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Non-Targeted Metabolomics Reveals the Metabolic Alterations in Response to Artificial Selective Breeding in the Fast-Growing Strains of Pacific Oyster
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作者 HU Boyang TIAN Yuan +1 位作者 LIU Shikai LI Qi 《Journal of Ocean University of China》 CAS CSCD 2024年第2期518-528,共11页
Pacific oyster(Crassostrea gigas)is one of the most important mollusks cultured all around the world.Selective breeding programs of Pacific oysters in China is initiated since 2006 and developed the genetically improv... Pacific oyster(Crassostrea gigas)is one of the most important mollusks cultured all around the world.Selective breeding programs of Pacific oysters in China is initiated since 2006 and developed the genetically improved strain with fast-growing trait.However,little is known about the metabolic signatures of the fast-growing trait.In the present study,the non-targeted metabolomics was performed to analyze the metabolic signatures of adductor muscle tissue in one-year old Pacific oysters from fast-growing strain and the wild population.A total of 7767 and 10174 valid peaks were extracted and quantified in ESI^(+)and ESI^(−)modes,resulting in 399 and 381 annotated metabolites,respectively.PCA and OPLS-DA revealed that considerable separation among samples from fastgrowing strain and wild population,suggesting the differences in metabolic signatures.Meanwhile,81 significantly different metabolites(SDMs)were identified in the comparisons between fast-growing strain and wild population,based on the strict thresholds.It was found that there were highly correlation and conserved coordination among these SDMs.KEGG enrichment analysis indicated that the SDMs were tightly related to pantothenate and CoA biosynthesis,steroid hormone biosynthesis,riboflavin metabolism,and arginine and proline metabolism.Of them,the CoA biosynthesis and metabolism,affected by pantetheine and pantothenic acid,might be important for the growth of Pacific oysters under artificial selective breeding.The study provides the comprehensive views of metabolic signatures in response to artificially selective breeding,and is helpful to better understand the molecular mechanism of fastgrowing traits in Pacific oysters. 展开更多
关键词 metabolic signature Pacific oyster artificial selection fast-growing trait
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Influence of Aspect Ratio on Rolling Shear Properties of Fast-Grown Small Diameter Eucalyptus Lumber 被引量:4
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作者 Tao Gui Shichen Cai +1 位作者 Zhiqiang Wang Jianhui Zhou 《Journal of Renewable Materials》 SCIE EI 2020年第9期1053-1066,共14页
Eucalyptus is a major fast-grown species in South China,which has the potential for producing structural wood products such as cross-laminated timber(CLT).Aspect ratio(board width vs.board thickness)of eucalyptus lumb... Eucalyptus is a major fast-grown species in South China,which has the potential for producing structural wood products such as cross-laminated timber(CLT).Aspect ratio(board width vs.board thickness)of eucalyptus lumbers is small due to the small diameter of fast-grown eucalyptus wood.To evaluate its rolling shear modulus and strength for potential CLT applications,three-layer hybrid CLT shear block specimens with different aspect ratios(2,4,6),were tested by planar shear test method.Digital image correlation(DIC)was employed to measure the rolling shear strain distribution and development during the planar shear tests.The mean values of rolling shear modulus and strength of eucalyptus lamination were 260.3%and 88.2%higher than those of SPF(Spruce-pine-fir)lamination with the same aspect ratio of 4,respectively.The rolling shear properties of eucalyptus laminations increased as the aspect ratio increased.Aspect ratio had a significant influence on rolling shear modulus compared to rolling shear strength.The high shear strain regions were primarily found around the gaps between segments of cross layer.The quantity of high shear strain regions increased as the aspect ratio of lamination decreased.Other high shear strain regions also occurred around the pith and along the glue line.The sudden failure of specimen occurred in the high strain region.In conclusion,the rolling shear strength and modulus of fast-grown eucalyptus laminations exceed the respective characteristic values for softwoods in the current standard by roughly factors of 3 and 8,indicating great potential for fast-grown eucalyptus wood cross-layers in CLT. 展开更多
关键词 fast-grown eucalyptus cross-laminated timber rolling shear aspect ratio digital image correlation
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Characteristics of fast-growing wood impregnated with nanoparticles 被引量:2
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作者 Istie Rahayu Wayan Darmawan +1 位作者 Lukmanul Hakim Zaini Esti Prihatini 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第2期677-685,共9页
