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Analysis of Dynamics and Driving Factors of Wetland Landscape in Zoige,Eastern Qinghai-Tibetan Plateau

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Journal of Mountain Science 2009年第1期6卷 42-55页

作者： QIU Pengfei WU Ning LUO Peng WANG zuyuan LI Maihe Chengdu Institute of Biology Chinese Academy of Sciences Chengdu 610041 China Sichuan Instute of Territorial Survey and Plan Chengdu 610031 China Swiss Federal Research Institute WSL Zuercherstrasse 111 CH-89o3 Birmensdorf Switzerland Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China

Zoige Wetland is one of the largest plateau wetlands in the world. This paper provides a dynamic analysis of spatial and temporal patterns of the wetland in Zoige, Eastern Qinghai-Tibetan Plateau, supported by ERDAS8.7 and ArcGIS9.0. It is the first comparative analysis of a system of rapidly changing wetland with landscape patterns in Zoige, using 3 classified landsat Thematic Mapper images of 1977, 1994 and 2001. The classified images were used to generate wetland distributing maps, and shape index （S）, diversity index （H）, dominance index （D）, evenness index （E）, fragmentation index （F） and fractal dimension （Fd） were calculated and analyzed spatiotemporally across pure grazing area in Zoige for each landscape type and in different periods （before 1977, during 1977-1994 and 1994-2001）, as well as the driving forces of natural and anthropogenic. The study shows that for a comprehensive understanding of the shapes and trajectories of the shrinking and desertificated land expansion of the wetland, a spatiotemporal landscape metrics analysis in different periods is an improvement than only with landscape changing rates. This type of analysis can also be used to infer underlying social, economic, and political processes that drive the observed wetland forms. The results indicate that wetland patterns can be changed over relatively short periods of time. The total area of lake reduced by 164.86 km^2, grassland extended by 141.74 km^2, semi-marsh extended by 105.94 km^2, marsh reduced by 86.00 km^2 the number of landscape patches reduced by 56, and their average area decreased by 2.68 km^2, the successions within lake, marsh, semi-marsh and grassland were found obviously. S decreased stepwise： D and F increased but H decreased： The changing rate after 1994 was 2.3 to 2.9 times greater than that before. The change of the wetland landscape patterns resulted in the interaction between socio-ceenomic and natural forces of positive and negative aspects; and natural factors

关键词： Landscape pattern driving force fragmentation marsh pasture metrics Zoige Qinghai-Tibetan Plateau

Color tunable and white light emitting via energy transfer in single-phase BiOCl:Er^(3+),Sm^(3+) phosphors for WLEDs

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Journal of Rare Earths 2018年第3期36卷 231-237页

作者： Xiangzhou Zhang Yongjin Li Rui Hu zuyuan Xu Jianbei Qiu Zhengwen Yang Zhiguo Song School of Materials Science and Engineering Kunming University of Science and Technology School of Materials Science and Engineering Sun Yat-sen University

BiOCl crystal shows potential as efficient optical host due to its special layered structure. here,the luminescence properties of the Er^3＋/Sm^3＋ co-doped BiOCl phosphors as single-phase phosphors were reported. Upon near ultraviolet excitation（NUV, 380 nm corresponding the ^4 I15/2→ ^4 G11/2 transition of Er^3＋ ions）, the phosphors exhibit the efficient characteristic emissions of Er^3＋ and Sm^3＋ ions simultaneously. The energy transfer（ET） from Er^3＋ to Sm^3＋ ions in the layered crystals has been validated by the variation of emission intensities and decay lifetimes respectively, which is ascribed to be a dipoledipole interaction. By virtue of the ET behavior and increasing Sm^3＋ ion concentration, the enhancing emission intensity of Sm^3＋ and the tunability of emission color from yellowish-green（0.318, 0.420） to white（0.343, 0.347） are realized. The results of our work indicate that the Er^3＋/Sm^3＋ co-doped BiOCI phosphor has a promising application serving as single component white emitting phosphors for NUV excited WLEDs.

