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1.
2.
A way of determining the flexibility of wood-pulp fibres is developed, which involves i) a precise measurement of the topology
of single-fibres by using a confocal laser scanning microscope and ii) the measurement of the elastic modulus of the fibres
by using a single-fibre fatigue cell. Reported in this paper are the initial results of tests carried out on black spruce
fibres, which have been subjected to three different levels of mechanical refining energy, namely ∼1100, 2300, and 3500 kWh/t.
It is found that the fibre flexibility rises significantly between the first and second energy levels, but it does not change
to the same degree between the second and third ones. The described procedure of measuring the flexibility of fibres may be
used to establish the appropriate refiner energy necessary for the production of a specific grade of paper.
Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 42, No. 1, pp. 115–128, January–February, 2006. 相似文献
3.
Claudio Arato E. Kendall Pye Gordon Gjennestad 《Applied biochemistry and biotechnology》2005,123(1-3):871-882
Processes that produce only ethanol from lignocellulosics display poor economics. This is generally overcome by constructing
large facilities having satisfactory economies of scale, thus making financing onerous and hindering the development of suitable
technologies. Lignol Innovations has developed a biorefining technology that employs an ethanol-based organosolv step to separate
lignin, hemicellulose components, and extractives from the cellulosic fraction of woody biomass. The resultant cellulosic
fraction is highly susceptible to enzymatic hydrolysis, generating very high yields of glucose (>90% in 12–24h) with typical
enzyme loadings of 10–20 FPU (filter paper units)/g. This glucose is readily converted to ethanol, or possibly other sugar
platform chemicals, either by sequential or simultaneous saccharification and fermentation. The liquor from the organosolv
step is processed by well-established unit operations to recover lignin, furfural, xylose, acetic acid, and a lipophylic extractives
fraction. The process ethanol is recovered and recycled back to the process. The resulting recycled process water is of a
very high quality, low BOD5, and suitable for overall system process closure. Significant benefits can be attained in greenhouse gas (GHG) emission reductions,
as per the Kyoto Protocol. Revenues from the multiple products, particularly the lignin, ethanol and xylose fractions, ensure
excellent economics for the process even in plants as small as 100 mtpd (metric tonnes per day) dry woody biomass input—a
scale suitable for processing wood residues produced by a single large sawmill. 相似文献
4.
Thermal degradation of wood treated with guanidine compounds in air: Flammability study 总被引:1,自引:0,他引:1
Wood has been treated with guanidine phosphate, guanidine nitrate, guanidine carbonate and guanidine chloride to impart flame retardancy. The samples were subjected to differential thermal analysis (DTA) and thermogravimetry (TG) from ambient temperature to 800°C in air to study their thermal behaviors. From the resulting data, kinetic parameters for different stages of thermal degradation were obtained following the method of Broido. For the decomposition of wood and flame retardant wood, the activation energy was found to decrease from 116 to 54 kJ mol–1; the char yield was found to increase from 5.6 to 34.9%, LOI from 18 to 41.5, which indicated that the flame retardancy of treated wood was improved. Effects of the different compounds on the degradation and flammability of wood have also been proposed.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
5.
We optimized the hot water extraction of polysaccharides from the root of Henry wood betony (RHWPs) using a uniform test and explored their anti-tumor activities in vitro and in vivo. The optimal extraction conditions were as follows: 40 min extraction time, liquid/solid ratio 30 mL/g, 100 min soaking time, two extraction cycles, 100% ethanol concentration, and extraction temperature of 80 °C. The molecular weight distribution of RHWPs with MWs was 228,600 g/mol and 5001 g/mol. The IR spectrum further indicated that RHWPs are acidic polysaccharides containing pyranose and furan rings. The main monosaccharides found in RHWPs were mannose, ribose, l-rhamnose monohydrate, glucuronic acid, galacturonic acid, glucose, galactose, xylose, arabinose, and fucose. RHWPs inhibited the proliferation of S180 tumor cells and induced apoptosis in vitro. Oral administration of RHWPs to tumor-bearing mice significantly inhibited the growth of the S180 xenografts, accelerated apoptosis in tumor cells, and expanded the necrotic regions. Furthermore, RHWPs also markedly increased the levels of TNF-α, IFN-γ, and IL-2 in the sera of tumor-bearing mice, and activated immune cells such as lymphocytes, NK cells, and macrophages, thereby inducing tumor cell apoptosis. Taken together, RHWPs are a promising anti-tumor agent that ought to be explored further. 相似文献
6.
