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Competitive polycondensation of model compound melamine-urea-formaldehyed(MUF)resin system by^(13)C NMR

Journal of Bioresources and Bioproducts 2020年第1期5卷 60-66页

作者： Jiankun Liang Quan Li Zhigang Wu Guanben Du Taohong Li Hong Lei Lifen Li Kaili university Qiandongnan 556011China College of forestry Guizhou UniversityGuiyang 550025China Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products Southwest Forestry UniversityKunming 650224China

Melamine-urea-formaldehyde(MUF)resin is an excellent adhesive in the field of wood adhe-sives,however the competition mechanism is questionable which affects the structure control and performance optimization of the *** this study,the competitive resin synthesis poly-condensation reaction of MUF system under alkaline condition was studied based on the model compound 1,3-dihydroxymethyl urea(UF_(2))and melamine(M)system,and the competitive reac-tion mechanism in the system was deduced by^(13)C NMR quantitative *** results show that the energy barrier of hydroxymethylation of melamine is lower than that of urea,and the priority of hydroxymethylation is lower;the addition of melamine results in a large amount of hy-drolysis of UF_(2),and the formed free formaldehyde,resulting in hydroxymethylation of melamine;there is obvious polycondensation reaction in UF_(2)+M system,mainly from the relationship be-tween hydroxymethylurea and melamine or *** type I bridge bond structure of polycondensation mainly comes from the reaction of UF_(2) and M,which is difficult to form the type II bridge *** low molar ratio,the formation of bridge bond is superior to that of ether *** the increase of molar ratio,the formation of ether bond shows advantages,but there is obvious competition between *** may be competitive presence of the UF self-condensation products,melamine-formaldehyde(MF)self-condensation products and MUF co-condensed products after the polycondensation reaction.

关键词： Model compound Melamine-urea-formaldehyde(MUF) Copolycondensation Competitiveness

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Application of CITYgreen5.0 model to tender appraisement of small-scale green-space designs

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forestry Studies in China 2008年第2期10卷 112-118页

作者： LIAO Wen-yan ZHAO Lin-sen Faculty of Landscape Architecture Southwest Forestry College Kunming 650224 R R. China

Developed by the American Forests, CITYgreen5.0 model has been widely applied to urban forestry research and has played an important role in analyzing quantitatively the ecological benefits produced by varied green-space ecosystems. One of the functions of this model is to evaluate quickly and objectively on parts of the ecological benefits possibly produced by different design schemes for the same small-scale green-space project before the establishment. A comparative analysis was conducted by modeling partial ecological benefits potentially produced by green-spaces of two different design schemes for the same roof garden of Chuangfushidai-Junjingyuan in Shenzhen, given the growth status of plants both immediately after the establishment and 20 years later. Meanwhile, the project costs for each design scheme were also taken into consideration. The results showed that scheme II, mainly designed with a natural style of plant disposition, had a better greenery structure than that of scheme I, which was basically designed with a regular style of plant disposition. The estimated value of the partial ecological benefits produced by scheme II was larger than that of scheme I and the benefit-cost ratio of scheme II was more rational. It was suggested that scheme II be put into practice.

关键词： CITY green 5.0 garden design ecological benefit evaluation plant disposition

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Diversity of wood-decaying fungi in Haikou forestry Farm,Yunnan Province,***

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Studies in Fungi 2021年第1期6卷 365-377页

作者： He X Chen JZ Zhao CL College of Biodiversity Conservation Southwest Forestry UniversityKunming 650224P.R.China

Nine field trips carried out in Haikou forestry Farm,Yunnan Province,*** resulted in 681 specimens of wood-decaying *** present paper summarizes 52 species collected that are distributed in 37 genera,16 families,6 orders including their hosts and substrates.A checklist of wood-decaying fungi in Haikou forestry Farm is also *** analysis of ITS nrRNA gene region was performed for all the collected samples with maximum likelihood,maximum parsimony and Bayesian inference *** phylogenetic tree showed that fifty-two species nested in sixteen families belonging to six orders in Agaricomycetes.

