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Quantification of coarse aggregate shape in concrete

Frontiers of Structural and Civil Engineering 2014年第3期8卷 308-321页

作者： Xianglin GU Yvonne tran Li HONG Department of Structural Engineering Tongii University Shanghai 200092 China

The objective of this study is to choose indices for the characterization of aggregate form and angularity for large scale application. For this purpose, several parameters for aggregate form and angularity featured in previous research are presented. Then, based on these established parameters, 200 coarse quartzite aggregates are analyzed herein by using image processing technology. This paper also analyzes the statistical distributions of parameters for aggregate form and angularity as well as the correlation between form and angularity parameters. It was determined that the parameters for form or angularity of coarse aggregates could be fitted by either normal distribution or log-normal distribution at a 95% confidence level, Some of the form parameters were influenced by changes in angularity characteristics, while aspect ratio and angularity using outline slope, area ratio and radius angularity index, and aspect ratio and angularity index were independent of each other, respectively; and consequently, the independent parameters could be used to quantify the aggregate form and angularity for the purpose to study the influence of aggregate shape on the mechanical behavior of concrete. Furthermore, results from this study＇s in-depth investigations showed that the aspect ratio and the angularity index can further understanding of the effects of coarse aggregates form and angularity on concrete mechanical properties, respectively. Finally, coarse aggregates with the same content, type and surfaces texture, but different aspect ratios and angularity indices were used to study the influence of coarse aggregate form and angularity on the behavior of concrete. It was revealed that the splitting tensile strength of concrete increased with increases in the aspect ratio or angularity index of coarse aggregates.

关键词： coarse aggregate form angularity digital image analysis statistical distribution splitting tensile strength

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The tropical-subtropical evergreen forest transition in East Asia:An exploration

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Plant Diversity 2020年第4期42卷 255-280页

作者： Peter Ashton hua.Zhu Arnold Arboretum Harvard UniversityRoyal Botanic GardensKewUK Center for Integrative Biology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesYunnanPR China

The transition from tropical to subtropical(warm temperate)evergreen forests is more clearly apparent in East Asia,fromNepal to the western Pacific coast,than elsewhere in the *** review the nature of this transition and hypothesize the physical,ultimately climatic,factors thatmay maintain it,with a special focus on how the increasing instability and warming of climates will affect these forests.A primary climatic mediator of the transition is proposed,thereby offering a testable hypothesis for the climateeforest transition *** is known of this transition is summarized in context of the primary climatic mediators of elevational zonation of forest formations in equatorial Asia to the tree line,in the Himalaya at the India-Indo-Burma northern tropical margin,and as both elevational and latitudinal zonation in southern *** secondary edaphic and other physical changes are described for the Himalaya,and hypothesized for southern *** forest ecotones are seen to be primarily defined by tree floristic change,on which account changes in structure and physiognomy are *** montane tropical-subtropical transition in the Himalaya is narrowand observed to correlate with an as yet ill-defined frost line.A distinct tropical-subtropical transition forest is recognized in the southwest *** is a total change in canopy species at the Himalayan ecotone,but subcanopy tropical species persist along an elevational decline of c.400 *** latitudinal transition in South China is analogous,but here the tropical subcanopy component extends north over ten degrees latitude,albeit in *** tropical-subtropical transition is uniquely clear in East Asia because here alone a tropical wet summer-dry winter monsoon extends to 35north latitude,encompassing the subtropical evergreen forest,whereas subtropical evergreen forests elsewhere exist under drier temperate summer climate regimes.

关键词： Tropical Subtropical Forest transition Ecotone East Asia

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A new method in highway route design:joining circular arcs by a single C-Bézier curve with shape parameter

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第4期10卷 562-569页

作者： hua.hui CAI Guo-jin WANG Institute of Computer Graphics and Image Processing State Key Lab of CAD & CG Zhejiang University Hangzhou 310027 China

We constructed a single C-Bezier curve with a shape parameter for G^2 joining two circular arcs. It was shown that an S-shaped transition curve, which is able to manage a broader scope about two circle radii than the Bezier curves, has no curvature extrema, while a C-shaped transition curve has a single curvature extremum. Regarding the two kinds of curves, specific algorithms were presented in detail, strict mathematical proofs were given, and the effectiveness of the method was shown by examples This method has the following three advantages：（1） the pattern is unified; （2） the parameter able to adjust the shape of the transition curve is available; （3） the transition curve is only a single segment, and the algorithm can be formulated as a low order equation to be solved for its positive root. These advantages make the method simple and easy to implement.