Falcataria moluccana or sengon is one of the fast-growing wood species widely grown in Indonesia.However,its wood is low quality with low density,and poor strength,durability,and dimensional stability.This study deter... Falcataria moluccana or sengon is one of the fast-growing wood species widely grown in Indonesia.However,its wood is low quality with low density,and poor strength,durability,and dimensional stability.This study determined the effects of impregnation with monoethylene glycol(MEG)and nano-SiO2 on the characteristics of sengon wood,including its dimensional stability and density.Impregnation with MEG and nano-SiO2 had a significant effects on dimensional stability in terms of the weight percent gain,anti-swelling efficiency,water uptake,bulking effect,and density.The impregnated wood was examined by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and X-ray diffraction.The results show that MEG and nano-SiO2 were distributed homogeneously into cell walls of wood treated with 0.5%MEGSiO2. 展开更多
关键词 Falcataria moluccana fast-growing species Impregnation:monoethylene glycol NANOPARTICLES Dimensional stability
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Vacuum press drying studies on two fast-growing Indian wood species 被引量:2
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作者 Shailendra Kumar Rushikesh R.Topare Jitendra Nagar 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第3期857-862,共6页
Two fast-growing Indian species, Melia composita Benth. and Eucalyptus tereticornis Sm., which have different sets of physical properties, were dried together in a vacuum press dryer(VPD) under two drying conditions,i... Two fast-growing Indian species, Melia composita Benth. and Eucalyptus tereticornis Sm., which have different sets of physical properties, were dried together in a vacuum press dryer(VPD) under two drying conditions,i.e., above boiling point(ABP) and below boiling point(BBP). The ABP and BBP conditions were maintained by keeping the temperature constant at 75 ℃ and maintaining two pressure levels: 300 mm of Hg(ABP) and 450 mm of Hg(BBP). In order to understand pressure conditions at the core during vacuum drying, a cylindrical brass pipe was inserted in both wood cores and attached with pressure gauges placed outside of the VPD. The results indicate that the Melia wood core attained equilibrium pressure immediately with the pressure of VPD, while Eucalyptus attained it very slowly, reaching equilibrium at later stages of drying when cracks and checks advanced to the core.The drying rate was higher for Melia than Eucalyptus under both drying conditions. The drying rate of Melia(ABP) was higher than Melia(BBP), however, the drying rate for Eucalyptus(ABP) was not significantly different from the BBP drying rate. 展开更多
关键词 Vacuum press drying Melia composita eucalyptus tereticornis Boiling point Wood core pressure
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Comparison of the morphometric dynamics of fast-growing and slow-growing strains of turbot Scophthalmus maximus
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作者 王新安 马爱军 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第4期890-894,共5页
The dynamics of changes in body shape of fast-growing and slow-growing strains of turbot Scophthalmus maximus, and of the differences in body shape between the two strains, were evaluated from 3 to 27 months of age. T... The dynamics of changes in body shape of fast-growing and slow-growing strains of turbot Scophthalmus maximus, and of the differences in body shape between the two strains, were evaluated from 3 to 27 months of age. The ratios of total length/body length, body width/body length and total length/body width were used as morphometric indices. The two strains exhibited different temporal trends in total length/body length but similar trends in body width/body length and total length/body width. Generally, body width/body length of the two strains increased with time and total length/body width decreased. Thus, the bodies of both fast-growing and slow-growing strains of turbot changed from a narrow to a more rounded shape. However, the ratio total length/body length was generally lower, body width/body length was mostly higher and total length/body width was consistently lower in the fast-growing strain than in the slowgrowing strain. Correlation analysis of the three shape ratios with body weight showed that total length/body length and total length/body width were unsuitable, and that width/body length was suitable, for use as a phenotypic marker for selective breeding of turbot for growth in weight. 展开更多
关键词 Scophthalmus maximus slow-growing strain fast-growing strain morphometric comparison
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Study on Microwave Pretreatment Technology to Improve the Effect of Shellac Impregnation of Fast-Growing Chinese Fir
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作者 Xiya Yu Nianfeng Wei +4 位作者 Qisong Liu Zhiyong Wu Mizi Fan Weigang Zhao Qinzhi Zeng 《Journal of Renewable Materials》 SCIE EI 2022年第8期2041-2053,共13页
