ISSN 0253-2778

CN 34-1054/N

2012 Vol. 42, No. 1

Display Method:
High resolution Sr/Ca profiles of three Tridacna specimens and their potential as sea surface temperature proxy
SHAO Da, YAN Hong, WANG Yuhong, SUN Liguang
2012, 42(1): 1-9. doi: 10.3969/j.issn.0253-2778.2012.01.001
Three modern Tridacna specimens of different species were collected from Xisha Islands of South China Sea and the high-resolution Sr/Ca ratios of their inner shells were analyzed. Two Sr/Ca profiles of Tridacna (Tridacna gigas, Tridacna squamosa) display regular seasonal variations and close correlation with the instrumental sea surface temperature (SST) of the studied area. Four statistically significant models were proposed based on the linear regression of the Sr/Ca ratios (monthly or weekly values and extreme values) and the SST. These models could be used to reconstruct the SST of Holocene from the Sr/Ca ratio of Tridacnas inner shells.
Geochemistry of rare earth elements (REEs) in coal from magmatic intrusion area from Wolonghu Coal Mine
JIANG Mengmeng, LIU Guijian, WU Bin, ZHENG Liugen
2012, 42(1): 10-16. doi: 10.3969/j.issn.0253-2778.2012.01.002
Magmatic rock samples and adjacent coal samples were collected from a vertical section in the Wolonghu Coal Mine, Huaibei. The chemical extraction experiments were carried out, and the abundances of rare earth elements (REEs) in samples and coal ashes were determined by inductively couple-plasma mass spectrometry (ICP-MS). The occurrences of REEs were studied using sequential chemical extraction Experiment (SCEE) in different extraction liquids and conditions. The characterizations of the concentration, distribution patterns and the occurrence of REEs were analyzed. The results show that exchange of material between the magma and the coals occurred in the process of magmatic intrusion. Due to the superimposition of coal-forming microenvironment and magmatic intrusion, the distribution patterns of magma and coals are different. The result of SCEE shows that REEs are mainly distributed in sialic state, and that the source of REEs is terrigenous.
Distribution characteristics of Zn,Pb,Cd,Cu in soil and crops around Xinzhuangzi Coal Mine waste rock pile
WANG Xingming, DONG Zhongbing, LIU Guijian, MEI Jingliang
2012, 42(1): 17-25. doi: 10.3969/j.issn.0253-2778.2012.01.003
Samples of soils and crops were collected around Xinzhungzi Coal Mine waste rock pile by the intercept method. The concentrations of Zn, Pb, Cd, Cu in the soils and crops were analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). The results showed that the soil is alkaline, and the max concentrations of Zn, Pb in the soils are 4308 mg·kg-1 and 1561 mg·kg-1 at the depth of 20~40 cm, which are below the background values of Huainan soil. The concentrations of Cd and Cu in the soil with the depths of 0~20 cm and 20~40 cm, respectively, are the highest and 10676% and 046% higher than the background value of Huainan soil. The concentrations of Zn, Pb, Cd, Cu are incorrelate with the depth of soil. The Zn and Pb in the top soil (0~20 cm) reach their peak values at a distance away from the coal mine spoil, which may be caused by the grain from the burst of coal mine spoil transported by the wind. The stepwise regression analysis indicated that total P affects the concentrations of Zn and Pb in soil, and organic matter affects the concentrations of Pb and Cu in soil. Cd accumulates in the roots of soybean and rice, while Zn transports into the aerial parts of the two plants. The enrichments of Zn in the aerial parts of soybean and rice are much higher. The order of Zn, Pb, Cd, Cu enrichments in the leaf, hull and seed of soybean and rice is Zn>Cu>Cd>Pb. The max value of Pb in the grain of rice is 052 mg·kg-1(dry weight), 13 times higher than the national food hygiene standard. The risk from the Pb in the seed of rice should not be overlooked.
Analysis of distribution and environmental assessment of antimony in collapse lake waters of Huaibei mining areas
LIU Fei, WANG Xin, ZHU Pengfei
2012, 42(1): 26-30. doi: 10.3969/j.issn.0253-2778.2012.01.004
Antimony is a hazardous trace heavy metal with wide distributions. It is chronically toxic and potentially carcinogenic to the human body. Water samples were collected from the collapse lakes of three mines and a background water body in Huaibei mining areas in different periods, and at depths of 20 cm, 50 cm and 80 cm. The samples were determined by hydride generation atomic fluorescence spectrometry(HGAFS). The results show that the concentration distributions of antimony are significantly different in diverse water bodies of collapse lakes, which might be related to such factors as length of collapse time and distance to the gangue pile. The vertical distribution of antimony concentrations in the same collapse lake is characterized by slowly increased concentration from the surface to the deep.Based on the single-factor contaminant index and the environmental quality standards for surface water, an environmental assessment of antimony contamination in the collapse lakes was conducted to provide references for the comprehensive utilization of water.
Design of compact coils and a big stable current driver for Feshbach resonance researches
HAN Mingfei, ZHANG Jinyi, YAN Bo, CHEN Shuai
2012, 42(1): 31-36. doi: 10.3969/j.issn.0253-2778.2012.01.005
Atomic Feshbach resonance is one of the important tools in quantum gases experiments. The position of a resonance, B0, typically occurs at a few hundred gauss for alkali atoms. The width of a resonance Δ can be relatively smaller, thus requires a stable magnetic field. A set of compact Helmholtz coils were designed, which are capable of carrying a high current for the strong magnetic field while maintaining the required stability. The negative integral feedback loop was used to regulate a current stability up to 10-5.
