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EFFECT OF NANOCRYSTALLINE CELLULOSE ON THE CURING CHARACTERISTICS AND AGING RESISTANCE PROPERTIES OF CARBON BLACK REINFORCED NATURAL RUBBER

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Chinese Journal of Polymer Science 2013年第10期31卷 1382-1393页

作者： ju Gu Wan-juan Chen Lu Lin Yuan-fang Luo De-min Jia College of Materials Science and Engineering South China University of Technology

This work focused on the effect of nanocrystalline cellulose （NCC） on the curing characteristics, aging resistance and thermal stability of natural rubber （NR） reinforced with carbon black （CB）. Sharing the same fillers loading of 45 parts per hundred rubber （phr）, NR/NCC/CB composites with different NCC/CB ratios （i.e. 0/45, 5/40, 10/35, 15/30, 20/25 phr） were prepared and analyzed. Resorcinol and hexamethylene tetramine （RH）, acting as the modifier in NR/NCC interface, was also discussed for its influence. The result showed that an relatively higher ratio of NCC/CB led to a lower torque, a shorter cure time （Tg0）, a slightly longer scorch time （Ti0） and a bigger vulcanization rate constant （K）. This tendency suggested that the existence of NCC accelerated the vulcanization process. Additionally, modified by RH, NR/NCC/CB compounds exhibited a short T10 and a elevated torque. And a moderate RH content would lower the E of vulcanization. A 10 phr substitute of CB by NCC can help to improve aging resistance in terms of mechanical properties. In a high temperature aging condition, composites with 10 phr NCC also performed the highest storage modulus （G＇） among composites tested. A moderate NCC content contributed to the best retention of G＇ after high temperature aging, so did the incorporation of RH. With the partial replacement of CB by NCC, the temperature of 5% weight-lose had a slight drop and the apparent crosslink density showed a decrease. Thanks to the interaction of RH with both NR and NCC, composites showed an improvement in apparent crosslink density after modified by RH.

关键词： Nanocrystalline cellulose Natural rubber Curing characteristics Aging resistance Thermal stability.

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Dispersion of ultrafine SiC particles in molten Al-12Si alloy

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Transactions of Nonferrous Metals Society of China 2011年第A01期21卷 33-36页

作者： Jin-ju PARK Sang-Hoon LEE min-Ku LEE Chang-Kyu RHEE Nuclear Materials Research Division Korea Atomic Energy Research Institute Daejeon 305-353 Korea

The bulk A1-12 Si eutectic composites were fabricated through a conventional liquid metal casting route, especially with the help of ultrafine ceramic powders made by self-propagating high-temperature synthesis （SHS） process. The SHS powders were fabricated by the chemical reaction between micro-sized SiC and A1 particles at very high combustion temperatures, producing the coarse A1 particles （several tens of microns） containing ultrafine SiC ceramic particles. Microstructural observation revealed that the addition of ultrafine SiC particles has a crumbling tendency of Si eutectic phase. It is suggested that the casting method combined with SHS process is promising for fabricating the Al-based MMC with ultrafine ceramic particles.

关键词： AI-12Si alloy dispersion self-propagating high-temperature synthesis (SHS) ultrafine ceramic SiC

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Ablative Property of C/C–SiC–HfC Composites Prepared via Precursor Infiltration and Pyrolysis under 3,000 °C Oxyacetylene Torch

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Acta Metallurgica Sinica(English Letters) 2014年第6期27卷 981-987页

作者： min Yan Hejun Li Qiangang Fu Jing xie Lei Liu Bo Feng C/C Composites Technology Research Center State Key Laboratory of Solidification Processing Northwestern Polytechnical University

C/C–SiC–HfC composites were fabricated via precursor infiltration and pyrolysis using a mixture solution of organic hafnium-containing polymer and polycarbosilane as precursor. The microstructures and the phases of the composites were analyzed by scanning electron microscopy and X-ray diffraction. The ablation resistance of the composites was evaluated under 3,000 °C oxyacetylene torch. After ablation for 120 s, the composites exhibit good ablation properties with the linear and mass ablation rates of 9.1 9 10-4mm/s and 1.30 9 10-3g/s, which are far lower than those of the C/C–SiC composites. The excellent ablative property of the C/C–SiC–HfC composites is resulted from the formation of HfO2 molten layer on the surface of the composites, which could play a positive role in reducing heat transfer and preventing oxygen transport to the underlying carbon substrate.

