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Analysis on Chemical Compositions in Chinese Wolfberry from Different Producing Areas 被引量:4
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作者 董海峰 任永丽 《Agricultural Science & Technology》 CAS 2012年第9期1870-1872,共3页
[Objective] This study aimed to conduct correspondence cluster analysis of the trace elements in Chinese wolfberry from Qinghai and Ningxia regions, and to investigate the relationship among the quality of the wolfber... [Objective] This study aimed to conduct correspondence cluster analysis of the trace elements in Chinese wolfberry from Qinghai and Ningxia regions, and to investigate the relationship among the quality of the wolfberry samples, the composition of trace elements and the sample sources. [Method] The determined contents of trace elements and ratios of zinc to copper (Zn/Cu) of wolfberry from 11 different producing areas of Qinghai and Ningxia regions were adopted to construct the raw measurement data matrix, to analyze the distribution characteristics of the trace ele- ments in wolfberry from Qinghai and Ningxia by using the corresponding cluster analysis method. [Result] The quality of wolfberry samples in 7hongning County, Zhongwei City, Pingluo County, Shizuishan City, Heicheng Town of Ningxia Hui Au-tonomous Region and Hehuang Valley, Golmud City of Qinghai Province is mainly related to the contents of Zn and Mn; Zn/Cu greatly affects the quality of Chinese wolfberry in Dulan County of Qinghai Province; Fe has great effect on the quality of Chinese wolfberry in Yinchuan City of Ningxia Hui Autonomous Region; Cu greatly affects the quality of Chinese wolfberry in Nuomuhong Village of Qinghai Province and a wolfberry research institute in Ningxia. [Conclusion] The relationship between the quality of wolfberry from different producing areas and the trace elements was investigated, which provides theoretical and practical basis for the cultivation, har- vesting, processing, and further development and utilization of Chinese wolfberry resources from different producing areas. 展开更多
关键词 Chinese wolfberry Correspondence cluster analysis Trace elements
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CORRESPONDENCE ANALYSIS ON IMAGES OF JIANGXI PROVINCE AS A TOURIST DESTINATION 被引量:10
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作者 MAO Duan-qian ZHANG Jie BAO Hao-sheng 《Chinese Geographical Science》 SCIE CSCD 2005年第3期275-280,共6页
This paper delineates the images of Jiangxi Province as tourist destination perceived by about 2000 sample visitors at Lushan Mountain and other 3 famous resorts (Jinggangshan Mountains, Longhushan Mountain, and Sanqi... This paper delineates the images of Jiangxi Province as tourist destination perceived by about 2000 sample visitors at Lushan Mountain and other 3 famous resorts (Jinggangshan Mountains, Longhushan Mountain, and Sanqingshan Mountain), with a result that the most common image is the famous scenic mountain image with partial attribute of image of religious culture destination. In order to reveal the similarities and dissimilarities of images among the four destinations, a correspondence analysis on 16 image attributes was employed. The results indicate that the tourists’ images on Longhushan Mountain, Sanqingshan Mountain and Lushan Mountain are very similar: having a lot of good tourist sites, famous mountain scenery, being close to nature and having good guide service, and others, but religious culture and good shopping facilities having not made deep impression on tourist, while Jinggangshan Mountains is famous for its red culture. The correspondence analysis visualizes the strengths and weaknesses of the destinations, which is useful for market positioning among the competitive places. Finally, some marketing suggestions for the four destinations were provided. 展开更多
关键词 tourist destination IMAGE cognitive attribute evaluative attribute correspondence analysis
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Study on the Characteristics of Urban Air Pollution Based on Correspondence Analysis--A Case Study of Six Provincial Capitals in Central-south China 被引量:5
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作者 WU Xu-xian PENG Xin-yu 《Meteorological and Environmental Research》 CAS 2011年第8期86-88,共3页
