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Wang S.-L.,Guangxi University for Nationalities | Zhang L.-Y.,Guangxi University for Nationalities | Huang Q.,Guangxi University for Nationalities | Huang Q.,Guangxi Key Laboratory of Chemistry and Engineering of Forest Products
Molecular Crystals and Liquid Crystals | Year: 2015

Three 2D novel lanthanide-based metallic coordination frameworks involving the 5-nitroisophthalic acid ligand were characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction, namely, [Er(NIPH)2(H2O)2](H2O)2 (1), [Eu4(NIPH)6(H2O)8](H2O)5 (2), and [Eu4(NIPH)6(H2O)6](H2O)4 (3), synthesized under hydrothermal conditions, self-assemble through Ln2[NIPH]2 building blocks to give a 2D coordination layer structure. The adjacent layers stack to form a 3D supramolecular framework through weak interactions, such as hydrogen bonding, π-π interactions, and lone pair-π interactions. However, in 1 and 2 formed 2D 4-connected (4,4) topological network. In addition, in this work the photoluminescent property of the compound 3 has been studied. Copyright © Taylor & Francis Group, LLC. Source


Lin G.-S.,Guangxi University | Ma C.-H.,Guangxi University | Duan W.-G.,Guangxi University | Cen B.,Guangxi University | And 2 more authors.
Holzforschung | Year: 2014

This work is aiming at the preparation of new bioactive compounds from a-pinene as starting material. To this purpose, the intermediates (disubstituted phenyl acylamino thioureas, class G) were cyclized to dithiadiazoles (class H). The intermediates and target compounds were analyzed by Fourier transform infrared, 1H nuclear magnetic resonance (NMR), 13C NMR, and electrospray ionization-mass spectrometry and elemental analysis. The bioassay experiments showed that the compounds G and H have herbicidal, fungicidal, and plant growth-regulating activities. The compounds 2,2'-dimethylphenyl thiadiazole and 3,3'-dimethylphenyl thiadiazole exhibited a growth inhibition activity of 72% and 68% against the root of rape (Brassica campestris L.) at a concentration of 100 μg ml-1 (60-79% inhibition level). The compound 4,4'-dichlorophenyl acylamino thiourea displayed an inhibition activity of 75% against Physalospora piricola at a concentration level of 50 μg ml-1 (60-79% inhibition level). © 2014 Walter de Gruyter GmbH, Berlin/Boston. Source


Zhou Z.,Beijing Forestry University | Xue W.,Beijing Forestry University | Lei F.,Guangxi Key Laboratory of Chemistry and Engineering of Forest Products | Cheng Y.,Beijing Forestry University | And 2 more authors.
Industrial Crops and Products | Year: 2016

Kraft green liquor (GL) mainly consisting of sodium carbonate and sodium sulfide are available from Kraft mills. Kraft GL combined with ethanol (Kraft GL-ethanol) was chosen to pretreat sugarcane bagasse for effective enzymatic hydrolysis. And the obtained lignins and cellulose rich fractions were characterized in detail. The highest lignin removal of 95.3% was observed at a pretreatment temperature of 160 °C, and approximately 70.8% of lignin was removed at the pretreatment temperature of 100 °C. The lignin removal with Kraft GL-ethanol pretreatment was higher than that with Soda GL-ethanol pretreatment at 140 °C. An FT-IR study of the isolated lignins showed that an increase in pretreatment temperature resulted in the cleavage of ester bonds. GPC results revealed that the molecular weight decreased with increasing pretreatment temperature. The 2D HSQC NMR data showed that the cleavage of β-O-4 became more severe with increasing pretreatment temperature from 80 to 160 °C. Fewer condensation reactions between lignin units occurred when the pretreatment temperature was above 100 °C. Moreover, the enzymatic hydrolysis efficiency of sugarcane bagasse increasing with increasing pretreatment temperature. The glucose yield reached 65.13% at a pretreatment temperature of 80 °C. The maximum glucose yield (98.26%) of sugarcane bagasse after 72 h of enzymatic hydrolysis was achieved at a pretreatment temperature of 160 °C. When lignin content was low in samples after pretreatment at 140-160 °C, the enzymatic hydrolysis efficiency of the substrate increased because the number of crystalline cellulose regions decreased. Scanning electron microscopy showed that the surfaces of Kraft GL-ethanol pretreated sugarcane bagasse were separated into individual fibers. In addition, contact angle analysis showed that the Kraft GL-ethanol pretreated sugarcane bagasse was more hydrophilic than untreated sugarcane bagasse. © 2016 Elsevier B.V. Source


Zhou Z.,Beijing Forestry University | Cheng Y.,Beijing Forestry University | Zhang W.,Nanjing Institute for the Comprehensive Utilization of Wild Plant | Jiang J.,Beijing Forestry University | Lei F.,Guangxi Key Laboratory of Chemistry and Engineering of Forest Products
BioResources | Year: 2016

Sugarcane bagasse was pretreated by green liquor combined with ethanol (GL-Ethanol) and green liquor combined with H2O2 (GL-H2O2). After 72 h of enzymatic hydrolysis, the glucose yields of sugarcane bagasse pretreated with GL-Ethanol and GL-H2O2 were 97.7% and 41.7%, respectively. The reason that GL-Ethanol was more effective than GL-H2O2 has not been elucidated clearly. In this study, the chemical composition of the sugarcane bagasse and chemical structure of the isolated lignins after these two pretreatment methods were characterized to investigate their correlation with the enzymatic hydrolysis of sugarcane bagasse. The removal of lignins with GL-Ethanol pretreatment was much higher than that of GL-H2O2. In addition, the decomposition of cellulose was lower in the case of GL-Ethanol than in that of GL-H2O2. According to Fourier transform infrared spectroscopy (FT-IR) and 1H-nuclear magnetic resonance (NMR) studies, the ester bonds (belonging to lignin-carbohydrate complex) could be broken during GL-Ethanol treatment. It was also found that the molecular weight of lignins obtained from GL-Ethanol was lower than that of lignins from GL-H2O2. Source


Yu H.-L.,Beijing Forestry University | Tang Y.,Beijing Forestry University | Tang Y.,Guangxi Key Laboratory of Chemistry and Engineering of Forest Products | Xing Y.,Beijing Forestry University | And 3 more authors.
Bioresource Technology | Year: 2013

A potential commercial pretreatment for furfural residues (FRs) was investigated by using a combination of green liquor and hydrogen peroxide (GL-H2O2). The results showed that 56.2% of lignin removal was achieved when the sample was treated with 0.6g H2O2/g-DS (dry substrate) and 6mL GL/g-DS at 80°C for 3h. After 96h hydrolysis with 18FPU/g-cellulose for cellulase, 27CBU/g-cellulose for β-glucosidase, the glucose yield increased from 71.2% to 83.6%. Ethylenediaminetetraacetic acid was used to reduce the degradation of H2O2, the glucose yield increased to 90.4% after the addition of 1% (w/w). The untreated FRs could bind more easily to cellulase than pretreated FRs could. The structural changes on the surface of sample were characterized by X-ray photoelectron spectroscopy. The results indicated that the surface lignin could be effectively removed during pretreatment, thereby decreasing the enzyme-lignin binding activity. Moreover, the carbonyl from lignin plays an important role in cellulase binding. © 2013 Elsevier Ltd. Source

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