Phytoremediation of shallow organically enriched marine sediments using benthic microalgae

We examined whether replantation of benthic microalgae (BMA) can remediate shallow organically enriched sediment. Nitzschia sp., the dominant species in the tested area (Hiroshima Bay, Japan), was isolated and mass cultured, then replanted in the same area. Changes in the condition of the sediment were monitored for five months. During the study period, we observed an increase in redox potential (ORP) and a decrease in acid-volatile sulfide (AVS) in the experimental area, indicating that the sediment condition changed from reduced to oxic. Organic matter in the sediment, represented by chemical oxygen demand (COD), ignition loss (IL) and organic nitrogen (ON) decreased significantly, while inorganic nutrients (ammonia and phosphate) increased in the interstitial water. These changes imply that oxygen produced by the replanted BMA may have enhanced aerobic bacterial activity, accelerating the decomposition of organic matter. Thus, replantation of BMA shows potential as a novel and promising "phytoremediation" method for organically enriched sediment.     

利用地震噪声预报火山喷发

火山喷发之前岩浆压力会增大,导致火山筑积物的膨胀(Patanèet al,2003)。火山膨胀引起的地面形变可以通过各种技术手段来揭示,比如利用航天雷达干涉仪(Massonnetet al,2001)或应变与倾斜仪(Peltieret al,2005)。实时监测这种过程能为我们预报火山喷发提供有用的信息。然而,在某些情况下火山筑积物的膨胀可发生在地表上无法检测到任何效应的深度上,因而尽管付出了相当大的努力(Ratdomopurboand Poupinet,1995;Snieder and Hagerty,2004),但对于火山内部变化的监测还是证明是十分困难的。本文我们利用超过18个月间期记录到的地震噪声的性质说明,通过测量0.05%这种非常小的相对地震波速微扰可以连续监测到富尔奈斯火山的内部变化。火山喷发前几个星期地震波速的降低表明,火山筑积物在喷发之前的膨胀,可能是由于岩浆压力增大所致。这种火山筑积物膨胀的记录能力,应能提高我们预报火山喷发及其强度和潜在环境影响的能力。     

四维高分辨率活动构造研究

自野外调查的开创性论文发表以来,活动构造学已有100多年的历史,但它仍然是构造地质学中一个相对年轻的分支学科。该学科主要研究板块构造运动引起的应变积累和通过发生地震(或其他事件)对应变的释放。也就是说,活动构造旨在描述板块构造的过程。确定地震年代、断层滑动速率和其他常见的活动构造研究目标,极大地加深了我们对断层力学和地壳流变学等方面的理解。地震危险性评估和风险缓解方面的需求进一步推动了对大地震和潜在破坏性地震复发特征的研究。活动构造研究中的主要数据来源是地表和浅层地下断裂作用痕迹,两者分别通过地形地貌和地层资料显示。大约在40年前,地质学家开始通过对活动断层错断地层、地貌标志物的野外观察和航空照片解译,建立了地震复发的端元模型。自那以后,特别是在最近20年内,技术的发展极大地提高了地形数据的丰富性和分辨率,增强了对地层单元和地貌面进行定年的能力,这为我们建立更合理的地震复发概念模型奠定了基础。本文对近年来促进活动构造研究不断发展的高分辨率地形数据和测年方法进行了综述。     

主动空间试验中空间电荷波向电磁波的转换

本文理论分析了电子束沿地磁场穿越均匀、磁化等离子体密度跃变区域时,在弱磁场近似、哨声波激发、低频近似等几种典型情况下电子束流空间电荷波（Space charge wave）向电磁波的转换.先运用小信号假设求得电子束入射进均匀各向异性冷等离子体之后的色散关系和空间电荷波波数,然后借助于电磁波分量和电子束速度的边界条件,求解电子束在等离子浓度发生变化区域激发的波振幅,在几种典型情形下推导出空间电荷波转换为电磁波之间转换系数的近似解,给出了相应波辐射的坡印亭(Poynting)矢量表达式.结果表明,在渡越辐射（Transition radiation）情形下电子束可以在空间等离子体中激发出阿尔芬波（Alfven wave）和哨声波（Whistler wave）.所得结论可用于对主动空间试验结果的分析.     

Modeling of trophospheric ozone concentrations using genetically trained multi-level cellular neural networks

Tropospheric ozone concentrations, which are an important air pollutant, are modeled by the use of an artificial intelligence structure. Data obtained from air pollution measurement stations in the city of Istanbul are utilized in constituting the model. A supervised algorithm for the evaluation of ozone concentration using a genetically trained multi-level cellular neural network （ML-CNN） is introduced, developed, and applied to real data. A genetic algorithm is used in the optimization of CNN templates. The model results and the actual measurement results are compared and statistically evaluated. It is observed that seasonal changes in ozone concentrations are reflected effectively by the concentrations estimated by the multilevel-CNN model structure, with a correlation value of 0.57 ascertained between actual and model results. It is shown that the multilevel-CNN modeling technique is as satisfactory as other modeling techniques in associating the data in a complex medium in air pollution applications.     

黑色页岩建造中的金-铜

系统分析了岩性、岩相和古地理再造的概化结果以及不同金属矿化的显生宙高碳沉积建造的成因。文中还确定了金和铜矿化富集的决定性因素。     

用三分向台站的数字化资料确定震源深度

引言研究任何地震事件时,从地震宏观作用的研究到地震和核爆炸的识别,实际上都必须知道震源深度。确定震源深度是根据对记录初至震相的分析1956;1983),特别是对pP波和sP波初至相对于初动的时差分析来实现的。但是除了上述震相以外,在纵波开始部分可能存在其他一些转换波     

Nd and Sr Isotope Constraints on the Age and Origin of Proterozoic Meta mafic Volcanic Rocks in the Bainaimiao Wenduermiao District, South central Inner Mongolia, China

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Effect of Rock Structure on Statistical Characteristics of Acoustic Emission

A comparative study on acoustic emission during deformation of two kinds of granites with different structures under triaxial compression was performed using a new acoustic emission recording system with full-waveform record and broad-dynamic range. One is the Inada aplite-granite of homogeneous structure from Japan and the other is the Mayet granite with cemented natural joints from France. For the former granite, acoustic emission events are dispersed randomly and there is no clear clustering along the major fracture. For the latter granite, acoustic emission events are mainly concentrated near the joints. Acoustic emission events occur synchronously with the volumetric dilatation in the former one but far earlier than the volumetric dilatation in the latter one. The two kinds of granites are also clearly different in the frequency spectrum of acoustic emission. The former has a narrower frequency band and a higher frequency component, whereas the latter has a wider frequency band and generally a lowe