The effectiveness of ClO_2 bleaching as a replacement for conventional Cl_2 bleaching,which is intensively practiced in developing countries,to reduce polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in non...The effectiveness of ClO_2 bleaching as a replacement for conventional Cl_2 bleaching,which is intensively practiced in developing countries,to reduce polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in non-wood pulp and paper mills has not been field tested.The first field study was performed to investigate PCDD/F variations when ClO_2 bleaching was used as a substitute for conventional Cl_2 bleaching in a non-wood pulp and paper mill.It was found that the PCDD/F toxic equivalents(TEQs)in solid and effluent samples were approximately 1.3–14.9 times lower when ClO_2 bleaching was used instead of the conventional Cl_2 bleaching.2,3,7,8-Substituted tetrachlorinated dibenzofurans(2,3,7,8-TCDF)were the dominant contributors to total PCDD/F TEQs in samples from the investigated mill when using conventional Cl_2 bleaching.The formation amounts of 2,3,7,8-TCDF were reduced from 1.56–2.76 pg TEQ/g to 0.02–0.32 pg TEQ/g in solid samples when ClO_2 bleaching was used instead of the conventional Cl_2 bleaching.The replacement of Cl_2 with ClO_2 might decrease the chlorination reactions of dibenzofuran as potential precursors,and thus reduce the formation amounts of 2,3,7,8-TCDF.The results could provide important knowledge for suggesting the best available technique for PCDD/F reduction for non-wood pulp and paper mills in developing countries.展开更多
Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF pr...Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF preparation were： 4% of 31441 （based on oven-dry pulp）, 80℃ and 30 rain. The CPF was characterized by FT-IR, SEM and XPS. Experimental results showed that the CPF improved the retention of precipitated calcium carbonate （PCC） filler significantly. With 0.9% CPF （based on oven-dry pulp）, the retention of PCC increased from 57.53% to 72.21%. The physical properties of paper were also slightly improved. The tensile strength and burst strength of the paper with CPF were higher than those with CPAM. CPF addition had no effect on the stock drainage.展开更多
A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surf...A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surface tension gauge to investigate changes in the pulp nature related to changes in the oxygen content, the pH value and the interfacial tension. The temperature be- fore and after ultrasonic conditioning was also investigated. The results showed that ultrasonic conditioning resulted in a decrease in the oxygen content and the interracial tension and an increase in the pH value and the temperature of the pulp. The perfect index of flotation and the perfect index of desulphurization of fine coal increased by 25.19% and 18.03%, respectively, after the pulp was ultrasonically conditioned. This study shows that ultrasonic conditioning can change the pulp nature and enhance the degree of desulphurization during high-sulfur coal flotation.展开更多
In the present study,anti-radical,anti-diabetic and antimicrobial activities of different solvent extracts of Passiflora ligularis fruits were investigated.Among the various solvents,acetone extract displayed maximum ...In the present study,anti-radical,anti-diabetic and antimicrobial activities of different solvent extracts of Passiflora ligularis fruits were investigated.Among the various solvents,acetone extract displayed maximum total phenolic(640.70 mg GAE/g extract),tannin(214.30 mg GAE/g extract)and flavonoid contents(387.33 mg RE/g extract).Results of antioxidant studies revealed that the acetone extract of fruits possessed an efficient 2,2-diphenyl-1-picryl-hydrazyl(DPPH•)(IC5019.13g/mL),2,2-azinobis(3-ethylbenzothiozoline-6-sulfonic acid)(ABTS•+)(9800.94mol/L trolox equi/g extract),superoxide(78.27%)and nitric oxide(79.95%)radical scavenging activities,ferric reducing antioxidant power(43.06 mmol Fe(II)/mg extract),metal chelating(134.53 mg EDTA/g extract)ability.The acetone extract of P.ligularis fruits also exhibited significant(P<0.005)inhibition activities onα-amylase(82.56%)andα-glucosidase(75.36%)enzymes.Furthermore,the fruits of P.ligularis also demonstrated antibacterial activities against Gram(+)and Gram(−)bacteria and inhibited the fungal strains Candida albicans(14.85 mm)and Aspergillus niger(13.91 mm)in the disc diffusion method.Quantification of polyphenolics by HPLC showed the presence of ellagic acid,gallic acid,and rutin.Therefore,the results indicate that the fruit pulp of P.ligularis can serve as a potential antioxidative and antimicrobial agent in food and pharmaceutical industries.展开更多
