为评价生防制剂木霉菌·芽孢杆菌混剂防治水稻纹枯病的田间药效,本试验于2017—2018连续2年采用大田对比试验对木霉菌·芽孢杆菌混剂的防效和增产率进行研究。2017年结果表明在水稻纹枯病发生前或初期施用木霉菌·芽孢杆菌...为评价生防制剂木霉菌·芽孢杆菌混剂防治水稻纹枯病的田间药效,本试验于2017—2018连续2年采用大田对比试验对木霉菌·芽孢杆菌混剂的防效和增产率进行研究。2017年结果表明在水稻纹枯病发生前或初期施用木霉菌·芽孢杆菌混剂2次(100 g/667 m 2),防效和增产率可达53.61%和28.9%,超过木霉菌芽孢杆菌单一菌剂的防效和增产率(47.8%和12.5%;32.2%和26.2%)且持效期性较好。2018年结果表明,在水稻纹枯病发生前或发生初期施用木霉菌·芽孢杆菌混剂2次(200 g/667 m 2;300 g/667 m 2),防效和增产率分别达到68.52%和8.08%;79.23%和12.8%,增产显著,且对水稻安全无药害,值得进一步研究和推广应用。该研究结果将为减少化学农药的使用量,提高绿色防控水稻纹枯病的水平提供技术支撑。展开更多
This study was conducted in Xinkou Experimental Forestry Farm of Fujian Agricultural and Forestry University, Sanming, Fujian Province in January 1999. Taking pure stand of Chinese fir as control, the authors measured...This study was conducted in Xinkou Experimental Forestry Farm of Fujian Agricultural and Forestry University, Sanming, Fujian Province in January 1999. Taking pure stand of Chinese fir as control, the authors measured and studied the content of organic carbon, content of humic acid (HA), ratio of HA to fulvic acid (FA), and the characteristics of infrared light spectrum and visible light spectrum of soil humus in the mixed forest of Chinese fir and Tsoong?tree. Compared to humus composition in the pure stand of Chinese fir, the content of soil organic C, HA content, and the E4 value of HA for different layers of soil, except for the ratio of HA to FA, showed a significant increase in the mixed forest, while the ratios of E4 to E6 had a little decrease. The infrared light spectrum of humic acid had an absorptive peak at 1650 cm-1. It is concluded that the levels of humification and aromaticity of soil humus are higher in the mixed forest, which is favorable for the improvement of soil structure and nutrient supply, thus improving the soil fertility to a certain degree.展开更多
From September 1999 to July 2000, N and P concentrations of fine roots were measured with the method of sequential soil core at bimonthly intervals in a mixed forest of Tsoong's tree (Tsoongiodendron odorum Chun) ...From September 1999 to July 2000, N and P concentrations of fine roots were measured with the method of sequential soil core at bimonthly intervals in a mixed forest of Tsoong's tree (Tsoongiodendron odorum Chun) and Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) in Sanming, Fujian. The results showed that N, P concentration of Chinese fir and Tsoong's tree in fine roots were negatively related to root diameter size. The concentrations of N and P in living roots and dead roots were compared. The order of N concentration in fine roots in different samples was Tsoong's tree>undergrowth>Chinese fir, while that of P was undergrowth>Tsoong's tree>Chinese fir. For Chinese fir, the seasonal change of N, P concentrations in fine roots with various diameter classes showed a single-apex curve with a maximum in September. For Tsoong's tree, maximized concentration of N in fine roots appeared in July or September and maximized P concentration in May.展开更多
An investigation and on 13 year old (1984~1996) Chinese fir and Tsoong's tree mixed forests in Jianou City, Fujian Province, China was carried out to compare the influences of different interplanting types of i...An investigation and on 13 year old (1984~1996) Chinese fir and Tsoong's tree mixed forests in Jianou City, Fujian Province, China was carried out to compare the influences of different interplanting types of individual tree tree, row row, row strip (three rows) and pure Chinese fir stands on soil properties. Compared with the pure stands of Chinese fir, the mixed stands exerted a positive effect on soil fertility, with increases in soil organic matter, total N, available P and available K. Moreover, improvements were also observed in soil enzymatic activities, aggregate structure, structure stability, status of soil porosity, soil aeration and penetrability in mixed stands. The row row interplanted stands had the best effect on tree growth and soil properties among these mixed forests. In the southern subtropical region, the spreading of the row row mixing model of the two tree species would be helpful to preventing the soil from fertility deterioration caused by successive plantation of Chinese fir.展开更多
To study load transfer mechanism and bearing capacity of a mixed pile with stiffness core (MPSC), which is formed by inserting a precast reinforced concrete pile (PRCP), in-situ tests involving MPSCs with differen...To study load transfer mechanism and bearing capacity of a mixed pile with stiffness core (MPSC), which is formed by inserting a precast reinforced concrete pile (PRCP), in-situ tests involving MPSCs with different lengths, diameters, water cement ratios and PRCPs, cement mixed piles, and drilling hole piles, were carried out. Limit bearing capacities, load-settlement curves and stress distribution of MPSCs and mixed piles were obtained. The load transfer between cement soil and PRCP was analyzed by finite element method (FEM). Test results and FEM analysis show that an MPSC has fully utilized the big friction from a cement mixed pile and the high compressive strength from a PRCP which transfers outer top load into the inner cement soil, and that inserting a PRCP into a mixed pile changes the stress distribution of a mixed pile and improves frictional resistance between a mixed pile and soil. The length and the section area on PRCP of an MPSC both have an optimum value. Adopting MPSC is effective in improving the bearing capacity of soft soil ground.展开更多
