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Model test of the influence of cyclic water level fluctuations on a landslide

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Journal of Mountain Science 2020年第1期17卷 191-202页

作者： HE Chun-can HU Xin-li XU Chu WU Shuang-shuang ZHANG Han LIU Chang faculty of Engineering China University of Geosciences

Many landslides in reservoir areas continuously deform under cyclic water level fluctuations due to reservoir operations. In this paper,a landslide model, developed for a typical colluvial landslide in the Three Gorges Reservoir area, is used to study the effect of cyclic water level fluctuations on the landslide. Five cyclic water level fluctuations were implemented in the test, and the fluctuation rate in the last two fluctuations doubled over the first three fluctuations. The pore water pressure and lateral landslide profiles were obtained during the test. A measurement of the landslide soil loss was proposed to quantitatively evaluate the influence of water level fluctuations. The test results show that the first water level rising is most negative to the landslide among the five cycles. The fourth drawdown with a higher drawdown rate caused further large landslide deformation. An increase of the water level drawdown rate is much more unfavorable to the landslide than an increase of the water level rising rate. In addition, the landslide was found to have an adaptive ability to resist subsequent water level fluctuations after undergoing large deformation during a water level fluctuation. The landslide deformation and observations in the field were found to support the test results well.

关键词： Reservoir landslide Cyclic water level fluctuations Physical model test Landslide soil loss Adaptive ability

An Innovative Approach to Separate Iron Oxide Concentrate from High-sulfur and Low-grade Pyrite Cinders

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Journal of Iron and Steel Research International 2016年第8期23卷 756-764页

作者： Yong LI Fu-chun ZHOU Zhao-xin ZHOU Zhi-han TIAN Chao YANG Xi-ke TIAN faculty of Materials Science and Chemistry China University of Geosciences

High-sulfur and low-grade pyrite cinders are the waste products of sulfuric acid manufacturing *** valuable components,such as iron oxide,are contained in pyrite cinders and difficult to be separated and purified just via the high temperature roasting *** this,an innovative method including water-washing,aqua regia leaching,hydrothermal alkali activation and acid-washing was *** the effects of different parameters on recovery efficiency of iron oxide were systematically *** optimum parameters were proposed as follows：water rinse-leaching at room temperature for 5-20 min,and melting at 160 ℃ for 2.0h with NaOH（concentration of 30mass%）,followed by leaching with aqua regia solution（3.0vol.%）for *** the treatment,the content of iron oxides increased from 54.3to 96.0mass% with the recovery rate exceeding 85%.Meanwhile,calcium sulphate was recovered as the high value-added products by alkali extraction ***,the phase transformation and microstructure of the samples in the process were studied by physicochemical methods to reveal the separation mechanisms of different components in the pyrite cinders.

关键词： sulfur leaching contained alkali regia pyrite recovered hydrothermal systematically leached

Analysis of network traffic flow dynamics based on gravitational field theory

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Chinese Physics B 2013年第6期22卷 670-680页

作者：刘刚李永树张喜平 faculty of geosciences and environmental Engineering Southwest Jiaotong University

For further research on the gravity mechanism of the routing protocol in complex networks, we introduce the concept of routing awareness depth, which is represented by p. On this basis, we define the calculation formula of the gravity of the transmission route for the packet, and propose a routing strategy based on the gravitational field of the node and the routing awareness depth. In order to characterize the efficiency of the method, we introduce an order parameter, η, to measure the throughput of the network by the critical value of phase transition from free flow to congestion, and use the node betweenness centrality, B, to test the transmission efficiency of the network and congestion distribution. We simulate the network transmission performance under different values of the routing awareness depth, ρ. Simulation results show that if the value of the routing awareness depth p is too small, then the gravity of the route is composed of the attraction of very few nodes on the route, which cannot improve the capacity of the network effectively. If the value of the routing awareness depth ρ is greater than the network＇s average distance （l）, then the capacity of the network may be improved greatly and no longer change with the sustainable increment of routing awareness depth p, and the routing strategy performance enters into a constant state. Moreover, whatever the value of the routing awareness depth p, our algorithm always effectively balances the distribution of the betweenness centrality and realizes equal distribution of the network load.

