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关于■-群的一些充分条件 被引量:1
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作者 苏跃斌 《内江师范学院学报》 2009年第4期13-14,59,共3页
从群系理论出发,利用有限群的某些子群弱拟正规性,得到了局部群系和包含超可解群类的饱和群系的一些充分条件.
关键词 弱拟正规子 ■-群 局部
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Xylooligosaccharides Alleviate Inflammatory Dermatoses and Related Depression-Like Behaviors in Atopic Dermatitis Mice Induced by 2,4-Dinitrofluorobenzene
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作者 FANG Mingyu TANG Liu +6 位作者 LI Zimo NIE Tingting CHEN Shaoze FANG Zhenfeng SHI Lu HU Song CAO Xiaoqin 《食品科学》 EI CAS CSCD 北大核心 2024年第17期113-126,共14页
Objective:To investigate the influence of xylooligosaccharides on skin inflammation,behavioral characteristics,neurotransmitters,and gut flora in a mouse model of atopic dermatitis(AD)induced by 2,4-dinitrofluorobenze... Objective:To investigate the influence of xylooligosaccharides on skin inflammation,behavioral characteristics,neurotransmitters,and gut flora in a mouse model of atopic dermatitis(AD)induced by 2,4-dinitrofluorobenzene(DNFB).Methods:The AD mouse model was created by administration of DNFB for 14 consecutive days.The scoring atopic dermatitis index,enzyme-linked immunosorbent assay(ELISA),histopathology,and immunohistochemical analyses were used to assess inflammation and depression-like behaviors.Furthermore,high-throughput 16S rRNA gene sequencing was used to determine the composition of fecal microbiota.Results:Xylooligosaccharides treatment reduced the number of scratches and skin thickness,mast cell infiltration and the levels of immunoglobulin(Ig)E and T-helper cytokines compared with the AD model group.Meanwhile,xylooligosaccharides treatment reduced the immobility time of mice in the forced swimming test and increased the total movement distance and movement distance in the center area in the open-field test.Furthermore,5-hydroxytryptamine and dopamine expression in the brain was increased following xylooligosaccharides treatment.Using network pharmacology,Gene Ontology analysis showed that the targets were mainly enriched in phosphatase binding and the regulation of leukocyte differentiation,which ameliorated AD mainly through the hypoxia inducible factor-1 and phosphatidylinositide 3-kinase-protein kinase B pathways.16S rRNA gene sequencing,diversity indices,and gut microbial taxonomic composition analysis showed DNFB-induced changes in intestinal microbiota diversity in AD mice.Comparative analysis indicated that xylooligosaccharides intake improved the gut microbiome by dramatically enhancing the concentration of Lactobacillus while decreasing the concentration of Bacteroides in mice.Conclusion:Xylooligosaccharides reduce inflammatory dermatosis and related depression-like behaviors via regulating intestinal homeostasis,having medicinal value as a nutritional and functional ingredient. 展开更多
关键词 atopic dermatitis intestinal flora XYLOOLIGOSACCHARIDES depression-like behaviors
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Application and optimization design of non-obstructive particle damping-phononic crystal vibration isolator in viaduct structure-borne noise reduction
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作者 SHI Duo-jia ZHAO Cai-you +3 位作者 ZHANG Xin-hao ZHENG Jun-yuan WEI Na-chao WANG Ping 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2513-2531,共19页
The problems associated with vibrations of viaducts and low-frequency structural noise radiation caused by train excitation continue to increase in importance.A new floating-slab track vibration isolator-non-obstructi... The problems associated with vibrations of viaducts and low-frequency structural noise radiation caused by train excitation continue to increase in importance.A new floating-slab track vibration isolator-non-obstructive particle damping-phononic crystal vibration isolator is proposed herein,which uses the particle damping vibration absorption technology and bandgap vibration control theory.The vibration reduction performance of the NOPD-PCVI was analyzed