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East Asia Winter Monsoon changes inferred from environmentally sensitive grain-size component records during the last 2300 years in mud area southwest off Cheju Island,ECS

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Science China Earth Sciences 2006年第6期49卷 604-614页

作者： Yoshiki Saito Geological Survey of Japan Tsukuba Ibaraki 305-8567 Japan

Environmentally sensitive grain-size component (ESGSC) extracted from grain-size data of a sediment core B2, which were retrieved from mud area southwest off Cheju Island (MACI), East China Sea (ECS), can be used to indicate the variations of East Asia Winter Monsoon (EAWM), with high (low) content/mean-size of ESGCS denote to strong (weak) EAWM. Combined with AMS14C datings core B2 provides a continuous high-resolution record of EAWM changes over the past 2300 years, with an average resolution of 13 years. The results show that the variations of EAWM are con-sistent with temperature changes inferred from historical documents in eastern China over the past 2300 years, from which four climate stages may be identified. In stages before 1900 aBP (50 AD) and 1450―780 aBP (50―1170 AD) the EAWM were comparatively weak, corresponding to warm climate periods in eastern China, respectively. And in stages of 1900―1450 aBP (50―500 AD) and 780―219 aBP (1170―1731 AD) the EAWM were strongly developed, which correspond well to climate changes of two cold periods in eastern China. It is also shown from this study that the stage at 780―219 aBP (1170―1731 AD) was the coldest climate period during the last 2300 years and could be, therefore, related to the Little Ice Age (LIA). Climatic fluctuations appeared obviously in all the four stages, and two climate events of abrupt changes from warm to cold occurred at around 1900 aBP (50 AD) and 780 aBP (1170 AD), of which the latter is probably related to globe-scale changes of atmospheric circulation at that time.

关键词： East China Sea, mud area, environmentally sensitive grain-size component, East Asia Winter Monsoon, Little Ice Age, Late Holocene.

3-D network model and its parameter calibration

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Science China Mathematics 2002年第10期45卷 1351-1360页

作者：刘晓宇梁乃刚李敏 Stt. Key Lab. of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

A material model, whose framework is parallel spring-bundles oriented in 3-D space, is proposed. Based on a discussion of the discrete schemes and optimum discretization of the solid angles, a 3-D network cell consisted of one-dimensional components is developed with its geometrical and physical parameters calibrated. It is proved that the 3-D network model is able to exactly simulate materials with arbitrary Poisson ratio from 0 to 1/2, breaking through the limit that the previous models in the literature are only suitable for materials with Poisson ratio from 0 to 1/3. A simplified model is also proposed to realize high computation accuracy within low computation cost. Examples demonstrate that the 3-D network model has particular superiority in the simulation of short-fiber reinforced composites.

关键词： strain energy stiffness modulus, orientation component, network model, poisson ratio.

Molecular and carbon isotopic compositions of gas inclusions of deep carbonate rocks in the Tarim Basin

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Science China Earth Sciences 2004年第5期47卷 445-452页

作者： Paul Farrimond Fossil Fuels and Environmental Geochemistry Drummond Building University of Newcastle upon Tyne Newcastle upon Tyne NE17RU UK

Gaseous components of gas inclusions in deep carbonate rocks (>5700 m) from the Tacan 1 well were analyzed by online mass spectrometry by means of either the stepwise heat-ing technique or vacuum electromagnetism crushing. The carbon isotopic compositions of gases released by vacuum electromagnetism crushing were also measured. Although the molecular compositions of gas inclusions show differences between the two methods, the overall charac-teristics are that gas inclusions mainly contain CO2, whilst hydrocarbon gases, such as CH4, C2H6 and C3H8, are less abundant. The content of CO is higher in the stepwise heating experi-ment than that in the method of vacuum electromagnetism crushing, and there are only minor amounts of N2, H2 and O2 in gas inclusions. Methane d 13C values of gas inclusions in Lower Ordovician and Upper Cambrian rocks (from 5713.7 to 6422 m; -52—63) are similar to those of bacterial methane, but their chemical compositions do not exhibit the dry character in comparison with biogenic gases. These characteristics of deep gas inclusions may be related to the migration fractionation. Some deep natural gases with light carbon isotopic characteristics in the Tazhong Uplift may have a similar origin. The d 13C1 values of gas inclusions in Lower Cam-brian rocks (7117—7124 m) are heavier (-39), consistent with highly mature natural gases. Carbon isotopic compositions of CO2 in the gas inclusions of deep carbonate rocks are similar (from -4 to 13) to those of deep natural gases, indicating predominantly an inorganic origin.

关键词： Tarim Basin, deep carbonate rock, gas inclusion component, carbon isotope.

^(13)C NMR spectra of tectonic coals and the effects of stress on structural components

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Science China Earth Sciences 2005年第9期48卷 1418-1437页

作者： JU Yiwen1,2, JIANG Bo1, HOU Quanlin2, WANG Guiliang1 & NI Shanqin2 1. College of Mineral Resource and Geosciences, China University of Mining and Technology, Xuzhou 221008, China 2. Laboratory of Computational Geodynamics, College of Geosciences, Graduate School of Chinese Academy of Sciences, Beijing 100049, China College of Mineral Resource and Geosciences China University of Mining and Technology Xuzhou China Laboratory of Computational Geodynamics College of Geosciences Graduate School of Chinese Academy of Sciences Beijing China