关键词： routing strategy congestion gravitation field complex networks

Permian–Triassic Conodonts from Dajiang(Guizhou, South China) and Their Implication for the Age of Microbialite Deposition in the Aftermath of the End-Permian Mass Extinction

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Journal of Earth Science 2014年第3期25卷 413-430页

作者： Haishui Jiang Xulong Lai Yadong Sun Paul B Wignall Jianbo Liu Chunbo Yan State Key Laboratory of Biogeology and environmental Geology China University of Geosciences faculty of Earth Sciences China University of Geosciences School of Earth and environment University of Leeds School of Earth and Space Sciences Peking University

The widespread microbialites deposition that followed the End-Permian mass extinction in the Tethyan realm have been intensively studied because of the evidence they provide on the nature of this crisis and its aftermath. However, the age of the microbialite event remains controversial. New conodont collection across the Permian–Triassic（P–T） transition from Dajiang（Guizhou Province, South China） in this study enable us to discriminate four conodont zones, in ascending order, they are： Hindeodus parvus zone, Isarcicella lobata zone, Isarcicella isarcica zone and Hindeodus sosioensis zone. The age of microbialite in the P–T transition at the Dajiang Section is considered to be within the Hindeodus parvus zone and thus to clearly post-date the main extinction crisis. Reviewing the age of onset of microbialites throughout the Tethyan regions reveals two different ages： a Hindeodus changxingensis zone age is dominant in south-western and westernmost Tethys, whilst most other regions show microbialite deposition began in the Hindeodus parvus zone. Our investigation also indicates that two conodont changes occur at this time： an increase of hindeodid species immediately following a sequence boundary and the mass extinction, and a phase of extinction losses in the earliest Triassic Isarcicella isarcica zone during highstand development.

关键词： Permian–Triassic conodont Dajiang microbialite mass extinction.

Microstructure and magnetic fabric in the Shuanghe pluton:A synkinematic granite in Eastern Dabie Mountains,China

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Science China Earth Sciences 2004年第10期47卷 912-919页

作者： YANG Kunguang LIU Qiang LIU Yuyan MA Changqian XU Yajun YANG Kuifeng faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China

Strain analyses for the Shuanghe pluton show that the main strain planes suffered distinct deformation. The main strain value (XZ) is up to 1.59–2.18, and the value of Flinn index (K) ranges from 0.11 to 0.82. Anisotropy of magnetic susceptibility (AMS) measurements reveal that the orientations of the magnetic foliation and lineation gently dip SE, consistent with the macroscopic foliation of the pluton. The value of anisotropy degree (P) ranges from 1.109 to 1.639, and the shape parameter (T) from 0.079 to 0.534. These studies prove that the pluton was deformed under strong compression. Quartz c-axis textures, defined by monoclinic or triclinic asymmetry, usually developed the high maxima paralleling the b-axis, which is defined by the prismatic slip (1010) under the high temperature. These fabrics are quite different from those developed in the high-ultrahigh pressure rocks (UHP) which were captured in the pluton or country rocks. It is concluded that the Shuanghe pluton emplaced under regional compression slightly after the formation of UHP, and it is characterized by synkinematic granitic deformation.

关键词： strain analysis, anisotropy of magnetic susceptibility (AMS), quartz c-axis fabric, synkinematic granite,Dabie Mountains.

Alteration Information Extraction by Applying Synthesis Processing Techniques to Landsat ETM+Data: Case Study of Zhaoyuan Gold Mines, Shandong Province, China

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Journal of China University of geosciences 2007年第1期18卷 72-76页

作者：刘福江吴信才孙华山郭艳 School of the Earth Sciences and Resources China University of Geosciences faculty of Information Engineering China University of Geosciences Wuhan 430074 China faculty of Information Engineering China University of Geosciences faculty of Earth Resources China University of Geosciences School of Computer China University of Geosciences

Satellite remote sensing data are usually used to analyze the spatial distribution pattern of geological structures and generally serve as a significant means for the identification of alteration zones. Based on the Landsat Enhanced Thematic Mapper （ETM＋） data, which have better spectral resolution （8 bands） and spatial resolution （15 m in PAN band）, the synthesis processing techniques were presented to fulfill alteration information extraction： data preparation, vegetation indices and band ratios, and expert classifier-based classification. These techniques have been implemented in the MapGIS-RSP software （version 1.0）, developed by the Wuhan Zondy Cyber Technology Co., Ltd, China. In the study area application of extracting alteration information in the Zhaoyuan （招远） gold mines, Shandong （山东） Province, China, several hydorthermally altered zones （included two new sites） were found after satellite imagery interpretation coupled with field surveys. It is concluded that these synthesis processing techniques are useful approaches and are applicable to a wide range of gold-mineralized alteration information extraction.

