Development and Application of Instrumental Methods for Strain Analysisof Semiconductor Layers and Devices

 Strain effects on semiconductor layers were studied by means of optical spectroscopic techniques with a device developed especially for the study of layered structures and microstructures. Raman, modulated photoreflectance and reflectance anisotropy spectroscopy (RAS) were applied. Measurements were performed on elemental semiconductors (Si), semiconductor alloys (Si–Ge) and III–V semiconductor compounds (GaAs). By application of RAS, strains lower than 10⁻⁴ could be resolved, which is at least one order of magnitude lower than those observable with Raman and modulated reflectance techniques. The RAS spectra of layers strained along either the [010] or [011] direction showed a derivative-like structure at E₁-gap energies, which increased linearly and very quickly with increasing strain. The dependence of this spectral feature on applied strain was used to evaluate strain-dependent effects. This behaviour strongly suggests that RAS can be applied for the optical characterisation of strain in semiconductor microstructures and devices, with a higher efficiency and accuracy than that achieved by previously established optical methods such as Raman and modulation spectroscopy. In addition, the compactness and ease of operation of the instrumentation of RAS provides considerable potential for in situ monitoring/control of semiconductor fabrication conditions.     

螯合树脂研究——Ⅺ.一类新的氨基二硫代甲酸型螯合树脂的合成及吸附性能

本文报道了以多乙烯多胺为主链的巯基胺树脂与二硫化碳反应,合成了四种新型的氨基二硫代甲酸型螯合树脂,这类树脂对贵金属具有高的吸附容量和优良的吸附选择性。并通过红外光谱和X光电子能谱研究树脂及其金属螫合物。     

Determination of cobalt in water samples by photoacoustic spectroscopy with a solid-phase spectrophotometry approach using 3-(2-pyridyl)-5,6-bis(4-sulfophenyl)-1,2,4-triazine

This work forms part of an investigation which seeks to determine metal complexes in a solid phase by photoacoustic spectrometry (PAS). Results of spectral determination of Co(II) complexes are introduced. The method is based on Co(II) colorimetric reaction with 3-(2-pyridyl)-5,6-bis(4-sulfophenyl)-1,2,4-triazine (FST, ferrozine) retained on an anion-exchange resin, DEAE Sephadex A-25. The immobilization of Co(II) on the solid phase is combined with PAS measurement. A numerical approach is applied to reduce noise in the spectral data. At λ = 477 nm, the calibration for Co(II) is linear over the range 14–300 μgL^{− 1}. The Co(II) concentration in water samples was determined by conventional photoacoustic measurement. The relative standard deviation (R.S.D.) of the method for the calibration is < 5%. Under optimized conditions, the obtained analytical features were LOD 14 μgL^{− 1} and LOQ 45 μgL^{− 1}.     

Characterization of multilayer nanofiltration membranes using positron annihilation spectroscopy

Positron annihilation spectroscopy (PAS) coupled with a slow positron beam was used to characterize in situ the layer structure and depth profile of the cavity size in thin film composite (TFC) polyamide nanofiltration (NF) membranes prepared by the interfacial polymerization method. Two techniques, using PAS coupled with a slow positron beam of Doppler broadening energy spectra (DBES) and positron annihilation lifetime spectroscopy (PALS) designed to reveal the layer structure and the cavity sizes contained in a multilayer thin film composite NF membrane, were assessed. To the best knowledge of the authors, a characterization of the depth profile of cavities in NF membranes using PAS coupled with a slow positron beam has never been reported. The membranes selected have a composite structure containing three layers: a selective polyamide layer, a transition layer, and a porous support prepared by the phase inversion technique. Furthermore, the cavity size distribution in the selective top layer plays an important role in determining the performance of the NF membranes.     

快扫描傅立叶变换红外光声光谱对SBS/PET双层复合材料的研究

采用快扫描傅立叶变换红外光声光谱研究了苯乙烯-丁二烯-苯乙烯嵌段共聚物/聚对苯二甲酸乙二醇酯 (SBS/PET)双层复合材料.以碳黑膜作参比,氦气作吹扫气体,分辨率设定为8 cm-1,通过调节干涉仪动镜速率,获得了不同实验条件下的红外光声光谱图.比较了相同和不同速率时单一样品以及样品间的光谱变化.对3种不同表层厚度的样品,在同一动镜速率下,表层SBS越薄,其光谱信息越小,通过对特征吸收峰强度的对比,有效比较了其样品表层的厚度.随着动镜速率的逐渐增大,表层光谱特征被相对加强,同时底层光谱特征相对减弱.研究表明,采用快扫描红外光声光谱,在不破坏、不接触双层样品的情况下,通过改变动镜速率即可对表层和底层材料进行分析,并对表层SBS膜厚度进行区分.     

Thermal Treatments of Fe—Mn Alkoxide of Glycerol: Infrared absorption and emission spectroscopy

Synthetic Fe—Mn alkoxide of glycerol samples are submitted to controlled heating conditions and examined by IR absorption spectroscopy. On the other hand, the same sample is studied by infrared emission spectroscopy (IRES), upon heating in situ from 100 to 600°C. The spectral techniques employed in this contribution, especially IRES, show that as a result of the thermal treatments ferromagnetic oxides (manganese ferrite) are formed between 350 and 400°C. Some further spectral changes are seen at higher temperatures.This revised version was published online in November 2005 with corrections to the Cover Date.     

