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Coevolution of global brachiopod palaeobiogeography and tectonopalaeogeography during the Carboniferous

Journal of Palaeogeography 2021年第3期10卷 284-301页

作者： Ning Li cheng-wen wang Pu Zong Yong-Qin Mao College of Earth Sciences Jilin UniversityChangchun 130061Jilin ProvinceChina International Center of Future Science Dinosaur Evolution Research CenterJilin UniversityChangchun 130061Jilin ProvinceChina Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Guizhou Mountain Resources Research Institution Guiyang 550001Guizhou ProvinceChina

The global brachiopod palaeobiogeography of the Mississippian is divided into three realms, six regions, and eight provinces, while that of the Pennsylvanian is divided into three realms, six regions, and nine provinces. On this basis,we examined coevolutionary relationships between brachiopod palaeobiogeography and tectonopalaeogeography using a comparative approach spanning the Carboniferous. The appearance of the Boreal Realm in the Mississippian was closely related to movements of the northern plates into middle–high latitudes. From the Mississippian to the Pennsylvanian, the palaeobiogeography of Australia transitioned from the Tethys Realm to the Gondwana Realm,which is related to the southward movement of eastern Gondwana from middle to high southern latitudes. The transition of the Yukon–Pechora area from the Tethys Realm to the Boreal Realm was associated with the northward movement of Laurussia, whose northern margin entered middle–high northern latitudes then. The formation of the six palaeobiogeographic regions of Mississippian and Pennsylvanian brachiopods was directly related to "continental barriers", which resulted in the geographical isolation of each region. The barriers resulted from the configurations of Siberia, Gondwana, and Laurussia, which supported the Boreal, Tethys, and Gondwana realms, respectively. During the late Late Devonian–Early Mississippian, the Rheic seaway closed and North America(from Laurussia) joined with South America and Africa(from Gondwana), such that the function of "continental barriers" was strengthened and the differentiation of eastern and western regions of the Tethys Realm became more distinct. In the Barents Ocean tectonic domain during the Pennsylvanian, the brachiopods on the northern margin of the Barents Ocean formed the Verkhoyansk–Taymyr Province, while those on the southern margin formed the Yukon–Pechora Province. The Mongolia–Okhotsk Province was formed by brachiopods of the Mongolia–Okhotsk Ocean tectoni

关键词： Carboniferous Brachiopod Palaeobiogeography Tectonopalaeogeography Coevolution

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Microstructural evolution in electroformed nickel shaped-charge liners with nano-sized grains undergone deformation at ultrahigh strain rate

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 617-623页

作者： Feng Yang Chun-hua Li Sheng-wei cheng Lei wang wen-huai Tian School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Nickel shaped-charge liners with nano-sized grains were prepared by the electroforming technique, and the deformation at ultrahigh strain rate was performed by explosive detonation. The as-formed and post-deformed microstructures of electroformed nickel shaped-charge liners with nano-sized grains were observed by means of transmission electron microscopy, and the orientation distribution of the grains was analyzed by the electron backscattering pattern （EBSP） technique. The melting phenomenon in the jet fragment and the recovery and recrystallization in the slug after plastic deformation at ultrahigh-strain rate were observed in the ultrafine-grained nickel shaped-charge liners. The research evidence shows that dynamic recovery and recrystallization play an important role in plastic deformation at ultrahigh strain rate.

关键词： electroformed nickel nanosized plastic deformation electroformation microtexture dynamic recovery and recrystallization

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Design of Waveguide Integrated Ge-Quantum-Well Electro-Absorption Modulators

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Chinese Physics Letters 2011年第1期28卷 102-105页

作者： ZHAO Hong-Wei HU Wei-Xuan XUE Chun-Lai cheng Bu-wen wang Qi-Ming State Key Laboratory of Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing 100083

We present two designs for a waveguide Oe-quantum-well electro-absorption modulator. In our designs, the strip SOI waveguides are butt-coupled and evanescent-coupled to the modulator, respectively. The proposed Gequantum-weB electro-absorption modulator is based on quantum-confined Stark effect （QCSE）, having a 3-dB bandwidth above 50GHz, as well as a low switching power （around 60fJ/bit at 1435nm）. In the butt-coupled design, the optimized extinction ratio is up to 11.4 dB, while the insertion loss is only 6. 74 dB. For the second one, which utilizes evanescent coupling, the extinction ratio and insertion loss are 9.18 dB and 6. 72 dB, respectively.

