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Journal of Renewable Materials 2021年第12期9卷 2209-2222页

作者： Shuang Si Qian Tang xingong li Central South University of Forestry and Technology Changsha410004China

This study investigated the characteristics of wood fiber/polycaprolactone composite after an artificial accelerated thermo-oxidative aging *** effect of time,temperature and humidity during the treatment on their mechanical,chemical and morphology properties were *** composite was prepared from melted wood fibers and modified polycaprolactone by a molding process.A temperature and humidity controllable test chamber was used for the thermo-oxidative aging of the *** thermo-oxidative aging caused surface of the composite to be much more rougher and even a few cracks and holes appeared on *** to the spectra of Fourier Transform Infrared(FTIR)and Gel Permeation Chromatography(GPC),C=O in the molecular chain of polycaprolactone was hydrolyzed and C–O was broken after the aging treatment,which resulted in a reduction in average molecular weight of the ***,results showed that the mechanical strength decreased a lot with the increase in time,temperature and humidity,and the effect of temperature and humidity was more significant compared with that of *** the temperature and humidity during thermo-oxidative aging treatment could accelerate the aging of composite,which provided a quick and effective method for evaluating the aging resistance of the composite.

关键词： Wood fiber polycaprolactone wood plastic composite thermo-oxidative aging

Selecting the Technology of Sodium Silicate Modified Poplar with the Highest Performance by Fuzzy Orthogonal Method

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Journal of Renewable Materials 2023年第5期11卷 2399-2415页

作者： Xiaoqian Bi Pengfei Guan Ping li Yuan Zhang xingong li Yingfeng Zuo College of Materials Science and Engineering Central South University of Forestry and TechnologyChangsha410004China College of Furniture and Art Design Central South University of Forestry and TechnologyChangsha410004China

Sodium silicate modification can improve the overall performance of *** modification process has a great influence on the properties of modified *** this study,a new method was introduced to analyze the wood modification process,and the properties of modified wood were *** wood was modified with sodium silicate by vacuum-pressure *** screening using single-factor experiments,an orthogonal experiment was carried out with solution concentration,impregnation time,impregnation pressure,and the cycle times as experimental *** modified poplar with the best properties was selected by fuzzy mathematics and characterized by SEM,FT-IR,XRD and *** results showed that some lignin and hemicellulose were removed from the wood due to the alkaline action of sodium silicate,and the orderly crystal area of poplar became disorderly,resulting in the reduction of crystallinity of the modified poplar ***-IR analysis showed that sodium silicate was hydrolyzed to form polysilicic acid in wood,and structural analysis revealed the formation of Si-O-Si and Si-O-C,indicating that sodium silicate reacted with fibers on the wood cell ***-DTG curves showed that the final residual mass of modified poplar wood increased from 25%to 67%,and the temperature of the maximum loss rate decreased from 343℃ to 276℃.The heat release and smoke release of modified poplar wood decreased *** kind of material with high strength and fire resistance can be used in the outdoor building and indoor furniture.

关键词： Poplar wood sodium silicate impregnation modification fuzzy orthogonal method process optimization flame retardant

Comparative Study on the Properties of Inorganic Silicate and Organic Phenolic Prepolymer Modified Poplar Wood by Vacuum Cycle Pressurization

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Journal of Renewable Materials 2022年第9期10卷 2451-2463页

作者： Pengfei Guan Ping li Yiqiang Wu xingong li Guangming Yuan Yingfeng Zuo College of Materials Science and Engineering Central South University of Forestry and TechnologyChangsha410004China College of Furniture and Art Design Central South University of Forestry and TechnologyChangsha410004China

To enhance mechanical properties and improve flame retardancy and smoke suppression of fast-growing poplar wood in wood applications,the wood was impregnated and *** organic phenolic prepolymer and inorganic sodium silicate was used as contrasting impregnation modifiers and wood samples were impregnated by a bionic“respiration”method with alternating positive and negative *** weight percentage gain,density increase ratio,mechanical properties(bending and compressive strength and hardness),and water absorption rate of inorganic and organic-impregnated modified poplar wood(IIMPW and OIMPW,respectively)were compared and these properties in IIMPW were found to be higher than those of OIMPW with the exception of the water absorption rate which was lower than the *** was attributed to the superior absorption of sodium silicate that also improved the impregnation,reinforcement,and dimensional stability in the *** chemical structure,crystalline structure,internal morphology,flame retardancy,smoke suppression,and thermal stability of IIMPW and OIMPW were characterized by FT-IR,XRD,SEM,CONE,and ***-IR and XRD results showed that,although IIMPW cellulose crystallinity reduced the most,more chemical bonds were come into being in IIMPW,which explained the better physical and mechanical properties of *** with OIMPW,IIMPW had better flame retardant and smoke suppression performance.

