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S-wave crustal and upper mantle's velocity structure in the eastern Tibetan Plateau——Deep environment of lower crustal flow

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science China Earth sciences 2008年第2期51卷 263-274页

作者： Paul SILVER carnegie institution of Washington Washington DC 20015 USA

A teleseismic profile consisting of 26 stations was deployed along 30°N latitude in the eastern Tibetan Plateau. By use of the inversion of P-wave receiver function, the S-wave velocity structures at depth from surface to 80 km beneath the profile have been determined. The inversion results reveal that there is significant lateral variation of the crustal structure between the tectonic blocks on the profile. From Linzhi north of the eastern Himalayan Syntaxis, the crust is gradually thickened in NE direction; the crustal thickness reaches to the maximum value (~72 km) at the Bangong-Nujiang suture, and then decreased to 65 km in the Qiangtang block, to 57―64 km in the Bayan Har block, and to 40―45 km in the Sichuan Basin. The eastern segment of the teleseismic profile (to the east of Batang) coincides geographically with the Zhubalong-Zizhong deep seismic sounding profile carried out in 2000, and the S-wave velocity structure determined from receiver functions is consistent with the P-wave velocity structure obtained by deep seismic sounding in respect of the depths of Moho and major crustal interfaces. In the Qiangtang and the Bayan Har blocks, the lower velocity layer is widespread in the lower crust (at depth of 30―60 km) along the profile, while there is a normal velocity distribution in lower crust in the Sichuan Basin. On an average, the crustal velocity ratio (Poisson ratio) in tectonic blocks on the profile is 1.73 (σ = 0.247) in the Lhasa block, 1.78 (σ = 0.269) in the Banggong-Nujiang suture, 1.80 (σ = 0.275) in the Qiangtang block, 1.86 (σ = 0.294) in the Bayan Har blocks, and 1.77 (σ = 0.265) in the Yangtze block, respectively. The Qiangtang and the Bayan Har blocks are characterized by lower S-wave velocity anomaly in lower crust, complicated Moho transition, and higher crustal Poisson ratio, indicating that there is a hot and weak medium in lower crust. These are considered as the deep environment of lower crustal flow in the eastern Tibetan Plateau. F

关键词： eastern Tibetan Plateau crustal and upper mantle’s structure teleseismic receiver function lower crustal flow

Seismic anisotropy of upper mantle in eastern Tibetan Plateau and related crust-mantle coupling pattern

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science China Earth sciences 2007年第8期50卷 1150-1160页

作者： Paul SILVER Lucy FLESCH carnegie institution of Washington Washington DC 200015 USA

By using the polarization analysis of teleseismic SKS waveform data recorded at 116 seismic stations which respectively involved in China National Digital Seismograph Network, and Yunnan, Sichuan, Gansu and Qinghai regional digital networks, and portable broadband seismic networks deployed in Sichuan, Yunnan and Tibet, we obtained the SKS fast-wave direction and the delay time between fast and slow waves of each station by use of the stacking analysis method, and finally acquired the fine image of upper mantle anisotropy in the eastern Tibetan Plateau and its adjacent regions. We analyzed the crust-mantle coupling deformation on the basis of combining the GPS observation results and the upper mantle anisotropy distribution in the study area. The Yunnan region out of the plateau has dif-ferent features of crust-mantle deformation from the inside plateau. There exists a lateral transitional zone of crust-mantle coupling in the eastern edge of the Tibetan Plateau, which is located in the region between 26° and 27°N in the west of Sichuan and Yunnan. To the south of transitional zone, the fast-wave direction is gradually turned from S60°―70°E in southwestern Yunnan to near EW in south-eastern Yunnan. To the north of transitional zone in northwestern Yunnan and the south of western Sichuan, the fast-wave direction is nearly NS. From crust to upper mantle, the geophysical parameters (e.g. the crustal thickness, the Bouguer gravity anomaly, and tectonic stress direction) show the feature of lateral variation in the transitional zone, although the fault trend on the ground surface is inconsis-tent with the fast-wave direction. This transitional zone is close by the eastern Himalayan syntaxis, and it may play an important role in the plate boundary dynamics.

