ISSN 0253-2778

CN 34-1054/N

2011 Vol. 41, No. 1

Display Method:
Duration measurement in geological sciences — A geophysical approach
LIU Deliang
2011, 41(1): 1-8. doi: 10.3969/j.issn.0253-2778.2011.01.001
There are two ways of measuring the time structure of geological events: the time-point at which an event occurred and its duration. Although the isotopic geochronological method, after nearly a century of development, is now a mature approach to the time-point measurement of a geological event (generally with a precision of a millions years error), it is incapable of measuring its duration. The measurement of a geological event from beginning to end requires an insight into structural geochronology, a new field at the forefront of international research. A geophysical approach was thus proposed (generally with a precision of 104 years error ). The approach can be divided into four steps: tectonic-geological work — observation of order and intensity of tectonic reworking; tectonic-physical work — measurement of differential stress and strain rates, a basic component in geological dating; tectonic-chemical work — calculating volumetric factors of deformed geological bodies; and tectonic-mathematical work — calculating the duration of structure formation. The approach has been applied to the study of the ductile zone in East and Southwest China and some results have been achieved. The approach is not yet mature and further improvement is needed for it to qualify as an effective theory of structural geochronology. The prospects of structural geochronology were given and its application limitations were pointed out.
Partition characteristics and correlation of heavy metal between sediment and surface water from Chaohu Lake
LI Guolian, LIU Guijian, JIANG Mengmeng, WANG Ruwei, ZHENG Liugen
2011, 41(1): 9-15. doi: 10.3969/j.issn.0253-2778.2011.01.002
Twenty seven samples of water and sediment were collected in the three main estuaries (Nanfei River, Yuxi River, and Hangbu River) of Chaohu Lake respectively. The heavy metal(Cd, Cr, Cu, Pb, Zn, As, Hg)contents in the sediment and the dissolved contents in the water were tested with precision instruments such as ICP-OES and AFS, partition coefficients between sediment and surface water were calculated, and any correlation between two elements was analyzed for each estaury. Physical and chemical analysis of water quality indicated that the contents of TN and TP are higher than the limits of the Class Ⅴ environmental quality standard in the rivers. The results of element test showed that the contents of heavy metal elements except mercury are lower than Class Ⅰenvironmental quality standard basically while sediment contents exceed the background values for a great number of sediment samples. The pollution is most serious at the entrance of Nanfei River, partiton coefficients of element Cr, Cu, Pb, Zn and As are lower than those of the others. However, the partition coefficents of heavy metal Cd and Hg are lowest in the Hangbu River, and there is good correlation among the 3 elements of Cu,Cd and Hg.
Identification and denitrification activity of an isolated denitrifier
LIU Yong, QIAN Jiazhong, WEI Zhaojun, WANG Lulu
2011, 41(1): 16-21. doi: 10.3969/j.issn.0253-2778.2011.01.003
In order to research the mechanism of nitrate-contaminated groundwater bioremediation, a heterotrophic denitrifier was isolated and identified from the reed-wetland in Chaohu lake, and its denitrification activity was studied. Denitrifer was isolated on sodium potassium tartrate agar, and 16S rDNA identification and phylogenetic analysis of the strain were performed. The influence of solo carbon source and C/N ratio on the denitrification activity was studied and the suitability of the strain for nitrate content in water was researched. A heterotrophic denitrifier with high denitrification activity was isolated and named DB-1. The isolated strain was gram negative, a facultative anaerobe, and a micrococcus bacterium. The 16S rDNA sequence analysis revealed that strain DB-1 had a similarity of 996% to Klebsiella sp. When sodium acetate was used as carbon source, NO-3-N could be removed almost completely from water at 120 h while keeping C/N ratio of 3 and the initial nitrate concentration was 100 mg/L. The strain DB-1 was a heterotrophic denitrifier, with extensive carbon source scope and capable of removing nitrate effectively from water.
Test and preliminary analysis of porcelains from Shouzhou kiln
YIN Ruochun, YAO Zhengquan, LI Yinghua, WANG Changming
2011, 41(1): 22-28. doi: 10.3969/j.issn.0253-2778.2011.01.004
The composition and firing temperature of Shouzhou porcelains were analyzed using energy dispersive X-ray fluorescence (EDXRF) technology and thermodilatometry, respectively. The results indicate that: Shouzhou porcelain has the feature of high-aluminum and low-silicon in porcelain body; the porcelain glaze of Shouzhou kiln is calcareous glaze and the difference of celadon and yellow glaze probably results from variant oxidizing conditions in the kiln instead of the difference of colored elements contained in glaze; the firing temperature of celadon porcelains from Guanzuizi kiln is above 1 200 ℃, and that of yellow glaze porcelains from Zhuyuanbu kiln is above 1 100 ℃ and about 1 200 ℃.
Circadian rhythms in rat pineal melatonin synthesis under constant darkness conditions
LIU Yajing, LU Zhongmin, ZHU Hongyan, TAN Zhonglin, ZHOU Jiangning
2011, 41(1): 29-34. doi: 10.3969/j.issn.0253-2778.2011.01.005
To investigate whether rat pineal cell is capable of generating a circadian oscillation in melatonin release,the cultured pineal cell in culture medium was collected at 6∶00, 8∶00, 10∶00, 12∶00 and 15∶00 during the day, and at 18∶00, 20∶00, 22∶00, 1∶00 and 4∶00 at night respectively. The melatonin level in culture medium was measured by a direct radioimmunoassay. The complex cosine functions (CCF) statistical analysis indicates that the rat pineal cell melatonin synthesis shows an intrinsic rhythm at 3, 6, 9 day culture under constant dark conditions. However, the intrinsic rhythm disappears at 12 day culture. This result suggests that the rat individual pineal cells can function as a circadian oscillator in vitro.