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    30 March 2006, Volume 26 Issue 1 Previous Issue    Next Issue
    研究报告
    Chemical Composition and Antioxidant Components of Essential Oils from Leaves, Bark and Root of Myrica rubra
    ZHONG Rui-min;ZHANG Zhen-ming;WANG Yu-mei;ZENG Qing-xiao;PENG Hua-gui
    2006, 26 (1):  1-5. 
    Abstract ( 753 )   PDF (727KB) ( 758 )   Save
    Essential oils from leaves, bark and root of Chinese waxmyrtle (Myrica rubra var. astropurea Tsen), growing wild in Nanling National Nature Reserve, have been analyzed for their chemical composition and investigated for their antioxidant components. The GC-MS analysis as well as comparison of the Kovats retention indices (KI) of elution peaks with literature data were used for compound identification of the essential oils; TLC-screening method was used for analysis of antioxidant components in the oils. The essential oils of M. rubra bark and root are both dominated with 5-hydroxycalamenene (74.66% and 60.32%) and oleic acid (7.74% and 11.39%), respectively, whereas, the leaves oil is constituted mainly by 5-hydroxycalamenene (30.44%), caryophyllene (11.61%), isocaryophyllene (10.17%), (E)-nerolidol (9.57%) and oleic acid (4.40%), respectively. The composition matrixes of the essential oils of M. rubra leaves, bark and root express the differential complexity of secondary metabolites in this species. 5-Hydroxycalamenene is identified as the principal antioxidant in all three essential oils. However, the sesquiterpenes in leaves oil also show positive 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity in certain extent.
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    Promotional Effect of High Temperature Pretreatment on Enzymatic Hydrolysis of Xylan into Xylooligosaccharide
    GU Yang;YONG Qiang;YU Shi-yuan
    2006, 26 (1):  6-10. 
    Abstract ( 612 )   PDF (960KB) ( 668 )   Save
    The enzymatic hydrolysis residues of xylan was pretreated under high temperature from 160℃ to 180℃, then the filtrate of the pretreated suspension was enzymatically hydrolysed. Under the optimal condition of pretreatment for 30 min at 180℃, 42.54% of xylan residues could be decomposed efficiently and the yield of xylooligosaccharides(XOS)was 32.13% of the total carbohydrates of the supernatant. After enzymatic hydrolysis, the yield of XOS could be up to 84.93% of total carbohydrates of the supernatant.
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    Synthesis and Properties of Rosin-based Polyglucoside
    HU Li-hong;ZHOU Yong-hong;SONG Zhan-qian
    2006, 26 (1):  11-14. 
    Abstract ( 631 )   PDF (372KB) ( 645 )   Save
    Rosin-based polyglucoside (RPG), a kind of new nonionic surfactant, was synthesized from disproportionated rosin alcohol polyoxylethene ether(RP) through transacetalization, and reactions including synthesis of butyl polyglycoside and glycoside exchanging were studied. The suitable reaction conditions were obtained as follows: molar ratio of n-butanol to glucose 4:1,dosage of catalyst p-toluenesulfonic acid 0.5%(based on glucose mass), reaction temperature for the synthesis of butyl glucoside 110℃, reaction temperature for glycoside exchanging reaction 140℃, glucose conversion ratio upto 99.5%. Surface physicochemical properties of RP and RPG were measured. Relationships between surface physiochemical properties of the product and polymerization degree(n) of epoxy ethane were studied. Emulsifying power(EP) and foaming power(FP) of RPG were much better than those of RP.
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    Study on Preparation and Properties of Salt-tolerant Superabsorbent Resin through Inverse-suspension Polymerization
    CHEN Ri-qing;JIANG Yu;CHU Fu-xiang;ZHU Yong-nian;JIN Li-wei;LIN Ming-tao
    2006, 26 (1):  28-32. 