According to the cultivating practice ofLarix olgensis pulp plantation, IRR (Internal revenue rate) and NPV (Net present value) were taken as two economic indices to study the effect of cultivation measurements on eco...According to the cultivating practice ofLarix olgensis pulp plantation, IRR (Internal revenue rate) and NPV (Net present value) were taken as two economic indices to study the effect of cultivation measurements on economic benefit ofLarix olgensis pulp forest. The results showed that the economic benefit of this type of forest is closely related to rotation and site class. Higher economic benefit could be obtained when the rotation is shorter and site class is higher. The planting density also had an obvious influence on economic benefit. On the base of assuring survival rate and conserving rate, the less the fee used in soil preparation and young growth tending is, the higher the economic benefit is. The influence of determined six cultivation measures on economic benefit in sequence was the rotation—site class—density—management fee level—young growth tending intensity—soil preparation methods.展开更多
New methods for both the treatment of pulp waste liquor called black liquor （BL） and the recovery of chemicals by using plasma, and the concentration of BL with the freezing technique were developed. The new methods...New methods for both the treatment of pulp waste liquor called black liquor （BL） and the recovery of chemicals by using plasma, and the concentration of BL with the freezing technique were developed. The new methods aiming at the pilot plant scale are described and the experiments in a small-scale research facility for demonstration and test are presented. The energy consumption for treating waste liquid is 1 kg/kWh. Plasma processing can reduce the costs for treatment and eliminate pollution.展开更多
5, 10, 15, and 20 year old Larix gmelini and Betula platyphylla were used as pulping raw material in the research. The examination of young L. gmelini and B. Platyphyllafibrous structures showed that the fiber length ...5, 10, 15, and 20 year old Larix gmelini and Betula platyphylla were used as pulping raw material in the research. The examination of young L. gmelini and B. Platyphyllafibrous structures showed that the fiber length and ratio of length to width of 5 years old L. gmelini noticeably differed from that of mature L. gmelini. but that of 5 year old B. platyphyllawere nearby equal to that of mature B. platyphylla. The research results indicated that 15 years old B. platyphylla and 20 year old L. gmelini were best suited to pulping among the eight experimental raw materials; 10 years old B. platyphylla and 15 year old L. gmelini were optimal to the ratio of beating degree increment and corresponding beating time. The pulp characteristics of 15 year old B. platyphylla and 20 year old L. gmelini were similar to those of mature wood, and it was feasible to consider 15 years to B. platyphylla and 20 years to L. gmelini as their rotation period; 10 years and 15 years as their thinning cycles for the papermaking forest base.展开更多
The change of surface characteristics during oxygen bleaching of sulphate pulp was analysed by using ESCA. The results show that oxygen to carbon ratios gradually increase andbinding staes of carbon markedly change du...The change of surface characteristics during oxygen bleaching of sulphate pulp was analysed by using ESCA. The results show that oxygen to carbon ratios gradually increase andbinding staes of carbon markedly change during oxygen bleaching of birch sulophate pulp. ESCA is anovel and useful tool for the Study of pulp bleaching.展开更多
A method of treating pulpless coloured anterior tooth is presented.Most part ofthe coloured dentin of the labial crown was removed and the dental structure was bleachedwith 30% hydrogen peroxide for 5min.The pulp cavi...A method of treating pulpless coloured anterior tooth is presented.Most part ofthe coloured dentin of the labial crown was removed and the dental structure was bleachedwith 30% hydrogen peroxide for 5min.The pulp cavity was then filled with whitephoto-curing composite.The result of the treatment is quite satisfactory.With our treatment,the intact contour of the crown and the hardness and gloss of the enamel are preserved.SEM proved that the composite was tightly bound with the enamel of the medial wall of thepulp cavity,forming an entity with the tooth,thus guaranteeing the strength of the crown.展开更多
