[en] Linear poly(NIPAAm-co-X), with X being AAc or 4-VP, was synthesized by means of γ radiation induced polymerization in tetrahydrofuran (THF). The binary copolymers obtained are possessed of water-soluble, temperature sensitivity. It was also found that raising pH leads to a higher LCST when X is AAc. Prepared copolymers were used to concentrate metal ions, such as UO₂²⁺ RE³⁺ and Cr(VI) in dilute aqueous solution, which showed obvious concentration effect. The conditions of ion concentration were given and the mechanism was discussed preliminary

[en] A nuclide migration device called RADMIG, which can simulate the high level radioactive waste (HLW) repository environments, was designed and manufactured for further suitability evaluation of Gaomiaozi bentonite as the buffer/backfill materials of a HLW repository in China through adsorption and diffusion experiments. It also can be used for granite, the host-rock of the HLW repository in China. The design parameters are: pressure: 1-5.0 MPa; temperature: ambient ∼100 degree C; Eh: ≤-200 mV. The blank test results show that RADMIG can work steadily under any environments in the range of design parameters. And the migration experiments are in progress. (author)

[en] A nuclide migration device called RADMIG, which can simulate the high level radioactive waste (HLW) repository environments, was designed and manufactured for further suitability evaluation of Gaomiaozi bentonite as the buffer/backfill materials of a HLW repository in China through adsorption and diffusion experiments. It also can be used for granite, the host-rock of the HLW repository in China. The design parameters are: pressure: 1-5.0 MPa; temperature: ambient-100 degree C; Eh: ≤-200 mv. The blank test results show that RADMIG can work steadily under any environments in the range of design parameters. And the migration experiments are in progress

[en] A nuclide migration device, RADMIG, which simulates the HLW repository environment, was designed and manufactured. This device was for investigation on migration of radionuclides in/ on buffer/backfill materials and host-rock under the simulated HLW environment, and further evaluation on the possibility of the Gaomiaozi bentonite, Inner Mongolia, as the buffer/backfill material of China HLW repository. The design parameters: pressure: 0-5.0 MPa; temperature: ambient ∼100 degree C; Eh≤-200 mV. The test results show that RADMIG can work steadily under any environment in the range of design parameters. (author)

[en] Engineering barrier for HLW repository is composed of vitrified waste, canister and buffer/backfill material. Assessment of the applicability of metal as candidate materials of canister for HLW has been conducted in some countries.. Many bronze relics in Xizhou Dynasty, China, dated from more than 3000 years ago, have been preserved perfectly. The study on the corrosion of the bronze relics would contribute to the material selection and design of canister for HLW. The corrosion products of ancient bronzes consist of copper carbonate hydrate, lead carbonate, copper oxides etc. The corrosion mechanism of the substrate were mainly characterized by electrochemical corrosion, whereas the corrosion mechanism of surface layers was characterized by direct chemical corrosion and electrochemical corrosion. (author)

No abstract available

[en] In 2001, nitrate concentrations in water from wells in Shijiazhuang City, China ranged from 15 to about 160 mg/L as nitrate, with a median concentration of 50 mg/L. Agricultural return waters from lands irrigated with sewage or groundwater are believed to be the source of increasing nitrate, chloride, sulphate, and dissolved solids concentrations. Recharge rates estimated from chemical and tritium data are about 130 mm/y for non-irrigated agricultural land and exceed 200 mm/y for irrigated land. Nitrate concentrations in pore water in the unsaturated zone were as high as 930 mg/L. As much as 350 kg/ha of nitrogen is stored in the upper 18 m of the unsaturated zone beneath a groundwater irrigated site. As much as 780 kg/ha of nitrogen could be stored in thicker unsaturated zones within the study area and nitrogen storage beneath sewage irrigated sites is even probably greater. About 60% of the nitrate stored in the unsaturated zone is in the form of nitrate and 36% is in the form of ammonia. Denitrification in near-saturated fine-grained layers reduces the concentration of nitrate in with depth and at 18 m below land surface 60% of the nitrogen is in the form of ammonia. The δ¹⁵N composition of water from sampled wells ranged from 2.2 to 11.7 per mille, with median value of 6.1 per mille. Water from wells in the urban area had the highest average δ¹⁵N compositions with progressively lower values in the village and farmland areas. δ¹⁵N values in surficial soils averaged 1.0 per mille in natural sites, 9.5 per mille in sewage and manure amended sites, and 7.3 per mille in the chemically fertilized sites. Most δ¹⁵N values in water from wells are in the range of compositions expected from sewage and manure sources of nitrogen-with some denitrification, although extensive denitrification of nitrogen from chemical fertilizers also could produce observed δ¹⁵N values. (author)