    Abstract ( 695 )   PDF (1039KB) ( 646 )   Save
    Superabsorbent resins with performance of good salt-tolerance were synthesized by inverse-suspension polymerization of acrylic acid in the presence of a crosslinking agent(N,N'-methylene bisacrylamide), an initiator (ammonium persulfate) and a chelant (ethylenediamine tetraacetic acid, EDTA). Influences of the amounts of crosslinking agent, chelant and initiator as well as degree of neutralization of acrylic acid on the absorption capacities toward water and salt solution were studied. It was found that the introduction of chelant EDTA promoted significantly absorption toward salt solution. It was also demonstrated that amounts of crosslinking agent, initiator and the degree of neutralization of acrylic acid influenced to a certain extent the absorption of resin toward 0.9% NaCl solution. Stable suspension could be obtained by using mixed non-ionic/anionic oligomers as surfactants. The resulted resins showed absorption capacities of more than 670 g/g toward water and 170 g/g toward 0.9% NaCl solution respectively.
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    Study on Application of Urushiol-metal Polymer for Catalytic Synthesis of Isoamyl Acetate
    LI Guo-xiang;DAN You-meng;YANG Chun-hai;SHI Bo-an
    2006, 26 (1):  15-18. 
    Abstract ( 612 )   PDF (708KB) ( 697 )   Save
    A series of urushiol-metal polymers were synthesized and their properties were characterized by IR method,in which urushiol-Fe-C polymer was used as catalyst to synthesize isoamyl acetate. Factors affecting esterification yield such as material ratio,time of reaction and catalyst have been studied. The optimum conditions are as follows: material ratio of isoamyl alcohol to glacial acetic 0.6:1; dosage of catalyst 2.3%-3.4% of isoamyl alcohol; reaction time 3 h; yield of isoamyl acetate(IA) 88%.The purity of product is 99.5%. This catalyst has the advantage of less corrosion and can be reused.
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    Characterization and Properties of Urushiol-praseodymium Polymer
    CHEN Qin-hui;LIN Jin-huo
    2006, 26 (1):  19-22. 
    Abstract ( 567 )   PDF (761KB) ( 653 )   Save
    Urushiol praseodymium polymer (PUPr), prepared by thermo-polymerization in non-aqueous medium was characterized by elemental analysis, IR, XPS, TG, etc, which indicated that the formation of PUPr was attributed to the coordination between urushiol and PrCl3 followed by cross-linking reaction among the side chains of urushiol. Resulted from the unsaturated coordination of praseodymium, PUPr was reactive for catalyzing the polymerization of olefinic monomers such as butyl α-methacrylate in the presence of sodium sulfite.
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    Synthesis Mechanism and Chemical Characterization of Polyprenyl Phosphate
    WANG Cheng-zhang;ZHENG Guang-yao;GAO Cai-xia;ZHANG Si-fang;CAO Zhi-qing;SHEN Zhao-bang
    2006, 26 (1):  23-27. 
    Abstract ( 660 )   PDF (779KB) ( 584 )   Save
    Polyprenols(C75-C110)of purity over 87.2% were separated and prepared from leaves of Gingkgo biloba L. Polyprenyl phosphate dichlorate was synthesized by choosing phosphorus oxychloride (POCl3) as phosphate,and was converted into polyprenyl phosphate with triethanylamide as hydrolytic reagent with yield more than 65%.The molar ratio of polyprenols to POCl3 was 1:5-10.Phosphate ester reaction temperature was below 10℃,and hydrolysis for 20 h at room temperature.The hydrolysate was purified by silicon gel chromatography and polyprenyl phosphate was obtained by HPLC,and its chemical structure was identified as polyprenyl monophosphate with IR,1HNMR,13CNMR and HRMS.
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    Effects of Ozone Treatment on Surface Characteristics and Cr6+ Adsorption Capacity of Activated Carbon
    LIU Shou-Xin;SUI Shu-Juan;SUN Cheng-Lin
    2006, 26 (1):  33-36. 
    Abstract ( 610 )   PDF (733KB) ( 744 )   Save
    Effects of ozone treatment on structure of surface functional groups, pore structure and Cr6+ adsorption capacity of activated carbon were evaluated. Boehm titration method and FT-IR techniques were used to characterize surface properties. Liquid nitrogen adsorption isotherm method was used to characterize pore structure. The results revealed that suitable ozonation can improve Cr6+ adsorption capacity of activated carbon significantly. The structure of surface functional groups and pore structure of activated carbon were changed due to ozonation. Alkaline sites were oxidized into acidic sites. The increase of surface acidity was the main cause of higher Cr6+ adsorption capacity for the ozonated activated carbon.
