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Screening of Preprocessing Method of Biolog for Soil Microbial Community Functional Diversity 被引量:2
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作者 党雯 郜春花 +4 位作者 张强 李建华 卢朝东 靳东升 卢晋晶 《Agricultural Science & Technology》 CAS 2015年第10期2247-2251,2255,共6页
As one of the main methods of microbial community functional diversity measurement, biolog method was favored by many researchers for its simple oper- ation, high sensitivity, strong resolution and rich data. But the ... As one of the main methods of microbial community functional diversity measurement, biolog method was favored by many researchers for its simple oper- ation, high sensitivity, strong resolution and rich data. But the preprocessing meth- ods reported in the literatures were not the same. In order to screen the best pre- processing method, this paper took three typical treatments to explore the effect of different preprocessing methods on soil microbial community functional diversity. The results showed that, method B's overall trend of AWCD values was better than A and C's. Method B's microbial utilization of six carbon sources was higher, and the result was relatively stable. The Simpson index, Shannon richness index and Car- bon source utilization richness index of the two treatments were B〉C〉A, while the Mclntosh index and Shannon evenness were not very stable, but the difference of variance analysis was not significant, and the method B was always with a smallest variance. Method B's principal component analysis was better than A and C's. In a word, the method using 250 r/min shaking for 30 minutes and cultivating at 28 ℃ was the best one, because it was simple, convenient, and with good repeatability. 展开更多
关键词 Biolog method Preprocessing method Soil microbial community Func- tional diversity AWCD values
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Real-time flood forecasting of Huai River with flood diversion and retarding areas 被引量:6
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作者 Li Zhijia Bao Hongjun +2 位作者 Xue Cangsheng Hu Yuzhong Fang Hong 《Water Science and Engineering》 EI CAS 2008年第2期10-24,共15页
A combination of the rainfall-runoff module of the Xin’anjiang model, the Muskingum routing method, the water stage simulating hydrologic method, the diffusion wave nonlinear water stage method, and the real-time err... A combination of the rainfall-runoff module of the Xin’anjiang model, the Muskingum routing method, the water stage simulating hydrologic method, the diffusion wave nonlinear water stage method, and the real-time error correction method is applied to the real-time flood forecasting and regulation of the Huai River with flood diversion and retarding areas. The Xin’anjiang model is used to forecast the flood discharge hydrograph of the upstream and tributary. The flood routing of the main channel and flood diversion areas is based on the Muskingum method. The water stage of the downstream boundary condition is calculated with the water stage simulating hydrologic method and the water stages of each cross section are calculated from downstream to upstream with the diffusion wave nonlinear water stage method. The input flood discharge hydrograph from the main channel to the flood diversion area is estimated with the fixed split ratio of the main channel discharge. The flood flow inside the flood retarding area is calculated as a reservoir with the water balance method. The faded-memory forgetting factor least square of error series is used as the real-time error correction method for forecasting discharge and water stage. As an example, the combined models were applied to flood forecasting and regulation of the upper reaches of the Huai River above Lutaizi during the 2007 flood season. The forecast achieves a high accuracy and the results show that the combined models provide a scientific way of flood forecasting and regulation for a complex watershed with flood diversion and retarding areas. 展开更多
关键词 flood forecasting and regulation Xin’anjiang model Muskingum method water stage simulating hydrologic method diffusion wave nonlinear water stage method flood diversion and retarding area Huai River
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Rock mechanical problems and optimization for the long and deep diversion tunnels at Jinping Ⅱ hydropower station 被引量:5
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作者 Shiyong Wu Ge Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2011年第4期314-328,共15页
