The heartwood of teak in certain areas of Java Island displays irregular black streaks along the annual rings. We investigated the color and chemical characteristics in a radial direction of partially black-streaked h...The heartwood of teak in certain areas of Java Island displays irregular black streaks along the annual rings. We investigated the color and chemical characteristics in a radial direction of partially black-streaked heartwood samples. Color properties （pH value, inorganic element, extractive content and extractive characterization） were measured in the color co-ordinates CIELAB system. The results show that the black streak part was 12-15 brightness （L^＊） value units less than the normal heartwood. Furthermore, the black streak part had more red （a^＊） but less yellow （b^＊）, hue （h） and chroma （C^＊） than the normal wood. The pH value, ash content and calcium contents of the black streak part were slightly higher than those obtained for the normal wood. The content of the low-polar extractive （n-hexane and ethyl acetate） of the black streak part was considerably higher than that for the normal wood. The blackening process was speculated to be a kind of defense mechanism indicated by remarkable amount ofbioactive compound called tectoquinone.展开更多
With the development of web 2.0, more and more social community applications appeared. The classical type of this kind of application is blog and facebook. The most important feature of these applications is that it i...With the development of web 2.0, more and more social community applications appeared. The classical type of this kind of application is blog and facebook. The most important feature of these applications is that it is a self-media and users can post their own ideas in Internet. By using these social community applications, a big social network is formed. To study the feature of social network, it is important to mine the individual information at the beginning. In this paper, we propose a User Role based method to mine the relation between the user and object thing. First, we extract the User Role from the semantic dictionary Wordnet. Then, the feature of User Role is also mined by considering the hypemymy and hyponymy relation. Finally, we can use these features to deduce the User Role. In our experiments, we use a big corpus from TREC 2006 to test the mining performance. The experiment results show that the User Role effectively explores the feature of user.展开更多
A method for the simultaneous separation and determination of organic acids and inorganic anions in Bayer liquors was developed by gradient ion chromatography with suppressed conductivity detection. Formate, acetate, ...A method for the simultaneous separation and determination of organic acids and inorganic anions in Bayer liquors was developed by gradient ion chromatography with suppressed conductivity detection. Formate, acetate, propionate, oxalate, succinate, glutarate, fluoride, chloride and sulfate were separated and determined in 33 min. The samples were pretreated with solid-phase extraction, which has high selectivity for removing a large number of metallic ions in the Bayer liquors, and filtered with a 0.45 μm filter membrane before being injected into the ion chromatographic system. The separation of six organic acids and three inorganic anions was achieved on an IonPac AS11-HC column with KOH as the eluent, and the detection was performed by a conductivity detection mode. No interference is found in the presence of fluorate, chlorate and sulphate when organic acids are determined. The calibration graphs of peak area for all the analytes are linear over a wide range. The relative standard derivation of the peak area of analytes is less than 2.14%. Under optimum conditions the detection ranges from 0.2 to 100.0 mg/L. The average recoveries of the added standards are between 94.3% and 102.8%.展开更多
Taking advantage of the effects on DNA secondary structure of two DNA-intercalators,ethidium bromide and chloroquine,we used each of them to treat nuclei from both mature erythrocytes and reticulocytes of chicken,as a...Taking advantage of the effects on DNA secondary structure of two DNA-intercalators,ethidium bromide and chloroquine,we used each of them to treat nuclei from both mature erythrocytes and reticulocytes of chicken,as an alternative approach to study the relationships between DNA secondary structure,nuclear proteins and chromatin structure.We presented results of differential extraction of nuclear proteins from nuclei with DNA-intercalators,as well as preliminary characterization of these proteins.A 45kd protein is the major component in fractions extracted by both intercalators from nuclei from either mature erythrocytes or reticulocytes and seems to be a DNA-binding protein.Furthermore,from current concepts of functional aspects of DNA conformation and structural heterogeneity in chromatin and nuclear proteins,we have discussed both the significance of our results as well as technical aspects of this approach.展开更多
基金supported by the Ministry of Educa-tion, Culture, Sports, Science and Technology in Japan.