from the perspective of vibration control.The paper explores the structure-borne noise reduction performance of the NOPD-PCVIs installed on different bridge structures under varying service conditions encountered in practical engineering applications.The load transferred to the bridge is obtained from a coupled train-FST-bridge analytical model considering the different structural parameters of bridges.The vibration responses are obtained using the finite element method,while the structural noise radiation is simulated using the frequency-domain boundary element method.Using the particle swarm optimization algorithm,the parameters of the NOPD-PCVI are optimized so that its frequency bandgap matches the dominant bridge structural noise frequency range.The noise reduction performance of the NOPD-PCVIs is compared to the steel-spring isolation under different service conditions. 展开更多
关键词 non-obstructive particle damping phononic crystal vibration isolator band gap optimization floating-slab track bridge structure-borne noise control particle swarm optimization
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缩节胺和硝普钠对棉花幼苗根际土壤酶活性及细菌群落的影响
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作者 吴建飞 刘茜 +3 位作者 李璇 温天旺 杨文亭 汤飞宇 《棉花学报》 CSCD 北大核心 2023年第5期353-364,共12页
【目的】研究棉花幼苗施用缩节胺(1,1-dimethyl piperidinium chloride,DPC)和一氧化氮供体硝普钠(sodium nitroprusside,SNP)后根际土壤酶活性及细菌群落的变化,探讨与棉花幼苗生长相关的根际生物学指标。【方法】采用陆地棉品系A201... 【目的】研究棉花幼苗施用缩节胺(1,1-dimethyl piperidinium chloride,DPC)和一氧化氮供体硝普钠(sodium nitroprusside,SNP)后根际土壤酶活性及细菌群落的变化,探讨与棉花幼苗生长相关的根际生物学指标。【方法】采用陆地棉品系A201进行穴盘育苗试验。于棉花1叶1心期分别在叶片均匀涂抹50 mg·L^(-1)DPC、500μmol·L^(-1)SNP,以涂抹去离子水为对照。于3叶1心期取根际土壤分析蔗糖酶、脲酶、过氧化氢酶、碱性磷酸酶活性,采用16S rRNA测序技术分析根际细菌多样性。【结果】DPC和SNP处理显著促进棉花根系生长,显著提高茎粗和植株干物质质量。DPC处理显著提高土壤脲酶和蔗糖酶的活性,SNP处理显著提高土壤蔗糖酶活性但显著降低脲酶的活性,但是DPC和SNP处理均未显著影响过氧化氢酶和碱性磷酸酶活性。DPC处理显著提高髌骨菌门(Patescibacteria)的相对丰度和土壤细菌群落的辛普森多样性指数(Simpson's diversity index),显著降低了绿弯菌门(Chloroflexi)和酸杆菌门(Acidobacteria)的相对丰度以及土壤细菌群落的香农-维纳多样性指数(Shannon Wiener’s diversity index)。冗余分析显示,DPC处理组的酵母菌科(Saccharimonadaceae)、TM7a属细菌的相对丰度比SNP处理组和对照组高;SNP处理组的纤维弧菌属(Cellvibrionaceae)细菌相对丰度高于DPC处理组和对照组;DPC和SNP处理组的根瘤菌科(Rhizobiaceae)细菌的相对丰度高于对照组,硝化螺旋菌科(Nitrospiraceae)和硝化螺旋菌属(Nitrospira)细菌的相对丰度低于对照组。脲酶活性与酵母菌科、TM7a属细菌的相对丰度呈显著正相关关系。【结论】DPC和SNP能够促进棉花幼苗根系及植株生长,并影响棉苗根际的土壤酶活性及细菌群落结构。 展开更多
关键词 棉花 缩节胺 硝普钠 土壤酶 细菌 丰度 多样性
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出土“書”類文獻視域下《群經平議》之平議--兼及相關問題辨析與文句闡釋
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作者 李昭陽 《出土文献综合研究集刊》 2022年第2期172-186,共15页
《群經平議》是俞樾經學研究的代表作,學者們對此書的評價差别很大。總體來説,批評大於褒獎。我們利用清華簡“書”類文獻相關篇目逐條分析《群經平議》校讀古書的方法與結論,發現俞樾的校讀頗有可取之處,以前學者們對俞樾的批評並不客... 《群經平議》是俞樾經學研究的代表作,學者們對此書的評價差别很大。總體來説,批評大於褒獎。我們利用清華簡“書”類文獻相關篇目逐條分析《群經平議》校讀古書的方法與結論,發現俞樾的校讀頗有可取之處,以前學者們對俞樾的批評並不客觀公正,《群經平議》的價值有必要進一步發掘。另外,我們梳理了相關問題的諸家舊説,還從訓詁學角度對相關文句中“德”與“能”的含義作了進一步闡釋。 展开更多
关键词 出土文獻 俞樾 經平議》 平議 闡釋
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神农架南坡小叶青冈+曼青冈常绿阔叶林主要木本植物生态位与种间联结 被引量:2
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作者 陈聪琳 赵常明 +7 位作者 刘明伟 徐凯 徐文婷 熊高明 葛结林 邓滢 申国珍 谢宗强 《生态学报》 CAS CSCD 北大核心 2024年第11期4889-4903,共15页
为揭示神农架南坡代表性常绿阔叶林主要木本植物的种间生态联系及群落演替趋势,以小叶青冈+曼青冈群系20个主要木本植物的190组种对为研究对象,通过生态位测定并区分生态位特化种和生态位泛化种以及种间联结性检验,分析该群落主要物种... 为揭示神农架南坡代表性常绿阔叶林主要木本植物的种间生态联系及群落演替趋势,以小叶青冈+曼青冈群系20个主要木本植物的190组种对为研究对象,通过生态位测定并区分生态位特化种和生态位泛化种以及种间联结性检验,分析该群落主要物种生态位与种间联结特征。主要结果:(1)该常绿阔叶林群落物种丰富,群落组成复杂,小叶青冈(Cyclobalanopsis myrsinifolia)的重要值(11.13%)和生态位宽度(58.3)均最大,占绝对优势,生态位宽度排序和重要值排序不一致,分布频度对生态位宽度影响较大。(2)将20种主要木本植物划分为生态位特化种(6种)、生态位泛化种(3种)、中性类群(11种),生态位分化程度较高,资源利用差异以及生境适应性是影响生态位分化的主要因素。(3)生态位宽度大的物种其生态位重叠和相似度较高,生态位重叠指数总体略低,大部分物种对环境或资源需求相似,但相似度不高,种间竞争较弱,种间关系比较稳定。(4)主要木本植物总体正联结显著(P<0.05),χ^(2)检验、联结系数AC、Spearman秩相关检验结果均显示种间正联结作用占优势,但大多数种对联结不显著,物种趋于独立分布。(5)通过聚类分析,将20种主要木本植物划分三大生态种组:建群种组,共生种组和边缘种组。研究表明,神农架南坡小叶青冈+曼青冈常绿阔叶林目前正处于相对稳定的演替中后期阶段,群落发育较成熟,生态位分化、生境选择以及资源需求互补或互利是影响该群落物种共存的主要原因。研究阐明了神农架南坡代表性常绿阔叶林主要物种之间实际相互作用以及群落特征,为深入理解群落物种共存原因以及群落演替规律提供依据。 展开更多
关键词 常绿阔叶林 种间关系 生态种组 物种共存
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Group Size and Composition of Black-and-White Snub-nosed Monkey (Rhinopithecus bieti) Estimated by Faecesof Sleeping Sites at Baima Snow Mountain 被引量:8