关键词： alteration information extraction Zhaoyuan gold mines Landsat-7 ETM+ data

Genetic interpretation of fish swimming trails and calculation of fish-body length in Late Triassic Hengshan, Shannxi Province, China

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Science China Earth Sciences 2004年第3期47卷 272-279页

作者： LU Zongsheng HOU Jianxiang CHEN Bin HAO Chaokun LI Xiaoyan faculty of Earth Sciences China University of Geosciences Wuhan430074 China Faculty of Earth Sciences China University of Geosciences Wuhan430074 China Faculty of Earth Sciences China University of Geosciences Wuhan430074 China Faculty of Earth Sciences China University of Geosciences Wuhan430074 China Faculty of Earth Sciences China University of Geosciences Wuhan430074 China

The fish swimming trail fossils are rare and, therefore, precious. The specimen de-scribed abroad are generally smaller or more poorly preserved. The specimens used in the pre-sent study and derived from the Mesozoic strata in Hengshan County, Shaanxi Province, China, are rare because of their completeness (with the length of the specimen reaching 4 m), exquisiteness and largeness in trace body. These specimens, classified as four ichnospecies, including two new ones, show the morphological pattern of the fish swimming trails. The trace fish bodies are calculated to be 32—92 cm long.

关键词： fish swimming trails, calculation of fish-body length, Late Triassic, Shaanxi Province.

Size variation of the end Permian conodont Neogondolella at Meishan Section,Changxing,Zhejiang and its significance

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Science China Earth Sciences 2006年第4期49卷 337-347页

作者： LUO Genming LAI Xulong JIANG Haishui ZHANG Kexin faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China

This study is based on both a generic and species level investigation of the individual size of the latest Permian conodont Neogondolella Pa elements collected from Meishan Section A, Changxing, Zhejiang Province. In this study, an obvious size reduction of Neogondolella Pa elements within bed 24e of the upper Changxing Limestone is recognized. The size variation of the Neogon- dolella occurs simultaneously with some important events including the negative shift of δ 13C, change in the ratio of the abundance of cyanobacterial biomarkers versus that of other general bacterial biomarkers and the shallowing of the sea water. Through the investigation of the paleoenvironmental changes and the analysis of the paleoecology of the conodont genus Neogondolella, the authors propose that the major factors for the size reduction of species of the conodont genus Neogondolella are food shortages caused by the mass extinction, the shallowing of the sea water as well as the in- crease in opacity of the sea water during the end Permian. The same phenomenon of Neogondolella size reduction is also observed in preliminary research from the same horizon at Shangsi Section, Sichuan Province. All the evidence suggests that there was a mass extinction that occurred at the horizon of bed 24e, and the evidence supports the viewpoint of a multi-phase mass extinction during the Permian and Triassic transition in South China.

关键词： Meishan Section, end Permian, conodont, Neogondolella, size reduction.

Paleoecology of the Ordovician Reef-Shoal Depositional System in the Yijianfang Outcrop of the Bachu Area,West Tarim Basin

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Journal of Earth Science 2012年第4期23卷 408-420页

作者：焦养泉吴立群荣辉王永标王瑞 Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education China University of Geosciences faculty of Earth Resources China University of Geosciences faculty of Earth Sciences China University of Geosciences College of geosciences China University of Petroleum

The reef-shoal depositional system of the Ordovician carbonate platform margin is well exposed in the Yijianfang （一间房） outcrop of the Bachn （巴楚） uplift region, which offers an advantageous condition to study their paleoecology. Using a detailed field geologic survey and illustrated profiles of typical depositional systems, three types of genetic facies associations can be recognized in the reef-shoal depositional system： an organic reef, an organic shoal, and an upper slope. The organic reef is composed of three types of genetic facies （a reef base, a reef core, and fore-reef breccias）; the organic shoal is formed from five types of genetic facies （tide channels, fore-reef inner shoals, fore-reef outer shoals, back-reef inner shoals, and back-reef outer shoals）. The studies of the paleontological assemblage in each genetic facies of the depositional system indicate that the fauna preserved in each genetic facies are varied. The calathium, archaeoscyphia, bryozoan, and calcareous alga are well preserved in the organic reefs. The organisms preserved in the organic shoals are generally fragmented, while weil-preserved girvanella and nuia siberica with a content of about 15% in the back-reef outer shoals are the most characteristic and different from others. The sinoceras, trilobites, and gastropods are well preserved in the upper slope deposits. The studies will demonstrate that the reef-shoal complexes developed above the base of the fair-weather wave base and that the original hydrodynamic conditions for the reef core forming is the stronger and become more and more low-energy from the inner part to outer part of the organic shoals.

关键词： paleoecology reef-shoal depositional system Ordovician Tarim basin.