JUSTC

Concentrations, distributions, and source of polycyclic aromatic hydrocarbons in soil of Luling Coal Mine in Huaibei

LIU Jingjing, WANG Ruwei, LIU Guijian, ZHANG Jiamei

2010, 40(7): 661-666. doi: 10.3969/j.issn.0253-2778.2010.07.001

Abstract:
17 representative soil samples and 1 coal slack sample were collected in the surroundings of Luling Coal Mine in Huaibei Province, China. The concentrations of polycyclic aromatic hydrocarbons (PAHs) in the collected samples were detemined by gas chromatography equipped with a mass spectrometry detector (GC-MS). The distribution and transportation behavior of PAHs were analyzed and the environmental impact of the PAHs in the soil of the coal mine was further evaluated. The results showed that the concentrations of 28 PAHs in the collected soil samples ranged from 035 to 621 μg/g, with an average concentration of 169 μg/g, among which 16 PAHs are USEPA priority PAHs. The total contents of these 16 PAHs ranged from 023 to 353 μg/g, with the average contents being 100 μg/g. Compared with the relevant standards of organic pollutants in the soil, these typical regions were moderately or highly polluted according to the concentrations of ∑16PAHs. It was further discovered that the sources of PAHs were gob piles and combustion of biomass. A toxicity assessment indicates that the environmental risks for PAHs are mainly BghiP whoseTEQ accounts for 6068% of the total value.

Effect of organic carbon on nitrate removal in groundwater

WANG Zhiping, SUN Shiqun, QIAN Jiazhong, CHEN Zhou

2010, 40(7): 667-672. doi: 10.3969/j.issn.0253-2778.2010.07.002

Article Views:206 Full article PDF

Abstract:
The factors influential on nitrate removal in groundwater were studied in laboratory equipment containing unprocessed reed stalks and sand and the rule governing nitrite accumulation was found. The results showed that: ①Negative correlation existed between the TOC and NO-3-N, while negative correlation existed between the NO-3-N and HCO-3. ②Some TOC was demanded if the NO-3-N was to meet the quality standards(20 mg·L-1). ③Nitrite accumulated when the C/N ratios were less than 1.00 and there were some rules between nitrite accumulation and C/N ratios. The optimal C/N ratio was assumed to be 100, at which more removal of NO-3-N is achieved with less excess TOC and NO-2-N in the effluent.

Starvation induced MTP expression in part through HNF4α

QU Linbing, TAN Wenjuan, GUAN Min, WONG Chiwai, CHEN Ling

2010, 40(7): 673-678. doi: 10.3969/j.issn.0253-2778.2010.07.003

Article Views:240 Full article PDF

Abstract:
Hepatocyte nuclear factor 4α (HNF4α) is an important transcription factor governing the expression of genes involved in multiple metabolic pathways. Microsomal triglyceride transfer protein (MTP) is a rate-limiting enzyme played a role in the assembly and secretion of very low density lipoproteins (VLDLs). Fasting induces MTP expression in C57BL/6J mice. In HepG2 cells, we further demonstrate that starvation induces MTP expression, meanwhile enhances HNF4α mRNA level. It was found that MTP is an HNF4α target gene. Moreover, adenovirus mediated HNF4α overexpression and HNF4α agonists induce MTP expression in HepG2 cells. HNF4α specific siRNA represses HNF4α and MTP expression. These results suggest that starvation induces MTP expression in part through HNF4α.

