X射线光电子能谱仪的开放使用与管理

X射线光电子能谱仪(XPS)是材料表面元素定性和半定量分析的重要手段之一,是表面分析科研工作的必备仪器.为提高测试效率,实施了大型仪器设备开放共享优化,总结了在推动XPS开放过程中管理的经验和体会.     

An Open‐Circuit Voltage and Power Conversion Efficiency Study of Fullerene Ternary Organic Solar Cells Based on Oligomer/Oligomer and Oligomer/Polymer

Variations in the open‐circuit voltage (V _oc) of ternary organic solar cells are systematically investigated. The initial study of these devices consists of two electron‐donating oligomers, S2 (two units) and S7 (seven units), and the electron‐accepting [6,6]‐phenyl C71 butyric acid methyl ester (PC₇₁BM) and reveals that the V _oc is continuously tunable due to the changing energy of the charge transfer state (E _ct) of the active layers. Further investigation suggests that V _oc is also continuously tunable upon change in E _ct in a ternary blend system that consists of S2 and its corresponding polymer (P11):PC₇₁BM. It is interesting to note that higher power conversion efficiencies can be obtained for both S2:S7:PC₇₁BM and S2:P11:PC₇₁BM ternary systems compared with their binary systems, which can be ascribed to an improved V _oc due to the higher E _ct and an improved fill factor due to the improved film morphology upon the incorporation of S2. These findings provide a new guideline for the future design of conjugated polymers for achieving higher performance of ternary organic solar cells.

     

窄内径多孔层开管柱的制备及在液相色谱中的应用

近年来,微纳分离技术由于其内在的优势而受到越来越多的关注.多孔层开管柱是一种重要的微分离柱形式,与粗内径的多孔层开管柱(>25μm)相比,窄内径的多孔层开管柱具有更高的分离效率和更低的试剂消耗量.本文综述了内径≤25μm的窄内径多孔层开管毛细管柱的制备方法、与质谱检测联用技术以及在液相色谱中的应用研究进展,对其发展前景进行了展望.     

Polydopamine‐assisted immobilization of zeolitic imidazolate framework‐8 for open‐tubular capillary electrochromatography

In this work, we developed a capillary column modified with zeolitic imidazolate framework‐8 as a novel stationary phase for open‐tubular capillary electrochromatography. To immobilize zeolitic imidazolate framework‐8 onto the inner surface of silica capillary, a bio‐inspired polydopamine functionalization was used to functionalize the capillary surface with polydopamine. First, a polydopamine layer was assembled inside the capillary. Second, due to noncovalent adsorption and covalent reaction ability, polydopamine could attract and anchor zeolitic imidazolate framework‐8 onto the inner surface of capillary. It has been demonstrated that zeolitic imidazolate framework‐8 was successfully grafted on the inner wall of the capillary by scanning electron microscopy, and Fourier transform infrared spectroscopy. The electro‐osmotic flow characteristics of capillaries were also investigated by varying the pH value and acetonitrile content of mobile phase. The zeolitic imidazolate framework‐8 coating not only increased the phase ratio of open‐tubular column, but also improved the interactions between tested analytes and the stationary phase. Three groups of isomers including acidic, basic, and neutral compounds were well separated on the zeolitic imidazolate framework‐8 bonded column, with theoretic plate numbers up to 1.9 × 10⁵ N for catechol. The repeatability of the prepared columns was also studied, and the relative standard deviations for intra‐ and interday runs were less than 5%.     

Open tubular capillary column of 50 μm internal diameter with a very high separation efficiency for the separation of peptides in CEC and LC

A specially designed long open tubular capillary column (50 μm internal diameter and 112 cm effective length) was prepared by fabrication of a thin three‐component co‐polymer layer on the inner surface of silica capillary. A pretreated silica capillary was reacted with 4‐(chloromethyl)phenyl isocyanate in the presence of dibutyltin dichloride as catalyst followed by sodium diethyl dithiocarbamate. Then a thin polymer layer was made on the inner surface of capillary by reversible addition‐fragmentation transfer polymerization of styrene, N‐phenylacrylamide, and methacrylic acid. A carefully adjusted formulation of reaction mixture and elaborated procedures were adopted to secure formation of the co‐polymer layer of enhanced separation performance. The co‐polymer immobilized open tubular capillary column was used for the separation of a synthetic mixture of five peptides and excellent separation efficiency (over 1.7 million per column) was obtained in the capillary electrochromatography mode. Such excellent separation efficiencies of ca. 1 m column have not been obtained in the isocratic elution mode so far. The column was also used for separation of the peptides in the liquid chromatography mode to show very good separation efficiency (average 286 700 per column).     

