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NUMERICAL SIMULATION FOR SHALLOW FLOW AND POLLUTANT DISPERSION BASED ON QUAD-TREE MESHES

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Journal of Hydrodynamics 2006年第2期18卷 161-169页

作者： LIU xiao-dong HUA Zu-lin State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Ministry of Education Key Laboratory of Integrated Regulation and Resource Development on Shallow LakesCollege of Environmental Science and Engineering Hohai UniversityNanjing 210098 China

A 2D depth-averaged flow-pollutant coupled model based on quad-tree meshes was established to accurately simulate flows in water areas with irregular natural boundaries in this paper. The grids were generated by recursive subdivision about seeding points. A new neighbor-finding algorithm was presented. The governing equations were discrctized in collocated conservative variables by using the finite volume method, and the normal flux of mass, momentum and pollutants across the interlace between cells were computed by a Godunov-type Flux Difference Splitting （FDS） scheme. The model was applied to simulate flow fields around a groin. The computed values are in agreement with observed data. The results indicate that quad-tree meshes have fine local resolution, high efficiency and easy local refinement. It is clear that the quad-tree grid model can offer gains in efficiency when applied to complex flow domains or strong shear flows. Finally the model is applied to flow fields and concentration fields simulation in Jiangsu Haizhou Bay. The simulated polluted area is matched well with observations. Therefore, this model can be used to predict flow and concentration fields of actual water area with irregular natural land boundaries.

关键词： quad-tree grid shallow flow numerical simulation dispersion Godunov-type

UUV水下动态布放回收流体动力性能数值模拟

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舰船科学技术 2024年第4期46卷 88-91页

作者：李永成李迎华王小庆潘子英肖冬林中国船舶科学研究中心江苏无锡214082 深海技术科学太湖实验室江苏无锡214082

UUV与水下对接装置对接的过程中存在双体干扰问题,非线性特征强烈。为了探明UUV在对接过程中流体动力随着对接姿态以及运动距离变化规律,本文借助Fluent软件中的动网格技术开展非定常工况下UUV动态回收过程的数值模拟研究。系统分析UUV... 详细信息

UUV与水下对接装置对接的过程中存在双体干扰问题,非线性特征强烈。为了探明UUV在对接过程中流体动力随着对接姿态以及运动距离变化规律,本文借助Fluent软件中的动网格技术开展非定常工况下UUV动态回收过程的数值模拟研究。系统分析UUV运动速度、运动姿态(主要是攻角)对其流体动力性能以及流场结构的影响。本文研究成果可为后续样机试验提供技术指导和理论支撑。

关键词： UUV 水下对接动态回收数值模拟

Phase Evolution and Magnetic Properties of Sn_(1-2x)Fe_xNb_xO_2(0.45≤x≤0.50)

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Chemical Research in Chinese Universities 2010年第6期26卷 876-879页

作者： WANG Yu JIA xiao-lin dong lin GUAN Shao-kang School of Materials Science and Engineering Zhengzhou University Zhengzhou 450001 P. R. China

Sn1-2xFexNbxO2（0.45≤x≤0.50） samples were prepared at 1000 ℃ via a simple chemical co-precipitation *** effects of the concentrations of Sn doped on the structures and magnetic properties of the samples have been investigated.A systematic variation from monoclinic to orthorhombic FeNbO4 structure was observed with increasing Sn *** phase evolutions were observed from monoclinic structure with x=0.50 to the coexistence of monoclinic and orthorhombic structures with x=0.48,0.47,0.46,and then to orthorhombic structure with x=*** behavior was observed for all the samples,and the magnetic ordering temperatures decrease with increasing Sn concentration,which further indicated the sequence of phase *** results suggest that the incorporation of Sn can stabilize the orthorhombic FeNbO4.