[Objective] The aim was to study the characteristics of urban air pollution on the basis of correspondence analysis.[Method] By using the correlated data from China Statistical Yearbook in 2010,a correspondence analys... [Objective] The aim was to study the characteristics of urban air pollution on the basis of correspondence analysis.[Method] By using the correlated data from China Statistical Yearbook in 2010,a correspondence analysis on the air pollution indicators(like respirable particles,SO2 and NO2) of six provincial capitals in central-south China was carried out by means of SPSS software,and the characteristics of air pollution in the cities of China during different industrialization stages were summarized further.[Result] In the cities during early industrialization(like Nanning City and Guiyang City) and mineral resource-based cities(like Taiyuan City),the air was mainly polluted by SO2;for the cities in the middle industrialization(such as Changsha City,Wuhan City,Zhengzhou City and Chengdu City),the air was polluted by respirable particles chiefly;in the cities in late industrialization(like Guangzhou City and Shenzhen City) or completing industrialization(like Shanghai City),the air was mainly polluted by NO2;for the cities in pre-industrial stage(like Haikou City and Lhasa City),the characteristic of air pollution wasn’t obvious.[Conclusion] The study could provide references for the control of urban air pollution in China in the further. 展开更多
关键词 Correspondence analysis Air pollution Central-south China Provincial capitals China
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Analysis of Synonymous Codon Usage Bias in 09H1N1 被引量:3
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作者 Zhen-peng LI De-quan YING Peng LI Fei LI Xiao-chen BO Sheng-qi WANG 《Virologica Sinica》 SCIE CAS CSCD 2010年第5期329-340,共12页
A novel subtype of influenza A virus 09H1N1 has rapidly spread across the world. Evolutionary analyses of this virus have revealed that 09H1N1 is a triple reassortant of segments from swine, avian and human influenza ... A novel subtype of influenza A virus 09H1N1 has rapidly spread across the world. Evolutionary analyses of this virus have revealed that 09H1N1 is a triple reassortant of segments from swine, avian and human influenza viruses. In this study, we investigated factors shaping the codon usage bias of 09H1N1 and carried out cluster analysis of 60 strains of influenza A virus from different subtypes based on their codon usage bias. We discovered that more preferentially used codons of 09H1N1 are A-ended or U-ended, and the intra-genomic codon usage bias of 09H1N1 is quite low. Base composition constraint, dinucleotide biases and translational selection are the main factors influencing the codon usage bias of 09H1N1. At the genome level, we find that the codon usage bias of 09H1N1 is similar to H1N1 (A/swine/Kansas/77778/2007H1N1), H9N2 from Asia, H1N2 from Asia and North America and H3N2 from North America. Our results provide insight for understanding the processes governing evolution, regulation of gene expression, and revealing the evolution of 09H1N1. 展开更多
关键词 09H1N1 Correspondence analysis Codon usage bias
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Applied research of correspondence analysis method in waste tailings reservoir heavy metal pollution monitoring points optimization
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作者 WANG Cong-lu WU Chao +1 位作者 LI Zi-jun XUE Sheng-guo 《Journal of Coal Science & Engineering(China)》 2010年第4期419-423,共5页
In order to optimize monitoring points and monitoring factor, the relationshipbetween pollutants and soil sample were established by correspondence analysis.Thestudy results show that the reflecting monitoring points ... In order to optimize monitoring points and monitoring factor, the relationshipbetween pollutants and soil sample were established by correspondence analysis.Thestudy results show that the reflecting monitoring points and monitoring factors in thegraphic on the same factor axis can clearly express the intrinsic link between pollutantsand monitoring points and distribution characteristics.To determine the main monitoringpoint and the main monitoring indicators can reduce and optimize the number of monitoringpoints under the premise of ensuring the typical and representative of monitoring data.Using the correlation of pollutants can reduce the number of monitoring indicators and improvethe effectiveness of data collection. 展开更多
关键词 tailings reservoir heavy metal pollution in-situ monitoring correspondence analysis method OPTIMIZATION
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Rules of Pesticide Use for Food Crop Diseases and Pests: A Concise Diagram Based on Correspondence Analysis
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作者 Xiaojie YANG Shaohua ZHANG +2 位作者 Weizheng LI Huaisen XING Guohui YUAN 《Agricultural Biotechnology》 CAS 2022年第5期57-64,71,共9页
