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Establishment of extensively drug-resistant Pseudomonas aeruginosa pneumonia model in rat
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作者 AN Ran LIU Feng-yun +8 位作者 ZHAO Qi-liang CAI Wen-xin SUN Hong-yuan CHEN Ming-hu CHANG Li YIN Yan-zhong LIU Kai ZHANG Hui-qi LIU Min 《Journal of Hainan Medical University》 CAS 2023年第15期7-13,共7页
Objective:To establish extensively drug-resistant Pseudomonas aeruginosa(XDR-PA)infection-induced pneumonia model in rats.Methods:Twenty-four male SD rats were randomly divided into blank group,low bacterial group,med... Objective:To establish extensively drug-resistant Pseudomonas aeruginosa(XDR-PA)infection-induced pneumonia model in rats.Methods:Twenty-four male SD rats were randomly divided into blank group,low bacterial group,medium bacterial group,and high bacterial group.The low,medium and high bacterial groups were given intratracheal instillation of 0.1 mL of bacterial suspension(bacterial concentration in turn is 7.5×10^(9),3×10^(10),6×10^(10)CFU/mL),while the blank group were given the same volume of sterile normal saline.After modeling,the general conditions of rats in each group were observed,including mental state,hair,respiration,activity,eating,weight,and the survival curve was drawn.The pathological characteristics of lung tissue and the infiltration of inflammatory cells were observed.Pathogenic identification of each group was carried out by bacterial culture of lung tissue homogenate.Results:The general state of the blank group was normal,and the rats in other groups showed signs of mental depression,bristling,shortness of breath,even oral and nasal bleeding,decreased food intake and activity,and significant weight loss,and different degrees of death within 48 hours,the difference was statistically significant(P<0.05).Pathological results showed that the alveolar structure of rats in the blank group was complete,and the alveolar space was clear without exudation.The lung tissue of the low and medium bacterial groups showed obvious inflammatory cell infiltration,alveolar structure destruction,alveolar septum thickening,interstitial edema,but the pathological damage of the medium group was more severe,with a mortality rate of up to 50%,and the mortality rate of the low bacterial group was 17%.In the high bacterial group,red blood cells,inflammatory cells and a large amount of fibrin-like exudation can be seen in the alveolar space,which has the pathological characteristics of acute respiratory failure,and the mortality rate is as high as 67%.The results of bacterial culture of lung tissue homogenate showed that the blank group had no bacterial colonies,while PA colony growth can be seen in low,medium and high bacterial groups.Conclusion:9 Intratracheal instillation of low bacterial count(0.1 mL of 7.5×10^(9) CFU/mL)XDR-PA bacterial suspension can successfully construct a rat pneumonia model of XDR-PA infection. 展开更多
关键词 extensively drug-resistant Pseudomonas aeruginosa PNEUMONIA Animal model RAT
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Cenozoic tectono-sedimentary characteristics and extension model of the Northwest Sub-basin,South China Sea 被引量:8
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作者 Weiwei Ding Mingbi Li +2 位作者 Lihong Zhao Aiguo Ruan Zhenli Wu 《Geoscience Frontiers》 SCIE CAS 2011年第4期509-517,共9页
Based on the interpretations of three seismic profiles and one wide-angle seismic profile across the Northwest Sub-basin,South China Sea.stratigraphic sequences,deformation characteristics and an extension model for t... Based on the interpretations of three seismic profiles and one wide-angle seismic profile across the Northwest Sub-basin,South China Sea.stratigraphic sequences,deformation characteristics and an extension model for this sub-basin have been worked out.Three tectonic-stratigraphic units are determined.Detailed analyses of extension show that the event occurred mainly during the Paleogene and resulted in the formation of half-grabens or grabens distributed symmetrically around the spreading center.Sediments are characterized by chaotic and discontinuous reflectors,indicating clastic sediments. Farther to the southwest,the sub-basin features mainly continental rifting instead of sea-floor spreading. The rifting would have been controlled by the shape of the massif and developed just along the northern edge of the Zhongsha-Xisha Block,rather than joined the Xisha Trough.After 25 Ma.a southward ridge jump triggered the opening of the Southwest Sub-basin.The NW-directed stress caused by the sea-floor spreading of the Northwest Sub-basin may have prevented the continuous opening of the sub-basin.After that the Northwest Sub-basin experienced thermal cooling and exhibited broad subsidence.The deep crustal structure shown by the velocity model from a wide-angle seismic profile is also symmetrical around the spreading center,which indicates that the Northwest Sub-basin might have opened in a pure shear model. 展开更多
