表面电荷转移掺杂石墨烯的研究进展

表面电荷转移掺杂是调制石墨烯电学特性的重要手段。发展高效、稳定的表面电荷转移掺杂剂对于提高石墨烯的电学和光电性能、从而推动其在电子和光电领域中的应用具有重要意义。本文围绕高效与稳定两个方面综述了近年来石墨烯表面电荷转移掺杂剂的研究现状以及掺杂石墨烯在光电器件应用方面的进展。根据掺杂剂的类型，着重介绍了最新发展的高效p型和n型掺杂剂，并概述了稳定掺杂方面的重要研究工作。此外，专门介绍了基于掺杂石墨烯透明电极的高性能光电器件。最后，根据表面电荷转移掺杂研究面临的主要挑战，对其未来的发展方向进行了展望。     

Nitrogen-doped carbon monolith for alkaline supercapacitors and understanding nitrogen-induced redox transitions

A nitrogen-doped porous carbon monolith was synthesized as a pseudo-capacitive electrode for use in alkaline supercapacitors. Ammonia-assisted carbonization was used to dope the surface with nitrogen heteroatoms in a way that replaced carbon atoms but kept the oxygen content constant. Ammonia treatment expanded the micropore size-distributions and increased the specific surface area from 383 m(2) g(-1) to 679 m(2) g(-1). The nitrogen-containing porous carbon material showed a higher capacitance (246 F g(-1)) in comparison with the nitrogen-free one (186 F g(-1)). Ex situ electrochemical spectroscopy was used to investigate the evolution of the nitrogen-containing functional groups on the surface of the N-doped carbon electrodes in a three-electrode cell. In addition, first-principles calculations were explored regarding the electronic structures of different nitrogen groups to determine their relative redox potentials. We proposed possible redox reaction pathways based on the calculated redox affinity of different groups and surface analysis, which involved the reversible attachment/detachment of hydroxy groups between pyridone and pyridine. The oxidation of nitrogen atoms in pyridine was also suggested as a possible reaction pathway.     

A multi-objective joint replenishment inventory model of deteriorated items in a fuzzy environment

In this study, a fuzzy multi-objective joint replenishment inventory model of deteriorating items is developed. The model maximizes the profit and return on inventory investment (ROII) under fuzzy demand and shortage cost constraint. We propose a novel inverse weight fuzzy non-linear programming (IWFNLP) to formulate the fuzzy model. A soft computing, differential evolution (DE) with/without migration operation, is proposed to solve the problem. The performances of the proposed fuzzy method and the conventional fuzzy additive goal programming (FAGP) are compared. We show that the solution derived from the IWFNLP method satisfies the decision maker’s desirable achievement level of the profit objective, ROII objective and shortage cost constraint goal under the desirable possible level of fuzzy demand. It is an effective decision tool since it can really reflect the relative importance of each fuzzy component.     

高效液相色谱-全苯基衍生化β-环糊精短柱分离5种手性β-受体阻滞剂

采用5 cm较短的全苯基异氰酸酯衍生化的β-CD键合硅胶手性柱,在RP-HPLC条件下,对烯丙洛尔、普萘洛尔、美西津、美托洛尔和吲哚心安5种β-受体阻滞剂类药物进行了手性分离的研究。结果表明,除烯丙洛尔外,其它4种药物均在ACN-0.1%TEAA(40∶60,V/V,pH=4.0)的流动相中得到了最佳分离。所制备的短柱具有快速分离的特点,在5 min内实现了上述5对手性药物对映异构体的分离,具有较高的分离效率。针对药物的结构特点,对相关手性分离机理进行了探讨。本方法具有简便快捷、高效及重复性好等特点。     

Compact, Low Threshold Nd^3＋：YVO4 Self-Raman Laser at 1178 nm

A compact low-threshold Raman laser at 1178 nm is experimentally realized by using a diode-end-pumped actively Q-switched Nd^3＋ ：YVO4 self-Raman laser. The threshold is 370mW at a pulse repetition frequency of S kHz. The maximum Raman laser output is 182 m W with the pulse duration smaller than 20 ns at a pulse repetition frequency of 30kHz with 1.8 W incident power. The optical efficiency from the incident power to the Raman laser is 10% and the slope efficiency is 13.5%.     