Natural seedling regeneration and tree establishment are affected by various environmental factors. In this study, we established eight, eight, six, and four independent forest stands (each stand was further divided ...Natural seedling regeneration and tree establishment are affected by various environmental factors. In this study, we established eight, eight, six, and four independent forest stands (each stand was further divided into five subplots) respectively based on the altitudinal gradient, stand density, slope location, and slope aspect to investigate the effects of environmental factors on tree seedling regeneration in a pine-oak mixed forest. The results indicated that the seedling density was significantly higher at altitudes of 1,283 m to 1,665 m, whereas the sapling density did not differ with altitudes. The seedling and sapling density decreased significantly at 1,835 m. The seedling densities on the upper slopes were much higher than those on the middle and lower slopes, whereas the sapling density had no difference. The sapling density decreased southwest (20°-75°) whereas gradually from the it increased on the shady slopes to the northeast (40°). The seedling density increased from southwest (20°) to northeast (40°The seedling and sapling densities increased with the stand density (850 trees ha-1 to 1,525 trees ha-1) whereas the sapling density was significantly lower in stands (1,9oo trees ha-O. Principal components analysis showed that the slope aspect and stand density had more important roles in tree regeneration in this study region compared with the other two factors. Therefore, our findings suggest that it will be beneficial to keep stands at a moderate density on shady slopes. Appropriate thinning of higher density stands is also expected to promote the natural regeneration of pine-oak mixed forest.展开更多
The replacement of maize with dried cassava peel and dried caged layers' manure mixed in ratio 5:1 (w/w), ensiled for 14 days was investigated in broiler starter diet to evaluate their growth responses. The fermen...The replacement of maize with dried cassava peel and dried caged layers' manure mixed in ratio 5:1 (w/w), ensiled for 14 days was investigated in broiler starter diet to evaluate their growth responses. The fermented mixture was used to partially replace maize at 0, 25% and 50% in broiler starter diet. Ninety (90) day old chicks, of Anark breed were divided into three groups of three replicates each. There were ten birds per replicate and each group was fed each of the dietary treatment ad libitum for 28 days. Feed intake, body weight gain, feed conversion ratio (FCR), protein efficiency ratio (PER), total protein, albumin, globulin, aspartate aminotransaminase (EC 2.6.1.1.1), alanine aminotransaminase (EC 2.6.1.1.2), carcass cut parts and cost per kilogram flesh gained were monitored. Results showed linear increase (P 〈 0.05) in feed intake, body weight gain, FCR, and PER. The serum proteins and enzymes monitored were not influenced (P 〉 0.05) by treatments. The eviscerated weight, wings and large intestine length were higher (P 〈 0.05) in birds fed 50% replacement of maize diet. The cost of feed per kilogramme and cost per kilogramme flesh gained was best (P 〈 0.05) in birds fed diets 50% replacement of maize. Therefore, fermented mixture of cassava peel and caged layers' manure (FCPCLM) in broiler starter diet at 50% dietary level support good performance, enhanced gain in eviscerated weight and reasonable cost per kilogramme flesh gained at the starter phase.展开更多
This review provides an insight and up-to-date information on the application of Moringa oleifera seeds, the short falls of existing technologies as a coagulant and disinfectant in domestic water treatment. While the ...This review provides an insight and up-to-date information on the application of Moringa oleifera seeds, the short falls of existing technologies as a coagulant and disinfectant in domestic water treatment. While the coagulant properties are well reported, the disinfectant properties are not well studied. Literatures on low cost alternative technologies such as the application of hiocoagulants and slow sand filters are extensively reported. However, there is limited work addressing the limitations of these technologies that have restricted its widespread use to solve the global soaring water crises. Slow sand filters have a very slow filtration rate that depends on the biofilm layer which takes about 17 days to form. Moringa oleifera treated water cannot last more than 48 hours without bacteria regrowth. Investigation of the best method of isolating coagulant component continues with differing opinions over the nature of its coagulant ingredient not resolved in ongoing literature. An attempt was made in this paper to highlight the advantages of a Moringa disinfectant sand filter hybrid system that can purify water. Microbiological advantages of this system in providing a 100% removal of pathogens, and engineering considerations such as water treatment within an hour residence time, faster flow rates, less clogging and backwashing could be some of the advantages ofa Moringa sand filter system. The need to focus on integrating Moringa and sand filter systems for more practical applications is recommended.展开更多
