Table of Content

30 December 2002, Volume 22 Issue 04 Previous Issue    Next Issue

研究报告

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SYNTHESIS AND PROPERTY OF A WATER SUPERABOSORBENT OF POLY(STARCH-ACRYLIC ACID-ACRYLAMIDE) COMPLEX RESIN LONG Jian-ying;SONG Zhan-qian 2002, 22 (04):  1-4.  Abstract ( 607 )   PDF (470KB) ( 953 )   Save Using sodium bisulfite and ammonium persulfate,N,N-methylene bisacrylamide as redox initiator and crosslinking agent respectively,a water superabsorbent capable of absorbing more than 1 800 g/g deionized water and possessing good gel strength was prepared by synthesizing grafted starch acrylic acid acrylamide in the clay suspension for the first time.More than 1 000 g deionized water has been absorbed by the superabsorbent in 5 min,and water absorbence of this superabsorbent decreased slowly with the increase of temperature.Influences of kinds of clay,configuration of starch and amounts of clay and crosslinking agent on the properties of the resin are also discussed. Related Articles | Metrics

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TCF BLEACHING PROPERTIES OF WHEAT-STRAW PULPS PRE-TREATED BY ENZYME IN A LACCASE-MEDIATOR SYSTEM HAN Shan-ming;FANG Gui-gan;SHEN Kui-zhong;LIU Ming-shan;Jean-Claude SIGOILLOT;Marther ASTHER 2002, 22 (04):  5-9.  Abstract ( 711 )   PDF (927KB) ( 754 )   Save A laccase mediator system was applied on pre treatment of wheat straw pulps.The characteristics of enzyme treated pulps and their bleaching abilities by several total chlorine free(TCF) bleaching sequences were investigated.The results show that bio treatment of laccase mediator system can enhances not only optical properties but also physical strength of the treated pulps.After laccase treatment,brightness gain of pulp was up to 12.9 units (%,ISO).Using an OEPP bleaching sequence,the bleached pulp brightness of laccase treated pulps was higher by 14 units than that of bleached initial pulp.Bleached by a QPP bleaching sequence,laccase treatment could improve the bleached pulp brightness by 18.3 units more than that from initial pulp.After QPaP sequence bleaching,brightness of laccase treated pulp was of 8.1 units higher than that of bleached initial pulp.If the target brightness was the same,laccase treatment could save much bleaching chemicals,that was beneficial to reduce the load of bleaching effluence.The strength of bleached laccase treated pulp was similar to or a little bit lower than that of bleached initial pulp. Related Articles | Metrics

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STUDY ON α-PINENE ISOMERIZATION CATALYZED BY SO42-/ZrO2 SOLID SUPERACID WANG Ya-ming;XIE Hui-ding;HUANG Wei-li 2002, 22 (04):  10-14.  Abstract ( 722 )   PDF (951KB) ( 811 )   Save Effects of conditions for preparation ofSO42-/ZrO2 solid superacid, such as concentration of H2SO4, calcination temperature,calcination time with respect to its catalytic activity were studied.Results showed that as calcination temperature increased,catalytic activity ofSO42-/ZrO2 catalysts decreased under lower concentration of H2SO4 and calcination time 3 h.Catalytic activity was not obviously affected by calcinations time under lower concentration of H2SO4 and lower calcination temperature,while products distribution was affected to a certain extent.SO42-/ZrO2 solid superacid was used to catalyze α pinene isomerization at 130℃±2℃,mass part of catalyst 4% to give results of α pinene conversion at 88.8%,and camphene selectivity at 55.4%.Hammett constants of several catalysts were measured,and surface properties ofSO42-/ZrO2 catalysts were tested by TEM. Related Articles | Metrics