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    Synthesis and Degradation of Copolymer of Styrene and Tung Oil Initiated by Self-oxidization of Tung Oil
    PU Xia;ZHANG Xing-hua
    2006, 26 (1):  37-40. 
    Abstract ( 688 )   PDF (768KB) ( 625 )   Save
    Tung oil can be copolymerized with styrene without initiator. This polymerization mechanism is based on its self-polymerization characteristic after being oxidized in air. The special mechanism of free-radical polymerization was explored by several modern analytical ways. Degradation of the product was also investigated. The mechanism is that after tung oil has been oxidized, peroxides which include hydrogen peroxide or 1,4 ring-peroxide can be formed, then peroxybonds break and initiate copolymerization between styrene and tung oil. The way of 1,4-addition polymerization plays a primary role in the reaction. Experimental results showed that the copolymer had potential properties of bio-degradation. Weight ratio of tung oil to styrene between 1:3 and 1:4,especially 1:4, was appropriate for both polymerization and degradation.
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    NMR Studies on Chemical Structures of Polysaccharides of the Main Plant-gum Resources in China
    JIANG Jian-xin;ZHU Li-wei;AN Xin-nan;ZHANG Wei-ming
    2006, 26 (1):  41-44. 
    Abstract ( 626 )   PDF (759KB) ( 699 )   Save
    Polysaccharides isolated from seeds of fenugreek(Trigonella foenum-graecum),China honeylocust (Gleditsia sinensis), smalleaf honeylocust (G. microphyllfa) and tara (Caesalpinia spinosa) are composed of D-galactose and D-mannose, which are similar to galactomannan from guar gum. Structural studies are performed by GC, 1HNMR and 13CNMR. All galactomannans possess molecules having main chains consisted of (1→4)-linked β-D-mannose residues, with different proportions of side chains consisted of single α-D-galactose residue linked to the main chain by (1→6)-bond. Ratios of galactose to mannose of the above polysaccharides are 1:1.2, 1:2.5, 1:3.2 and 1:2.4,respectively (guar gum 1:1.6). Molecular weights (MV) are found to vary from 206000 (smalleaf honeylocust) to 343900 (tara). Melting points are situated between 263-272℃(Mv of guar gum is 430600).
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    Study on Immobilization of Amylase on Calcium-complexed Polymerized Rosin
    LAN Hong-yun;LEI Fu-hou;MO Kun;TANG Pei-ying
    2006, 26 (1):  45-48. 
    Abstract ( 549 )   PDF (679KB) ( 683 )   Save
    A series complexes of polymerized rosin (PR) or grafted copolymers of polyvinyl alcohol with PR (PVA-g-PR) were synthesized. These complexed polymerized rosins were used as carriers for immobilizing amylase and their properties were investigated. The experimental results showed that amylase immobilized on calcium-complexed PR (PRCa2+) had good reusability, the activity was retained 30.8% after being used 5 times. Optimum operating temperature was 70℃ for immobilized amylase which was 30℃ higher than that of free amylase. Optimum pH value was 5.0 for immobilized amylase and 6.0 for free amylase. Km (Michaelies-Menten constant) of immobilization amylase was 1.69×10-2 kg/L, which is lower than 2.90×10-2 kg/L of free amylase.
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    Study on Pyrolysis and Charring of Coconut Shell by Thermal Analysis
    NING Ping;YANG Yue-hong;PENG Jin-hui;ZHANG Shi-min
    2006, 26 (1):  49-52. 