Forward-backward multiplicity correlations 4.5 A GeV/c ^16O-emulsion interactions

A detailed study of the mechanisms of the emissions of pions and protons in the forward and backward hemispheres in 4.5 A GeV/c oxygen-emulsion interactions has been carried out. The correlations between the multiplicities of secondary charged particles in the backward and forward hemispheres are investigated.     

On the investigation of the preparation of inorganic ionic clusters by laser desorption ionization

CeO(H₂O) _n ⁺ cluster ions, withn as large as 20, are generated by laser desorption ionization of a frozen aqueous solution of CeCl₃,7H₂O. A simple dynamic model developed previously can qualitatively account for experimentally observed threshold behavior, and the time- and fluence-dependence of ion signals.Dedicated to Professor Jiaxi Lu on the occasion of his 80th birthday.     

Sensitization of surfactant on the fluorescent reactions of metals

The effects of different surfactants on the Hf-quercetin, Zr-quercetin, Sn-morin, Mg-oxine-5-sulfonic acid (H₂QS), Zn-H₂QS, Cd-H₂QS and Tb-EDTA-sulfosalicylic acid (SSA) systems were investigated. It was found that the fluorescence intensity of each complex studied is greatly increased in the presence of a suitable surfactant. The optimum conditions for the formation of the ternary complexes involving a surfactant were found, and the compositions of these ternary complexes were established by fluorometry. In the presence or absence of a surfactant, the quantum efficiencies (ϕ) of fluorescent complexes were measured by the relative method, and their molar absorptivities at the excitation wavelength (ϵ_ex) were calculated. It was found that the quantum efficiencies and molar absorptivities of fluorescent complexes were increased to various degrees because of the formation of the ionic associated complexes with fixed compositions, thus leading to greatly increased fluorescence intensity. The function of surfactant micelles and the relation between the molecular structures of surfactants and their effects on the fluorescent reactions were discussed. It is noted that only those surfactants with their aromatic system uncharged or unconnected directly with a charged functional group can sensitize the fluorescent reactions. By making use of the surfactant sensitization it is possible to develop some highly sensitive fluorometries of the metals.     

First total synthesis of louisianin A

The first total synthesis of louisianin A, 4-allyl-6,7-dihydro-1-hydroxycyclopenta[c]pyridin-5-one, is achieved from 2-chloro-4-cyanopyridine 5 via seven steps in an overall 24% yield. The key step is a cyclization-decarboxylation sequence toward the formation of a cyclopentenone ring.     

The role of crystal phase in determining photocatalytic activity of nitrogen doped TiO2

Two series of nitrogen doped TiO(2) samples with different ratios of anatase to rutile phases were prepared by milling the mixture of P25 TiO(2) and C(6)H(12)N(4) in air and gaseous NH(3) atmosphere, respectively. Compared to air, NH(3) atmosphere plays an important role in delaying the crystallite transformation from anatase to rutile in the mechanochemical reaction of TiO(2) and C(6)H(12)N(4). In contrast to the previously reported results for pure TiO(2), it is found that nitrogen doped TiO(2) with higher content of rutile phase demonstrates higher photocatalytic activity in photodegrading pollutant Rhodamine B under both UV light and visible light irradiation (lambda>420 nm), and the amount of the surface-adsorbed water and hydroxyl groups on nitrogen doped TiO(2) have little correlations with their crystallite phases (anatase or rutile) and photocatalytic activity. The more abundant surface states characterized by photoluminescence spectroscopy together with the lowered valence band maximum of rutile TiO(2) by nitrogen doping are considered as the key factors for the higher activity of nitrogen doped TiO(2) with higher content of rutile phase.