Table of Content

30 September 2000, Volume 20 Issue 3 Previous Issue    Next Issue

研究报告

Select

STUDY ON THE PREPARATION OF AMINO-WOODPOWDER AND ITS ADSORPTION CAPACITY WANG Ge-hui;SONG Zhan-qian 2000, 20 (3):  1-5.  Abstract ( 536 )   PDF (875KB) ( 784 )   Save A series of amino woodpowder were prepared by chemical modification of wood through alkalization, epoxidation and amination.In this paper, factors affecting epoxide value and content of-NH2 were discussed, and the modified wood was tested by FT-IR and element analysis.The adsorption capacity of these samples were also studied.The result shows that three kinds of these modified woodpowders can be used as anion exchange resin. Related Articles | Metrics

Select

ANALYSIS OF SUB AND SUPERCRITICAL DYNAMIC EXTRACTION PROCESS OF WOOD QIAN Xue-ren;LI Jian 2000, 20 (3):  6-12.  Abstract ( 635 )   PDF (958KB) ( 1047 )   Save The sub-and supercritical dynamic extraction process of larch wood with ethanol or ethanol-water in a semicontinuous extraction apparatus was analyzed by non-isothermal experimental technique.In the range from 320℃ to 360℃, thermal effect was created obviously in the reaction system.This was attributed to the thermal decomposition of wood constituents from thermal analysis of wood constituents.The sub-and supercritical extraction process model of wood was presented based on the extraction rate, product characteristics and extraction mechanism.Under 120℃, physical dissolution of the low molecular substances in wood occurred.From 120℃ to 200℃, chemical degradation of macromolecular substances in wood occurred.From 200℃ to 275℃, chemical degradation and thermal degradation of macromolecular substances in wood occurred.From 275℃ to 370℃, thermal decomposition of macromolecular substances in wood occurred.Over 370℃, further carbonization or calcination of wood and thermal decomposition of ethanol occurred. Related Articles | Metrics

Select

STUDY ON OXIDATION MECHANISM OF GUM ROSIN UNDER HEAT WU Zong-hua;CHEN Shao-ping 2000, 20 (3):  13-16.  Abstract ( 678 )   PDF (646KB) ( 948 )   Save Changes in color and carbon groups of gum rosin under heat were investigated by CIE system L*a*b* and X-ray photoelectron spectroscopy(XPS).Analysis results revealed that color of rosin was related to isomerization and oxidation of rosin.Formation of hydroxyl groups through hydrolysis of epoxy groups was one of the main routes for rosin oxidation.Formation of carbonyl groups was responsible for the discoloration of rosin under heat. Related Articles | Metrics

Select

STUDY ON ESTERIFICATION OF ROSIN CATALYZED BY RARE EARTH METAL OXIDES HAO Qiang;HA Cheng-yong 2000, 20 (3):  17-21.  Abstract ( 621 )   PDF (845KB) ( 957 )   Save Catalytic effect of rare earth metal oxides(NdnOm, SmnOm, GdnOm, LanOm)for rosin esterifications are studied, and factors affecting the reactions are discussed in detail.The esterifying process for about 2～6h at temperature 200～260℃ in the presence of catalysts(0.33%～0.83% based on the weight of the starting rosin) provide esters with increased oxidation stability and improved color.Moreover, the esterification process is relatively straight forward, requiring no additional post treatment such as neutralization, as required in the acid catalyzed process. Related Articles | Metrics

Select

MANUFACTURE OF ACTIVATED CARBON FROM BAGASSE BY MICROWAVE METHOD MENG Mian-wu;JIANG Zhi-liang 2000, 20 (3):  22-26.  Abstract ( 726 )   PDF (913KB) ( 989 )   Save The influencing factors on properties of activated carbon such as activating agent, additives, power of microwave and activating time were systematically studied by means of orthogonal test.The best technology on manufacture of activated carbon were obtained:Bagasse were infused 48 h in 15%～25% phosphoric acid, in which 2%～4% sulfuric acid and 1%～2% hydrochloric acid were added, and radiated 15～20min by microwave at 720W.The experiment showed that yield of activated carbon was 47.5%, methylene blue decoloring ability reached 15.5mL/0.1g, and drying loss was 3.1%. Related Articles | Metrics