关键词 Continental rifting CENOZOIC Tectono-sedimentary characteristics extension model Northwest Sub-basin Marginal sea
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MECHANICAL PRODUCT EXTENSIVE INTELLIGENT CONCEPTUAL DESIGN 被引量:2
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作者 ZhangGuoquan ZhongYifang ZhangWeiguo 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第1期1-5,共5页
Based on extenics, an extensive functional information model(function-behavioral action-structure-environmental constraint) of the mechanical productintelligent conceptual design is developed, and the mechanism of the... Based on extenics, an extensive functional information model(function-behavioral action-structure-environmental constraint) of the mechanical productintelligent conceptual design is developed, and the mechanism of theoretic structure solutions isproduced, the mapping relations between function-behavior and behavior-structure are analyzed. Themodel is applied to the filling material system's conceptual design to verify validity. 展开更多
关键词 EXTENICS extensive intelligent conceptual design extensive model
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Extension Modeling Strategy of Intelligent Detection in D.huoshanense Photosynthesis Process 被引量:4
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作者 Rongde Lu Can Qin Yunsheng Bao 《Intelligent Control and Automation》 2011年第2期126-132,共7页
Aiming at the limitations of the existing knowledge representations in intelligent detection, a new method of Extension-based Knowledge Representation (EKR) was proposed. The definitions, grammar rules, and storage st... Aiming at the limitations of the existing knowledge representations in intelligent detection, a new method of Extension-based Knowledge Representation (EKR) was proposed. The definitions, grammar rules, and storage structure of EKR were presented. An Extension Solving Model (ESM) based on EKR was discussed in detail, including creation of the extension constraint graph, extended inference, calculation of relevant functions and generation of extension set. A knowledge base system based on EKR and ESM was developed, which was applied in extension repository system intelligent design of detection in photosynthesis process of D.huoshanense. More reasonable results were obtained than traditional rule-based system. EKR was feasible in intelligent design to solve the problem of intelligent detection knowledge representations. 展开更多
关键词 extension-Based KNOWLEDGE Representation (EKR) Intelligent Detection extensION modeling STRATEGY (EMS) PHOTOSYNTHESIS Process of D.huoshanense (PPDH)
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EXTENSION OF SEQUENCE STRATIGRAPHIC MODELAND SEQUENCE STRATIGRAPHIC ANALYSIS IN LIMNIC DEPOSITIONAL BASIN 被引量:1
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作者 李增学 魏久传 +4 位作者 王民镇 李守春 李青山 金秀昆 兰恒星 《Journal of Coal Science & Engineering(China)》 1996年第2期1-8,共8页
The architectural patterns of sedimentary succession are diverse in different depositionalbasins. The sedimentary architecture and geological condition of such basins asepicontinental sea, intraplate limnic basins, et... The architectural patterns of sedimentary succession are diverse in different depositionalbasins. The sedimentary architecture and geological condition of such basins asepicontinental sea, intraplate limnic basins, etc., differ cIearly from those of continentalmargin basin. Extension, complement and perfection of sequence stratigraphic models are needed in the studies of various depositional basins based on the classical sequence model. This paper, for this reason,expounds the thought, principles of sequence division, methodology and technology of the study of sequence stratigraphy in epicontinental and limnic basins. 展开更多
关键词 epicontinental sea basin limnic basin extension of sedimentary sequence model sequence stratigraphic analysis
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Effect Analysis of Gurson Model Parameters on Crack Extension of Pipeline
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作者 Tieping Li Xinlu Tian 《Journal of Applied Mathematics and Physics》 2013年第6期54-56,共3页
Leakage-before-break technique is widely used in high energy pipeline of nuclear plant, for which crack stability of pipeline under complex loading condition is a key issue, and crack growth resistance curve of pipeli... Leakage-before-break technique is widely used in high energy pipeline of nuclear plant, for which crack stability of pipeline under complex loading condition is a key issue, and crack growth resistance curve of pipeline material is the important foundation for crack stability analysis. In this paper, ferritic steel A533B is studied, Gurson damage model is used to simulate crack process of contact tension specimen under unitension, and effect of Gurson model parameter on simulation result is discussed. The following results are found during simulation: initial porosity factor is the main parameter, when it increases gradually, unstable crack extension will be observed;however, only initial J toughness is affected by critical porosity factor;the minor parameter is load step control, when it increases, stable and convergent result is obtained. All results in this paper can be used to determine parameters in Gurson mode, which will be foundation for crack extension analysis of pipeline. 展开更多