Bone morphogenetic protein (BMP) can promote the proliferation of dental pulp cells and induce reparative dentin formation. In this study, the inductive effect of BMP derived from bovine bone matrix on cultured human ...Bone morphogenetic protein (BMP) can promote the proliferation of dental pulp cells and induce reparative dentin formation. In this study, the inductive effect of BMP derived from bovine bone matrix on cultured human dental pulp tissue was observed under light microscope and transmission electron microscope. The results showed that. by the third day of culture, the proliferating star-shaped cells appeared with small cytoplasm and poorly-developed organelles; by the 7th day of the culture, the chondroblast-like cells with rich cytoplasm and well-developed organelles were seen embedded in hyaline matrix. This study suggests that BMP can induce dental pulp cells to differentiate from poorly differentiated state to well-differentiated state.展开更多
Effect of magnetization on oxygen concentration, pH, surface zeta potential, and wet heat of flotation pulp were researched. The result shows that magnetization treatment can improve the floatablility of coal and incr...Effect of magnetization on oxygen concentration, pH, surface zeta potential, and wet heat of flotation pulp were researched. The result shows that magnetization treatment can improve the floatablility of coal and increase the difference in wet heat among coal, refuse, and pyrite, which is favorable for slime flotation and for removing sulfur and ash from coal.展开更多
In the research Pinus koraiensis and Lorix gmelini were used as raw materials,with the analysis of L9 (34) experimental design and pulping mechanism, the optimal pulping technological parameters and corresponding AS-A...In the research Pinus koraiensis and Lorix gmelini were used as raw materials,with the analysis of L9 (34) experimental design and pulping mechanism, the optimal pulping technological parameters and corresponding AS-AQ pulp properties were obtained. The results showed that the ylelds of Pinus koraiensis and Larix gmelini AS-AQ pulp were much higher than that of corresponding kraft and has an environmental advantage over kraft. AS-AQ pulping Produces pulps with strength properties comparable to kraft.展开更多
We investigated the effects of supercritical ammonia on pulping of bamboo in a preliminary study,using testers such as differential scanning calorimetry（DSC）,scanning electron microscopy（SEM）,X-ray diffraction（XR...We investigated the effects of supercritical ammonia on pulping of bamboo in a preliminary study,using testers such as differential scanning calorimetry（DSC）,scanning electron microscopy（SEM）,X-ray diffraction（XRD） and energy dispersive spectroscopy（EDS）.The results indicate that under supercritical conditions at 185-190°C,it is possible for the ammonia to realize bamboo pulping.Compared with conventional kraft pulping,the products can meet the quality requirements of industrial paper.展开更多
Combining the characteristics of the black pulping liquor that contains a lot of lignin and other biomass resources, the technology of comprehensive waste utilization is employed. The reconstructive preparation of mod...Combining the characteristics of the black pulping liquor that contains a lot of lignin and other biomass resources, the technology of comprehensive waste utilization is employed. The reconstructive preparation of modified urea-formaldehyde glue by adding black pulping liquor and the application in extruding the medium density fibre board using this modified urea-formaldehyde glue is researched. Results show that when applying the preparation technology that alkaline reaction and then weak acid reaction, the appropriate preparation process is as follows： the adding urea process is divided into three stages （proportion 2 ： 1 ： 1） ; the pH value is 8.0, and the reaction time is 40 min in the addition reaction stage; the pH value will be naturally reduced to 3.5 -5.0, and the reaction time is 45 min in the aggregation reaction stage; the pH value is 8.0 in the urea complement stage. And the optimal condition of the reconstructive preparation the modified ureaformaldehyde glue is adding the condensed black pulping liquor after hydroxymethylation in the beginning of polycondensation reaction by 5% proportion. The application in extruding medium density fibre board with this modified urea-fosmaldehyde glue is proved feasible.展开更多
On the conditions of different ethanol concentration, acids and catalyzers, the effects of ethanol pulping on the cellulose length of bamboo were studied. The results indicates that ethanol pulping has remarkable effe...On the conditions of different ethanol concentration, acids and catalyzers, the effects of ethanol pulping on the cellulose length of bamboo were studied. The results indicates that ethanol pulping has remarkable effects on the length of cellulose, which is clearly reduced with adding ethanol and acid. The margin of length of cellulose become smaller with the increase of the catalyzer. When the ethanol concentration was 70%, the concentration of acid was 0.3% and some NaOH was used as catalyzer, the length of cellulose was the longest.展开更多
