Industrial cluster is an aggregation of the related enterprises and institutions in certain field and in certain place. There are mainly three patterns for industrial clusters： market-oriented cluster, foreign fund o...Industrial cluster is an aggregation of the related enterprises and institutions in certain field and in certain place. There are mainly three patterns for industrial clusters： market-oriented cluster, foreign fund oriented cluster and endogenous brand oriented cluster. Many economists have established their own theories about the patterns industrial cluster, but there are few dealing with one big enterprises and its cluster pattern. This paper, taking Haier household electrical appliance as an example, is trying to study one model of Chinese industrial cluster and analyze its characteristics with their effects on economy, as.well as the advantages together with the related suggestions from the authors.展开更多
The discovery of gradual moving object clusters pattern from trajectory streams allows characterizing movement behavior in real time environment,which leverages new applications and services.Since the trajectory strea...The discovery of gradual moving object clusters pattern from trajectory streams allows characterizing movement behavior in real time environment,which leverages new applications and services.Since the trajectory streams is rapidly evolving,continuously created and cannot be stored indefinitely in memory,the existing approaches designed on static trajectory datasets are not suitable for discovering gradual moving object clusters pattern from trajectory streams.This paper proposes a novel algorithm of gradual moving object clusters pattern discovery from trajectory streams using sliding window models.By processing the trajectory data in current window,the mining algorithm can capture the trend and evolution of moving object clusters pattern.Firstly,the density peaks clustering algorithm is exploited to identify clusters of different snapshots.The stable relationship between relatively few moving objects is used to improve the clustering efficiency.Then,by intersecting clusters from different snapshots,the gradual moving object clusters pattern is updated.The relationship of clusters between adjacent snapshots and the gradual property are utilized to accelerate updating process.Finally,experiment results on two real datasets demonstrate that our algorithm is effective and efficient.展开更多
Plant photosynthetic rate is affected by stomatal status and internal CO2 carboxylation. Understanding which process determines photosynthetic rate is essential for developing strategies for breeding crops with high p...Plant photosynthetic rate is affected by stomatal status and internal CO2 carboxylation. Understanding which process determines photosynthetic rate is essential for developing strategies for breeding crops with high photosynthetic efficiency. In this study, we identified different physiological patterns of photosynthetic rate in two different rice populations. Photosynthetic gas exchange parameters were measured during the flowering stage in two rice populations. Clustering and correlation analyses were performed on the resulting data. Five or six groups were defined by K-means clustering according to differences in net photosynthetic rates(Pn). According to differences in stomatal conductance(gs) and carboxylation efficiency(CE), each group was clustered into three subgroups characterized by physiological patterns stomatal pattern, carboxylation pattern, and intermediate pattern. Pn was significantly correlated with gs(r = 0.810) and CE(r = 0.531). Pn was also significantly correlated with gs and CE in the three physiological patterns. The correlation coefficients were highest in the stomatal pattern(0.905 and 0.957) and lowest in the carboxylation pattern(0.825 and 0.859). Higher correlation coefficients between Pn and gs or CE in the three physiological patterns indicate that clustering is very important for understanding factors limiting rice photosynthesis. ? 2013 Production and hosting by Elsevier B.V. on behalf of Crop Science Society of展开更多