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作者 崔亮伟 钟泰 +1 位作者 肖林 肖文 《Zoological Research》 CAS CSCD 北大核心 2006年第4期337-343,共7页
This study was designed to introduce a new method of estimating group size and composition of black-andwhite snub-nosed monkeys (Rhinopithecus bieti ) on the basis of faecal amount at sleeping sites at Mt. Baima Nat... This study was designed to introduce a new method of estimating group size and composition of black-andwhite snub-nosed monkeys (Rhinopithecus bieti ) on the basis of faecal amount at sleeping sites at Mt. Baima Nature Reserve. The monkeys spend nights in the form of one-male, multi-female units (OMUs) and all-male units (AMU), and their faecal pellets can be classified into three categories: adult males (the largest), adult females (moderate) and immatures (the smallest) based on their size. Total pellets were counted under sleeping trees used for two nights at Nanren village (99°04′E, 28°34′N, northwest of Yunnan Province, China) in each of four seasons in 2000- 2001. Moreover, data on group composition were collected when the monkeys were passing through an open gully in November 2001. Since the number of adults in OMUs shows a positive significant correlation with the amount of pellets amount in each season, the mean number of feces produced per night per individual is the slope of the regression lines. Thus, group size and composition can be relatively reliably and accurately estimated by the faeces under trees compared with the previous methods of estimation, including the use of monkeys' activities and tracks such as broken branches on steep slopes, in deep gorges and under lower visibility. The use of pellets for population estimates displayed 9.4% deviation in regards to population size of adult females. Some causes of the bias were also discussed. The method might be applicable to other monkey groups of this species if their habitats and main foods are similar to those of the study group. 展开更多
关键词 FECES Group composition Group size Rhinopithecus bieti Sleeping site
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Population Genetic Diversity in Chinese Pomegranate (Punica granatum L.) Cultivars Revealed by Fluorescent-AFLP Markers 被引量:14
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作者 苑兆和 尹燕雷 +2 位作者 曲健禄 朱丽琴 李云 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第12期1061-1071,共11页
Eighty-five pomegranate (Punica granatum L.) cultivars from six geographical populations located at Shandong, Anhui, Shaanxi, Henan, Yunnan, and Xinjiang Provinces were studied for its population genetic diversity b... Eighty-five pomegranate (Punica granatum L.) cultivars from six geographical populations located at Shandong, Anhui, Shaanxi, Henan, Yunnan, and Xinjiang Provinces were studied for its population genetic diversity by means of fluorescent-AFLP markers. The results indicated that 135-185 polymorphic loci were amplified by eight pairs of primers at species level. An average of 158.25 polymorphic loci was amplified for each primer combination. The polymorphism percentage ranged from 62.5% to 86.11%, and the average polymorphism percentage was 73.26%. This indicated that there was plentiful genetic diversity in pomegranate cultivars. The genetic diversity at the species level was higher than that at the population level. The order of the genetic diversity was Henan population 〉 Xinjiang population 〉 Shaanxi population 〉 Anhui population 〉 Shandong population 〉 Yunnan population. Variance analysis showed that there was significant difference between populations in genetic diversity. The genetic differentiation coefficient between populations (Gsr) was 0.2018, which indicated that gene differentiation was mainly within the population, and between populations, it accounted for 20.18% of the total variation. Gene flow (Nm) between the populations measured was 1.9027 based on the genetic differentiation coefficient between populations, indicating that there was mild gene flow between populations. The UPGMA cluster analysis showed that most accessions from the same population were clustered together, but there was partly gene exchange. All genetic parameters indicated that there was plentiful genetic diversity in pomegranate cultivars in China, of which Henan population was significantly higher than the other populations, and it had wide application foreground in pomegranate breeding in China. 展开更多
