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11.
H Endo J Cuisin N Nadee J Nabhitabhata A Suyanto Y Kawamoto T Nishida J Yamada 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(9):1027-1031
Geographical variation was examined morphologically in the common tree shrew (Tupaia glis) in some Indochinese and Malayan regions. Osteometrical examination and principal component analysis elucidated the morphological differences among various populations. The populations from southern and western Thailand were distinguished morphologically from the other populations. Variation in males from south Thailand and Kuala Lumpur suggests that the Isthmus of Kra may have an influence on the variation of skull morphology. However, the Isthmus of Kra was not completely considered as a factor of geographical separation in this species, because we could not confirm the separation in skull size and shape between the localities at least in females. While, the Kanchanaburi population in western Thailand was significantly smaller than the other population in skull size, and constituted the morphologically separable group in our study. 相似文献
12.
13.
Levoglucosan, the major intermediate in cellulose pyrolysis, is stable up to around 500?°C in the gas phase. To study whether this stability is a characteristic property of levoglucosan, the gas-phase reactivity was compared with those of methyl α- and β-glucosides at 200–500?°C (residence time 1.2–2.0 s). The methyl glucosides decomposed even at 200 and 300?°C to form levoglucosan exclusively. This selective transglycosylation was explained with a concerted mechanism. Fragmentation of the glucosides forming C1–C3 carbonyl compounds started at 400?°C, a temperature lower than that of levoglucosan (500?°C). Thus, levoglucosan is a special carbohydrate that is stable in the gas phase, and the stability is explained by the steric hindrance of the bicyclic ring. Formation of the anhydrofuranose isomer and furans was negligible from the gas-phase pyrolysis of these compounds, suggesting that these are produced mainly from the molten-phase pyrolysis. These results show the roles of gas- and molten-phase reactions during carbohydrate pyrolysis, providing insights for upgrading biomass pyrolysis/gasification processes. 相似文献
14.
Lignin pyrolysis reactions 总被引:2,自引:0,他引:2
Haruo Kawamoto 《Journal of Wood Science》2017,63(2):117-132
Lignin, an aromatic constituent of woody biomass, is a potential renewable aromatic feedstock for a sustainable future carbon economy. Pyrolysis-based technologies, such as fast pyrolysis and gasification, are promising methods for converting lignin into biochemicals, biomaterials, and biofuels. A better understanding of the molecular mechanisms involved in lignin pyrolysis/gasification would guide the development of the controlled pyrolysis and gasification systems to overcome issues with low product selectivity, an intrinsic drawback of current pyrolysis-based technologies. This review article summaries the state-of-the-art research into molecular mechanisms of lignin pyrolysis and gasification. This information should also be useful for understanding the influence of high temperature heat treatments on the properties of wood. 相似文献
15.
Kabeya H Inoue K Izumi Y Morita T Imai S Maruyama S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(12):1561-1567
The purpose of this study was to assess the role of fleas for transmission of Bartonella species among wild rodents in Japan. Flea samples were collected from wild rodents and examined genetically for Bartonella infection. Bartonella DNA was detected from 16 of 40 (40.0%) flea samples. Sequence analysis demonstrated that 3 of 16 (18.8%) of the Bartonella-positive animals were infested with fleas from which the closely related Bartonella DNA sequence was detected, indicating that the fleas acquired Bartonella from the infested rodents. The DNA was detected in hemolymph, the midgut and the ovary (only in female), indicating that Bartonella might be colonized through the midgut and distributed into the body. 相似文献
16.
Hidenori Wada Supamard Panichsakpatana Makoto Kimura Yasuo Takai 《Soil Science and Plant Nutrition》2013,59(3):449-452
Abstract Recently there has been developments in the measurement of N2 fixation due mainly to the C2H2 reduction method (1). This method, however, has several disadvantages, especially for submerged soil, and the estimated amount of fixed N2 on the basis of the C2H2 reduction activity is not very reliable. The tracer 15N2 technique which gives a reliable estimation of the fixed N2 is too expensive for common use. Development of an alternative method suitable for submerged soil would therefore be desirable. The present authors expected that the measurement of the ratio N2/Ar in the soil solution might provide advantages for the estimation of the fixed N2 in submerged soil. 相似文献
17.
The relationship of readily decomposable organic matter of the paddy soil to its colloidal complexes
Togoro Harada Hidenori Hashimoto Takayuki Yoshizawa 《Soil Science and Plant Nutrition》2013,59(1):49-50
The soil nitrogen of paddy soil is found to exist in the form of organic and inorganic nitrogen. In general, the content of inorganic nitrogen is so low that it is mainly occupied by organic nitrogen. Such soil organic nitrogen is characterized by large resistance to decomposition by soil microorganisms, and so its mineralization occurs to a small extent in most cases. However, as revealed by M. Shioiri1) and T. Harada et al. 2,3), by some appropriate treatment of paddy soil, a part of soil organic nitrogen becomes decomposed by microorganisms and mineralized under flooded condition. Among various treatment, for example, are Presented the followings: (1) air-drying of soil Prior to flooding; (2) raising the soil temperature during the flooded condition; (3) raising the soil reaction (pH 9.0) by addition of weak alkali solution; (4) the addition of neutral salts such as Nafiuoride, Na-phosphate, Na-oxalate etc., which make soil humus peptizable. 相似文献
18.
Regarding paddy soil colloids as the so-called “organo-mineral colloidal complexes” of A. F. Tyulin, the authors separated the colloidal fractions after his method, and reported the characrzstics of each fraction, and content of humus and some characteristics thereof in the previous paper1). 相似文献
19.
In our previous studies, pigeonpea (Cajanus cajan L.), groundnut (Arachis hypogaea L.), and rice (Oryza sativa L.) were found to have a higher ability to take up Fe- or Al-bound phosphorus (P) than soybean (Glycine max L.) and sorghum (Sorghum bicolor L.). Phosphorus absorption characteristics like I max, K m, C min, and FeIII reduction activity of roots, and root exudates in various crops were examined with a view to analyzing the mechanisms of P uptake. Phosphorus uptake ability was largely unrelated to variations in I max, K m, C min, and FeIII reduction activity of roots. Phosphorus-solubilizing activity in anionic fractions of root exudates was detected in pigeonpea but not in rice or groundnut. Malonic acid was the major component followed by oxalic and piscidic acid. These organic acids were able to release P from FePO4 and A1PO4. The higher P uptake ability of pigeonpea in soils with low P fertility presumably depends on the secretion of such organic acids from roots. 相似文献
20.
Influence of neutral inorganic chlorides on primary and secondary char formation from cellulose 总被引:2,自引:0,他引:2
The influence of various alkali and alkaline earth metal chlorides (LiCl, NaCl, KCl, MgCl2, and CaCl2) on primary and secondary char formation from cellulose was studied at 400°C. Secondary char was formed through carbonization
of the volatile products. All chlorides increased the primary char yield while decreasing the secondary char formation, and
this situation was promoted in the order of alkaline earth Mg, Ca, alkali Li > alkali Na, K. Levoglucosan yield also decreased
along with the secondary char yield. These results indicate that the reduced formation of volatile levoglucosan was related
to the decreasing yield of secondary char. A model experiment at 250°C revealed that these chlorides, especially the two alkaline
earth metals, had catalytic action on the polymerization of levoglucosan, which serves to reduce the formation of volatile
levoglucosan. 相似文献