In order to identify potential wood substitutes for the production of energy by gasification, binary blends (wood/miscanthus, miscanthus/straw and wood/straw) and ternary blends (wood, miscanthus and organic residu...In order to identify potential wood substitutes for the production of energy by gasification, binary blends (wood/miscanthus, miscanthus/straw and wood/straw) and ternary blends (wood, miscanthus and organic residue) were systematic tested in a laboratory bubbling fluidized bed gasification system. The results of experiments were compared with results of wood gasification. Of the binary blends, wood and miscanthus exhibited great potential as a wood substitute in fluidized bed gasification in terms of process stability and product gas quality. Adding 10 wt. % of organic residues to form ternary blends further improved the product gas quality. Gasification of fuels blended with straw tended to agglomerate in the fluidized bed because of straw's low ash melting temperature. This can be counteracted by adding Ca(OH)2 to fuels. Nonetheless, fuels blended with straw with higher percentages of Ca(OH)2 need further study to establish the optimal additive ratio.展开更多
The production of chemicals from biomass is a very challenging process due to its diverse chemical composition. Lignin, cellulose and hemicellulose are the three main biopolymers of wood biomass, with cell walls &pla...The production of chemicals from biomass is a very challenging process due to its diverse chemical composition. Lignin, cellulose and hemicellulose are the three main biopolymers of wood biomass, with cell walls &plant origin. Lignin has been chosen for the present studies due to its range of different linkages and structures. The present work involved a computational study of the most dominant lignin dimers and their vibrational structures, based on the Density Functional Theory method. Full geometry optimization of the compartments used the StoBe code with cluster model and non-local functional (RPBE) approach. The calculations of the vibrational frequencies were performed with harmonic approximations as well as an anharmonicity fit in the Morse potential function, as implemented in the StoBe code. In the case oflignin, the calculations included three different precursors based on: coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. To represent the cellulose and hemicellulose derivatives, selected aldopentoses and aldohexoses (arabinose, xylose, glucose, galactose, and mannose) were considered. Presented here are the theoretical investigations for a variety of biomass derived compounds, to give the possibility of obtaining a theoretical VBD (Vibrations Basis Database) for experimental spectra interpretation. Such a database could be further used in the preliminary composition assessment of biomass derived substrates, which will be discussed here in more detail.展开更多
D-Glucose, L-arabinose, D-mannose, D-xylose, and cellobiose are saccharification products of lignocellulose and important carbon sources for industrial fermentation. The fermentation efficiency with each of the five s...D-Glucose, L-arabinose, D-mannose, D-xylose, and cellobiose are saccharification products of lignocellulose and important carbon sources for industrial fermentation. The fermentation efficiency with each of the five sugars and the mixture of the two most dominant sugars, D-glucose and D-xylose, was evaluated for acetone- butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum ATCC 824. The utilization efficacy of the five reducing sugars was in the order of D-glucose, L-arabinose, D-mannose, o-xylose and cellobiose, o-Xylose, the second most abundant component in lignocellulosic hydrolysate, was used in the fermentation either as sole carbon source or mixed with glucose. The results indicated that maintaining pH at 4.8, the optimal pH value for solventogenesis, could increase D-xylose consumption when it was the sole carbon source. Different media con- taining D-glucose and D-xylose at different ratios (1:2, 1:5, 1.5:1, 2:1 ) were then attempted for the ABE fermenta- tion. When pH was at 4.8 and xylose concentration was five times that of glucose, a 256.9% increase in xylose utilization and 263.7% increase in solvent production were obtained compared to those without pH control. These results demonstrate a possible approach combining optimized pH control and D-glucose and D-xylose ratio to increase the fermentation efficiency of lignocellulosic hydrolysate.展开更多