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THERMOMECHANICAL ANALYSIS OF LIGNIN DERIVED FROM HIGH PRESSURE EXTRACTION OF WOOD QIAN Xue-ren;LI Jian 2002, 22 (04):  15-18.  Abstract ( 602 )   PDF (471KB) ( 700 )   Save Thermal fluidity of lignin seems to be necessary for various applications of lignin in industrial fields,such as transformation of lignin into membranes,fibers and plastics.Thermal behavior of lignin derived from near critical and high pressure ethanol water extraction of Larix gmelinii Rupr.wood was investigated by thermomechanical analysis(TMA) in this study.Result showed that thermal properties of high pressure extracted lignin were markedly superior to those of kraft lignin.The former had a lower glass transition temperature,and had partially fusible characteristics.Thus,high pressure extracted lignin could directly be converted to fusible materials,unlike kraft lignin requiring chemical modification. Related Articles | Metrics

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STUDY ON ENZYMATIC HYDROLYSIS OF XYLAN IN MEMBRANE REACTOR YANG Fu-guo;FANG Zheng;WANG Wei;XU Yong;YU Shi-yuan 2002, 22 (04):  19-22.  Abstract ( 621 )   PDF (565KB) ( 554 )   Save Hydrolysis process of xylan by xylanase in membrane reactor was studied under conditions of xylan concentration 30.0 g/L,operating pressure 16 kPa,feed rate 400 mL/min,enzymatic hydrolysis time 12 h,pH value 5.0 and 48℃.Results showed that total sugars yield from enzymatic hydrolysis xylan was 60.10%;degree of polymerization(DP) of unhydrolyzed xylan was about 10,DP was not changed by use of alkaline;total sugars yield from enzymatic hydrolysis of unhydrolyzed xylan was 7.50%. Related Articles | Metrics

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PREPARATION AND PROPERTY OF SODIUM LIGNOSULFONATE FROM DAHURIAN LARCH BARK RESIDUE AFTER TANNIN EXTRACTION YANG Yi-qin;LI Zhong-zheng 2002, 22 (04):  23-26.  Abstract ( 592 )   PDF (616KB) ( 612 )   Save Sulfonation of Dahurian larch(Larix gmelinii Rupr.) bark residue after tannin extraction was studied in this paper.Results show:suitable conditions of sulfonation were as follows:alkali dosage 13%(NaOH),sodium sulfite 60%-70%(based on alkali dosage),temperature 140-150℃,time 2 h.Lignosulfonate with good property as additive in concrete and as surfactant in oil field can be obtained.This study provided scientific basis for efficient use of bark residue. Related Articles | Metrics

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STUDY ON PORE STRUCTURE OF WOODCERAMICS LI Jian;LI Shu-jun 2002, 22 (04):  27-30.  Abstract ( 684 )   PDF (772KB) ( 1030 )   Save Woodceramics(WCS) is a new porous carbon material of low cost and excellent properties,which is obtained by carbonization of middle density fiberboard impregnated with 40% PF resin.Pore structure was measured by low temperature N2 absorption method.Woodceramics which is obtained by carbonization of middle density fiberboard impregnated with fireretardant and 20% PF resin is called P-WCS.Results showed that adsorption properties of traditional charcoal were very poor because of not being activated.Micropore area of WCS was 314.16 m2/g,and micropore volume was 0.126 2 mL/g,which are much more than those of charcoal.Average diameter of WCS was 1.598 nm,which is much less than that of charcoal.PF resin brought lots of micropores into the woodceramics to have adsorption properties much better than those of charcoal. Related Articles | Metrics

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AQUEOUS AMMONIA-CAUSTIC POTASH PULPING OF RICE STRAW HUANG Guo-lin;CHEN Zhong-sheng;ZHANG Cheng-fang 2002, 22 (04):  31-36.  Abstract ( 791 )   PDF (734KB) ( 1064 )   Save An advanced pulping technology was studied in which ammonium hydroxide with less amount of potash alkali was used for cooking rice straw.Effects of pulping condition such as composition of cooking liquor,liquor solid ratio,maximum cooking temperature and time were studied systematically by experiments to obtain suitable technological condition.Results indicated that rate of delignification is 84.12% and pulp yield is 38.12% under the pulping conditions.Structural changes of lignin were detected by IR.Good prospect has been laid for utilizing black liquor containing nitrogen,phosphorus,potassium and ammoniacal lignin as fertilizer for agricultural production,and the problem of environmental pollution of black liquor would be solved thoroughly. Related Articles | Metrics