关键词： Basidiomycota biological resources diversity Haikou forestry Farm mycota

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Complex interplay between formation routes and natural organic matter modification controls capabilities of C_(60)nanoparticles(nC_(60)) to accumulate organic contaminants

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Journal of Environmental Sciences 2017年第1期29卷 315-323页

作者： Lei Hou John D.Fortner Ximeng Wang Chengdong Zhang Lilin Wang Wei Chen College of Environmental Science and Engineering Southwest Forestry University College of Environmental Science and Engineering Nankai University Department of Energy Environmental and Chemical EngineeringWashington University in St.Louis

Accumulation of organic contaminants on fullerene nanoparticles（nC（60）） may significantly affect the risks of C（60） in the *** objective of this study was to further understand how the interplay of nC（60） formation routes and humic acid modification affects contaminant adsorption of nC（60）.Specifically,adsorption of 1,2,4,5-tetrachlorobenzene（a model nonionic,hydrophobic organic contaminant） on nC（60） was greatly affected by nC（60）formation route- the formation route significantly affected the aggregation properties of nC（60）,thus affecting the available surface area and the extent of adsorption via the pore-filling *** on whether nC（60） was formed via the ＂top-down＂ route（i.e.,sonicating C（60） powder in aqueous solution） or ＂bottom-up＂ route（i.e.,phase transfer from an organic solvent） and the type of solvent involved（toluene versus tetrahydrofuran）,modification of nC（60） with Suwannee River humic acid（SRHA） could either enhance or inhibit the adsorption affinity of nC（60）.The net effect depended on the specific way in which SRHA interacted with C（60） monomers and/or C（60） aggregates of different sizes and morphology,which determined the relative importance of enhanced adsorption from SRHA modification via preventing C（60） aggregation and inhibited adsorption through blocking available adsorption *** findings further demonstrate the complex mechanisms controlling interactions between nC（60） and organic contaminants,and may have significant implications for the life-cycle analysis and risk assessment of C（60）.

关键词： Fullerene nanoparticles Aggregation Natural organic matter Organic contaminants Adsorption

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Urban land-use impacts on composition and spatiotemporal variations in abundance and biomass of earthworm community

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Journal of forestry Research 2020年第1期31卷 325-331页

作者： Jihang Li Zhe Zhang Hong Wang Shaojun Wang Qibo Chen College of Ecology and Soil&Water Conservation Southwest Forestry UniversityBailongsi 300Kunming 650224People’s Republic of China Co-Innovation Center for Sustainable forestry in Southern China College of Biology and the EnvironmentNanjing Forestry UniversityLongpan Road 159Nanjing 210037People’s Republic of China

Soil fauna can sensitively respond to alterations in soil environment induced by land-use ***,little is known about the impact of urban land-use changes on earthworm *** this study,three land-use types(i.e.,forest,nursery and abandoned lands)were chosen to identify differences in diversity,abundance and biomass of earthworm community in Kunming *** land-use had a pronounced difference in species composition,evenness and diversity of earthworm *** land had the highest density,biomass and diversity of the earthworm *** abundance was dominated by endogeic species in nursery land(70%)and abandoned land(80%),whereas in the forest land,the earthworm community comprised epigeic,endogeic and anecic *** changes in earthworm density and biomass were also significantly affected by land-use *** density and biomass of earthworms in the forest and nursery lands were highest in September,but highest in the abandoned land in *** influence of soil physicochemical properties on the earthworm density and biomass also varied with land-use *** temperature significantly affected earthworm density and biomass in the three land-use *** pH was positively correlated with earthworm biomass in the forest land,but negatively associated with earthworm density in the abandoned *** organic matter was positively correlated only with density and biomass of earthworms in the nursery and abandoned *** results suggest that the species composition,abundance and biomass of earthworm communities can be determined by the modification of soil properties associated with urban land-use type.

关键词： Biomass Density Earthworm community Soil physicochemical properties Spatiotemporal dynamics

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The Poetics of Process Repeated in the Sky

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Journal of Foreign Languages and Cultures 2018年第1期2卷 141-154页

作者： Zewei Jiang southwest forestry university

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Application of Blank Symbols in Japanese Architecture and Indoor Designs

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Contemporary Social Sciences 2023年第3期8卷 145-155页

作者： Zhang Zhanzhi Wu Pengjun Zheng Shaojiang southwest forestry university

A symbol is an expression of meaning,while blank symbols express special *** focusing on the application of blank symbols in Japanese architecture and indoor designs,we analyzed the aesthetic principles in Japanese architecture and indoor designs from the perspective of semiotics,such as“Kongji,”“Emptiness,”and“Dying out,”and their minimalist and pure design *** Chinese culture was also further explored,especially the profound influence of the“Chan sect”and the philosophy of“unity of heaven and mankind”on Japanese architecture and *** study aims to facilitate the coexistence and mutual appreciation of Chinese and Japanese architectural designs.