In order to ensure food security, the selection of pesticide must take into account the controlling effect and economy in the chemical control of food crop diseases and pests. Although China has registered a large num... In order to ensure food security, the selection of pesticide must take into account the controlling effect and economy in the chemical control of food crop diseases and pests. Although China has registered a large number of pesticides and fungicides on food crops, traditional statistical methods cannot treat the complex relationships between crops, pests and diseases, as well as pesticides. To this end, the correspondence analysis was used to mine the data of pesticides being registered after January 1, 2010 for the prevention and control of pests and diseases on wheat, corn, and rice in China, in order to reveal the general rules of pesticide use for the prevention and control of grain crop pests and diseases and to provide scientifically recommended pesticide regimens.(1) Recommended pesticides for wheat diseases and pests: For underground pest control, phoxim, diazinon or clothianidin is recommended;imidacloprid is recommended for aphid control;avermectin is recommended for mite control;chlorpyrifos is recommended for midge control;the pesticides for rust control could be selected according to the order of epoxiconazole>flutriafol>kresoxim-methyl>cyproconazole≈hexaconazole;tebuconazole is recommended for the prevention and control of smut;difenoconazole is recommended for the simultaneous occurrence of take-all, smut and sheath blight;it is recommended to use carbendazim or thiophanate-methyl for the control of scab;and triazolone or pyraclostrobin is recommended for the control of powdery mildew.(2) Recommended pesticides for corn diseases and pests: For the control of underground pests, fipronil, carbosulfan or chlorpyrifos are recommended;thiamethoxam is recommended for control of planthoppers and corn aphids;Bacillus thuringiensis or phoxim is recommended for control of corn borers;pyraclostrobin is recommended for the control of northern leaf blight;tebuconazole is recommended for the control of head smut;and fludioxonil+metalaxyl-M is recommended for the control of corn stalk rot.(3) Recommended pesticides for rice diseases and pests: It is recommended to use triazophos, avermectin analogs or methoxyfenozide for the control of borers;for rice planthoppers, the pesticides could be selected in order of pymetrozine>imidacloprid>thiamethoxam>thiazide>nitenpyram;avermectin analogs are recommended for the control of rice leaf rollers;tebuconazole is recommended for the control of rice false smut;prochloraz and its manganese salts are recommended for the control of bakanae disease;hymexazol is recommended for the control of wilt disease;thifluzamide or hexaconazole is recommended for the control of sheath blight;and the pesticides for the control of rice blast are in order of tricyclazole>kasugamycin>fenoxanil>isoprothiolane>Bacillus subtilis. In addition, potential applications of correspondence analysis in other fields of plant protection are discussed. 展开更多
关键词 Food crop Wheat CORN Rice FUNGICIDE PESTICIDE Correspondence analysis Pesticide use rules
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Classification of subtypes of patients with eating disorders by correspondence analysis
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作者 Josune Martín Ane Anton-Ladislao +2 位作者 Ángel Padierna Belén Berjano JoséMaría Quintana 《World Journal of Psychiatry》 SCIE 2021年第7期375-387,共13页
BACKGROUND Grouping eating disorders(ED)patients into subtypes could help improve the establishment of more effective diagnostic and treatment strategies.AIM To identify clinically meaningful subgroups among subjects ... BACKGROUND Grouping eating disorders(ED)patients into subtypes could help improve the establishment of more effective diagnostic and treatment strategies.AIM To identify clinically meaningful subgroups among subjects with ED using multiple correspondence analysis(MCA).METHODS A prospective cohort study was conducted of all outpatients diagnosed for an ED at an Eating Disorders Outpatient Clinic to characterize groups of patients with ED into subtypes according to sociodemographic and psychosocial impairment data,and to validate the results using several illustrative variables.In all,176(72.13%)patients completed five questionnaires(clinical impairment assessment,eating attitudes test-12,ED-short form health-related quality of life,metacognitions questionnaire,Penn State Worry Questionnaire)and sociodemographic data.ED patient groups were defined using MCA and cluster analysis.Results were validated using key outcomes of subtypes of ED.RESULTS Four ED subgroups were identified based on the sociodemographic and psychosocial impairment data.CONCLUSION ED patients were differentiated into well-defined outcome groups according to specific clusters of compensating behaviours. 展开更多