关键词： BiOCl Er^3+ Sm^3+ Color tunable Photoluminescence Energy transfer

农产品区域品牌发展中的小农户参与样态及其富民效应--基于多案例比较分析

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湖湘论坛 2024年第1期37卷 64-77页

作者：赵祖远周佩萱西北农林科技大学人文社会发展学院陕西杨凌712100

农产品区域品牌建设是迈向乡村振兴,同步实现农业产业兴旺与农民生活富裕的重要举措,农产品区域品牌富民效应的发挥与小农户的参与方式密切相关。根据小农户在土地、劳动力和资本等要素的投入特征,将小农户在农产品区域品牌发展中的参... 详细信息

农产品区域品牌建设是迈向乡村振兴,同步实现农业产业兴旺与农民生活富裕的重要举措,农产品区域品牌富民效应的发挥与小农户的参与方式密切相关。根据小农户在土地、劳动力和资本等要素的投入特征,将小农户在农产品区域品牌发展中的参与样态区分为专业化参与、兼业化参与以及非经营性参与。调研发现,小农户不同参与样态下,农产品区域品牌对小农户的直接经济效益、带动规模以及带动的可持续性等均呈现较大差异。为了更好实现农产品区域品牌的富民惠农效应,应拓展小农户参与机会、提升小农户参与能力、保障小农户参与利益,不断提升小农户在农产品区域品牌建设中的参与感、获得感。

关键词：农产品区域品牌小农户参与样态产业富民

Targeting tumor microenvironment as a treatment strategy for hepatocellular carcinoma

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hepatobiliary Surgery and Nutrition 2020年第6期9卷 794-796页

作者： zuyuan Lin Xiaonan Xiang Di Lu Xiao Xu Department of hepatobiliary and Pancreatic Surgery First Affiliated HospitalZhejiang University School of MedicineHangzhouChina National Clinical Research Center for Infectious Diseases HangzhouChina

Liver cancer was ranked the sixth most commonly diagnosed cancer with the fourth leading cause of cancer-related deaths worldwide in 2018(1).Notably,hepatocellular carcinoma(HCC)constitutes 75-85%among all the liver cancer cases,and ranks first morbidity and mortality of malignancies in Chinese males under *** to hypervascularity in liver and high heterogeneity,HCC was regarded as an aggressive *** clinical trials focusing on resection and transplantation after targeted therapy for advanced HCC show encouraging ***,the adjuvant therapy for patients with high risk of recurrence after surgery still raises ***,emerging evidence suggested that the crosstalk between tumor cells and the microenvironment plays a pivotal role in tumorigenesis and metastasis.

关键词： hepatocellular mortality treatment

电火花成型电极修整航空发动机叶片的加工误差分析

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现代制造工程 2024年第3期 95-102页

作者：汪转延蔡振辉党宏伟陈达源曹利新余祖元大连理工大学机械工程学院大连116024

针对航空发动机叶片电解加工后前后缘存在较大加工误差这一问题,采用电火花加工技术对叶片前后缘进行修整,并分析前后缘的加工误差。使用自研的六轴电火花成型机床,采用成型电极对叶片后缘进行修整加工,并利用三坐标测量机完成叶片点云... 详细信息

针对航空发动机叶片电解加工后前后缘存在较大加工误差这一问题,采用电火花加工技术对叶片前后缘进行修整,并分析前后缘的加工误差。使用自研的六轴电火花成型机床,采用成型电极对叶片后缘进行修整加工,并利用三坐标测量机完成叶片点云数据的测量。采用遗传算法和迭代最近点算法,完成包络加工后叶片点云数据与理论模型的配准,通过最小二乘椭圆以及NURBS曲线拟合处理点云数据。针对拟合的叶片加工后轮廓曲线,通过在该曲线上等间距取点并计算这些点到叶片理论轮廓线的距离来反映叶片后缘的加工误差和加工误差的整体趋势。结果显示:经过电火花成型电极修整后叶片后缘的面轮廓度误差在-16.4~88.5μm之间,平均误差为53.7μm,叶片后缘的缘头处轮廓度误差最小,验证了电火花加工技术包络修整叶片前后缘的可行性。

关键词：航空发动机叶片前后缘电火花加工点云数据 NURBS 加工误差分析

Nyström-based spectral clustering using airborne LiDAR point cloud data for individual tree segmentation

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International Journal of Digital Earth 2021年第10期14卷 1452-1476页

作者： Yong Pang Weiwei Wang Liming Du Zhongjun Zhang Xiaojun Liang Yongning Li zuyuan Wang Institute of Forest Resource Information Techniques Chinese Academy of ForestryBeijingPeople’s Republic of China Key Laboratory of Forestry Remote Sensing and Information System of National Forestry and Grassland Administration BeijingPeople’s Republic of China College of Artificial Intelligence Beijing Normal UniversityBeijingPeople’s Republic of China College of Forestry Hebei Agricultural UniversityBaodingPeople’s Republic of China Department of Land Change Science Swiss Federal Institute for ForestSnow and Landscape Research WSLBirmensdorfSwitzerland