Nonparallel accumulation of synonymous and non-synonymous substitutions on human and chimpanzee chromosomes

SONG Yumei, CHEN Xi, CHEN Xueping

2010, 40(7): 679-685. doi: 10.3969/j.issn.0253-2778.2010.07.004

Article Views:224 Full article PDF

Abstract:
To reveal the evolutionary dynamics of primate chromosomes, using mice and dogs as backgrounds, we analyzed a total of 61949 pairs of genes by comparative genomics and bioinformatics methods, which included 16 427, 15 161, 15 802 and 14 559 ortholog pairs identified, from human-mouse, human-dog, chimpanzee-mouse and chimpanzee-dog phylogenies respectively. The results show that, in humans and chimpanzees, genes on chromosomes 16, 19, 21 and 22 have featured significantly higher synonymous substitution rates (dS). Analysis of human-mouse-dog and chimpanzee-mouse-dog ortholog trios also indicates dS and non-synonymous substitution rates (dN) to be homogeneous across different phylogeny branches, suggesting that the relevant genes have been subjected to similar selection for base substitution rates. The analysis also suggests that local chromatin environment, such as GC content and gene density, may contribute to the accumulation of both types of substitutions on human chromosomes. Furthermore, recombination rates seem to have a significant influence on the dS of human chromosomes.

Determination of tyrosine based on NaBrO3-Malic acid- [CuL](ClO4)2-H2SO4 oscillating system

SHEN Hui, ZHANG Zude, HU Gang

2010, 40(7): 686-693. doi: 10.3969/j.issn.0253-2778.2010.07.005

Article Views:224 Full article PDF

Abstract:
A new quantitative analytical method for the determination of tyrosine by the perturbation caused by different amounts of tyrosine on the NaBrO3-Malic acid-[CuL](ClO4)2-H2SO4 oscillating chemical system is reported. The unsaturated ligand L in the complex [CuL](ClO4)2 is 5，7，7，12，14，14-hexemethyl-1，4，8，11-tetraazacyclotetradeca-4，11-diene. When different concentrations of tyrosine is injected into the oscillating chemical system, the mutation of the amplitude ΔAm fits a linear relationship to the logarithm of the concentration of tyrosine lg{[Tyr]0} in the range 1235×10-6~2677×10-4 mol/L very well. The correlation coefficient is 0999 18. The experimental results also show that there is the linear relationship between the change in the oscillating period ΔT of the chemical system and the logarithm of the concentration of tyrosine lg{[Tyr]0} in the range 7444×10-7~4534×10-4 mol/L. The correlation coefficient is 0993 61. The effect of influential variables, such as temperature, stirring rate and the concentration of components on the oscillating system are studied. Some aspects of the probable mechanism of perturbation of tyrosine on the oscillating chemical system are also discussed.

Detection of hydrogen peroxide in neutral solution

LIU Jinping, ZHOU Baineng, BAI Xue, TAN Wenguang, WU Shouguo

2010, 40(7): 694-698. doi: 10.3969/j.issn.0253-2778.2010.07.006

Article Views:210 Full article PDF

Abstract:
Glassy carbon electrode modified by cellulose-acetate-covered Prussian blue was fabricated as a novel hydrogen peroxide sensor. The modified electrode showed an excellent electrocatalytic activity for H2O2 reduction in neutral solutions. H2O2 was thus detected amperometrically in pH 70 phosphate buffer solutions at an applied potential of -0.2 V (vs SCE). The response current was proportional to the concentration of H2O2 in the range of 1.0×10-5~2.5×10-4 mol/L with the detection limit of 22×10-6 mol/L at a signal to noise ratio of 3, RSD=0999 4. The sensitivity was estimated to be 190 mA·L·cm-2·mol-1. In addition, the modified electrode exhibited an excellent operational stability.

Effects of post-annealing in hydrogen atmosphere on the properties of Al-doped ZnO films

GAN Liuzhong, WU Bingjun, Huang Feng, LI Ming, XIE Bin

2010, 40(7): 699-705. doi: 10.3969/j.issn.0253-2778.2010.07.007

Article Views:256 Full article PDF

Abstract:
Transparent conductive ZnO:Al (AZO) films were deposited on glass substrates by radical assisted magnetron sputtering. The effects of post-annealing in hydrogen atmosphere on the Al doping efficiency and properties of AZO films were investigated. It was found that post-annealing treatment improves the Al doping efficiency and reduces the concentration of neutral impurity scattering centers. These two factors together improve the conductivity of AZO films. The resistivity and the transmittance at 550 nm of the AZO films annealed in H2 at 550 ℃ were 65×10-4 Ω·cm and 857%, respectively, with carrier concentration being 33×1020 cm-3 and mobility of 297 cm2·V-1·s-1.