关键词 Multiple correspondence analysis Eating disorders Compensating behaviour Observational descriptive study
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Canonical Correspondence Analysis of Phytoplankton Community and Environmental Factors in Genhe River
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作者 Zhenjiang WANG Hongxian YU 《Asian Agricultural Research》 2017年第9期24-27,共4页
To understand the status of phytoplankton community of the Genhe River in the summer of 2015,we investigated the phytoplankton in Genhe River. We identified 5 phyla and 36 species,among which Bacillariophyta(23) were ... To understand the status of phytoplankton community of the Genhe River in the summer of 2015,we investigated the phytoplankton in Genhe River. We identified 5 phyla and 36 species,among which Bacillariophyta(23) were the most,followed by Chlorophyta(10),Cyanophyta(1),Chrysophyta(1),Pyrrophyta(1). The phytoplankton abundance was(15. 6-810) × 104 ind·L^(-1); the biomass was(0. 07-2. 876) mg·L-1; Shannon-wiener index was 1. 05-3. 24; Pielou evenness index was 0. 27-0. 96. Using Shannon-wiener index and Pielou index,the water quality of Genhe River was assessed,and the results showed that the water quality was the best at 5# sampling point,the water quality was good in 3#,4#,7#,8#,9# sampling points,and there was a state of pollution at other sampling points. Canonical correspondence analysis and Pearson correlation analysis showed that iron ion,transparency,p H value,water depth and water temperature were important environmental factors that affect the distribution of phytoplankton,and copper ion,nitrite ion and COD also significantly affected the distribution of phytoplankton. 展开更多
关键词 PHYTOPLANKTON Canonical correspondence analysis Community structure
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Elaboration of Explanatory Factors of Accidents in Cameroon by Factorial Correspondence Analysis
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作者 Simon Armand Zogo Tsala Cyrille Onomo +1 位作者 Gregory Mvogo Louis Max Ayina Ohandja 《Journal of Transportation Technologies》 2020年第3期280-290,共11页
The aim of this paper is to examine the causes of road accidents in Cameroon. The Douala-Yaoundé highway was chosen as the case of study. Available field data recorded from the year 2006 to 2011, have enabled the... The aim of this paper is to examine the causes of road accidents in Cameroon. The Douala-Yaoundé highway was chosen as the case of study. Available field data recorded from the year 2006 to 2011, have enabled the analysis of each accident. The method used here is the factorial correspondence analysis;which aims to bring in a small number of dimensions, most of the initial </span><span style="font-family:Verdana;">information, focusing not on the absolute values, but the correspondence between t</span><span style="font-family:Verdana;">he variables, that is to say the relative values. From this analysis, it appears that, of the 906 accidents recorded during this period, top five causes account for nearly 83% of the information provided by the set of variables on the occurrence of road accidents. These causes are: driver inattention, lack of control, over speeding, improper overtaking and tire puncture. These results </span><span style="font-family:Verdana;">require involvement in the construction of road safety policies through training,</span><span style="font-family:Verdana;"> sensitization and adequate repressions as well as administrative reforms and research policy in road safety. 展开更多
关键词 Road Accident Road Safety Factorial Correspondence analysis Accidental Variables Accidents Explanatory Factors
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Using Multiple Correspondence Analysis to Measure Multidimensional Poverty in Congo
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作者 Samuel Ambapour 《Journal of Data Analysis and Information Processing》 2020年第4期241-266,共26页
The following analysis is based on a multidimensional understanding of poverty using a nonmonetary basic needs approach. It is ground on data from the first survey on household living conditions for poverty assessment... The following analysis is based on a multidimensional understanding of poverty using a nonmonetary basic needs approach. It is ground on data from the first survey on household living conditions for poverty assessment, conducted by the National Institute of Statistics of Congo in 2005. Multiple Correspondence Analysis is applied to construct a composite indicator by aggregating several attributes likely to reflect the poverty of individuals or households. The application shows that Congolese households are not affected by the same type of poverty. Three types of non-monetary poverty are identified: infrastructure poverty, vulnerability of human existence and poverty of comfort. These households were then classified according to the composite indicator of Poverty. The results show that the incidence of poverty corresponds to the weight of poor class of about 70.67%. 展开更多