关键词 POMEGRANATE AFLP marker genetic diversity population genetic structure
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Population Genetic Structure in Apricot (Prunus armeniaca L.) Cultivars Revealed by Fluorescent-AFLP Markers in Southern Xinjiang,China 被引量:13
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作者 苑兆和 陈学森 +3 位作者 何天明 冯建荣 冯涛 张春雨 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第11期1037-1047,共11页
Population-wide genetic structure was studied using fluorescent-AFLP markers on 85 apricot (Prunus armeniaca L.) cultivars collected from Kuche, Kashi, Hetian in the Tarim Basin, southern Xinjiang Uygur Autonomous R... Population-wide genetic structure was studied using fluorescent-AFLP markers on 85 apricot (Prunus armeniaca L.) cultivars collected from Kuche, Kashi, Hetian in the Tarim Basin, southern Xinjiang Uygur Autonomous Region of China. The purpose of this study was to determine the genetic structure and genotypic diversity among the different eco-geographical populations. Based on the results from this study, 8 pairs of fluorescent-AFLP primers showed clear electrophoregram and high polymorphism amongst the 64 pairs of EcoR Ⅰ/Mse Ⅰ (Mse Ⅰ - a FAM fluorescent marked primer) primers screened. There was a significant polymorphic difference for the same primer pair in different populations and for the same population with different primer pairs. The percentage of polymorphic loci (P) at species level was higher than Kuche, Hetian, Kashi population levels, respectively. The Nei's gene diversity index (H) and Shannon's information index (I) at species level were higher than those of Kuche, Hetian, and Kashi at population level, respectively. H and I of Kuche population were the highest amongst the three populations. Apricot population genetic diversity was found mainly within the population, Genetic differentiation coefficient between populations (GST) was 0.0882. Gene flow Nm between the populations was 5.1689. Population genetic identity was between 0.9772-0.9811 and genetic distance was between 0.0191-0.0232. These results further indicated that the similarity between populations was higher and the genetic distance between populations was smaller. The UPGMA cluster analysis indicates that the geographical populations at Kuche, Kashi, Hetian were relatively independent Mendelian populations. Concurrently, there was also partial gene exchange between the populations. All the evidences indicated that the genetic diversity in Kuche population was the highest, suggesting that it could be a transition population from wild apricot to cultivated apricot. There were abundant genetic diversities in apricot cultivar populations in southern Xinjiang, China, which provide promising germplasm for further breeding and theoretical basis for biodiversity conservation and utilization for apricot population in this area. 展开更多
关键词 Prunus armeniaca POPULATION AFLP marker genetic structure' gene flow
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Characteristics,classification and ordination of riparian plant communities in the Three-Gorges areas 被引量:12
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作者 江明喜 邓红兵 蔡庆华 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第2期111-114,163-164,共4页