Select

CELLULASE PRODUCTION BY SOLID-STATE FERMENTATION OF DISTILLER'S WHEAT ZHANG Li-xing;XU Rou;SHI Gui-yang;ZHANG Ke-chang 2000, 20 (3):  27-32.  Abstract ( 607 )   PDF (987KB) ( 676 )   Save Cellulase production was carried out by solid-state process with Trichoderma reesei Rut C-30 when distiller's wheat was employed.In the trays, the optimized koji temperature was as follows:before 48h koji temperature should be controlled between 27～30℃, after 48h below 35℃, and maximal FPA activity of 611U/g was achieved.When pH value increased back to 6.0～6.2, FPA activity ceased to increase or declined.Based on the investigated data pH control strategy was proposed to be carried out when pH rised back to 4.3～4.5 for the first time.Spraying of inorganic acid into substrate, such as HCl, could counteract the increase of pH during cultivation.With pH control technology, 43.7% improvement of FPA activity was estimated and the results clearly illustrated that pH control enhanced cellulase production.With koji temperature and pH control technology, FPA activity of 508U/g koji(about 2120 U/g cellulose) was obtained.The pH control technology could be carried out in large scale solid state fermentation of cellulase. Related Articles | Metrics

Select

STUDIES ON ETHANOL EXTRACTION OF STEAM EXPLODED WHEAT STRAW CHEN Hong-zhang;LI Zuo-hu 2000, 20 (3):  33-39.  Abstract ( 701 )   PDF (1024KB) ( 798 )   Save Guided by a new concept of lignocellulose fractionation, the present work was undertaken to compare ethanol extraction of steam exploded wheat straw with that of wheat straw.The delignification rate, enzymatic hydrolysis of cellulose and the paper characteristics of ethanol extracted residue were investigated.Ethanol extracted residue and ethanol extracted lignin were analysed by IR, XPS, SEM, and mechanism on ethanol extraction of steam exploded wheat straw was explored. Related Articles | Metrics

Select

INFLUENCE OF OXYGEN CONCENTRATION ON THE PRODUCTION OF PEROXIDASES BY PHANEROCHAETE CHRYSOSPORIUM KE Shi-sheng;XIA Li-ming;ZHANG Zhao-hui;CEN Pei-lin 2000, 20 (3):  40-46.  Abstract ( 608 )   PDF (1148KB) ( 933 )   Save Oxygen concentration had obvious influences on the production of peroxidases by Phanerochaete chrysosporium. Under limited carbon source culture condition, oxygen concentration in the growth period had little influence on the production of lignin peroxidase, but it had obvious influences in the second metabolism period in which peroxidases were produced.It was found that 21% O2(in air)was the optimal oxygen condition on production of peroxidases (including both lignin peroxidase and Mn-dependent peroxidase).Further increase of oxygen concentration depressed the production of peroxidases, because more extracellular protease which was harmful to peroxidases would be produced.At the optimal oxygen concentration (in air 21% O2), the maximal lignin peroxidase activity was 360U/L under limited carbon source culture condition. Related Articles | Metrics

Select

STUDIES ON SYNTHESIS OF MYRCENE BY THERMO ISOMERIZATION OF β-PINENE LUO Jin-yue;WANG Han-zhong;PENG Shu-jing 2000, 20 (3):  47-50.  Abstract ( 849 )   PDF (772KB) ( 1002 )   Save Thermo isomerization of β-pinene in stainless steel tube of φ2 mm was studied and main factors affecting the reaction were investigated.The optimum conditions for thermo isomerization were as follows:pyrolysis temperature 550℃, N2 rate 160mL/min, reaction pressure 8.0 kPa, yield 120～150mL/min.Under these conditions, the yield of myrcene amounting to 98% in the products was obtained.Content of myrcene was 80.7%. Related Articles | Metrics

Select

STUDY ON THE EFFECT OF GLUEBOND PROCESS UPON THE PORE STRUCTURE OF ACTIVATED CARBON GAO Shang-yu;IKUO Abe;ZHOU Jian-bin;ZOU Song-lin;HU Cheng-wen;LIU Qi-ming 2000, 20 (3):  60-64.  Abstract ( 610 )   PDF (657KB) ( 813 )   Save The effect of gluebond process upon the pore structure of activated carbon have been investigated by comparing the pore structure of raw activated carbon with that of the compound of adhesive and activated carbon. The results show that the pore loss rate of activated carbon in the course of gluebond is lower while the compound of adhesive and activated carbon were made from activated carbon with higher specific surface area and specific pore volume and adhesive with higher molecular weight, as well as lower pore loss rate with the smaller pore diameter in activated carbon. Related Articles | Metrics

Select

CHEMICAL MODIFICATION OF LIGNIN IN POPLAR APMP PULPS TO PREVENT-LIGHT-INDUCED YELLOWING FANG Gui-gan;CASTELLAN Alain;BERNARD De Jéso;SHEN Zhao-bang 2000, 20 (3):  51-59.  Abstract ( 648 )   PDF (997KB) ( 677 )   Save Different brightness levels of poplar APMP pulps were prepared in a pilot scale system by alkaline peroxide mechanical pulping process, Un-treated and reduced pulps(borohydride reduction)were modified by acetic anhydride under different conditions, such as in aqueous, organic solvents and gaseous phases.The brightness of pulps before and after UV-light exposure for different periods were measured on handsheets, post colour number and BSE (brightness stabilizing effect)were used to evaluate the photo stability of the treated pulps. The results show that, both gaseous and organic phase acetylations improve pulps brightness stability more or less depending on amount of acetic anhydride applied and reaction time i. e. degree of acetylation. Completely stabilized pulps were obtained by thorough acetylation.Form UV diffuse reflectance spectra, it seems that carbonyl and phenolic groups mainly contribute to the light induced yellowing of poplar APMP. Sodium borohydride/sodium bisulfite mixture treatment of pulps followed by gaseous phase acetylation on paper sheet was proposed to be one of the practical process for yellowing inhibition of bleached APMP pulps. Related Articles | Metrics