Purpose: To present a method for systematically mapping diversity of publication patterns at the author level in the social sciences and humanities in terms of publication type, publication language and co-authorship....Purpose: To present a method for systematically mapping diversity of publication patterns at the author level in the social sciences and humanities in terms of publication type, publication language and co-authorship.Design/methodology/approach: In a follow-up to the hard partitioning clustering by Verleysen and Weeren in 2016, we now propose the complementary use of fuzzy cluster analysis, making use of a membership coefficient to study gradual differences between publication styles among authors within a scholarly discipline. The analysis of the probability density function of the membership coefficient allows to assess the distribution of publication styles within and between disciplines.Findings: As an illustration we analyze 1,828 productive authors affiliated in Flanders, Belgium. Whereas a hard partitioning previously identified two broad publication styles, an international one vs. a domestic one, fuzzy analysis now shows gradual differences among authors. Internal diversity also varies across disciplines and can be explained by researchers’ specialization and dissemination strategies.Research limitations: The dataset used is limited to one country for the years 2000–2011; a cognitive classification of authors may yield a different result from the affiliation-based classification used here.Practical implications: Our method is applicable to other bibliometric and research evaluation contexts, especially for the social sciences and humanities in non-Anglophone countries.Originality/value: The method proposed is a novel application of cluster analysis to the field of bibliometrics. Applied to publication patterns at the author level in the social sciences and humanities, for the first time it systematically documents intra-disciplinary diversity.展开更多
Aim Cluster analysis was conducted on data from 5,169 United States （U.S.） Arizona children, age＇s 5-59-months with the goal of delineating patterns of caries in the primary dentition of pre-school children without...Aim Cluster analysis was conducted on data from 5,169 United States （U.S.） Arizona children, age＇s 5-59-months with the goal of delineating patterns of caries in the primary dentition of pre-school children without a priori pattern definitions. Methodology Cluster analyses were conducted using all data for children ages 0-4 years in aggregate： 1） for all subjects, and 2） for subjects without crowned restored teeth. Each of these two sets of analyses consisted of 8 differently specified cluster analyses as a validation procedure. Results The caries patterns identified from the clustering analysis are： 1） smooth surfaces （other than the maxillary incisor）, 2） maxillary incisor, 3） occlusal surfaces of first molars, and 4） pit and fissure surfaces of second molars. Conclusion The cluster analysis findings were consistent with results produced by multidimensional scaling. These cross-validated patterns may represent resulting disease conditions from different risks or the timing of various risk factor exposures. As such, the patterns may be useful case definitions for caries risk factor investigations in children under 60 months of age.展开更多
Patterned-based time series segmentation (PTSS) is an important task for many time series data mining applications. In this paper, according to the characteristics of PTSS, a generalized model is proposed for PTSS. Fi...Patterned-based time series segmentation (PTSS) is an important task for many time series data mining applications. In this paper, according to the characteristics of PTSS, a generalized model is proposed for PTSS. First, a new inter-pretation for PTSS is given by comparing this problem with the prototype-based clustering (PC). Then, a novel model, called clustering-inverse model (CI-model), is presented. Finally, two algorithms are presented to implement this model. Our experimental results on artificial and real-world time series demonstrate that the proposed algorithms are quite effective.展开更多
目的系统整理并归纳总结乳腺癌的中医证候分布及临床组方用药论治规律,为临床应用中医药治疗乳腺癌提供选方用药思路借鉴。方法检索建库至2024年6月30日中国知网(CNKI)、万方医学网(WANFANG MED ONLINE)、维普网(VIP)、中国生物医学服...目的系统整理并归纳总结乳腺癌的中医证候分布及临床组方用药论治规律,为临床应用中医药治疗乳腺癌提供选方用药思路借鉴。方法检索建库至2024年6月30日中国知网(CNKI)、万方医学网(WANFANG MED ONLINE)、维普网(VIP)、中国生物医学服务系统(SinoMed)文献数据库有关中医诊治乳腺癌的文献资料,建立数据库,通过Excel、SPSS Statistics、SPSS Modeler软件对证型、症状、方剂、药物进行频数统计、系统聚类和Apriori关联规则分析。结果共筛选得到文献164篇,中医证型36个,其中气血两虚、肝郁脾虚、肝郁气滞、气阴两虚、肝肾阴虚、瘀毒互结为常见证型;包含方剂257首,其中成方47首,以逍遥散、八珍汤、六君子汤为主;涉及中药281味,高频中药有白术、茯苓、甘草、黄芪、当归、柴胡、白芍、陈皮、白花蛇舌草等,功效以补虚药、清热药、活血化瘀药、理气药为主,主归肝、脾、肾经;45味高频中药系统聚类分析得到4个聚类方;关联规则分析得到20个药物组合。结论乳腺癌患者以气血两虚、肝郁脾虚、肝郁气滞证为主,在遣方用药上以益气健脾、滋阴养血为基本治法,同时辅以行气活血、清热解毒散结等药物辨证论治。展开更多