Sixteen different vegetation types of grassland and shrubland were selected to study the component and diversity of plant species of riparian plant communities along main channel in the Three-Gorges areas. Species ric... Sixteen different vegetation types of grassland and shrubland were selected to study the component and diversity of plant species of riparian plant communities along main channel in the Three-Gorges areas. Species richness (s), Simpson index (D), and Shannon-Weiner index (H) were used to study the biodiversity and the hierarchical classification was carried out by the methods of TWINSPAN and DCA ordination. The results showed that the components of flora were complex and dominated by the temperate type in the riparian plant communities. Species diversity was not different between the communities, but Shannon-Weiner indexes of different layers in some grassland were significantly different. TWINSPAN and DCA indicated that riparian plant communities distributed along the gradient of moisture. 展开更多
关键词 Three-Gorges areas Riparian zone Plant community CLASSIFICATION ORDINATION TWINSPAN DCA
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HEURISTIC PARTICLE SWARM OPTIMIZATION ALGORITHM FOR AIR COMBAT DECISION-MAKING ON CMTA 被引量:18
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作者 罗德林 杨忠 +2 位作者 段海滨 吴在桂 沈春林 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第1期20-26,共7页
Combining the heuristic algorithm (HA) developed based on the specific knowledge of the cooperative multiple target attack (CMTA) tactics and the particle swarm optimization (PSO), a heuristic particle swarm opt... Combining the heuristic algorithm (HA) developed based on the specific knowledge of the cooperative multiple target attack (CMTA) tactics and the particle swarm optimization (PSO), a heuristic particle swarm optimization (HPSO) algorithm is proposed to solve the decision-making (DM) problem. HA facilitates to search the local optimum in the neighborhood of a solution, while the PSO algorithm tends to explore the search space for possible solutions. Combining the advantages of HA and PSO, HPSO algorithms can find out the global optimum quickly and efficiently. It obtains the DM solution by seeking for the optimal assignment of missiles of friendly fighter aircrafts (FAs) to hostile FAs. Simulation results show that the proposed algorithm is superior to the general PSO algorithm and two GA based algorithms in searching for the best solution to the DM problem. 展开更多
关键词 air combat decision-making cooperative multiple target attack particle swarm optimization heuristic algorithm
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Driving fatigue fusion detection based on T-S fuzzy neural network evolved by subtractive clustering and particle swarm optimization 被引量:6
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作者 孙伟 张为公 +1 位作者 李旭 陈刚 《Journal of Southeast University(English Edition)》 EI CAS 2009年第3期356-361,共6页
In order to improve the accuracy and reliability of the driving fatigue detection based on a single feature, a new detection algorithm based on multiple features is proposed. Two direct driver's facial features refle... In order to improve the accuracy and reliability of the driving fatigue detection based on a single feature, a new detection algorithm based on multiple features is proposed. Two direct driver's facial features reflecting fatigue and one indirect vehicle behavior feature indicating fatigue are considered. Meanwhile, T-S fuzzy neural network(TSFNN)is adopted to recognize the driving fatigue of drivers. For the structure identification of the TSFNN, subtractive clustering(SC) is used to confirm the fuzzy rules and their correlative parameters. Moreover, the particle swarm optimization (PSO)algorithm is improved to train the TSFNN. Simulation results and experiments on vehicles show that the proposed algorithm can effectively improve the convergence speed and the recognition accuracy of the TSFNN, as well as enhance the correct rate of driving fatigue detection. 展开更多
关键词 driving fatigue fusion detection particle swarm optimization(PSO) subtractive clustering(SC)
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NSGA-Ⅱ based traffic signal control optimization algorithm for over-saturated intersection group 被引量:8
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作者 李岩 过秀成 +1 位作者 陶思然 杨洁 《Journal of Southeast University(English Edition)》 EI CAS 2013年第2期211-216,共6页