关键词 Multiple Correspondence analysis Basic Needs Composite Indicator of Multidimensional Poverty
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Subset Multiple Correspondence Analysis as a Tool for Visualizing Affiliation Networks
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作者 Achilles Dramalidis Angelos Markos 《Journal of Data Analysis and Information Processing》 2016年第2期81-89,共9页
In this paper we investigate the potential of Subset Multiple Correspondence Analysis (s-MCA), a variant of MCA, to visually explore two-mode networks. We discuss how s-MCA can be useful to focus the analysis on inter... In this paper we investigate the potential of Subset Multiple Correspondence Analysis (s-MCA), a variant of MCA, to visually explore two-mode networks. We discuss how s-MCA can be useful to focus the analysis on interesting subsets of events in an affiliation network while preserving the properties of the analysis of the complete network. This unique characteristic of the method is also particularly relevant to address the problem of missing data, where it can be used to partial out their influence and reveal the more substantive relational patterns. Similar to ordinary MCA, s- MCA can also alleviate the problem of overcrowded visualizations and can effectively identify associations between observed relational patterns and exogenous variables. All of these properties are illustrated on a student course-taking affiliation network. 展开更多
关键词 Affiliation Networks Two-Mode Networks Subset Correspondence analysis
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Interpretation of Water Samples by Correspondence Analysis for Radioactive Elements in the Northern Coast of Oman Sea
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作者 Farshad Darabi-Golestan Mohamad Reza Zare 《Journal of Metallic Material Research》 2022年第1期25-31,共7页
Oman Sea is connecting belt between the Indian Ocean and Persian Gulf.Because it strategic and environmental aim,presence of natural radionuclide ^(226)Ra,^(232)Th,^(40)K and ^(137)Cs as man-made element is considered... Oman Sea is connecting belt between the Indian Ocean and Persian Gulf.Because it strategic and environmental aim,presence of natural radionuclide ^(226)Ra,^(232)Th,^(40)K and ^(137)Cs as man-made element is considered.Water samples were taken from 36 marine spots at the coastal strip from Hormoz canyon to Goatr seaport in the northern coast of Oman Sea.Correspondence analysis is used to identify variation and relationship between samples(Q-mood analysis)and variable(R-mood analysis)based on approximate χ^(2)distances.Radioactive elements(^(226)Ra,^(232)Th and^( 40)K),physical(temperature,pH,turbidity,conductivity,special density)and chemical(salinity,oxygen and chlorophyll)parameters of water for 36 samples handled by correspondence analysis,there are two outstanding result,(1)Radioactive elements show high correlation in factors by greater eigenvalue,and (2)some of the samples such as W13,W24 and rather W02,W05 and W12 show highest activity from Radioactive elements and also temperature and conductivity show nearest relation with them in many factors. 展开更多
关键词 Hormoz canyon R-mood analysis Correspondence analysis Radioactive elements Marine spot samples
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Evaluation of Soil Fertility Quality and Environmental Driving Factors in Different Soil Types of Artificial Forests
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作者 Songyu YU Zhenhui LIAO +3 位作者 Mingwu YANG Ronghui HU Yuanyuan SHI Junyu ZHAO 《Meteorological and Environmental Research》 2024年第2期64-70,共7页