关键词： FeNbO4 Sn doping Structure Magnetic behavior

Coherent Beam Combining of Two Slab Laser Amplifiers and Second-Harmonic Phase Locking Based on a Multi-Dithering Technique

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Chinese Physics Letters 2011年第9期28卷 155-158页

作者： LI xiao xiao Hu dong xiao-lin MA Yan-Xing XU xiao-Jun College of Optoelectric Science and Engineering National University of Defense TechnologyChangsha 410073

Coherent beam combining(CBC)is an efficient way to scale the brightness of laser *** demonstrate the active phase locking CBC of two slab laser amplifiers based on the multi-dithering *** experimental investigation on the 102 W coherent beam combining of two slab amplifiers shows that the whole system in a closed loop performs well over a long time *** contrast of the coherent combined beam profile is about 87%and the combining efficiency is nearly 85%.In addition,the CBC of two green lasers is realized based on the second-harmonic generation of the phase locking pump *** the best of our knowledge,this is the first report about second-harmonic active phase locking,which indicates further potential applications of CBC.

关键词： technique pump locking

MB_(8)^(0/-)(M=Li、Na、Rb、Cs)团簇的几何结构和电子特性的研究

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原子与分子物理学报 2024年第5期41卷 85-93页

作者：李媛媛胡燕飞袁玉全董晓林四川轻化工大学物理与电子工程学院自贡643000 成都理工大学数理学院成都610059

本文结合CALYPSO软件和密度泛函理论,详细研究了MB_(8)^(0/-)(M=Li、Na、Rb、Cs)团簇的几何结构和成键特性.结构分析结果表明,MB_(8)^(0/-)团簇的基态结构都具有相似的几何构型,均为七棱锥状结构,并且随着掺杂原子的原子序数的增加,其M-... 详细信息

本文结合CALYPSO软件和密度泛函理论,详细研究了MB_(8)^(0/-)(M=Li、Na、Rb、Cs)团簇的几何结构和成键特性.结构分析结果表明,MB_(8)^(0/-)团簇的基态结构都具有相似的几何构型,均为七棱锥状结构,并且随着掺杂原子的原子序数的增加,其M-B键的键长呈增加的趋势.通过稳定性分析,我们发现LiB_(8)^(-)团簇的最高占据分子轨道与最低未占据分子轨道之间的能隙(HOMO-LOMO能隙)以及结合能(E_(b))最大,因此这个团簇是体系中相对稳定的结构.电荷转移分析表明,掺杂的碱金属原子在所研究体系中充当着电子供体的角色.最后,成键分析的结果显示,LiB_(8)^(-)团簇的稳定性来源于B原子的2p轨道以及Li原子的2s和2p轨道在HOMO和LUMO的高贡献;适应性自然密度划分分析显示,B和Li原子都参与了成键,这同样有利于LiB_(8)^(-1)团簇的高稳定性的形成.希望我们的工作能为进一步研究碱金属掺杂硼团簇提供指导和帮助.

关键词： CALYPSO 第一性原理掺杂硼团簇稳定性分析

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Two New C_(19)-Diterpenoid Alkaloids from Delphinium davidii Franch

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Chinese Chemical Letters 2006年第11期17卷 1473-1476页

作者： xiao Xia LIANC dong lin CHEN Feng Peng WANG Department of Chemistry of Medicinal Natural Products West China College of Pharmacy Sichuan University Chengdu 610041

Two new C19-diterpenoid alkaloids, davidisines A （1） and B （2） along with thirteen known alkaloids were isolated from the whole herb of Delphinium davidii Franch. Their structures were established by spectral meth... 详细信息

关键词： Delphinium davidii Franch. C19-diterpenoid alkaloids davidisine A davidisine B

Bigflow: A General Optimization Layer for Distributed Computing Frameworks

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Journal of Computer Science & Technology 2020年第2期35卷 453-467页

作者： Yun-Cong Zhang xiao-Yang Wang Cong Wang Yao Xu Jian-Wei Zhang xiao-dong lin Guang-Yu Sun Gong-lin Zheng Shan-Hui Yin Xian-Jin Ye Li Li Zhan Song dong-dong Miao Baidu Inc. Beijing 100193China Center for Energy-Efficient Computing and Applications Peking UniversityBeijing 100871China