关键词 Leakage-Before-Break CRACK Growth Resistance CURVE Gurson Damage model CRACK extension
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Two-Dimensional Lithium-Ion Battery Modeling with Electrolyte and Cathode Extensions
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作者 Glyn F. Kennell Richard W. Evitts 《Advances in Chemical Engineering and Science》 2012年第4期423-434,共12页
A two-dimensional model for transport and the coupled electric field is applied to simulate a charging lithium-ion cell and investigate the effects of lithium concentration gradients within electrodes on cell performa... A two-dimensional model for transport and the coupled electric field is applied to simulate a charging lithium-ion cell and investigate the effects of lithium concentration gradients within electrodes on cell performance. The lithium concentration gradients within electrodes are affected by the cell geometry. Two different geometries are investigated: extending the length of the electrolyte past the edges of the electrodes and extending the length of the cathode past the edge of the anode. It is found that the electrolyte extension has little impact on the behavior of the electrodes, although it does increase the effective conductivity of the electrolyte in the edge region. However, the extension of the cathode past the edge of the anode, and the possibility for electrochemical reactions on the flooded electrode edges, are both found to impact the concentration gradients of lithium in electrodes and the current distribution within the electrolyte during charging. It is found that concentration gradients of lithium within electrodes may have stronger impacts on electrolytic current distributions, depending on the level of completeness of cell charge. This is because very different gradients of electric potential are expected from similar electrode gradients of lithium concentrations at different levels of cell charge, especially for the LixC6 cathode investigated in this study. This leads to the prediction of significant electric potential gradients along the electrolyte length during early cell charging, and a reduced risk of lithium deposition on the cathode edge during later cell charging, as seen experimentally by others. 展开更多
关键词 LITHIUM-ION Cell Mathematical modeling CATHODE extensION ELECTROLYTE extensION Current DISTRIBUTIONS Electric and Concentration Fields
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NUMERICAL MODELLING OF LITHOSPHERE EVOLUTION IN THE NORTH CHINA CRATON: THERMAL THINNING VERSUS TECTONIC EXTENSION THINNING
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作者 ZHANG Yan hua 1,2 , LIN Ge 2, WANG Yue jun 2 and FAN Wei ming 2 (1. CSIRO Exploration & Mining, P.O. Box 437, Nedlands, WA 6009, Australia 2. Changsha Institute of Geotectonics, Chinese Academy of Sciences, Changsha 410013, China) 《Geotectonica et Metallogenia》 2001年第1期72-74,共3页
The boundary between lithosphere and asthenosphere essentially represents a thermal boundary (the solidus). Temperature variation across this boundary can lead to the change of lithosphere thickness. In the case of el... The boundary between lithosphere and asthenosphere essentially represents a thermal boundary (the solidus). Temperature variation across this boundary can lead to the change of lithosphere thickness. In the case of elevated temperatures in a lithospheric layer above 1 200℃, partial melting will begin and the result of that is a thinned lithosphere. The other mechanism that can also thin lithosphere is extension. Stretching during an extension event can result in a thinner and longer lithosphere. The two mechanisms above are the reason why we can alserve large variations in lithosphere thickness spatially across various continents and temporally throughout the geological history. 展开更多
关键词 NUMERICAL modelLING OF LITHOSPHERE EVOLUTION IN THE NORTH CHINA CRATON THERMAL THINNING VERSUS TECTONIC extensION THINNING
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Estimation of Displacement and Extension due to Reverse Drag of Normal Faults: Forward Method
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作者 Shunshan Xu Angel Francisco Nieto-Samaniego +1 位作者 Huilong Xu Susana Alicia Alaniz-Álvarez 《International Journal of Geosciences》 CAS 2024年第1期25-39,共15页