To improve the mechanical properties of fast-growing Chinese fir(Cunnighamia lanceolate),expand its range of application,increase its value,and avoid the environmental pollution caused by impregnation with synthetic r... To improve the mechanical properties of fast-growing Chinese fir(Cunnighamia lanceolate),expand its range of application,increase its value,and avoid the environmental pollution caused by impregnation with synthetic resin,Chinese fir was impregnated with a shellac solution.Since the shellac solution was difficult to penetrate into fast-growing Chinese fir,so microwave pretreatment was used to irradiate the wood to improve the permeability.This study investigated the effects of four factors,including the content of moisture in the wood before it was microwaved,the chamber pressure of microwave,the time of microwaving and the vacuum impregnation on the mechanical properties of Chinese fir wood.When the moisture content of wood before microwave was approximately 50%–60%,after microwaving and impregnation,the ultimate strength in static bending(modulus of rupture[MOR])and strength in compression perpendicular to the grain(SCPG)of the wood increased significantly.A microwave time of 100 seconds was more effective at improving the MOR and SCPG of the wood.If the wood was microwaved for too short or long period of time,the microwave pretreatment was not effective.When the samples were immersed in shellac for a longer period,the MOR and SCPG of Chinese fir gradually increased,but when the wood was impregnated for more than 12 hours,the increases were not significant.After the shellac penetrated the Chinese fir wood,it spread on the inner wall surface of tracheid to form a shellac film and easily formed plug-like deposits in microcapillaries.The use of Fourier-transform infrared spectroscopy,scanning electron microscopy and scanning electron microscopy-energy dispersion x-ray indicated that the microwave pretreatment can destroy the pit membranes on tracheids and facilitate the ability of shellac to penetrate the channel. 展开更多
关键词 fast-growing Chinese fir Microwave pretreatment SHELLAC IMPREGNATION Mechanical properties
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Determinants of foreign direct investment in fast-growing economies: evidence from the BRICS and MINT countries
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作者 Simplice Asongu Uduak S.Akpan Salisu R.Isihak 《Financial Innovation》 2018年第1期381-397,共17页
The flow of foreign direct investment(FDI)into a country can benefit both the investing entity and host government.This study employed panel analysis to examine the factors that determine the direction of FDI to the f... The flow of foreign direct investment(FDI)into a country can benefit both the investing entity and host government.This study employed panel analysis to examine the factors that determine the direction of FDI to the fast-growing BRICS(Brazil,Russia,India,China,and South Africa)and MINT(Mexico,Indonesia,Nigeria,and Turkey)countries.First,we used a pooled time-series cross sectional analysis of data from 2001 to 2011 to estimate and model the determinants of FDI for three samples:BRICS only,MINT only,and BRICS and MINT combined.Then,a fixed effects approach was employed to provide the model for BRICS and MINT combined.The results demonstrate that market size,infrastructure availability,and trade openness play the most significant roles in attracting FDI to BRICS and MINT,while the roles of availability of natural resources and institutional quality are insignificant.To sustain and promote FDI inflow,the governments of BRICS and MINT must ensure that their countries remain attractive for investment by offering a level playing field for investors and political stability.BRICS and MINT governments also need to invest more in their human capital to ensure that their economies can absorb substantial skills and technology spillovers from FDI and promote sustainable long-term economic growth.This study is significant because it contributes to the literature on determinants of FDI by extending the scope of previous studies that often focused on BRICS only. 展开更多
关键词 FDI Determinants fast-growing economies BRICS MINT
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International Practice of Fast-Growing Innovative Companies
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作者 Marina Yudenko Nadezhda Polovnikova +2 位作者 Natalya Chikisheva Natalia Meller Irina Kuzovleva 《Chinese Business Review》 2017年第10期496-503,共8页
