Comparative analysis of photoluminescence and Raman enhancement by metal nanoparticles

We present a comparative study on the enhancement of photoluminescence and Raman processes by a single metal nanoparticle. Taking an analytical approach, we show the physics behind strikingly different orders of magnitude in enhancement that have been observed, provide fundamental explanation for not observing quenching of Raman processes, and outline the path to optimization of both photoluminescence and Raman enhancement.     

Comparative estimate of the efficiency of the sorption extraction of iodine from chloride solutions

The possibility of applying activated carbon and polymeric sorbents poly(4-vinylpyridine), polytrimethylsilylpropyne (PTMSP), bromo-substituted PNMSP (Br-PNMSP), poly(N-methyl-4-vinylpyridinium iodide) for the sorption recovery of iodine from a 0.5 M solution of sodium chloride is studied. The dependence of iodine sorption on the pH of solution, the amount of adsorbent, and the duration of contact between the solution and adsorbent is studied. The highest sorption capacity (G = 616.78 mg/g) is attained by using poly(N-methyl-4-vinylpyridinium iodide) anionite with the addition of iodine to form complex triiodide ions. The dynamics of iodine adsorption on poly(4-vinylpyridine) is described by a kinetic model of pseudosecond order. The composition and structure of the iodine compounds sorbed by polymers and activated carbon are studied by Raman spectroscopy (RS).     

Bis{(μ-acetato)[μ-bis(salicylidene)-1,3-propanediaminato]zinc(II)}zinc(II)

In the title linear trinuclear compound, [Zn{Zn(CH₃COO)(C₁₇H₁₆N₂O₂)}₂], the central Zn²⁺ ion, which is located on an inversion centre, has a distorted octahedral coordination involving four bridging O atoms from two N,N′-bis­(salicyl­idene)-1,3-propane­diaminate ligands in the equatorial plane and one O atom from each bridging acetate group in the axial positions. The coordination around the terminal Zn²⁺ ion is irregular square pyramidal, with two O and two N atoms of the ligand in the basal plane and one O atom from an acetate group in the apical position. The acetate bridges linking the central and terminal Zn²⁺ ions are mutually trans. The Zn⃛Zn distance is 3.0520 (8) Å. The relationship of this structure to that of [Zn{Cu(CH₃COO)(C₁₇H₁₆N₂O₂)}₂] is discussed.     

铟封稳频He－Ne激光器

稳频Ｈｅ－Ｎｅ激光器中布氏窗片的封接引起的各向异性损耗，是影响激光输出功率的主要因素。采用先进的铟封接技术，可以大大改善稳频管的窗口封接质量，从而减小了腔的损耗，明显地提高了稳频Ｈｅ－Ｎｅ激光器的输出功率。     

半导体长波长异质结构材料光压谱测试探讨

本文介绍了ＩｎＰ、ＩｎＧａＡｓ、ＩｎＧａＰ、ＩｎＧａＡｓＰ等的光压港（ＰＶＳ）。并把ＩｎＧａＡｓＰ（在特定组份下）的ＰＶＳ与ＦＦＴ—ＰＬ谱进行了比较；分析和讨论了ＰＶＳ测试的局限性和复杂性；指出了对多层异质结构材料，只有把器件结构、外延工艺、ＥＣＶ测试等结合起来，才可能正确地理解ＰＶＳ给出的测试结果。     

Device Performance Optimization of Organic Thin-Film Transistors at Short-Channel Lengths Using Vertical Channel Engineering Techniques

Semiconductors - This paper presents a finite-element-based two-dimensional numerical simulation study of the vertical channel engineering approaches for controlling the short-channel effects...     

A study of dendrites in quenched mercury-cadmium telluride

Dendritic structures in quenched ingots of mercury-cadmium telluride have been investigated by electron microprobe analysis and metallographic method. It is possible to deduce the movement of the solidification interfaces during the quenching period from the configuration and distribution of dendritic patterns on crystal slices, and to qualitatively predict the lateral composition uniformity of the crystal after recrystallization as well. Based on this assessment, a simple criterion for evaluating the quality of quenched mercury-cadmium telluride ingot is proposed.     

HBF4·DEE-catalyzed formation of sulfinyl imines: Synthesis and mechanistic studies

A mild acid-catalysed method is reported for the formation of sulfinyl imines from tert-butanesulfinamide and aromatic or aliphatic aldehydes using tetrafluoroboric acid diethyletherate (10?mol%) in dichloromethane. Reactions were performed at room temperature and gave the corresponding sulfinyl imines in excellent yield after 2?h. A DFT study was performed and a mechanism for the reaction is postulated.