In this study, the mechanical properties (tensile strength, elongation at break and folding resistance) of edible biopolymer film blends formed from blended cassava starch and rice flour at different compositions wi...In this study, the mechanical properties (tensile strength, elongation at break and folding resistance) of edible biopolymer film blends formed from blended cassava starch and rice flour at different compositions with sorbital used as a plasticizer. A suitable ratio of cassava starch and rice flour to water at 10% w/v was used to form a film solution. The addition of a plasticizer agent up to 30% w/w of blending compositions improved the mechanical properties of the generated films. The mechanical properties of the edible blended films with 30% plasticizer were strongly dependent on the blending compositions. Our results pointed out that the cassava starch and rice flour films at a ratio of 70:30 with sorbitol 30% (w/w) had the highest tensile strength which related to folding endurance of the films.展开更多
Increases in climate variability, including extremes, may be expected with anthropogenic climate change, but some evidence is contrary. The issue is important because the consequences of variability can be critical fo...Increases in climate variability, including extremes, may be expected with anthropogenic climate change, but some evidence is contrary. The issue is important because the consequences of variability can be critical for ecosystems. It has long been known and often rehearsed that ecological consequences of increased variability may be greater than those that result from expected changes in mean temperature and precipitation. Tree rings have been useful indicators of ecological response to climate change and used as proxies for climate variability;work in the Rocky Mountains, USA, has been particularly informative. Chronologies from two high elevation species ranging over 2500 km were analyzed for changes in variance through time. These spatially extensive and disaggregated tree ring records do not show a consistent pattern of change in variance over the past 500 or 100 years; heteroscedasticity has recently been greater. A lack of consistent response in growth over a period encompassing changes in mean climate indicates that mountain environments, with inconsistent trends in temperature and precipitation,may be too complex to act as sentinels.展开更多
This paper investigated the compressive behavior of a novel glass fiber reinforced polymer(GFRP)-timber-reinforced concrete composite column(GTRC column),which consisted of reinforced concrete with an outer GFRP lamin...This paper investigated the compressive behavior of a novel glass fiber reinforced polymer(GFRP)-timber-reinforced concrete composite column(GTRC column),which consisted of reinforced concrete with an outer GFRP laminate and a paulownia timber core.The axial compression tests were performed on 13 specimens to validate the effects of various timber core diameters,slenderness ratios,and GFRP laminate layers/angles on the mechanical behaviors.Test results indicated that with the increase in the timber core diameter,the ductility and energy dissipation ability of the composite column increased by 52.6%and 21.6%,respectively,whereas the ultimate load-bearing capacity and initial stiffness showed a slight decrease.In addition,the GFRP laminate considerably improved the ultimate load-bearing capacity,stiffness,ductility and energy dissipation capability by 212.1%,26.6%,64.3%and 3820%,accordingly.Moreover,considering the influence of timber core diameter,an ultimate load-bearing capacity adjustment coefficient was proposed.Finally,a formula was established based on the force equilibrium and superposition for predicting the axial bearing capacity of the GTRC columns.展开更多
In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein. Genistein was incorporated in the mixed poloxamer micelles by thin-f...In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein. Genistein was incorporated in the mixed poloxamer micelles by thin-film hydration method, and its physicochemical properties, including particle size, zeta potential, entrapment efficiency and drug loading, were investigated. In vitro release of genistein from the mixed micelles was monitored by dialysis method, and pharmacokinetic study of genistein loaded mixed micelles was carried out in rats. We found that the particle size and zeta potential of mixed micelles were(20.31±0.43) nm and(–8.94±0.35) m V, with encapsulation efficiency 90.59%±0.67% and drug loading 7.74%±0.05%. Solubility of genistein in mixed micelles reached 3.80 mg/m L, which was about 130 times higher than that in water. Genistein-loaded mixed micelles showed sustained release characteristics in vitro with no burst release phenomenon, but it was faster than suspension. The AUC0–t and AUC0–∞ of mixed micelles were 196.74% and 204.62% greater than that of genisein suspension, respectively. Consequently, poloxamer 403/407 mixed micelles significantly improved the solubility and oral bioavailability of genistein, which could be used as an effective drug delivery system for oral administration of poorly soluble drugs.展开更多
