A modified introduction device and a preconcentration method were developed to enhance the sensitivity of the Hg isotopic analysis method.

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A high concentration of dissolved gaseous mercury (DGM) was detected in post-desulfurized waste seawater, which was discharged from a coal-fired power plant equipped with a seawater desulfurization system and which was located in a coastal area. A large amount of DGM was converted from other forms of mercury during transformation processes, such as photo-reduction. The present study targeted the photo-reduction of mercury and the effects of various environmental parameters on DGM production in the post-desulfurized seawater discharged. The results suggested that the photoreduction of mercury was significantly induced under UV radiation, especially with UVB. The particulate mercury on suspended solids was easily photo-reduced and considered as an important source of DGM. It was confirmed that the suspended solids in postdesulfurized seawater could enhance the reduction process of mercury under UV radiation. The pseudo-firstorder rate constants of DGM production, which were determined through the concentration gradient and trial methods, were 1.39×10 −3 min −1 and 1.45×10 −3 min −1 , respectively. The values showed no significant difference and were both much higher than the reported results, indicating that the photo-reduction of mercury in post-desulfurized seawater deserved more attention. In addition, the initial mercury level was observed when mixing the post-desulfurized seawater with fresh seawater, and this suggested that a significant amount of initial mercury would be produced when the post-desulfurized seawater was discharged into the adjacent sea area and thus becomes another considerable source of DGM.

Variations in the composition of stable isotopes of mercury contained in tissues (root, stem, leaf, and hypocotyl or flower) of three typical mangrove plants (Kandelia candel, Aegiceras corniculata, and Bruguiera gymnorhiza), collected from the mangrove wetland of Jiulong estuary, SE China, were used to investigate the sources and transformation of mercury in the mangrove plants. Tissue samples from the plants were digested and mercury in the solution was pre-concentrated with purge-trap method and then analyzed by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The results showed that the mass dependent fractionation (MDF) of mercury ranged from -2.67 to -0.87 ‰ for δ Hg while the mass independent fractionation (MIF) of mercury isotopes ranged from -0.16 to 0.09 and -0.19 to 0.05 ‰ for ΔHg and ΔHg, respectively, relative to the standard NIST SRM 3133. The ratio of ΔHg/ΔHg was 0.991, indicating that the mercury had been photo-reduced before being accumulated in mangrove plants. Analyses of the data from MIF studies revealed that the major portion of the mercury measured in leaves (∼90 %) originated from the atmosphere while the source of over half of the mercury present in roots was the surficial sediment. This study, the first of its kind investigating the variations in isotopic composition of mercury in the tissues of mangrove plants, could be helpful to identify the source of mercury contamination in mangroves and understand the biogeochemical cycle of mercury in the estuarine mangrove wetlands.

Active samplers for ambient monitoring of trace contaminants in surface water are highly desirable, but their use is often constrained by power supply. Here, we proposed a novel solution by coupling an improved osmotic pump (OP) with a solid-phase extraction (SPE) cartridge to construct a power-free active sampler for organic contaminants. The OP simply consisted of two cylindrical chambers separated by a reverse osmosis membrane. We, for the first time, added ionexchange resins into the OP inlet chamber and successfully constructed OPs with a smooth and constant flow. In the OP-SPE sampler, water was continuously drawn through the SPE cartridge at a constant flow, and time-weighted average concentration over the sampling course may be easily calculated from the amount of target analytes retained on the SPE cartridge and water collected in the sampler. The OP-SPE samplers were deployed in a river to detect herbicides, and the measured concentrations were largely in agreement with the average of 11 daily spot samples. Given that a wide range of SPE cartridges are available for different classes of organic contaminants, this approach is versatile and may find widespread applications for in situ sampling of surface water under different conditions, including poorly accessible locations.

The purpose of this paper is to find the Apple' marketing strategies in Chinese market, one of the most successful smartphone brands in the world. This paper will give the details of Apple marketing strategies in China, a marketing strategy refers to a business's overall game plan for reaching prospective consumers and turning them into customers of their products or services. A marketing strategy contains the company's value proposition, key brand messaging, data on target customer demographics, and other high-level elements. A thorough marketing strategy covers product, price, place, and promotion. The methodology is literature review that the market strategies in China and why Apple can keep the lead in China smartphone market. Apple had use a good market strategy, whether in attracting customers or selling the product.

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