On Geodynamic Evolution of Simao Region (Southwestern Yunnan, China) during Late Paleozoic and Triassic

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＳｉｍａｏｒｅｇｉｏｎ (ＳＷＹｕｎｎａｎ ,Ｃｈｉｎａ) ,ｓｉｔｕａｔｅｄｂｅ ｔｗｅｅｎｔｈｅＡｉｌａｏｓｈａｎｂｅｌｔｉｎｔｈｅｅａｓｔａｎｄｔｈｅＬａｎｃａｎｇｊｉａｎｇｚｏｎｅｉｎｔｈｅｗｅｓｔ (Ｆｉｇ .1) ,ｉｓａｋｅｙａｒｅａｔｏｃｈｒｏｎｏｌｏｇｉｃａｌｌｙｃｏｎｓｔｒａｉｎｌａｔｅＰａｌｅｏｚｏｉｃｃｏｍｐｒｅｓｓｉｏｎａｌｄｅｆｏｒｍａｔｉｏｎｓａｎｄｔｈｕｓｏｆｐｒｉｍｅｉｎ ｔｅｒｅｓｔｗｈｅｎｄｉｓｃｕｓｓｉｎｇｔｈｅｐｌａｔｅ ｔｅｃｔｏｎｉｃｈｉ…     

加拿大地盾麻粒岩区的含金铁建造：一个太古代的深部金成矿体系

在加拿大地盾的苏必利尔省东部，金产于混合岩化副片麻岩区的变质铁建造之中。位于距英云闪长岩入体１００ｍ的主要金矿点，经受了类矽卡岩的变质作用，该变质作用出现于麻粒岩级变质作用的晚期。尽管矿化作用产于高级变质围岩之中，但它具有许多低级太古宙绿岩带金矿化作用的特征，例如：（１）富Ａｕ、Ａｓ、Ｓ、Ｓｂ、Ｗ、Ｕ和ＦｅＯ；（２）贱金属／金比值低；（３）金在毒砂中作为包体存在；（４）位于长英质侵入体附近；（５）富铁的碎裂围岩；（６）相近的成矿时间（大约２６５０Ｍａ）。这种金矿化出现于变质作用的峰期附近，并代表了晚太古代广泛发育的地壳深部成矿作用体系。本文的主要结论是太古代金矿化作用的主要特征与深部地壳地质作用有关，而不是与上部地层如绿岩带的淋滤作用有关。     

Seismic analysis of diagrid structural frames with shear-link fuse devices

This paper presents a new concept for enhancing the seismic ductility and damping capacity of diagrid structural frames by using shear-link fuse devices and its seismic performance is assessed through nonlinear static and dynamic analysis.The architectural elegancy of the diagrid structure attributed to its triangular leaning member configuration and high structural redundancy make this system a desirable choice for tall building design.However,forming a stable energy dissipation mechanism in diagrid framing remains to be investigated to expand its use in regions with high seismicity.To address this issue,a diagrid framing design is proposed here which provides a competitive design option in highly seismic regions through its increased ductility and improved energy dissipation capacity provided by replaceable shear links interconnecting the diagonal members at their ends.The structural characteristics and seismic behavior(capacity,stiffness,energy dissipation,ductility) of the diagrid structural frame are demonstrated with a 21-story building diagrid frame subjected to nonlinear static and dynamic analysis.The findings from the nonlinear time history analysis verify that satisfactory seismic performance can be achieved by the proposed diagrid frame subjected to design basis earthquakes in California.In particular,one appealing feature of the proposed diagrid building is its reduced residual displacement after strong earthquakes.     