关键词： C/C–SiC–HfC composite Ablation performance Thermal behavior

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Tailoring color emissions from N-doped graphene quantum dots for bioimaging applications

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Light(Science & Applications) 2015年第1期4卷 8-15页

作者： Dan Qu min Zheng Jing Li Zhigang xie Zaicheng Sun State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesNo.3888 Dong Nanhu RoadChangchun 130033China University of Chinese Academy of Sciences No.19AYuquan RoadBeijing 100049China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesNo.5625Renmin StreetChangchun 130022China Beijing Key Laboratory for Green Catalysis and Separation Department of Chemistry and Chemical EngineeringBeijing University of Technology100 PingleyuanChaoyang DistrictBeijing 100124China

Unlike inorganic quantum dots,fluorescent graphene quantum dots(GQDs)display excitation-dependent multiple color *** this study,we report N-doped GQDs(N-GQDs)with tailored single color emission by tuning p-conjugation degree,which is comparable to the inorganic quantum *** from citric acid and diethylenetriamine,as prepared N-GQDs display blue,green,and yellow light emission by changing the reaction solvent from water,dimethylformamide(DMF),and solvent *** X-ray photoelectron spectroscopy,ultraviolet-visible spectra results clearly show the N-GQDs with blue emission(N-GQDs-B)have relatively short effective conjugation length and more carboxyl group because H_(2)O is a polar protic solvent,which tends to donate proton to the reagent to depress the H_(2)O elimination *** the other hand,the polar aprotic solvent(DMF)cannot donate hydrogen,the elimination of H_(2)O is promoted and more nitrogen units enter GQD *** the increase of effective p-conjugation length and N content,the emission band of N-GQDS red-shifts to green and *** also demonstrate that N-GQDs could be a potential great biomarker for fluorescent bioimaging.

关键词： excitation wavelength independent graphene quantum dots nitrogen doped pure color emission

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A Novel Two-Layer Model for Overall Quality Assessment of Multichannel Audio

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China Communications 2017年第9期14卷 42-51页

作者： Jiyue Liu Jing Wang min Liu Xiang xie Jingming Kuang School of Information and Technology Beijing Institute of Technology

With the development of multichannel audio systems, corresponding audio quality assessment techniques, especially the objective prediction models, have received increasing attention. Existing methods, such as PEAQ(Perceptual Evaluation of Audio Quality) recommended by ITU, usually lead to poor results when assessing multichannel audio, which have little correlation with subjective scores. In this paper, a novel two-layer model based on Multiple Linear Regression(MLR) and Neural Network(NN) is proposed. Through the first layer, two indicators of multichannel audio, Audio Quality Score(AQS) and Spatial Perception Score(SPS) are derived, and through the second layer the overall score is output. The final results show that this model can not only improve the correlation with the subjective test score by 30.7% and decrease the Root Mean Square Error(RMSE) by 44.6%, but also add two new indicators: AQS and SPS, which can help reflect the multichannel audio quality more clearly.

关键词： multichannel audio two-layermodel audio quality assessment multiple lin-ear regression neural network

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The selectivity of triethylene glycol modified glassy carbon electrode for charged and uncharged pieces

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Chinese Chemical Letters 2015年第11期26卷 1421-1425页

作者： ju-Jie Ren Na Sun min Cui Xue-Ping Ji Department of Chemistry School of Sciences Hebei University of Science and Technology Department of Medical Chemistry Hebei Medical University

A triethylene glycol modified glassy carbon electrode （TEG-GCE） was fabricated by a controlled- potential electrolysis procedure. The performance of the film on the modified electrode surface was investigated by cyclic voltammetry with different probes. It was firstly found that while neutral pieces could penetrate the TEG film on the GCE surface, the ionic pieces, whatever it is anion or cation, was blocked by the film. This property was successfully used for determining dopamine （DA） in the presence of ascorbic acid （AA） with differential pulse voltammetry （DPV）.

关键词： Triethylene glycolGlassy carbon electrodeDopamineAscorbic acidElectrochemical modification

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Study on the element geochemical charactersitics of the Shazi large-sized anatase ore deposit in Qinglong, Guizhou Province

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Chinese Journal Of Geochemistry 2014年第3期33卷 316-323页

作者： ZHANG min NIE Aiguo xie Fei ZHU mingjin ZHANG Zhuru Guizhou University Guizhou Coal mine Design and Research Institute Guizhou Institute of Technology

The Shazi anatase ore deposit in Qinglong, Guizhou Province, is a large-sized anatase deposit that has been recently explored. The characteristics of major oxides in the ore are similar to those of modern laterite weathering crust and laterite in the laterite-type gold deposits in the western part of Guizhou Province. Studies on the REE characteristics of basalts and anatase ores in the study region showed that both of them do have extremely strong affinities. There are two groups of trace elements in the ores, i.e., Au-Ag-As-Sb-Hg-Tl association and Sc-TiO2-Cu-Fe-Mn association, reflecting that the formation of anatase ore is related to the formation of siliceous claystone at the early stage of eruption of the Emeishan basaltic magma. The siliceous claystones are the major country rocks for the formation of laterite-type gold ores and anatase ores. In the region anatase ores are rich in Sc and the basalts enriched in Fe, Mn, Ti and Sc are the material source of metallogenesis.

关键词：地球化学特性稀土元素锐钛矿贵州省矿床峨眉山玄武岩红土型金矿作者

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Photocatalytic remediation ofγ-hexachlorocyclohexane contaminated soils using TiO_2 and montmorillonite composite photocatalyst

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Journal of Environmental Sciences 2007年第3期19卷 358-361页

作者： ZHAO Xu QUAN xie CHEN Shuo ZHAO Hui-min LIU Yu Department of Environmental Science and Technology Dalian University of Technology Dalian 116024 China State key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China.

TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane （γ-HCH） in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocatalysts were exposed to UV-light irradiation. The results indicated that the photocatalytic activities of the composite photocatalysts varied with the content of TiO2 in the order of 10%〈70%〈50% 〈30%, Moreover, the photocatalytic activity of the composite photocatalysts with TiO2 content 30% was higher than that of the pure P25 with the same mass of TiO2. The strong adsorption capacity of the composite photocatalysts and quantum size effect may contribute to its increased photocatalytic activities. In addition, effect of dosage of composite photocatalysts and soil pH on γ-HCH photodegradation was investigated. Pentachlorocyclohexene, trichlorocyclohexene, and dichlorobenzene were detected as photodegradation intermediates, which were gradually degraded with the photodegradation evolution.

关键词： TiO2 montmorillonite γ-HCH soil surfaces composite photocatalysts

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Isolation,expression and single nucleotide polymorphisms(SNPs) analysis of LACCASE gene(LkLAC8) from Japanese larch(Larix kaempferi)

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Journal of Forestry Research 2017年第5期28卷 891-902页

作者： Changyong Liu Yunhui xie min Yi Shougong Zhang Xiaomei Sun State Key Laboratory of Tree Genetics and Breeding Research Institute of ForestryChinese Academy of Forestry Research Institute of Forestry Chinese Academy of Forestry State Academy of Forestry Administration School of Gardening and Landscape Design Jiangxi Agricultural University

Nucleotide diversity (pi) and linkage disequilibrium (LD) analysis based on SNP marker could provide a sound basis for choosing an association analysis method. Japanese larch (Larix kaempferi) is an important timber coniferous tree species for pulping and papermaking, but its high lignin content has significantly restricted it application potential. In this study, the LACCASE gene, that plays an important regulatory role for lignin biosynthesis, was selected as research target. The full-length cDNA and genomic sequences of the encoding LkLAC8 gene were isolated from the LACCASE expressed sequence tags of the Japanese larch transcriptome database using the rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). The cDNA was determined to be 1940 bp, with an open reading frame (ORF, 1734 bp) that encoded a protein of 577 AA. This protein contains four highly specific Cu2+ binding sites and 11 glycosylation sites, thus belonging to the LACCASE family. The deduced protein sequence shared an 89% identity with the PtaLAC from Pinus taeda. A real-time PCR analysis showed that the LkLAC8 transcript was expressed predominantly in mature xylem, with moderate levels in the immature xylem, cambium and mature leaves, the lowest in the roots. Lastly, the genomic sequences of LkLAC8 in 40 individuals from six naturally distributed populations of Japanese larch were amplified, and a total of 201 SNPs (103 and 98 mutation types of transition and transversion, respectively) were detected; the frequency of the SNPs was 1/19 bp. Nucleotide diversity among the six populations ranged from 0.0034 to 0.0053, which suggested that there were no significant differences among the populations. The LD analysis showed that the LD level decayed rapidly within the increasing length of the LkLAC8 gene. These results implied that LD mapping and association analysis based on candidate gene may be feasible for the marker-assisted breeding of new germplasms with low lignin in Japanese lar

关键词： Gene cloning LACCASE Larix kaempferi Linkage disequilibrium Real-time PCR Single nucleotide polymorphisms

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Changes of Soil Microbiological Characteristics After Solidago canadensis L. Invasion

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Agricultural Sciences in China 2011年第7期10卷 1064-1071页

作者： LIAO min xie Xiao-mei PENG Ying MA Ai-li Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition/Department of Resources Science College of Environmental and Resources Sciences Zhejiang University Hangzhou 310058 P.R.China Research Center for Eco-Environmental Sciences College of Environmental and Resource Sciences Zhejiang University Hangzhou 310058 P.R.China

The relationship between Solidago canadensis L. invasion and soil microbial communities was studied across the invasive gradients varying from 0 to 40, 80, and 100% coverage of S. canadensis. The results showed both soil microbial biomass C （Cmic） and N （Nmic） increased as the coverage of S. canadensis increased. Soil microbial quotient Cmic/Corg （microbial biomass C/organic C） tended to increase linearly with the coverage of S. canadensis. Soil basal respiration （BR） also showed a similar trend. The soil respiratory quotient qCO2 decreased with S. canadensis invasion, and remained at quite a constantly low level in the invasive soils. Sole carbon source utilization profiles analyses indicated that S. canadensis invasion tended to result in higher microbial functional diversity in the soil. Average utilization of specific substrate guilds was highest in the soil with S. canadensis monoculture. Principle component analysis of sole carbon source utilization profiles further indicated that microbial functional diversity in the soil with S. canadensis monoculture was distinctly separated from those soils in the native area and the ecotones. In conclusion, S. canadensis invasion improved soil microbial biomass, respiration and utilization of carbon sources, and decreased qCO2, thus created better soil conditions, which in turn were more conducive to the growth of S. canadensis.

关键词： sole carbon source utilization functional diversity microbial biomass microbial respiratory Solidago canadensis

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