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Music snippet extraction via melody-based repeated pattern discovery

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Science in China(Series F) 2009年第5期52卷 804-812页

作者： XU JiePing zhao yang chen Zhe LIU ZiLi School of Information Renmin University of China Beijing 100872 China

In this paper, we present a complete set of procedures to automatically extract a music snippet, defined as the most representative or the highlighted excerpt of a music clip. We first generate a modified and compact similarity matrix based on selected features and distance metrics, and then several improved techniques for music repeated pattern discovery are utilized because a music snippet is usually a part of the repeated melody, main theme or chorus. During the process, redundant and wrongly detected patterns are discarded, boundaries are corrected using beat information, and final clusters are also further sorted according to the occurrence frequency and energy information. Subsequently, following our methods, we designed a music snippet extraction system which allows users to detect snippets. Experiments performed on the system show the superiority of our proposed approach.

关键词： music snippet music structure beat detection tempo

Microscopic study on the key process and influence of efficient synthesis of natural gas hydrate by in situ Raman analysis of water microstructure in different systems with temperature drop

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Journal of Energy Chemistry 2023年第7期82卷 317-333,I0008页

作者： Wei Zhang Chun-Gang Xu Xiao-Sen Li Zhuo-Yi Huang zhao-yang chen School of Engineering Science University of Science and Technology of ChinaHefei 230023AnhuiChina Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640GuangdongChina CAS Key Laboratory of Gas Hydrate Guangzhou 510640GuangdongChina Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development Guangzhou 510640GuangdongChina School of Energy Science and Engineering University of Science and Technology of ChinaHefei 230023AnhuiChina

Gas hydrate technology has considerable potential in many ***,due to the lack of understanding of the micro mechanism of hydrate formation,it has not been commercially applied so *** hydrate formation is essentially a gas-liquid-solid phase transition of water and gas molecules at a certain temperature and *** key to the hydrate formation is the transformation of water molecule from disordered arrangement to ordered *** this process,weakly hydrogen bonded water will be correspondingly converted to strongly hydrogen bonded *** in situ Raman analysis and experiments,the position change of the corresponding peaks of the strongly hydrogen bonded water and the weakly hydrogen bonded water was compared in this work,and the key microscopic process and influence of gas hydrate formation in different systems were comprehensively studied and *** is found that,with the decrease of temperature,the OAH of the weakly hydrogen bonded water remains unchanged when the temperature drops to a certain value,which is the key to the transformation of water into cage hydrate rather than *** conversion from the weakly hydrogen bonded water to the strongly hydrogen bonded water is closely related to the gas-liquid interface force,the hydrophilicity/hydrophobicity of the promoter,the ionization degree of liquid,and the electrostatic field of the *** the four most common promoters,tetrahydrofuran(THF)has the highest efficiency in promoting methane(CH4)hydrate ***,this study provides a scientific direction and basis for the development of high efficient hydrate formation promoters,which can effectively weaken the hydrogen bond of weakly hydrogen bonded water and promote the conversion of weakly hydrogen bonded water to strongly hydrogen bonded water.

关键词： Hydrate Conversion Hydrogen bonded water Promoter Micro mechanism

A Novel Vision Localization Method of Automated Micro-Polishing Robot

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Journal of Bionic Engineering 2009年第1期6卷 46-54页

作者： zhao-jun yang, Fei chen, Ji zhao, Xiao-jie WuCollege of Mechanical Science and Engineering, Jilin University, Changchun 130022, P. R. China College of Mechanical Science and Engineering Jilin University Changchun P. R. China

Based on photogrammetry technology,a novel localization method of micro-polishing robot,which is restricted within certain working space,is presented in this *** the basis of pinhole camera model,a new mathematical model of vision localization of automated polishing robot is *** vision localization is based on the distance-constraints of feature *** method to solve the mathematical model is *** to the characteristics of gray image,an adaptive method of automatic threshold selection based on connected components is *** center coordinate of the feature image point is resolved by bilinear interpolation gray square weighted ***,the mathematical model of testing system is verified by global localization *** experimental results show that the vision localization system in working space has high precision.

