铽－甲基吲哚乙酰丙酮三元配合物发光过程研究

测定和分析了ＲＥ．Ｌ１．Ｌ２（ＲＥ＝Ｔｂ（Ⅲ）、Ｇｄ（Ⅲ），Ｌ１＝３Ｍ（３甲基吲哚－１－乙酰基丙酮），Ｌ２＝ＴＰＰＯ、Ｐｈｅｎ、Ｄｉｐｙ）三元配合物的荧光光谱、磷光光谱、磷光寿命及变温荧光光谱等．讨论了Ｔｂ（Ⅲ）与配体之间的能级匹配和Ｌ１与Ｌ２的三重态之间传能的问题，说明了影响这些三元配合物荧光效率的主要因素及其发光过程．     

Polyaniline nanofibers fabricated by electrochemical polymerization: A mechanistic study

Polyaniline (PANI) nanofibers with interconnected network-like structures were electropolymerized on stainless steel substrates by galvanostatic electrolysis. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy (UV-vis) and Fourier transform infrared spectroscopy (FTIR). The results show that PANI and gels (mixtures of oligomer, dopant and aniline) form simultaneously during the electrochemical deposition. The gels play an important role in the formation of PANI nanofibers. The PANI formed in the early stage of polymerization is subject to secondary growth along one dimension, since the nucleation sites are suppressed by the wrapped gels. The dendritic degree of PANI nanofibers is related to dopants, and the order is as follows: PANI-H₃PO₄ > PANI-H₂SO₄ > PANI-HNO₃. No nanofibers are obtained using CH₃COOH as dopants due to the high solubility of PANI-CH₃COOH.     

Potential-dependent structure of the interfacial water on the gold electrode

Doubly tunable sum frequency generation (SFG) spectra demonstrate that the water molecules at gold/electrolyte interface change their orientation with applied potential. At negative potentials, water molecules in the double layer align with their oxygen atom pointing to the solution. As potential became positive to be close to the potential of zero charge (PZC), the SFG signal decreased, suggesting the OH groups of the water molecule are either in random orientation or parallel to the electrode. As potential became more positive than the PZC, the SFG signal increased again with the oxygen-up orientation as same as in the negative potential region, indicating that water molecules interact with the adsorbed sulfate anions. The peak position of the SFG spectra indicates a relatively disordered state of water molecules at the gold electrode surface, in contrast to the previously observed ice-like structure of water at electrolyte/oxide interfaces.     

具有新光学性质的Zn-Zn2SiO4纳米同轴线阵列

采用气相沉积技术在Si衬底上生长了Zn-Zn₂SiO₄芯-壳结构纳米同轴线阵列。根部呈笋状的纳米同轴线,直径约100nm,长度可以超过10μm;同轴线芯直径约50nm、壳层厚约25nm。通过X射线衍射的表征以及能量色散谱的线扫描,确定纳米同轴线的芯为Zn,壳层为Zn₂SiO₄。我们提出了一种新的生长机制,同时也为生长均匀的纳米同轴线提供一种新的技术。观察阴极荧光谱发现,纳米同轴线有三个主要发光带:强度最大的中紫外300nm发光、较弱的可见光区560nm以及红外谱区865nm的发光。对纳米同轴线截面的300nm发光峰观测发现,中紫外发光来源于Zn₂SiO₄壳层。正是这种同轴线的结构,使得其具备特殊的光学性质。     

CH3S CH2SH异化反应的理论研究

利用密度泛函理论(DFT)和从头算(ab initio)研究了CH3S←→CH2SH互异化的反应机理．采用HF、B3LYP、MP2理论水平和中等基组6-31(d)，计算了CH3S、CH2SH及其过渡态的结构参数、谐振频率、零点能(ZPF)、总能量和相对能量，并利用B3LYP／6-31(d)的方法计算了反应的内禀反应坐标(IRC)，给出了分子构型和自旋污染沿反应坐标的变化曲线，以及最小能量曲线(MEP)、绝热能量曲线．此外，利用传统过渡态理论(CTST)研究了该互异化反应的速率常数和平衡常数在200～1000K的变化．     

Synthesis and characterization of poly(ethylene oxide‐co‐ethylene carbonate) macromonomers and their use in the preparation of crosslinked polymer electrolytes

