Zhang J.-B.,Ningbo Entry Exit Inspection and Quarantine Bureau |
Wang Q.,Ningbo Entry Exit Inspection and Quarantine Bureau |
Lin L.,Ningbo Entry Exit Inspection and Quarantine Bureau |
Luo M.-G.,Fangchenggang Entry Exit Inspection and Quarantine Bureau
Yejin Fenxi/Metallurgical Analysis | Year: 2011
The chemical valence of manganese in manganese ore sample was studied. It was found that, the chemical valence of manganese in singly-ignited sample was the same to Mn3O4 and similar to MnO in fused piece. Accordingly, the relationship between the determination method of loss on ignition and the chemical valence of manganese in matrix effect correction was identified. A X-ray fluorescence spectrometric determination method of major and minor components in manganese ore was established. The analytical results of this method were in good agreement with the certified values and the mean value of parallel tests of several certified reference materials. The relative standard deviations(RSD, n=7) of main components in manganese ore were smaller than 2%. The RSD of Mn and Fe was 0.20% and 0.16%, respectively, which could meet the determination requirements of components in manganese ore.
Li Z.-G.,Xinjiang Institute of Ecology and Geography |
Li Z.-G.,CAS Wuhan Botanical Garden |
Zhang R.-H.,CAS Wuhan Botanical Garden |
Lai D.-M.,Xinjiang Institute of Ecology and Geography |
And 3 more authors.
Chinese Journal of Applied Ecology | Year: 2012
In April-October, 2009, a field experiment was conducted to study the effects of drip irrigation with plastic mulching(MD) on the net primary productivity(NPP), soil heterotrophic respiration(Rh), and net CO2 exchange flux(NEFCO2) of cotton field ecosystem in Xinjiang, taking the traditional flood irrigation with no mulching(NF) as the control. With the increasing time, the NPP, Rh, and NEFCO2 in treatments MD and NF all presented a trend of increasing first and decreased then. As compared with NF, MD increased the aboveground and belowground biomass and the NPP of cotton, and decreased the Rh. Over the whole growth period, the Rh in treatment MD(214 g C·m-2) was smaller than that in treatment NF(317 g C·m-2), but the NEFCO2 in treatment MD(1030 g C·m-2) was higher than that in treatment NF(649 g C·m-2). Treatment MD could fix the atmospheric CO2 approximately 479 g C·m-2 higher than treatment NF. Drip irrigation with plastic mulching could promote crop productivity while decreasing soil CO2 emission, being an important agricultural measure for the carbon sequestration and emission reduction of cropland ecosystems in arid area.
Liu G.-W.,Fangchenggang Entry Exit Inspection and Quarantine Bureau |
Wang X.-G.,Guangxi University |
Cui D.-S.,China Certification and Inspection Group Guangxi Co. |
Gong F.-Z.,Guangxi University
Yejin Fenxi/Metallurgical Analysis | Year: 2010
The phosphate ore samples were pretreated by microwave digestion technique. The key factors such as acid medium, dosage, and the pressure and time of microwave digestion were investigated. Consequently, a determination method of lead in phosphate ore by flame atomic absorption spec-trometry was established. The results indicated that in four acid mediums(hydrochloric acid, nitric acid, sulfuric acid and aqua regia), the sample dissolving effect in aqua regia was the best. Its proper dosage is 5 mL per grammes. The three-step microwave digestion procedure were adopted with digestion pressure and time: 0.3 Mpa/60 s, 0.5 Mpa/360 s, l.0 Mpa/180 s. Compared with traditional acid solution method, the dissolving time of microwave digestion was short, and the sample dissolution was complete. The detection limit of method was 0.036 μg/mL. The proposed method was applied to the determination of phosphate ore samples. The relative standard deviation(RSD) was 4.1%-6.6%, and the recovery of standard addition was 94%-108%.
Chen Y.-X.,Fangchenggang Entry Exit Inspection and Quarantine Bureau |
Zeng X.-L.,Dionex China Research and Application Center Hangzhou Laboratory |
Li X.-R.,Fangchenggang Entry Exit Inspection and Quarantine Bureau |
Lu Z.-E.,Fangchenggang Entry Exit Inspection and Quarantine Bureau |
Ma L.-F.,Fangchenggang Entry Exit Inspection and Quarantine Bureau
Yejin Fenxi/Metallurgical Analysis | Year: 2012
The anion and cation (F -, Cl -, NO 2 -, Br -, NO 3 -, SO 4 2-, PO 4 3-, Li +, Na +, NH 2 +, K +, Mg 2+ and Ca 2+) in leaching solution of smelting slag were determined by reagent free ion chromatography. The separation conditions of anion: cation exchange column Ion Pac AS19, gradient elution with potassium hydroxide solution, suppressed conductance detection, flow rate of 1 mL/min; separation conditions of cation: anion exchange column Ion Pac CS16, gradient elution with methanesulfonic acid solution, suppressed conductance detection, flow rate of 1.3 mL/min. The relative standard deviations (RSDs) of retention time, peak height and peak area of testing ions within one day were less than 0.35 %, 1.8% and 1.1%, respectively. The RSDs of retention time, peak height and peak area of testing ions in continuous five days were less than 0.78 %, 2.4% and 1.6%, respectively. The concentration of determined ions with its peak area had good linearity (r=0.9990-0.9999). The detection limit was lower than 20 μg/L. The anion and cation in leaching solution of imported scale slag, vanadium slag and manganese-rich slag were determined with recoveries of standard addition in the range 86%-110%.
Tang M.-Q.,Fangchenggang Entry Exit Inspection and Quarantine Bureau |
Li X.-R.,Fangchenggang Entry Exit Inspection and Quarantine Bureau |
Ruan G.-W.,Fangchenggang Entry Exit Inspection and Quarantine Bureau |
Wei Y.-Q.,Fangchenggang Entry Exit Inspection and Quarantine Bureau
Yejin Fenxi/Metallurgical Analysis | Year: 2015
There was no test method for asbestos in oxide scale in China so far. In this paper, after the sample was dispersed with isopropanol and followed by suction filtration onto the glass fiber filter, a method was proposed for determination of chrysotile, crocidolite and amosite in oxide scale by X-ray diffraction absorption base standard correction method. The linearity of calibration curves for determination of chrysotile, crocidolite and amosite was good. The detection limit was 0.004 5%, 0.002 3% and 0.000 65%, and the lower limit of quantitation was 0.014%, 0.0069% and 0.002 0%, respectively. The prepared oxide scale with 0.20% of asbestos was analyzed. The relative standard deviations (RSD, n=10) of determination results were all less than 8%. The proposed method was verified with the oxide scale sample. The determination results of asbestos were consistent with the reference values. The method could meet the detection requirements for trace asbestos in oxide scale with mass fraction of 0.10%-0.50%. ©, 2015, Central Iron and Steel Research Institute. All right reserved.