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Seismic design of Xiluodu ultra-high arch dam

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Water Science and Engineering 2018年第4期11卷 288-301页

作者： Ren-kun Wang Lin Chen Chong Zhang PowerChina Chengdu Engineering corporation Limited Chengdu 610072 China

The 285.5 m-high Xiluodu Arch Dam is located in a seismic region along the Jinsha River in China, where the horizontal components of peak ground accelerations for design and checking earthquakes have been estimated to be 0.355 g and 0.423 g, respectively( g is the gravitational acceleration). The ground motion parameters of design and checking earthquakes are defined by exceedance probabilities of 2% over 100 years and 1% over 100 years, respectively. The dam shape was first selected and optimized through static analysis of the basic load combinations, and then adjusted after taking into account the seismic loads. The dam should be operational during and after the design earthquake with or without minor repairs, and maintain local and global stabilities during an extreme earthquake. Both linear elastic dynamic analysis and nonlinear dynamic analysis considering radiation damping, contraction joints, and material nonlinearity were conducted to assess the stress in the arch *** dynamic analysis shows that the maximum dynamic compressive stresses are less than the allowable levels, while the area with tensile stress over the limit is less than 15% of the dam surface and the maximum contraction openings range from 10 mm to 25 mm. The arch dam has sufficient earthquake-resistance capacity and meets the safety requirements. Nevertheless, steel reinforcement has been provided at the dam toe and in the zones of high tensile stress on the dam surface out of extra precaution.

关键词： Seismic design Nonlinear dynamic analysis Dam shape optimization Seismic strengthening Xiluodu arch dam

Protective effects ofLactobacillus plantarum against epithelial barrier dysfunction of human colon cell line NCM460

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World Journal of Gastroenterology 2010年第45期16卷 5759-5765页

作者： Mary Pat Moyer INCELL corporation San AntonioTX 78249United States

AIM: To investigate the effects of Lactobacillus plantarum (L. plantarum ) in the intestinal permeability and expression of tight junction (TJ) using the normal human colon cell line NCM460. METHODS: Paracellular permeability of NCM460 monolayers was determined by transepithelial electrical resistance and dextran permeability. Expression of TJ proteins in NCM460 cell monolayers was detected by Western blotting and quantitative real-time polymerase chain ***: L. plantarum played an important role in increasing transepithelial electrical resistance and decreasing the permeability to macromolecules of NCM460 monolayers against the disruption caused by enteropathogenic Escherichia coli (E. coli ) or enteroinvasive E. coli . L. plantarum also prevented the decrease in the expression of TJ proteins and F-actin in NCM460 ***: L. plantarum can protect against dysfunction of NCM460 intestinal epithelial barrier caused by enteropathogenic E. coli or enteroinvasive E. coli , and thus can be a potential candidate of therapeutic agents for the treatment of intestinal diseases.

关键词： Lactobacillus plantarum NCM460 Tight junction Intestinal barrier

Emission-Based Scatter Correction in SPECT Imaging

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Tsinghua Science and Technology 2010年第1期15卷 1-10页

作者： Hetal Babla Richard Conwell Digirad corporation PowayCA 92064USA

Scatter correction in single photon emission computed tomography （SPECT） has been focused on either using multiple-window acquisition technique or the scatter modeling technique in iterative image reconstruction. We propose a technique that uses ：only the emission data for scatter correction in SPECT. We assume that the scatter data can be approximated by convolving the primary data with a scatter kernel followed by the normalization using the scatter-to-primary ratio （SPR）, Since the emission data is the superposition of the primary data and the scatter data, the convolution normalization process approximately results in the sum of the scatter data and a convolved version of scatter data with the kernel. By applying a proper scaling factor, we can make the estimation approximately equal to or less than the scatter data anywhere in the projection domain. Phantom and patient cardiac SPECT studies show that using the proposed emission-based scatter estimation can effectively reduce the scatter-introduced background in the reconstructed images. And additionally, the computational time for scatter correction is negligible as compared to no scatter correction in iterative image reconstruction.