    Abstract ( 885 )   PDF (846KB) ( 797 )   Save
    Coconut shell is an excellent raw material for preparation of activated carbon. Studies on weight loss, heat effect and heat stability of coconut shell were carried out by simultaneous measurements of thermogravimetry(TG) and differential thermal analysis(DTA), mechanisms of pyrolysis and charring of coconut shell were analyzed. The influences of pyrolysis temperature and heating rate on charring yield and decomposition rate of coconut shell were also explored. According to experimental results, all curves from thermal analysis showed two weight loss stages under the conditions of five different heating rates. Temperature range of coconut shell pyrolysis is from 200 to 410℃.Controlling weight loss of the second stage is the key for pyrolysis and charring.In a certain degree, increasing heating rate is helpful for pyrolysis of coconut shell. Under the conditions of optimum heating rate at 20℃/min, enthalpy of pyrolysis reached 792.15 kJ/g and weight loss was only 31.925%.The optimum final pyrolysis temperature was 575℃.This study provides theoretical basis for optimizing charring technology of coconut shell.
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    Study on Adsorption and Purification of Azadirachtin A by Macroporous Resin
    WANG Qiu-feng;SONG Zhen-qian
    2006, 26 (1):  53-56. 
    Abstract ( 537 )   PDF (797KB) ( 652 )   Save
    Five types of macroporous resin were studied in order to compare their performances in absorbing and desorbing azadirachtin A. XAD-1180 was considered as the optimal macroporous resin for azadirachtin A. The dynamic adsorption and desorption conditions for purification of azadirachtin A were studied. The appropriate adsorption conditions were: concentration of azadirachtin A 2 mg/mL in 30% methanol solution, flow rate 1 BV/h, amount of saturated adsorption toward azadirachtin A 4-5 BV. The desorption conditions were: gradient elution with 50%,60% and 70% methanol solution at flow rates 1 and 0.5 BV/h. The purity of azadirachtin A purified by XAD-1180 for one time was 85.15%.Its purity was 93.1% when purified twice. The purified product was further confirmed to be azadirachtin A by HPLC-MS.
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    Study on Polyurethane Adhesive of Wood(Ⅰ)--Effects of Chemical Constituents on Mechanical Properties of Adhesive
    WANG Zheng;WANG Zhi-ling;REN Yi-ping
    2006, 26 (1):  57-61,7. 
    Abstract ( 578 )   PDF (823KB) ( 538 )   Save
    A single-component polyurethane adhesive for bonding wood curable at room temperature under moist condition was synthesized from methylene-bridged polyphenylene polyisocyanate (PAPI) and polyether polyol. Effects of chemical constituents on mechanical properties of adhesive were studied.The results showed that press shearing strength of poplarwood (Populus×euramericana cv.) board bonded with this adhesive was 60% higher than that with MDI.Using polyethere oxide diols(PED)of relative molecular weight(MW) 800,1000 and 2000,with polypropylene oxide triols of MW 300 and 3000(N303 and N330),and polytetramethylene ether glycol-propylene oxide diol(NG220),at optimal ratio, catalyzed by compounded catalyst of modified amine and organic stannum, dry and wet press shearing strengths and curing speed of the adhesion could be efficiently incresed, especially wet wood failure could reach 100% and 90% for bonding poplarwood and oakwood respectively. The formation of —NHCOO— between hydroxyl groups of polyol and isocyanate groups of PAPI was verified by FT-IR spectroscopy.
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    Study on Enzymatic Extraction of Isoflavone from Pueraria (Pueraria lobata) Root Residue
    SHI Ying-ying;XUE Pei-jian;XIA Li-ming
    2006, 26 (1):  62-64. 
    Abstract ( 671 )   PDF (524KB) ( 709 )   Save
    Pueraria lobata(Willd.)Ohwi is a kind of raw material to produce starch in China. The root residue of pueraria from pueraria-starch manufactory still contains some isoflavone which is a kind of phytoestrogen with important physiological effects. By pretreating pueraria root residue with cellulase or xylanase before ethanol extraction, the total yield of isoflavone could be efficiently increased. The optimal cellulase dosage was 10 FPIU/g pueraria root residue and the suitable cellulase treatment time was 12 h. Total yield of isoflavone was 1.36 times as that by normal ethanol extraction. For pretreatment of pueraria root residue with xylanase, the optimal xylanase dosage was 300 IU/g residue for 6 h.Total yield of isoflavone was 1.52 times as that by regular ethanol extraction. It was proved that cellulase and xylanase could cooperate with each other to enhance extraction efficiency. When pueraria root residue was pretreated with both cellulase (7.5 FPIU/g residue) and xylanase (300 IU/g residue) for 6 h, total yield of isoflavone reached 138 mg/10 g pueraria root residue, which was 1.64 times as that by regular ethanol extraction.