This paper describes an experimental investigation of pyrolysis of woody biomass mixture. The mixture consists of oak, beech, fir, cherry, walnut and linden wood chips with equal mass fractions. During the experiment,...This paper describes an experimental investigation of pyrolysis of woody biomass mixture. The mixture consists of oak, beech, fir, cherry, walnut and linden wood chips with equal mass fractions. During the experiment, the sample mass inside the reactor was 10 g with a particle diameter of 5-10 mm. The sample in the reactor was heated in the temperature range of 24-650℃. Average sample heating rates in the reactor were 21, 30 and 54 ℃/min. The sample mass before, during and after pyrolysis was determined using a digital scale. Experimental results of the sample mass change indicate that the highest yield of pyrolytic gas was achieved at the temperature slightly above 650℃ and ranged from 77 to 85%, while char yield ranged from 15 to 23%. Heating rate has sig- nificant influence on the pyrolytic gas and char yields. It was determined that higher pyrolysis temperatures and heating rates induce higher yields of pyrolytic gas, while the char mass reduces. Condensation of pyrolytic gas at the end of the pyrolysis process at 650℃ produced 2.4-2.72 g of liquid phase. The results obtained represent a starting basis for determining material and heat balance of pyrolysis process as well as woody biomass pyrolysis equipment.展开更多
文摘为评价生防制剂木霉菌·芽孢杆菌混剂防治水稻纹枯病的田间药效,本试验于2017—2018连续2年采用大田对比试验对木霉菌·芽孢杆菌混剂的防效和增产率进行研究。2017年结果表明在水稻纹枯病发生前或初期施用木霉菌·芽孢杆菌混剂2次(100 g/667 m 2),防效和增产率可达53.61%和28.9%,超过木霉菌芽孢杆菌单一菌剂的防效和增产率(47.8%和12.5%;32.2%和26.2%)且持效期性较好。2018年结果表明,在水稻纹枯病发生前或发生初期施用木霉菌·芽孢杆菌混剂2次(200 g/667 m 2;300 g/667 m 2),防效和增产率分别达到68.52%和8.08%;79.23%和12.8%,增产显著,且对水稻安全无药害,值得进一步研究和推广应用。该研究结果将为减少化学农药的使用量,提高绿色防控水稻纹枯病的水平提供技术支撑。
基金Foundation item:This paper was supported by Natural Science Foundation of Fujian Province (B0110025) and Foundation for University Key Teacher by the Ministry of Education.
文摘This study was conducted in Xinkou Experimental Forestry Farm of Fujian Agricultural and Forestry University, Sanming, Fujian Province in January 1999. Taking pure stand of Chinese fir as control, the authors measured and studied the content of organic carbon, content of humic acid (HA), ratio of HA to fulvic acid (FA), and the characteristics of infrared light spectrum and visible light spectrum of soil humus in the mixed forest of Chinese fir and Tsoong?tree. Compared to humus composition in the pure stand of Chinese fir, the content of soil organic C, HA content, and the E4 value of HA for different layers of soil, except for the ratio of HA to FA, showed a significant increase in the mixed forest, while the ratios of E4 to E6 had a little decrease. The infrared light spectrum of humic acid had an absorptive peak at 1650 cm-1. It is concluded that the levels of humification and aromaticity of soil humus are higher in the mixed forest, which is favorable for the improvement of soil structure and nutrient supply, thus improving the soil fertility to a certain degree.
基金The Foundation of Post-doctoral Research of China (1999, No 10), the Foundation for University Key Teacher by the Ministry of Ed
文摘From September 1999 to July 2000, N and P concentrations of fine roots were measured with the method of sequential soil core at bimonthly intervals in a mixed forest of Tsoong's tree (Tsoongiodendron odorum Chun) and Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) in Sanming, Fujian. The results showed that N, P concentration of Chinese fir and Tsoong's tree in fine roots were negatively related to root diameter size. The concentrations of N and P in living roots and dead roots were compared. The order of N concentration in fine roots in different samples was Tsoong's tree>undergrowth>Chinese fir, while that of P was undergrowth>Tsoong's tree>Chinese fir. For Chinese fir, the seasonal change of N, P concentrations in fine roots with various diameter classes showed a single-apex curve with a maximum in September. For Tsoong's tree, maximized concentration of N in fine roots appeared in July or September and maximized P concentration in May.
文摘An investigation and on 13 year old (1984~1996) Chinese fir and Tsoong's tree mixed forests in Jianou City, Fujian Province, China was carried out to compare the influences of different interplanting types of individual tree tree, row row, row strip (three rows) and pure Chinese fir stands on soil properties. Compared with the pure stands of Chinese fir, the mixed stands exerted a positive effect on soil fertility, with increases in soil organic matter, total N, available P and available K. Moreover, improvements were also observed in soil enzymatic activities, aggregate structure, structure stability, status of soil porosity, soil aeration and penetrability in mixed stands. The row row interplanted stands had the best effect on tree growth and soil properties among these mixed forests. In the southern subtropical region, the spreading of the row row mixing model of the two tree species would be helpful to preventing the soil from fertility deterioration caused by successive plantation of Chinese fir.