关键词： SPECT emission-based scatter correction iterative image reconstruction

Finite element analysis for wellbore stability of transversely isotropic rock with hydraulic-mechanical-damage coupling

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Science China(Technological Sciences) 2017年第1期60卷 133-145页

作者： WANG YongLiang LIUZhanLi YANG HengLin ZHUANG Zhuo Drilling Research Institute China National Petroleum Corporation Beijing 100195 China

The finite element analysis （FEA） technology by hydraulic-mechanical-damage （HMD） coupling is proposed in this paper for wellbore stability analysis of transversely isotropic rock, developed basing on the recently established FEA technology for iso- tropic rock. The finite element （FE） solutions of numerical wellbore model, damage tensor calculation and Pariseau strength criterion for transversely isotropic rock are developed for researching the wellbore failure characteristics and computing the collapse and fracture pressure of laminated rock as shale reservoirs. The classic Blot constitutive for rock as porous medium is introduced to establish a set of FE equations coupling with elastic solid deformation and seepage flow. To be in accord with the inclined wellbore situation, the coordinate transformation for global, wellbore, in-situ stress and transversely isotropic for- mation coordinate systems is established for describing the in-situ stress field and the results in laminated rock. To be in accord with the practical situation, a three-dimensional FIE model is developed, in which several other auxiliary technologies are com- prehensively utilized, e.g., the typical Weibull distribution function for heterogeneous material description and adaptive tech- nology for mesh refinement. The damage tensor calculation technology for transversely isotropic rock are realized from the well-developed continuum damage variable of isotropic rock. The rock is subsequently developed into a novel conceptual and practical model considering the stress and permeability with the damage. The proposed method utilizing Parisean strength cri- terion fully reflects the strength parameters parallel or perpendicular to bedding of the transversely isotropic rock. To this end, an effective and reliable numerically three-step FEA strategy is well established. Numerical examples are given to show that the proposed method can establish efficient and applicable FE model and be suitable for analyz

关键词： finite element analysis wellbore stability transversely isotropic rock damage tensor hydraulic-mechanical-damagecoupling

A new shallow trench and planar gate MOSFET structure based on VDMOS technology

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Journal of Semiconductors 2011年第2期32卷 53-56页

作者：王彩琳孙丞 Department of Electronics Engineering Xi'an University of Technology CSMC Technologies corporation

This paper proposes a new shallow trench and planar gate MOSFET （TPMOS） structure based on VD- MOS technology, in which the shallow trench is located at the center of the n- drift region between the cells under a planar polysilicon gate. Compared with the conventional VDMOS, the proposed TPMOS device not only im- proves obviously the trade-off relation between on-resistance and breakdown voltage, and reduces the dependence of on-resistance and breakdown voltage on gate length, but also the manufacture process is compatible with that of the VDMOS without a shallow trench, thus the proposed TPMOS can offer more freedom in device design and fabrication.

关键词： power MOSFET shallow trench planar gate

Velocity model and time-depth conversion for the northwestern South China Sea deepwater areas

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Acta Oceanologica Sinica 2015年第4期34卷 56-61页

作者： LIU Aiqun CHEN Dianyuan LI Wentuo FAN Caiwei HE Jianwei Zhanjiang Branch of China National Offshore Oil corporation Limited

There are rich natural gas resources in the northwestern South China Sea deepwater areas, with poor degree of exploration. Because of the unique tectonic, sedimentary background of the region, velocity model building and time-depth conversion have been an important and difficult problem for a long time. Recent researches in this direction have revealed three major problems for deepwater areas, i.e., the way to determine error correction for drilling velocity, the optimization of velocity modeling, and the understanding and analysis of velocity variations in the slope areas. The present contribution proposes technical solutions to the problems：（1） velocity correction version can be established by analyzing the geology, reservoir, water depths and velocity spectrum characteristics;（2） a unified method can be adopted to analyze the velocity variation patterns in drilled pale structural positions;and （3） across-layer velocity is analyzed to establish the velocity model individually for each of the layers. Such a solution is applicable, as shown in an example from the northwestern South China Sea deepwater areas, in which an improved prediction precision is obtained.