The purpose of the article is to compare the conditions of development and support of fast-growing companies in European countries, Asian countries, and Russia. The comparative analysis performed is of interest as cer... The purpose of the article is to compare the conditions of development and support of fast-growing companies in European countries, Asian countries, and Russia. The comparative analysis performed is of interest as certain countries, including Russia, face the problem of economic slowdown. However, the fast-growing companies are powerful catalysts for the growth of the gross domestic product and the employment of the population. The conclusion of the study is that there are common patterns in ongoing support programs for fast-growing companies: long term, state support, innovative company orientation, and concessional financing. At the same time, there are fundamental differences in approaches to the state support for innovative companies. The first approach relates to the natural development of the fast-growing innovation companies and their support programs (Germany, Denmark); the second approach is aimed at artificially stimulating the growth of such companies (South Korea). In Russia there are institutional features of supporting fast-growing companies: small businesses are the most vulnerable part of the economic system and they require state support in crisis situations. Therefore, the experience of European and Asian countries in terms of supporting innovative and fast-growing companies can have a positive impact on the development of innovative companies in Russia. And definitely it is important to try to understand the nature of Russian innovative fast-growing companies: do we see them as entrepreneurial business as we do in the Western companies? 展开更多
关键词 fast-growing companies support program small businesses administrative barriers RUSSIA GAZELLE
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Date of First Thinning in a Very High-Density Eucalyptus Plantation in the Pointe-Noire Region (Republic of Congo) 被引量:1
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作者 Hugues-Yvan Gomat Chrissy Garel Makouanzi Ekomono +4 位作者 François Mankessi Alberdie Saïra Mangoubi Mantala Ulrich Mayinguidi Ruben Pambou Laurent Saint-Andre 《Open Journal of Forestry》 2024年第4期451-461,共11页
Management of the Pointe-Noire Forest requires high-performance tools for simulating tree and stand growth and assessing the sustainability of plantations. Modelling the dynamics of even-aged and mono-species stands i... Management of the Pointe-Noire Forest requires high-performance tools for simulating tree and stand growth and assessing the sustainability of plantations. Modelling the dynamics of even-aged and mono-species stands is a very active research topic. The approaches adopted by researchers vary according to the objectives and species considered: dendrometrical, Eco physiological or architectural. Thanks to the particular nature of these plantations and the trial set-up, it will be possible to explore the various aspects of production, clearly separating the part linked to genetics (three clones tested) from the part linked to the environment (via fertilisation) and the part associated with competition between trees (via planting densities and thinning regimes). This study will make a major contribution to the applicability of the self-thinning line and the RDI (Reineke Density Index) (Reineke, 1933) to fast-growing plantations. This research work will contribute to two points: 1) product diversification, which is a way of coping with international variations in timber markets, and 2) understanding how ecosystems function in exceptionally poor conditions, which will then enable the environmental impacts of the various recommended silvicultural itineraries to be assessed. The results obtained show that competition between trees in a stand of eucalyptus at very high density (10,000 stems/ha) and in two environments of very contrasting fertility is different depending on the clone. The decision on the date of the first thinning with a view to silviculture for timber and energy wood, which aims to ensure sustained and sustainable production of eucalyptus wood in these soils, should be taken between 12 and 14 months. The competition band is strong between 14 and 17 months, when the RDI = 0.8 is double that observed at 12 months. 展开更多
关键词 SILVICULTURE eucalyptus Pointe-Noire THINNING RDI
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Synthesis of plant-based biogenic jarosite nanoparticles using Azadirachta indica and Eucalyptus gunni leaf extracts and its application in Fenton degradation of dicamba
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作者 Shivaswamy Bhaskar Basavaraju Manu +1 位作者 Marikunte Yanjarappa Sreenivasa Arlapadavu Manoj 《Water Science and Engineering》 EI CAS CSCD 2024年第2期157-165,共9页
Bio-jarosite,an iron mineral synthesized biologically using bacteria,is a substitute for iron catalysts in the Fenton oxidation of organic pollutants.Iron nanocatalysts have been widely used as Fenton catalysts becaus... Bio-jarosite,an iron mineral synthesized biologically using bacteria,is a substitute for iron catalysts in the Fenton oxidation of organic pollutants.Iron nanocatalysts have been widely used as Fenton catalysts because they have a larger surface area than ordinary catalysts,are highly recyclable,and can be treated efficiently.This study aimed to explore the catalytic properties of bio-jarosite iron nanoparticles syn-thesized with green methods using two distinct plant species:Azadirachta indica and Eucalyptus gunni.The focus was on the degradation of dicamba via Fenton oxidation.The synthesized nanoparticles exhibited different particle size,shape,surface area,and chemical composition characteristics.Both particles were effective in removing dicamba,with removal efficiencies of 96.8%for A.indica bio-jarosite iron nano-particles(ABFeNPs)and 93.0%for E.gunni bio-jarosite iron nanoparticles(EBFeNPs)within 120 min of treatment.Increasing the catalyst dosage by 0.1 g/L resulted in 7.6%and 43.0%increases in the dicamba removal efficiency for EBFeNPs and ABFeNPs with rate constants of 0.025 min^(-1) and 0.023 min^(-1),respectively,confrming their catalytic roles.Additionally,the high efficiency of both catalysts was demonstrated through five consecutive cycles of linear pseudo-first-order Fenton oxidation reactions. 展开更多