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PREPARATION OF LIGHT-COLORED ROSIN ESTER AND STUDIES ON MECHANISM OF COLOR-LIGHTENING CAO De-rong;WEI Xiao-hui;CHEN Jiu-ji;LIN Li;XU She-yang 2002, 22 (04):  37-39.  Abstract ( 729 )   PDF (417KB) ( 1079 )   Save Light colored rosin ester with Gardner color 2-4 was prepared by reacting rosin with alcohol in the presence of a new CLC catalyst.Analysis of the product showed that relative content of dehydroabietic acid and hydrogenated resin acids increased from 0 in rosin to 30% and 22% in rosin ester,respectively,and relative content of abietic type resin acids decreased from 86% to 34%.Contrast experiment without CLC showed that there were no products of dehydroabietic acid and hydrogenated resin acid in rosin ester,and relative content of abietic type resin acid did not change much.It was proved that CLC was a catalyst responsible for the disproportionation reaction of rosin.The decrease of abietic type resin acids through disproportionation was responsible for the color lightening effect on rosin ester. Related Articles | Metrics

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SYNTHESIS OF ENDO-ISOCAMPHANYL-ALKYL KETONES FROM ω-ACYLCAMPHENES BY CATALYTIC HYDROGENATION LIU Hui;XIAO Zhuan-quan;PENG Lan-hua 2002, 22 (04):  40-42.  Abstract ( 515 )   PDF (557KB) ( 634 )   Save Five endo isocamphanyl alkyl ketones were synthesized under normal pressure and room temperature by catalytic hydrogenation of an α,β-unsaturated ketone,namely ω-acylcamphene,in methanol catalysed by 5% Pd-C,with transformation rate over 95%.The products were analyzed by IR, 1H NMR, 13C NMR and MS after column chromatographic purification. Related Articles | Metrics

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EFFECT OF CELLULASE-POOR XYLANASES ON AKD-SIZING OF SECONDARY FIBERS JING Yi;YONG Qiang;YOU Ji-xue;YU Shi-yuan 2002, 22 (04):  43-46.  Abstract ( 670 )   PDF (564KB) ( 543 )   Save Cellulase poor xylanases can reduce the content of fines in the light weight coated secondary fibers and increase drainage rate under appropriate enzymolysis condition.Proportion of fines in the material is 37.5% and in Cobb value is 25.86 g/m2 by alkyl ketene dimmer(AKD) sizing.But content of fines is decreased to 28.4% and Cobb value to 20.03 g/m2 after the material has been disposed for 30 min by xylanases.Content of fines affects AKD sizing.Size resistance of paper is improved as content of fines is decreased.The higher content of fines is in the stock,the more AKD absorbed on the fines surface.AKD is easily lost into white water so that retention rate reduces.AKD sizing effect can be improved by enzymolysis of secondary fibers.Content of fines has significant effects on AKD sizing. Related Articles | Metrics

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EFFECTS OF ALTITUDES AND SEASONS ON THE FLAVONOID CONTENT OF GINKGO BILOBA LEAVES WANG Hai-feng;JU Xing-rong;HE Guang-bin;JIN Xiao-qiu;CHEN Jian 2002, 22 (04):  47-50.  Abstract ( 677 )   PDF (509KB) ( 1115 )   Save Variation rules of flavonoid content in leaves of young Ginkgo biloba tree influenced by altitudes and seasons were studied in this paper,and the affecting mechanisms of environmental factors were also discussed.Distinct variations of flavonoid content in leaves took place in the different growths period of leaves at the same position conditions.The distinctive ecological condition of higher altitude areas promoted the accumulation of flavonoids.Select of optimum time for leaf picking may improve the officinal quality of Ginkgo biloba leaves. Related Articles | Metrics