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    Effect of Carbonization Temperature on Microporous Structure of Charcoal from Chinese Fir Wood
    HUANG Biao;CHEN Xue-rong;JIANG Mao-sheng;TANG Xing-ping;GAO Shang-yu
    2006, 26 (1):  70-74. 
    Abstract ( 492 )   PDF (1232KB) ( 756 )   Save
    By means of scanning electronic microscopy(SEM), automated specific surface-area and pore-size analysis, microporous structure of charcoal from Chinese fir wood carbonized under different temperatures was studied. With emphasis on formation of micropore and variation pattern, pore-size distribution, specific surface area and characteristics of pores were observed and analyzed. Results showed that both specific surface area and specific pore volume of charcoal increased with increased carbonization temperature.Carbonized material from higher temperature possessed more developed structure and larger specific surface area.Under high temperature, microporous structure was improved by burning off orderless carbon. By means of SEM, observation on state of microstructure of carbonized material showed that with increased carbonization temperature,amount of surface sediment on tracheid wall of carbonized material reduced and its particlesize became smaller,the layers of pits were gradually destroyed, and pit pores were opened. Observation on state of electric discharge under SEM showed that conductivity of carbonized material was increased with increase of carbonization temperature.
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    Research on Pyrolysis Properties of Sugarcane Bagasse
    XIAN Ping;LU Yu;WANG Xiao-ying;ZHONG Li-ying
    2006, 26 (1):  65-69. 
    Abstract ( 674 )   PDF (372KB) ( 523 )   Save
    In the experiment using steam as gasification agent, the conversion of biomass consists of two processes, pyrolysis and gasification, which produce gases with main constituents of H2, CO, CO2, CH4, tar and carbon. The yield and distribution of products in pyrolysis depend on temperature, heating rate and grain size. According to the experiment, higher temperature and smaller size of feedstock will be propitious to produce gas with higher heating value. The impact of particle size can be interpreted by the theory of non-homogeneous reaction. Under the operating conditions of pyrolysis, temperature is the decisive factor in the reacting process, and the change of heating rate does not have much impact on the gasification. Under the optimum conditions,the created gas with high heating value of 10 MJ/Nm3 and yield of 1.7 m3/kg were obtained.
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    Preparation and Antimicrobial Activity of Grafted Polymer of Konjac Glucomannan with Methacryoxylethyl Benzyl Dimethyl Ammonium Chloride
    XU Xia;YANG Qin-huan;LU Ai-xia;LI Zheng-jun;HE Zhuang-zhi;LIN Fang;ZHANG Ting-you
    2006, 26 (1):  75-78. 
    Abstract ( 592 )   PDF (700KB) ( 738 )   Save
    The grafted polymer of konjac glucomannan(KGM) with methacryloxylethyl benzyl dimethyl ammonium chloride (KGM-g-DMAE-BC) had been prepared and its antibacterial activity was investigated. The optimum technological conditions were: reaction time 3 h, temperature 70℃, m KGM:, gram-positive bacteria (Staphylococcus aureus) and fungus (Candida albicans), at becteriostatic rates of 99.99%, 94.26%, 99.99%, respectively.
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    Research on Strengthening Effect of Cationic Polyacrylamide Emulsion toward Wood Pulp
    LI Jian-wen;QIU Hua-yu;ZHAN Huai-yu
    2006, 26 (1):  79-82. 
    Abstract ( 673 )   PDF (977KB) ( 548 )   Save
    Water-in-water type cationic polyacrylamide (CPAA) emulsion was synthesized through free-radical copolymerization of acrylamide and dimethyl diallyammonium chloride (DDAC).The impacts of application conditions,such as dosage of CPAA emulsion, reaction time, amount of aluminum sulfate, pH value of wood pulp and stirring speed on its reinforcing effect toward bleached wood-pulp were explored. As a result, compared to paper characteristics without CPAA emulsion, breaking length and tearing index of paper sheets of wood pulp were increased respectively by 28.7% and 12.4% at charge of CPAA emulsion 0.8% (on oven dry pulp), reaction time 10 min, pH value 7.0, dosage of aluminum sulfate 0.5% (on oven dry pulp) and stirring speed 150 r/min. The expected molecular structure of CPAA made in our lab was identified from its infrared spectrum. Its reinforcing mechanism toward bleached wood pulp was also explored elementarily by comparing photographs from environmental scanning electron microscopy (ESEM) between paper sheets with and without CPAA emulsion treatments.