基金Supported by National Natural Science Foundation of China( No. 59978028).
文摘To study load transfer mechanism and bearing capacity of a mixed pile with stiffness core (MPSC), which is formed by inserting a precast reinforced concrete pile (PRCP), in-situ tests involving MPSCs with different lengths, diameters, water cement ratios and PRCPs, cement mixed piles, and drilling hole piles, were carried out. Limit bearing capacities, load-settlement curves and stress distribution of MPSCs and mixed piles were obtained. The load transfer between cement soil and PRCP was analyzed by finite element method (FEM). Test results and FEM analysis show that an MPSC has fully utilized the big friction from a cement mixed pile and the high compressive strength from a PRCP which transfers outer top load into the inner cement soil, and that inserting a PRCP into a mixed pile changes the stress distribution of a mixed pile and improves frictional resistance between a mixed pile and soil. The length and the section area on PRCP of an MPSC both have an optimum value. Adopting MPSC is effective in improving the bearing capacity of soft soil ground.
基金funded by the Special Research Program for Public-Welfare Forestry of State Forestry Administration of China (Grant No. 20100400206)National Natural Science Funds of China (Grant No. 31070570)CFERN & GENE Award Funds on Ecological Paper
文摘Natural seedling regeneration and tree establishment are affected by various environmental factors. In this study, we established eight, eight, six, and four independent forest stands (each stand was further divided into five subplots) respectively based on the altitudinal gradient, stand density, slope location, and slope aspect to investigate the effects of environmental factors on tree seedling regeneration in a pine-oak mixed forest. The results indicated that the seedling density was significantly higher at altitudes of 1,283 m to 1,665 m, whereas the sapling density did not differ with altitudes. The seedling and sapling density decreased significantly at 1,835 m. The seedling densities on the upper slopes were much higher than those on the middle and lower slopes, whereas the sapling density had no difference. The sapling density decreased southwest (20°-75°) whereas gradually from the it increased on the shady slopes to the northeast (40°). The seedling density increased from southwest (20°) to northeast (40°The seedling and sapling densities increased with the stand density (850 trees ha-1 to 1,525 trees ha-1) whereas the sapling density was significantly lower in stands (1,9oo trees ha-O. Principal components analysis showed that the slope aspect and stand density had more important roles in tree regeneration in this study region compared with the other two factors. Therefore, our findings suggest that it will be beneficial to keep stands at a moderate density on shady slopes. Appropriate thinning of higher density stands is also expected to promote the natural regeneration of pine-oak mixed forest.
文摘The replacement of maize with dried cassava peel and dried caged layers' manure mixed in ratio 5:1 (w/w), ensiled for 14 days was investigated in broiler starter diet to evaluate their growth responses. The fermented mixture was used to partially replace maize at 0, 25% and 50% in broiler starter diet. Ninety (90) day old chicks, of Anark breed were divided into three groups of three replicates each. There were ten birds per replicate and each group was fed each of the dietary treatment ad libitum for 28 days. Feed intake, body weight gain, feed conversion ratio (FCR), protein efficiency ratio (PER), total protein, albumin, globulin, aspartate aminotransaminase (EC 2.6.1.1.1), alanine aminotransaminase (EC 2.6.1.1.2), carcass cut parts and cost per kilogram flesh gained were monitored. Results showed linear increase (P 〈 0.05) in feed intake, body weight gain, FCR, and PER. The serum proteins and enzymes monitored were not influenced (P 〉 0.05) by treatments. The eviscerated weight, wings and large intestine length were higher (P 〈 0.05) in birds fed 50% replacement of maize diet. The cost of feed per kilogramme and cost per kilogramme flesh gained was best (P 〈 0.05) in birds fed diets 50% replacement of maize. Therefore, fermented mixture of cassava peel and caged layers' manure (FCPCLM) in broiler starter diet at 50% dietary level support good performance, enhanced gain in eviscerated weight and reasonable cost per kilogramme flesh gained at the starter phase.
文摘This review provides an insight and up-to-date information on the application of Moringa oleifera seeds, the short falls of existing technologies as a coagulant and disinfectant in domestic water treatment. While the coagulant properties are well reported, the disinfectant properties are not well studied. Literatures on low cost alternative technologies such as the application of hiocoagulants and slow sand filters are extensively reported. However, there is limited work addressing the limitations of these technologies that have restricted its widespread use to solve the global soaring water crises. Slow sand filters have a very slow filtration rate that depends on the biofilm layer which takes about 17 days to form. Moringa oleifera treated water cannot last more than 48 hours without bacteria regrowth. Investigation of the best method of isolating coagulant component continues with differing opinions over the nature of its coagulant ingredient not resolved in ongoing literature. An attempt was made in this paper to highlight the advantages of a Moringa disinfectant sand filter hybrid system that can purify water. Microbiological advantages of this system in providing a 100% removal of pathogens, and engineering considerations such as water treatment within an hour residence time, faster flow rates, less clogging and backwashing could be some of the advantages ofa Moringa sand filter system. The need to focus on integrating Moringa and sand filter systems for more practical applications is recommended.