关键词 Acidithiobacillus ferrooxidans Fenton process JAROSITE HERBICIDE DICAMBA Azadirachta indica eucalyptus gunni
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Genetic variation and selection of 10-year-old Eucalyptus camaldulensis based on wind damage index and wood properties
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作者 Xiuhua Shang Zhihua Wu +2 位作者 Xiaoming Li Youshuang Wang Peijian Zhang 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第6期173-184,共12页
Typhoons are becoming frequent and intense with ongoing climate change,threatening ecological security and healthy forest development in coastal areas.Eucalyptus of a predominant introduced species in southern China,f... Typhoons are becoming frequent and intense with ongoing climate change,threatening ecological security and healthy forest development in coastal areas.Eucalyptus of a predominant introduced species in southern China,faces significant growth challenges because of typhoon.Therefore,it is vital to investigate the variation of related traits and select superior breeding materials for genetic improvement.Variance,genetic parameter,and correlation analyses were carried out on wind damage indices and eight wood proper-ties in 88 families from 11 provenances of 10-year-old Euca-lyptus camaldulensis.The selection index equation was used for evaluating multiple traits and selecting superior prov-enances and family lines as future breeding material.The results show that all traits were highly significantly differ-ent at provenance and family levels,with the wind damage index having the highest coefficient of genetic variation.The heritability of each trait ranged from 0.48 to 0.87,with the wind damage index,lignin and hemicellulose contents,and microfibril angle having the highest heritabilities.The wind damage index had a positive genetic correlation with wood density,a negative correlation with lignin content,a negative phenotypic correlation and a negative genetic correlation with microfibril angle.Wind damage index and genetic progress in the selection of eight wood traits varied from 7.2%to 614.8%.Three provenances and 12 superior families were selected.The genetic gains of the wind damage index were 10.2%and 33.9%for provenances and families,and these may be starting material for genetic modification for wind resistance in eucalyptus and for their dissemination to typhoon-prone coastal areas of southern China. 展开更多
关键词 eucalyptus camaldulensis Wind damage index Wood properties Genetic variation Comprehensive selection
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Effect of Soil Fertility and Planting Density on the Partitioning of the Above-Ground Biomass of Eucalyptus in a Plantation (Pointe-Noire, Republic of Congo)
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作者 Hugues-Yvan Gomat Chrissy Garel Makouanzi-Ekomono +6 位作者 Suspense Averti Ifo Nzaba Miyouna Dulvin Ulrich Mayinguindi Ruben Pambou Florian Mézerette Philippe Santenoise Saint-Andre Laurent 《Open Journal of Ecology》 2024年第10期814-830,共17页
Afforestation and reforestation are useful approaches to improve carbon sequestration. With the advent of forest plantations, growing environment conditions have become increasingly restrictive for light, soil nutrien... Afforestation and reforestation are useful approaches to improve carbon sequestration. With the advent of forest plantations, growing environment conditions have become increasingly restrictive for light, soil nutrients, and interactions between trees to acquire available resources. Tree biomass data are essential for understanding the forest carbon cycle and plant adaptations to the environment. The distribution of tree biomass depends on the sum of multiple stand conditions. The data are from a dedicated experiment with two very contrasting areas of fertility, and two planting densities, including a high density at planting in order to achieve thinning. The plant material consists of the high-performance clones of Eucalyptus urophylla × E. grandis and the reference clone E. PF1. We hypothesize that the distribution of biomass changes as the intensity of competition changes and that this is accelerated by the fertility of the sites in time. The results indicate that fertilization, planting density and clones have an impact on biomass partitioning. 展开更多
关键词 Biomass Carbon PLANTATION eucalyptus Competition Effect Soil Fertility
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What Is the Impact of Ploughing on Eucalyptus Plantations in Bambou Mingali (Plateaux Batéké, Republic of Congo)?