OBJECTIVE: Apply spectral clustering to analyze the patterns of symptoms in patients with chronic gastritis(CG).METHODS: Based on 919 CG subjects, we applied mutual information feature selection to choose the positive...OBJECTIVE: Apply spectral clustering to analyze the patterns of symptoms in patients with chronic gastritis(CG).METHODS: Based on 919 CG subjects, we applied mutual information feature selection to choose the positively correlated symptoms with each pattern.Then, we used the Shi and Malik spectral clustering algorithm to select the top 20 correlated symptoms.RESULTS: We ascertained the results of six patterns.There were three categories for the pattern of accumulation of damp heat in the spleen-stomach(0.00332). There were six categories for the pattern of dampness obstructing the spleen-stomach(0.02466). There were two categories for the pattern of spleen-stomach Qi deficiency(0.013 89).There were three categories for the pattern of spleen-stomach deficiency cold(0.009 15). There were five categories for the pattern of liver-Qistagnation(0.01910).There were four categories for the pattern of stagnant heat in the liver-stomach(0.00585).CONCLUSION: Most of the spectral clustering results of the symptoms of CG patterns were in accordance with clinical experience and Traditional Chinese Medicine theory. Most categories suggested the nature and/or location of the disease.展开更多
The summer day-by-day precipitation data of 97 meteorological stations on the Qinghai-Tibet Plateau from 1961 to 2004 were selected to analyze the temporal-spatial distribution through accumulated variance,correlation...The summer day-by-day precipitation data of 97 meteorological stations on the Qinghai-Tibet Plateau from 1961 to 2004 were selected to analyze the temporal-spatial distribution through accumulated variance,correlation analysis,regression analysis,empirical orthogonal function,power spectrum function and spatial analysis tools of GIS.The result showed that summer precipitation occupied a relatively high proportion in the area with less annual precipitation on the Plateau and the correlation between summer precipitation and annual precipitation was strong.The altitude of these stations and summer precipitation tendency presented stronger positive correlation below 2000 m,with correlation value up to 0.604（α=0.01）.The subtracting tendency values between 1961-1983 and 1984-2004 at five altitude ranges（2000-2500 m,2500-3000 m,3500-4000 m,4000-4500 m and above 4500 m）were above zero and accounted for 71.4%of the total.Using empirical orthogonal function, summer precipitation could be roughly divided into three precipitation pattern fields：the Southeast Plateau Pattern Field,the Northeast Plateau Pattern field and the Three Rivers＇ Headstream Regions Pattern Field.The former two ones had a reverse value from the north to the south and opposite line was along 35°N.The potential cycles of the three pattern fields were 5.33a,21.33a and 2.17a respectively,tested by the confidence probability of 90%.The station altitudes and summer precipitation potential cycles presented strong negative correlation in the stations above 4500 m,with correlation value of-0.626（α=0.01）.In Three Rivers Headstream Regions summer precipitation cycle decreased as the altitude rose in the stations above 3500 m and increased as the altitude rose in those below 3500 m.The empirical orthogonal function analysis in June precipitation,July precipitation and August precipitation showed that the June precipitation pattern field was similar to the July＇s,in which southern Plateau was positive and northern Plateau negative.But positive value area in July precipitation pattern field was obviously less than June＇s.The August pattern field was totally opposite to June＇s and July＇s.The positive area in August pattern field jumped from the southern Plateau to the northern Plateau.展开更多
The logistics clusters are the result of concentration, scale and specialization of logistics activities, and their quantitative measurement and development evaluation provide an important foundation for improving the...The logistics clusters are the result of concentration, scale and specialization of logistics activities, and their quantitative measurement and development evaluation provide an important foundation for improving the land use efficiency and achieving economies of scale. Taking 289 cities at prefecture-level and above as research objects, this paper collected macro-statistical data of transport, postal and warehousing industry during 2000–2014, business registration data of more than 290 thousand logistics enterprises, and 170 thousand logistics points of interest（POI）. With the integration of multi-index and multi-source data, the evolution process and spatial pattern of logistics clusters in China were explored with the methods of Location Quotient（LQ）, Horizontal Cluster Location Quotient（HCLQ）, Logistics Employment Density（LED） and modified Logistics Establishments＇ Participation（LEP）. The development levels, types and modes of different logistics clusters were quantified. Several important findings are derived from the study.（1） The logistics clusters are mainly located on the east side of the Hu Huanyong Line, and the accumulative pattern evolves from group to block structure, featuring wide coverage and high concentration. The evolution of logistics clusters has two stages of rapid convergence and stable change, resulting in gradual increase in the development level and efficiency of logistics clusters and in emergence of spillover effect.