In the case of reverse drag of normal faulting, the displacement and horizontal extension are determined based on the established equations for the three mechanisms: rigid body, vertical shear and inclined shear. Ther... In the case of reverse drag of normal faulting, the displacement and horizontal extension are determined based on the established equations for the three mechanisms: rigid body, vertical shear and inclined shear. There are three sub-cases of basal detachment for the rigid body model: horizontal detachment, antithetic detachment and synthetic detachment. For the rigid body model, the established equations indicate that the total displacement on the synthetic base (D<sub>t2</sub>) is the largest, that on the horizontal base (D<sub>t1</sub>) is moderate, and that on the antithetic base (D<sub>t3</sub>) is the smallest. On the other hand, the value of (D<sub>t1</sub>) is larger than the displacement for the vertical shear (D<sub>t4</sub>). The value of (D<sub>t1</sub>) is larger than or less than the displacement for the inclined shear (D<sub>t5</sub>) depending on the original fault dip δ<sub>0</sub>, bedding angle θ, and the angle of shear direction β. For all original parameters, the value of D<sub>t5</sub> is less than the value of D<sub>t4</sub>. Also, by comparing three rotation mechanisms, we find that the inclined shear produces largest extension, the rigid body model with horizontal detachment produces the smallest extension, and the vertical shear model produces moderate extension. 展开更多
关键词 Fault Rotation Fault Drag Fault Displacement extensION Forward model
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Calculation of the Standard Model Parameters and Particles Based on a SU(4) Preon Model
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作者 Jan Helm 《Journal of Modern Physics》 2024年第1期64-124,共61页
This paper describes an extension and a new foundation of the Standard Model of particle physics based on a SU(4)-force called hyper-color, and on preon subparticles. The hyper-color force is a generalization of the S... This paper describes an extension and a new foundation of the Standard Model of particle physics based on a SU(4)-force called hyper-color, and on preon subparticles. The hyper-color force is a generalization of the SU(2)-based weak interaction and the SU(1)-based right-chiral self-interaction, in which the W-and the Z-bosons are Yukawa residual-field-carriers of the hyper-color force, in the same sense as the pions are the residual-field-carriers of the color SU(3) interaction. Using the method of numerical minimization of the SU(4)-action based on this model, the masses and the inner structure of leptons, quarks and weak bosons are calculated: the mass results are very close to the experimental values. We calculate also precisely the value of the Cabibbo angle, so the mixing matrices of the Standard model, CKM matrix for quarks and PMNS matrix for neutrinos can also be calculated. In total, we reduce the 29 parameters of the Standard Model to a total of 7 parameters. 展开更多
关键词 SU(4) Generalization of Weak Interaction extension of Standard model Numerical Minimization of Action Hyper-Color Preon
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The Effects of Infrastructure Projects on House Prices and Rents:Evidence from the HS2 Extension Cancellation in the UK
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作者 Wentao Zhu 《Journal of Sustainable Business and Economics》 2024年第2期76-94,共19页
This paper uses the HS2 extension cancellation in November 2021 as a quasi-experiment to study its impact on house prices and rents in Leeds.Using a DiD approach on repeat sales and monthly rents,I compare property va... This paper uses the HS2 extension cancellation in November 2021 as a quasi-experiment to study its impact on house prices and rents in Leeds.Using a DiD approach on repeat sales and monthly rents,I compare property values near the HS2 station and proposed construction site before and after the announcement.Results show a 3.6%decrease in house prices and a 3.9%decline in rents near the station,while properties near the construction site experienced a 2.4%increase in prices and a 2.1%rise in rents.This is the first paper to analyse the HS2 cancellation effect using panel data methods. 展开更多
关键词 HS2 extension cancellation Externalities House price effects Transport infrastructure Difference-in-Differences model
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SWAT和WetSpa Extension在罗玉沟流域的应用比较 被引量:2
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作者 韩旖旎 牛健植 张由松 《水资源与水工程学报》 2014年第3期133-137,共5页
近年来,运用水文模型来研究流域水文状况越来越普遍,本文以黄土高原丘陵沟壑区第三副区的典型小流域为例,基于SWAT和WetSpa Extension两个模型,从模型的输入数据、模型的参数和模型模拟结果等方面进行比较,以期为该区水沙模拟选择合适... 近年来,运用水文模型来研究流域水文状况越来越普遍,本文以黄土高原丘陵沟壑区第三副区的典型小流域为例,基于SWAT和WetSpa Extension两个模型,从模型的输入数据、模型的参数和模型模拟结果等方面进行比较,以期为该区水沙模拟选择合适水文模型并为将来模型性能的改进提供参考。连续15年的校准验证表明:两个模型都能得到较好的结果,而SWAT模型能应用于水文及泥沙等模拟过程,相对来说功能更全面;WetSpa Extension模型目前仅能提供水文模拟的模块,优点在于模拟时间步长较任意,可进行洪水模拟。 展开更多
关键词 SWAT模型 WetSpa extension模型 分布式模型 罗玉沟流域 水文模拟
