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New moon from an old hand

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Chinese Science Bulletin 2004年第17期49卷 1788-1800页

作者： Michael John O’Hara Institute of Geography and Earth Sciences University of WalesAber- ystwyth SY23 3DBWalesUK

The outcome of the Apollo lunar exploration program 1969—1974 was a model of lunar petrogenesis which ignored the probability of selective volatilisation of gases and alkalis from fire-fountaining lunar basalts. It overlooked the fact that the average compositions of the erupted basalts were those of plagioclase-saturated and low-pressure cotectic liquids on eruption, clearly indicating that they were not primary magmas. The basalts may have undergone evolution by gabbro fractionation within the lu- nar crust, perhaps in large lava lakes now solidified as the lunar maria. The existing model involving a global magma ocean and plagioclase flotation to form the lunar crust arises solely from the incorrect assumption that the basalts are primary magmas. The plagioclase flotation hypothesis re- quires the presence of a significant positive europium anom- aly in the lunar highland crust, and was founded upon its alleged presence. However, that positive anomaly is neither established by the original data set nor by the much broader current data set. Critical observations, and experiments which will advance the debate are suggested, and alternative interpretations outlined.

关键词：阿波罗飞行月球标本挥发性斜长岩饱和度铕可选择解释

Land use in semi-free ranging Tonkean macaques Macaca tonkeana depends on environmental conditions： A geographical information system approach

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Current Zoology 2011年第1期57卷 8-17页

作者： Cedric SUEUR Paul SALZE Christiane WEBER Odile PETIT department of Ecology and Evolutionary Biology Princeton University 08544 Princeton USA Ethologie des Primates departement d'Ecologie Physiologie et Ethologie UMR 7178 CNRS-UdS 23 rue Becquerel 67087 Strasbourg France Laboratoire Image et Ville ERL 7230 CNRS-UdS 3 rue de l'Argonne 67000 Strasbourg France

Wild animals use their habitat according to ecological pressures such as predation, resource availability or tempera- ture, yet little is known about how individuals use their environment in semi free-ranging conditions. We assessed whether a semi-free ranging group of Tonkean macaques Macaca tonkeana used its wooded parkland in a heterogeneous way. GIS and GPS were used to determine whether individuals adjusted their behaviors according to variation in environmental constraints over time of day and the course of a year. We demonstrated that social and resting activities occurred in high altitude areas and areas with a high density of bushes, whereas the group foraged in areas where the density of bushes and grass was low. In general, the animals used areas exposed to the sun that were not on a slope. Semi-free ranging Tonkean macaques seemed to behave like their wild counterparts in terms of activity budget, land use per activity and thermoregulation

关键词： GPS GIS Temperature Topography Activity budget Spatial autocorrelation Primates

Microstructure Characteristics and Mechanical Properties of Nb-17Si-23Ti Ternary Alloys Fabricated by In Situ Reaction Laser Melting deposition

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Acta Metallurgica Sinica(English Letters) 2018年第4期31卷 362-370页

作者： Wei Liu Hua-Ping Xiong Neng Li Shao-Qing Guo Ren-Yao Qin 3d Printing Research and Engineering Technology Center Beijing Institute of Aeronautical MaterialsBeijing 100095China

Fabrication of ternary Nb-17Si-23Ti alloys was attempted by in situ reaction laser melting deposition（LMd）with dual powder feeding method from Nb-28 at.% Ti powder mixture and pure Si *** microstructures of the as-deposited alloys were examined with scanning electronic microscope,and the phase constituents were analyzed by X-ray energy-dispersive spectrometer and X-ray ***,the effect of laser power on microstructure charac-teristics,microhardness and indentation fracture toughness was also *** in situ reaction LMd process resulted in remarkable refinement of the *** as-deposited samples mainly consisted of Nbss,metastable（NbTi）3Si and Ti-rich *** the increase in the laser power from 1000 to 2000 W,the Nbss morphology changed from discontinuous dendritic to near equiaxed,but the Ti-rich Nbss phase tended to ***,with the increase in the laser power,the microhardness of as-deposited samples increased from 822 to 951 HV,while the indentation fracture toughness was improved from 12.3 to 14.1 MPa mt/*** corresponding mechanism is also discussed.