（2） 21 mature logistics clusters are distributed in the core and sub-cities of the main metropolitan areas of 16 provincial-level administrative divisions, conforming to the government logistics and transport planning. 43 emerging logistics clusters are distributed in 21 provincial administrative divisions, and different types of cities have huge disparities which highlight the differentiation of the market behaviors and government planning among them.（3） The logistics clusters present differentiated development modes with the change of scales. In urban agglomerations scale, the nested ＂center-periphery＂ structures with ＂main nucleus-secondary cores-general nodes＂ are clarified. The polar nuclear development, networked and balanced development, single core and multipoint, multi-core multipoint hub-spoke development patterns are formed in different provincial administrative divisions.展开更多
Utilization of heterosis to develop hybrid cultivars can significantly increase yield of most crops including foxtail millet. However, previous foxtail millet hybrid cultivars have been largely developed from crosses ...Utilization of heterosis to develop hybrid cultivars can significantly increase yield of most crops including foxtail millet. However, previous foxtail millet hybrid cultivars have been largely developed from crosses between sterile lines and conventional varieties or between sterile lines and varieties that are geographically distent from the sterile lines. The research on classification of heterotic classes and determinetaion of heterotic patterns has not been reported, which results in uncertainty in selection of parents for crosses and delays progress in utilization of high yielding hybrids in large-scale commercial production. In this study, a core collection of 128 accessions from China was grouped into six classes using combined analyses of population structure, pedigree, and clustering. The classification was conducted based mainly on molecular clustering of genotypic data, also considered the population structure and mathematical clustering using phenotypic data, and was finally validated through pedigree analysis. According to the transgressive and superstandard heterosis for grain yield, plant height, panicle length, panicle diameter, single panicle weight, grain weight per panicle, and 1000-grain weight collected from an incomplete-diallel-cross experiment, we identified six superior heterosis patterns (C2/C1, C2/C4, C2/C5, C2/C6, C1/C5 and C4/C5) and four inferior heterosis patterns (C1/C3, C1/C4, C1/C6 and C4/C6), and explored their potential applications in millet hybrid breeding. This study laid a foundation for effective use of foxtail millet heterosis in improving millet hybrid yield.展开更多
Comprehensive and joint applications of GIS and chemometric approach were applied in identification and spatial patterns of coastal water pollution sources with a large data set （5 years （2000-2004）, 17 parameters...Comprehensive and joint applications of GIS and chemometric approach were applied in identification and spatial patterns of coastal water pollution sources with a large data set （5 years （2000-2004）, 17 parameters） obtained through coastal water monitoring of Southern Water Control Zone in Hong Kong. According to cluster analysis the pollution degree was significantly different between September-next May （the 1st period） and June-August （the 2nd period）. Based on these results, four potential pollution sources, such as organic/eutrophication pollution, natural pollution, mineral/anthropic pollution and fecal pollution were identified by factor analysis/principal component analysis. Then the factor scores of each monitoring site were analyzed using inverse distance weighting method, and the results indicated degree of the influence by various potential pollution sources differed among the monitoring sites. This study indicated that hybrid approach was useful and effective for identification of coastal water pollution source and spatial patterns.展开更多
文摘Industrial cluster is an aggregation of the related enterprises and institutions in certain field and in certain place. There are mainly three patterns for industrial clusters： market-oriented cluster, foreign fund oriented cluster and endogenous brand oriented cluster. Many economists have established their own theories about the patterns industrial cluster, but there are few dealing with one big enterprises and its cluster pattern. This paper, taking Haier household electrical appliance as an example, is trying to study one model of Chinese industrial cluster and analyze its characteristics with their effects on economy, as.well as the advantages together with the related suggestions from the authors.