关键词： Poplar wood sodium silicate impregnation modification mechanical properties dimensional stability flame retardancy and smoke suppression

Impacts of temperature and precipitation on runoff in the Tarim River during the past 50 years

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Journal of Arid Land 2011年第3期3卷 220-230页

作者： YuTing FAN YaNing CHEN WeiHong li HuaiJun WANG xingong li State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Department of Geography University of Kansas Lawrence KS 66045 USA

The relationship between climate change and water resources in the Tarim River was analyzed by combining the temperature,precipitation and streamflow data from 1957 to 2007 from the four headstreams of the Tarim River （Aksu,Hotan,Yarkant and Kaidu rivers） in the study *** long-term trend of the hydrological time series including temperature,precipitation and streamflow were studied using correlation analysis and partial correlations *** double exponential smoothing was used to fit the trends between streamflow and the two climatic factors of Aksu River,Hotan River and Yarkant *** streamflow of the main stream was forecasted by Autoregressive Integrated Moving Average Model （ARIMA） modeling by the method of time series *** results show that the temperature experienced a trend of monotonic *** precipitation and runoff of the four headstreams of the Tarim River increased,while the inflow to the headstreams increased and the inflow into the Tarim River *** of temperature and precipitation had a significant impact on runoff into the four headstreams of the Tarim River： the precipitation had a positive impact on water flow in the Aksu River,Hotan River and Kaidu River,while the temperature had a positive impact on water flow in the Yarkant *** results of Holt double exponential smoothing showed that the correlation between the independent variable and dependent variable was relatively close after the model was fitted to the headstreams,of which only the runoff and temperature values of Hotan River showed a significant negative *** forecasts by the ARIMA model for 50 years of annual runoff at the Allar station followed the pattern of the measured data for the same *** short-term forecasts beyond the observed series adequately captured the pattern in the data and showed a decreasing tendency in the Tarim River flow of 3.07% every ten *** results showed that global warming accelerated the water

关键词： Tarim River Basin climate change hydrological change water resources streamflow

Evaluation of oasis stability in the lower reaches of the Tarim River

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Journal of Arid Land 2011年第2期3卷 123-131页

作者： Chao LENG YaNing CHEN xingong li YanXia SUN Key Laboratory of Oasis Ecology and Desert Environment Xinjiang Institute of Ecology and Geography Chinese Academy ofSciences Urumqi 830011 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Department of Geography University of Kansas Lawrence KS 66045 USA

Oasis stability in the lower reaches of the Tarim River was assessed at the landscape scale（including changes in landscape pattern and land use in the oasis） and at the regional scale（including the cold-island effect and NDVI of the oasis） based on the methods of landscape ecology,GIS and Remote Sensing（RS）.Thematic Mapping（TM） remote sensing images from 1990,2000 and 2009 were employed along with the related meteorological and hydrological data pertaining to the reclamation area of the oasis in the lower reaches of the Tarim *** results indicated that landscape heterogeneity and oasis complexity increased between 1990 and *** comprehensive index of the degree of land use,the average index of the cold-island effect,NDVI value and oasis stability all ***,the change trends in the indices referred to above were opposite between 2000 and 2009,and oasis stability was enhanced to some extent.

关键词： oasis stability landscape scale regional scale the lower reaches of the Tarim River

Optical and Mechanical Properties of Ramie Fiber/Epoxy Resin Transparent Composites

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Journal of Renewable Materials 2023年第10期11卷 3613-3624页

作者： Chunhua liu Dongfang Zou Qinqin Huang Shang li Xia Zheng xingong li College of Materials Science and Engineering Central South University of Forestry and TechnologyChangsha410004China College of Foreign Languages Central South University of Forestry and TechnologyChangsha410004China

The residual resources of ramie fiber-based textile products were used as raw *** fiber felt(RF)was modified by NaClO_(2) aqueous solution and then impregnated with water-based epoxy resin(WER).RF/WER transparent composite materials were prepared by lamination hot pressing *** composite materials’color difference,transmittance,haze,density,water absorption,and mechanical properties were determined to assess the effects of NaClO_(2) treatment and the number of ramie fiber layers on the properties of the prepared *** results showed significantly improved optical and mechanical properties of the RF/WER transparent composites after NaClO_(2) *** the increase of ramie fiber layers,the composites’whiteness,transmittance,and water absorption decreased while the haze *** material with three layers,the optical transmittance in the visible light region was 82%,and the haze was 96%,indicating the material has both high transmittance and high haze *** tensile strength increases with the increase of the number of layers,and the tensile strength of the composite with six layers is 243 *** study broadens the scope of application of ramie fiber as a new option for home decoration materials.

