An interesting T4（2）5（2） water tape formed by fused cyclic water pentamers and tetramer was self-assembled in a new inorganic host [Ni（L）（phen）2]·5H2O （L = L-cysteic acid） and characterized by X-ray dif...An interesting T4（2）5（2） water tape formed by fused cyclic water pentamers and tetramer was self-assembled in a new inorganic host [Ni（L）（phen）2]·5H2O （L = L-cysteic acid） and characterized by X-ray diffraction. Each [Ni（L）（phen）2] molecule crystallizes with five water molecules with a molecular formula of [Ni（L）（phen）2]·5H2O. The T4（2）5（2） water tape and [Ni（L）（phen）2] molecules assemble into a network of water tapes sandwiched between [Ni（L）- （phen）2] tapes. The network is stabilized by π-π stacking between [Ni（L）（phen）2] molecules and three types of hydrogen-bonding interactions between [Ni（L）（phen）2] molecules, water molecules, and water and [Ni（L）（phen）2] molecules.展开更多
More and more attention is being focused on saline water utilization in irrigation due to the shortage of fresh water to agriculture in many regions. For purpose of reducing the risks of using of saline water for irri...More and more attention is being focused on saline water utilization in irrigation due to the shortage of fresh water to agriculture in many regions. For purpose of reducing the risks of using of saline water for irrigation, the mechanism of soil moisture and salinity distribution and transport should be well understood for developing optimum management strategies. In this paper, field experiments were carried out at Junggar Basin, China, to study the effects of drip irrigation water quality and drip tape arrangement on distribution of soil salinity and soil moisture. Six treatments were designed, including two drip tape arrangement modes and three irrigation water concentration levels （0.24, 4.68, and 7.42 dS m^-l）. Results showed that, soil moisture content （SMC） directly beneath the drip tape in all treatments kept a relatively high value about 18% before boll opening stage; the SMC in the narrow strip in single tape arrangement （Ms） plot was obviously lower than that in the double tapes arrangement （Md） plot, indicating that less sufficient water was supplied under the same condition of irrigation depth, but there was no significant reduction in yield. Mulching had not significant influence on salt accumulation but the drip tape arrangement, under the same condition of irrigation water depth and quality, compared with Md, Ms reduced salt accumulation in root zone and brought about relatively high cotton yield.展开更多
A new mixed-ligand Zn（II） complex, [Zn（4,4′-bipy）2（H2O）4]-2ANS·6H2O （1, 4,4′- bipy = 4,4′-bipyridine, HANS = 2-aminonaphthalene-l-sulfonic acid）, has been isolated and structurally characterized by sin...A new mixed-ligand Zn（II） complex, [Zn（4,4′-bipy）2（H2O）4]-2ANS·6H2O （1, 4,4′- bipy = 4,4′-bipyridine, HANS = 2-aminonaphthalene-l-sulfonic acid）, has been isolated and structurally characterized by single-crystal X-ray diffwaction, FT-IR spectrum, TG and elemental analysis. It crystallizes in the monoclinic system, space group P2 1/c with a = 12.4852（8）, b = 18.3163（12）, c = 10.9707（7） A, β = 114.2600（10）°, V= 2287.3（3） A3, Dc = 1.455 g/cm3, Mr = 1002.37, Z = 2, F（000） = 1048,μ = 0.704 mm＂1, the final R = 0.0408 and wR = 0.962 for 4029 observed reflections with I 〉 2σ（I）. Interestingly, an unusual one-dimensional （1D） water tape with cyclic tetrameric water clusters can be observed in 1, which are further trapped via Zn-O coordination bonds exhibiting a 2D Zn（Ⅱ）-water layer. These 2D Zn（Ⅱ）-water layers are stacked together into a 3D interdigitated supramolecular architecture via weak π…π interactions, in which free ANS anions are tightly filled by hydrogen-bonding interactions. Thus, π…π and classical hydrogen-bonding interactions are fotmd as main driving forces to stabilize the 2D Zn（Ⅱ）-water layers.展开更多
In hydrochloric acid medium,a highly sensitive fluorescence quenching method was developed for the determination of ClO2,based on its oxidation of I to I3 by ClO2 and the further reation of I3 with rhodamine 6G to for...In hydrochloric acid medium,a highly sensitive fluorescence quenching method was developed for the determination of ClO2,based on its oxidation of I to I3 by ClO2 and the further reation of I3 with rhodamine 6G to form the ion-association complex.The detection Iimit is 0.8 μg/L.The linear range of calibration curve is 0-80 μg/L.It has been applied to the determination of trace ClO2 in tap water with satisfactory results.展开更多
基金supported by the Natural Science Foundation of Guangxi Province (No. 2010GXNSFD013017)
文摘An interesting T4（2）5（2） water tape formed by fused cyclic water pentamers and tetramer was self-assembled in a new inorganic host [Ni（L）（phen）2]·5H2O （L = L-cysteic acid） and characterized by X-ray diffraction. Each [Ni（L）（phen）2] molecule crystallizes with five water molecules with a molecular formula of [Ni（L）（phen）2]·5H2O. The T4（2）5（2） water tape and [Ni（L）（phen）2] molecules assemble into a network of water tapes sandwiched between [Ni（L）- （phen）2] tapes. The network is stabilized by π-π stacking between [Ni（L）（phen）2] molecules and three types of hydrogen-bonding interactions between [Ni（L）（phen）2] molecules, water molecules, and water and [Ni（L）（phen）2] molecules.