The spectral clustering method has notable advantages in *** the high computational complexity and time consuming limit its application in large-scale and dense airborne Light Detection and Ranging(LiDAR)point cloud *** proposed the Nyström-based spectral clustering(NSC)algorithm to decrease the computational *** novel NSC method showed accurate and rapid in individual tree segmentation using point cloud *** K-nearest neighbour-based sampling(KNNS)was proposed for the Nyström approximation of voxels to improve the *** NSC algorithm showed good performance for 32 plots in China and *** overall matching rate and extraction rate of proposed algorithm reached 69%and 103%.For all trees located by Global Navigation Satellite System(GNSS)calibrated tape-measures,the tree height regression of the matching results showed an value of 0.88 and a relative root mean square error(RMSE)of 5.97%.For all trees located by GNSS calibrated total-station measures,the values were 0.89 and 4.49%.The method also showed good performance in a benchmark dataset with an improvement of 7%for the average matching *** results demonstrate that the proposed NSC algorithm provides an accurate individual tree segmentation and parameter estimation using airborne LiDAR point cloud data.

关键词： Tree segmentation airborne LiDAR spectral clustering Nyström approximation sampling method

Estimation of underdetermined mixing matrix based on support vector machine

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Progress in Natural Science:Materials International 2007年第11期17卷 1363-1367页

作者： Yang zuyuan and Xie Shengli(School of Electrics & Information Engineering, South China University of Technology, Guangzhou 510641, China) School of Electrics & Information Engineering South China University of Technology Guangzhou 510641 China

In underdetermined blind source separation (BSS), a novel algorithm based on extended support vector machine (SVM) is proposed to estimate the mixing matrix in this paper, including the number of the active sources. Instead of traditional clustering algorithms, it mainly takes the modulus of observations and the number in each direction of arrival, without any prior knowledge about the sources except for sparsity, and it is not sensitive to the initial values. Simulations are given to illustrate availability and robustness of our algorithm.

关键词： underdetermined BSS SVM clustering

冷轧变形程度对316L不锈钢硬度和强度比例关系的影响

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热加工工艺 2024年第1期53卷 111-114页

作者：顾彩云唐金丽李建生王晓震徐组缘毛庆忠赵禹安徽工程大学材料科学与工程学院安徽芜湖241000 安徽工程大学高性能有色金属材料安徽省重点实验室安徽芜湖241000 南京理工大学材料科学与工程学院江苏南京210094 安徽鑫科新材料股份有限公司安徽芜湖241006 东睦新材料集团股份有限公司浙江宁波315000

采用两辊轧机对粗晶态316L不锈钢进行不同变形程度的轧制,研究不同冷变形程度对316L不锈钢硬度-屈服强度比例关系的影响。结果显示:随着冷轧变形程度的增加,材料中出现大量的位错、变形孪晶等形变缺陷,同时,马氏体相含量也增加。随着变... 详细信息

采用两辊轧机对粗晶态316L不锈钢进行不同变形程度的轧制,研究不同冷变形程度对316L不锈钢硬度-屈服强度比例关系的影响。结果显示:随着冷轧变形程度的增加,材料中出现大量的位错、变形孪晶等形变缺陷,同时,马氏体相含量也增加。随着变形程度的增加,硬度与屈服强度的比值逐渐趋向于3,这主要是由于冷变形极大地削弱了316L不锈钢原有的加工硬化能力。

关键词：冷轧变形 316L不锈钢屈服强度硬度

STUDY OF AIRFLOW HOMOGENEITY STANDARD IN REGENERATIVE CHAMBER OF TANK FURNACE

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Journal of Wuhan University of Technology(Materials Science) 1997年第3期12卷 56-62页

作者：王玉成 Wuhan University of Technology China Ctr. for Materials Res. and Analysis Wuhan Univ. of Tech. Wuhan 430070 China

The authers compared six used criterions of influencing homogeneity of moving airflow in virtue of errors such as variance Q, average square deviation T, homogeneous indices H, inhomogeneous degree W, range R and nonuniform index S. The auther think that the effects of the errors will be magnified when all these old stnadards were calculated, especially for higher airflow homogeneity, thus the reliability of these norms would De reduced. The authers put forward two new standards to lower influence of error.

关键词： regenerative chamber airflow homogeneity standard tank furnace