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SYNTHESIS OF DISPERSANT FOR PAPER FILLING JI Yong-xin;YANG Jie 2002, 22 (04):  51-54.  Abstract ( 621 )   PDF (726KB) ( 834 )   Save Dispersant for paper filling was synthesized.Effects of acrylic acid/maleic anhydride ratio and type of initiating agent on rasin viscosity and dispersion were discussed.Dispersant from acrylic acid/maleic anhydride molar ratio 1.5 can well disperse calcium carbonate paste,while polyacryllic acid disperses calcium carbonate paste best.Ammonium persulfate ferrous sulfite sodium bisulfite is the best initiating agent.Sodium bisulfite is 13.5% and ferrous sulfite is 0.006 7% of monomer.Optimal conditions were determined. Related Articles | Metrics

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MODIFIED MYRTAN TANNIN EXTRACT BY INTENSIVE SULFITATION AS A NEUTRALIZER FOR LEATHER CHEN Wu-yong;CHEN Fa-fen;TIAN Jin-pin 2002, 22 (04):  55-58.  Abstract ( 736 )   PDF (619KB) ( 1143 )   Save The purpose of this study is to modify tannin extract used as a neutralizer for leather.In the experiment myrtan(Myrica esculenta)tannin extract was subjected to a treatment with much more sulfite and at higher temperature compared to ordinary method.A modified product was obtained when a mixture of 100 part myrtan tannin extract,30 part NaHSO3,36 part Na2SO3 and 1 part aluminum compound was heated and reacted at 129℃ and 165 kPa for 10 h.The modified extract has pH value 7.15 at 5% solution,7.0 at 10% solution and 20%-30% tannin content by hide powder method.It has improved buffer property to maintain stable pH value between pH volute 3.5-5.5.Tanning experiment showed that it has milder astringency and tanning properties compared with ordinary extract.Modified product at 3%-5% is enough to neutralize leather thoroughly with good leather quality.In conclusion,modified myrtan tannin extract is a new material applicable as a neutralizer for leather. Related Articles | Metrics

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INTRINSIC PH VALUE OF RENEWABLE POLYMERIC MATERIALS AND IT'S CHARACTERIZATION METHOD SHEN Qing;HU Jian-feng;GU Qing-feng 2002, 22 (04):  59-62.  Abstract ( 692 )   PDF (453KB) ( 666 )   Save pH value of renewable polymeric materials is usually determined according to the method described by Browing in which the material of a fixed solid/water ratio was used.This method represents only one ratio to reflect it's pH value,which has the obvious defects of ignoring the variations of water content caused by environmental variation.In this study,Browning's method was modified by measuring a series of pH values of Pinus sylvestris L.wood of different solid/water ratios to plot curve,which exhibits good linear correlation.By extrapolating the linear line,an unique pH value was obtained which was defined as its intrinsic pH value.Finally,a comparison of intrinsic pH values of some typical renewable polymeric materials with their pH values normally obtained by traditional Browning's method has been made. Related Articles | Metrics

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STUDY ON MODIFICATION OF URUSHIOL FORMALDEHYDE CONDENSATION POLYMER WITH ANILINE CHEN Qin-hui;LIN Jin-huo 2002, 22 (04):  63-66.  Abstract ( 579 )   PDF (929KB) ( 1059 )   Save Condensation co polymer of urushiol,aniline and formaldehyde(PUFA) had been synthesized for modifying the properties of urushiol formaldehyde condensation polymer(PUF).Its structure was characterized by IR,HPLC,DSC,DMTA,etc.Physico chemical properties were also investigated. Results showed that alkali resistance of the coating film of urushiol formaldehyde condensation polymer modified by aniline had increased by 10 times, while the excellent resistance to heat and other chemical media was similar to that of PUF. Related Articles | Metrics