Studies on the adsorption of aromatic compounds onto adsorbent resin

ZHANG Jiazhi, HUANG You, LIU Wei, LIANG Haojun

2010, 40(7): 706-711. doi: 10.3969/j.issn.0253-2778.2010.07.008

Article Views:188 Full article PDF

Abstract:
The static equilibrium adsorption of phenol, aniline, p-chlorophenol, p-chloroaniline in the pure component system, and phenol—aniline, p-chlorophenol—p-chloroaniline in the two-component system on DA201-CⅡ were investigated at different temperatures. The results show that all the adsorption isotherms of pure component system are correlated with Freundlich equation within the studied range of temperature and concentration, and that the adsorption capacity follows the order phenol

Effect of La3+ on corrosion behavior of Zn-Fe alloy coating in sulfuric acid solution

LU Daorong, WANG Liangliang

2010, 40(7): 712-717. doi: 10.3969/j.issn.0253-2778.2010.07.009

Article Views:202 Full article PDF

Abstract:
The effects of Lanthanum ions on the corrosion behavior of Zn-Fe alloy coating in acid corrosion solution，which was electroplated on the surface of A3 steel substrate with various electrolytes of Lanthanum salt，were investigated. The corrosion behavior of the Zn-Fe alloy coating was studied by the Linear sweep voltammetry and AC impedance in the 020 mol·L-1 sulfuric acid solution at 30 ℃. The microstructure and shape of Zn-Fe alloy coating before and after corrosion was studied by XRD and SEM. The results indicate that the addition of lanthanum salt decreases the grain size of Zn-Fe alloy coating and retains the preferred orientation of Zn-Fe alloy coatings, but affects the intensity of diffraction for crystal planes. When 090 g·L-1 La2(SO4)3 is added in the electrolytes, the coatings of Zn-Fe alloy are more uniform and compact, and the electrocrystallization appears layered. The Jpp and Jp of Zn-Fe alloy coating are reduced evidently, Rp is increased, and the Zn-Fe alloy coating has better corrosion resistance.

Effect of CdCl2 annealing treatment on interdiffusion and reaction at the CdS/CdTe interface

HOU Zerong, WAN Lei, BAI Zhizhong, WANG Deliang

2010, 40(7): 718-726. doi: 10.3969/j.issn.0253-2778.2010.07.010

Article Views:265 Full article PDF

Abstract:
A structure of Glass/FTO/CdS/CdTe/CdS based on the CdTe solar cell (Glass/FTO/CdS/CdTe) was adopted to study the effect of CdCl2 annealing treatment on the interdiffusion and the related reaction at the CdS/CdTe interface. Investigations show that surface morphology changs dramatically under different annealing treatment temperatures. The crystal size of CdS increases from 20 nm to 70 nm between 300～350 ℃. This temperature range is consistent with that of the CdS sphalerite to wurtzite phase transformation. CdS/CdTe interdiffusion happens at around 350 ℃, and CdS0.85Te0.15 with hexagonal-wurtzite structure is detected at 550 ℃. The CdS is quickly consumed up through interdiffusion with CdTe and forming CdSxTe1-x alloy. CdTeO3 begins to form at 450℃. Raman scattering shows that the intensity of CdS 1LO peak decreases from 350 ℃ and shifts to lower frequency, which reveals the formation of CdSxTe1-x. The XPS spectrum of samples confirms the formation of CdSxTe1-x and CdTeO3. CdCl2 protects CdS/CdTe from oxidation and promotes interdiffusion at the interface and formation of CdSxTe1-x during air annealing.

