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Carbon dioxide reforming of methane through dc corona discharge plasma reaction at atmospheric pressure is studied. The results indicate that the conversions of reactants are higher through positive corona than those through negative corona.

Abstract: Reaction of tetrabromoterephthalic acid (H2TBTA) with Co(OAc)2, AgNO3, or Pb(OAc)2 under similar conditions affords three new coordination polymers {[Co(TBTA)(DMF)2(H2O)2](DMF)2} n (1), [Ag(TBTA)0.5] n (2), and [Pb2(TBTA)1.5(OH)(DMF)] n (3). All these complexes have been characterized by elemental analysis, IR, powder X-ray diffraction, and TG-DTA techniques. Single-crystal X-ray diffraction reveals that complex 1 has a 1-D neutral coordination array in which the adjacent CoII centers are bridged by the TBTA spacers, whereas 2 displays a binodal CdCl2-type coordination layer in which the AgI ions and TBTA ligands function as 3- and 6-connected nodes, respectively. In the structure of 3, two types of PbII ions are interconnected via the μ4- and μ5-TBTA ligands as well as the μ3-hydroxyl ions to generate a complicated 3-D penta-nodal coordination framework with (3,4,5)-connectivity. These results clearly suggest that the metal centers with distinct binding tendencies are responsible for the remarkable structural diversity of such crystalline materials. [Copyright &y& Elsevier]

Abstract: Two distinct coordination polymers [Zn(TBTA)(DMF)2(CH3OH)2] n (1) and {[Zn(TBTA)0.5(DMF)(OH)]-(H2O)} n (2) have been prepared from the vapor diffusion reactions of ZnII nitrate with a rigid ligand tetrabromoterephthalic acid (H2TBTA) under different solvent atmospheres. Both complexes have been characterized by elemental analysis, IR, powder X-ray diffraction, and TG-DTA techniques. Single crystal-X-ray diffraction studies reveal that 1 displays a 1-D linear motif with TBTA spacers whereas 2 presents a 2-D kgm network with the aid of hydroxyl spacers and 4-connected TBTA linkers. [Copyright &y& Elsevier]

Abstract: The reactions of 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol (Hpyt) with typical octahedral metal ions (CoII and NiII) under different conditions generate a series of porous coordination polymers with the general formula of {[M(pyt)2(H2O)2]·(solvents)} n . In all these complexes, the versatile pyt anionic ligand behaves as the thioamide isomer with the μ-N py,N oxa binding fashion, as confirmed by the X-ray crystallographic studies. Generally, the pyt linkers connect the metal centers to afford uniform 2-D grid-like host coordination frameworks, which stack in a parallel manner to engender the final 3-D crystalline lattices with 1-D open channels. Especially for CoII, different reactive routes and media lead to the productions of four analogous compounds with the inclusion of varied guest solvates, in one of which unusual water clusters are observed. [Copyright &y& Elsevier]

Polychlorinated biphenyls (PCBs) are highly lipohilic compounds with high metabolic persistence and toxicity. PCBs tend to accumulate in the aquatic food chain and make fish a source of various environmental toxicants to humans. Industries in the Bohai Bay include iron and steel smelting, cement manufacturing and waste incineration, which are potential emission sources of PCBs. In this study, risks and potential effects of PCBs in the Bohai Bay were assessed. Twelve dioxin-like polychlorinated biphenyls (dl-PCBs) and seven indicator PCBs in marine fish samples were analyzed by High Resolution Gas Chromatography/High Resolution Mass Spectrometry (HRGC/HRMS). The concentrations of dl-PCBs in marine fishes ranged from 28.9 pg x g(-1) to 1067.6 pg x g(-1) wet weight. The concentrations of indicator PCBs were between 185.5 pg x g(-1) and 8 371.7 pg x g(-1) wet weight. PCB-118 and PCB-105 were the major congeners of the dl-PCBs congeners, which contributed 41% - 56% and 15% - 21%, respectively. The predominant indicator PCBs were PCB-153 and PCB-138, which contributed 27% and 22%, respectively. The concentrations of dl-PCBs and indicator PCBs were relatively low as compared with those in other studies.

A new method to determine Chinese traditional medicine activity eliminating superoxide anion radical by kinetic spectrophotometry was developed. It is shown that the optimum determination condition may be obtained when wavelength is 520 nm, the concentration of enzyme is 4 x 10(-3) microg x mL(-1), the reaction time is between 2-7 min. Vitamin C activity eliminating superoxide anion radical was determined under the condition, and the results were identical with literature. The method is used to determine IC50 of Cortex Magnoliae Officinalis and Cortex Eucommia, and they are 7.580 and 323.800 mg x L(-1) respectively.

Benzoic acid with weak fluorescence may react on .OH, and products with intense fluorescence are made. Extractives of Chinese traditional medicine may eliminate .OH in solution, and make amounts of the products to reduce. Then, increase level of fluorescence of products in solution will be lowered. Based on this principle, a new method is developed to determine eliminating ratio of Chinese traditional medicine for .OH. It is shown that productivity of .OH tends to saturation when H2O2 is shown more than 20 min by 280 nm UV light; .OH may react on benzoic acid completely when molar ratio of H2O2 and benzoic acid is 30:1; linear response range of products fluorescence is 2.2-80 mmol.L-1 with concentration of H2O2. IC50 of elimination .OH with magnoliae and eucommia are 1.025 and 515.3 mg.L-1 respectively. There are no remarkable difference between these results and that of spectrophotometry.