关键词： Ramie fiber water-based epoxy transparent composites transmittance haze tensile strength

Waste to wealth: Oxygen-nitrogen-sulfur codoped lignin-derived carbon microspheres from hazardous black liquors for high-performance DSSCs

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Journal of Energy Chemistry 2023年第8期83卷 549-563,I0013页

作者： Wenjie Cheng Caichao Wan xingong li Huayun Chai Zhenxu Yang Song Wei Jiahui Su Xueer Tang Yiqiang Wu College of Materials Science and Engineering Central South University of Forestry and TechnologyChangsha 410004HunanChina School of Biomedical Engineering The University of SydneySydneyNew South Wales 2006Australia The University of Sydney Nano Institute The University of SydneySydneyNew South Wales 2006Australia

Carbon materials are effective substitutes for Pt counter electrodes(CEs) in dye-sensitized solar cells(DSSCs). However, many of these materials, such as carbon nanotubes and graphene, are expensive and require complex preparation process. Herein, waste lignin, recycled from hazardous black liquors,is used to create oxygen-nitrogen-sulfur codoped carbon microspheres for use in DSSC CEs through the facile process of low-temperature preoxidation and high-temperature self-activation. The large number of ester bonds formed by preoxidation increase the degree of cross-linking of the lignin chains, leading to the formation of highly disordered carbon with ample defect sites during pyrolysis. The presence of organic O/N/S components in the waste lignin results in high O/N/S doping of the pyrolysed carbon,which increases the electrolyte ion adsorption and accelerates the electron transfer at the CE/electrolyte interface, as confirmed by density functional theory(DFT) calculations. The presence of inorganic impurities enables the construction of a hierarchical micropore-rich carbon structure through the etching effect during self-activation, which can provide abundant catalytically active sites for the reversible adsorption/desorption of electrolyte ions. Under these synergistic effects, the DSSCs that use this novel carbon CE achieve a quite high power-conversion efficiency of 9.22%. To the best of our knowledge, the value is a new record reported so far for biomass-carbon-based DSSCs.

关键词： lignin Carbon microspheres Codoping Hierarchical pores DSSCs

Global Economic Imbalance and China's OPtion

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China International Studies 2008年第1期28卷 103-118页

作者： li xingong Professor at Institute of Business Administration Henan University

The world economic imbalance is mainly attributable to the huge current account deficits of the United *** imbalance is not a new *** the 1980s,the continuous worsening of the *** account deficit triggered the

关键词：全球经济平衡中国经济选择经济决策

Spatial and temporal trends of climate change in Xinjiang, China

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Journal of Geographical Sciences 2011年第6期21卷 1007-1018页

作者： li Qihu CHEN Yaning SHEN Yanjun li xingong XU Jianhua Key Lab of GIScience of the Ministry of Education East China Normal University Shanghai 200062 China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography CAS Urumqi 830002 China Key Laboratory of Agricultural Water Resources Center for Agricultural Resources Research CAS Shijiazhuang 050021 China Department of Geography University of Kansas Lawrence KS 66045 USA

Temperature and precipitation time series datasets from 1961 to 2005 at 65 meteorological stations were used to reveal the spatial and temporal trends of climate change in Xinjiang, China. Annual and seasonal mean air temperature and total precipitation were analyzed using Mann-Kendall （MK） test, inverse distance weighted （IDW） interpolation, and R/S methods. The results indicate that：（1） both temperature and precipitation increased in the past 45 years, but the increase in temperature is more obvious than that of precipitation; （2） for temperature increase, the higher the latitude and the higher the elevation the faster the increase, though the latitude has greater influence on the increase. Northern Xinjiang shows a faster warming than southern Xinjiang, especially in summer; （3） increase of precipitation occurs mainly in winter in northern Xinjiang and in summer in southern Xinjiang. lli, which has the most precipitation in Xinjiang, shows a weak increase of precipitation; （4） although both temperature and precipitation increased in general, the increase is different inside Xinjiang; （5） Hurst index （H） analysis indicates that climate change will continue the current trends.

关键词： climate change MK test Xinjiang IDW R/S

冻-融循环老化对竹纤维/聚丙烯复合材料性能的影响

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复合材料学报 2024年第11期41卷 6148-6155页

作者：李振宇李新功中南林业科技大学材料科学与工程学院长沙410004

竹纤维/聚丙烯(BF/PP)复合材料常应用于户外市政工程领域。在高纬度地区时冷热湿冻的交变作用会使材料性能严重劣化。为探究BF/PP复合材料在高纬度地区的耐老化性能,采用相容剂和偶联剂协同改性的方法制备了BF/PP复合材料,研究了该材料... 详细信息

竹纤维/聚丙烯(BF/PP)复合材料常应用于户外市政工程领域。在高纬度地区时冷热湿冻的交变作用会使材料性能严重劣化。为探究BF/PP复合材料在高纬度地区的耐老化性能,采用相容剂和偶联剂协同改性的方法制备了BF/PP复合材料,研究了该材料在冻-融循环老化处理后的物理力学性能及表观性能的变化规律。采用5400 s短期蠕变试验方法研究了材料的蠕变行为,并采用扫描电子显微镜和傅里叶红外光谱分析了材料的微观形貌与化学组成。结果显示:720 h冻-融循环老化后,BF/PP复合材料的抗拉强度、抗弯强度、弯曲弹性模量、无缺口冲击强度的保留率分别为76.90%、86.89%、82.81%、71.83%;材料产生了较深的交叉裂纹、孔洞和断层,表面疏水性下降,并出现了明显的色泽改变。进一步采用Burgers模型对BF/PP复合材料的5400 s短期蠕变行为进行了拟合,探明了冻-融循环老化对BF/PP复合材料抗蠕变性能的影响机制。

关键词：生物质复合材料竹纤维老化冻融循环聚丙烯力学性能