关键词： transition curve C-Bezier curve Monotone curvature Shape parameter

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Implicit high-order discontinuous Galerkin method with HWENO type limiters for steady viscous flow simulations

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Acta Mechanica Sinica 2013年第4期29卷 526-533页

作者： Zhen-hua.Jiang Chao Yan Jian Yu College of Aeronautics Science and Engineering Beijing University of Aeronautics and Astronautics

Two types of implicit algorithms have been im- proved for high order discontinuous Galerkin （DG） method to solve compressible Navier-Stokes （NS） equations on tri- angular grids. A block lower-upper symmetric Gauss- Seidel （BLU-SGS） approach is implemented as a nonlin- ear iterative scheme. And a modified LU-SGS （LLU-SGS） approach is suggested to reduce the memory requirements while retain the good convergence performance of the origi- nal LU-SGS approach. Both implicit schemes have the sig- nificant advantage that only the diagonal block matrix is stored. The resulting implicit high-order DG methods are applied, in combination with Hermite weighted essentially non-oscillatory （HWENO） limiters, to solve viscous flow problems. Numerical results demonstrate that the present implicit methods are able to achieve significant efficiency improvements over explicit counterparts and for viscous flows with shocks, and the HWENO limiters can be used to achieve the desired essentially non-oscillatory shock tran- sition and the designed high-order accuracy simultaneously.

关键词： Discontinuous Galerkin (DG) scheme ~ Implicitmethod ~ HWENO ~ High order ~ Unstructured grids

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A universal method for rapid and large‐scale growth of layered crystals

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SmartMat 2020年第1期1卷 77-84页

作者： Apoorva Chaturvedi Bo Chen Keke Zhang Qiyuan He Gwang‐Hyeon Nam Lu You Zhua.gchai Lai Chaoliang Tan Thu Ha tran Guigao Liu Jiadong Zhou Zheng Liu Junling Wang Edwin H.T.Teo hua.Zhang Center for Programmable Materials School of Materials Science and EngineeringNanyang Technological UniversitySingaporeSingapore Department of Chemistry City University of Hong KongHong KongChina Department of Materials Science and Engineering City University of Hong KongHong KongChina Jiangsu Key Laboratory of Thin Films School of Physical Science and TechnologySoochow UniversitySuzhouChina Department of Electrical Engineering City University of Hong KongHong KongChina Department of Physics Southern University of Science and TechnologyShenzhenGuangdongChina School of Electric and Electronic Engineering Nanyang Technological UniversitySingaporeSingapore Hong Kong Branch of National Precious Metals Material Engineering Research Center(NPMM) City University of Hong KongHong KongChina

Layered van der Waals(vdW)materials,consisting of atomically thin layers,are of paramount importance in physics,chemistry,and materials science owing to their unique properties and various promising ***,their fast and large‐scale growth via a general approach is still a big challenge,severely limiting their practical ***,we report a universal method for rapid(~60 min)and large‐scale(gram scale)growth of phase‐pure,high‐crystalline layered vdW materials from their elementary powders via microwave plasma heating in sealed *** method can be used for growth of 30 compounds with different components(binary,ternary,and quaternary)and *** ferroelectric and transport properties of mechanically exfoliated flakes validate the high crystal quality of the grown *** study provides a general strategy for the fast and large‐scale growth of layered vdW materials with appealing physiochemical properties,which could be used for various promising applications.

关键词： 2D materials ferroelectric field‐effect transistors layered compounds universal method

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GIS在移动蜂窝网络中的应用研究

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测绘科学 2012年第2期37卷 133-137页

作者：陈晓勇吴华玲 tran Minh Tri 东华理工大学测绘工程学院江西抚州344000 亚洲理工学院工程技术学院

GIS在移动蜂窝网络规划中有重要应用,本文旨在研究以最低的投资和维护费用,确定GIS最佳解决方案用以改善蜂窝网络的传播质量。本文利用GIS能将蜂窝网络数据库中空间与非空间数据相结合的优势,提供必要的参数,更准确地预测蜂窝网络的覆... 详细信息

GIS在移动蜂窝网络规划中有重要应用,本文旨在研究以最低的投资和维护费用,确定GIS最佳解决方案用以改善蜂窝网络的传播质量。本文利用GIS能将蜂窝网络数据库中空间与非空间数据相结合的优势,提供必要的参数,更准确地预测蜂窝网络的覆盖范围。本文研究对象为越南胡志明市的部分区域,实验成功开发出预测移动蜂窝网络覆盖范围的基础地理信息系统模型,实现了预测信号强度的可视化,分析了场强覆盖范围,并显示了研究区域中每个小区站的可能切换区域。实验结果表明,GIS模型在移动通信尤其对小区站覆盖范围预测是非常有用的。