Preparation of visible light response N-F-codoped TiO2 nanorod arrays and their photocatalytic performances

LV Yan, FU Zhengping, YANG Beifang

2010, 40(7): 727-733. doi: 10.3969/j.issn.0253-2778.2010.07.011

Article Views:213 Full article PDF

Abstract:
An efficient method for the preparation of visible light response N-F-codoped TiO2 nanorod arrays (TNRAs) is reported. In the process, simultaneous nitrogen and fluorine doped TNRAs on the glass substrates were achieved by liquid phase deposition (LPD) method using ZnO nanorod arrays as templates. The as-prepared samples were characterized by SEM, TEM, Raman, XPS and UV-vis. The visible light photocatalytic activity of all samples was evaluated by photodegradation of methylene blue (MB) in aqueous solution. It was found that N-F codoping exhibits significant improvement of visible light absorption and the N-F-codoped TNRAs samples calcined at 450 ℃ for 2 h demonstrate the best visible light activity in all samples. The excellent photocatalytic activity can be ascribed to the synergetic effect of the unique 1D nanorod arrays structure and some beneficial effects induced by the appropriate amount of N and F doping in TNRAs.

Study on thermal property measurement method considering thermal contact resistance of the thermal probe

CHENG Wenlong, MA Ran, LIU Na, XIE Kun

2010, 40(7): 734-738. doi: 10.3969/j.issn.0253-2778.2010.07.012

Article Views:213 Full article PDF

Abstract:
A thermal properties measurement method is proposed, based on the exact solution of the thermal probe problem, in which the thermal contact resistance is considered. Thermal conductivity, specific heat capacity and other thermal properties can be measured with the utilization of the Monte Carlo inversion and a layered correction method. The thermal conductivities of several liquid and solid samples were measured, and the effects of various methods were analyzed and compared. The results show that the average measurement deviation is about 11% and a higher precision is obtained with the method presented. For the low precision inversion of specific heat capacity, a layered correction method was adopted and the average measurement deviation could reach 26%, thus greatly enhancing the measurement accuracy. The measurement results show that the thermal contact resistance has a great effect on the thermal conductivities of solid samples, but has little or no effect on liquid samples or on the specific heat capacity of all samples.

Experimental study on performance of SiC porous medium radiator

LU You, LIU Minghou, XU Kan, ZHANG Long, XU Sheng

2010, 40(7): 739-744. doi: 10.3969/j.issn.0253-2778.2010.07.013

Article Views:199 Full article PDF

Abstract:
A SiC porous medium radiator (PMR) with heat recuperator was built and its performance was experimentally studied. The effect of equivalence ratio and combustion power on ignition, combustion characteristics and radiant efficiency were evaluated. The results indicate that increasing the combustion power can lead to higher surface temperature and lower temperature gradient at a fixed equivalence ratio, and that there is an optimal equivalence ratio at which the lowest gradient is gained at a fixed power. Assisted with heat recuperator, uniformity of surface temperature along the axial direction and radiant efficiency increase. Equivalence ratio and combustion power have significant effect on radiant efficiency. At low power, increasing power results in obvious augment in radiant efficiency. There is an optimal equivalence ratio leading to a perfect radiant efficiency for a given operating power. The setup in this paper can gain a radiant efficiency as high as 347% at power 70 kW and equivalence ratio 075 without thermal recuperation. With heat recuperation, however, the optimal equivalence ratio drops to 054 and the corresponding radiant efficiency reaches 369%.