As data volumes grow rapidly, distributed computations are widely employed in data-centers to provide cheap and efficient methods to process large-scale parallel datasets. Various computation models have been proposed to improve the abstraction of distributed datasets and hide the details of parallelism. However, most of them follow the single-layer partitioning method, which limits developers to express a multi-level partitioning operation succinctly. To overcome the problem, we present the NDD (Nested Distributed Dataset) data model. It is a more compact and expressive extension of Spark RDD (Resilient Distributed Dataset), in order to remove the burden on developers to manually write the logic for multi-level partitioning cases. Base on the NDD model, we develop an open-source framework called Bigflow, which serves as an optimization layer over computation engines from most widely used processing frameworks. With the help of Bigflow, some advanced optimization techniques, which may only be applied by experienced programmers manually, are enabled automatically in a distributed data processing job. Currently, Bigflow is processing about 3 PB data volumes daily in the data-centers of Baidu. According to customer experience, it can significantly save code length and improve performance over the intuitive programming style.

关键词： distributed computing programming model optimization technique

Local injection therapy for hepatocellular carcinoma

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Hepatobiliary & Pancreatic Diseases International 2006年第1期5卷 16-21页

作者： xiao-dong lin and Li-Wu lin Department of Ultrasound, Union Hospital of Fujian Medical University, Fuzhou 350001, China Department of Ultrasound Union Hospital of Fujian Medical University Fuzhou 350001 China.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world and ranks the third most common cause of cancer-related death. Surgical resection, liver transplantation and percutaneous ablation are generally considered the only curative treatment for early stage HCC. Besides the limitations of insufficient organ donors and a long waiting time for liver transplantation, however, resection is applied only to patients with good hepatic reserve and localized tumors, with a resectability of 30%. DATA SOURCES: Local ablation therapy, which is minimally invasive but contributes to the significant improvement of survival in patients with unresectable tumor, hasbeen widely used in treating small HCC. Among the techniques of local therapy, percutaneous ethanol injection (PEI) with a complete response in 80% of HCCs less than 3 cm has been accepted as an alternative to surgery in patients with small HCC. Moreover, percutaneous hepatic quantified ethanol injection (PHQEI) or PEI according to the standard criteria has been confirmed to benefit patients with HCC, especially when quantified ethanol is given at a short interval (QESI, the interval was 2-3 days). RESULT: Several limitations related to local percutaneous methods may result in incomplete therapeutic effect in case of larger HCC nodules (>3 cm). CONCLUSION: The combined use of different methods according to the clinical status of patients or tumors may be essential to the effective treatment of HCC.

关键词： carcinoma, hepatocellular radical therapy percutaneous ablation percutaneous ethanol injection percutaneous acetic acid injection

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公路建设项目全程环境管理体系研究

中国公路学报 2008年第1期21卷 100-105页

作者：董小林长安大学环境科学与工程学院陕西西安710064

为了加强公路交通环境保护工作,减少公路建设项目全程的自然环境影响与社会环境影响,促进公路环境管理的规范性和有效性,结合公路建设前期、建设期和运营期的环境保护工作要求,从环境计划管理、环境质量管理、环境技术管理和环保投资管... 详细信息

为了加强公路交通环境保护工作,减少公路建设项目全程的自然环境影响与社会环境影响,促进公路环境管理的规范性和有效性,结合公路建设前期、建设期和运营期的环境保护工作要求,从环境计划管理、环境质量管理、环境技术管理和环保投资管理等方面,建立了公路建设项目全程环境管理体系。分析了公路建设项目全程环境影响以及公路环境管理现状,提出了建设项目全程环境管理的概念,对公路建设项目全程环境管理体系的组成部分进行了分析。研究结果表明:公路建设项目全程环境管理体系为公路交通环境保护提供了全面的支持和保障,有利于公路建设项目经济效益、社会效益和环境效益的协调统一。

关键词：工程管理公路建设项目理论分析全程环境管理交通环境保护管理体系