基金This work is supported by the National Natural Science Foundationof China under Grants No. 41471371.
文摘The discovery of gradual moving object clusters pattern from trajectory streams allows characterizing movement behavior in real time environment,which leverages new applications and services.Since the trajectory streams is rapidly evolving,continuously created and cannot be stored indefinitely in memory,the existing approaches designed on static trajectory datasets are not suitable for discovering gradual moving object clusters pattern from trajectory streams.This paper proposes a novel algorithm of gradual moving object clusters pattern discovery from trajectory streams using sliding window models.By processing the trajectory data in current window,the mining algorithm can capture the trend and evolution of moving object clusters pattern.Firstly,the density peaks clustering algorithm is exploited to identify clusters of different snapshots.The stable relationship between relatively few moving objects is used to improve the clustering efficiency.Then,by intersecting clusters from different snapshots,the gradual moving object clusters pattern is updated.The relationship of clusters between adjacent snapshots and the gradual property are utilized to accelerate updating process.Finally,experiment results on two real datasets demonstrate that our algorithm is effective and efficient.
基金funded by the National Basic Research Program of China (2009CB118605)the National Natural Science Fund of China (30370853)
文摘Plant photosynthetic rate is affected by stomatal status and internal CO2 carboxylation. Understanding which process determines photosynthetic rate is essential for developing strategies for breeding crops with high photosynthetic efficiency. In this study, we identified different physiological patterns of photosynthetic rate in two different rice populations. Photosynthetic gas exchange parameters were measured during the flowering stage in two rice populations. Clustering and correlation analyses were performed on the resulting data. Five or six groups were defined by K-means clustering according to differences in net photosynthetic rates(Pn). According to differences in stomatal conductance(gs) and carboxylation efficiency(CE), each group was clustered into three subgroups characterized by physiological patterns stomatal pattern, carboxylation pattern, and intermediate pattern. Pn was significantly correlated with gs(r = 0.810) and CE(r = 0.531). Pn was also significantly correlated with gs and CE in the three physiological patterns. The correlation coefficients were highest in the stomatal pattern(0.905 and 0.957) and lowest in the carboxylation pattern(0.825 and 0.859). Higher correlation coefficients between Pn and gs or CE in the three physiological patterns indicate that clustering is very important for understanding factors limiting rice photosynthesis. ? 2013 Production and hosting by Elsevier B.V. on behalf of Crop Science Society of
文摘Purpose: To present a method for systematically mapping diversity of publication patterns at the author level in the social sciences and humanities in terms of publication type, publication language and co-authorship.Design/methodology/approach: In a follow-up to the hard partitioning clustering by Verleysen and Weeren in 2016, we now propose the complementary use of fuzzy cluster analysis, making use of a membership coefficient to study gradual differences between publication styles among authors within a scholarly discipline. The analysis of the probability density function of the membership coefficient allows to assess the distribution of publication styles within and between disciplines.Findings: As an illustration we analyze 1,828 productive authors affiliated in Flanders, Belgium. Whereas a hard partitioning previously identified two broad publication styles, an international one vs. a domestic one, fuzzy analysis now shows gradual differences among authors. Internal diversity also varies across disciplines and can be explained by researchers’ specialization and dissemination strategies.Research limitations: The dataset used is limited to one country for the years 2000–2011; a cognitive classification of authors may yield a different result from the affiliation-based classification used here.Practical implications: Our method is applicable to other bibliometric and research evaluation contexts, especially for the social sciences and humanities in non-Anglophone countries.Originality/value: The method proposed is a novel application of cluster analysis to the field of bibliometrics. Applied to publication patterns at the author level in the social sciences and humanities, for the first time it systematically documents intra-disciplinary diversity.
