A novel potential-triggered SBA-15/PANI/PSS composite film for selective removal of lead ions from wastewater

In this study, a novel potential-triggered electroactive composite film consisting of mesoporous silica SBA-15, polyaniline (PANI), and polystyrenesulfonate (PSS) was fabricated in an aqueous electrolyte solution via a facile pulse potentiostatic method. The obtained composite film was characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric (TG) analysis, and scanning electron microscopy (SEM). The ion exchange properties were evaluated in a solution containing 0.1 M Pb(NO₃)₂ by using an electrochemical quartz crystal microbalance (EQCM) as well as cyclic voltammetry (CV) method. It was found that the uptake/release of Pb²⁺ ions in/from SBA-15/PANI/PSS composite film was successfully achieved by modulating the redox states of the electroactive composite film, and the composite film exhibited different ion exchange behaviors at different scan rates. Based on these results, the ion exchange mechanism was proposed. Compared with the PANI/PSS composite film, the SBA-15/PANI/PSS composite film had higher adsorption capacity as well as higher selectivity toward Pb²⁺ ions, which should be attributed to the 3D porous morphology of the composite film with more active sites in the mesoporous SBA-15. Remarkably, the film maintained a high stability over 97% even after 500 successive cycles. It is expected that this SBA-15/PANI/PSS composite film can serve as a promising electroactive material for the effective separation of Pb²⁺ ions from wastewater.

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On the limiting factor of impregnation methods for developing Cu/CeO<Subscript>2</Subscript> anodes for solid oxide fuel cells

The efficiency of impregnation methods for making Cu-based solid oxide fuel cells (SOFCs) is qualitatively characterized for the first time through a conformal coating model. It is found that the low-efficiency results from the uneven distribution of Cu instead of the small loading. Most of the Cu deposits form isolated islands, e.g., in a 20.4 vol.% Cu-loaded anode, 81% Cu is isolated from each other. In order to address the limited impregnation efficiency, two different procedures are adopted to fabricate the practical Cu/CeO₂ anodes, namely, simultaneous and sequential impregnation procedures. It is found that CeO₂ works as a solid dispersant, improving the Cu distribution drastically. Compared to the Cu-only anode, more than a threefold improvement of impregnation efficiency is achieved by both methods. The anode made by the sequential impregnation yields the best performance in CH₄ at 700 °C, 170 mW cm^?2, which represents an 18% enhancement over that of the simultaneous impregnation, or 340% over the Cu-only anode. These findings demonstrate that it is of importance to optimize the Cu impregnation to yield a highly active anode, and the sequential impregnation method is a promising procedure to break the efficiency-limiting factor and produce a high-performance anode with minimized fabrication effort.     

Thermo- and pH- dual responsive inorganic-organic hybrid hydrogels with tunable luminescence

A thermo- and pH- dual responsive luminescent hydrogel was successfully constructed by coupling dysprosium-containing polyoxometalates Na₉DyW₁₀O₃₆ (DyW₁₀) with the ABA triblock copolymer, where the B block is PEO and the A block is the thermosensitive poly(methoxydi(ethylene glycol) methacrylate-co-N,N-dimethylaminoethyl methacrylate). The complex hybrid underwent a sol-gel phase transition above the lower critical solution temperature (LCST) of the A block. DyW₁₀ was electrostatically encapsulated into the hydrophobic domain of the A block with enhanced photoluminescence. When temperature cooled down, the luminescence could be restored. By addition of acids to protonate the A block, and emission of DyW₁₀ was simultaneously enhanced. Sensitivity of poly(N,N-dimethy laminoethyl methacrylate) (PDMAEMA) to pH also enabled the emission of DyW₁₀/copolymer hydrogel to be reversibly switched by alternating acid/base treatments.     