关键词： Optics quantum optics and lasers

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Approximation Algorithms for Solving the 1-Line Minimum Steiner Tree of Line Segments Problem

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Journal of the Operations Research Society of China 2024年第3期12卷 729-755页

作者： Jian-Ping Li Su-Ding Liu Jun-Ran Lichen Peng-Xiang Pan wen-cheng wang Department of Mathematics Yunnan UniversityKunming650504YunnanChina School of Mathematics and Physics Beijing University of Chemical TechnologyBeijing650504China

We address the 1-line minimum Steiner tree of line segments(1L-MStT-LS)***,given a set S of n disjoint line segments in R^(2),we are asked to find the location of a line l and a set E_(l) of necessary line segments(i.e.,edges)such that a graph consisting of all line segments in S ∪ E_(l) plus this line l,denoted by T_(l)=(S,l,E_(l)),becomes a Steiner tree,the objective is to minimize total length of edges in E_(l) among all such Steiner ***,we are asked to find a set E_(0) of necessary edges such that a graph consisting of all line segments in S ∪ E_(0),denoted by T_(S)=(S,E_(0)),becomes a Steiner tree,the objective is to minimize total length of edges in E_(0) among all such Steiner trees,we refer to this new problem as the minimum Steiner tree of line segments(MStT-LS)*** addition,when two endpoints of each edge in Eo need to be located on two different line segments in S,respectively,we refer to that problem as the minimum spanning tree of line segments(MST-LS)*** obtain three main results:(1)Using technique of Voronoi diagram of line segments,we design an exact algorithm in time O(n log n)to solve the MST-LS problem;(2)we show that the algorithm designed in(1)is a 1.214-approximation algorithm to solve the MStT-LS problem;(3)using the combination of the algorithm designed in(1)as a subroutine for many times,a technique of finding linear facility location and a key lemma proved by techniques of computational geometry,we present a 1.214-approximation algorithm in time O(n^(3) log n)to solve the 1L-MStT-LS problem.

关键词： 1-Line minimum Steiner tree of line segments Minimum spanning tree of line segments Voronoi diagram of line segments Steiner ratio Approximation algorithms

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Expression of Eph-Ephrin A Molecules in Endometrium During Swine Embryo Implantation Examined Using Real-Time RT-PCR

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Agricultural Sciences in China 2011年第9期10卷 1445-1451页

作者： FU Yan-feng FU Jin-luan YANG Lu TIAN Ming-ming CHEN wen-cheng wang Ai-guo College of Animal Science and Technology China Agricultural University/Key Laboratory of Animal Genetics and Breeding Ministry of Agriculture Beijing 100193 P.R. China

Erythropoietin-producing hepatocellular receptor and its membrane-bound ligands （Eph-Ephrin） system could regulate some mammalian blastocyst attachment and spreading. In order to investigate the involvement of the Eph-Ephrin system in swine embryo attachment, mRNA expression of Eph-Ephrin molecules in endometrium was examined by real-time RT- PCR during embryo implantation in pigs. The results indicated that mRNA expressions of Eph A5, A7 and Ephrin A5 all continually increased from pregnancy day 13 to 24. Ephrin A3 mRNA expression significantly increased from day 13 to 18 and decreased from day 18 to 24, and the expression was the lowest on pregnancy day l 3 and the highest on day 18. However, Ephrin A4 mRNA expression was the lowest on pregnancy day 18 and the highest on day 24, and the expression decreased from day 13 to 18 and increased from day 18 to 24. Furthermore, mRNA expressions of Eph A5 and A7 were both found in other tissues, such as brain, muscle, intestine, stomach, etc. These findings suggest that the Eph-Ephrin system may play an important role in regulating the contact between blastocysts and endometrium during swine embryo implantation.