According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimize... According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimized to ensure construction safety. New drainage tunnels were considered. Furthermore, lining structures and grouting pressures were modified during the excavation of tunnels. The construction scheme was updated dynamically based on the complex geological conditions. For instances, the diversion tunnels were first excavated by drilling and blasting method at the first stage of construction, and then by the combination method of tunnel boring machine (TBM) and drilling and blasting, and finally by drilling and blasting method. Through optimized scheme and updated construction scheme, the excavation of diversion tunnel #1 was successfully completed in June, 2011. This paper summarizes the key issues in rock mechanics associated with the construction of the long and deep diversion tunnels at Jinping II hydropower station. The experiences of design and construction obtained from this project could provide reference to similar projects. 展开更多
关键词 Jinping II hydropower station diversion tunnels optimized design construction method GROUTING
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Weaning methods affect ruminal methanogenic archaea composition and diversity in Holstein calves 被引量:4
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作者 DONG Li-feng MA Jun-nan +1 位作者 TU Yan DIAO Qi-yu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第5期1080-1092,共13页
The objective of the present study was to examine the effect of different weaning methods on the ruminal methanogenic archaea composition and diversity in Holstein calves.Thirty-six newborn Holstein bull calves were a... The objective of the present study was to examine the effect of different weaning methods on the ruminal methanogenic archaea composition and diversity in Holstein calves.Thirty-six newborn Holstein bull calves were assigned to 1 of 3 treatments:(1)conventional weaning(d 56)and fed a high proportion of solid feed(CWS);(2)conventional weaning(d 56)and fed a high proportion of liquid feed(CWL);(3)early weaning(d 42)and fed with a high proportion of solid feed(EWS).High-throughput sequencing of the methyl coenzyme M reductase(mcr A)gene,which encodes theα-subunit of methyl coenzyme M reductase-the enzyme that catalyzes the final step in methanogenesis was used to determine the composition and diversity of rumen methanogens.No significant difference(P>0.05)was observed for operational taxonomic units(OTUs)or richness indices,but diversity indices increased(P<0.05)for calves fed high dietary solids.Predominant families across the three treatments were Methanobacteriaceae,Thermoplasmataceae and Methanomassiliicoccaceae.Calves in the EWS treatment had a higher(P<0.05)relative abundance of Methanobrevibacter sp.strain AbM4 and Methanosphaera stadtmanae,while calves in the CWL treatment had a higher(P<0.05)abundance of Methanosphaera sp.strain SM9.A positive(P<0.05)relationship was identified between butyrate and Methanobrevibacter sp.strain AbM4.In conclusion,the composition and diversity of methanogens in the rumen of Holstein calves varied under the different weaning methods.This study identified a positive relationship between butyrate and Methanobrevibacter sp.strain AbM4,potentially reflecting correlations between ruminal fermentation variables and methanogenesis function.These in-depth analyses provide further understanding of weaning methods for intensified production systems. 展开更多
关键词 calf methyl COENZYME M reductase(mcrA)gene METHANOGENIC archaea diversITY rumen fermentation WEANING methodS
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Geometric interpretation of several classical iterative methods for linear system of equations and diverse relaxation parameter of the SOR method 被引量:2
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作者 LU Xing-jiang LEI Lai-i 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2013年第3期269-278,共10页
Two kinds of iterative methods are designed to solve the linear system of equations, we obtain a new interpretation in terms of a geometric concept. Therefore, we have a better insight into the essence of the iterativ... Two kinds of iterative methods are designed to solve the linear system of equations, we obtain a new interpretation in terms of a geometric concept. Therefore, we have a better insight into the essence of the iterative methods and provide a reference for further study and design. Finally, a new iterative method is designed named as the diverse relaxation parameter of the SOR method which, in particular, demonstrates the geometric characteristics. Many examples prove that the method is quite effective. 展开更多
关键词 linear equation iterative method geometric explanation diverse relaxation parameter SORmethod.