基金Support for this work was through NIH NIDCR NRSA #T32-DE07255
文摘Aim Cluster analysis was conducted on data from 5,169 United States （U.S.） Arizona children, age＇s 5-59-months with the goal of delineating patterns of caries in the primary dentition of pre-school children without a priori pattern definitions. Methodology Cluster analyses were conducted using all data for children ages 0-4 years in aggregate： 1） for all subjects, and 2） for subjects without crowned restored teeth. Each of these two sets of analyses consisted of 8 differently specified cluster analyses as a validation procedure. Results The caries patterns identified from the clustering analysis are： 1） smooth surfaces （other than the maxillary incisor）, 2） maxillary incisor, 3） occlusal surfaces of first molars, and 4） pit and fissure surfaces of second molars. Conclusion The cluster analysis findings were consistent with results produced by multidimensional scaling. These cross-validated patterns may represent resulting disease conditions from different risks or the timing of various risk factor exposures. As such, the patterns may be useful case definitions for caries risk factor investigations in children under 60 months of age.
文摘Patterned-based time series segmentation (PTSS) is an important task for many time series data mining applications. In this paper, according to the characteristics of PTSS, a generalized model is proposed for PTSS. First, a new inter-pretation for PTSS is given by comparing this problem with the prototype-based clustering (PC). Then, a novel model, called clustering-inverse model (CI-model), is presented. Finally, two algorithms are presented to implement this model. Our experimental results on artificial and real-world time series demonstrate that the proposed algorithms are quite effective.
文摘目的系统整理并归纳总结乳腺癌的中医证候分布及临床组方用药论治规律,为临床应用中医药治疗乳腺癌提供选方用药思路借鉴。方法检索建库至2024年6月30日中国知网(CNKI)、万方医学网(WANFANG MED ONLINE)、维普网(VIP)、中国生物医学服务系统(SinoMed)文献数据库有关中医诊治乳腺癌的文献资料,建立数据库,通过Excel、SPSS Statistics、SPSS Modeler软件对证型、症状、方剂、药物进行频数统计、系统聚类和Apriori关联规则分析。结果共筛选得到文献164篇,中医证型36个,其中气血两虚、肝郁脾虚、肝郁气滞、气阴两虚、肝肾阴虚、瘀毒互结为常见证型;包含方剂257首,其中成方47首,以逍遥散、八珍汤、六君子汤为主;涉及中药281味,高频中药有白术、茯苓、甘草、黄芪、当归、柴胡、白芍、陈皮、白花蛇舌草等,功效以补虚药、清热药、活血化瘀药、理气药为主,主归肝、脾、肾经;45味高频中药系统聚类分析得到4个聚类方;关联规则分析得到20个药物组合。结论乳腺癌患者以气血两虚、肝郁脾虚、肝郁气滞证为主,在遣方用药上以益气健脾、滋阴养血为基本治法,同时辅以行气活血、清热解毒散结等药物辨证论治。
基金Supported by the National Natural Science Foundation of China[the Patterns Differentiation Mode of Main TCM Clinical Symptoms Based on Complex System Method(No.81270050)Information Extraction From TCM Inquiry and the Deducting Method of Patterns Differentiation Based on Feature Selection(No.30901897)+2 种基金Common Syndrome Diagnosis of Traditional Chinese Medicine Based on The Integration of Four Diagnosis Methods(No.81173199)]College Students' Scientific Innovation Foundation of Shanghai University of TCM[SHUTCMCXHDZ(2011)03]the Foundation for Training Talents of National Basic Scientific Research(No.J1103607)