关键词： Eph-Ephrin real-time RT-PCR endometrium implantation pig

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THE FLOW PATTERNS OF BUBBLE PLUME IN AN MBBR

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Journal of Hydrodynamics 2011年第4期23卷 510-515页

作者： LI Shi-rong cheng wen wang Meng CHEN Chen Key Laboratory of Northwest Water Resources and Environmental Ecology of Ministry of Education Xi＇an University of Technology Xi＇an 710048 China Oil Production Plant of No. 4 Changqing Oilfield Company China National Petroleum Corporation Jing Bian 718500 China

The flow patterns of the gas-liquid two-phase flow in a Moving-Bed Biofilm Reactor （MBBR） have a critical effect upon the mass transfer by the convection. Bubble plumes promote unsteadily fluctuating two-phase flows during the aeration. This article studies the unsteady structure of bubble plumes through experiments. The time-serial bubble plume images in various cases of the tank are analyzed. The Recursive Cross Correlation-Particle Image Velocimetry （RCC-PIV） is used to calculate the velocities in those cases, and then the time-serial vortex, the total turbulence intensity, the time-serial streamline are obtained. It is shown that the aspect ratio and the void fraction are the dominant factors influencing the unsteady structure of bubble plumes. When the aspect ratio is unity and the void fraction is high, the bubble plumes see a symmetrical vortex structure with a long residence time, which is beneficial for optimizing the aeration system and enhancing the applied range of bubble plumes.

关键词： bubble plume Recursive Cross Correlation (RCC) Particle Image Velocimetry (PIV) flow pattern

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On Some Proximity Problems of Colored Sets

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Journal of Computer Science & Technology 2014年第5期29卷 879-886页

作者：范成林罗军王文成钟发荣朱滨海 Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Huawei Noah's Ark Laboratory State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences College of Mathematics Physics and Information Technology Zhejiang Normal University Department of Computer Science Montana State UniversityBozeman MT 59717 U.S.A. MemberACM

The maximum diameter color-spanning set problem（MaxDCS） is defined as follows： given n points with m colors, select m points with m distinct colors such that the diameter of the set of chosen points is maximized. In this paper, we design an optimal O（n log n） time algorithm using rotating calipers for MaxDCS in the plane. Our algorithm can also be used to solve the maximum diameter problem of imprecise points modeled as polygons. We also give an optimal algorithm for the all farthest foreign neighbor problem（AFFN） in the plane, and propose algorithms to answer the farthest foreign neighbor query（FFNQ） of colored sets in two- and three-dimensional space. Furthermore, we study the problem of computing the closest pair of color-spanning set（CPCS） in d-dimensional space, and remove the log m factor in the best known time bound if d is a constant.

关键词： computational geometry colored set algorithm maximum diameter color-spanning set problem

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Moment Redistribution Effect of the Continuous Glass Fiber Reinforced Polymer-Concrete Composite Slabs Based on Static Loading Experiment

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Structural Durability & Health Monitoring 2025年第1期19卷 105-123页

作者： Zhao-Jun Zhang wen-Wei wang Jing-Shui Zhen Bo-cheng Li De-cheng Cai Yang-Yang Du Hui Huang Offshore Oil Engineering Co.Ltd. Tianjin300461China Department of Bridge Engineering School of TransportationSoutheast UniversityNanjing211189China