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Penalty model for delay of bidding section construction period in South-to-North Water Diversion Eastern Route Project from perspective of programs 被引量:2
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作者 Jing-chun FENG Ya-fang REN +2 位作者 Zhong-nan DUAN Zhan-jun LIU Hai-yang LI 《Water Science and Engineering》 EI CAS 2012年第3期350-360,共11页
According to the multi-project and program management theory, this paper analyzes the program generation principle and establishes a program based on progress goals. On the basis of the present situation of calculatio... According to the multi-project and program management theory, this paper analyzes the program generation principle and establishes a program based on progress goals. On the basis of the present situation of calculation of penalty for delay of the bidding section construction period with the critical path method, we studied the effects of contractor-induced delay of the bidding section construction period in detail, including the effects on the construction period of the bidding section itself, the earliest start times of the next bidding section and other subsequent bidding sections, and the construction period of the program, and then constructed a penalty model for delay of the bidding section construction period from the perspective of programs. Using the penalty model, we conducted a practical analysis of penalty for delay of the construction period of the Baoying station program in the South-to-North Water Diversion Project. The model can help determine the amount of penalty for delay of the construction period in bidding sections scientifically and reasonably, 展开更多
关键词 program establishment program management bidding section construction period critical path method (CPM) penaly model South-to-North Water diversion Project
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Analysis on the Structure of Influencing Factors of Sustainable Supply Chain Implementation of Water Diversion Project 被引量:3
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作者 Meng Liu Liwei Yang Tongsheng Liu 《Journal of Geoscience and Environment Protection》 2021年第8期140-150,共11页
The systematic analysis of the hierarchical relationship among the factors affecting the sustainable supply chain implementation of water diversion projects has theoretical value and practical significance for the sus... The systematic analysis of the hierarchical relationship among the factors affecting the sustainable supply chain implementation of water diversion projects has theoretical value and practical significance for the sustainable development of large-scale water diversion projects. Through the investigation of relevant literature, books, web pages, materials, and discussions with relevant experts and scholars, a total of 23 factors influencing the sustainable supply chain implementation of water diversion projects were identified. Then using ISM (Interpretative Structural Modeling Method) to analyze the causality of each factor, a multi-level hierarchical structure model was obtained. The results showed that: 1) The surface-level influencing factors of the sustaina<span>ble supply chain implementation of the water diversion project mainly i</span>ncluded 8 factors such as water-saving awareness and water-saving intensity in the diversion area, water quality, water pollution and other disasters, effective incentive mechanisms, etc., and surface-level influencing factors were directly related to the sustainable supply chain implementation of water diversio<span>n projects. 2) The indirect influencing factors of the sustainable supply chai</span>n of water diversion projects included 12 factors such as the water quality and quantity guarantee rate of the supply chain, the government’s enforcement of laws and regulations, water distribution, ecological compensation, and compensatio<span>n mechanisms for residents in the water source area. Indirect influencing</span> factor scan acts directly on the direct influencing factors, and int<span>ervening in the factors that can be controlled by humans is one of the important ways to improve the sustainable operation of water diversion proj</span><span>e</span><span>cts. 3) T</span><span>he fundamental influencing factors for the sustainable supply chain implementation of water diversion projects included three f</span>actors: Resettlement policy, government financial support, and sound laws and regulations. Deep influencing factors had multi-channel influence and controllability, and intervening in them was the main means to improve the sustainable operation of water diversion projects. 展开更多
关键词 Water diversion Project Sustainable Supply Chain Interpretative Structural Modelling method Hierarchical Structure Model
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Diverse Teaching Methods of Modem University Teachers