The aim was to clarify the environmental driving factors of soil fertility indicators in artificial forests of Guangxi and comprehensively evaluate the soil fertility level.By collecting data on the current status of ... The aim was to clarify the environmental driving factors of soil fertility indicators in artificial forests of Guangxi and comprehensively evaluate the soil fertility level.By collecting data on the current status of soil in artificial forests,the spatial distribution of major soil fertility indicators was analyzed,and the distribution map of the fertility index of artificial forests in the entire region and the comprehensive fertility index of artificial forests of different soil types were obtained.Canonical correspondence analysis method was used to analyze soil fertility indicators and environmental factors,and the environmental driving factors of soil fertility indicators for artificial forests of the main soil types in Guangxi were obtained.The results showed that over 90%of the soil fertility index of artificial forests in the entire region was between 0.20 and 0.50.The order of soil fertility index of different soil types of artificial forests from high to low was yellow brown soil>yellow red soil>yellow soil>red soil>limestone soil>latosolic red soil>laterite.In artificial forests of latosolic red soil,the correlation between soil alkaline nitrogen and organic matter,annual average temperature was high,while the correlation between soil available phosphorus and organic matter,pH was high,and the correlation between soil available potassium and environmental factors such as slope,altitude,rainfall,accumulated temperature,and slope aspect was high.In artificial forests of red soil,the correlation between soil alkaline nitrogen and slope,altitude was high,while the correlation between soil available phosphorus and accumulated temperature,rainfall was high,and the correlation between soil available potassium and pH was high.In artificial forests of limestone soil,there was a high correlation between soil alkaline nitrogen and slope,organic matter,a high correlation between soil available phosphorus and accumulated temperature,rainfall,and a high correlation between soil available potassium and pH. 展开更多
关键词 Soil fertility index GIS Forest soil Canonical correspondence analysis
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The Factors Shaping Synonymous Codon Usage in the Genome of Burkholderia mallei 被引量:4
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作者 赵胜 张琴 +2 位作者 陈智华 赵益新 钟金城 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第4期362-372,共11页
Burkholderia mallei is regarded as a potential biological weapon by the Centers for Disease Control and Prevention. In this study, the main factors shaping codon usage in the genome of B. mallei ATCC 23344 were firstl... Burkholderia mallei is regarded as a potential biological weapon by the Centers for Disease Control and Prevention. In this study, the main factors shaping codon usage in the genome of B. mallei ATCC 23344 were firstly reported. The results showed that the primary trend in codon usage variation in the B. mallei is due to translational selection; while compositional mutation bias is relatively the weaker influence and the hydrophobicity of each protein and gene length are only the minor influences. At the same time, 21 codons defined firstly as 'optimal codons' might provide more useful information for the expression of target genes and development of a vaccine to prevent glanders. 展开更多
关键词 Burkholderia mallei ATCC 23344 codon usage correspondence analysis
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Distribution Patterns of Ground Moss Species and Its Relationships with Environmental Factors in Changbai Mountain, Northeast China 被引量:5
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作者 郭水良 曹同 《Acta Botanica Sinica》 CSCD 2001年第6期631-643,共13页
The relationships of 42 species of ground moss with six environmental factors in 41 sites on Changbai Mountain Biosphere Reserve were analyzed. Four site groups and four groups of ground moss ecological species were i... The relationships of 42 species of ground moss with six environmental factors in 41 sites on Changbai Mountain Biosphere Reserve were analyzed. Four site groups and four groups of ground moss ecological species were identified using the method of Two-way Indicator Species Analysis (TWINSPAN). The results of Detrended Canonical. Correspondence Analysis (DCCA) showed that altitude, soil sand content, soil acidity, forest canopy coverage and soil water content are the five major environmental factors influencing the distributional patterns of the moss species. The four groups of ecological species, which correspond well with the four site groups, are projected on the species-environment biplot of DCCA. Group 1 dominated in the bogs of Larix olgensis forest, group 2 in the alpine tundra, group 3 in the dense conifer forest, and group 4 mainly in the Betula ermanii community and the Betula ermanii-Larix olgensis forest in sub-alpine respectively. 展开更多
关键词 MOSSES Changbai Mountain distribution pattern detrended canonical correspondence analysis