关键词：移动蜂窝网网络规划 GIS 场强覆盖区切换区

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Effects of Qingshen granules on Janus Kinase/signal transducer and activator of transcription signaling pathway in rats with unilateral ureteral obstruction

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Journal of Traditional Chinese Medicine 2018年第2期38卷 182-189页

作者： Wang Yiping Wang Dong Jin hua.Yu Min Zhang Lei Department of Nephrology the First Hospital Affiliated to Anhui University of Traditional Chinese Medicine Department of Nephrology the Third Hospital Affiliated to Anhui University of Traditional Chinese Medicine

OBJECTIVE:To investigate the effects of Qingshen granules(QSG) on janus kinase/signal transducer and activator of transcription(JAK/STAT) signaling pathway in a rat model of unilateral ureteral obstruction(UUO).METHODS: Sixty male Sprague-Dawley rats wererandomly divided into six groups, with 10 animals in each group: the untreated sham-operated normal control group; the untreated UUO model control group, the high dose QSG-treated(16 gdm dose QSG-·kg-1-1) UUO group; the mediutreate·d(8 g·kg-1·d-1) UUO group; the low dose QSG-treated(4 g·kg-1·d-1) UUO group; and the valsartan-treated group(20 mg·kg-1·d-1). The two untreated control groups received physiological saline(1 m L/100 g per day). All the rats were sacrificed after a 4-week course of treatment. Serum creatinine and leptin; protein expressions of leptin receptor(OB-R), p-JAK2, p-STAT3, nuclear factors-κBp6(NF-k Bp65), and monocytechemotatic protein-1(MCP-1); m RNA of JAK2, STAT3, calcium-dependent adhesion(E-cadherin), alphasmooth muscle actin(α-SMA) in the kidney tissues;and the expressions of type ronectin(FN) and the pⅣat collagen(Col-homorphologyⅣ)and fib in kidney tissues were ***: Compared with the normal group, the BUN, Scr, and serum leptin levels and the expressions of MCP-1, p-JAK2, p-STAT3, NF-k Bp65 and OB-R in renal tissues, and the m RNA expressions of leptin, JAK2 protein, STAT3 protein, α-SMA protein in model group were significantly higher(P < 0.01)in the UUO model group. These parameters were significantly reduced in all the QSG-treated groups and the valsartan-treated group than the UUO model group(P < 0.05 or P < 0.01), with the lowest levels found in the medium dose QSG-treated group(P < 0.05). However, the expression levels of E-cadherin, FN, and Col-Ⅳ in the renal tissues were contrary to the expressions described above. Se-vere pathological injury was evident in the renal tissues of UUO model rats, which was alleviated in the QSG-treated and valsartan-treated groups, with t

关键词： Renalscription factors granulesfibrosis Janus kinases Signal transduction STAT tran-Qingshen

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农用车柔性底盘姿态切换参数对切换精度与时间的影响及其优化

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农业工程学报 2019年第5期35卷 51-61页

作者：李翊宁郭康权陈文强瞿济伟高华西北农林科技大学机械与电子工程学院杨凌712100 陕西省农业装备工程技术研究中心杨凌712100 第一越南苏联职业技术学院电子工程学院福安市15910

为了研究农用车柔性底盘的姿态切换运行特性,该文进行了柔性底盘姿态切换分析和基于二代样机在硬化路面上的姿态切换试验,建立了姿态切换状态模型,并通过层次分析法和遗传算法优化了切换参数,研究了不同平移角度、电机转速、切换角度、... 详细信息

为了研究农用车柔性底盘的姿态切换运行特性,该文进行了柔性底盘姿态切换分析和基于二代样机在硬化路面上的姿态切换试验,建立了姿态切换状态模型,并通过层次分析法和遗传算法优化了切换参数,研究了不同平移角度、电机转速、切换角度、平移速度和回转速度条件下的切换精度和切换时间,得到各因素及其交互作用对农用车柔性底盘姿态切换的影响和不同切换参数的相互配合关系。结果表明:影响准备与恢复精度的主次因素为电机转速>平移角度,影响准备与恢复时间的主次因素为平移角度>电机转速;横行姿态的平移速度对其横行精度和时间都有极显著的影响,任意平移角度下,横行姿态的电机最优转速为5.4 r/min,最优平移速度为3.45 m/s;影响原地回转姿态的回转精度主次因素为:切换角度>回转速度;影响原地回转姿态的回转时间主次因素为:切换角度>回转速度>交互作用;任意平移角度下,原地回转姿态的最优电机转速为5.4 r/min,当切换角度?r为0～85°时,最优回转速度为(0.003 3βr+0.506 8) rad/s,当切换角度大于等于85°时,最优回转速度为0.78rad/s。优化参数对比结果表明:横行姿态中,优化参数组的试验结果在综合精度方面与精度优先组持平并高出时间优先组4.16%,在综合时间方面与时间优先组持平并少于精度优先组17 110 ms;原地回转姿态中,优化参数组的试验结果在综合精度方面与精度优先组持平并高出时间优先组5.15%,在综合时间方面分别少于时间优先组和精度优先组646和996 ms。优化后的姿态切换参数能够保证柔性底盘在略微损失姿态切换精度的情况下,以较快的姿态切换效率完成其姿态切换过程。