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作者 Yuling Zhao Zhuo Zhang Ruike Cui 《International Journal of Technology Management》 2013年第11期1-2,共2页
With the rapid development of modem teaching technology, teaching equipment in university has been greatly changed. Some university classrooms have been equipped with modem multimedia classrooms, computers, printers, ... With the rapid development of modem teaching technology, teaching equipment in university has been greatly changed. Some university classrooms have been equipped with modem multimedia classrooms, computers, printers, scanners, recorders, projectors, digital cameras and other advanced electrical teaching equipment; which encourage teachers to collect and accumulate example materials and make auxiliary teaching of multimedia courseware. The teaching methods of pictures, texts, sound, dynamics and colors make the original boring teaching content, which is difficult to understand, become intuitive, vivid and easy to understand. It promotes students' positive thinking and stimulates students' potential, so as to greatly improve students' leaming enthusiasm. 展开更多
关键词 teaching methods diverse stimulate POTENTIAL
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Diverse AdaBoost-SVM分类方法及其在航空发动机故障诊断中的应用 被引量:5
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作者 胡金海 谢寿生 +2 位作者 蔡开龙 何秀然 彭靖波 《航空学报》 EI CAS CSCD 北大核心 2007年第5期1085-1090,共6页
提出采用考虑到精度/差异权衡的SVM作为弱分类器的一种新的组合分类诊断方法——DiverseAdaBoost-SVM。该方法通过在一组具有适当精度的弱分类器中进一步选择具有较大差异性的弱分类器,对这些具有较大差异性的弱分类器进行组合,从而较... 提出采用考虑到精度/差异权衡的SVM作为弱分类器的一种新的组合分类诊断方法——DiverseAdaBoost-SVM。该方法通过在一组具有适当精度的弱分类器中进一步选择具有较大差异性的弱分类器,对这些具有较大差异性的弱分类器进行组合,从而较好解决AdaBoost算法中存在的精度/差异权衡的难题;同时该方法也较好地解决了现有的AdaBoost方法存在的弱分类器本身参数选取困难问题及训练轮数T的合理选取问题。通过对基准数据库的测试及航空发动机故障样本的诊断,结果表明和其他方法相比,DiverseAdaBoost-SVM方法具有更好的泛化性能,更适合对分散程度较大、聚类性较差的航空发动机故障样本进行分类,也更适合对非对称故障样本集进行分类。 展开更多
关键词 航空发动机 故障诊断 组合分类方法 ADABOOST算法 精度/差异 支持向量机
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Effects of cultivation of Osr HSA transgenic rice on functional diversity of microbial communities in the soil rhizosphere 被引量:4
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作者 Xiaobing Zhang Xujing Wang +6 位作者 Qiaoling Tang Ning Li Peilei Liu Yufeng Dong Weimin Pang Jiangtao Yang Zhixing Wang 《The Crop Journal》 SCIE CAS CSCD 2015年第2期163-167,共5页
With the widespread cultivation of transgenic crops, there is increasing concern about unintended effects of these crops on soil environmental quality. In this study, we used the Biolog method and ELISA to evaluate th... With the widespread cultivation of transgenic crops, there is increasing concern about unintended effects of these crops on soil environmental quality. In this study, we used the Biolog method and ELISA to evaluate the possible effects of Osr HSA transgenic rice on soil microbial utilization of carbon substrates under field conditions. There were no significant differences in average well-color development(AWCD) values, Shannon–Wiener diversity index(H), Simpson dominance indices(D) and Shannon–Wiener evenness indices(E) of microbial communities in rhizosphere soils at eight samplings between Osr HSA transgenic rice and its non-transgenic counterpart. The main carbon sources utilized by soil microbes were carbohydrates, carboxylic acids, amino acids and polymers. The types,capacities and patterns of carbon source utilization by microbial communities in rhizosphere soils were similar throughout the detection period. We detected no Osr HSA protein in the roots of Osr HSA transgenic rice. We concluded that Osr HSA transgenic rice and the r HSA protein it produced did not alter the functional diversity of microbial communities in the rhizosphere. 展开更多
关键词 BIOLOG method ELISA SOIL microbes Functional diversity
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Species Diversity and Elevational Distribution of Amphibians in the Xianxialing and Wuyishan Mountain Ranges,Southeastern China 被引量:2
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作者 Zhiqiang CHEN Yun TANG +3 位作者 Yingying WANG Yindie LI Longhui LIN Guohua DING 《Asian Herpetological Research》 SCIE CSCD 2020年第1期44-55,共12页