In order to improve the efficiency of traffic signal control for an over-saturated intersection group, a nondominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ) based traffic signal control optimization algorithm is prop... In order to improve the efficiency of traffic signal control for an over-saturated intersection group, a nondominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ) based traffic signal control optimization algorithm is proposed. The throughput maximum and average queue ratio minimum for the critical route of the intersection group are selected as the optimization objectives of the traffic signal control for the over-saturated condition. The consequences of the efficiency between traffic signal timing plans generated by the proposed algorithm and a commonly utilized signal timing optimization software Synchro are compared in a VISSIM signal control application programming interfaces (SCAPI) simulation environment by using real filed observed traffic data. The simulation results indicate that the signal timing plan generated by the proposed algorithm is more efficient in managing oversaturated flows at intersection groups, and, thus, it has the capability of optimizing signal timing under the over-saturated conditions. 展开更多
关键词 traffic signal control optimization algorithm intersection group over-saturated status NSGA-H algorithm
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The changes of co-possession of plant species between communities with altitudes on northern slope of Changbai Mountain 被引量:3
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作者 邓红兵 郝占庆 王庆礼 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第2期89-92,146,共4页
Twenty plots were investigated on northern slope of Changbai Mountain at an attitude interval of 100 m (from 700 to 2600 m). The species co-possession between plant communities at different altitudes was analyzed by J... Twenty plots were investigated on northern slope of Changbai Mountain at an attitude interval of 100 m (from 700 to 2600 m). The species co-possession between plant communities at different altitudes was analyzed by Jaccard index. The analytical results showed that the co-possession calculated according to species in different layers or all species between adjacent communities was higher than that between disjunct communities. The co-possessions between adjacent communities calculated by species in different layers had comparability and dissimilarity. If the two adjacent communities belong to different types of vegetation, then their co-possession was lower. The peak values and valley values of species co-possession between communities along elevation gradient just matched vegetation gradient patterns, and species subrogation of shrubs had more obvious rule on northern slope of Changbai Mountain. Co-possessions between communities with same altitude difference were much similar, and it decreased as the increase of elevation difference, which showed that species compositions in different layers of the communities were highly related. 展开更多
关键词 Changbai Mountain Co-possession Plant community Altitude gradient
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Role of Wind-Sand Disturbance in the Formation and Development of Tamarix taklamakanensis Community 被引量:9
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作者 何兴东 高玉葆 任安芝 《Acta Botanica Sinica》 CSCD 2003年第11期1285-1290,共6页
Formation, development and degeneration of Tamarix taklamakanensis M.T. Liu community may be affected by wind-sand disturbance. On the basis of field survey and experiments that took eight years from 1994, it was foun... Formation, development and degeneration of Tamarix taklamakanensis M.T. Liu community may be affected by wind-sand disturbance. On the basis of field survey and experiments that took eight years from 1994, it was found that the plant community was formed in wet and low-lying land, developed in sand burying land, and died out in the land with strong wind erosion and severe sand burying. In the initial stage of the community formation, the low-lying land that was formed by wind erosion