关键词： micro-polishing robot vision localization threshold segmentation distance constraint

Damage of reservoir rock induced by CO_(2) injection

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Petroleum Science 2022年第4期19卷 1674-1681页

作者： Jing Li zhao-yang chen Yong-Cun Feng Li-Sha Qu Jia-Geng Liu Wen-Yan Li Meng-Ying Dai College of Pipeline and Civil Engineering China University of PetroleumQingdao266580ShandongChina College of Petroleum Engineering China University of PetroleumBeijing102249China School of Geosciences China University of PetroleumQingdao266580ShandongChina Research Institute of Exploration and Development PetroChina Tarim Oilfield CompanyKorla841000XinjiangChina

The study of reservoir rock damage induced by gas injection is of great significance to the design of reservoir stimulation and the improvement of oil and gas recovery. Based on an example horizontal well in the Hudson Oilfield of the Tarim Basin and considering the multi-physics coupling effects among highpressure fluid, rock deformation, and damage propagation during CO_(2) injection, a three-dimensional finite element model for CO_(2) injection in deep reservoir considering seepage-stress-damage coupling was developed. The evolution of reservoir rock damage under different CO_(2) injection conditions was systematically investigated. The results show that tensile damage and shear damage are concentrated in the vertical direction and the horizontal maximum compressive principal stress direction, respectively,and the tensile damage is the main damage mode. At higher CO_(2) injection rate and pressure, the damaged areas near the wellbore are mainly distributed in the direction of the maximum compressive principal stress, and the development of the damaged area near the wellbore will be inhibited by the formation and evolution of far-field damage. CO_(2) injection aggravates the extension of tensile damage,but inhibits the initiation of shear damage, and eventually leads to the gradual transition from shear damage to tensile damage. Under the same injection conditions, CO_(2) injection has superior performance in creating rock damage compared with the injection of nitrogen and water. The results in this study provide guidance for enhanced oil recovery in deep oil and gas reservoirs with CO_(2) injection.

关键词： CO_(2)injection Seepage-stress-damage coupling Rock damage Numerical simulation

Effect of Helicobacterpyloriinfection on gastric mucosal pathologic change and level of nitric oxide and nitric oxide synthase

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World Journal of Gastroenterology 2005年第32期11卷 5029-5031页

作者： Yong-Fu Wang Chun-Lin Guo Li-Zhen zhao Guo-An yang Peng chen Hong-Kun Wang First Hospital Baotou Medical College University of Science and Technology of Inner Mongolia Baotou 014010 Inner Mongolia China

AIM： To investigate the level of nitric oxide （NO） and nitrous oxide synthase （NOS） enzyme and its effect on gastric mucosal pathologic change in patients infected with Helicobacter pylori （H pylori）, and to study the pathogenic mechanism of H pylori. METHODS： The mucosal tissues of gastric antrum were taken by endoscopy, then their pathology, H pylori and anti-CagA-IgG were determined. Fifty H pylori positive cases and 35 H pylori negative cases were randomly chosen. Serum level of NO and NOS was detected. RESULTS： One hundred and seven cases （71.33%） were anti-CagA-IgG positive in 150 H pyloripositive cases. The positive rate was higher especially in those with preneoplastic diseases, such as atrophy, intestinal metaplasia and dysplasia. The level of NO and NOS in positive group was higher than that in negative group, and apparently lower in active gastritis than in pre-neoplastic diseases such as atrophy, intestinal metaplasia and dysplasia. CONCLUSION： H pylori is closely related with chronic gastric diseases, and type I H pylori may be the real factor for H pylori-related gastric diseases. Infection with H pylori can induce elevation of NOS, which produces NO.

关键词： Helicobacter pylorr Nitric oxide Nitric oxide synthase Gastric mucosa Pathology

Gapless genome assembly of azalea and multi-omics investigation into divergence between two species with distinct f lower color

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Horticulture Research 2023年第1期10卷 193-206页

作者： Shuai Nie Shi-Wei zhao Tian-Le Shi Wei zhao Ren-Gang Zhang Xue-Chan Tian Jing-Fang Guo Xue-Mei Yan Yu-Tao Bao Zhi-Chao Li Lei Kong Hai-Yao Ma zhao-yang chen Hui Liu Yousry AEl-Kassaby Ilga Porth Fu-Sheng yang Jian-Feng Mao National Engineering Research Center of Tree Breeding and Ecological Restoration Beijing Advanced Innovation Center for Tree Breeding by Molecular DesignKey Laboratory of Genetics and Breeding in Forest Trees and Ornamental PlantsMinistry of EducationCollege of Biological Sciences and TechnologyBeijing Forestry UniversityBeijing 100083China Department of Ecology and Environmental Science UmeåPlant Science CentreUmeåUniversitySE-90187 UmeåSweden Department of Bioinformatics Ori(Shandong)Gene Science and Technology Co.Ltd.Weifang 261322China Department of Forest and Conservation Sciences Faculty of ForestryUniversity of British ColumbiaVancouverBCV6T 1Z4Canada Départment des Sciences du Bois et de la Forêt Facultéde Foresteriede Géographie et GéomatiqueUniversitéLavalQuébecQCG1V 0A6Canada State Key Laboratory of Systematic and Evolutionary Botany Institute of BotanyChinese Academy of SciencesBeijing 100093China University of Chinese Academy of Sciences Beijing 100049China