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STUDY ON THE SEQUENCE STRUCTURE OF SBR BY ^(13)C-NMR METHOD Ⅱ. PEAK ASSIGNMENT FOR ALIPHATIC CARBONS SPECTRA
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作者 焦书科 陈晓农 +1 位作者 胡力平 严宝珍 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1990年第1期25-35,共11页
The study on ^(13)C-NMR spectra of aliphatic carbon region of emuision-processed and solution-processed (by lithium catalyst) SBR was carried out. The assignments for more than thirty odd peaks observed experimentally... The study on ^(13)C-NMR spectra of aliphatic carbon region of emuision-processed and solution-processed (by lithium catalyst) SBR was carried out. The assignments for more than thirty odd peaks observed experimentally were made by using 'corresponding analysis' method, combined with the empirical parameters reported in literature. The peak intensifies were calculated based on BemouUian statistic assumption. 展开更多
关键词 corresponding analysis method peak assignment for aliphatic carbon region sequence distribution of SBR empirical parameter method.
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Seasonal variation of Microcystis in Lake Taihu and its relationships with environmental factors 被引量:16
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作者 TAN Xiao KONG Fanxiang +3 位作者 ZENG Qingfei CAO Huansheng QIAN Shanqin ZHANG Min 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第7期892-899,共8页
In order to monitor the changes of Microcystis along with temporal and spatial variations, seasonal variation of Microcystis in Lake Taihu was investigated by 16S-23S rRNA internal transcribed spacer denaturing gradie... In order to monitor the changes of Microcystis along with temporal and spatial variations, seasonal variation of Microcystis in Lake Taihu was investigated by 16S-23S rRNA internal transcribed spacer denaturing gradient gel electrophoresis (16S-23S rRNA-ITS DGGE) and microscopic evaluation. Samples were collected quarterly at four sites (River Mouth, Meiliang Bay, Cross Area, and Lake Center) from August 2006 to April 2007. Results showed that Microcystis dominated total phytoplankton abundance at the four sites in all seasons except winter. The average annual abundance of Microcystis was relatively high at River Mouth and Meiliang Bay, reaching 81.22×10^6 and 61.32×10^6 cells/L, respectively. For temporal variations, Shannon-Wiener diversity index (H') according to DGGE profile revealed the richness of Microcystis in summer (H' = 1.375±0.034) and winter (H' = 1.650 ±0.032) was lower than that in spring (H' = 2.078 ±0.031) and autumn (H' = 2.365 ±0.032) (P 〈 0.05). While for spatial variations, the richness of Microcystis at River Mouth (H' = 2.015± 0.074) was higher than at other sites during four seasons (P 〈 0.01). Very few differences of Microcystis diversity in the same season were observed among the other three sites (P 〉 0.05). Canonical correspondence analysis (CCA) was performed to elucidate the relationships between Microcystis operational taxonomic units (OTUs) composition and the environmental factors. Results of CCA revealed that temperature was strongly positively correlated with the first axis (r = 0.963), while TSS was negative correlated with the second axis (r = -0.716). Phylogenetic tree based on the sequencing results of target bands on DGGE gel indicated that samples collected in summer and winter constituted two separated clusters. 展开更多
关键词 Lake Taihu BLOOMS MICROCYSTIS rRNA-ITS DGGE canonical correspondence analysis
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Bacterial diversity and community structure in the East China Sea by 454 sequencing of the 16S rRNA gene 被引量:8
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作者 董逸 赵苑 +7 位作者 张文燕 李艳 周锋 刘诚刚 吴莹 刘素美 张武昌 肖天 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第3期527-541,共15页
The 454 sequencing method was used to detect bacterial diversity and community structure in the East China Sea. Overall, 149 067 optimized reads with an average length of 454 nucleotides were obtained from 17 seawater... The 454 sequencing method was used to detect bacterial diversity and community structure in the East China Sea. Overall, 149 067 optimized reads with an average length of 454 nucleotides were obtained from 17 seawater samples and fi ve sediment samples sourced in May 2011. A total of 22 phyla, 34 classes, 74 orders, 146 families, and 333 genera were identifi ed in this study. Some of them were detected for the fi rst time from the East China Sea. The estimated richness and diversity indices were both higher in the sediment samples compared with in the seawater samples. All the samples were divided by their diversity indices into four regions. Similarity analysis showed that the seawater samples could be classifi ed into six groups. The groups differed from each other and had unique community structure characteristics. It was found that different water masses in the sampling areas may have had some infl uence on the bacterial community structure. A canonical correspondence analysis revealed that seawater samples in different areas and at different depths were affected by different environmental parameters. This study will lay the foundation for future research on microbiology in the East China Sea. 展开更多