文摘In order to identify potential wood substitutes for the production of energy by gasification, binary blends (wood/miscanthus, miscanthus/straw and wood/straw) and ternary blends (wood, miscanthus and organic residue) were systematic tested in a laboratory bubbling fluidized bed gasification system. The results of experiments were compared with results of wood gasification. Of the binary blends, wood and miscanthus exhibited great potential as a wood substitute in fluidized bed gasification in terms of process stability and product gas quality. Adding 10 wt. % of organic residues to form ternary blends further improved the product gas quality. Gasification of fuels blended with straw tended to agglomerate in the fluidized bed because of straw's low ash melting temperature. This can be counteracted by adding Ca(OH)2 to fuels. Nonetheless, fuels blended with straw with higher percentages of Ca(OH)2 need further study to establish the optimal additive ratio.
文摘The production of chemicals from biomass is a very challenging process due to its diverse chemical composition. Lignin, cellulose and hemicellulose are the three main biopolymers of wood biomass, with cell walls &plant origin. Lignin has been chosen for the present studies due to its range of different linkages and structures. The present work involved a computational study of the most dominant lignin dimers and their vibrational structures, based on the Density Functional Theory method. Full geometry optimization of the compartments used the StoBe code with cluster model and non-local functional (RPBE) approach. The calculations of the vibrational frequencies were performed with harmonic approximations as well as an anharmonicity fit in the Morse potential function, as implemented in the StoBe code. In the case oflignin, the calculations included three different precursors based on: coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. To represent the cellulose and hemicellulose derivatives, selected aldopentoses and aldohexoses (arabinose, xylose, glucose, galactose, and mannose) were considered. Presented here are the theoretical investigations for a variety of biomass derived compounds, to give the possibility of obtaining a theoretical VBD (Vibrations Basis Database) for experimental spectra interpretation. Such a database could be further used in the preliminary composition assessment of biomass derived substrates, which will be discussed here in more detail.
基金Supported by the National Natural Science Foundation of China(20306026 and 21376215)the National High Technology Research and Development Program of China(2012AA022302)
文摘D-Glucose, L-arabinose, D-mannose, D-xylose, and cellobiose are saccharification products of lignocellulose and important carbon sources for industrial fermentation. The fermentation efficiency with each of the five sugars and the mixture of the two most dominant sugars, D-glucose and D-xylose, was evaluated for acetone- butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum ATCC 824. The utilization efficacy of the five reducing sugars was in the order of D-glucose, L-arabinose, D-mannose, o-xylose and cellobiose, o-Xylose, the second most abundant component in lignocellulosic hydrolysate, was used in the fermentation either as sole carbon source or mixed with glucose. The results indicated that maintaining pH at 4.8, the optimal pH value for solventogenesis, could increase D-xylose consumption when it was the sole carbon source. Different media con- taining D-glucose and D-xylose at different ratios (1:2, 1:5, 1.5:1, 2:1 ) were then attempted for the ABE fermenta- tion. When pH was at 4.8 and xylose concentration was five times that of glucose, a 256.9% increase in xylose utilization and 263.7% increase in solvent production were obtained compared to those without pH control. These results demonstrate a possible approach combining optimized pH control and D-glucose and D-xylose ratio to increase the fermentation efficiency of lignocellulosic hydrolysate.
文摘In this study, the mechanical properties (tensile strength, elongation at break and folding resistance) of edible biopolymer film blends formed from blended cassava starch and rice flour at different compositions with sorbital used as a plasticizer. A suitable ratio of cassava starch and rice flour to water at 10% w/v was used to form a film solution. The addition of a plasticizer agent up to 30% w/w of blending compositions improved the mechanical properties of the generated films. The mechanical properties of the edible blended films with 30% plasticizer were strongly dependent on the blending compositions. Our results pointed out that the cassava starch and rice flour films at a ratio of 70:30 with sorbitol 30% (w/w) had the highest tensile strength which related to folding endurance of the films.