The genus Rhododendron(Ericaceae),with more than 1000 species highly diverse in f lower color,is providing distinct ornamental values and a model system for f lower color ***,we investigated the divergence between two parental species with different f lower color widely used for azalea *** genome assembly was generated for the yellow-f lowered azalea,Rhododendron *** genomics found recent proliferation of long terminal repeat retrotransposons(LTR-RTs),especially Gypsy,has resulted in a 125 Mb(19%)genome size increase in species-specific regions,and a significant amount of dispersed gene duplicates(13402)and pseudogenes(17437).Metabolomic assessment revealed that yellow f lower coloration is attributed to the dynamic changes of carotenoids/f lavonols biosynthesis and chlorophyll ***-ordered gene co-expression networks(TO-GCNs)and the comparison confirmed the metabolome and uncovered the specific gene regulatory changes underpinning the distinct f lower pigmentation.B3 and ERF TFs were found dominating the gene regulation of carotenoids/f lavonols characterized pigmentation in ***,while WRKY,ERF,WD40,C2H2,and NAC TFs collectively regulated the anthocyanins characterized pigmentation in the red-f lowered R *** study employed a multi-omics strategy in disentangling the complex divergence between two important azaleas and provided references for further functional genetics and molecular breeding.

关键词： divergence yellow collective

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PVC/PMMA合金微滤膜的研制

中国塑料 2001年第2期15卷 46-49页

作者：赵晨阳孙本惠北京化工大学材料科学与工程学院北京100029

以PVC/PMMA合金为膜材料 ,研制出了具有非对称断面结构的微滤膜。经优化后膜的平均孔径为 0 .18-9.2 8μm ,在 0 .1MPa操作压力下膜的纯水通量可高达 2 2 0 0 0L/m2 ·h。对影响膜结构与性能的若干因素也进行了探讨。

关键词：微滤膜高分子合金相容性聚氯乙烯 PMMA

高固含量乳液(St/BA/AA)的合成、乳胶粒径及其分布

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高分子材料科学与工程 2005年第2期21卷 118-120,124页

作者：赵晨阳李效玉北京化工大学材料科学与工程学院北京100029

采用滴加预乳化液的半连续乳液聚合方法,合成了固含量高达65%的苯乙烯/丙烯酸丁酯/丙烯酸(St/BA/AA)共聚物乳液,并系统研究了乳化剂含量、固含量、单体配比、功能单体浓度对乳胶粒大小及分布的影响,利用透射电子显微镜对乳胶粒子的微观... 详细信息

采用滴加预乳化液的半连续乳液聚合方法,合成了固含量高达65%的苯乙烯/丙烯酸丁酯/丙烯酸(St/BA/AA)共聚物乳液,并系统研究了乳化剂含量、固含量、单体配比、功能单体浓度对乳胶粒大小及分布的影响,利用透射电子显微镜对乳胶粒子的微观形态进行了表征。结果表明,乳化剂及功能单体浓度增加,乳胶粒粒径减小,分布变窄;增加固含量、单体BA用量,乳胶粒径增大,分布加宽。高固含量(St/BA/AA)乳液的平均粒径在150nm～500nm范围内,粒径分散系数为1.06～2.5,乳胶粒子呈多分散分布。

关键词：乳液聚合高固含量粒径分布

Role of the Greenland Sea ice anomaly in the late-spring drought over Northwest China

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 1-5页

作者： yang Liu Huopo chen Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of SciencesBeijingChina Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University for Information Science and TechnologyNanjingChina

Drought across Northwest China in late spring has exerted a vital effect on the local climate and agricultural production,and has been alleviated during the past *** study explored the influence of the preceding Arctic sea ice on the May drought in Northwest China caused by the precipitation *** analysis indicated that when the Greenland Sea ice concentration is abnormally high during February to April,the dry conditions in Northwest China tend to be *** increase of sea ice in the Greenland Sea can excite a meridional circulation,which causes sea surface temperature(SST)anomalies in the North Atlantic via the sea-air interaction,manifested as significant warm SST anomalies over the south of Greenland and the subtropical North Atlantic,but negative SST anomalies over the west of the *** abnormal SST pattern maintains to May and triggers a zonal wave train from the North Atlantic through Scandinavia and Central Asia to Northwest China,leading to abnormal cyclones in Northwest ***,Northwest China experiences a more humid climate than usual.

关键词： Arctic sea ice Greenland Sea North Atlantic SST Drought Northwest China