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Earthquake-controlled event deposits and its tectonic significance from the Middle Permian Wandrawandian Siltstone in the Sydney Basin, Australia

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Science China Earth Sciences 2005年第9期48卷 1337-1346页

作者： DU Yuansheng1, G. R. Shi1,2.& GONG Yiming1 1. Faculty of Earth Sciences, China university of geosciences,{2., China 2. School of Ecology and Environment, Deakin university, Victoria 312., Australia Faculty of Earth Sciences China University of Geosciences Wuhan China School of Ecology and Environment Deakin University Victoria Australia

The Sydney-Bowen basin in eastern Australia is an elongate back arc-converted foreland basin system situated between the Lachlan Fold Belt in the west and the New England Fold Belt in the east. The Middle Permian Wandrawandian Siltstone at Warden Head near Ulla- dulla in the southern Sydney Basin is dominated by fossiliferous siltstone and mudstone, with a large amount of dropstones and minor pebbly sandstone beds. Two general types of deposits are recognized from the siltstone unit in view of the timing and mechanism of formation. One is rep- resented by the primary deposits from offshore to subtidal environments with abundant drop- stones of glacial marine origin. The second type is distinguished by secondary, soft-sediment deformational deposits and structures, and comprises three layers of mudstone dykes of seismic origin. In the latter type, metre scale, laterally extensive syn-depositional slump deformation structures occur in the middle part of the Wandrawandian Siltstone. The deformation structures vary in morphology and pattern, including large-scale complex-type folds, flexural stratification, concave-up structures, faulting of small displacements accompanied by folding and brecciation. The slumps and associated syn-sedimentary structures are attributed to penecontemporaneous deformations of soft sediments (mostly silty mud) formed as a result of mass movement of un- consolidated and/or semi-consolidated substrate following an earthquake event. The occurrence of the earthquake event deposits supports the current view that the Sydney Basin was located in a back-arc setting near the New England magmatic arc on an active continental margin during the Middle Permian.

关键词： Permian, seismites, earthquake, tectonics, Sydney Basin, Australia.

Seabed Classification Using BP Neural Network Based on GA

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Acta Oceanologica Sinica 2003年第4期22卷 523-531页

作者： Yang Fanlin1, Liu Jingnan2.1. GPS Engineering Research Center, wuhan university, wuhan 430079, China. 2. Presidential Secretariat, wuhan university, wuhan 430079, China GPS Engineering Research Center Wuhan University Wuhan 430079 China

Side scan sonar imaging is one of the advanced methods for seabed study. In order to be utilized in other projects, such as ocean engineering, the image needs to be classified according to the distributions of different classes of seabed materials. In this paper, seabed image is classified according to BP neural network, and. Genetic Algorithm is adopted in train network in this paper. The feature vectors are average intensity, six statistics of texture and two dimensions of fractal. It considers not only the spatial correlation between different pixels, but also the terrain coarseness. The texture is denoted by the statistics of the co-occurrence matrix. Double Blanket algorithm is used to calculate dimension. Because a uniform fractal may not be sufficient to describe a seafloor, two dimensions are calculated respectively by the upper blanket and the lower blanket. However, in sonar image, fractal has directivity, i. e. there are different dimensions in different direction. Dimensions are different in acrosstrack and alongtrack, so the average of four directions is used to solve this problem. Finally, the real data verify the algorithm. In this paper, one hidden layer including six nodes is adopted. The BP network is rapidly and accurately convergent through GA. Correct classification rate is 92.5 % in the result.

关键词： BP network co-occurrence matrix fractal classification genetic algorithin

Synthesis of todorokite by refluxing process and its primary characteristics

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Science China Earth Sciences 2004年第8期47卷 760-768页

作者： FENG Xionghan1, LIU Fan1, TAN Wenfeng1, LIU Xiangwen2.& HU Hongqing1 1. College of Resources and Environment, Huazhong Agricultural university, wuhan 430070, China 2. Testing Center, China university of geosciences, wuhan 430074, China College of Resources and Environment Huazhong Agricultural University Wuhan China Testing Center China University of Geosciences Wuhan China

Single phase and well-crystallined todorokite were synthesized by heating and refluxing process from birnessite as a precursor. The average chemical composition of the synthesized todorokites by refluxing for 8 h and for 2. h was Mg0.19MnO2.11(H2.)1.15 and in0.17-MnO2.10(H2.)0.88, respectively. The crystallinity of the todorokite increased and no other phase was produced with increasing refluxing period. The synthesized todorokites have the same morphologies and the similar structural characteristics with the natural todorokites and hydro-thermally synthesized samples. The chemical compositions of the synthetic tordorokites by refluxing process are close to those of todorokites synthesized by hydrothermal process, except a higher average oxidation state of Mn for the former.

关键词： todorokite,birnessite,manganese oxide,refluxing,hydrothermal,synthesis.