文摘OBJECTIVE: Apply spectral clustering to analyze the patterns of symptoms in patients with chronic gastritis(CG).METHODS: Based on 919 CG subjects, we applied mutual information feature selection to choose the positively correlated symptoms with each pattern.Then, we used the Shi and Malik spectral clustering algorithm to select the top 20 correlated symptoms.RESULTS: We ascertained the results of six patterns.There were three categories for the pattern of accumulation of damp heat in the spleen-stomach(0.00332). There were six categories for the pattern of dampness obstructing the spleen-stomach(0.02466). There were two categories for the pattern of spleen-stomach Qi deficiency(0.013 89).There were three categories for the pattern of spleen-stomach deficiency cold(0.009 15). There were five categories for the pattern of liver-Qistagnation(0.01910).There were four categories for the pattern of stagnant heat in the liver-stomach(0.00585).CONCLUSION: Most of the spectral clustering results of the symptoms of CG patterns were in accordance with clinical experience and Traditional Chinese Medicine theory. Most categories suggested the nature and/or location of the disease.
基金CAS Action-plan for West Development, KZCX2-XB2-06-03 National Natural Science Foundation of China, No.30500064
文摘The summer day-by-day precipitation data of 97 meteorological stations on the Qinghai-Tibet Plateau from 1961 to 2004 were selected to analyze the temporal-spatial distribution through accumulated variance,correlation analysis,regression analysis,empirical orthogonal function,power spectrum function and spatial analysis tools of GIS.The result showed that summer precipitation occupied a relatively high proportion in the area with less annual precipitation on the Plateau and the correlation between summer precipitation and annual precipitation was strong.The altitude of these stations and summer precipitation tendency presented stronger positive correlation below 2000 m,with correlation value up to 0.604（α=0.01）.The subtracting tendency values between 1961-1983 and 1984-2004 at five altitude ranges（2000-2500 m,2500-3000 m,3500-4000 m,4000-4500 m and above 4500 m）were above zero and accounted for 71.4%of the total.Using empirical orthogonal function, summer precipitation could be roughly divided into three precipitation pattern fields：the Southeast Plateau Pattern Field,the Northeast Plateau Pattern field and the Three Rivers＇ Headstream Regions Pattern Field.The former two ones had a reverse value from the north to the south and opposite line was along 35°N.The potential cycles of the three pattern fields were 5.33a,21.33a and 2.17a respectively,tested by the confidence probability of 90%.The station altitudes and summer precipitation potential cycles presented strong negative correlation in the stations above 4500 m,with correlation value of-0.626（α=0.01）.In Three Rivers Headstream Regions summer precipitation cycle decreased as the altitude rose in the stations above 3500 m and increased as the altitude rose in those below 3500 m.The empirical orthogonal function analysis in June precipitation,July precipitation and August precipitation showed that the June precipitation pattern field was similar to the July＇s,in which southern Plateau was positive and northern Plateau negative.But positive value area in July precipitation pattern field was obviously less than June＇s.The August pattern field was totally opposite to June＇s and July＇s.The positive area in August pattern field jumped from the southern Plateau to the northern Plateau.