Backgrounds studies on D0→K0sπ+π- decay in the mixing parameters measurement of neutral D meson at Belle
PENG Tao, LI Longke, ZHANG Ziping
2012, 42(1): 37-40. doi: 10.3969/j.issn.0253-2778.2012.01.006
In the asymmetrical e+e- collider experiment at Belle, a sensitive measurement of D0-D0 mixing parameters can be obtained from a time dependent Dalitz analysis of D0→K0sπ+π- decay channel. The related event selection and background studies were discussed, and all the distribution functions of signal and backgrounds were given.
Numerical study on combustion in a porous medium with Pt catalyst
XING Dan, LIU Minghou, XU Kan
2012, 42(1): 41-46. doi: 10.3969/j.issn.0253-2778.2012.01.007
Using the Deutschman CH4/air/Pt surface reaction mechanism and GRI30 gas phase reaction mechanism, combustion of CH4/air premixed gases in a porous medium burner with Pt catalyst was numerically studied based on the volume averaged two-temperature model. Compared with the results of the inert porous medium burner, it is found that the flame front moves forward with Pt catalyst, and becomes more evident with the increase of the mass flow rate. In the catalyzed porous media burner, both the solid and gas temperature distributions are more uniform and the maximum temperature is lower than that in the inert burner. The introduction of the catalyst can reduce the size of the burner and bring down pollutant emissions.
Characteristics of discharge in porous ceramics at atmospheric pressure
NI Weijie, ZHOU Zhipeng, LIANG Lipeng, ZHANG Jimin, LI Hui
2012, 42(1): 47-51. doi: 10.3969/j.issn.0253-2778.2012.01.008
The microdischarges generated inside porous ceramics by AC high voltage represent a novel way to create stable atmospheric pressure plasmas. The physical characteristics of discharge in porous ceramics were investigated by photographic visualization and electrical measurements. Experimental results show that the surface discharge is not converted into pore microdischarges, and the onset voltage of pore microdischarges increases with the thickness of ceramics, while significantly decreasing with increasing porosity of ceramics.
A SAR image segmentation algorithm based on local median fitting C-V model
ZHANG Qian, HUANG Jianghua, ZHANG Rong, LIU Zhengkai
2012, 42(1): 52-59. doi: 10.3969/j.issn.0253-2778.2012.01.009
A novel SAR image segmentation algorithm LMFCV-SIS based on local median fitting (LMF) C-V model was proposed according to the characteristics of SAR images. The main idea of the algorithm is to use the LMF of the pixel and its neighbors to form an energy and the final evolution of the curve was given by the minimization of the energy. The performance of the approach was verified by plenty of real airborne SAR images and the experimental results from the real data show its efficiency and accuracy.
Face sketch synthesis and recognition based on independent subspace
DANG li, KONG Fanrang
2012, 42(1): 60-66. doi: 10.3969/j.issn.0253-2778.2012.01.010
Face sketch recognition plays an important role in determining the identity of the suspect through suspect sketch which is described by witnesses. In order to better realize face sketch recognition, a new face sketch synthesis and recognition algorithm was proposed based on face independent subspace and shape features. According to the face reconstruction based on independent component analysis (ICA) subspace, the face sketch synthesis based on ICA was studied, and the conversion between photo and sketch was realized. Considering the important role of the face structure information in face recognition and in analyzing the limitation of the structural information extracted by active shape model (ASM) algorithm, the polar shape model (PSM) was proposed. Finally, the synthesised sketch was recognized with the one to be recognized by combining ICA/linear discriminant analysis (LDA) and PSM. Experiment results indicate that the synthesis sketch performs very well by new algorithm, the recognition rate of one rank is 947%, and the recognition rate of ten rank is 991%. Recognition with subspace and PSM, one rank rate can be increased by 53%, and the first three rank rate can be increased by 42% evenly. The algorithm has higher recognition rate and basically meets the requirements of automatic face sketch recognition system.
A multidimensional security index system and quantitative level protection model
ZHOU Huansheng, JIANG Jianhui
2012, 42(1): 67-76. doi: 10.3969/j.issn.0253-2778.2012.01.011
A multidimensional security index system was established by integrating information security measurements and allocation of information security levels. A quantitative level protection model based on security index was proposed. The security index of a system was evaluated by using a hierarchical method based on grading. The problem of security level allocation was abstracted as a kind of linear programming problem. Compared to models using conventional methods, the proposed model is more quantifiable and operable. The application of the model was illustrated with an example of a real information system.
Dynamic watermarking algorithm based on chaotic optimization
LUO Yangxia, FANG Dingyi
2012, 42(1): 77-84. doi: 10.3969/j.issn.0253-2778.2012.01.012
In order to improve the stealth and robustness of software watermarking, the chaos theory was applied to the software watermarking algorithm, mainly by optimizing and improving the dynamic graph CT algorithm based on chaos-replacement and chaos-encryption. Chaos-based dynamic watermarking algorithm (CBDW) was achieved under the VC60 C++ environment, and some analyses were conducted. Experimental results demonstrate that, while maintaining its advantage of high data rate, the proposed approach is effective in enhancing stealth and robustness of the original watermark.