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| 1 | 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显示文摘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 The results show that the variations of EAWM are con-sistent with temperature changes inferred from historical documents in eastern China over the past 2300 years, from which four climate stages may be identified.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. | Yoshiki Saito | 2006 | Science China Earth Sciences2006，49，6： | 28 |
| 2 | ^(13)C NMR spectra of tectonic coals and the effects of stress on structural components显示文摘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 metamorphic and deformed environments of the middle and high rank coals, different kinds of tectonic coals, when compared with the metamorphic and deformed environments of low rank coal, have a greater change in Hfa/Hfal, carbon aromaticity, carbon aliphaticity and a different composition of macromolecular structure. So these parameters can be used to estimate in- creases of coal rank, and to a certain degree, the stress effects on structural components of tectonic coals. | 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 | 2005 | Science China Earth Sciences2005，48，9： | 18 |
| 3 | Late Mesozoic crust-mantle interaction and lower crust components in South China: A geochemical study of mafic granulite xenoliths from Cenozoic basalts显示文摘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 Al2O3, 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. Cumu-late granulites are depleted in K2O, P2O5, Rb, Cs and Ba. These granulite xenoliths were the products of crystallization and recrystallization of the basaltic magma underplating into crust-man-tle 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 crystalliza-tion 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 meta-morphic rocks and Late Mesozoic mafic granulites. | 于津海 徐夕生 周新民 | 2003 | Science China Earth Sciences2003，46，5： | 6 |
| 4 | Simultaneous optimal estimates of fixed effects and variance components in the mixed model显示文摘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. | WU Mixia WANG Songgui | 2004 | Science China Mathematics2004，47，5： | 6 |
| 5 | Numerical Simulation and Experiments of Hydroforming of Rectangular-section Tubular Component显示文摘In order to reduce high calibration pressure in hydroforming of components with too small radii, a method wasproposed to manufacture automotive hollow components with rectangular shape by relatively lower pressure. Theprocess is simulated and analyzed. It is thought that the friction force between the die surface and tube is a mainreason that high pressure is needed to form small radii. Using the method proposed in this paper, a petal-like sectionshape is first preformed so that the central zones of the four sides of the preform section do not contact with the diesides, thus the tube metal is easy to flow into the transition radii area in calibration stage. Moreover, a positive forcealong the sides is produced by the internal pressure, which is beneficial to overcome the friction force and push thematerial into the radii. Therefore, the pressure for forming the transition radii is greatly reduced and the componentswith small radii can be formed with relatively lower pressure. For the experimental case conducted in this paper, theforming pressure is reduced by about 28.6% than the estimated forming pressure. | Shijian YUAN Gang LIU Xianwei TIAN Z.R.WANG | 2003 | Journal of Materials Science & Technology2003，19，z1： | 5 |
| 6 | 3-D network model and its parameter calibration显示文摘A material model, whose framework is parallel spring-bundles oriented in 3-D space, isproposed. Based on a discussion of the discrete schemes and optimum discretization of the solidangles, a 3-D network cell consisted of one-dimensional components is developed with its geomet-rical and physical parameters calibrated. It is proved that the 3-D network model is able to exactlysimulate materials with arbitrary Poisson ratio from 0 to 1/2, breaking through the limit that the pre-vious models in the literature are only suitable for materials with Poisson ratio from 0 to 1/3. A sim-plified model is also proposed to realize high computation accuracy within Iow computation cost.Examples demonstrate that the 3-D network model has particular superiority in the simulation ofshort-fiber reinforced composites. | 刘晓宇 梁乃刚 李敏 | 2002 | Science China Mathematics2002，45，10： | 2 |
| 7 | Pressure and velocity cross-spectrum of normal modes in low-frequency acoustic vector field of shallow water and its application显示文摘The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow water integrated with the concept of effective depth of Pekeris waveguide is proposed, especially the active component of the pressure and horizontal particle velocity cross-spectrum, also called horizontal complex cross acoustic intensity, when only two normal modes are trapped in the waveguide. Both the approximate theoretic analysis and the numerical results show that the sign of the horizontal complex cross acoustic intensity active component is independent of the range when vertically deployed receiving dual sensors are placed in appropriate depths, the sum of which is equal to the waveguide effective depth, so it can be used to tell whether the sound source is near the surface or underwater; while the range rate is expected to be measured by utilizing the sign distribution characteristic of the reactive component. The further robustness analysis of the depth classification algorithm shows that the existence of shear waves in semi infinite basement and the change of acoustic velocity profiles have few effects on the application of this method, and the seabed attenuation will limit the detection range, but the algorithm still has a good robustness in the valid detection range. | Yun Yu Qing Ling Jiang Xu | 2015 | Journal of Systems Engineering and Electronics2015，26，2： | 2 |
| 8 | Molecular and carbon isotopic compositions of gas inclusions of deep carbonate rocks in the Tarim Basin显示文摘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. | Paul Farrimond | 2004 | Science China Earth Sciences2004，47，5： | 1 |
| 9 | 1,1-Dibutoxybutane as a Petroleum Diesel Fuel BlendingComponent and Their Mixture Performance显示文摘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. | Yoeswono Iip Izul Falah Triyono | 2016 | Journal of Energy and Power Engineering2016，10，12： | 0 |
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