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作者 Hugues-Yvan Gomat Darius Martin Bengo +5 位作者 Suspense Averti Ifo François Mankessi Josias Ossendza Prosper Mabiala Bernhard Zeller Laurent Saint-Andre 《Agricultural Sciences》 2024年第10期1132-1146,共15页
Soil ploughing is an important stage in the preparation of planting, causing disturbance to the physical, chemical and biological properties of the soil. Soil ploughing can affect the availability of nutrients and wat... Soil ploughing is an important stage in the preparation of planting, causing disturbance to the physical, chemical and biological properties of the soil. Soil ploughing can affect the availability of nutrients and water resources, and its effect can be short, medium or long-term. Soil ploughing accelerates surface heating and air circulation and encourages mineralisation by transforming organic matter into mineral salts, making nutrients soluble and accessible to plants. The aim of this study is to determine how soil ploughing affects the distribution of nutrients in the soil profile. The study focuses on nitrogen, carbon, phosphorus, calcium and magnesium, which are major elements of soil fertility on the Batéké plateaux in Congo. The results indicate that ploughing significantly modifies the distribution at depth des elements nutritifs: there is more accumulation at the surface than at depth (ei: nitrogen 1.34 t/ha ± 0.035 at 10 cm compared with 1.034 t/ha ± 0.098 at 50 cm) with a higher concentration of carbon (13.89 t/ha ± 0.87) followed by nitrogen (1.34 t/ha ± 0.035). 展开更多
关键词 PLOUGHING MINERALIZATION eucalyptus Plateaux Batéké CONGO
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Single leaf area estimation models based on leaf weight of eucalyptus in southern China 被引量:8
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作者 刁军 雷相东 +2 位作者 洪玲霞 戎建涛 石强 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第1期73-76,I0003,共5页
Leaf area is an important parameter for modeling tree growth and physiological processes of trees. The single young and mature leaf area estimation models of eucalyptus were developed based on leaf fresh weight. In to... Leaf area is an important parameter for modeling tree growth and physiological processes of trees. The single young and mature leaf area estimation models of eucalyptus were developed based on leaf fresh weight. In total, leaf area and leaf weight were measured from 455 fresh leaves of 25 trees of eucalyptus in southern China. The majority of the data (80%) were used for model calibration, and the remaining data (20%) were used for model validation. The linear, compound and power models were tested. Based on goodness of fit, prediction ability and residual performance, we found that linear and power models could best describe the relationship between leaf area and weight for young leaf and mature leaf, respectively. The study provides a simple and reliable method for estimating single-leaf area, which has a good potential in the functional- structural model of eucalyptus. 展开更多
关键词 eucalyptus leaf area leaf weight allometric model
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巨桉(Eucalyptus grandis)人工林土壤动物群落对采伐干扰的初期响应 被引量:22
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作者 肖玖金 张健 +4 位作者 杨万勤 黄玉梅 杨鲁 李纪伟 严妲 《生态学报》 CAS CSCD 北大核心 2008年第9期4531-4539,共9页
