柴北缘鱼卡地区中侏罗统石门沟组含煤层段沉积有机相分析

柴达木盆地北缘鱼卡地区中侏罗统石门沟组含煤段中发育有油页岩、煤、碳质泥岩和泥岩等富有机质细粒沉积.为了研究其沉积有机相的类型及煤和油页岩形成的控制因素,本文通过岩心观察、工业分析结合有机地球化学测试分析等方法将含煤段细粒沉积物划分为了类型A(三角洲平原沉积环境)、B(三角洲前缘-浅湖沉积环境)、C1(湖沼非油页岩亚相)及C2(湖沼油页岩亚相)四种类型,其中类型C1沉积物中发育煤,类型C2中发育油页岩,且煤较油页岩具有更高的含油率、水分、挥发分以及发热量值.有机质类型特征方面,沉积有机相类型A、B及C1沉积物有机质类型均为Ⅱ2-Ⅲ型、有机质来源均以陆源和混合来源两种有机质来源为主,而类型C2中主要为Ⅱ2型,以混合有机质来源为主;类型A及C2其沉积物有机质均处于未成熟阶段,而类型B和C1中有机质均处于未成熟-低成熟阶段;有机质保存条件方面,类型A沉积物主要形成于缺氧的淡水环境,类型B主要形成于贫氧-缺氧的淡水-半咸水环境,类型C1形成于贫氧-缺氧的淡水-半咸水环境,而类型C2则主要形成于缺氧的淡水-半咸水环境.其中类型B较类型A,类型C2较类型C1,其沉积物均形成于更为还原且盐度更高的水体环境中.石门沟组含煤段是煤和油页岩的形成层位,稳定的沉积环境、丰富的湖泊有机质来源、良好的保存条件及较少的陆源碎屑的稀释共同促进了类型C2中油页岩的形成,而丰富的陆源植物供给及良好的保存条件则促进了类型C1中煤层的形成.     

BCC_AVIM陆面过程模式冻融过程参数化的改进与检验

In this paper, considering the importance of the freezing-thawing process to the land-atmosphere interaction, and referring to the research and works on the parameterization scheme of the freeze-thaw process by domestic and foreign scholars, the parameterization scheme of the freezing-thawing process of the BCC_AVIM land surface process model is improved and vitrificated. The improvements mainly include:(1)adding the concept of supercooled water, improving soil freezing judgment conditions and updating standards for ice content;(2)adding the concept of equilibrium temperature to replace the constant freezing temperature in the original scheme;(3)Adding the impermeable fraction in hydraulic conductivity’s parameterization scheme. The modified and original schemes were used to simulate the two freeze-thaw processes of Maqu Station in 2018-2019 and 2019-2020 respectively. Comparing with the original scheme during the freezing and thawing process, it is found that modified scheme(1)increase the simulation of temperature in the frozen state, also reduce the temperature’s amplitude, and change the trend closer to the measurement data;(2)increase the simulation of water content in the frozen state, and the trend of water content of modified scheme has a better correlation with the measurement data;(3)delay the date of ice generation in the soil, advance the melting date of ice, and decrease the simulation of maximum ice content;(4)The simulation of the transition date at each stage of the freeze-thaw process is closer to the actual measurement;(5)The new scheme has a better simulation improvement effect for strong freeze-thaw years than weak freeze-thaw years. © 2022 Authors. All rights reserved.     

渤海湾老狼坨子海岸带^14C,^137Cs、^210Pb测年与现代沉积速率的加速趋势

通过对渤海湾西岸L剖面中同一关键层的碳酸钙和原生腹足类壳债权的^14C测年对比研究,确定了晚全新世的2800cal BP的层位及沉积速率0.045cm/a;8个样柱的^137Cs和^210Pbex强度、蓄积量揭示了距今约120年来堤后盐沼的平均沉积速率约为0.35cm/a,而面向开放海湾的潮坪上部则达到约2-3cm/a。研究区近1个世纪以来沉积速率的加速趋势,是渤海湾西岸泥质海岸带的特征之一。     

The origin of organic matter in the solar system: evidence from the interplanetary dust particles

The detailed examination of meteorites and interplanetary dust particles provides an opportunity to infer the origin of the organic matter found in primitive Solar System materials. If this organic matter were produced by aqueous alteration of elemental (graphitic or amorphous) carbon on an asteroid, then we would expect to see the organic matter occurring preferentially in interplanetary materials that exhibit evidence of aqueous activity, such as the presence of hydrated silicates. On the other hand, if the organic matter were produced either during the nebula phase of Solar System evolution or in the interstellar medium, we might expect this organic matter to be incorporated into the dust as it formed. In that case pre-biotic organic matter would be present in both the anhydrous and the hydrated interplanetary materials. We have performed carbon X-ray absorption near-edge structure spectroscopy and infrared spectroscopy on primitive anhydrous and hydrated interplanetary dust particles (IDPs) collected by NASA from the Earth's stratosphere. We find that organic matter is present in similar types and abundances in both the anhydrous and the hydrated IDPs, and, in the anhydrous IDPs some of this organic matter is the “glue” that holds grains together. These measurements provide the first direct, experimental evidence from the comparison of extraterrestrial samples that the bulk of the pre-biotic organic matter occurs in similar types and abundances in both hydrated and anhydrous samples. This indicates that the bulk of the pre-biotic organic matter in the Solar System did not form by aqueous processing, but, instead, had already formed at the time that primitive, anhydrous dust was being assembled. Thus, the bulk of the pre-biotic organic matter in the Solar System was formed by non-aqueous processing, occurring in either the Solar nebula or in an interstellar environment. Aqueous processing on asteroids may have altered this pre-existing organic matter, but such processing did not affect in any substantial way the C=O content of the organic matter, the aliphatic C-H abundance, or the mean aliphatic chain length.     