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角色建模工具RModeler的设计与实现
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作者 文斌 毛晓光 《计算机应用研究》 CSCD 北大核心 2008年第4期1257-1260,共4页
提倡在对象技术中基于角色识别对象及其协调关系,然后展开到类模型、接口模型、实体模型,同时对角色模型的形式化定义和表示方法进行了系统地研究,并在此基础上设计和实现了基于RML的可视化角色建模工具RModeler。RModeler目前完成了代... 提倡在对象技术中基于角色识别对象及其协调关系,然后展开到类模型、接口模型、实体模型,同时对角色模型的形式化定义和表示方法进行了系统地研究,并在此基础上设计和实现了基于RML的可视化角色建模工具RModeler。RModeler目前完成了代码实现和测试工作,并在实际开发中使用,运行良好。RModeler支持业务过程中采用RML语言的建模,具备将RML模型转换为UML模型的功能,采用业界标准数据描述格式XMI来传递和共享建模信息。 展开更多
关键词 角色 角色模型 角色建模语言 软件工具 扩展元数据交换
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Interaction between Downslope and Alongslope Processes on the Margins of Daihai Lake,North China:Implication for Deltaic Sedimentation Models of Lacustrine Rift Basin 被引量:12
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作者 YU Xinghe LI Shunli +3 位作者 CHEN Bintao TAN Chengpeng XIE Jing HU Xiaonong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第4期932-948,共17页
Daihai Lake, a modern lacustrine rift basin, located in Inner Mongolia, North China, serves as an important modern analog for understanding deltaic depositional processes in an active rift setting. Two of the deltas ... Daihai Lake, a modern lacustrine rift basin, located in Inner Mongolia, North China, serves as an important modern analog for understanding deltaic depositional processes in an active rift setting. Two of the deltas (Yuanzigou delta and Bulianghe delta) on the margins of Daihai Lake were surveyed to compare and contrast stacking patterns using aerial photographs, field trenching and sediment sampling. Shallow cores and trench data collected from the margins of Daihai Lake indicate that a variety of depositional processes have been active since Daihai Lake formed. Two 3-D sedimentation models which employ chronostratigraphic correlation technique were generated. The chronostratigraphic sedimentation models predict and represent the architectures and sand-body continuity of sediments. Stratigraphical coincidence of the broad sheeted drifts and channel erosion suggests a coupling between downslope and alongslope processes. Distributary mouth bars are prevalent in the front of deltas on steeper slopes due to the dominance of down-slope flows. On the contrary, the along-slope currents favor the development of distal bar deposits with sheeted sandbodies on gentle depositional slopes. This study provides an insight into the architecture of complex sedimentary facies associated with highlighting key differences between downslope flows and alongslope currents. The distribution of sand within these deltas is of particular interests, with applications in understanding the architecture of hydrocarbon reservoirs formed in lacustrine rift basin. 展开更多
关键词 downslope flows alongslope currents architectural element spatial extension model Daihai Lake
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Mesoscale SST perturbation-induced impacts on climatological precipitation in the Kuroshio-Oyashio extension region,as revealed by the WRF simulations 被引量:3
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作者 GAO Jiaxiang ZHANG Rong-Hua WANG Hongna 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第2期385-397,共13页
Mesoscale coupling between perturbations of mesoscale sea surface temperature (SST) and lowlevel winds has been extensively studied using available high-resolution satellite observations. However, the climatological i... Mesoscale coupling between perturbations of mesoscale sea surface temperature (SST) and lowlevel winds has been extensively studied using available high-resolution satellite observations. However, the climatological impacts of mesoscale SST perturbations (SST meso ) on the free atmosphere have not been fully understood. In this study, the rectified eff ect of SSTmeso on local climatological precipitation in the Kuroshio- Oyashio Extension (KOE) region is investigated using the Weather Research and Forecasting (WRF) Model;two runs are performed, one forced by low-resolution SST fields (almost no mesoscale signals) and another by additional high-resolution SSTmeso fields extracted from satellite observations. Climatological precipitation response to SST meso is characterized mainly by enhanced precipitation on the warmer flank of three oceanic SST fronts in this region. The results show that the positive correlation between the 10-m wind speed perturbations and SSTmeso is well captured by the WRF model with a reasonable spatial pattern but relatively weak strength. The addition of SSTmeso improves the climatological precipitation simulated by WRF with a better representation of fine-scale structures compared with satellite observations. A closer examination on the underlying mechanism suggests that while the pressure adjustment mechanism can explain the climatological precipitation enhancement along the fronts and the relatively high contribution of the convective precipitation, other factors such as synoptic events should also be taken into consideration to account for the seasonality of the precipitation response. 展开更多
