酸化过程对不同碳酸钙含量的海洋沉积物中总氮及其同位素分析的影响

为节约成本和样品,一些学者同时分析海洋沉积物中的碳、氮及其同位素（TOC、TN、δ¹³C和δ¹⁵N）。分析沉积物中的δ¹³C,需要对样品进行酸化去除无机碳,但是这一酸化过程会使TN和δ¹⁵N的分析结果产生偏差,且偏差范围与沉积物中无机碳含量（CaCO₃）有关。本研究选取了低CaCO₃含量（1-16%）和高CaCO₃含量（20-40%）的海洋沉积物样品,比较了酸化过程对TN和δ¹⁵N的影响。研究结果表明,酸化过程对海洋沉积物中TN和δ¹⁵N的分析结果产生了显著影响。对于低CaCO₃含量的样品,酸化导致样品中TN流失了约0-40%,δ¹⁵N偏移了约0-2‰;而对于高CaCO₃含量的样品,酸化导致样品中TN流失了约10-60%,δ¹⁵N偏移了约1-14‰。表明酸化对TN和δ¹⁵N的影响已经超过了仪器的误差范围0.002%（TN）和0.08‰（δ¹⁵N）,将影响TN和δ¹⁵N的环境指示意义。因此,即使海洋沉积物样品中CaCO₃含量很低,也必须用原样分析TN和δ¹⁵N以避免酸化过程的影响。     

M·V·罗蒙诺索夫金刚石矿床的某些特征(英文)

Ｍ·Ｖ·罗蒙诺索夫金刚石矿床位于阿尔罕格尔斯克金伯利岩省之内,地处东欧地台、波罗的海地盾和俄罗斯地台与文德—寒武纪活化的阿尔罕格尔构造带交接的部位。据Ｋ Ａｒ法定年,该矿床形成时代为（３５５±１０）Ｍａ,其它地质证据亦表明金伯利岩岩体形成时代介于上泥盆纪和中石炭纪之间。该矿床可划分出４个金伯利岩田,即Ｚｏｌｏｔｉｔｓｋｏｙｅ,Ｋｅｐｉｎｓｋｏｙｅ,Ｖｅｒｈｏｔｉｎ ｓｋｏｙｅ和Ｍｅｌｓｋｏｙｅ。按照深度,该床存在两类岩相,即火山角砾岩筒相和火山口相。两类岩相所产出的岩石类型有所不同,深度不同、蚀变类型也不同。金伯利岩矿物成分主要为金云母、铬尖晶石、铬透辉石、石榴子石和镁钛铁矿等。该矿床的金刚石晶体有不同形态,但以菱形十二面体最为常见,当粒度小于０５ｍｍ时,八面体形态金刚石增多,但无经济价值。在阿尔罕格尔岩省找到Ｍ·Ｖ·罗蒙诺索夫矿床是２０世纪的一大发现,它的金伯利岩成分稳定,内部构造相对简单并含有大量宝石级的金刚石。     

ENTRAINMENT FUNCTION OF SUSPENDED SEDIMENT IN OPEN CHANNELS

1　ＩＮＴＲＯＤＵＣＴＩＯＮ　Ｒｉｖｅｒｆｌｏｗｓｗｉｔｈｓｕｓｐｅｎｄｅｄｓｅｄｉｍｅｎｔｓａｒｅａｍｏｎｇｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｆａｃｔｏｒｓａｆｆｅｃｔｉｎｇｔｈｅｇｅｏｍｏｒｐｈｉｃｅｖｏｌｕｔｉｏｎ.Ａｋｅｙｆｅａｔｕｒｅｏｆｔｈｉ...     

南海颗粒有机碳通量的垂向变化及早期降解作用的标志物

南海不同水层的颗粒有机碳通量与表层沉积物有机碳积累率的对比 ,以及氨基酸、氨基糖、糖类物质的组成变化表明 ,南海水柱中的颗粒有机碳主要来源于近期生长的海洋浮游生物 ,仅有 1.4%～ 1.6 %初级生产力产生的有机碳进入深海水柱 ,而在深海盆地沉积物中积累的有机碳仅占初级生产力的 0 .2 2 %以下 .颗粒有机物通量与组成改变主要发生在表层数百米以及底层海水与沉积物界面之间 ,而在中下水层变化较小 . (TAA+TSUG)OC ,AA/AS ,Gluam/Galam ,Arom .AA/Non Prot.AA ,ASP/b ALA ,GLU/g ABA等指标在颗粒物沉积过程中逐渐减少 ,指示了有机物质的早期降解作用     