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    Partitional Behaviors of Flavones of Persimmon Leaves in Two-phase Aqueous System
    ZHAO Xiao-li;YUE Hong;ZHANG Ying;LI Xiao-yin
    2006, 26 (1):  83-86. 
    Abstract ( 549 )   PDF (580KB) ( 847 )   Save
    Effective extraction of flavones from persimmon leaves is an important technique in bioresearch. In the present study, extraction and purification of flavones of persimmon leaves were carried out simultaneously by using an aqueous partitioning method. This two-phase aqueous system was prepared by dissolving suitable amounts of polyethylene glycol(PEG)and(NH4)2SO4 in aqueous solution. Flavones of persimmon leaves were recovered with optimum high yield and high concentration in the upper polymer-rich phase when 25% PEG 600and25% (NH4)2SO4 were applied. The optimum extraction conditions were pH value 11, MgCl2 3% and temperature 25℃.
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    Study on Separation and Purification of Total Flavones of Hawthorn Leaves by Macroporous Adsorption Resins
    ZHANG Li-ming;LI Chun-lian
    2006, 26 (1):  87-90. 
    Abstract ( 510 )   PDF (756KB) ( 871 )   Save
    Adsorption and desorption characteristics of macroporous adsorption resins ADS-5, ADS-8, ADS-17, NKA-9, D-101 and AB-8 toward flavones of hawthorn leaves were investigated.Based on static adsorption, the best macroporous adsorption resin was chosen to carry out dynamic adsorption experiments. The result showed that the best resin to separate and purify total flavones of hawthorn leaves was D-101. The preferred adsorbing and desorbing conditions were determined through studying the affecting factors on utilization efficiency of D-101 resin at room temperature.
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    Fibre Morphology and Anatomical Structure of Sandlive Willow ( Salix psammophila)
    XU Feng;JONES-Gwynn L L;SUN Run-cang
    2006, 26 (1):  91-94. 
    Abstract ( 726 )   PDF (851KB) ( 724 )   Save
    The present study was undertaken to investigate fibre morphology and anatomical structure of sandlive willow (Salix psammophila C. Wang et Ch.Y.Yang). Results from light microscopy (LM), scanning electron microscopy (SEM), and Kajaani FS200 analysis showed that anatomical features of S.psammophila exhibited distinct growth ring boundaries exclusive uniseriate rays, diffuse-porous vessels in solitary arrangement, and diversified perforation plates and intervessel pits.The cells are of four types: vessel, fibre, ray parenchyma and axial parenchyma. Fibres make up 60%-70% of total cells. Although mean fibre length of S. psammophila is 0.52 mm, this fiber is beneficial to pulping and papermaking according to its fine fibre morphology.
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    Study on Characteristics of Bio-membrane in Bio-contact Oxidation Treatment of Wastewater from Regenerated Papermaking
    MA Yong-wen;LIU Yang;WAN Jin-quan;ZHOU Shen-qiao
    2006, 26 (1):  95-98. 
    Abstract ( 563 )   PDF (1024KB) ( 773 )   Save
    Research on bio-membrane in treating wastewater from regenerated papermaking by bio-contact oxidation was carried out, and the result indicated that active thickness of the bio-membrane was between 70 and 100 μm. During the course of membrane formation, filamentous bacteria are the main biota, with less flagellated protozoan and ciliates, so that the activity of the membrane is relatively poor. In case of normal running, fixed ciliates are the dominant protozoan, the biota of the bio-membrane is relatively stable, and the removal rate of COD is kept steadily around 88%.
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    Syntheses of Emulsions of Gelatin-grafted Polymer and Its Effect on the Intensity of Sheets
    REN Jun-li;QIU Hua-yu;SUN Run-cang
    2006, 26 (1):  99-103,. 
