The Shapolin Mo deposit in Luoning, western Henan Province, is tectonically located at the eastern part of East Qinling molybdenum ore belt in the southern margin of the North China craton. It is a veinlet-disseminated type molybdenite deposit newly discovered in the hypometamorphic rocks of Archean Taihua Group. The research of geological features was carried out in this area. The Re-Os isotopic dating of one quartz vein sample yielded a model age of 126.8±1.7 Ma. This indicates that the Shapoling molybdenum deposit formed mainly in the Yanshanian, the same as Jinduicheng and Leimengou Mo deposits. The content of Re isotope also shows its material mainly derived from upper mantle. Considering the complication of formation mechanism of the Shapoling molybdenum deposit, further research, especially deep drilling, is needed. It is of great significance to verify the existence of deep-concealed porphyry bodies and porphyry-type Mo ore field with large reserves and the potential of prospecting.

Poly(vinylidene fluoride) (PVDF) membranes were prepared by immersion precipitation method at different coagulation bath temperatures. Effects of coagulation bath temperature on the morphology and crystal structure of PVDF membranes were Studied. The phase diagram of PVDF/DMAc/H2O ternary system was divided into three regions: one phase region, liquid-liquid two phase region and gelation region. Binodal line and spinodal line of phase inversion were calculated based on the thermodynamics equations of membrane formation, and the gel phase boundaries of the systems at 25 and 60 degrees C were determined via cloud point measurement. Based on the phase diagram analysis and experiment results, it Was found that gelation is the dominate membrane formation mechanism at low temperature, but the bicontinuous structure of the formed membrane at 60 degrees C is attribute to spinodal decomposition.Moreover, the thermal behavior and crystal structure of membranes prepared using different coagulation bath temperatures were examined by differential scanning calorimetry (DSC) and wide angle X-ray diffusion (WAXD). The results shows that the PVDF membrane precipitated at 60 degrees C had a typical "alpha" form crystal structure. While at 15 degrees C, the PVDF crystallites are a mixture of "alpha" and "beta" form crystal structure. The crystallization degree of the prepared membrane has not increased with the coagulation bath temperature decreasing.

Effects of coagulation bath temperature on the membrane formation mechanism and the morphologies of the formed membranes were studied. The binodal and spinodal lines in the phase diagrams of water/DMAc/Poly(vinylidene fluoride) (PVDF) were calculated based on the thermodynamics equations of membrane formation, and the gel phase boundaries of the systems at 25 degrees C and 60 degrees C were determined via cloud point measurement. The obtained ternary phase diagrams of water/DMAc/PVDF contain three regions: the one-phase region, the liquid-liquid two-phase region, and the gel region. In the phase diagrams, the liquid-liquid demixing line (binodal) is located inside the gelation line. At low temperature, there exists a wide region between gelation line and binodal line. Gelation Could occur in the absence of liquid-liquid demixing, and becomes the dominant membrane formation mechanism. At high temperatures (60 degrees C), however, the gelation line approaches the binodal line, which results in a much smaller gelation zone. The kinetics of the solvent out-flux and water influx were enhanced, liquid-liquid demixing is the dominant mechanism. The membrane formation mechanisms at different temperature were confirmed by the light transmission measurements during membrane forming process and the morphologies of the membranes examined by SEM imaging. (C) 2008 Wiley Periodicals, Inc.

A rapid and accurate method has been developed for the determination of boron in serum, plasma and urine by inductively coupled plasma mass spectrometry. The memory effects of B were examined using different diluents/rinse solutions, including water, nitric acid, Triton X-100, ammonia and mannitol in water, in nitric acid and in ammonia. A combination of ammonia with mannitol, as both diluent and flush solution, gave the best precision, the minimum memory effect and the lowest background. A sample dilution of 20-fold was simply made for serum and plasma and 100-fold for urine for determination with a single calibration curve. Beryllium was employed as the internal standard to control matrix effects and to compensate for possible fluctuation and instrument drift. The isotope B-10(+) was utilised to avoid spectral overlap by the intense C-12(+) isotope. The final solution of blank, standards and samples contained 0.25% w/v mannitol, 0.1 M ammonia and 20 ng ml(-1) of Be. Six samples, including human and horse serum, human and horse plasma, and human urine, were analysed to test the reliability of the method. A limit of detection (3 sigma) of 0.015 ng ml(-1) was obtained and the recoveries of spiked boron (two spiking levels for each matrix) from the selected samples ranged from 98% to 104%. Much higher concentrations of B in urine (approximate to 1 mu g ml(-1)) were found compared to those in serum and plasma samples (32.8-61.1 ng ml(-1)).

