It has been long believed there should be some relations between traffic system and urbanization,but the in-teraction between them,especially on the regional level,has been not in consideration due to the difficulty i...It has been long believed there should be some relations between traffic system and urbanization,but the in-teraction between them,especially on the regional level,has been not in consideration due to the difficulty in quantitative analysis.Based on the development of Jilin Province during 1981-2003,the paper analyzed the relation with the grey-relation model which was adjusted to fit specific problem,and came to some conclusions.Firstly,there exists ob-vious and strong correlation between traffic system and urbanization.Secondly,urbanization responds to the develop-ment of traffic system mainly on the level of urbanization,such as population and developed area,however,less on urbanization quality.Thirdly,traffic system influences urbanization as a whole except for several peculiar factors,which means we should optimize the whole traffic system to promote urbanization.Based on those conclusions,the paper illustrated the mechanism of traffic system,promoting urbanization scale and urbanization quality.展开更多
Clonal propagation of eucalypts has considerable importance due to the increasing demands for short rotation tree crops.Rooting quality is important as it governs the soil exploitation capacity of the plant and the an...Clonal propagation of eucalypts has considerable importance due to the increasing demands for short rotation tree crops.Rooting quality is important as it governs the soil exploitation capacity of the plant and the anchorage of trees which are susceptible to wind damage.This study assesses the quality of adventitious rooting by coppice cuttings of commercially important Eucalyptus clones using multiple attribute ranking of the diff erences in parameters of root growth.The eff ects of diff erent concentrations of indole-3-butyric acid(IBA)on root development were observed.Cuttings were treated with 500,1000,4000,6000 mg L−1 IBA and tannic acid for 10 s,2 h and 24 h.Total length of root systems,number of roots,shoot to root ratios,number of root segments,extent of forking,rooting percentage,average root diameters,and number of root tips were measured.Grey relational analysis was used to create a comparability sequence to rank treatments.Reducing the concentration of auxin(IBA)and increasing the length of exposure produced better quality roots in Eucalyptus camaldulensis and interspecifi c hybrids(reciprocal hybrids of E.tereticornis and E.camaldulensis),while the opposite was observed with E.tereticornis clones.A root quality index was proposed,based on the Dickson quality index for the assessment of root system characteristics and considered total mass,shoot:root ratios,total length of root systems,and average root diameters.It has the advantage of implementation convenience.A positive correlation was obtained between grey relational analysis grades and root quality index.Rooting dynamics were studied by evaluating the total length of the root system at seven-day intervals and plotting daily current and medium increments using regression analysis.The curves showed the variation in growth rates among the diff erent clones,and their intersection gave the optimal time of permanence(time at which further growth is restricted)which varied considerably.The highest daily current increment was 35–40 days for all clones.展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.40341008)
文摘It has been long believed there should be some relations between traffic system and urbanization,but the in-teraction between them,especially on the regional level,has been not in consideration due to the difficulty in quantitative analysis.Based on the development of Jilin Province during 1981-2003,the paper analyzed the relation with the grey-relation model which was adjusted to fit specific problem,and came to some conclusions.Firstly,there exists ob-vious and strong correlation between traffic system and urbanization.Secondly,urbanization responds to the develop-ment of traffic system mainly on the level of urbanization,such as population and developed area,however,less on urbanization quality.Thirdly,traffic system influences urbanization as a whole except for several peculiar factors,which means we should optimize the whole traffic system to promote urbanization.Based on those conclusions,the paper illustrated the mechanism of traffic system,promoting urbanization scale and urbanization quality.
文摘Clonal propagation of eucalypts has considerable importance due to the increasing demands for short rotation tree crops.Rooting quality is important as it governs the soil exploitation capacity of the plant and the anchorage of trees which are susceptible to wind damage.This study assesses the quality of adventitious rooting by coppice cuttings of commercially important Eucalyptus clones using multiple attribute ranking of the diff erences in parameters of root growth.The eff ects of diff erent concentrations of indole-3-butyric acid(IBA)on root development were observed.Cuttings were treated with 500,1000,4000,6000 mg L−1 IBA and tannic acid for 10 s,2 h and 24 h.Total length of root systems,number of roots,shoot to root ratios,number of root segments,extent of forking,rooting percentage,average root diameters,and number of root tips were measured.Grey relational analysis was used to create a comparability sequence to rank treatments.Reducing the concentration of auxin(IBA)and increasing the length of exposure produced better quality roots in Eucalyptus camaldulensis and interspecifi c hybrids(reciprocal hybrids of E.tereticornis and E.camaldulensis),while the opposite was observed with E.tereticornis clones.A root quality index was proposed,based on the Dickson quality index for the assessment of root system characteristics and considered total mass,shoot:root ratios,total length of root systems,and average root diameters.It has the advantage of implementation convenience.A positive correlation was obtained between grey relational analysis grades and root quality index.Rooting dynamics were studied by evaluating the total length of the root system at seven-day intervals and plotting daily current and medium increments using regression analysis.The curves showed the variation in growth rates among the diff erent clones,and their intersection gave the optimal time of permanence(time at which further growth is restricted)which varied considerably.The highest daily current increment was 35–40 days for all clones.