    Abstract ( 731 )   PDF (1081KB) ( 657 )   Save
    A series of emulsions of gelatin-grafted polymer were synthesized by polymerization of gelatin with acrylamide (AM) and methacryloyloxyethyl trimethylammonium chloride (DMC) using oxidation-reduction initiator blended with non-ionic emulsifier and cationic emulsifier at different ratios.Effects of feeding method of monomers,kinds and dosages of emulsifiers on the reaction were studied in detail. The results showed that this emulsion could improve physical strength of wood pulp handsheets obviously when all monomers were added simultaneously. The optimum proportion of non-ionic emulsifier (OP) to cationic emulsifier (Y1) m(OP):m(Y1) was 2.5:7.5. Compared with the control sample, breaking length, tearing index,burst index and folding endurance were increased by 23.9%, 7.6%, 21.2% and 186%, respectively, when the dosage of emulsion was 1.0% ( based on o. d. pulp).
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    Study on Chemical Structure Characteristics of Wheat Straw Lignin from Enzymatic Hydrolysis-mild Acidolysis
    WU Shu-bin;LI Meng-shi
    2006, 26 (1):  104-108. 
    Abstract ( 822 )   PDF (851KB) ( 767 )   Save
    The enzymatic hydrolysis-mild acidolysis lignin (EAL) of wheat straw was isolated through a novel lignin preparation procedure, which has good presentation of the native lignin in fibre wall. Contents of functional groups and arylglycerol-β-arylether bonds, linkage types and dibenzodioxocins (DBDO) structures of EAL were studied intensively through elementary analysis, quantitative 31PNMR and method of derivatization followed by reductive cleavage (DFRC).
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    综述评论
    Proanthocyanidins: Absorption, Metabolism and Bioavailability
    LUO Xin;YAO Kai;JIA Dong-ying;HE Qiang
    2006, 26 (1):  109-115. 
    Abstract ( 972 )   PDF (406KB) ( 627 )   Save
    Proanthocyanidins (PAs), as a predominant group of both flavonoids and polyphenols, are less studied than other simpler compounds due to their large molecular size, complicated structure and polymeric nature, though they play major roles in both human diet and animal forages and have noticeable health effects. In this review, the absorption and bioavailability of PAs are compared among catechin (CC) monomers, PA dimers/trimers and larger PA oligomers. The metabolic fate of PAs is summarized, and one possible mechanism of PA degradation in vivo is discussed, based on some evidence of a preliminary depolymerization. Regarding to various physi-ological potential of PAs, plasma circulation and cellular uptake of these compounds and their metabolites are also briefly referred. These help to figure out to what extent the monomers, dimers/trimers, larger PA polymers, or their metabolites directly contribute to the multiple biological effects in vivo, so as to demonstrate the health effects of PAs, and elucidate the relevant mechanisms.
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    Comparison of Technologies of Extraction and Purification of Chlorogenic Acid from Honeysuckle (Flos lonicerae)
    SHANG Zhi-nan;NING Zheng-xiang
    2006, 26 (1):  116-120. 
    Abstract ( 714 )   PDF (983KB) ( 841 )   Save
    This paper mainly introduced the technologies of extraction and purification of chlorogenic acid from honeysuckle (Flos lonicerae) in recent ten years. Particular analyses, discussions and comparisons of various methods of extraction and purification were described. In view of the feasibility of practical application, a reasonable operational technology was suggested.
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    研究简报
    Primary Study on Low-molecular-mass Products from Electro-oxidation of Lignosulfonate
    YANG Wei-dong;Ding Ming;ZHANG Jin-ping;WANG Jing-wen
    2006, 26 (1):  121-123. 
    Abstract ( 585 )   PDF (493KB) ( 834 )   Save
    Electroxidation of lignosulfonate in aqueous alkaline solution using lead dioxide electrode was carried out at temperature 25℃, electric current density 50-70 mA/cm2 and voltage 2.0-2.5 V. Degradation products were extracted from the aqueous solution and analysed through HPLC. Results show that lignosulfonate is cleaved electrolytically into 6 low-molecular-mass products, namely: vanillin, springaldehyde, syringic acid, 4-hydroxybenzaldehyde, acetophenone and benzoic acid.