关键词：农业机械车辆柔性底盘姿态切换参数优化层次分析法遗传算法

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Generation and expression analysis of BAC humanized mice carrying HLA-DP401 haplotype

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Animal Models and Experimental Medicine 2021年第2期4卷 116-128页

作者： Feng Li Meng-min Zhu Bo-wen Niu Ling-ling Liu Xiu-hua.Peng hua.Yang Bo-yin Qin Meixiang Wang Xiaonan Ren Xiaohui Zhou Department of Laboratory Animal Science Shanghai Public Health Clinical CenterFudan UniveristyShanghaiChina Department of Scientific Research Shanghai Public Health Clinical CenterFudan UniveristyShanghaiChina

Background:Human leukocyte antigen(HLA)-DP is much less studied than other HLA class Ⅱ antigens,that is,HLA-DR and HLA-DQ,***,the accumulating data have suggested the important roles of DP-restricted responses in the context of cancer,allergy,and infectious *** of animal models expressing these genes as authentic cis-haplotypes blocks our understanding for the role of HLA-DP haplotypes in ***:To explore the potential cis-acting control elements involved in the tran-scriptional regulation of the HLA-DPA1/DPB1 gene,we performed the expression analysis using bacterial artificial chromosome(BAC)-based transgenic humanized mice in the C57BL/6 background,which carried the entire HLA-DP401 gene *** further developed a mouse model of Staphylococcus aureus pneumonia in HLA-DP401 humanized transgenic mice,and performed the analysis on the expres-sion pattern of HLA-DP401 and immunological responses in the ***:In this study,we screened and identified a BAC clone spanning the entire HLA-DP gene *** from this clone was analyzed for integrity by pulsed-field gel electrophoresis and then microinjected into fertilized mouse oocytes to produce transgenic founder *** sets of PCR primers for regional markers with an average distance of 15 kb between each primer were used to confirm the integrity of the transgene in the five transgenic lines carrying the HLA-DPA1/DPB1 *** copy numbers were determined by real-time PCR ***-DP401 gene expression was analyzed at the mRNA and protein *** infection with S aureus Newman did not alter the percentage of immune cells in the spleen and thymus from the HLA-DP401-H2-Aβ1 humanized *** expression of HLA-DP401 was observed in the thymus of the humanized mice infected by S ***:We generated several BAC transgenic mice,and analyzed the expres-sion of HLA-DPA1/DPB1 in those mice.A model of S aureus-induced pneumonia in the HLA-DP401-H2-Aβ1^

关键词： bacterial artificial chromosome(BAC) gene expression HLA-DP4 humanized mice Staphylococcus aureus pneumonia

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Acute exposure to high-peak-power pulsed microwaves affecting the histamine H_3 receptor expression in rat hippocampus

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Nuclear Science and Techniques 2006年第4期17卷 227-231页

作者： YU Xiao-Dong LI Bo LI De-hua.HE Qi-Yi YU Zheng-Ping Department of Occupational Health School of Preventive Medicine Third Military. Medical University Chongqing 400038China Chongqing Key Laboratory of Animal Sciences School of Biological Science Chongqing Normal University Chongqing 400037 China

In the Morris Water Maze test, high-peak-power pulsed microwave (MW)-exposed rats displayed some learning and memory behavior dysfunctions, and their escape time and swimming distance to the submerged platform were longer than those of the sham-exposed rats. To understand the molecular mechanism involved, the reverse tran- scription-polymerase chain reaction (RT-PCR) and the Western-blotting technique were used for investigating the mRNA and protein expression patterns of the histamine H3 receptor (H3R) in rat hippocampus. High-peak-power pulsed microwave-exposure did not remarkably lead to the change in expression of H3R mRNA in rat hippocampi; however, it promoted the up-regulatory expression of the H3R protein, which was possibly triggered through the mi- togen-activated protein kinase (MAPK) pathways. Therefore, further investigation of the molecular mechanism of the MW effects on the learning and memory behaviors is required.

关键词：组胺H3受体大鼠海马微波辐照表达

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