provided a suitable habitat for seed germination and plant rooting, but salt stress from ground water reduced seedling survival rate. In the developing stage of the community, sand burying stimulated vigorous growth of the shrubs. In the degenerative stage of the community, the wind erosion and sand burying resulted in dying out of the shrubs. It is therefore concluded that wind-sand disturbance has a positive role in the formation and development of the community, and is in a close association with the process of the community degeneration. Taking the habitat of T taklamakanensis into account, it may be appropriate to note that, under the conditions of frequent disturbance and severe stress, desert pioneer species are adaptable and able to survive. This might be a supplement to the CSR strategy. 展开更多
关键词 Takla Makan Tamarix taklamakanensis wind-sand disturbance community formation and development plant strategy
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从群母论浊声和摩擦——实验音韵学在汉语音韵学中的实验 被引量:43
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作者 朱晓农 《语言研究》 CSSCI 北大核心 2003年第2期5-18,共14页
上古群母字部份在中古以前擦化,部份在中古以后清化,这是音韵学常识。但为什么这么变,却是以前没有问过的问题。本文以实验语音学、类型学为工具来解答这个问题。并连带着处理浊声清化、浊擦音、日母元音值等问题。本文提倡的汉语实验... 上古群母字部份在中古以前擦化,部份在中古以后清化,这是音韵学常识。但为什么这么变,却是以前没有问过的问题。本文以实验语音学、类型学为工具来解答这个问题。并连带着处理浊声清化、浊擦音、日母元音值等问题。本文提倡的汉语实验音韵学以普遍音变现象为考察对象,从物理、生理、心理学中的普遍原理来探索发生在汉语中的普遍音变的条件。而什么是普遍音变则是从共时类型学和反复发生的历史音变来确定的。 展开更多
关键词 实验音韵学 普遍音变 音变顺序 日母 浊声 摩擦
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Springback prediction for incremental sheet forming based on FEM-PSONN technology 被引量:6
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作者 韩飞 莫健华 +3 位作者 祁宏伟 龙睿芬 崔晓辉 李中伟 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第4期1061-1071,共11页
In the incremental sheet forming (ISF) process, springback is a very important factor that affects the quality of parts. Predicting and controlling springback accurately is essential for the design of the toolpath f... In the incremental sheet forming (ISF) process, springback is a very important factor that affects the quality of parts. Predicting and controlling springback accurately is essential for the design of the toolpath for ISF. A three-dimensional elasto-plastic finite element model (FEM) was developed to simulate the process and the simulated results were compared with those from the experiment. The springback angle was found to be in accordance with the experimental result, proving the FEM to be effective. A coupled artificial neural networks (ANN) and finite element method technique was developed to simulate and predict springback responses to changes in the processing parameters. A particle swarm optimization (PSO) algorithm was used to optimize the weights and thresholds of the neural network model. The neural network was trained using available FEM simulation data. The results showed that a more accurate prediction of s!oringback can be acquired using the FEM-PSONN model. 展开更多
关键词 incremental sheet forming (ISF) springback prediction finite element method (FEM) artificial neural network (ANN) particle swarm optimization (PSO) algorithm
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Variation of SPAD values in uneven-aged leaves of different dominant species in Castanopsis carlessi forest in Lingshishan National Forest Park 被引量:3
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作者 王英姿 洪伟 +4 位作者 吴承祯 林晗 范海兰 陈灿 李键 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第4期362-366,I0007,共6页
The greenness (SPAD) of uneven-aged leaves of dominant species in the Castanopsis carlessi forest at different altitude gradients in Lingshishan National Forest Park, Fujian Province, China were measured by using po... The greenness (SPAD) of uneven-aged leaves of dominant species in the Castanopsis carlessi forest at different altitude gradients in Lingshishan National Forest Park, Fujian Province, China were measured by using portable chlorophyll meter SPAD-502. In addition, the correlation between SPAD value and the concentration of chlorophyll and foliar nitrogen was also investigated. Significant variations in SPAD values were found between the uneven-aged leaves of different dominant species and different altitude gradients. Regression analysis showed that SPAD value was significantly correlated with the concentration of chlorophyll and the content of foliar nitrogen, indicating that SPAD value could be indicators for foliar chlorophyll and nitrogen. It is suggested that SPAD meter is a useful tool for forest assessments in decision-making and operational nutrient management programs. 展开更多
