FTC网在双加压硝酸装置上的应用

介绍了FTC网在双加压硝酸装置上的应用情况,分析了其在使用过程中出现的问题,并提出了解决的办法.     

In situ characterization of localized corrosion of stainless steel by scanning electrochemical microscope

Scanning electrochemical microscopy (SECM) area scan measurements have been performed to investigate the localized corrosion of type 304 stainless steel in neutral chloride solution. Variations in the Faradaic current measured at selected tip potential values can be related to changes in the local concentration and electrochemical activities of electroactive species involved in corrosion reactions occurring at the substrate as a function of immersion times of the substrate and polarized currents or potentials applied on the substrate. To further verify the results acquired from cyclic voltammetric experiments, SECM measurements were employed to in situ study the compositions and electrochemical activity distribution profile of the pitting corrosion products of stainless steel. It has been demonstrated that the combination of feedback current mode with generation-collection (G-C) mode of SECM is suitable to elucidate the possible reaction mechanisms and paths involved in the localize corrosion of stainless steel in neutral chloride solution.     

From salmon pink to blue natural sensitizers for solar cells: Canna indica L., Salvia splendens, cowberry and Solanum nigrum L.

Study on dye-sensitized solar cells (DSSCs) with extracts of Canna indica L., Salvia splendens, Solanum nigrum L. as sensitizers is firstly reported in this paper. DSSCs were assembled by using natural dyes extracted from C. indica L., S. splendens, cowberry and S. nigrum L. as sensitizers. The energy conversion efficiency of the cells sensitized with dyes of C. indica L., S. splendens, cowberry and S. nigrum L. was 0.29%, 0.26%, 0.13% and 0.31%, respectively. A novel technique was taken to fabricate TiO₂ electrode films by electrophoresis. We present FTIR and UV–vis spectroscopy studies of structures and light absorption of these four kinds of natural dyes. The electrochemical impedance spectroscopy (EIS) was used to analyze the interface resistance of cells. The result indicated that high resistance existed in the interfaces of cell with cowberry extract as sensitizer.     

p型氮化镓的低温生长及发光二极管器件的研究

采用金属有机物化学气相淀积技术(MOCVD)在蓝宝石衬底上低温(870—980℃)生长p型氮化镓 (p-GaN).用Hall测试仪测量材料的电学性能，发现当温度低于900℃时，材料的电阻率较高 ；在900—980℃均可获得导电性能良好的p-GaN.另外，电导性能除与掺杂浓度有关，还与p- GaN生长条件有关，氮镓摩尔比过低导电性能就较差，过高则会引起表面粗糙.采用优化后的 p-GaN制作了绿光发光二极管器件，发现生长温度越低器件发光强度越高，反向电压也越高 ，但正向电压只是略有升高. 关键词： Ⅲ-Ⅴ族半导体 氮化镓 发光二极管 金属有机物化学气相淀积     

Characterization of Ti-Zr-N films deposited by cathodic vacuum arc with different substrate bias

Ti-Zr-N (multi-phase) films were prepared by cathodic vacuum arc technique with different substrate bias (0 to −500 V), using Ti and Zr plasma flows in residual N₂ atmosphere. It was found that the microstructure and mechanical properties of the composite films are strongly dependent on the deposition parameters. All the films studied in this paper are composed of ZrN, TiN, and TiZrN ternary phases. The grains change from equiaxial to columnar and exhibit preferred orientation as a function of substrate bias. With the increase of substrate bias the atomic ratio of Ti to Zr elements keeps almost constant, while the N to (Ti + Zr) ratio increases to about 1.1. The composite films present an enhanced nanohardness compared with the binary TiN and ZrN films deposited under the same condition. The film deposited with bias of −300 V possesses the maximum scratch critical load (L_c).     

A NOVEL BOUNDARY INTEGRAL EQUATION METHOD FOR LINEAR ELASTICITY--NATURAL BOUNDARY INTEGRAL EQUATION

The boundary integral equation (BIE) of displacement derivatives is put at a disadvantage for the difficulty involved in the evaluation of the hypersingular integrals. In this paper, the operators δij and εij are used to act on the derivative BIE. The boundary displacements, tractions and displacement derivatives are transformed into a set of new boundary tensors as boundary variables. A new BIE formulation termed natural boundary integral equation (NBIE) is obtained. The NBIE is applied to solving two-dimensional elasticity problems. In the NBIE only the strongly singular integrals are contained. The Cauchy principal value integrals occurring in the NBIE are evaluated. A combination of the NBIE and displacement BIE can be used to directly calculate the boundary stresses. The numerical results of several examples demonstrate the accuracy of the NBIE.     

诗韵钟声:时间隧道中的穿越与回归——论唐诗钟声的时间意蕴

诗与钟的结合使时间的韵律进入艺术的世界,悠悠钟声中唐代诗人丰富的内心世界展露无遗。对唐诗钟声的时间分析人们看到的不仅仅是历史长河里的时间忧患,更是一代诗人的哲学沉思。     

Luminescent Rhenium(I)–Polypyridine Complexes Appended with a Perylene Diimide or Benzoperylene Monoimide Moiety: Photophysics,Intracellular Sensing,and Photocytotoxic Activity

This communication reports novel luminescent rhenium(I)–polypyridine complexes appended with a perylene diimide (PDI) or benzoperylene monoimide (BPMI) moiety through a non-conjugated linker. The photophysical and photochemical properties originating from the interactions of the metal polypyridine and perylene units were exploited to afford new cellular reagents with thiol-sensing capability and excellent photocytotoxic activity.     

Effective removal of 2,4,6‐trinitrophenol over hexagonal metal–organic framework NH2‐MIL‐88B(Fe)

A nanostructured organic–inorganic framework, hexagonal NH₂‐MIL‐88B, has been prepared through a facile one‐pot reflux reaction and then it was characterized using various techniques. The as‐prepared sample with high specific surface area (414 m² g^?1) showed excellent adsorption for 2,4,6‐trinitrophenol (TNP) in the liquid phase. Detailed studies of the adsorption kinetics, adsorption mechanism, adsorption isotherm, activation energy and various thermodynamic parameters were conducted. The adsorption mechanism of NH₂‐MIL‐88B for TNP may be ascribed to hydrogen bond interaction, and the complexation between ─OH in TNP and unsaturated Fe(III) on the surface of NH₂‐MIL‐88B. The maximum adsorption capacity of NH₂‐MIL‐88B for TNP based on the Langmuir isotherm was 163.66 mg g^?1. The as‐prepared NH₂‐MIL‐88B adsorbent seems to be a promising material in practice for TNP removal from aqueous solution.