关键词： upper mantle anisotropy SKS wave fast-wave direction crust-mantle coupling lithospheric deformation

A Novel Two Domain-Fusion Protein in Cyanobacteria with Similarity to the CAB/ELIP/HLIP Superfamily： Evolutionary Implications and Regulation

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Molecular Plant 2008年第1期1卷 155-166页

作者： Oliver Kilian Anne Soisig Steunou Arthur R. Grossman Devaki Bhaya Department of Plant Biology The Carnegie Institution Stanford CA 94305 USA

Vascular plants contain abundant, light-harvesting complexes in the thylakoid membrane that are non-covalently associated with chlorophylls and carotenoids. These light-harvesting chlorophyll a/b binding （LHC） proteins are members of an extended CAB/ELIP/HLIP superfamily of distantly related polypeptides, which have between one and four transmembrane helices （TMH）. This superfamUy includes the single TMH, high-light-inducible proteins （Hlips）, found in cyanobacteria that are induced by various stress conditions, including high light, and are considered ancestral to the LHC proteins. The roles of, and evolutionary relationships between, these superfamily members are of particular interest, since they function in both light harvesting and photoprotection and may have evolved through tandem gene duplication and fusion events. We have investigated the Hlips （hli gene family） in the thermophilic unicellular cyanobacterium Synechococcus OS-B＇. The five hli genes present on the genome of Synechococcus OS-B＂ are relatively similar, but transcript analyses indicate that there are different patterns of transcript accumulation when the cells are exposed to various growth conditions, suggesting that different Hlips may have specific functions. Hlip5 has an additional TMH at the N-terminus as a result of a novel fusion event. This additional TMH is very similar to a conserved hypothetical, single membrane-spanning polypeptide present in most cyanobacteria. The evolutionary significance of these results is discussed.

关键词： fusion proteins Cyanobacteria N-Terminus stress conditions Large Hadron Collider Growth conditions photostability Regulation (biology) Thylakoid Membrane Tracheobionta gene duplication Analogy superfamily Chlorophyll Evolutionary

Oxygen as a catalyst in the Earth's interior?

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National science Review 2021年第4期8卷 7-8页

作者： Yanhao Lin Wim van Westrenen Center for High Pressure science and Technology Advanced Research Earth and Planets Laboratory Carnegie Institution for Science Department of Earth sciences Faculty of Science Vrije Universiteit Amsterdam

The abundance of the element oxygen is not only crucial for life at the surface of the Earth, but also greatly affects the properties and dynamics of the interior of our planet. The combination of a highly oxidized at...

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When water meets iron at Earth's core-mantle boundary

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National science Review 2017年第6期4卷 870-878页

作者： Ho-Kwang Mao Qingyang Hu Liuxiang Yang Jin Liu Duck Young Kim Yue Meng Li Zhang Vitali B.Prakapenka Wenge Yang Wendy L.Mao Center for High Pressure science and Technology Advanced Research Geophysical Laboratory Carnegie Institution Department of Geological sciences Stanford University High Pressure Collaborative Access Team(HPCAT) Geophysical Laboratory Carnegie Institution Center for Advanced Radiation Sources University of Chicago

Hydrous minerals in subducted crust can transport large amounts of water into Earth’s deep mantle. Our laboratory experiments revealed the surprising pressure-induced chemistry that, when water meets iron at the core-mantle boundary, they react to form an interlayer with an extremely oxygen-rich form of iron, iron dioxide, together with iron hydride. Hydrogen in the layer will escape upon further heating and rise to the crust, sustaining the water cycle. With water supplied by the subducting slabs meeting the nearly inexhaustible iron source in the core, an oxygen-rich layer would cumulate and thicken, leading to major global consequences in our planet. The seismic signature of the D″ layer may echo the chemical complexity of this layer. Over the course of geological time, the enormous oxygen reservoir accumulating between the mantle and core may have eventually reached a critical eruption point. Very large-scale oxygen eruptions could possibly cause major activities in the mantle convection and leave evidence such as the rifting of supercontinents and the Great Oxidation Event.