Methacrylate‐functionalized poly(ethylene oxide‐co‐ethylene carbonate) macromonomers were prepared in two steps by the anionic ring‐opening polymerization of ethylene carbonate at 180 °C, with potassium methoxide as the initiator, followed by the reaction of the terminal hydroxyl groups of the polymers with methacryloyl chloride. The molecular weight of the polymer went through a maximum after approximately 45 min of polymerization, and the content of ethylene carbonate units in the polymer decreased with the reaction time. A polymer having a number‐average molecular weight of 2650 g mol^?1 and an ethylene carbonate content of 28 mol % was selected and used to prepare a macromonomer, which was subsequently polymerized by UV irradiation in the presence of different concentrations of lithium bis(trifluoromethanesulfonyl)imide salt. The resulting self‐supportive crosslinked polymer electrolyte membranes reached ionic conductivities of 6.3 × 10^?6 S cm^?1 at 20 °C. The coordination of the lithium ions by both the ether and carbonate oxygens in the polymer structure was indicated by Fourier transform infrared spectroscopy. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2195–2205, 2006     

On the behavior of ECN/RED gateways under a large number of TCP flows: Limit theorems

We consider a discrete-time stochastic model of an ECN/RED gateway where competing TCP sources share the link capacity. As the number of competing flows becomes large, the asymptotic queue behavior (normalized by the number of flows) at the gateway can be described by a simple recursion and the throughput behavior of individual TCP flows becomes asymptotically independent. A Central Limit Theorem complement is also presented, yielding a more accurate characterization of the asymptotic queue size. These results suggest a scalable yet accurate model of this complex large-scale stochastic feedback system, and crisply reveal the sources of queue fluctuations. This work was prepared through collaborative participation in the Communications and Networks Consortium sponsored by the U.S. Army Research Laboratory under the Collaborative Technology Alliance Program, Cooperative Agreement DAAD19-01-2-0011. This work was also supported by the Space and Naval Warfare Systems Center—San Diego under Contract No: N66001-00-C-8063. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Laboratory or the U.S. Government.     

Recent studies on phosphorus-bridging carbonyl derivatives: organophosphorus analogs of aldehydes and ketones

Reactions of disodium tetracarbonylferrate, Na₂Fe(CO)₄, with sterically hindered dialkylaminodichlorophosphines, R₂NPCl₂ (R₂N=diisopropylamino, dicyclohexylamino, and 2,2, 6, 6-tetramethylpiperidino) in diethyl ether lead to the air-stable phosphorus-bridging carbonyl derivatives (R₂NP)₂COFe₂(CO)₆ as the major products. The phosphorus-bridging carbonyl group in (i-Pr₂NP)₂COFe₂(CO)₆ has been found to undergo the following types of reactions: 1)Reduction, 2)Acylation, 3)Extrusion of the carbonyl group. The mechanisms of the reactions have been considered.This work was presented at the Workshop «The Modern Problems of Heteroorganic Chemistry» held on the ship «Nikolai Bauman» during the period May 8–13, 1993.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1858–1867, November, 1993.     

Electron transfer reactions of nickel(III) and nickel(IV) complexes

This review narrates the electron transfer reactions of various nickel(III) and nickel(IV) complexes reported during the period 1981 until today. The reactions have been categorized mainly with respect to the type of nickel complexes. The reactivity of nickel(III) complexes of macrocycles, 2,2′-bipyridyl and 1,10-phenanthroline, peptides and oxime–imine, and of nickel(IV) complexes derived from oxime–imine, oxime and miscellaneous ligands with various organic and inorganic electron donors have been included. Kinetic and mechanistic features associated with such interactions have been duly analyzed. The relevance of Marcus cross-relation equations in the delineation of the electron transfer paths has also been critically discussed.     

基于褐藻酸钠-纳米金复合物作非酶标记的新型电化学免疫传感器的研制

比较了用三碘甲状腺氨酸抗体(T3抗体)、褐藻酸钠(AS)标记T3抗体及褐藻酸钠-纳米金复合物(ASN)标记的T3抗体,在通过免疫反应结合到免疫电极表面后,引起的电极表面微环境发生改变的程度;用Fe(CN)3-/4-6为电化学探针,用循环伏安法获取金电极表面微环境改变的电流信息来检测 T3抗体,检测的线性范围为100～1 600ng·ml-1,检出限为45ng·ml-1.