关键词 MESOSCALE SST perturbations and eff ects WRF model Kuroshio-Oyashio extensION climatological PRECIPITATION
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AN APPLICATION OF EXTENSION THEORY TO THE EVALUATION OF SLOPE STABILITY 被引量:4
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作者 LIU Muyu Wuhan University of Technology 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1999年第4期57-62,共6页
The slope stability is affected by multiple factors. Thecomprehensive evaluation of the slope stability is a complicateproblem. The principles of extension theory have been used in thispaper to establish the matter-el... The slope stability is affected by multiple factors. Thecomprehensive evaluation of the slope stability is a complicateproblem. The principles of extension theory have been used in thispaper to establish the matter-element model for the evaluation ofslope stability. The quantitative evaluated results have been giventhrough the calculation of the matter-element dependent degree. 展开更多
关键词 extension theory matter-element model slope stability
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Optimal Precursors Triggering the Kuroshio Extension State Transition Obtained by the Conditional Nonlinear Optimal Perturbation Approach 被引量:3
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作者 Xing ZHANG Mu MU +1 位作者 Qiang WANG Stefano PIERINI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第6期685-699,共15页
In this study, the initial perturbations that are the easiest to trigger the Kuroshio Extension (KE) transition connecting a basic weak jet state and a strong, fairly stable meandering state, are investigated using ... In this study, the initial perturbations that are the easiest to trigger the Kuroshio Extension (KE) transition connecting a basic weak jet state and a strong, fairly stable meandering state, are investigated using a reduced-gravity shallow water ocean model and the CNOP (Conditional Nonlinear Optimal Perturbation) approach. This kind of initial perturbation is called an optimal precursor (OPR). The spatial structures and evolutionary processes of the OPRs are analyzed in detail. The results show that most of the OPRs are in the form of negative sea surface height (SSH) anomalies mainly located in a narrow band region south of the KE jet, in basic agreement with altimetric observations. These negative SSH anomalies reduce the merid- ional SSH gradient within the KE, thus weakening the strength of the jet. The KE jet then becomes more convoluted, with a high-frequency and large-amplitude variability corresponding to a high eddy kinetic energy level; this gradually strengthens the KE jet through an inverse energy cascade. Eventually, the KE reaches a high-energy state characterized by two well defined and fairly stable anticyclonic meanders. Moreover, sensitivity experiments indicate that the spatial structures of the OPRs are not sensitive to the model parameters and to the optimization times used in the analysis. 展开更多
关键词 Kuroshio extension states transition CNOP approach optimal precursor ocean modeling
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XML-based integration data model and schema mappingin multidatabase systems 被引量:5
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作者 LiRuixuan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第2期437-444,共8页
Multidatabase systems are designed to achieve schema integration and data interoperation among distributed and heterogeneous database systems. But data model heterogeneity and schema heterogeneity make this a challeng... Multidatabase systems are designed to achieve schema integration and data interoperation among distributed and heterogeneous database systems. But data model heterogeneity and schema heterogeneity make this a challenging task. A multidatabase common data model is firstly introduced based on XML, named XML-based Integration Data Model (XIDM), which is suitable for integrating different types of schemas. Then an approach of schema mappings based on XIDM in multidatabase systems has been presented. The mappings include global mappings, dealing with horizontal and vertical partitioning between global schemas and export schemas, and local mappings, processing the transformation between export schemas and local schemas. Finally, the illustration and implementation of schema mappings in a multidatabase prototype - Panorama system are also discussed. The implementation results demonstrate that the XIDM is an efficient model for managing multiple heterogeneous data sources and the approaches of schema mapping based on XIDM behave very well when integrating relational, object-oriented database systems and other file systems. 展开更多
关键词 multidatabase systems common data model schema mapping extensible markup language (XML).