关键词： high pressure core-mantle boundary water and iron

Deep Volatiles as the Key for Energy and Environments of the Four-Dimensional Earth System

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Engineering 2019年第3期5卷 393-394页

作者： Ho-Kwang Mao Craig M. Schiffries Center for High Pressure science and Technology Advanced Research (HPSTAR) Shanghai 201203 China Geophysical Laboratory Carnegie Institution for Science Washington DC 20015 USA

Carbon, hydrogen, oxygen, nitrogen, sulfur, and their compounds are volatile components that dominate the thin and fragile atmosphere, hydrosphere, and biosphere on Earth’s habitable surface. However, the vast majority of these volatiles are hidden in the deep interior, where the high pressure–temperature conditions drastically and categorically alter the physics and chemistry of the volatiles. Like the bloodstream of an organism, the circulations and interactions of volatiles in the deep Earth modulate climate, resources, energy, natural hazards, and other factors that define the Earth as a unique living and changing planet.

关键词： Four-Dimensional Earth System Deep Volatiles

Optical system research of multi-object fiber spectroscopic survey telescope

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Research in Astronomy and Astrophysics 2021年第6期21卷 199-206页

作者： Hua Bai Ding-Qiang Su Ming Liang Stephen A.Shectman Xiang-Yan Yuan Xiang-Qun Cui National Astronomical observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China School of Astronomy and Space science&Key Laboratory of the Ministry of Education Nanjing UniversityNanjing 210023China observatories of the carnegie institution for science 813 Santa Barbara StreetPasadenaCA 91101USA

In the first part of this paper,four different Cassegrain optical systems with their correctors are designed and studied for multi-object fiber slit spectroscopic *** aperture in 6.5 m and field of view 3°are taken for these optical *** observation wavelength range is 0.365-0.95μm,the maximum zenith distance for observing is 60°,the maximum diameter of these lenses is 1.66 m,the altitude of the telescope site is 2500 m,two correctors are composed of 4-piece lenses and the other two are 5-piece *** results obtained are:f-ratio about 3.7,the image quality for all four systems with EE80D≤0.60″,the linear diameter of the focal surface is about 1.2 m and 11 000 fibers can be set on *** the limit of size of fused silica and optical glass,the maximum diameter for lens is about 1.7 *** a 6.5 m telescope is about the largest one if using the above *** the multiobject spectroscopic survey is greatly important,we also studied some telescope optical systems having their aperture near or larger than 10 m used for the multi-object fiber spectroscopic *** ideas are introduced in the last section of this paper.

关键词： telescopes techniques:miscellaneous techniques:spectroscopic methods:miscellaneous surveys instrumentation:miscellaneous

High-Pressure Experimental Studies on Geo-Liquids Using Synchrotron Radiation at the Advanced Photon Source

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Journal of Earth science 2014年第6期25卷 939-958页

作者： Yanbin Wang Guoyin Shen Center for Advanced Radiation Sources The University of Chicago HPCAT Geophysical Laboratory Carnegie Institution of Washington

We review recent progress in studying silicate, carbonate, and metallic liquids of geological and geophysical importance at high pressure and temperature, using the large-volume high-pressure devices at the third-generation synchrotron facility of the Advanced Photon Source, Argonne National Laboratory. These integrated high-pressure facilities now offer a unique combination of experimental techniques that allow researchers to investigate structure, density, elasticity, viscosity, and interfacial tension of geo-liquids under high pressure, in a coordinated and systematic fashion. Experimental techniques are described, along with scientific highlights. Future developments are also discussed.

关键词： high pressure synchrotron melts liquid structure magma dynamics mantle dynamics

How to detect melting in laser heating diamond anvil cell

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Chinese Physics B 2016年第7期25卷 31-35页

作者：杨留响 Center for High Pressure science and Technology Advanced Research Shanghai 201203China High Pressure Synergetic Consortium Geophysical LaboratoryCarnegie Institution of WashingtonArgonneIL 60439USA

Research on the melting phenomenon is the most challenging work in the high pressure/temperature field. Until now,large discrepancies still exist in the melting curve of iron, the most interesting and extensively studied element in geoscience research. Here we present a summary about techniques detecting melting in the laser heating diamond anvil cell.

关键词： high pressure laser melting diamond anvil cell