文摘Increases in climate variability, including extremes, may be expected with anthropogenic climate change, but some evidence is contrary. The issue is important because the consequences of variability can be critical for ecosystems. It has long been known and often rehearsed that ecological consequences of increased variability may be greater than those that result from expected changes in mean temperature and precipitation. Tree rings have been useful indicators of ecological response to climate change and used as proxies for climate variability;work in the Rocky Mountains, USA, has been particularly informative. Chronologies from two high elevation species ranging over 2500 km were analyzed for changes in variance through time. These spatially extensive and disaggregated tree ring records do not show a consistent pattern of change in variance over the past 500 or 100 years; heteroscedasticity has recently been greater. A lack of consistent response in growth over a period encompassing changes in mean climate indicates that mountain environments, with inconsistent trends in temperature and precipitation,may be too complex to act as sentinels.
基金supported by the Program of the China Postdoctoral Science Foundation(Grant No.2021M690264 and 2021T140031)the Youth Talent Cultivation Program of Jiangsu University,and the State Key Laboratory of Special Functional Waterproof Materials(No.SKWL-2021KF10).
文摘This paper investigated the compressive behavior of a novel glass fiber reinforced polymer(GFRP)-timber-reinforced concrete composite column(GTRC column),which consisted of reinforced concrete with an outer GFRP laminate and a paulownia timber core.The axial compression tests were performed on 13 specimens to validate the effects of various timber core diameters,slenderness ratios,and GFRP laminate layers/angles on the mechanical behaviors.Test results indicated that with the increase in the timber core diameter,the ductility and energy dissipation ability of the composite column increased by 52.6%and 21.6%,respectively,whereas the ultimate load-bearing capacity and initial stiffness showed a slight decrease.In addition,the GFRP laminate considerably improved the ultimate load-bearing capacity,stiffness,ductility and energy dissipation capability by 212.1%,26.6%,64.3%and 3820%,accordingly.Moreover,considering the influence of timber core diameter,an ultimate load-bearing capacity adjustment coefficient was proposed.Finally,a formula was established based on the force equilibrium and superposition for predicting the axial bearing capacity of the GTRC columns.
基金The Zhejiang Public Welfare Technology Application Research Project(Grant No.2015C31100)the Ningbo Science and Technology Innovation Team Project(Grant No.2015C110027)
文摘In the present study, we aimed to prepare poloxamer 403/407 mixed micelles in order to improve the solubility and oral bioavailability of genistein. Genistein was incorporated in the mixed poloxamer micelles by thin-film hydration method, and its physicochemical properties, including particle size, zeta potential, entrapment efficiency and drug loading, were investigated. In vitro release of genistein from the mixed micelles was monitored by dialysis method, and pharmacokinetic study of genistein loaded mixed micelles was carried out in rats. We found that the particle size and zeta potential of mixed micelles were(20.31±0.43) nm and(–8.94±0.35) m V, with encapsulation efficiency 90.59%±0.67% and drug loading 7.74%±0.05%. Solubility of genistein in mixed micelles reached 3.80 mg/m L, which was about 130 times higher than that in water. Genistein-loaded mixed micelles showed sustained release characteristics in vitro with no burst release phenomenon, but it was faster than suspension. The AUC0–t and AUC0–∞ of mixed micelles were 196.74% and 204.62% greater than that of genisein suspension, respectively. Consequently, poloxamer 403/407 mixed micelles significantly improved the solubility and oral bioavailability of genistein, which could be used as an effective drug delivery system for oral administration of poorly soluble drugs.
基金Partially financed by the Ministry of Education,Science and Technological Development of the Republic of Serbia
文摘This paper describes an experimental investigation of pyrolysis of woody biomass mixture. The mixture consists of oak, beech, fir, cherry, walnut and linden wood chips with equal mass fractions. During the experiment, the sample mass inside the reactor was 10 g with a particle diameter of 5-10 mm. The sample in the reactor was heated in the temperature range of 24-650℃. Average sample heating rates in the reactor were 21, 30 and 54 ℃/min. The sample mass before, during and after pyrolysis was determined using a digital scale. Experimental results of the sample mass change indicate that the highest yield of pyrolytic gas was achieved at the temperature slightly above 650℃ and ranged from 77 to 85%, while char yield ranged from 15 to 23%. Heating rate has sig- nificant influence on the pyrolytic gas and char yields. It was determined that higher pyrolysis temperatures and heating rates induce higher yields of pyrolytic gas, while the char mass reduces. Condensation of pyrolytic gas at the end of the pyrolysis process at 650℃ produced 2.4-2.72 g of liquid phase. The results obtained represent a starting basis for determining material and heat balance of pyrolysis process as well as woody biomass pyrolysis equipment.