Cultures monoalgales: courte description et discussion d'une méthode permettant une observation à fort grossissement des cellules avant leur isolement à l'aide d'un emporte-pièce

A method allowing isolation of phytoplancton algae for unialgal cultures is briefly described. Advantages and limits of the method are discussed.     

Variation in Coronal Activity from Solar Cycle 24 Minimum to Maximum Using Three-Dimensional Reconstructions of the Coronal Electron Density from STEREO/COR1

Three-dimensional electron density distributions in the solar corona are reconstructed for 100 Carrington rotations (CR 2054?–?2153) during 2007/03?–?2014/08 using the spherically symmetric method from polarized white-light observations with the inner coronagraph (COR1) onboard the twin Solar Terrestrial Relations Observatory (STEREO). These three-dimensional electron density distributions are validated by comparison with similar density models derived using other methods such as tomography and a magnetohydrodynamics (MHD) model as well as using data from the Solar and Heliospheric Observatory (SOHO)/Large Angle and Spectrometric Coronagraph (LASCO)-C2. Uncertainties in the estimated total mass of the global corona are analyzed based on differences between the density distributions for COR1-A and -B. Long-term variations of coronal activity in terms of the global and hemispheric average electron densities (equivalent to the total coronal mass) reveal a hemispheric asymmetry during the rising phase of Solar Cycle 24, with the northern hemisphere leading the southern hemisphere by a phase shift of 7?–?9 months. Using 14 CR (\(\approx13\)-month) running averages, the amplitudes of the variation in average electron density between Cycle 24 maximum and Cycle 23/24 minimum (called the modulation factors) are found to be in the range of 1.6?–?4.3. These modulation factors are latitudinally dependent, being largest in polar regions and smallest in the equatorial region. These modulation factors also show a hemispheric asymmetry: they are somewhat larger in the southern hemisphere. The wavelet analysis shows that the short-term quasi-periodic oscillations during the rising and maximum phases of Cycle 24 have a dominant period of 7?–?8 months. In addition, it is found that the radial distribution of the mean electron density for streamers at Cycle 24 maximum is only slightly larger (by \(\approx30\%\)) than at cycle minimum.     

Neutron stars in the multidimensional einstein theory of gravitation

The radius, mass, total number of baryons, and other parameters of static, spherically symmetric, superdense stars are calculated. A model with one Ricci-flat inner space of arbitrary dimensionality and the approximation p₁=?0.5ε + ap for additional components of the energy — momentum tensor are used (ε and ρ are the total energy density and the pressure of the stellar matter and a is a fitting parameter). In the case of white dwarfs, the results of the multidimensional theory do not depend on the dimensionality D of space-time for ?10 ? a ? 10 and coincide with the analogous data of the general theory of relativity (GTR). For neutron stars there is a dependence on D and a. For D>4, in particular, the greatest mass M_max of a neutron star as a function of a has a maximum at 3<a(D) ? 4, which exceeds the greatest mass M _max ⁰ =2.14 M_⊙ in the GTR. A comparison of theoretical results with observational data determines the allowable values of a. Data for PSR 1913 + 16 lead to 0.2 ≤ a ≤ 9.2 in the case of D=26, while the results of [P. C. Joss and S. A. Rappaport, Annu. Rev. Astron. Astrophys.,22, 537 (1984)] lead to the stricter limits 1 ≤ a ≤ 7.4.     

Biomineralization of Uranium: A Simulated Experiment and Its Significance

A simulated experimental reduction of U^v1 and the synthesis of uraninite by a sulfate-reducing bacteria,Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were:35℃, pH=7.0-7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. Uraninite was formed on the surface of the host bacteria after a one-week‘s incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments,might have participated in the biomineralization of this uranium deposit. There is an important difference in the orderdisorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.     

Spatial data for landslide susceptibility, hazard, and vulnerability assessment: An overview

The aim of this paper is to discuss a number of issues related to the use of spatial information for landslide susceptibility, hazard, and vulnerability assessment. The paper centers around the types of spatial data needed for each of these components, and the methods for obtaining them. A number of concepts are illustrated using an extensive spatial data set for the city of Tegucigalpa in Honduras. The paper intends to supplement the information given in the “Guidelines for Landslide Susceptibility, Hazard and Risk Zoning for Land Use Planning” by the Joint ISSMGE, ISRM and IAEG Technical Committee on Landslides and Engineered Slopes (JTC-1). The last few decades have shown a very fast development in the application of digital tools such as Geographic Information Systems, Digital Image Processing, Digital Photogrammetry and Global Positioning Systems. Landslide inventory databases are becoming available to more countries and several are now also available through the internet. A comprehensive landslide inventory is a must in order to be able to quantify both landslide hazard and risk. With respect to the environmental factors used in landslide hazard assessment, there is a tendency to utilize those data layers that are easily obtainable from Digital Elevation Models and satellite imagery, whereas less emphasis is on those data layers that require detailed field investigations. A review is given of the trends in collecting spatial information on environmental factors with a focus on Digital Elevation Models, geology and soils, geomorphology, land use and elements at risk.