This study aimed to investigate the moment redistribution in continuous glass fiber reinforced polymer(GFRP)-concrete composite slabs caused by concrete cracking and steel bar yielding in the negative bending moment *** experimental bending moment redistribution test was conducted on continuous GFRP-concrete composite slabs,and a calculation method based on the conjugate beam method was *** composite slabs were formed by combining GFRP profiles with a concrete layer and supported on steel beams to create two-span continuous composite slab *** methods,epoxy resin bonding,and stud connection,were used to connect the composite slabs with the steel *** experimental findings showed that the specimen connected with epoxy resin exhibited two moments redistribution phenomena during the loading process:concrete cracking and steel bar yielding at the internal *** contrast,the composite slab connected with steel beams by studs exhibited only one-moment redistribution phenomenon throughout the loading *** the concrete at the internal support cracked,the bending moment decreased in the internal support section and increased in the midspan *** the steel bars yielded,the bending moment further decreased in the internal support section and increased in the mid-span *** GFRP profiles do not experience cracking,there was no significant decrease in the bending moment of the mid-span *** test specimens experienced compressive failure of concrete at the mid-span *** results showed good agreement between the calculated and experimental values of bending moments in the mid-span section and internal support *** proposed model can effectively predict the moment redistribution behavior of continuous GFRP-concrete composite slabs.

关键词： Moment redistribution GFRP-concrete composite slabs bending moment experimental study analysis model

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Paraspinal approach for thoracolumbar fracture

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Chinese Journal of Traumatology 2011年第1期14卷 3-6页

作者： JIANG Rui WU Han wang Jin-cheng LI wen-xuan wang Yang Department of Orthopedics China-Japan Union Hospital Jilin University Changchun 130033 China

Objective： To explore the advantages and indications of the paraspinal approach by anatomical study and clinical ***： The anatomical data and clinical practice of 27 cases were analyzed to explore the accurate approach between the paraspinal muscles and the structure of ambient tissues, as well as the results of clinical application of paraspinal approach. The operation time, blood loss, incision length, radiographic result （Cobb angle, height of anterior edge of the vertebrae） were compared with those in 24cases treated by traditional ***： Complete exposure of the facets could be easily performed by identifying natural cleavage plane between the multifidus and Iongissimus muscles. The natural muscular cleavage was （1.47±0.23） cm lateral to the midline for females, and （1.64±0.35） cm for males at T12 level. The distance was （3.3±0.6） cm lateral to the midline for females,and （3.7±1.0） cm for males at L4 level. In paraspinal approach group, the operation time was （76.2±15.7） min, blood loss was （91.6±16.9） ml and incision length was （7.6±0.8） cm. In traditional approach group, the operation time was （121.4±19.6） min, blood loss was （218.7±32.3 ） ml and incision length was （17.4±2.1） cm. To compare paraspinal approach with traditional approach, the operation time, blood loss and incision length had statistical difference （P〈0.05） and the radiographic result （Cobb angle, height of anterior edge of the vertebrae） had no statistical difference （P〉0.05）.Conclusions： When the paraspinal approach is performed through natural cleavage plane between the multifidus and longissimus muscles, there are no wide muscular disinsertions, leaving the supraspinous and interspinous ligaments intact. The distance of natural cleavage to the midline is different at T12 and L4 planes. By this approach,the facet joints can be explored easily and completely, and a clear surgical field will be available for the placement of pedicle screws. As a minimally invasive a

关键词： Fractures,bone Lumbar vertebrae Thoracic vertebrae Surgical procedures,operative

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Effcet of Laurencia extract combined with vitamin E in prevention of radiation

Effcet of Laurencia extract combined with vitamin E in preve...

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第十二届全国营养科学大会

作者： LIANG Hui Ying LIU Qing wang wen-cheng wang Ai-guo MA Department of Nutrition Medical CollegeQingdao University Laboratory of Celluar and Molecular Biology Medical CollegeQingdao University

ObjectivesT o observe the protective effect of Laurencia extrac(LET)&Vitamin E(VE)in sub-acute radiated *** ixty male Kunming mice were randomly assigned to six groups(n=10):control group,radiationmodel group,LET+ET l...

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