High-resolution 13C Nuclear Magnetic Resonance (NMR) spectra of different kinds of tectonic coals were obtained using the NMR (CP/MAS+TOSS) method. On the basis of this, after simulation synthesis and division of spectra, the relative contents of carbon functional groups were calculated. Combined with results of Ro, max, XRD testing and element analysis, stress effects on the composition of macromolecular structures in tectonic coals were studied further. The results showed that Ro, max was not only the important index for describing coal rank, but was also effective for estimating the stress effect of tectonic coals. Under tectonic stress ac- tion, Ro, max was the most direct indicator of the coal structure and chemical components. Changes in the stacking Lc of the coal basic structure unit (BSU) and La/Lc parameters could distinguish the temperature and stress effects on metamorphic-deformed environments, and re- flected the degree of structural deformation. Therefore, on the whole, Lc and La/Lc can be used to index of the degree of structural deformation of tectonic coals. In different metamorphic and de- formed environments, different kinds of tectonic coals are formed under structural stress. The changes in characteristics of the macromolecular structure and chemical composition are such that as the increase in structural deformation becomes stronger, from the brittle deformation coal to ductile deformation coal, the ratio of width at the half height of the aromatic carbon and ali- phatic carbon peaks (Hfa/Hfal ) was increased. As carbon aromaticity was raised further, carbon aliphaticity reduced obviously and different compositions of macromolecular structure appeared as a jump and wave pattern except for in wrinkle structure coal, which might result chiefly from stress effects on the macromolecular structure of different kinds of tectonic coals. The macro- moecular changes of wrinkle structure coal are reflected mainly on physical structure. In the metamorphi

关键词： tectonic coal, NMR, macromolecular structure, chemical component, stress effect.

Simultaneous optimal estimates of fixed effects and variance components in the mixed model

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Science China Mathematics 2004年第5期47卷 787-799页

作者： WU Mixia WANG Songgui College of Applied Sciences Beijing University of Technology Beijing 100022 College of Applied Sciences Beijing University of Technology Beijing 100022

For a general linear mixed model with two variance components, a set of simple conditions is obtained, under which, (i) the least squares estimate of the fixed effects and the analysis of variance (ANOVA) estimates of variance components are proved to be uniformly minimum variance unbiased estimates simultaneously; (ii) the exact confidence intervals of the fixed effects and uniformly optimal unbiased tests on variance components are given; (iii) the exact probability expression of ANOVA estimates of variance components taking negative value is obtained.

关键词： linear mixed model, random effect, variance component, minimum variance unbiased estimate,uniformly most powerful unbiased test.

1,1-Dibutoxybutane as a Petroleum Diesel Fuel Blendingcomponent and Their Mixture Performance

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Journal of Energy and Power Engineering 2016年第12期10卷 726-732页

作者： Yoeswono Iip Izul Falah Triyono The Education and Training Center on Oil and Gas Cepu 58315 Indonesia Department of Chemistry Gadjah Mada University Yogyakarta 55281 Indonesia

Effect of 1,1-dibutoxybutane （DBB） addition on petroleum DF （diesel fuel） performance has been studied. The study wasstarted by preparing DBB from decomposition of 1 -butanol on manganese impregnated on activated carbon （Mn/AC） catalyst at 450 ℃ in stainless steel reactor. The product was distilled at 200 ℃ and the residue obtained was analyzed by GC-MS and HSQC NMR toconfirm its structure and purity. The DBB-DF mixtures were prepared at different compositions and determined their excess molarvolume, homogeneity, phase stability, ignition quality, lubricity, cold flow quality, energy content, and viscosity. The addition of DBBinto DF formed a homogeneous mixture and had a good phase stability. The mixtures gave positive excess molar volume values overthe whole concentration ranges. The ignition quality and lubricity of the mixtures increased without lost in cold flow quality. Slightdecreased in viscosity and energy content per mass unit were observed.

关键词： 1,1-dibutoxybutane, petroleum diesel fuel, blending component, fuel mixture characteristics.

Late Mesozoic crust-mantle interaction and lower crust components in South China: A geochemical study of mafic granulite xenoliths from Cenozoic basalts

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Science China Earth Sciences 2003年第5期46卷 447-460页

作者：于津海徐夕生周新民 StateKeyLaboratoryofDepositResearch DepartmentofEarthSciencesNanjingUniversity

Mafic granulite xenoliths collected from Cenozoic basalts in SE China can be classified as magmatic granulite and cumulate granulite. Magmatic granulites are characterized by highly concentrated AI2O3, K2O, P2O5, Ba, Sr, Pb and REE, and low contents of Nb, Zr, Hf and Th, and have an incompatible element abundance pattern similar to that of continental arc basalts. Cumulate granulites are depleted in K2O, P2O5, Rb, Cs and Ba. These granulite xenoliths were the prod-ucts of crystallization and recrystallization of the basaltic magma underplating into crust-mantle boundary in Late Mesozoic. Sr and Nd isotopic compositions and variation trend of these mafic rocks are the result of crust-mantle mixing and controlled by assimilation and fractional crystallization process (AFC). However, trace element and major element variations were mainly controlled by fractional crystallization. The granulites are similar in geochemistry to surface Late Mesozoic gabbro and basalt in the study area, suggesting a close petrogenetic link between them. Late Mesozoic basaltic magma activities are the most important cause for the formation of extensive contemporaneous granite and rhyolite in the study area. This study and previous data indicate that the lower crust beneath South China is composed of a variety of Paleo- to Meso-proterozoic metamorphic rocks and Late Mesozoic mafic granulites.

关键词： granulite xenoliths, Late Mesozoic, lower crust component, AFC process, South China.