Simulation of the dynamic performance of automotive adsorption air conditioning system

MAO Huafang, HU Peng, GAO Jingxuan, CHEN Zeshao

2010, 40(7): 745-750. doi: 10.3969/j.issn.0253-2778.2010.07.014

Article Views:191 Full article PDF

Abstract:
The dynamic performance of the adsorption refrigeration system driven by engine exhaust heat was theoretically studied. Based on the linear driving force (LDF) mass transfer model, a two-dimensional non-equilibrium adsorption coupled with heat and mass transfer model was proposed for the zeolite/foam aluminum composite adsorbent-water adsorption refrigeration system, and the equations were solved with control volume method. Then, with some typical operating conditions of automotive engine in actual, the performance of the system with an engine speed from high to low, low to high and suddenly changing conditions was simulated and analyzed. The results show that the adsorption refrigeration system used in automotive air-conditioning can adapt to the changing working conditions of motor vehicles through the adjustment of cycle time.

Studies on ghosting fire from pool fire in closed compartments

LI Changhai, LU Shouxiang, YUAN Man, ZHOU Yang

2010, 40(7): 751-756. doi: 10.3969/j.issn.0253-2778.2010.07.015

Article Views:209 Full article PDF

Abstract:
Ghosting fire is a unique fire behavior which usually occurs under specific conditions with low ventilation. A series of fire tests were conducted in a 1755 m3 closed compartment without vent to find out whether ghosting fires occur in compartments under no vent conditions. The results show that ghosting fires occurred in all the 1755 m3 fire tests when fuels boiled. The large amounts combustible gases produced by boiling and low oxygen entrained to flame zone result in redundant combustible gases flowing to somewhere far from the fuel zone, where the gases mix with oxygen and the ignition condition is reached, causing ghosting fires to occur. The travel distances of ghosting fires become longer as the pool position gets higher, while the beginning time and duration of ghosting fires with regard to the pool position do not simply increase or decrease.

Experimental study on effects of longitudinal air flow on burning rate of square ethanol pool fires

LI Quanwei, QIN Jun, TANG Haidong, NI Jiadi, LIAO Guangxuan, ZHOU Yupeng

2010, 40(7): 757-763. doi: 10.3969/j.issn.0253-2778.2010.07.016

Article Views:185 Full article PDF

Abstract:
The effects of a longitudinal air flow ranging in speed from quiescent to 395 m/s on the burning rate of square ethanol pools ranging in size from 4 cm×4 cm to 9 cm×9 cm were studied experimentally in a low-turbulence wind tunnel. Based on the experimental results, the mechanism of how the burning rate is affected by the air flow was discussed. The results show that for all pools tested when the flow speed is quiescent the burning rate of ethanol per unit area was basically constant. And the burning rate increased monotonically with the increase of flow air speed. The main reason for ventilation to speed up the burning rate of ethanol pool fires is that it enhances the heat feedback to the pool, which plays a far more important role than ventilation speeding up the evaporation rate by forced convection. With the increase in air flow speed, the heat feedback to the fuel surface plays an increasingly dominant role in the burning rate than that to the downward side wall of the pool.

Effects of uncertainty associated with heat release rate on available safety egress time

KONG Depeng, LU Shouxiang, FENG Lei, LO Siuming

2010, 40(7): 764-770. doi: 10.3969/j.issn.0253-2778.2010.07.017

Article Views:202 Full article PDF

Abstract:
The effects due to uncertainties associated with fire growth rate and maximum heat release rate (HRR) on available safe egress time (ASET) were analyzed using the Monte Carlo simulation based on Latin hypercube sampling. The smoke layer height and temperature were employed as tenability critical criteria, and ASET was calculated by ASET-B model. The results indicate that the effect due to uncertainty associated with maximum HRR on ASET is more significant when the maximum ranges from 0MW to 1MW. For values between 1 MW and 4 MW, a greater effect from fire growth rate than maximum HRR is evident on ASET. When the uncertainty of maximum HRR ranging from 4 MW to 8 MW is considered alone, ASET is a deterministic rather than stochastic value. The uncertainty of ASET is propagated by fire growth rate.

2010 Vol. 40, No. 7

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