为了解采伐干扰对巨桉(Eucalyptus grandis)人工林土壤动物的影响,于2005~2007年采用手捡法和干湿漏斗法对四川省洪雅县巨桉人工林采伐干扰前和采伐干扰后土壤动物群落进行调查,采伐干扰前四季共获土壤动物4775头,分属4门11纲27目,... 为了解采伐干扰对巨桉(Eucalyptus grandis)人工林土壤动物的影响,于2005~2007年采用手捡法和干湿漏斗法对四川省洪雅县巨桉人工林采伐干扰前和采伐干扰后土壤动物群落进行调查,采伐干扰前四季共获土壤动物4775头,分属4门11纲27目,采伐干扰后获土壤动物4640头,分属4门10纲23目。采伐干扰后秋季(10月)、冬季(1月)和春季(4月)土壤动物个体数较采伐干扰前分别上升224头、368头和443头,而夏季(7月)下降了1170头。采伐干扰前巨桉人工林土壤动物个体数与类群数季节变化趋势基本一致,而采伐干扰后土壤动物类群数变化受土壤动物个体数变化的影响较小。与采伐干扰前相比,采伐干扰后枯落物层各季节土壤动物密度均低于采伐前,0~5 cm土层土壤动物密度与干扰前呈相反的变化趋势,其波动较5~10 cm和10~15 cm土层大。采伐干扰后土壤动物类群数四季共减少4个,采伐干扰前后土壤动物优势类群类群数波动小,采伐后常见类群类群数上升(除冬季外),稀有类群对采伐干扰较敏感,其类群数下降幅度较大。采伐干扰前后同功能种团均以杂食性和腐食性土壤动物为主,两者百分比之和均在89%以上。密度-类群指数(DG)和多样性指数(H′)的变化趋势相似,采伐干扰前后的变化趋势相反,表明采伐干扰对巨桉人工林土壤动物季节变化有较大影响。 展开更多
关键词 采伐干扰 巨桉(eucalyptus grandis)人工林 土壤动物 群落
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Radial Variation in Sap Flux Density as a Function of Sapwood Thickness in Two Eucalyptus ( Eucalyptus urophylla ) Plantations 被引量:9
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作者 周国逸 黄志宏 +4 位作者 Jim MORRIS 李志安 John COLLOPY 张宁南 白嘉雨 《Acta Botanica Sinica》 CSCD 2002年第12期1418-1424,共7页
Radial variation in sap flux density (SFD) as a function of sapwood thickness is of importance in accurately estimating sap flux through sapwood area which, in turn, decides the precision of heat pulse application. Ho... Radial variation in sap flux density (SFD) as a function of sapwood thickness is of importance in accurately estimating sap flux through sapwood area which, in turn, decides the precision of heat pulse application. However, until now, only a few studies have evaluated the magnitude and significance of sampling errors associated with radial gradients in SFD, which were based on the small monitoring measurement data from a few trees. Based on one year of heat pulse observation of two 3 - 4 years old Eucalyptus urophylla S. T.,P Blake plantations in Leizhou Peninsula, Guangdong Province, China, a way of data processing was developed to treat with the lots of SFD data measured from 39 trees. It was found that the radial variation in SFD as a function of sapwood thickness in the two eucalyptus plantation sites could be expressed as y = 3. 667 5x(3) - 7.295 5x(2) + 3.682 6x + 0. 567 4 (R-2 = 0. 939 1, n = 80, P = 0.01), where y is the ratio of SFD of a sensor to the average of four data in different depths, x is the ratio of a sensor depth to tire radial sapwood thickness. It was the same (as in the following equation) in Jijia site, y = 5.006 2x(3) - 9.116 1x(2) + 4. 454 4x + 0.463 4 (R-2 = 0. 806 9, n = 72, P = 0.01) in Hetou site. From cambium to heartwood, SFD showed some increases at first and then decreases continuously. However, because die trees were very young, the maximum SFD was only 0. 33 - 0. 36 times more than the minimum. 展开更多
关键词 radial variation sap flux density sapwood thickness eucalyptus trees
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Use of the pilodyn for assessing wood properties in standing trees of Eucalyptus clones 被引量:3
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作者 吴世军 徐建民 +4 位作者 李光友 RISTO Vuokko 陆钊华 李宝琦 王伟 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第1期68-72,I0003,共6页
The effectiveness of pilodyn was tested in evaluating wood basic density, outer wood density, heartwood density, and modulus of elasticity (MoE) at 22 four-year-old eucalyptus clones in Guangxi, China. Results indic... The effectiveness of pilodyn was tested in evaluating wood basic density, outer wood density, heartwood density, and modulus of elasticity (MoE) at 22 four-year-old eucalyptus clones in Guangxi, China. Results indicated that the mean value ranged from 9.44 to 15.41 mm for Pilodyn penetration, 0.3514 to 0.4913 g.cm^-3 for wood basic density, and 3.94 to 7.53 Giga Pascal (GPa) for MoE, respectively. There were significant differences (1% level) in pilodyn penetration between different treatments, different directions and among the clones. Generally strongly negative correlations were found between pilodyn penetration and wood properties, and the coefficients ranged from -0,433 to -0,755. Our results, together with other studies, suggest that the use of pilodyn for assessing wood density and MoE was confirmed as a possibility. 展开更多