MyShake:全球智能手机地震台网的初步观测结果

MyShake是利用众包之力建立起来的一个全球智能手机地震台网。在MyShake应用程序发布后的最初6个月,下载量接近20万。平均每天大约有8 000部手机向MyShake档案库提供加速度波形数据。手机中的MyShake应用程序可以检测到P波并被P波触发,还能记录到震级为2.5及以上的地震事件。截止目前,MyShake已经记录到超过200个地震事件,包括发生在智利、阿根廷、墨西哥、摩洛哥、尼泊尔、新西兰、中国台湾、日本,以及横跨北美范围的地震。目前单次地震事件中记录到地震波形最多的是发生在美国加利福尼亚南部博里戈斯普林斯的M5.2地震,MyShake收集了该地震103条有用的三分量波形记录。随着Google Play商店上MyShake的不断下载,和公众对诸如地震序列发生期间的地震峰值产生兴趣,台网规模得到了迅速发展。关键点当今第一个利用个人智能手机提供加速度波形的全球地震台网;震级M2.5或更大时,手机上的地震检测算法被触发;20万部手机下载了MyShake应用程序,并为其提供了来自六大洲的地震波形数据。     

机器学习和向机器学习

机器学习实际上已经存在了几十年或者也可以认为存在了几个世纪。追溯到17世纪,贝叶斯、拉普拉斯关于最小二乘法的推导和马尔可夫链,这些构成了机器学习广泛使用的工具和基础。1950年(艾伦·图灵提议建立一个学习机器)到2000年初(有深度学习的实际应用以及最近的进展,比如2012年的AlexNet),机器学习有了很大的进展。在过去几年中,深度学习在各种应用领域获得巨大的成功,并且随着一些新的应用模式的出现继续开辟新的领域。最近,由于从大数据中提取有经济价值信息的需要、各种类型的神经网络和计算能力获得较大进展,以及易于使用的程序代码的出现,促使机器学习在石油和天然气工业中流行。在本文中,我们将展示机器学习如何帮助地球科学家在更短的时间内完成日常任务。演示地球科学家从机器中学习到的知识,如文档和图像分割、测井相识别、岩石物理测井预测和断层解释,并利用这些技术来检查他们的工作质量,获得细微的洞察力。另一个优点是,这些方法通过提供更精确的训练数据集来优化机器学习工作流程,从而推动模型的持续学习和提高。     

Petrogenesis of the Paleoproterozoic Guandishan Granitoids in Shanxi Province： Constraints from Geochemistry and Nd Isotopes

The Guandishan granitoids consist mainly of various granitoid intrusions with different scales, including the Huijiazhuang intrusion, Shizhuang intrusion and Hengjian intrusion, which were formed between 1906 Ma and 1848 Ma. On the basis of geological and petrological characteristics, these granitoids can be classified into two groups： the earlier gneissic granodiorites and monzogranites, and the later massive leuco-monzogranites. Their geochemical and Nd isotopic features indicate that they could be derived from complicated partial melting of supracrustal rocks with an affinity of continental arc materials, such as sandy shale and pelite, and with garnet, pyroxene, hornblende and plagioclase as residual phases. Biotite, feldspar and other minerals were most likely fractionated during the magma evolution. Their source may have an affinity with continental arcs, and the granitoids could be derived from the main syn-collisional to late-orogenic tectonic environment, which may be related to the final amalgamation between the Eastern and Western continental blocks in the North China Craton.     

Adaptive base-isolation of civil structures using variable amplification

Semi-active dampers are used in base-isolation to reduce the seismic response of civil engineering structures. In the present study, a new semi-active damping system using variable amplification will be investigated for adaptive baseisolation. It uses a novel variable amplification device （VAD） connected in series with a passive damper. The VAD is capable of producing multiple amplification factors, each corresponding to a different amplification state. Forces from the damper are amplified to the structure according to the current amplification state, which is selected via a semi-active control algorithm specifically tailored to the system＇s tmique damping characteristics. To demonstrate the effectiveness of the VAD-damper system for adaptive base-isolation, numerical simulations are conducted for three and seven-story base-isolated buildings subject to both far and near-field ground motions. The results indicate that the system can achieve significant reductions in response compared to the base-isolated buildings with no damper. The proposed system is also found to perform well compared to a typical semi-active damper.     

Gottfried Konecny:the ambassador of photogrammetry and remote sensing for 75 years

A 90th birthday would be a milestone celebration for any person,but exceptionally rare if the person is still active after 75 years of working and serving the photogrammetric and remote sensing communities worldwide.This unprecedented career is the motivation to reflect on the technological developments of the past 75 years in the light of Gottfried Konecny's lifetime achievements.I started to get to know Gottfried not long before he officially retired from the Institute for Photogrammetry and Engineering Surveys in 1998.Furthermore,I was not even born when he,as a young and talented scholar supported by the Fulbright Scholarship from the US Government,arrived at the Ohio State University(OSU),which has been my professional home for three decades.In the second half of Gottfried's 75-year career,the technological changes have been phenomenal,and,furthermore,shown an accelerating trend in the past few years.It is absolutely remarkable how Gottfried has been able to keep up with these rapid changes and advancing technologies and exploits them for mapping and,in general,for all the users of the geospatial field at large.Additionally,his open-minded and kind personality has been always a major plus to his technical skills and experiences,and ultimately helped him assist many colleagues to advance their careers,and along the way developed and increased the use of geospatial data and systems in support of many countries worldwide.