Lot‐sizing policies for deterioration items under two‐level trade credit with partial trade credit to credit‐risk retailer and limited storage capacity

The main purpose of this article is to investigate the optimal wholesaler's replenishment decisions for deterioration items under two levels of the trade credit policy and two storage facilities in order to reflect the supply chain management situation within the economic order quantity framework. In this study, each of the following assumptions have been made: (1) The own warehouse with limited capacity always is not sufficient to store the order quantity, so that a rented warehouse is needed to store the excess units over the capacity of the own warehouse; (2) The wholesaler always obtains the partial trade credit, which is independent of the order quantity offered by the supplier, but the wholesaler offers the full trade credit to the retailer; (3) The wholesaler must take a loan to pay his or her supplier the partial payment immediately when the order is received and then pay off the loan with the entire revenue. Under these three conditions, the wholesaler can obtain the least costs. Furthermore, this study models the wholesaler's optimal replenishment decisions under the aforementioned conditions in the supply chain management. Two theorems are developed to efficiently determine the optimal replenishment decisions for the wholesaler. Finally, numerical examples are given to illustrate the theorems that are proven in this study, and the sensitivity analysis with respect to the major parameters in this study is performed. Copyright © 2016 John Wiley & Sons, Ltd.     

绿色氧化法制备联苯类化合物的研究性实验设计与实践*

以苯甲醛和丙酮为原料,利用Robinson增环反应先制备3-甲基-5-苯基环己-2-烯-1-酮,再引导学生设计并研究了水相绿色氧化3-甲基-5-苯基环己-2-烯-1-酮合成联苯类化合物3-乙氧基-5-甲基-1,1′-联苯的影响因素,利用核磁共振确定了产物结构。该研究性实验教学以绿色化学为中心,结合了2步连续反应,产物易提纯且产率高,并开展了开放式大型分析仪器教学和测试,对学生有机合成实验能力和科学研究能力的培养具有很好的教学效果。     

FEEDBACK CONTROL OPTIMIZATION FOR SEISMICALLY EXCITED BUILDINGS

A feedback control optimization method of partially observable linear structures via stationary response is proposed and analyzed with linear building structures equipped with control devices and sensors. First, the partially observable control problem of the structure under horizontal ground acceleration excitation is converted into a completely observable control problem. Then the It6 stochastic differential equations of the system are derived based on the stochastic averaging method for quasi-integrable Hamiltonian systems and the stationary solution to the Fokker-Plank-Kolmogorov （FPK） equation associated with the It6 equations is obtained. The performance index in terms of the mean system energy and mean square control force is established and the optimal control force is obtained by minimizing the performance index. Finally, the numerical results for a three-story building structure model under E1 Centro, Hachinohe, Northridge and Kobe earthquake excitations are given to illustrate the application and the effectiveness of the proposed method.     

An experimental study of the effect of wall temperature nonuniformity on natural convection in an enclosure heated from the side

An experimental study of natural convection in a parallelepipedal enclosure induced by a single vertical wall is described. The upper half of this wall was warm and the lower half cold. The other enclosure walls were insulated. The temperature and flow measurements were performed in the high Rayleigh number regime (10¹⁰<Ra<5×10¹⁰) by using water as the working fluid. The Rayleigh number was based on the enclosure height and the temperature difference between the warm and the cold part of the driving wall. The flow field featured two flat cells, one filled with warm fluid along the top horizontal wall, and the other filled with cold fluid along the bottom horizontal wall. Each of these cells was surrounded by an additional cell as tall as half the enclosure height. The above flow structure prohibited extensive thermal contact between warm and cold fluid, thus limiting the role of convection on the heat transfer process in the cavity. The findings of this study differ significantly from the findings of previous studies based on the ‘classical’ enclosure model possessing two isothermal vertical walls, the one warm and the other cold, and support the view that the use of ‘more realistic‘ temperature boundary conditions in enclosure natural convection needs careful examination.