Xiongyu Wu Xiaohong Liu Guangce Jiang Yongcheng Lin Willy Chan L. L. P. Vrijmoed 《Chemistry of Natural Compounds》2005,41(1):27-29
A novel metabolite 1, named xyloketal G, was isolated from cultures of marine derived mangrove fungus Xylaria sp. 2508. Its structure was elucidated by analysis of spectroscopic data.__________Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 22–23, January–February, 2005. 相似文献
7.
Smetanina O. F. Kuznetzova T. A. Denisenko V. A. Pivkin M. V. Khudyakova Yu. V. Gerasimenko A. V. Popov D. Yu. Il"in S. G. Elyakov G. B. 《Russian Chemical Bulletin》2001,50(12):2463-2465
A pentacyclic tritepenoid, 3-methoxyolean-18-ene (miliacin), was isolated for the first time from the marine fungus Chaetomium olivaceum. Its structure was determined on the basis of 2D NMR spectroscopy and X-ray diffraction data. 相似文献
8.
H. G. Struppe F. Franke J. Hofmann B. Ondruschka 《Journal of chromatography. A》1996,750(1-2):239-244
In contrast to usability of Curie-point pyrolysis at 700°C directly attached to gas chromatography-mass spectrometry (GC-MS) for determination of organic wood preservatives in waste wood samples the investigation method reported here consists of thermal desorption at temperatures about 260°C in connection with GC-MS for peak identification or GC with flame ionization detection for quantitative analyses. So-called “modified closeable sampling columns” are used as batch-reactor in thermal desorption experiments. Desorbed vapours can be introduced on capillary columns without sample discrimination and without a disturbing lost of resolution. In this manner a lot of individual polycyclic aromatic hydrocarbons were determinated in waste wood samples, especially in railway sleepers. 相似文献
9.
S. V. Nochur G. R. Jacobson M. F. Roberts A. L. Demain 《Applied biochemistry and biotechnology》1992,37(1):33-41
Fungi were screened for important industrial enzymes produced from industrial chips and sawdust of laurel (Louro inamui, Ocotea cymbarum) and cedar (Cedro, Cedrella odorata). Seven hyphomycetes and one zygomycete were isolated and characterized. Two different media for testing the enzymatic activities
were used. In general, in potato dextrose (1%) medium (M-3) a preponderancy of ligninolytic over cellulolytic enzymes was
observed. In potato infusion-sawdust wood (1%) medium (M-4) the cellulolytic, xylanolytic, and lipolytic enzymes were efficiently
induced. Significant modulation of enzyme production by the carbon source was found in the extracted fungi from self-heated
industrial chips piles of cedar and laurel trees at the Amazonian region. 相似文献
10.
Ying WANG Su Juan WANG Shun Yan MO Shuai LI Yong Chun YANG Jian Gong SHI Institute of Materia Medica Chinese Academy of Medical Sciences Peking Union Medical College 《中国化学快报》2006,(4)
A new abietane diterpene 12-hydroxy-7-oxo-5, 8, 11, 13-tetraene-18, 6-abietanolide, together with a new natural sterol stigmasta-7, 22-diene-3β, 5α, 6α-triol have been isolated from the fruiting body of the fungus Phellinus igniarius. Their structures were elucidated by spectroscopic methods including 2D NMR techniques. 相似文献