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Photochemical Process Modeling and Analysis of Ozone Generation 被引量:5
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作者 王冰 邱彤 陈丙珍 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第6期721-729,共9页
Air pollution in modern city and industrial zones has become a serious public concern in recent years in China. Significance of air quality assessment and emission control strategy design is increasing. Most studies i... Air pollution in modern city and industrial zones has become a serious public concern in recent years in China. Significance of air quality assessment and emission control strategy design is increasing. Most studies in China focus on particulate matter(PM), especially PM2.5, while few account for photochemical secondary air pollutions represented by ozone(O3). In this paper, a procedure for air quality simulation with comprehensive air quality model with extensions(CAMx) is demonstrated for studying the photochemical process and ozone generation in the troposphere. As a case study, the CAMx photochemical grid model is used to model ozone over southern part of Beijing city in winter, 2011. The input parameters to CAMx include emission sources, meteorology field data, terrain definition, photolysis status, initial and boundary conditions. The simulation results are verified by theoretical analysis of the ozone generation tendency. The simulated variation tendency of domain-wide average value of hourly ozone concentration coincides reasonably well with the theoretical analysis on the atmospheric photochemical process, demonstrating the effectiveness of the procedure. An integrated model system that cooperates with CAMx will be established in our future work. 展开更多
关键词 comprehensive air quality model with extensions MULTI-SCALE OZONE air quality modeling PHOTOCHEMICAL
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Numerical modeling of metamorphic core complex formation:Implications for the destruction of the North China Craton 被引量:6
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作者 ZiQi Ma Gang Lu +1 位作者 JianFeng Yang Liang Zhao 《Earth and Planetary Physics》 EI CSCD 2022年第2期191-203,共13页
Widespread magmatism, metamorphic core complexes(MCCs), and significant lithospheric thinning occurred during the Mesozoic in the North China Craton(NCC). It has been suggested that the coeval exhumation of MCCs with ... Widespread magmatism, metamorphic core complexes(MCCs), and significant lithospheric thinning occurred during the Mesozoic in the North China Craton(NCC). It has been suggested that the coeval exhumation of MCCs with uniform northwest-southeast shear senses and magmatism probably resulted from a decratonization event during the retreat of the paleo-Pacific Plate. Here we used two-dimensional finite element thermomechanical numerical models to investigate critical parameters controlling the formation of MCCs under far-field extensional stress. We observed three end-member deformation modes: the MCC mode, the symmetric-dome mode, and the pure-shear mode. The MCC mode requires a Moho temperature of ≥700 ℃ and an extensional strain rate of ≥5 × 10^(-16)s^(-1), implying that the lithosphere had already thinned when the MCC was formed in the Mesozoic. Considering that the widespread MCCs have the same northwest-southeast extension direction in the NCC, we suggest that the MCCs are surface expressions of both large-scale extension and craton destruction and that rollback of the paleo-Pacific slab might be the common driving force. 展开更多
关键词 metamorphic core complex North China Craton numerical modeling extensION
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