By applying ultrasound at different stage of kraft pulping process, the properties of kraft pulp produced by ultrasonic treatment were studied and compared with those by conventional method. The results indicated that...By applying ultrasound at different stage of kraft pulping process, the properties of kraft pulp produced by ultrasonic treatment were studied and compared with those by conventional method. The results indicated that, while the performances of the pulp were close to conventional kraft pulp, the chemical-to-wood ratio decreased from 20% to 17.5%, cooking time was shortened from 140 to 120 rain, and the yield increased. When the ultrasound came into play at the 90th minute during pulping process, the properties of the produced bamboo fiber were the most desirable.展开更多
基金support provided by the National 973 program (No. 2015CB453100)the Youth Innovation Promotion Association CAS (No. 2016038)the Strategic Priority Research Program of the CAS (No. XDB14020102)
文摘The effectiveness of ClO_2 bleaching as a replacement for conventional Cl_2 bleaching,which is intensively practiced in developing countries,to reduce polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in non-wood pulp and paper mills has not been field tested.The first field study was performed to investigate PCDD/F variations when ClO_2 bleaching was used as a substitute for conventional Cl_2 bleaching in a non-wood pulp and paper mill.It was found that the PCDD/F toxic equivalents(TEQs)in solid and effluent samples were approximately 1.3–14.9 times lower when ClO_2 bleaching was used instead of the conventional Cl_2 bleaching.2,3,7,8-Substituted tetrachlorinated dibenzofurans(2,3,7,8-TCDF)were the dominant contributors to total PCDD/F TEQs in samples from the investigated mill when using conventional Cl_2 bleaching.The formation amounts of 2,3,7,8-TCDF were reduced from 1.56–2.76 pg TEQ/g to 0.02–0.32 pg TEQ/g in solid samples when ClO_2 bleaching was used instead of the conventional Cl_2 bleaching.The replacement of Cl_2 with ClO_2 might decrease the chlorination reactions of dibenzofuran as potential precursors,and thus reduce the formation amounts of 2,3,7,8-TCDF.The results could provide important knowledge for suggesting the best available technique for PCDD/F reduction for non-wood pulp and paper mills in developing countries.
基金the Key Scientific and Technological Project of Heilongjiang Province (GB06B501-1)
文摘Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF preparation were： 4% of 31441 （based on oven-dry pulp）, 80℃ and 30 rain. The CPF was characterized by FT-IR, SEM and XPS. Experimental results showed that the CPF improved the retention of precipitated calcium carbonate （PCC） filler significantly. With 0.9% CPF （based on oven-dry pulp）, the retention of PCC increased from 57.53% to 72.21%. The physical properties of paper were also slightly improved. The tensile strength and burst strength of the paper with CPF were higher than those with CPAM. CPF addition had no effect on the stock drainage.
基金Projects 50274036 supported by the National Natural Science Foundation of China11531Z02 by the Educational Committee of Heilongjiang Province2009RFXXG030 by the Special Foundation of Harbin Bureau of Science and Technology
文摘A study of the effects of the pulp nature on desulphurization and de-ashing during high-sulfur coal flotation is described in this paper. Highlighted are the use of a solution oxygen gauge, a pH value gauge and a surface tension gauge to investigate changes in the pulp nature related to changes in the oxygen content, the pH value and the interfacial tension. The temperature be- fore and after ultrasonic conditioning was also investigated. The results showed that ultrasonic conditioning resulted in a decrease in the oxygen content and the interracial tension and an increase in the pH value and the temperature of the pulp. The perfect index of flotation and the perfect index of desulphurization of fine coal increased by 25.19% and 18.03%, respectively, after the pulp was ultrasonically conditioned. This study shows that ultrasonic conditioning can change the pulp nature and enhance the degree of desulphurization during high-sulfur coal flotation.
基金the financial support of this research project.(UGC letter No:F.No.37-95/2009(SR)).