The species diversity and altitudinal distribution of amphibians along an eleva tional gradient of 200-1600 m in the Xianxialing and Wuyishan Mountain Ranges in Southeastern China were investiga ted through time-const... The species diversity and altitudinal distribution of amphibians along an eleva tional gradient of 200-1600 m in the Xianxialing and Wuyishan Mountain Ranges in Southeastern China were investiga ted through time-constra ined visual surveys along 32 transect lines in 9 survey areas,in which the ha bitat types were also recorded.A total of 27 amphibian species belonging to 19 genera,7 families,and 2 orders were found.The species diversity of the amphibians plateaued at low elevation,and the altitudinal boundary of their distribution was at 800 m.Their species compositions were dissimilar in the two mountain ranges probably beca use the annual average temperature and annual rainfall were different in both areas.The eleva tional Rapoport's rule demonstrated that the species range size of the amphibians expanded as the elevation increased in both mountain ranges.The results of the cross species method supported the rule only when the influence of the low-frequency occurrence proba bility of an investigated species was excluded,whereas those of the Steven's method strongly corroborated the rule rega rdless of the incidental occurrence or absence of the species. 展开更多
关键词 AMPHIBIAN diversity altitudinal DISTRIBUTION Rapoport’s rule CROSS-SPECIES method Steven’s method
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Responses of bacterial community to potential heap construction methods of fine-grained copper tailings in column bioleaching system 被引量:2
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作者 Xiao-dong HAO Xue-duan LIU +8 位作者 Ping ZHU Yi-li LIANG Guan-zhou QIU Hong-qing MA Yan LIU Qian-jin LIU Li-ying REN Emmanuel Konadu SARKODIE Hong-wei LIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第6期1796-1805,共10页
The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM)... The column bioleaching of copper flotation tailings was comparatively investigated using layered heap construction method(LM),agglomerate heap construction method(AM),and pellets-sintering heap construction method(PM).The bacterial communities of free,attached,weakly-attached,and strongly-attached microbes in the later bioleaching stage were investigated.In AM group,the addition of lump sulphide ore resulted in the low leachate pH,high ferric iron concentration,and rapid microbial adsorption,which obtained the maximum copper extraction(60.1%)compared with LM(54.6%)and PM(43.9%)groups.The relative abundance of dominant genera and microbial communities of different microbiota underwent changes in three heap construction methods.The alpha-diversity indexes of attached,weakly-attached,and strongly-attached microbes were different,while no significant change was observed in free bacteria.The variation of whole bacterial community was significantly associated with solution pH,total iron,and ferric iron concentrations.Pearson correlation analysis and partial least square path model both indicated that attached bacteria made larger contribution to the copper extraction of tailings. 展开更多
关键词 fine-grained tailings column bioleaching heap construction method free and attached bacteria microbial diversity
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Performance comparison of different microbial DNA extraction methods on bird feces 被引量:1
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作者 Xian Hou Shengkai Pan +2 位作者 Zhenzhen Lin Jiliang Xu Xiangjiang Zhan 《Avian Research》 CSCD 2021年第2期247-254,共8页
Background:As an important player during food digestion,gut microbiota has attracted much attention in diet adaptation studies in birds.Microbiota extracted from feces has been widely used as a proxy for gut microbiot... Background:As an important player during food digestion,gut microbiota has attracted much attention in diet adaptation studies in birds.Microbiota extracted from feces has been widely used as a proxy for gut microbiota.Although several methods have been developed for microbial DNA extraction,their performances in the bird feces have not been systematacially evaluated yet.Methods:In this study,we applied three DNA extraction methods(Qiagen,MoBio and Bead)to extract DNA from feces of three avian dietary guilds(granivore,omnivore and carnivore),sequenced V4 region of 16S rRNA gene for each extract and evaluated the performances of DNA yield,DNA integrity,microbial composition,cell lysis capacity and alpha diversity for the three methods on each dietary guild.Results:Bead method was the best on the performance of both DNA yield and DNA integrity regardless of dietary guild.In granivore,microbial relative abundance at both species and phylum levels,alpha diversity and cell lysis capacity were comparable among all methods.In omnivore,Qiagen had the best performance on alpha diversity,fol-lowed by Bead and MoBio.There were small variations on microbial relative abundance at both species and phylum levels among different extraction methods.MoBio exhibited the best performance on cell lysis capacity.In carnivore,considerable variations were found on microbial relative abundance at both species and phylum levels.Qiagen had the best performance on alpha diversity,followed by MoBio and Bead.MoBio had the highest cell lysis capacity.Conclusions:DNA yield and integrity have no obvious impact on microbial composition,alpha diversity or cell lysis capacity.The microbiota results(e.g.,microbial composition,cell lysis capacity,alpha diversity)obtained from differ-ent methods are comparable in granivorous avian species but not in omnivorous or carnivorous birds.Either method could be used in granivore microbiota studies.For omnivores and carnivores,we recommend Qiagen method when the research purpose is microbial diversity and MoBio when gram-positive bacteria is the research target. 展开更多