关键词： Nb-Si-Ti alloys Laser melting deposition Microstructure Mechanical properties In situreaction

Long-lived Paleotethyan pelagic remnant inside Shan-Thai Block:Evidence from radiolarian biostratigraphy

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Science China Earth Sciences 2004年第12期47卷 1113-1119页

作者： Chongpan Chonglakmani dietrich Helmcke Rucha Ingavat-Helmcke School of Geotechnology Suranaree University of TechnologyNakhon RatchasimaThailandCenter of GeosciencesUniversity of GottingenGoldschmidtstr.3D-37077 GottingenGermany Center of GeosciencesUniversity of GottingenGoldschmidtstr.3D-37077 GottingenGermany

Newly identified radiolarians from ribbon chert in the Mae Hong Son-Mae Sariang area, northwestern Thailand covered Early Carboniferous, Late Permian, and Middle-Late Triassic in age, which indicate that there was a pelagic basin during the Late Paleozoic and Triassic in this region together with the published radiolarian biostratigraphic data. This basin is joined with the Chiang dao and Changning-Menglian oceanic basins, which represent the main oceanic basin of Paleotethyan Archipelago Ocean. The main oceanic basin was situated in the traditional “Shan-Thai Block”. Therefore, “the Shan-Thai Block” was not a single block during that stage, but composed of the Paleotethyan Ocean and two continental terranes that affiliated to Gondwana and Cathysian domains respectively. Keywords Late Paleozoic and Triassic - Radiolarian - northwest Thailand - Shan-Thai Block - Paleotethys

关键词： Late Paleozoic and Triassic, radiolarian, northwest Thailand, Shan-Thai Block, Paleotethys.

deciphering fluid inclusions in high-grade rocks

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Geoscience Frontiers 2014年第5期5卷 683-695页

作者： Alfons van den Kerkhof Andreas Kronz Klaus Simon Geowissenschaftliches Zentrum der Universitat Gottingen Goldschmidtstr.1-3 D 37073 GottingenGermany

The study of fluid inclusions in high-grade rocks is especially challenging as the host minerals have been normally subjected to deformation, recrystallization and fluid-rock interaction so that primary in- clusions, formed at the peak of metamorphism are rare. The larger part of the fluid inclusions found in metamorphic minerals is typically modified during uplift. These late processes may strongly disguise the characteristics of the ＂original＂ peak metamorphic fluid. A detailed microstructural analysis of the host minerals, notably quartz, is therefore indispensable for a proper interpretation of fluid inclusions. Cathodoluminescence （CL） techniques combined with trace element analysis of quartz （EPMA, LA- [CPMS） have shown to be very helpful in deciphering the rock-fluid evolution. Whereas high-grade metamorphic quartz may have relatively high contents of trace elements like Ti and A1, low- temperature re-equilibrated quartz typically shows reduced trace element concentrations. The result- ing microstructures in CL can be basically distinguished in diffusion patterns （along microfractures and grain boundaries）, and secondary quartz formed by dissolution-reprecipitation. Most of these textures are formed during retrograde fluid-controlled processes between ca. 220 and 500 ℃, i.e. the range of semi-brittle deformation （greenschist-facies） and can be correlated with the fluid inclusions. In this way modified and re-trapped fluids can be identified, even when there are no optical features observed under the microscope.