文摘In the present study,anti-radical,anti-diabetic and antimicrobial activities of different solvent extracts of Passiflora ligularis fruits were investigated.Among the various solvents,acetone extract displayed maximum total phenolic(640.70 mg GAE/g extract),tannin(214.30 mg GAE/g extract)and flavonoid contents(387.33 mg RE/g extract).Results of antioxidant studies revealed that the acetone extract of fruits possessed an efficient 2,2-diphenyl-1-picryl-hydrazyl(DPPH•)(IC5019.13g/mL),2,2-azinobis(3-ethylbenzothiozoline-6-sulfonic acid)(ABTS•+)(9800.94mol/L trolox equi/g extract),superoxide(78.27%)and nitric oxide(79.95%)radical scavenging activities,ferric reducing antioxidant power(43.06 mmol Fe(II)/mg extract),metal chelating(134.53 mg EDTA/g extract)ability.The acetone extract of P.ligularis fruits also exhibited significant(P<0.005)inhibition activities onα-amylase(82.56%)andα-glucosidase(75.36%)enzymes.Furthermore,the fruits of P.ligularis also demonstrated antibacterial activities against Gram(+)and Gram(−)bacteria and inhibited the fungal strains Candida albicans(14.85 mm)and Aspergillus niger(13.91 mm)in the disc diffusion method.Quantification of polyphenolics by HPLC showed the presence of ellagic acid,gallic acid,and rutin.Therefore,the results indicate that the fruit pulp of P.ligularis can serve as a potential antioxidative and antimicrobial agent in food and pharmaceutical industries.
基金Sciences and Technology Office of Heilongjiang Province (G99B5-10).
文摘According to the cultivating practice ofLarix olgensis pulp plantation, IRR (Internal revenue rate) and NPV (Net present value) were taken as two economic indices to study the effect of cultivation measurements on economic benefit ofLarix olgensis pulp forest. The results showed that the economic benefit of this type of forest is closely related to rotation and site class. Higher economic benefit could be obtained when the rotation is shorter and site class is higher. The planting density also had an obvious influence on economic benefit. On the base of assuring survival rate and conserving rate, the less the fee used in soil preparation and young growth tending is, the higher the economic benefit is. The influence of determined six cultivation measures on economic benefit in sequence was the rotation—site class—density—management fee level—young growth tending intensity—soil preparation methods.
文摘New methods for both the treatment of pulp waste liquor called black liquor （BL） and the recovery of chemicals by using plasma, and the concentration of BL with the freezing technique were developed. The new methods aiming at the pilot plant scale are described and the experiments in a small-scale research facility for demonstration and test are presented. The energy consumption for treating waste liquid is 1 kg/kWh. Plasma processing can reduce the costs for treatment and eliminate pollution.
文摘5, 10, 15, and 20 year old Larix gmelini and Betula platyphylla were used as pulping raw material in the research. The examination of young L. gmelini and B. Platyphyllafibrous structures showed that the fiber length and ratio of length to width of 5 years old L. gmelini noticeably differed from that of mature L. gmelini. but that of 5 year old B. platyphyllawere nearby equal to that of mature B. platyphylla. The research results indicated that 15 years old B. platyphylla and 20 year old L. gmelini were best suited to pulping among the eight experimental raw materials; 10 years old B. platyphylla and 15 year old L. gmelini were optimal to the ratio of beating degree increment and corresponding beating time. The pulp characteristics of 15 year old B. platyphylla and 20 year old L. gmelini were similar to those of mature wood, and it was feasible to consider 15 years to B. platyphylla and 20 years to L. gmelini as their rotation period; 10 years and 15 years as their thinning cycles for the papermaking forest base.
文摘The change of surface characteristics during oxygen bleaching of sulphate pulp was analysed by using ESCA. The results show that oxygen to carbon ratios gradually increase andbinding staes of carbon markedly change during oxygen bleaching of birch sulophate pulp. ESCA is anovel and useful tool for the Study of pulp bleaching.
文摘A method of treating pulpless coloured anterior tooth is presented.Most part ofthe coloured dentin of the labial crown was removed and the dental structure was bleachedwith 30% hydrogen peroxide for 5min.The pulp cavity was then filled with whitephoto-curing composite.The result of the treatment is quite satisfactory.With our treatment,the intact contour of the crown and the hardness and gloss of the enamel are preserved.SEM proved that the composite was tightly bound with the enamel of the medial wall of thepulp cavity,forming an entity with the tooth,thus guaranteeing the strength of the crown.