文摘The heartwood of teak in certain areas of Java Island displays irregular black streaks along the annual rings. We investigated the color and chemical characteristics in a radial direction of partially black-streaked heartwood samples. Color properties （pH value, inorganic element, extractive content and extractive characterization） were measured in the color co-ordinates CIELAB system. The results show that the black streak part was 12-15 brightness （L^＊） value units less than the normal heartwood. Furthermore, the black streak part had more red （a^＊） but less yellow （b^＊）, hue （h） and chroma （C^＊） than the normal wood. The pH value, ash content and calcium contents of the black streak part were slightly higher than those obtained for the normal wood. The content of the low-polar extractive （n-hexane and ethyl acetate） of the black streak part was considerably higher than that for the normal wood. The blackening process was speculated to be a kind of defense mechanism indicated by remarkable amount ofbioactive compound called tectoquinone.
基金National Natural Science Foundations of China (No.60873179, No.60803078)Shenzhen Municipal Science and Technology Planning Program for Basic Research, China ( No. JC200903180630A)+1 种基金Research Fund for the Doctoral Program of Higher Education of China (No.20090121110032)Technology Research Program of Fujian Province of China (No.2006H0037)
文摘With the development of web 2.0, more and more social community applications appeared. The classical type of this kind of application is blog and facebook. The most important feature of these applications is that it is a self-media and users can post their own ideas in Internet. By using these social community applications, a big social network is formed. To study the feature of social network, it is important to mine the individual information at the beginning. In this paper, we propose a User Role based method to mine the relation between the user and object thing. First, we extract the User Role from the semantic dictionary Wordnet. Then, the feature of User Role is also mined by considering the hypemymy and hyponymy relation. Finally, we can use these features to deduce the User Role. In our experiments, we use a big corpus from TREC 2006 to test the mining performance. The experiment results show that the User Role effectively explores the feature of user.
基金Project(2005CB623702) supported by the National Key Basic Research Program of China
文摘A method for the simultaneous separation and determination of organic acids and inorganic anions in Bayer liquors was developed by gradient ion chromatography with suppressed conductivity detection. Formate, acetate, propionate, oxalate, succinate, glutarate, fluoride, chloride and sulfate were separated and determined in 33 min. The samples were pretreated with solid-phase extraction, which has high selectivity for removing a large number of metallic ions in the Bayer liquors, and filtered with a 0.45 μm filter membrane before being injected into the ion chromatographic system. The separation of six organic acids and three inorganic anions was achieved on an IonPac AS11-HC column with KOH as the eluent, and the detection was performed by a conductivity detection mode. No interference is found in the presence of fluorate, chlorate and sulphate when organic acids are determined. The calibration graphs of peak area for all the analytes are linear over a wide range. The relative standard derivation of the peak area of analytes is less than 2.14%. Under optimum conditions the detection ranges from 0.2 to 100.0 mg/L. The average recoveries of the added standards are between 94.3% and 102.8%.
文摘Taking advantage of the effects on DNA secondary structure of two DNA-intercalators,ethidium bromide and chloroquine,we used each of them to treat nuclei from both mature erythrocytes and reticulocytes of chicken,as an alternative approach to study the relationships between DNA secondary structure,nuclear proteins and chromatin structure.We presented results of differential extraction of nuclear proteins from nuclei with DNA-intercalators,as well as preliminary characterization of these proteins.A 45kd protein is the major component in fractions extracted by both intercalators from nuclei from either mature erythrocytes or reticulocytes and seems to be a DNA-binding protein.Furthermore,from current concepts of functional aspects of DNA conformation and structural heterogeneity in chromatin and nuclear proteins,we have discussed both the significance of our results as well as technical aspects of this approach.