Select

STUDY ON PROPERTIES OF URUSHIOL LANTHANUM CHELATE AND ITS INFLUENCE ON PROPERTIES OF MODIFIED URUSHIOL PAINT FILM CHEN Bing;DU Yu-min 2000, 20 (3):  70-74.  Abstract ( 592 )   PDF (794KB) ( 611 )   Save The composity, solubility, IR spectra, autoignition temperature and decomposition temperature of urushiol lanthanum chelate were determined.Effects on paint film properties of urushiol formaldehyde varnish and urushiol-epoxy varnish after addition of this chelate were studied. Related Articles | Metrics

Select

STUDY ON THE CHEMICAL CONSTITUENTS OF ESSENTIAL OIL FROM CHINESE TRADITIONAL DRUG ESHU (TUBERS OF CURCUMA) TANG Min-yan;SUN Ling-feng;WANG Hong-wu 2000, 20 (3):  65-69.  Abstract ( 735 )   PDF (807KB) ( 1064 )   Save Chemical constituents of essential oil from Chinese traditional drug eshu(Tubers of Curcuma)were studied systemically by GC-MS-DS analysis.One hundred and one peaks appeared in GC spectra.Seventy one chemical constituents were determined and twenty three of them were first determined such as α-thujene, β-thujene, isoterpinene, pinocarveol, δ-guaient, etc.The essential oil was then separated and a transparent crystal was obtained by column chromatography.The crystal was identified to be a blending crystal and consisted of four antitumourous active constituents by GC-MS-DS analysis:curcumol(64%), isocurcumenol(30%), curdione(1.1%)and curcumenol (4.7%). Related Articles | Metrics

Select

PREPARATION OF XYLO OLIGOSACCHARIDES BY MULTIPLE RUN SELECTIVE ENZYMATIC HYDROLYSIS OF XYLAN ZHAO Lin-guo;YU Shi-yuan;WU Wei-zhi 2000, 20 (3):  75-79.  Abstract ( 748 )   PDF (513KB) ( 629 )   Save Composition, yield of oligosaccharides, suitable enzyme dosage and the times of reusing the unhydrolyzed xylan were studied during preparation of xylo-oligosaccharides by multiple-run selective enzymatic hydrolysis.The results indicated that xylan became more difficult to be hydrolyzed with increased times of reuse.Moreover, the composition and degree of polymerization of oligosaccharides were changed.By adopting re-hydrolysis of the residue with increased enzyme dosage and reduced hydrolytic time, high yield of xylo-oligosaccharides could be obtained along with improved transparence of supernatant liquid of enzymatic hydrolysate.Practically, it was appropriate to reuse the unhydrolyzed xylan for two or three times. Related Articles | Metrics

Select

GAS CHROMATOGRAPHIC ANALYSIS OF HIGH PURITY 1,8-CINEOLE CAO Jing 2000, 20 (3):  80-84.  Abstract ( 668 )   PDF (659KB) ( 592 )   Save In this paper, a gas chromatographic method is introduced for quantitative determination of high purity 1, 8-cineole with FID on PEG 6000. The method is convenient, rapid and accurate. The results showed that coefficient of variation and standard deviation were 0.04%and 0.042respectively. Average recovery were 101.3%. Related Articles | Metrics

Select

STUDY ON THE BIOACTIVE CHEMICAL CONSITITUENTS IN SWERTIA YUNNANENSIS ZI Ming;LO Fang;XIN Xiao-yan;ZHANG Hui-ping 2000, 20 (3):  85-87.  Abstract ( 550 )   PDF (504KB) ( 990 )   Save In this paper, compounds possessing hypoglycemic activity were isolated from Swertia yunnanensis and identified by spectroscopic methods. Related Articles | Metrics

综述评论

Select

PRINCIPAL CHARACTERISTIC OF DEVELOPMENT OF PULPING AND PAPERMAKING TECHNIQUE HONG Feng;FANG Gui-gan;SHEN Zhao-bang 2000, 20 (3):  89-94.  Abstract ( 554 )   PDF (626KB) ( 583 )   Save This paper reviewed the principal characteristic of development of pulping and papermaking technique in the world. Related Articles | Metrics