关键词 16S rRNA Alpha diversity AVIAN Dietary guild FECES DNA extraction method Microbial relative abundance
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Extending Dynamic Range of Phase Diversity
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作者 王欣 赵达尊 《Journal of Beijing Institute of Technology》 EI CAS 2010年第3期348-352,共5页
A method for extending dynamic range of phase diversity (PD) is proposed.The estimating of pupil phase is divided into two steps.Low-order Zernike coefficients of the phase are estimated firstly before all of the Ze... A method for extending dynamic range of phase diversity (PD) is proposed.The estimating of pupil phase is divided into two steps.Low-order Zernike coefficients of the phase are estimated firstly before all of the Zernike coefficients estimated.The method is based on the assumption that the aberrations of the system are dominated by low order Zernike modes,which is true to most practical situations.The algorithm of BroydenFletcher-Goldfarb-Shanno(BFGS) is used in the two steps for optimizing process.Computer simulations are conducted after the theoretical analysis.The result shows that this method can effectively avoid the trap in local minimum during iteration process,and the dynamic range that PD can detect extends from about 2λ to about 4λ. 展开更多
关键词 phase diversity wave-front sensing Zernike coefficients two-step method
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Bayesian Estimation of Shrubs Diversity in Rangelands under Two Management Systems in Northern Syria
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作者 Abdoul Aziz Niane Murari Singh Paul C. Struik 《Open Journal of Ecology》 2014年第4期168-173,共6页
The diversity of shrubs in rangelands of northern Syria is affected by the grazing management systems restricted by the increase in human and livestock populations. To describe and estimate diversity and compare the r... The diversity of shrubs in rangelands of northern Syria is affected by the grazing management systems restricted by the increase in human and livestock populations. To describe and estimate diversity and compare the rangeland grazing management treatments, two popular indices for diversity, the Shannon index and the Simpson index, were studied for the four combinations of two sites, Hammam and Obeisan, and two grazing methods, Closed and Open, using frequentist and Bayesian approaches. We simulated the a priori and a-posteriori distributions of the Shannon and Simpson diversity indices, where from a range of values for a constant in the a priori distribution the best value normalizing the distribution of the diversity indices was chosen. The Bayesian diversity estimates were higher than their frequentist counterparts and had lower standard errors. The grazing methods at each site and sites under each grazing method delivered significant diversity of shrub species. The Bayesian estimates resulted in lower p-values than the frequentist approach for two cases reflecting in Bayesian method’s higher power. Bayesian approach is recommended as it has a wider framework for inference on diversity studies. 展开更多
关键词 Arid RANGELANDS Species Abundance diversITY Shannon INDEX SIMPSON diversITY INDEX Bayesian method
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"Three-Component" Digital Prospecting Method: A New Approach for Mineral Resources Quantitative Prediction and Assessment
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作者 ZhaoPengda ChenJianping +2 位作者 ChenJianguo ZhangShouting ChenYongqing 《Journal of China University of Geosciences》 SCIE CSCD 2004年第3期245-252,共8页
Three-component' method consists of three close-connected aspects: geological anomaly, diversity of mineralization and mineral deposit spectrum. All these three concepts are not new separately, but it is a new app... Three-component' method consists of three close-connected aspects: geological anomaly, diversity of mineralization and mineral deposit spectrum. All these three concepts are not new separately, but it is a new approach to combine these three aspects in one single concept for quantitative mineral resources prediction and assessment and it is also the first time to conduct a more detailed study in each aspect. Investigation and clarification of geological anomalies, diversity of mineralization and spectrum of mineral deposits are realized by digitization and quantification of ore forming controlling factors, ore-existing symbols or marks, characteristics of mineralization and regulation of ore-genesis and laws of distribution. These procedures lead to construction of a 'digital model' for mineral resources prediction and assessment. 展开更多