西藏措勤地区中生代的构造变形

：１∶１０万野外地质填图发现,在措勤地区北侧的白垩系中发育了一系列逆冲推覆构造和褶皱构造,且有侵入岩体分布,又被未变形的火山凝灰岩不整合覆盖。根据侵入岩的钾长石和角闪石及其不整合的火山凝灰岩中蚀变斜长石的ＡｒＡｒ法同位素年龄、沉积物质的组成和沉积地层的空间展布等特征,笔者推测这些逆冲断层和褶皱构造均发育于晚白垩世,并早于第三纪。     

金属矿床的地球化学分类

在地壳的地球化学场中,金属矿床是极为密集的异常,它常具比较明显的同心环带状结构和递减的边界。我们所观察到的异常规模是极不相同的,但在大多数情况下它们不超过10~8—10~9M~3,这说明其局限性或密集性。解决说明这种异常强度的问题比较复杂。与元素分配(这种分配可由元素的平均含量及分散度估计)比较均匀的岩石体及其建造不同,金属矿床是由矿体和金属晕组成,在一般情况下,它的特点是有规律增长的富集度,并且具有显     

CRETACEOUS AND TERTIARY BOUNDARY IN THE TINGRI REGION OF SOUTHERN TIBET

CRETACEOUS AND TERTIARY BOUNDARY IN THE TINGRI REGION OF SOUTHERN TIBETtheNNSFProject(49872 0 0 3)andtheNationalProject (G19980 40 80 0 )ofChina     

在第四纪研究委员会第一届学术会议上的讲话

在中国第四纪委具会成立以前, 在刊物上未见透露这一喜讯, 故苏联第四纪委员会事先不知道, 因之他们不能在大会上致以祝贺。     

Comparison of polycyclic aromatic hydrocarbon distributions and sedimentary organic matter characteristics in contaminated, coastal sediments from Pensacola Bay, Florida

In this study, we examined the distribution of polycyclic aromatic hydrocarbons (PAHs) in a contaminated coastal area and the characteristics of the natural organic matter in tandem. We present a detailed study of PAH concentration, distribution, and organic matter characteristics of three core samples from Pensacola Bay, Florida. Solid-state 13C Nuclear Magnetic Resonance (NMR), pyrolysis gas chromatography coupled with mass spectrometry (GC-MS), and tetramethyl ammonium hydroxide (TMAH) thermochemolysis GC-MS were applied to obtain structural details about the sedimentary organic matter. Elemental compositions (carbon and nitrogen) and estimates of black carbon contents are also reported. These coastal sediments were found to contain more PAHs in the upper 15 cm layers than in the bottom 15-25 cm samples. The samples that contained the most PAHs also contained the least amount of aromatic carbon and contained a significant amount of paraffinic carbon. Lignin-derived pyrolysis and TMAH thermochemolysis products were abundant and generally higher in all of the samples in comparison to those reported for modern coastal sediments, indicating a large flux of terrestrial carbon. The black carbon contents were found to range from 4.3% to 6.8%, which are significantly lower than other reports of black carbon in sediments, which represent as much as 65% of the total organic carbon content. The low black carbon content suggests that this type of refractory carbon may not be as responsible for regulating PAH distribution as indicated by other researchers.     

东北黑土区保护性耕作的发展现状与成效研究

东北黑土区承担着国家粮食安全“稳压器”的重要责任。然而,由于长期超负荷开发利用导致黑土日益退化,黑土资源的永续利用受到严重制约。理论与实践证明,保护性耕作是保护黑土地、推动黑土耕地质量和耕作效益绿色增长的发展模式。综述了保护性耕作的基本内涵及其在东北黑土区的发展现状与技术概况,从保护性耕作在土壤保持、保墒效益、结构改善、固碳培肥和土壤生物多样性增加、节本增效等方面系统评估了东北黑土区实施保护性耕作后的生态与经济效益,提出黑土区实施保护性耕作存在的问题与未来发展方向,以促进黑土地保护与利用协调发展、推动保护性耕作高质量跨越式发展。     

全球城市研究热点与进展——首届“全球城市与城市区域”青年学者学术研讨会会议综述

首届"全球城市与城市区域"青年学者学术研讨会暨华东师范大学城市与区域科学学院学术论坛于2018年11月16-17日在上海华东师范大学中山北路校区成功举办,来自英国、中国香港和上海等科研院所的城市地理学界的30多位学者,其中不乏国家自然科学基金优秀青年科学基金项目入选者、中组部"青年千人计划"入选者等,参加了本次会议。会议经过热烈而富有成效的讨论后一致认为,全体城市研究热点为全球城市空间更新、全球城市区域发展、全球城市创建政策和全球城市区域网络等。与会学者还讨论了中国全球城市与区域研究发展方向。