用广义交互确认方法选择良好参数进行多元多项式散乱数据自然样条光顺

1．简介多元样条函数在多元逼近中发挥很大作用，已有数量相当多的综合报告和研究论文正式发表，就在1996年6月在法国召开的第三届国际曲线与曲面会议上便有不少多元样条方面的报告，不过总的感觉是仍然缺乏对噪声数据特别是散乱数据的有效光顺方法．李岳生、崔锦泰、关履泰、胡日章等讨论广义调配样条与张量积函数，并用希氏空间样条方法处理多元散乱数据样条插值与光顺，提出多元多项式自然样条，推广了相应一元的结果．我们知道，在样条光顺中有一个如何选择参数的问题，用广义交互确认方法（generalizedcross－validation，以下简称GC…     

Oscillation for systems of nonlinear neutral type parabolic partial functional differential equations

This paper discusses the oscillation of solutions for systems of nonlinear neutral type parabolic partial fuctional differential equations of the form     

吖啶酯标记的化学发光免疫分析优化参数评价

以睾酮-3-羧甲氧基肟-牛血清白蛋白为免疫原,免疫家兔产生抗血清,10-甲基吖啶-9-羧酸[4-(N-睾酮-3-羧甲氧基肟)-氨乙基]苯酯为示踪化合物,采用平衡法建立睾酮化学发光免疫分析,数据用四参数Logistic函数处理。方法学考核标准曲线稳定,R为0.9967;ED50为82.15ng/L;批内和批间CV分别为5.78%和3.3%;平均回收率为107.28%;可测范围为19.3～264.6ng/L,与雌酮、雌二醇、雌三醇和孕酮的交叉反应率均小于1.35%;非特异结合率为9.64%.“桥效应”分析表明同位点、“桥”结构相同亲和力最大.     

Influence of Sulfation on the Catalytic Activity of Ni-ZrO2 for NO Reduction with Propane in Excess Oxygen

Selective catalytic reduction （SCR） of nitric oxide with propane in excess oxygen was investigated on Ni-ZrO2 （NZ） and sulfated Ni-ZrO2 （SNZ）, prepared by coprecipitation from a mixture of nickel nitrate-zirconium oxychloride followed by modifying with （NH4）2SO4. It was found that sulfated Ni-ZrO2 catalyst showed higher activity for the SCR of NO with propane than that of Ni-ZrO2. The structural and surface properties of catalysts were studied by XRD, BET, SEM and FT-IR of pyridine adsorption. The experimental results indicated that the modification of （NH4）2SO4 resulted in the generation of strong BrOnsted and Lewis acid sites and promoted the dispersion of the Ni species, which could lead to higher NO conversion and propane efficiency in NO reduction.     

Selective generation of charge-cependent/independent ion energy distributions from a heated capillary electrospray source

Retarding grid and Fourier transform ion cyclotron resonance (FTICR) mass spectrometry variable trap potential measurements are performed to determine factors that contribute to the kinetic energy distribution of ions formed in an electrospray source that uses a heated capillary for desolvation. The control of ion kinetic energies is achieved by manipulating the skimmer position in the postcapillary expansion and by varying the potential appEed to the skimmer. The selective generation of either charge-dependent or charge-independent ion energy distributions is demonstrated. Charge-dependent energy distributions of electro-sprayed ions are created by sampling ions near the Mach disk of the supersonic expansion and by using a larger diameter skimmer orifice; the FTICR spectra acquired under these conditions exhibit mass-to-charge ratio-dependent mass discrimination determined by the potential used to trap the ions. Charge-independent energies of electrosprayed ions are created by positioning the capillary adjacent to the skimmer to sample thermal ions and by using a smaller skimmer orifice to reduce expansion cooling; under these conditions ion kinetic energy is determined primarily by the skimmer potential and no mass-to-charge ratio-dependence is observed in the selection of optimum FTICR trapping conditions. The ability to select between proteins of different conformation on the basis of kinetic energy differences is demonstrated. For example, a 0.4 V difference in trap potential is observed in the selective trapping of open and closed forms of the +10 charge state of lysozyme. Finally, it is demonstrated that by operating the source under conditions which deliver a beam of ions with charge-independent energies to the cell, it is possible to obtain precursor and product ion signal magnitudes in FTTCR spectra without charge-dependent mass discrimina-tion.     

H3N(CH2)7NH3]8(CH3NH3)2Sn(IV)Sn(II)12I46- a mixed-valent hybrid compound with a uniquely templated defect-perovskite structure

The incorporation of H(3)N(CH(2))(7)NH(3) with CH(3)NH(3)SnI(3) resulted in the formation of a mixed-valent and semiconducting (Eg = 0.84 eV) organic-based perovskite, [H(3)N(CH(2))(7)NH(3)](8)(CH(3)NH(3))(2)Sn(iv)Sn(ii)(12)I(46), with a unique 3D defect-perovskite structure with ordered vacancies at the Sn and I sites.