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    Study on Production of Xylo-oligosaccharides from Xylan Hydrolyzed by Selectively Purified Endo-β-xylanase
    MAO Lian-shan;YONG Qiang;SONG Xiang-yang;YAO Chun-cai;YU Shi-yuan
    2006, 26 (1):  124-126. 
    Abstract ( 679 )   PDF (484KB) ( 713 )   Save
    Studies on removing exo-β-xylosidase by ultrafiltration from xylanase synthesized by Trichoderma reesei Rut C-30 and production of xylo-oligosaccharides from xylan hydrolyzed by selectively purified xylanase were investigated. It was found that ultrafiltration could remove completely exo-β-xylosidase from xylanase system. The liquid of permeation of ultrafiltration was identified to be homogeneous by sodium dodecylsilfate-polyacrylamide gel electrophoresis (SDS-PAGE) chromatography, and the product of enzymatic hydrolysis from the liquid of permeation of ultrafiltration was wholly xylo-oligosaccharides. The yield of xylo-oligosaccharides increased from 26.83% to 54.22% when enzymatic hydrolysis time was increased from 2 h to 10 h. However, during the production of xylo-oligosaccharides from xylan hydrolyzed by coarse xylanases, the yield of xylo-oligosaccharides dropped from 17.97% to 11.12%, when enzymatic hydrolysis time was increased from 2 h to 10 h. It was concluded that the effective conversion of xylan was enhanced and the ratio of xylo-oligosaccharides to xylose was markedly increased with this method, and this teachnique would provide a new way for xylo-oligosaccharides production.
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    Study on the Antitumor Activities of Different Tea
    LUO Yi-fan;CHEN Jian-jing;GUO Zhen-fei;XU Xuan;LING Cai-jin;TANG Hao
    2006, 26 (1):  127-128. 
    Abstract ( 675 )   PDF (420KB) ( 482 )   Save
    Chemical compositions and their contents of catechins in 4 different tea were determined by spectrophotometry and high performance liquid chromatography (HPLC). The results show that chemical compositions, contents of catechins and their ratios were greatly different in different varieties of tea, which are the substance bases that determine the antitumor function of tea.
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    Studies on Supercritical CO2 Extraction and Chemical Components of Oil from Evening Primrose Seeds
    OUYANG Hui;YU Ji;ZHANG Yong-kang;CHEN Xiao-yuan
    2006, 26 (1):  129-131. 
    Abstract ( 540 )   PDF (601KB) ( 512 )   Save
    The technic of extracting oil from evening primrose (Oenothera biennis L.cv."Laershan-1")seeds was studied by supercritical CO2 extraction in orthogonal experiments. The optimal conditions were: extraction pressure 35 MPa, extraction temperature 30℃, separation temperature 35℃ and extraction time 60 min. Under optimal conditions, the yield is 23.1%. According to GC analysis, the main unsaturated fatty acid components of the oil include oleic acid,linoleic acid and γ-linolenic acid. Total content of unsaturated fatty acids is 91.93%. Analyses of physical-chemical parameters showed that acid number of the oil is very low, only 1.1 mg/g.
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    Synthesis of Butyraldehyde 1,2-Propanediol Acetal Using Solid Superacid as Catalyst
    YANG Shui-jin;XIA Jia
    2006, 26 (1):  132-134. 
    Abstract ( 537 )   PDF (591KB) ( 575 )   Save
    Butyraldehyde 1,2-propanediol acetal was synthesized from butyraldehyde and 1,2-propanediol catalyzed by solid superacid SO42-/TiO2-MoO3. The experimental results showed that catalytic activity of the catalyst was improved through addition of MoO3 into SO42-/TiO2. Influencing factors of the synthesis were discussed and the optimums reaction condition was found to be: molar ratio of butyraldehyde to 1,2-propanediol 1:1.5, dosage of catalyst 0.5% of feed stocks, and reaction time 45 min. SO42-/TiO2-MoO3 is an excellent catalyst for synthesizing butyraldehyde 1,2-propanediol acetal to improve the yield up to 87.5%.
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