁移性有机污染物(PMOC)具有高极性、化学性质稳定的特点,故难被土壤以及沉积物吸附。该类化学物质的环境释放可导致其在地下水以及饮用水中富集。目前,由于缺乏有效的分析技术手段,水体中大量未知的PMOC仍待进一步分析和识别。本次研究将从定义、特性和判别标准等方面系统介绍该类污染物,同时,对欧洲国家的PMOC管控现状和政策法规进行总结和归纳。此外,以全氟烷基酸为例,对比、讨论了我国和欧洲地表水和地下水中PMOC的污染现状,并针对不同种类的PMOC详细介绍了相关的分析方法和水处理技术。最后,对PMOC的未来研究趋势进行前瞻,以期为我国化学品风险管理以及饮用水资源保护提供参考依据。     

北京山区泥石流预警阈值初步研究

泥石流预警阈值,是突发地质灾害防灾减灾的重要参考指标。本文结合北京山区泥石流灾害特点和已有降雨阈值研究成果,一方面在泥石流沟易发性、物源和危害人数进行分级的基础上,提出不同级别沟谷在不同前期降雨条件下,不同发灾概率的激发雨量,极大地方便了中短期预警实际工作;另一方面将泥石流流域降雨量、土壤含水率、次声、泥位4个参数,作为泥石流短临灾害预警关键物理参数,开展了泥石流专业监测设备预警阈值研究。最终,从技术层面上构建不同时间维度的泥石流监测预警阈值体系,为北京山区泥石流监测预警提供技术支持。     

1982年12月2日耀斑随时间变化的半经验模型

我们利用南京大学太阳塔中的多波段光谱仪,在H_α、H_β和CaⅡ H、K三个波段同时拍到了1982年12月2日日面S15W11处的一个SB级耀斑的光谱。本文给出其中七个时刻的谱线轮廓及有关参数的序列。在非局部热动平衡条件下计算了耀斑随时间变化的半经验模型,结果显示了色球耀斑的演化过程。利用模型得到了一些色球物质蒸发参数,结果同根据SMM的X射线观测所作的估计相一致。     

Potential impacts of invasive Spartina alterniflora on spring bird communities at Chongming Dongtan,a Chinese wetland of international importance

Invasive smooth cordgrass (Spartina alterniflora, hereafter Spartina) has been expanding rapidly in the estuarine wetlands at Chongming Dongtan (East China) at the expense of native sea-bulrush (Scirpus mariqueter, hereafter Scirpus) and common reed (Phragmites australis, hereafter Phragmites). To examine the potential impacts of the Spartina invasion on bird diversity, we compared the abundance and species richness of birds in habitats created by Spartina, Phragmites, Spartina mixed with Phragmites, Scirpus, and the bare intertidal zone at Chongming Dongtan in spring 2008. Most birds were recorded in the native habitats, with songbirds and breeding birds being most abundant in the Phragmites habitats, and waterbirds and migrants being most abundant in the Scirpus habitats and bare intertidal zone. Both species number and population densities of birds were lower in the exotic Spartina habitats than in the other four habitats. Although some songbirds and breeding birds used the Spartina-invaded habitats, and even preferred Spartina-invaded habitats to Scirpus habitats and bare intertidal zone, their densities were lower in the Spartina-invaded habitats than in the native Phragmites habitats. This might have resulted from the dense Spartina stands restricting bird movement and providing insufficient useable food for most birds. We conclude that the spread of exotic Spartina has negative impacts on local bird communities. Because Chongming Dongtan is an important stopover site for energy replenishment of shorebirds in the East Asian–Australasian Flyway, urgent measures are needed to control further spread of Spartina and to restore the native habitats for birds.     

On Integrated Hard X-Ray Broken-Up Spectra of Solar Flares

The summation of two single power-law spectra with a rather big difference of the spectral indices and with comparable intensities looks like a broken-up spectrum. The spatially integrated hard X-rays contain contributions from different sources, like footpoint and looptop sources. Within the standard scenario of solar flares, the power-law index difference between the footpoints and looptop should be two. Taking the M7.6 flare on 24 October 2003 as an example, we showed that the hard X-ray spectrum itself for footpoints and looptop is a single power-law, but the spatially integrated spectrum presents a broken-up form. It is also shown that the time-integrated spectrum could present a broken-up form, although the spectrum in further refined intervals presents a single power-law. It is concluded that the integrated broken-up spectrum observed here is produced either by the summation of individual sources or by the temporal variation of a single source, not by the acceleration itself.     

南海北部上层海洋变化的定点观测分析

对南海季风试验(CSMEX)加密观测期(IOP)“实验3”号船在南海北部获得的CTD温盐和声学多普勒流速剖面仪(ADCP)海流等观测资料进行分析,给出东沙群岛西南部大陆坡附近IOP两个阶段定点观测的海洋分量部分结果,通过分析海水的动力、热力学结构,描述夏季风暴发、维持期间该测站上层海洋的变化,讨论近表面水的温度、盐度和海流对海面风场的响应.     

天然状态与饱和状态下的不稳定斜坡危险性对比分析

本文依据北京市房山区史家营乡大村涧村的调查成果,借助于有限元分析软件,建立居住区附近影响范围内的边坡三维工程地质力学模型和弹塑性模型,利用有限差分法分析,对单一矸石堆边坡和矸石-岩土混合型边坡,进行计算分析,对比分析了这两种边坡在天然状态下与饱和状态下的安全系数,最终进行了边坡危险性评价。     

Spatial and temporal trend of sewage pollution indicated by coprostanol in Macao Estuary,southern China

Bottom sediments and a ²¹⁰Pb dated sedimentary core in Macao Estuary were quantitatively analyzed with GC-MS for coprostanol and other sterols. Higher coprostanol concentrations were detected at Port Interior and Lower Qianshan River, indicative of serious sewage pollution from densely populated Macao Island and Zhuhai City. However, very low concentrations of coprostanol were detected around Coloane Island as well as Port Exterior and Maliuzhou River except sites adjacent sewage outlets. Coprostanol pollution in Macao Estuary originates mainly from locally direct discharge of untreated wastewater. The concentrations of coprostanol in ZJ-9 were mainly in range of 150–280 ng/g with an average of 210 ng/g for more than 20 years from early 1970s to early 1990s. However, it increased obviously since 1993, and reached the highest in 1995–1996. However, a sharp decrease of coprostanol concentration from 470 to 31 ng/g after 1996 was observed corresponding to the first wastewater treatment plant in Taipa Island going into action.