关键词 bacterial diversity community structure 454 sequencing water masses canonical correspondence analysis East China Sea
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Vegetation-environment Relationships Between Northern Slope of Karlik Mountain and Naomaohu Basin,East Tianshan Mountains 被引量:8
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作者 ZHANG Haiyan QIAN Yibing +1 位作者 WU Zhaoning WANG Zhongchen 《Chinese Geographical Science》 SCIE CSCD 2012年第3期288-301,共14页
Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA), this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu B... Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA), this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Ba- sin, which is situated in the easternmost end of the Tianshan Mountains, Xinjiang Uygur Autonomous Region, China. For the zonal vegetation, community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors. The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude, soil pH and soil salt content. With increasing elevation, the soil pH and total salt content decrease but the contents of soil organic matter, soil water, total nitrogen and total phosphorus increase gradu- ally. In the CCA ordination diagrams, the sample plots and main species can be divided into five types according to their adaptations to the environmental factors. Type Ⅰ is composed of desert vegetation distributed on the low moun- tains, hills, plains and deserts below an elevation of 1900 m; type Ⅱ is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m, and includes steppe desert, desert steppe and wetland meadow; type Ⅲ is very sim- ply composed of only salinized meadow; type Ⅳ is distributed above an elevation of 2300 m, containing mountain steppe, meadow steppe, subalpine meadow and alpine meadow; type Ⅴ only contains salinized meadow. The results show that with increasing elevation, species combination changes from the xerophytic shrubs, semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate. 展开更多
关键词 vegetation pattern environmental factors canonical correspondence analysis (CCA) vegetation-environment relationships Tianshan Mountains XINJIANG
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Shrub Communities and Environmental Variables Responsible for Species Distribution Patterns in an Alpine Zone of the Qilian Mountains, Northwest China 被引量:8
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作者 HUO Hong FENG Qi SU Yong-hong 《Journal of Mountain Science》 SCIE CSCD 2015年第1期166-176,共11页
Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the envir... Understanding the factors that drive variation in species distribution is a central theme of ecological research. Although several studies focused on alpine vegetation, few efforts have been made to identify the environmental factors that are responsible for the variations in species composition and richness of alpine shrublands using numerical methods. In the present study, we investigated vegetation and associated environmental variables from 45 sample plots in the middle Qilian Mountains of the northwestern China to classify different community types and to elucidate the species- environment relationships. We also estimated the relative contributions of topography and site conditions to spatial distribution patterns of the shrub communities using the variation partitioning. The results showed that four shrub community types were identified and striking differences in fioristic composition were found among them. Species composition greatly depended on elevation, slope, shrub cover, soil pH and organic carbon. The important determinants of species richness were soil bulk density and slope. No significant differences in species richness were detected among the community types. Topography and site conditions had almost equal effects on compositional variation. Nonetheless,a large amount of the variation in species composition remained unexplained. 展开更多
关键词 Alpine shrublands Floristic composition Cluster analysis Canonical Correspondence analysis(CCA) Variation partitioning Species composition Species richness
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