[en] Chemical-looping combustion (CLC), which has the characteristic of greenhouse gas CO₂ inherent separation, is a novel combustion technology. In this study, CLC experiments of methane using CaSO₄ oxygen carrier with lime addition were carried out in a batched fluidized bed reactor, where the sample was exposed to alternate oxidizing and reducing conditions. The influences of temperature, calcium-to-sulphur ratio and lime particle size on the conversion of CaSO₄ and sulfur capture were investigated and a suitable operation condition was determined. Under the optimal operation condition, a multi-cycle test was performed to evaluate the cyclic redox behavior of the lime promoted CaSO₄ sample. X-ray diffraction and a field emission scanning electron microscope were used to characterize the phase and surface morphology of the samples used. The results show that the addition of lime could improve the conversion rate of CaSO₄ and the capture efficiency of sulfur-containing gases. The operation conditions of calcium to-sulfur ratio 0.8, lime particle size of 180-250 μm and operation temperature of 900 °C turned out to be the optimal conditions. Besides, the average desulphurization rate of lime was up to 78.77% during the cyclic test. (author)

[en] It has been reported that: 'direct analysis of thin layer chromatography (TLC) plates with secondary ion mass spectrometry (SIMS) yields no satisfactory results' (J. Chromatogr. A 1084 (2005) 113-118). While this statement appears to be true in general, we have identified two important classes of compounds, organic halides and amines, that appear to yield to such direct analyses. For example, five organic halides with diverse structures were eluted on normal phase TLC plates. In all cases the halide signals in the negative ion time-of-flight secondary ion mass spectrometry (ToF-SIMS) spectra were notably stronger than the background signals. Similarly, a series of five organic amines with diverse structures were directly analyzed by positive ion ToF-SIMS. In all but one of the spectra characteristic, and sometimes even quasi-molecular ions, were observed. Most likely, the good halide ion yields are largely a function of the electronegativity of the halogens. We also propose that direct analysis of amines on normal phase silica gel is facilitated by the acidity, i.e., proton donation, of surface silanol groups

[en] Laser-activation-modification of semiconductor surfaces (LAMSS) was carried out on silicon with a series of 1-alkenes. These laser spots were studied by time of flight secondary ion mass spectrometry (ToF-SIMS). The resulting spectra were analyzed using the multivariate curve resolution (MCR) method within the Automated eXpert Spectral Image Analysis (AXSIA) toolkit, and also by MCR and cluster analysis using commercially available toolboxes for Matlab: the PLS_Toolbox and the MIA_Toolbox, respectively. AXSIA based MCR generally finds three components for the spectral images: one for the background and two for the laser-activated spots, for both the positive and negative ion images. The negative ion component spectra from the spots show increased carbon and hydrogen signals compared to oxygen. They also show reduced chlorine and fluorine (contamination) peaks. In order to compare AXSIA-MCR results from different images, the AXSIA component spectra of different spots were further analyzed by principal components analysis (PCA). PCA of all of the negative ion components shows that component 1 is chemically distinct from components 2 and 3. PCA of all of the positive ion components yields the same result. The loadings plots of this PCA analysis confirm that component 1 generally contains fragments expected from the substrate, while components 2 and 3 contain fragments expected from an overlayer composed of alkyl chains in the spots. A comparison of the two MCR analyses suggests that roughly the same information can be obtained from AXSIA, which is not commercially available, and the PLS_Toolbox. Cluster analysis of the data also clearly separates the spots from the backgrounds. A key finding from these analyses is that the degree of surface functionalization in a LAMSS spot appears to decrease radially from the center of the spot. Finally, a comparison of atomic force microscopy (AFM) of the spots versus the AXSIA analysis of the ToF-SIMS data produced another important result, which is that the surface morphology is only weakly correlated with the LAMSS chemistry