关键词： Fluid inclusionsGranuliteCharnockiteCathodoluminescenceLA-ICPMSQuartz

design and 3d Printing of Scaffolds and Tissues

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Engineering 2015年第2期1卷 261-268页

作者： Jia An Joanne Ee Mei Teoh Ratima Suntornnond Chee Kai Chua Singapore Centre for 3d Printing School of Mechanical and Aerospace Engineering Nanyang Technological University

A growing number of three-dimensional(3d)-print- ing processes have been applied to tissue engineering. This paper presents a state-of-the-art study of 3d-printing technologies for tissue-engineering applications, with particular focus on the development of a computer-aided scaffold design system; the direct 3d printing of functionally graded scaffolds; the modeling of selective laser sintering(SLS) and fused deposition modeling(FdM) processes; the indirect additive manufacturing of scaffolds, with both micro and macro features; the development of a bioreactor; and 3d/4d bioprinting. Technological limitations will be discussed so as to highlight the possibility of future improvements for new 3d-printing methodologies for tissue engineering.

关键词： rapid prototyping 3d printing additive manufacturing tissue engineering bioprinting

PARALLEL STABILIZATION

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Chinese Annals of Mathematics,Series B 1999年第1期20卷 29-38页

作者： J. L. LIONS(College de france,3,red’Ulm,75231 Paris Cedex 05,France) Collége de France 3 rue d'Ulm 75231 Paris Cedex 05 France

A new algorithm for the stabilization or (possibly turbulent, chaotic) distributed systems,governed by linear or non linear systems of equations is *** SPA (Stabilization Parallel Algorithm) is based on a systematic parallel decompositionof the problem (related to arbitrarily overlapping decomposition of domains) and on a *** is presented here for the case of linear parabolic equations, with distributed or boundarycontrol. It extends to practically all linear and non linear evolution equations, as it will bepresented in several other publications.

关键词： SPA Linear parabolic equation distributed system

Representation and Organization for Spatial data in LBS

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Journal of Earth Science 2014年第3期25卷 544-549页

作者： Yanhui Wang Yue Li Key Lab of 3d Information Collection and Application of Ministry of Education Capital Normal University

Aiming at the special demand on SVG_based representation and organization for spatial data in location based services（LBS）, the research is made in this article on the conversion method from multiple formats to SVG format, and a harris_corner detector method is proposed and verified to evaluate the conversion result. Based on the above, an optimized compression arithmetic is proposed, which integrated the characteristic of code simplification and GZIP compression. The test shows that the techniques on conversion and compression are feasible, which means that SVG_based representation is suited for spatial data in LBS and the improved compression arithmetic is prior to the former.

关键词： location based services(LBS) scalable vector graphic(SVG) conversion method harris_corner detector optimized compression arithmetic.

A Finite Element Based Study on Lowering Operation of Subsea Massive Structure

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China Ocean Engineering 2017年第5期31卷 646-652页

作者： WANG Fa-cheng WANG Jun TANG Ke department of Civil Engineering Tsinghua University COTEC Offshore Engineering solutions

Subsea production system has been increasingly used in recent South China Sea offshore developments. With deepwater applications, constituent parts of subsea systems become more complicated and enlarged. Increases on the weight and geometry of each component bring challenges to installations. A recent accomplished deployment on a subsea massive jumper shows the weight and length have been up to 120 tons and 90 m, respectively with sophi- sticated geometry. It is considerably difficult to install heavy and large subsea structures, especially in South China Sea where severe environmental conditions are common. In addition, deepwater deployment may alter natural frequency of the hoisting system and the altered frequency may be close to possible environmental conditions. To deal with the above two issues, traditionally, engineers need to carry out series of complicated numerical analyses which are on case basis and significantly time-consuming. Existing studies focus on the optimization on analysis techniques by conducting laboratory testing and numerical simulations. However, easy-to-use guidance on massive subsea structure installation are somewhat limited. The studies presented in this paper aim to achieve a simplified guidance which can briefly screen the cases subject to axial resonance and provide visible correlations between hoisting system integrity and key installation parameters.

关键词： subsea massive saucture sensitivity analysis dAF