关键词： Blank symbols Japanese culture architectural designs indoor designs traditional Chinese aesthetics

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Distribution patterns and changes of aquatic plant communities in Napahai Wetland in northwestern Yunnan Plateau,China

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Frontiers in Biology 2008年第3期3卷 338-343页

作者： Derong XIAO Kun TIAN Hua YUAN Yuming YANG Ningyun LI Shouguo XU State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200062China Department of Environment Science and Engineering Southwest Forestry CollegeKunming 650224China State forestry Administration Key Laboratory for Biodiversity Conservation in southwest China Kunming 650224China

Using GPS technology and community research methods for plant communities,we investigated the distribution patterns of aquatic plant communities in the high plateaus of the Napahai Wetlands,Yunnan,China,as well as the species changes of plant communities compared with that of 24 years ago since *** found that the types and numbers of aquatic plant communities have *** pollution-tolerant,nutrient-loving plant communities such as Scirpus tabernaemontani,Zizania caduciflora,Myriophyllum spicatum,and Azolla imbricata flourished,while the primary aquatic plant communities were reduced or even *** number of aquatic plant communities were increased from nine to 12 with the addition of two new emergent plant communities and one new floating-leaved plant *** increase in emergent plant communities was *** east to west and from south to north,various types of plant communities were continuously distributed,including floating-leaved plant communities,emergent plant communities and submerged plant *** composition of the communities became more complicated and the number of accompanying species increased,while the percentage ratio of dominant plant species *** 2005,the coverage of emergent plant communities was the largest(528.42 hm^(2))followed by submerged plant communities(362.50 hm^(2))and the floating-leaf plant communities was the smallest(70.23 hm^(2)).The variations in the distribution of aquatic plant communities in the Napahai Wetlands reflect the natural responses to the change of the wetland ecological *** study indicates that human disturbances have led to an inward movement of the wetland shoreline,a decrease in water quality and a reduction in wetland habitat.

关键词： plateau wetland plant community distribution pattern change trends Napahai

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Evaluation method of the ecological benefits of urban green spaces and application conditions

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forestry Studies in China 2007年第3期9卷 213-216页

作者： Wang Wei Zhao Lin-sen Faculty of Landscape Architecture Southwest Forestry College Kunming 650224 E R. China

The importance of ecological benefit analyses about green space systems has been widely discussed on the basis of a perceived bias towards the landscaping effect of green spaces to be built in urban areas as opposed to the perception of comprehensive ecological benefits of designed plant communities. Given the basic principle of ecological benefit analyses and evaluation methods widely applied today, the methodology to calculate ecological benefits and to model the expansion of urban green spaces by CITY- green 5.0 and its conditions for application were explored. We propose that aerial images can be substituted by AutoCAD graphics of a green space containing detailed information of plant dispositions by digitizing the key features during the working process in order to evaluate the ecological benefits quickly and to offer proper guidance to the establishment of small scale green spaces in urban areas. The theoretical foundation, potential application range and prospects for extension of the method are introduced by using the analysis of ecological benefits of the green spaces on the campus of southwest forestry College, Kunming, as an example.

关键词： urban green spaces ecological benefits evaluation CITYgreen 5.0 ArcView GIS

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Three New Xanthones from Polygala crotalarioides

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Chinese Chemical Letters 2006年第6期17卷 773-775页

作者： Yan HUA Chang Xiang CHEN Yu Qing LIU Shu Kun CHEN Jun ZHOU State Key Laboratory of Phytochemistry and Plant Resource in West China Kunmin~ Institute of Botany Academia Sinica Kunming 650204 southwest forestry College Kunming 650224

Three new xanthones, 3, 6-dihydroxy-1, 2, 7-trimethoxyxanthone 1, 1, 3, 6-trihydroxy-2, 7, 8-trimethoxyxanthone 2, and 3, 6-dihydroxy-1, 2, 7, 8-tetramethoxyxanthone 3, were isolated from the roots of Polygala crotala... 详细信息

关键词： Polygala crotalarioides chemical constituents xanthones.

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