基金supported by the National Natural Science Foundation of China(40771097)the Special Fund of Industrial(Agriculture)Research for Public Welfare of China(200903001)
文摘More and more attention is being focused on saline water utilization in irrigation due to the shortage of fresh water to agriculture in many regions. For purpose of reducing the risks of using of saline water for irrigation, the mechanism of soil moisture and salinity distribution and transport should be well understood for developing optimum management strategies. In this paper, field experiments were carried out at Junggar Basin, China, to study the effects of drip irrigation water quality and drip tape arrangement on distribution of soil salinity and soil moisture. Six treatments were designed, including two drip tape arrangement modes and three irrigation water concentration levels （0.24, 4.68, and 7.42 dS m^-l）. Results showed that, soil moisture content （SMC） directly beneath the drip tape in all treatments kept a relatively high value about 18% before boll opening stage; the SMC in the narrow strip in single tape arrangement （Ms） plot was obviously lower than that in the double tapes arrangement （Md） plot, indicating that less sufficient water was supplied under the same condition of irrigation depth, but there was no significant reduction in yield. Mulching had not significant influence on salt accumulation but the drip tape arrangement, under the same condition of irrigation water depth and quality, compared with Md, Ms reduced salt accumulation in root zone and brought about relatively high cotton yield.
基金Supported by the Advanced Project for Young Teachers in Tianjin Normal University
文摘A new mixed-ligand Zn（II） complex, [Zn（4,4′-bipy）2（H2O）4]-2ANS·6H2O （1, 4,4′- bipy = 4,4′-bipyridine, HANS = 2-aminonaphthalene-l-sulfonic acid）, has been isolated and structurally characterized by single-crystal X-ray diffwaction, FT-IR spectrum, TG and elemental analysis. It crystallizes in the monoclinic system, space group P2 1/c with a = 12.4852（8）, b = 18.3163（12）, c = 10.9707（7） A, β = 114.2600（10）°, V= 2287.3（3） A3, Dc = 1.455 g/cm3, Mr = 1002.37, Z = 2, F（000） = 1048,μ = 0.704 mm＂1, the final R = 0.0408 and wR = 0.962 for 4029 observed reflections with I 〉 2σ（I）. Interestingly, an unusual one-dimensional （1D） water tape with cyclic tetrameric water clusters can be observed in 1, which are further trapped via Zn-O coordination bonds exhibiting a 2D Zn（Ⅱ）-water layer. These 2D Zn（Ⅱ）-water layers are stacked together into a 3D interdigitated supramolecular architecture via weak π…π interactions, in which free ANS anions are tightly filled by hydrogen-bonding interactions. Thus, π…π and classical hydrogen-bonding interactions are fotmd as main driving forces to stabilize the 2D Zn（Ⅱ）-water layers.
文摘In hydrochloric acid medium,a highly sensitive fluorescence quenching method was developed for the determination of ClO2,based on its oxidation of I to I3 by ClO2 and the further reation of I3 with rhodamine 6G to form the ion-association complex.The detection Iimit is 0.8 μg/L.The linear range of calibration curve is 0-80 μg/L.It has been applied to the determination of trace ClO2 in tap water with satisfactory results.