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ANTI-TUMOR ACTIVITY OF GARDENIA JASMINOIDES EILLS POLYSACCHARIDE SHI Ruo-fu;LI Da-li;TIAN Chun-yu;WANG Guan-lin;FANG Hong-jun 2002, 22 (04):  67-70.  Abstract ( 660 )   PDF (1162KB) ( 906 )   Save Effect of Gardenia jasminoides Eills polysaccharide (GJEP) on three kinds of tumor cells were studied with three different methods respectively.Results show that GJEP has wide ranging anti tumor activity.Effect of GJEP on tumor induced by Agrobacterium tumefaciens C58 was determined with potato chips method,and the restrain ratio of 1.258 mg/mL GJEP is 68.14% ;Effect of GJEP on erythroleukemia was determined with MTT method,and no poisonous dose is 0.4 μg/mL,low poiso nous dose is 14.33 μg/mL and median lethal dose is 62.61 μg/mL.Restrain ratio of 100 μg/mL GJEP on erythroleukemia is 63.2% ;Restrain ratio of GJEP on ascites liver cancer Hca-f tumor in BALB-c mice was determined with weight tumor method,which shows that the result of ig is better than that of ip,and restrain ratio of 500 mg/(kg·day) GJEP (ig) on ascites liver cancer Hca f tumor in BALB c mice is 49%. Related Articles | Metrics

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INVESTIGATION AND STATISTIC ANALYSIS ON QUALITY OF CHINESE GUM ROSIN FROM 1995 THROUGH 2002 ZHAO Zhen-dong 2002, 22 (04):  71-74.  Abstract ( 689 )   PDF (600KB) ( 743 )   Save State on quality of Chinese gum rosin from 1995 through 2002 was investigated in detail.Data were statistically analyzed and compared with the main technical specifications required in GB/T 8145-1987.Statistical average results showed that the present state on quality of Chinese gum rosin is superior to the specification required in GB/T 8145-1987 and is still ranking international top level,if only experimental values were considered.However,quality problems such as so called "mixed rosin" should be seriously paid attention to.According to the increasing tapping pine species and various uses of gum rosin,adoptation at different standards of gum rosins for individual pine species or individual uses would be the trend to meet the quality requirements in the future. Related Articles | Metrics

综述评论

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ADVANCES IN STUDIES ON α-GLUCURONIDASE XUE Ye-min;MAO Zhong-gui;LIU Hai-li;TANG Lei;SHAO Wei-lan 2002, 22 (04):  75-79.  Abstract ( 704 )   PDF (1659KB) ( 1496 )   Save α-Glucuronidase in microbial xylanolytic enzyme system is an important one necessary for complete hydrolysis of heteroxylan hemicellulose.Its biotechnological potentials in constructing strains of recombinant genes,which can completely degrade hemicellulose,and in exploiting hemicellulases'application are being paid attentions increasingly.Advances in studies on action mechanism,activity analysis,purification and gene cloning of α-glucuronidase are emphatically described. Related Articles | Metrics

研究简报

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STUDY ON PREPARATION TECHNOLOGY OF THERMOSTABLE XYLANASE YAN Yong-liang;XIA Li-ming 2002, 22 (04):  83-86.  Abstract ( 637 )   PDF (801KB) ( 551 )   Save Preparation of xylanase by Thermoascus aurantiacus on corn cob residue was studied.Optimal fermentation parameters were:corn cob residue 4%;rotating speed 180 r/min;initial pH value of medium 4.8%;culture temperature 45℃;C/N of medium 7.1.Xylanase activity in the broth reached 900 U/mL.Optimal temperature and pH value for the xylanase reaction were 75℃ and 4.8,respectively.The enzyme preparation was thermo stable and had a good application potential. Related Articles | Metrics

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SYNTHESIS OF 1,3-BENZODIOXOLE-5-ACETIC ACID ZHOU Ling-jun;HE Quan-guo;LIU Zheng-chun;YANG Chun;HE Nong-yue 2002, 22 (04):  80-82.  Abstract ( 742 )   PDF (417KB) ( 1120 )   Save 1,3-Benzodioxole-5-acetic acid was synthesized from 1,2-benzenediol in a four step procedure.1,2-Benzenediol reacted with dichloromethane to give 1,3-benzodioxole,which was directly chloromethylated to yield 90.1% 5-chloromethyl 1,3-benzodioxole.The chloride was converted easily to 3,4-methlenedioxyphenyl acetonitrile by 80% yield under sodium cyanide nitrilation,followed by alkali hydrolysis to give 1,3-benzodioxole-5-acetic acid.Total yield was 54.2%.Gas chromatography,infrared spectra and elemental analysis were used for characterizations. Related Articles | Metrics