There is a growing public concern over the potential accumulation of heavy metals in agricultural soils in China owing to rapid urban and industrial development and increasing reliance on agrochemicals in the last several decades. Excessive accumulation of heavy metals in agricultural soils may not only result in environmental contamination, but elevated heavy metal uptake by crops may also affect food quality and safety. The present study is aimed at studying heavy metal concentrations of crop, paddy and natural soils in the Pearl River Delta, one of the most developed regions in China. In addition, some selected soil samples were analyzed for chemical partitioning of Co, Cu, Pb and Zn.The Pb isotopic composition of the extracted solutions was also determined. The analytical results indicated that the crop, paddy and natural soils in many sampling sites were enriched with Cd and Pb. Furthermore, heavy metal enrichment was most significant in the crop soils, which might be attributed to the use of agrochemicals.

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The shape and shift of Raman peak of solid organics prove to be capable of revealing atomic and molecular level vibration information of aromatic ring structure and its relationship with sample maturation. Raman "D" peaks and "G" peaks of a series of continuously maturated coal samples were measured, and the inter-peak intervals (GD) and peak height ratios (Dh/Gh) were derived and correlated with the vitrinite reflectance (vR o %) of standard coal samples. As a result, two formulae were established by using the two Raman indices for calculation of Raman reflectance (RmcR o %), which is equivalent to vitrinite reflectance. The formula for calculating Raman reflectance indicative of organic maturation using Raman shift inter-peak interval (GD) is RmcR o %= 0.0537 d(GD)-11.21, which is mainly applicable to matured to highly matured carbonized samples of solid organics; The formula for calculating Raman reflectance indicative of organic maturation using Raman peak height ratio (Dh/Gh) is RmcR o %= 1.1659 h (Dh/Gh)+2.7588, which is mainly applicable to carbonized samples of solid organics that are over matured or going to be turned into granulated graphite. Preliminary applications indicate that Raman reflectance "RmcR o %" calculated based on results of Raman spectral analysis of solid organics can be used to characterize sample maturation at molecular level, so enjoying extensive prospects in geological applications. In petroleum geology and coal petrography, vitrinite reflectance (vR o %) is a generally universal index gauging maturation of hydrocarbon source rocks and coals. However, highly matured to over-matured samples would show extensive variations in vitrinite reflectance due to considerable inhomogeneity, which would affect accurate assessment of sample maturation. Recently, peak D and peak G in Raman scattering of carbon nanotubes and natural solid organics seem to reflect not only structures and performance of carbon nanotubes but also thermal evolution of carboniferous solid organics in geological samples, and temperature and pressure conditions for experimental samples, so attracting extensive attention from the academic communities in the 7] reported the relationships between Raman inter-peak interval (D-G) and peak height ratio (D/G) of pyrolytic products of bitumite and kerogen and maturation of samples, or the temperature and pressure conditions for experimental samples. These authors concluded that

Among various artificial antibodies, epitope imprinted polymer has been paid increasingly attention. To modulate the "adsorption and release" behavior by environment stimuli, N-isopropylacrylamide, was adopted to fabricate the thermoresponsive epitope imprinted sites. The prepared imprinted materials could adsorb 46.6 mg/g of target protein with the imprinting factor of 4.0. The template utilization efficiency could reach as high as 8.21%. More importantly, in the real sample, the materials could controllably capture the target protein from the human plasma at 45 °C and release it at 4 °C, which demonstrated the "on-demand" application potentials of such materials in the biomolecule recognition field.

A novel clickable periodic mesoporous organosilica monolith with the surface area up to 1707 m(2) g(-1) was in situ synthesized in the capillary by the one-step condensation of the organobridged-bonded alkoxysilane precursor bis(triethoxysilyl)ethylene. With Si-C bonds in the skeleton, the monolith possesses excellent chemical and mechanical stability. With vinyl groups highly loaded and homogeneously distributed throughout the structure, the monolith can be readily functionalized with functional groups by effective thiol-ene "click" chemistry reaction. Herein, with "click" modification of C18, the obtained monolith was successfully applied for capillary liquid chromatographic separation of small molecules and proteins. The column efficiency could reach 148,000 N/m, higher than most reported hybrid monoliths. Moreover, intact proteins could be separated well with good reproducibility, even after the monolithic column was exposed by basic mobile phase (pH 10.0) overnight, demonstrating the great promising of such monolith for capillary chromatographic separation.

The influence of magnesium on the phase transformation and mechanical properties has been investigated by means of dilatometric and microstructural analysis in low carbon microalloyed steel. The thermal simulation experiments were performed on a Gleeble-3800 system equipped with a high-speed deformation dilatometer. The results reveal that, by adding with Mg, the pearlite transformation is delayed, and the pearlite has a scattered distribution even at low cooling rates from 0.1 to 0.5 K/s. It also shows that Mg tends to promote the bainite transformation as a result of the formation of acicular ferrite and granular bainite. Acicular ferrite is attributed to the change of dominant oxide inclusions from inert Al 2 O 3 , to xMgO Á Al 2 O 3 , which serves as an effective nucleant for acicular ferrite. Moreover, bainitic structure obtained by the addition of Mg into the molten steel exhibits the remarkable improvement of toughness and tensile properties.

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Monodispersed silica spheres with solid core and fibrous shell were successfully synthesized using a biphase reaction. Both the thickness and the pore size of the fibrous shell could be finely tuned by changing the stirring rate during synthesis. When stirring was adjusted from 0 to 800 rpm, the thickness of the shell could be tuned from 13 to 67 nm and the pore size from 5 to 16 nm. By continuously adjusting the stirring rate, fibrous shells with hierarchical pore structure ranged from 10 to 28 nm and thickness up to 200 nm could be obtained in one pot. We demonstrate that fibrous shells with controllable thickness and pore size could be coated on silica cores with diameters from 0.5 to 3 μm while maintaining the monodispersity of the particles. As a result of the unique fibrous structure, the BET surface area could reach ∼233 m(2) g(-1) even though the shell thickness was less than 150 nm. The core-shell particles were modified with C18, packed, and then used in high-performance liquid chromatography (HPLC) separation, showing separation performance as high as 2.25 × 10(5) plates m(-1) for naphthalene and back pressure as low as 5.8 MPa. These silica microspheres with fibrous shells are expected to have great potential for practical applications in HPLC.