基金National Natural Science Foundation of China,No.71603219,No.41501123
文摘The logistics clusters are the result of concentration, scale and specialization of logistics activities, and their quantitative measurement and development evaluation provide an important foundation for improving the land use efficiency and achieving economies of scale. Taking 289 cities at prefecture-level and above as research objects, this paper collected macro-statistical data of transport, postal and warehousing industry during 2000–2014, business registration data of more than 290 thousand logistics enterprises, and 170 thousand logistics points of interest（POI）. With the integration of multi-index and multi-source data, the evolution process and spatial pattern of logistics clusters in China were explored with the methods of Location Quotient（LQ）, Horizontal Cluster Location Quotient（HCLQ）, Logistics Employment Density（LED） and modified Logistics Establishments＇ Participation（LEP）. The development levels, types and modes of different logistics clusters were quantified. Several important findings are derived from the study.（1） The logistics clusters are mainly located on the east side of the Hu Huanyong Line, and the accumulative pattern evolves from group to block structure, featuring wide coverage and high concentration. The evolution of logistics clusters has two stages of rapid convergence and stable change, resulting in gradual increase in the development level and efficiency of logistics clusters and in emergence of spillover effect.（2） 21 mature logistics clusters are distributed in the core and sub-cities of the main metropolitan areas of 16 provincial-level administrative divisions, conforming to the government logistics and transport planning. 43 emerging logistics clusters are distributed in 21 provincial administrative divisions, and different types of cities have huge disparities which highlight the differentiation of the market behaviors and government planning among them.（3） The logistics clusters present differentiated development modes with the change of scales. In urban agglomerations scale, the nested ＂center-periphery＂ structures with ＂main nucleus-secondary cores-general nodes＂ are clarified. The polar nuclear development, networked and balanced development, single core and multipoint, multi-core multipoint hub-spoke development patterns are formed in different provincial administrative divisions.
文摘Utilization of heterosis to develop hybrid cultivars can significantly increase yield of most crops including foxtail millet. However, previous foxtail millet hybrid cultivars have been largely developed from crosses between sterile lines and conventional varieties or between sterile lines and varieties that are geographically distent from the sterile lines. The research on classification of heterotic classes and determinetaion of heterotic patterns has not been reported, which results in uncertainty in selection of parents for crosses and delays progress in utilization of high yielding hybrids in large-scale commercial production. In this study, a core collection of 128 accessions from China was grouped into six classes using combined analyses of population structure, pedigree, and clustering. The classification was conducted based mainly on molecular clustering of genotypic data, also considered the population structure and mathematical clustering using phenotypic data, and was finally validated through pedigree analysis. According to the transgressive and superstandard heterosis for grain yield, plant height, panicle length, panicle diameter, single panicle weight, grain weight per panicle, and 1000-grain weight collected from an incomplete-diallel-cross experiment, we identified six superior heterosis patterns (C2/C1, C2/C4, C2/C5, C2/C6, C1/C5 and C4/C5) and four inferior heterosis patterns (C1/C3, C1/C4, C1/C6 and C4/C6), and explored their potential applications in millet hybrid breeding. This study laid a foundation for effective use of foxtail millet heterosis in improving millet hybrid yield.
基金Project supported by the National Basic Research Program (973) of China(No. 2005CB724205)China Scholarship Programs of the Ministry ofEducation of China (No. 2006100766).
文摘Comprehensive and joint applications of GIS and chemometric approach were applied in identification and spatial patterns of coastal water pollution sources with a large data set （5 years （2000-2004）, 17 parameters） obtained through coastal water monitoring of Southern Water Control Zone in Hong Kong. According to cluster analysis the pollution degree was significantly different between September-next May （the 1st period） and June-August （the 2nd period）. Based on these results, four potential pollution sources, such as organic/eutrophication pollution, natural pollution, mineral/anthropic pollution and fecal pollution were identified by factor analysis/principal component analysis. Then the factor scores of each monitoring site were analyzed using inverse distance weighting method, and the results indicated degree of the influence by various potential pollution sources differed among the monitoring sites. This study indicated that hybrid approach was useful and effective for identification of coastal water pollution source and spatial patterns.