MCM-41 Prepared with Ionic Liquid and Cethytrimethylammonium Bromide as Co-templates

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Journal of wuhan university of Technology(Materials Science) 2009年第1期24卷 25-29页

作者：张光旭 School of Chemical Engineering Wuhan University of Technology College of Chemistry and Molecular sciences Wuhan University

The mesoporous molecular sieves MCM-41 were prepared using room tempera-ture ionic liquid （RTIL） synthesized in laboratory and cethytrimethylammonium bromide （CTAB） as compound templates for the first time. They were prepared under low aging temperature and short aging time. Via characterizing by XRD and nitrogen adsorption instrument, MCM-41 synthesized by this new method exhibited good crystal structure and narrow pore distribution. The following pre-paratory conditions was optimal： the molar ratio of RTIL to CTAB was 1.0∶1.0, aging at 80 ℃, for 40 h and calcined at 540 ℃. It is found that the acidified MCM-41 improves its activity as catalyst over the unmodified ones.

关键词： mesoporous molecular sieve hydrothermal crystallization co-templates ionicliquid MCM-41

Pathways of birnessite formation in alkali medium

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Science China Earth Sciences 2005年第9期48卷 1438-1451页

作者： FENG Xionghan1, TAN Wenfeng1, LIU Fan1, HUANG Qiaoyun1 & LIU Xiangwen2.1. College of Resources and Environment, Huazhong Agricultural university, wuhan 430070, China 2. Testing Center, China university of geosciences, wuhan 430074, China College of Resources and Environment Huazhong Agricultural University Wuhan China Testing Center China University of Geosciences Wuhan China

Birnessite is a common weathering and oxidation product of manganese-bearing rocks. An O2.oxidation procedure of Mn(OH)2.in the alkali medium has been used to synthesize birnessite. Fast and powder X-ray diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED), energy dispersed X-ray analysis (EDAX), infrared spectroscopy (IR) techniques and chemical composition analysis, Eh-pH equilibrium diagram approaches were employed to investigate the reaction process and pathways of birnessite formation. Results showed that the process of the birnessite formation could be divided into four stages: (1) forma- tion stage for hausmannite and feitknechtite, (2. stage of transformation of hausmannite and feitknechtite to buserite, (3) buserite crystal growing stage, and (4) stage of conversion of buser- ite into birnessite. Mn(OH)2.was mainly present as amorphous state only for a short initial time of oxidation reaction. In the oxidation process, buserite formed following two pathways by recrys- tallization after dissolution of the intermediates, and the transformations of the minerals de- pended on the Eh determined by the dissolved O2.concentration on their surfaces. The results are fundamental in further exploration on the mechanism of birnessite formation in the alkali medium. A great practical significance would also be expected with respect to the areas of mate- rial sciences.

关键词： birnessite, pathway of formation, reaction process, Eh-pH diagram, hausmannite, feitknechtite.

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Science China Earth Sciences 2004年第10期47卷 896-911页

作者： ZHANG Changhou1,2. WU Ganguo1,2. WANG Genhou2. ZHANG Weijie2.& SONG Honglin2.1. Key Laboratory of Lithospheric Tectonics and Lithoprobing Technology, China university of geosciences, Ministry of Education of China, Beijing 100083, China 2. School of Earth Sciences and Mineral Resources, China university of geosciences, Beijing 100083, China Key Laboratory of Lithospheric Tectonics and Lithoprobing Technology China University of Geosciences Ministry of Education of China Beijing China School of Earth Sciences and Mineral Resources China University of Geosciences Beijing China

The northwest trending tectonic belt in the middle part of the Mesozoic intraplate Yanshan Orogenic Belt, northeast Hebei Province, is composed of thrusts, extensional faults, strike-slip faults and syntectonic sedimentations as well. The northeastward basement-involved major thrusting deformation occurred between 174Ma and 168MaBP and was followed by an intrusion of the granitic plutonic rocks. As a part of the post-thrusting extensional deformations a northwest extending volcano-sedimentation system of Late Jurassic and Early Cretaceous formed in the southwest side of the belt. These volcano-sedimentary sequences are divided into Tuchengzi Formation, Zhangjiakou Formation, Yixian Formation and Jiufotang Formation re- spectively. They are characterized by southeastward migration as a result of the increasing down-dip slip displacement along the major extensional fault toward the southeast of the belt. The provenance area of the Jiufotang Formation north to it experienced southwestward thrusting during and after its later sedimentation. The thrusting in this stage resulted in the formation of an asymmetric footwall syncline with vergence to SW in the Jiufotang Formation in the NE side of the basin. Finally a dextral strike-slip deformation occurred along the NW tectonic belt. The striking tectono-geomorphological features and present seismic activities along this belt indicate that it has been being active since Cenozoic era and is still in the active state at present. This northwest extending tectonic belt was following the same direction and location as the existing fault systems within the basement as revealed by former geological and geophysical studies. So it is reasonable to infer the Mesozoic deformation along this belt to be a result of reactivation of the basement structures in a favorable tectonic stress field. The reactivation of basement struc- tures might be taken as one of the mechanisms of intraplate deformation and orogeny.