关键词 CORRELATION eucalyptus modulus of elasticity PILODYN wood density
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A Study of the Distribution and Accumulation of Major Nutrient Elements in Different Densities of Eucalyptus grandis 被引量:5
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作者 王丽 龙汉利 +3 位作者 郭洪英 辜云杰 肖兴翠 盛玉珍 《Agricultural Science & Technology》 CAS 2017年第6期1062-1066,共5页
This study was conducted to investigate the distribution and accumulation of major elements of 5-year-old Eucalyptus grandis forests with the densities of 556 trees/hm2 and 1 667 trees/hm2. The results showed that: ... This study was conducted to investigate the distribution and accumulation of major elements of 5-year-old Eucalyptus grandis forests with the densities of 556 trees/hm2 and 1 667 trees/hm2. The results showed that: (1) The distribution of ma- jor nutrient element contents in various organs of the E. grandis with the 2 densi- ties was nearly the same, and the ranked order was leaf〉tree trunk〉branch or branchlet〉fruit〉bark. (2) From the distribution of nutrient elements and organic mat- ter in the trunk, P, K, Mg and Ca contents presented basically a trend of increasing with the trunk height increasing. And the organic matter content increased with the trunk height increasing in the low density stand, while the result was opposite in the high density stand. Furthermore, N content increased with the trunk height increas- ing in the low density stand, but the content in the high density stand exhibited a trend of decreasing at first, increasing then and increasing at the last. (3) From the distribution of biomass, the ranked order was tree trunk〉bark or branch〉branchlet〉 leaf〉fruit. And (4) The accumulated amounts of major nutrient elements in various organs under the 2 stand densities was nearly same. Ca content was the highest in the 2 kinds of plantations, followed by N, K, Mg and P contents. Ca content was 601.78 kg/hm2 in the low density stand and 1 204. 43 kg/hm2 in the high density stand. 展开更多
关键词 eucalyptus grandis Stand density Nutrient elements DISTRIBUTION
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基于Eucalyptus构建私有云计算平台 被引量:18
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作者 张帆 李磊 +1 位作者 杨成胡 陈丽珍 《电信科学》 北大核心 2011年第11期57-61,共5页
随着云计算的发展与深入,公有云在网站数据处理、在线服务等领域作用显著。与公有云相对,私有云计算凭借其安全性保障、高效个性化的弹性计算资源分配能力、简易的硬件要求等特性,逐渐在科研实验室、工作站、企业内部等小型分布式计算... 随着云计算的发展与深入,公有云在网站数据处理、在线服务等领域作用显著。与公有云相对,私有云计算凭借其安全性保障、高效个性化的弹性计算资源分配能力、简易的硬件要求等特性,逐渐在科研实验室、工作站、企业内部等小型分布式计算环境中得到广泛应用。本文基于Eucalyptus开源云计算平台,构建了一个适用于科研实验室及企业内部使用的私有云计算平台,既能弹性分配计算资源,满足开发、测试、管理等不同需求,又能为集群技术、分布式计算、云计算应用等研发工作提供实用平台。本文通过虚拟实例的仿真实验,验证了私有云计算平台在计算资源同构化时的优良性能。 展开更多
关键词 私有云 eucalyptus 弹性资源分配 同构化计算资源
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Eucalyptus开源框架下云平台的构建与性能分析 被引量:8
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作者 方薇 崔超远 王儒敬 《计算机系统应用》 2012年第6期1-5,共5页
基于Eucalyptus开源框架的云计算平台能够为用户提供硬件资源按需分配的服务。对云平台系统架构、网络及资源管理的解决方案进行了论述,并构筑了相应的云服务环境。通过对云环境下虚拟机实例与普通PC机在CPU、Memory、Disk I/O等性能的... 基于Eucalyptus开源框架的云计算平台能够为用户提供硬件资源按需分配的服务。对云平台系统架构、网络及资源管理的解决方案进行了论述,并构筑了相应的云服务环境。通过对云环境下虚拟机实例与普通PC机在CPU、Memory、Disk I/O等性能的比较,验证了所构建云计算平台的可用性和可扩展性。 展开更多
关键词 云计算平台 eucalyptus 虚拟机:性能测试 资源监控
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