ISSN 0253-2778

CN 34-1054/N

2015 Vol. 45, No. 2

Display Method:
Advance in applications of non-traditional stable isotopes in soil studies
HUANG Fang, NAN Xiaoyun
2015, 45(2): 87-100. doi: 10.3969/j.issn.0253-2778.2015.02.001
Non-traditional stable isotopes have been widely applied to the studies on the Earths surface environment during the last ten years. In the critical zone, soils continuously exchange materials and energy with the atmosphere and lithosphere with the aid of water and biota. A brief review was presented of the fractionation and potential applications of non-traditional stable isotope in soil studies. Taking Mg, Fe, Si and Hg isotope systematics as examples, a few important scientific problems of soil research were discussed, including weathering and pedogenesis, the cycle of nutrient elements between plants and soils, and heavy metal pollution. The current progresses of non-traditional stable isotopes in soil research was briefly reviewed and future directions in this field were outlined. The application of non-traditional stable isotopes in soil is a nice example of the multi-disciplinary studies combining stable isotope geochemistry, soil science, and environmental ecology.
Strong convergence for weighted sums of negatively superadditive dependent random variables
ZHENG Lulu, WANG Qiang, WANG Xuejun
2015, 45(2): 101-106. doi: 10.3969/j.issn.0253-2778.2015.02.002
Some results on the complete convergence for sequences of negatively superadditive dependent (NSD) random variables were obtained by using the Marcinkiewicz-Zygmund type moment inequality, Kolmogorov type exponential inequality and the truncated method. The obtained results extend the corresponding conclusions for weighted sums of negatively associated (NA) random variables with identical distribution to the case of sequences of NSD random variables with nonidentical distribution.
Some properties of the k-error linear complexity of ternary 3n-periodic sequences
TANG Miao, KAI Xiaoshan
2015, 45(2): 107-111. doi: 10.3969/j.issn.0253-2778.2015.02.003
Linear complexity and k-error linear complexity of periodic sequences are two important security indices of stream cipher systems. The k-error linear complexity of 3n-periodic sequences over the finite field F3 was discussed, and some of its properties and error sequences were obtained. By means of the properties, a result was presented, showing how the computation of the k-error linear complexity of a sequences with period 3n can be reduced to the same computation for sequences with period 3n-1, for any positive integer n.
9F MR imaging probe for furin detection in vitro and in living cells
WANG Dingli, LIANG Gaolin
2015, 45(2): 112-116. doi: 10.3969/j.issn.0253-2778.2015.02.004
The 9F magnetic resonance imaging (MRI) probe 1, CBT-Lys(FMBA)-Cys(StBu)-Arg-Arg-Val-Arg-Ac, was designed and synthesized. The probe can be reduced by GSH and cleaved by furin which is upregulated in several cancers to yield active intermediate. The 1,2-aminothiol group and cyano group of the intermediate condense quickly to yield the dimer which self-assembles into nanoparticles at or near the locations of furin in cells, inducing a clear turn-off of its 9F NMR signal. The nanoparticles were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), high performance liquid chromatography (HPLC). Furthermore, results of cell uptake indicate that probe 1 can be easily uptaken by tumor cells resulting in 9F NMR signal “off” for the detection of furin activity inside cells. The proposed 9F NMR probe could be potentially applied to 9F MRI in the future.
Investigation of thermodynamics of interaction between humic acids and CNTs with various oxygen contents by isothermal titration calorimetry
ZHOU Chaoqun, SHENG Guoping
2015, 45(2): 117-122. doi: 10.3969/j.issn.0253-2778.2015.02.005
The interaction between carbon nanotubes (CNTs) with various oxygen contents and humic acids (HA) was studied through batch adsorption experiments and the isothermal titration calorimetry (ITC) technique. The effects of CNTs surface chemistry and solution ionic strength were evaluated. Adsorption results show that the binding strength between CNTs and HA and equilibrium adsorption capacity of HA increase with the decrease in CNTs oxygen content decreases and the increase in ionic strength, implying that hydrophobic interaction could be one of the main interaction forces between CNTs and HA. ITC results indicate that interaction between CNTs and HA is exothermic and that a stable CNT-HA complex could be formed. CNTs solutions become more ordered after binding with HA. The negative enthalpy and entropy changes obtained from the ITC analysis imply the existence of hydrogen bonds between CNTs and HA. This could provide a better understanding of interactions between humic substances and CNTs, and thus the migration and fate of CNTs in natural environments.
Soft lithography fabricating micropatte rns of an azo-containing side-chain liquid crystalline polymer prepared by RAFT polymerization
GAO Jiangang, YU Shaobo, ZHENG Benpei, SHI Wenhua, ZHANG Qijin, LIU Jianping
2015, 45(2): 123-131. doi: 10.3969/j.issn.0253-2778.2015.02.006
A side-chain liquid crystalline polymer PCN2 was prepared by RAFT polymerization and characterized by UV-Vis, FTIR, H-NMR spectroscopies and GPC, DSC analyses, and three kinds of micropatterns of PCN2 were successfully fabricated by employing solvent-assisted micromolding (SAMIM) of the soft lithography techniques and were studied with optical microscopic and SEM investigations. The results show that the achieved PCN2 has a narrow molecular weight distribution of ca. 122, and that the micromolding method can produce fine micropatterns with a comparatively high fidelity, which are expected to be applied in the development of polymer materials with specific structures and functions.
EDXRF study on chemical composition recipe of Luochong bluish white porcelain