文摘Bone morphogenetic protein (BMP) can promote the proliferation of dental pulp cells and induce reparative dentin formation. In this study, the inductive effect of BMP derived from bovine bone matrix on cultured human dental pulp tissue was observed under light microscope and transmission electron microscope. The results showed that. by the third day of culture, the proliferating star-shaped cells appeared with small cytoplasm and poorly-developed organelles; by the 7th day of the culture, the chondroblast-like cells with rich cytoplasm and well-developed organelles were seen embedded in hyaline matrix. This study suggests that BMP can induce dental pulp cells to differentiate from poorly differentiated state to well-differentiated state.
基金Naturalscience Research Programmer of Jiangsu Province High School P.R.C( 0 3 KJB44 0 13 3 ) China Postdoctoral ScienceFoundation( 2 0 0 3 0 3 3 3 3 7) +1 种基金China Coal Science F oundation( 97Process1190 7) Creative Programmer of Key UniversityTeachers
文摘Effect of magnetization on oxygen concentration, pH, surface zeta potential, and wet heat of flotation pulp were researched. The result shows that magnetization treatment can improve the floatablility of coal and increase the difference in wet heat among coal, refuse, and pyrite, which is favorable for slime flotation and for removing sulfur and ash from coal.
文摘In the research Pinus koraiensis and Lorix gmelini were used as raw materials,with the analysis of L9 (34) experimental design and pulping mechanism, the optimal pulping technological parameters and corresponding AS-AQ pulp properties were obtained. The results showed that the ylelds of Pinus koraiensis and Larix gmelini AS-AQ pulp were much higher than that of corresponding kraft and has an environmental advantage over kraft. AS-AQ pulping Produces pulps with strength properties comparable to kraft.
文摘We investigated the effects of supercritical ammonia on pulping of bamboo in a preliminary study,using testers such as differential scanning calorimetry（DSC）,scanning electron microscopy（SEM）,X-ray diffraction（XRD） and energy dispersive spectroscopy（EDS）.The results indicate that under supercritical conditions at 185-190°C,it is possible for the ammonia to realize bamboo pulping.Compared with conventional kraft pulping,the products can meet the quality requirements of industrial paper.
基金Sponsored by the Ministerial Level Advanced Research Foundation(20060013)
文摘Combining the characteristics of the black pulping liquor that contains a lot of lignin and other biomass resources, the technology of comprehensive waste utilization is employed. The reconstructive preparation of modified urea-formaldehyde glue by adding black pulping liquor and the application in extruding the medium density fibre board using this modified urea-formaldehyde glue is researched. Results show that when applying the preparation technology that alkaline reaction and then weak acid reaction, the appropriate preparation process is as follows： the adding urea process is divided into three stages （proportion 2 ： 1 ： 1） ; the pH value is 8.0, and the reaction time is 40 min in the addition reaction stage; the pH value will be naturally reduced to 3.5 -5.0, and the reaction time is 45 min in the aggregation reaction stage; the pH value is 8.0 in the urea complement stage. And the optimal condition of the reconstructive preparation the modified ureaformaldehyde glue is adding the condensed black pulping liquor after hydroxymethylation in the beginning of polycondensation reaction by 5% proportion. The application in extruding medium density fibre board with this modified urea-fosmaldehyde glue is proved feasible.
基金The National High-Tech Development863 Program of China (No.2002AA322050)
文摘On the conditions of different ethanol concentration, acids and catalyzers, the effects of ethanol pulping on the cellulose length of bamboo were studied. The results indicates that ethanol pulping has remarkable effects on the length of cellulose, which is clearly reduced with adding ethanol and acid. The margin of length of cellulose become smaller with the increase of the catalyzer. When the ethanol concentration was 70%, the concentration of acid was 0.3% and some NaOH was used as catalyzer, the length of cellulose was the longest.
文摘By applying ultrasound at different stage of kraft pulping process, the properties of kraft pulp produced by ultrasonic treatment were studied and compared with those by conventional method. The results indicated that, while the performances of the pulp were close to conventional kraft pulp, the chemical-to-wood ratio decreased from 20% to 17.5%, cooking time was shortened from 140 to 120 rain, and the yield increased. When the ultrasound came into play at the 90th minute during pulping process, the properties of the produced bamboo fiber were the most desirable.