关键词： Yanshan Orogenic Belt, northwest extending tectonic complex, thrust system, geochronology.

2.19年超强台风“利奇马”外雨带降水精细结构分析

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中国海洋大学学报(自然科学版) 2024年

作者：彭成祥端义宏冯佳宁 1.复旦大学大气与海洋科学系/大气科学研究院 2.中国气象科学研究院灾害天气国家重点实验室复旦大学大气与海洋科学系/大气科学研究院中国气象科学研究院灾害天气国家重点实验室

本文利用中国地面高时空分辨率的降水资料,分析台风“利奇马”(Lekima)登陆期间,其外雨带在浙江沿海地区产生的降水特征。结果表明,“利奇马”外雨带影响下浙江地区降水过程的累计降水、分钟雨强均呈现显著极端性,强降水中心呈现带状分... 详细信息

本文利用中国地面高时空分辨率的降水资料,分析台风“利奇马”(Lekima)登陆期间,其外雨带在浙江沿海地区产生的降水特征。结果表明,“利奇马”外雨带影响下浙江地区降水过程的累计降水、分钟雨强均呈现显著极端性,强降水中心呈现带状分布特征,在空间和时间上具有明显的非均匀性。同时,本次降水呈现出多种时间尺度的波动特征,周期12.～192.min的波动信号贯穿了整个降水过程。外雨带主要位于台风移动方向前侧,其不同位置的降水波动特征有所不同,雨带外边缘降水小波功率谱有两个明显的大值中心,即除周期12.～192.min波动信号外,还有准周期16～64 min的波动特征;雨带内侧则分为周期12.～2.6 min的波动信号和多个周期在16 min以下的高频波动信号。本文的研究对提高登陆台风的降水精细化预测水平有重要意义。

关键词：台风利奇马降水时空演变波动特征

A simple lattice Boltzmann scheme for low Mach number reactive flows

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Science China(Technological Sciences) 2006年第6期49卷 714-726页

作者： CHEN Sheng1,2. LIU Zhaohui2. ZHANG Chao2. HE Zhu2. TIAN Zhiwei2. SHI Baochang 2.& ZHENG Chuguang2.1. Technology Center of wuhan Iron and Steel (Group) Company, wuhan 430080, China 2. State Key Laboratory of Coal Combustion, Hua Zhong{2. of Science and Technology, wuhan 430074, China State Key Laboratory of Coal Combustion Hua Zhong University of Science and Technology

For simulating low Mach number reactive flows, a simple and coupled lattice Boltzmann (CLB) scheme is proposed, by which the fluid density can bear significant changes. Different from the existing hybrid lattice Boltzmann (HLB) scheme and non-coupled lattice Boltzmann (NCLB) scheme, this scheme is strictly lattice Boltzmann style and the fluid density couples directly with the temperature. Because it has got rid of the constraint of traditional thought in lattice Boltzmann scheme,on the basis of the equality among the particle speed c, the time step △t and the lattice grid spacing △x held, both c and △t can be adjusted in this scheme according to a "characteristic temperature" instead of the local temperature. The whole algorithm becomes more stable and efficient besides inheriting the intrinsically outstanding strong points of conventional lattice Boltz-mann scheme. In this scheme, we also take into account different molecular weights of species, so it is more suitable for simulating actual low Mach number reactive flows than previous work. In this paper, we simulated a so-called "counter-flow" premixed propane-air flame, and the results got by our scheme are much better than that obtained by NCLB. And the more important thing is that the exploration in this work has offered a kind of brand-new train of thought for building other novel lattice Boltzmann scheme in the future.

关键词： lattice Boltzmann, low Mach number flows, reactive flows, simulation.

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高校学科质量与区域科技创新

世界经济 2024年 65-98页

作者：范剑勇张丰唐为 1.复旦大学世界经济研究所 2.复旦大学经济学院 3.上海财经大学公共经济与管理学院复旦大学世界经济研究所上海财经大学公共经济与管理学院复旦大学经济学院

Exploiting a large-scale relocation of university departments in the 1950s, this paper examines the impact of university subject quality on local innovation at the disciplinary level, using the net number of department relocation across cities as IV. We find that: 1) A 1% improvement of university subject rating increases the number of local patent applications and patent citations related to the subject by 0.6% and 1.2. respectively; 2. The impact of university subject quality on local innovation structure only exists in medium and high-tech industries, and is generally stronger in the central and western provinces; 3) Collaborated R&D between universities and firms, the citation of university patents by local social patents, and the improvement of specific human capital in the local labor market constitutes three important channels for the local spillover effect of the university subjects. The policy implications of this paper help shed light on how to facilitate innovation and high-quality development of the economy.

关键词：学科质量科技创新院系调整