关键词 three-component' method geological anomaly diversity of mineralization spectrum of mineral deposits.
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Determination of Critical Slip Surface of Soil Slope by New Complex Method
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作者 李亮 迟世春 林皋 《Journal of Southwest Jiaotong University(English Edition)》 2006年第2期165-170,共6页
A new complex method is presented considering not only the improvement upon the "bad "design point, but also the diversity of the newly generated complex, which is obtained by replacing the "bad "design point with... A new complex method is presented considering not only the improvement upon the "bad "design point, but also the diversity of the newly generated complex, which is obtained by replacing the "bad "design point with the better design point located at the line between the "bad "design point and the ceotroid of the remaining design points of the old complex. The new complex method is applied to searching for the critical slip surface of two non-homogeneous soil slopes. The comparison of the results obtained by the new complex method with that by the basic complex method shows that the new complex method is much more likely to find the true critical surface for the randomly generated initial complex. 展开更多
关键词 Slope stability mudysis Safety factor Complex method diversITY
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BLIND CHANNEL ESTIMATION IN DELAY DIVERSITY FOR FREQUENCY SELECTIVE CHANNELS
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作者 ZhaoZheng JiaYing YinQinye 《Journal of Electronics(China)》 2003年第5期326-336,共11页
Delay diversity is an effective transmit diversity technique to combat adverse effects of fading. Thus far, previous work in delay diversity assumed that perfect estimates of current channel fading conditions are ava... Delay diversity is an effective transmit diversity technique to combat adverse effects of fading. Thus far, previous work in delay diversity assumed that perfect estimates of current channel fading conditions are available at the receiver and training symbols are required to estimate the channel from the transmitter to the receiver. However, increasing the number of the antennas increases the required training interval and reduces the available time with in whichdata may be transmitted. Learning the channel coefficients becomes increasingly difficult for the frequency selective channels. In this paper, with the subspace method and the delay character of delay diversity, a channel estimation method is proposed, which does not use training symbols. It addresses the transmit diversity for a frequency selective channel from a single carrier perspective in the form of a simple equivalent flat fading model. Monte Carlo simulations give the performance of channel estimation and the performance comparison of our channel-estimation-based detector with decision feedback equalization, which uses the perfect channel information. 展开更多
关键词 Delay diversity Subspace method Blind channel estimation Frequency selective channels Array signal processing
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间作黄芪对当归根际土壤微生物的影响 被引量:2
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作者 李媛媛 谢丰璞 +8 位作者 王楠 高静 黄文静 李铂 孙晓春 宋忠兴 唐志书 王二欢 马存德 《中国野生植物资源》 CSCD 2024年第1期79-86,92,共9页
目的:探讨根际土壤微生物对中药材种植模式的响应方式。方法:以间作黄芪及单作下当归根际土壤为研究对象,基于高通量测序技术,分析土壤微生物在不同季节及种植模式下群落组成及功能的差异。结果:间作下Chao1指数、ACE指数高于单作,变形... 目的:探讨根际土壤微生物对中药材种植模式的响应方式。方法:以间作黄芪及单作下当归根际土壤为研究对象,基于高通量测序技术,分析土壤微生物在不同季节及种植模式下群落组成及功能的差异。结果:间作下Chao1指数、ACE指数高于单作,变形菌门、放线菌门、酸杆菌门、绿弯菌门和芽单胞菌门为间作下的优势菌门,芽单胞菌门的相对丰度在间作下高于单作。11月间作下γ变形菌纲、7月间作下全噬菌纲的丰度显著高于单作。KEGG功能预测表明,在不同时间及间作下根际土壤细菌与细胞过程、环境信息处理、遗传信息处理、代谢功能下属的23类二级功能基因的相对丰度存在显著差异;参与氮循环的功能基因K00371(narH/narY/nxrB)、(K00374 narI/narV)等OTU数在间作下显著高于单作;不同门、纲在间作下的共生网络比单作下连接紧密且更复杂。结论:当归间作黄芪影响土壤细菌群落组成,增加其丰富度及功能的丰富性,影响土壤氮循环能力,促进土壤微生物间的交互作用。 展开更多
关键词 土壤微生物 根际 高通量测序 多样性 种植方式
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知识复杂性的测度方法综述与比较 被引量:1
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作者 陈钰芬 胡思慧 《情报杂志》 CSSCI 北大核心 2024年第3期165-172,78,共9页
[研究目的]复杂知识是突破关键核心技术的基础支撑,也是企业或区域建立竞争优势的关键要素。该文旨在全面把握知识复杂性测度方法的研究现状与前沿进展,为知识复杂性的深入研究提供测度理论基础。[研究方法]通过梳理国内外知识复杂性研... [研究目的]复杂知识是突破关键核心技术的基础支撑,也是企业或区域建立竞争优势的关键要素。该文旨在全面把握知识复杂性测度方法的研究现状与前沿进展,为知识复杂性的深入研究提供测度理论基础。[研究方法]通过梳理国内外知识复杂性研究的相关文献,详细介绍三种主要的知识复杂性测度方法的核心思想、理论基础和计算过程,并进一步对比分析不同方法的适用层次和优缺点,最后提出未来研究方向。[研究结论]反射法主要基于知识的空间分布异质性间接衡量知识复杂性,虽然原理简单且操作相对容易,但无法揭示知识复杂性的本质特征;元素依赖性指数利用知识组合频次衡量知识元素之间的相互依赖程度,进而反映知识复杂性,忽视了其他影响知识组合的因素;结构多样性指数通过知识组合网络拓扑结构的多样性反映知识复杂性,综合考虑多个网络结构指标,并经过大量数值模拟检验,但存在估计结果不稳定、仅适用于二值网络等问题。 展开更多
关键词 知识复杂性测度 反射法 元素依赖性指数 结构多样性指数
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