关键词 Castanopsis carlessi forest chlorophyll content chlorophyll meter dominant population forest nutrient of nitrogen Lingshishan specific leaf area
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The group search-based parallel algorithm for the serial Monte Carlo inversion method 被引量:3
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作者 魏超 李小凡 郑晓东 《Applied Geophysics》 SCIE CSCD 2010年第2期127-134,193,共9页
With the development of parallel computing technology,non-linear inversion calculation efficiency has been improving.However,for single-point search-based non-linear inversion methods,the implementation of parallel al... With the development of parallel computing technology,non-linear inversion calculation efficiency has been improving.However,for single-point search-based non-linear inversion methods,the implementation of parallel algorithms is a difficult issue.We introduce the idea of group search to the single-point search-based non-linear inversion algorithm, taking the quantum Monte Carlo method as an example for two-dimensional seismic wave velocity inversion and practical impedance inversion and test the calculation efficiency of using different node numbers.The results show the parallel algorithm in theoretical and practical data inversion is feasible and effective.The parallel algorithm has good versatility. The algorithm efficiency increases with increasing node numbers but the algorithm efficiency rate of increase gradually decreases as the node numbers increase. 展开更多
关键词 non-linear inversion single-point search group search parallel computation
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Improved ant colony optimization for multi-depot heterogeneous vehicle routing problem with soft time windows 被引量:10
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作者 汤雅连 蔡延光 杨期江 《Journal of Southeast University(English Edition)》 EI CAS 2015年第1期94-99,共6页
Considering that the vehicle routing problem (VRP) with many extended features is widely used in actual life, such as multi-depot, heterogeneous types of vehicles, customer service priority and time windows etc., a ... Considering that the vehicle routing problem (VRP) with many extended features is widely used in actual life, such as multi-depot, heterogeneous types of vehicles, customer service priority and time windows etc., a mathematical model for multi-depot heterogeneous vehicle routing problem with soft time windows (MDHVRPSTW) is established. An improved ant colony optimization (IACO) is proposed for solving this model. First, MDHVRPSTW is transferred into different groups according to the nearest principle, and then the initial route is constructed by the scanning algorithm (SA). Secondly, genetic operators are introduced, and crossover probability and mutation probability are adaptively adjusted in order to improve the global search ability of the algorithm. Moreover, the smooth mechanism is used to improve the performance of the ant colony optimization (ACO). Finally, the 3-opt strategy is used to improve the local search ability. The proposed IACO was tested on three new instances that were generated randomly. The experimental results show that IACO is superior to the other three existing algorithms in terms of convergence speed and solution quality. Thus, the proposed method is effective and feasible, and the proposed model is meaningful. 展开更多
关键词 vehicle routing problem soft time window improved ant colony optimization customer service priority genetic algorithm
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