CUI Mingfang, ZHU Jianhua
2015, 45(2): 132-137. doi: 10.3969/j.issn.0253-2778.2015.02.007
The bluish white porcelain of Luochong kiln was first made in Five Dynasties and it was the representative of the bluish white porcelain during the early stage of Fanchang kiln. X-ray fluorescence spectrometer (EDXRF) was used to analyze the body and glaze of Luochong porcelain. And contrastive research was also made systematically with the white porcelain of Ding kiln, Jingdezhen kiln and Qingshan kiln in the Late Tang Dynasty and the Five Dynasties. Investigation and analysis conducted on the basis of polarized light microscope observations, whiteness value, water absorptivity and firing temperature indicate a strong similarity between Luochong kiln and Ding kiln. Also, the whiteness value of porcelain from Luochong kiln porcelain can be as high as that of white porcelain. And the body of the sample has a dense structure, indicating that it had reached a high fire temperature at that time.
Discretization strategies in seismic modelling and imaging for the generalized screen propagator
HU Jinyin, JIA Xiaofeng
2015, 45(2): 138-149. doi: 10.3969/j.issn.0253-2778.2015.02.008
Defining an appropriate discrete grid is a crucial part of frequency-domain modelling and imaging. The results of the illumination analysis, modelling and migration were applied to investigate the relationship among time step, trace interval and spatial grid interval for the Padé generalized screen propagator. Numerical tests indicate that the stability condition must be satisfied when defining grid discritization strategies, or the frequency-domain migration result could be mistakenly interpreted due to the existence of unexpected coherent noise. Besides, when migrating the insufficient spatial-sparse-sampling data, the spatial grid doesnt have to be too fine. And the regular interpolations among traces can hardly improve the migration result. Therefore its more reasonable to inject zero-value traces on grid points between adjacent receivers than using interpolation. This study provides an important reference for efficiently defining discrete grids for other frequency-domain methods.
Eutrophication and water quality characteristics of Western Chaohu Lake in winter via planktonic alga diversity analysis
LI Meng, LIU Guijian, WU Lei, LIU Rongqiong, WANG Jiaquan
2015, 45(2): 150-158. doi: 10.3969/j.issn.0253-2778.2015.02.009
Grid sampling method was employed to collect the planktonic alga from western half of Chaohu Lake in winter. The individuals, chlorophyll content and community structure of planktonic alga were determined and identified. The results show that positive correlation is observed between chlorophyll contents and alga density. Both chlorophyll contents and alga density decrease gradually from the estuaries to other parts of the lake, and this tendency is also found in the vicinity of Gushan island, one of the islands in the lake. The predominant phylum is Cyanophyta, and the dominant species include Microcystis, Euglena, Chlorella, Melosira and Anabaena. Moreover, the contamination status and the degree of eutrophication in the lake were evaluated by using various biological assessment methods including chlorophyll content, index of chlorophyll contents, index of special planktonic alga, and diversity indexes (Shannon-weaver, evenness, abundance and dominance). The results indicate that the western half lake is moderately nutritional and lightly contaminated, and that an elevated degree of eutrophication and contamination is observed in the estuaries of the lake and the vicinity of the island.
LES of flow structure control of a round jet by acoustic excitation
TANG Bing, ZHU Minming, LIU Minghou, YE Taohong, CHEN Yiliang
2015, 45(2): 159-167. doi: 10.3969/j.issn.0253-2778.2015.02.010
To investigate flow field structures of a round jet controlled by acoustic excitation, large eddy simulation (LES) was performed to calculate a round jet (Re=2 020) under phase-locked global acoustic excitation. The control effects on the velocity and vorticity fields were described in various perspectives, and the frequency selectivity of jet response was analyzed. The preferred model frequency of unmodulated jet agreed well with the experiments. The mean and root mean square (RMS) velocity, probability density functions (PDF), skewness, kurtosis and momentum thickness were used to explore the modification of velocity fluctuation and mixing properties. Vortical structures were illustrated by Q criterion and instantaneous vorticity. The key vortex structure in the modulated cases was identified as Hills sphere vortex. It is concluded that acoustic excitation can effectively control the flow field. Especially when the modulation frequency is near the preferred mode, a small amount of modulation energy input can cause significant change in flow structures.
Investigation on smoke toxicity of the novel intumescent flame retardant LDPE composites based on the mice experiment
NIE Shibin, ZHOU Can, ZHANG Chi, PENG Chao, PENG Wei, HU Yuan
2015, 45(2): 168-172. doi: 10.3969/j.issn.0253-2778.2015.02.011
The smoke toxicity of the novel flame retardant low-density polyethylene (LDPE) composites with good flame retardant properties and excellent water resistance was studied by mice experiments, and the upper limit of the no death smoke concentration of the smoke was assessed. Furthermore, different heating temperatures were selected to research the smoke toxicity for the flame and flameless combustion. The results show that the smoke toxicity of the flame retardant LDPE composites with flame combustion is much smaller than that with the flameless combustion. Meanwhile, fire risk assessment of flame retardant LDPE composites is achieved by fire performance index and fire development index. The work provides some experimental data for preparing environment-friendly flame retardant LDPE composites with excellent properties.