Five sample digestion procedures were evaluated for the determination of Al, B, Ca, Cu, Fe, K, Mg, Mn, Na, P, S, Sr, and Zn in food samples by inductively coupled plasma atomic emission spectrometry. The 5 procedures include dry ashing at 500 degrees C, wet digestion with HNO3-HClO4, microwave digestion with HNO3, microwave digestion with HNO3-H2O2, and microwave digestion with HNO3-H2O2-HF. For microwave digestion with HNO3-H2O2-HF, silicon (IV) oxide was used to eliminate the excess HF, making it possible to determine total Al, B, and other common elements accurately and simultaneously. Seven National Institute of Standards and Technology standard reference materials (SRMs) were analyzed to compare the recovery of 13 elements with above digestion procedures. The results demonstrated that the microwave digestion procedure with HNO3-H2O2-HF yielded the best recoveries for all 13 elements in the selected SRMs. The determined concentrations of most elements were close for all 3 microwave digestion procedures with the exception of Al in oyster tissue, bovine liver, and spinach. Notably, the wet digestion with HNO3-HClO4 is the simplest and the most effective procedure for the selected elements except Al and B. Although there are several concerns with the dry ashing procedure, it might be a preferable procedure for those analyses where only nonvolatile elements are to be determined and the concentrations of the elements are low.

A method is described in which total soil boron (B) was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The method is based on microwave-assisted digestion of soil samples with nitric acid (HNO3), hydrofluoric acid (HF) and hydrogen peroxide (H2O2). Excess HF was eliminated by adding silicon (IV) oxide (SiO2). The B 208.959 nm line was chosen as the analytical line to avoid the spectral interferences of iron (Fe). A detection limit of 0.0045 mg L-1 was obtained with the selected analytical line under the optimized operating conditions. Four National institute of Standards and Technology (NIST) standard reference materials (three soils and one river sediment) and four different type of practical soils were analyzed to test the reliability of the method. The total B concentration in selected samples ranged from 19 to 76 mg kg(-1). The excellent recoveries of the spike (98.5-101%) indicate that the proposed procedure is effective and feasible for the determination of total B in soils.

A sample preparation procedure employing microwave digestion procedure is described for the determination of total aluminum in seafood and meat samples by inductively coupled plasma atomic emission spectrometry (ICP-AES). Lyophilized samples were first digested in closed vessels with HNO3 and HF. An additional digestion then proceeded in open vessels with H2O2. H3BO3 was employed to eliminate excess HF. Matrix effects of Ca, K, Mg, and Na, acid effects of HNO3, and possible spectral interferences were investigated. The influences of amount of HF on analytical results were observed. The recoveries of spike (95.2-97.6%) and the analyses of NIST standard reference materials 1566a (oyster tissues) and 1577b (bovine liver) demonstrated the reliability of the method. Twelve representative seafood and meat samples were analyzed, and the analytical results were compared with those obtained with HNO3-HClO4 digestion on a hot plate and with HNO3-H2O2 microwave digestion. It was shown that the digestion without the addition of HF was incomplete for the determination of total Al.

Determinations of boron in animal tissues were performed by inductively coupled plasma atomic emission spectrometry (ICP-AES) with an ultrasonic nebulizer. The method is based on the microwave digestion of tissues with HNO 3 –H 2 O 2 and the use of mannitol as a modifier. It was found that mannitol can significantly enhance the analytical sensitivity, improve the precision and minimize the memory effect for the determination of boron. Acid effect and matrix effects were controlled by using the Be I 234.861 nm line as the internal standard. Six animal tissue samples, including two NIST standard reference materials (Oyster Tissue and Bovine Liver), were analyzed to test the reliability of the method. A limit of detection (3 σ ) of 0.7 µg l -1 and recoveries of added boron from selected matrices between 95.0 and 100.2% were obtained.

A microwave digestion procedure was developed for determining aluminum and boron and 13 other elements in plant tissues by inductively coupled plasma atomic emission spectrometry (ICP-AES). The sample (0.5 g) was digested in a closed Teflon vessel with 10 mL concentrated nitric acid and 3 mL hydrofluoric acid, and further digested in an open Teflon vessel with 5 mt hydrogen peroxide. Excess hydrofluoric acid was eliminated by adding 0.2 g silicon (IV) oxide. Four National Institute of Standards and Technology standard reference materials (apple leaves, peach leaves, tomato leaves, and pine needles) were analyzed to test the reliability of the method. The excellent recoveries indicate that the proposed procedure is simple and effective for determination of Al, B, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, P, S, Sr, and Zn in plants.

An ultrasonic nebulization-inductively coupled plasma (ICP) atomic emission spectrometry procedure was developed to determine boron in plants and plant-derived foods. Samples were ashed at 550 degrees C for 4 h, and the resulting ash was dissolved into a mannitol-nitric acid solution to form a boron-mannitol complex. Solutions were directly nebulized into ICP by an ultrasonic nebulizer. The memory effect-the main drawback for determining boron with the ultrasonic nebulizer-was minimized with addition of mannitol. Two National Institute of Standards and Technology (NIST) standard reference materials (SRM 1515 apple leaves and SRM 1547 peach leaves) and 25 food and plant materials spiked with NIST SRM 1515 were analyzed to verify method accuracy. Boron contents found in NIST standard samples were in excellent agreement with certified values. A detection limit (2 sigma) of 0.5 mu g/L and typical recoveries of 93 to 106% from spiked selected samples were obtained.

As compared with the economical development of the world, Asia and Pacific region is full of promise, so do in the field of paint industries. The production of paint industries in this region is increased for fourfold in comparison with 1975. The annual increasing rate of paint production in this region is average 4.6%, and is predicted over 5% in 1997-1998.