关键词： time-depth conversion velocity modeling deepwater areas continental slope South China Sea

Exploration of Complicated Oil and Gas Fields

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Acta Geologica Sinica(English Edition) 1989年第1期63卷 65-77页

作者： Zhang Xiangning China National Oil & Gas Exploration & Development corporation, Beijing Liu Linqun China National Oil & Gas Exploration & Development corporation Beijing

Complicated oil and gas fields occupy an important position in oil and gas exploration. In this paper, complicated oil and gas fields are grouped into four types: fault-block, lithologic, stratigraphic and fissure types. On the basis of the new theory of petroleum geological exploration in composite oil and gas accumulation areas within continental basins, a new exploration sequence suitable for complicated oil and gas fields has been established, which comprises four stages:(1) initial exploration;(2) preliminary exploration;(3) early step-by-step exploration and development: and(4) late step-by-step exploration and development. The idea of cybernetics has been taken to control various links of a systematic exploration project so as to fully, effectively and comprehensively utilize the new exploration techniques, eventually realizing the optimization of exploration with the aim of raising the efficiency of exploration of complicated oil and gas fields.

关键词： Pro test Exploration of Complicated Oil and Gas Fields

Characteristics of deformation joining of aluminum-stainless steel composite sheet

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中国有色金属学会会刊：英文版 2003年第6期13卷 1385-1388页

作者：李培武孙康宁李爱民李中友刘秀忠栾新民徐秀丽 Material Science and Engineering Institute Qingdao Metalforming Machinery Group corporation

In order to study the characteristics of deformation joining of aluminum-stainless steel composite sheet, an applied example of this composite sheet was given. The conditions of the composite sheet were discussed, the optical micrographs and scanning electron micrographs were examined by contrast ways of deformation joining and braze joining. Simultaneously the analysis of energy spectrum was also conducted. The results indicate that the deformation joining composite sheet possesses high bonding strength, good corrosion resistance, less inclusions and less microcracks.

关键词：铝合金不锈钢复合板变形特征接头

Novel Approach to Minimize the Memory Requirements of Frequent Subgraph Mining Techniques

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Chinese Journal of Electronics 2021年第2期30卷 258-267页

作者： B?LG?N Turgay Tugay O?UZ Murat Department of Computer Engineering Bursa Technical University Microsoft corporation Turkey Branch

Frequent subgraph mining(FSM) is a subset of the graph mining domain that is extensively used for graph classification and clustering. Over the past decade, many efficient FSM algorithms have been developed with improvements generally focused on reducing the time complexity by changing the algorithm structure or using parallel programming techniques. FSM algorithms also require high memory consumption, which is another problem that should be solved. In this paper, we propose a new approach called Predictive dynamic sized structure packing(PDSSP) to minimize the memory needs of FSM algorithms. Our approach redesigns the internal data structures of FSM algorithms without making algorithmic modifications. PDSSP offers two contributions. The first is the Dynamic Sized Integer Type, a newly designed unsigned integer data type, and the second is a data structure packing technique to change the behavior of the compiler. We examined the effectiveness and efficiency of the PDSSP approach by experimentally embedding it into two state-of-the-art algorithms, g Span and *** compared our implementations to the performance of the originals. Nearly all results show that our proposed implementation consumes less memory at each support level, suggesting that PDSSP extensions could save memory, with peak memory usage decreasing up to 38% depending on the dataset.

关键词： data structures algorithmic modifications high memory consumption graph mining domain Dynamic Sized Integer Type Predictive dynamic sized structure packing internal data structures graph classification parallel programming peak memory usage memory requirements PDSSP extensions finite state machines graph theory PDSSP approach algorithm structure newly designed unsigned integer data type data mining data structure packing technique efficient FSM algorithms clustering frequent subgraph mining techniques