Spectroscopic,Magnetic and Thermal Investigations on Cu(II), Mn(II), Co(II) and Fe(III) Complexes with Glutamyl Nitroanilide

New complexes CuL₂×2H₂O, CoL₂×3H₂O, MnL₂×2H₂O and FeL₃×2H₂O, L=γ-L -glutamyl-5-(p-nitroanilide), were synthesized and characterized by their spectral, magnetic and thermal properties. The thermal stabilities of the synthesized complexes were examined in the temperature range 20–500°C. In all these complexes γ-L -glutamyl-5-(p -nitroanilide) acts as a bidentate ligand, its coordination involving the carbonyl oxygen and the nitrogen atom of the second amino group. The local structure around the Cu(II) ion is pseudotetrahedral. In the Co(II), Mn(II) and Fe(III) complexes, the metal ions are in the high-spin form, with octahedral stereochemistry. This revised version was published online in August 2006 with corrections to the Cover Date.     

Surfactin-like structures of five cyclic depsipeptides from the marine isolate ofBacillus pumilus

Five cyclic depsipeptides with molecular masses of 1007, 1021, 1021, 1035, and 1035 were obtained fromBacillus pumilus KMM 150 associated with Australian marine spongeIrcinia sp. Their structures were assigned by mass spectrometric techniques (high-resolution fast atom bombardment and electron impact mass spectrometry), chemical modification, and extensive spectroscopic analysis, including several types of two-dimensional NMR.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 979–983, May, 1995.The authors are grateful to Dr. V. V. Mikhailov, the Head of the Laboratory of marine microbiology of PIBC of the Far-Eastern Branch of the RAS, and to Dr. E. P. Ivanova for isolation, systematic determination, and cultivation of the strain KMM 150. The authors are also thankful to T. I. Zykova for carrying out the fermentative hydrolysis of peptide4c.     

Application of two‐dimensional near‐infrared (2D‐NIR) correlation spectroscopy to the discrimination of three species of Dendrobium

The objective of this paper was to apply two‐dimensional (2D) near‐infrared (NIR) correlation spectroscopy to the discrimination of three species of Dendrobium. Generalized 2D‐NIR correlation spectroscopy was able to enhance spectral resolution, simplify the spectrum with overlapped bands and provide information about temperature‐induced spectral intensity variations that was hard to obtain from one‐dimensional NIR spectroscopy. The FT‐NIR spectra were measured over a temperature range of 30–140°C. The 2D synchronous and asynchronous spectra showed remarkable differences within the range of 5600–4750 cm⁻¹ between different species of Dendrobium. Copyright © 2009 John Wiley & Sons, Ltd.     

Plant Coumarins. 3. (+)-PTeryxin from <Emphasis Type="Italic">Peucedanum terebinthaceum</Emphasis>

The potentially medically valuable pyranocoumarin (+)-pteryxin was isolated for the first time from Peucedanum terebinthaceum Fischer et Turcz. The structure of (+)-pteryxin was rigorously proved using mass spectrometry, NMR, IR, and UV spectroscopy and comparison of the spectral characteristics of this compound and its basic hydrolysis products (+)-cis- and (−)-trans-khellactone and angelic and acetic acids. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 468–470, September-October, 2008.     

Effect of inert diluent segment on the miscibility behavior of poly(vinylphenol) with poly(acetoxystyrene) blends

Polymer blends of poly(vinylphenol) (PVPh) and poly(styrene‐co‐vinylphenol) with poly(p‐acetoxystyrene) (PAS) were prepared by solution casting from tetrahydrofuran solution. The thermal properties and hydrogen bonding of the blends were investigated by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy. Although hydrogen bonding existed between the PVPh and PAS segments, the experimental results indicated that PVPh is immiscible with PAS as shown by the existence of two glass‐transition temperatures over the entire composition range by DSC. This phenomenon is attributed to the strong self‐association of PVPh, intramolecular screening, and functional group accessibility effects of the PVPh/PAS blend system. However, the incorporation of an inert diluent moiety such as styrene into the PVPh chain renders the modified polymer to be miscible with PAS. Copolymers containing between 16 and 51 mol % vinylphenol were fully miscible with PAS according to DSC studies. These observed results were caused by the reduction of the strong self‐association of PVPh and the increase of the interassociation between PVPh and PAS segments with the incorporation of styrene on the PVPh chain. According to the Painter‐Coleman association model, the interassociation equilibrium constant of PVPh/PAS blends was determined by a model compound and polymer blend. Good correlation between these two methods was obtained after considering the intramolecular screening and functional group accessibility effect in the polymer blend. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1661–1672, 2002     

Photo-induced interfacial electron transfer from CdSe quantum dots to surface-bound <Emphasis Type="Italic">p</Emphasis>-benzoquinone and anthraquinone

Here we report transient spectral red-shift and transient absorption enhancement of p-benzoquinone radical in the presence of CdSe quantum dots after 355 nm pulse laser excitation. The spectral shift was caused by surface-bound p-benzoquinone molecules while the transient absorption increase was due to interfacial electron transfer from CdSe quantum dots to p-benzoquinone molecules. In contrast, spectral shift and absorption increase were much less significant for anthraquinone in the presence of CdSe quantum dots due to their weak adsorption abilities.     

Interactions of Safranin T with Nucleic Acids

The interactions of Safranin T (ST) with several nucleic acids have been investigated by electrochemical, UV‐visible and CD spectroscopic techniques. The form of the nucleic acid‐ST complexes is sensitive to the ratio of the two species. Two electrochemically inactive complexes such as, nucleic acid‐ST and nucleic acid‐2ST, were formed while ST interacts with nucleic acids. Two processes were obtained from spectral experiments: (1) at the high value of R (R is defined as the ratio of the total concentration of ST to that of nucleic acid), ST is groove‐binding with stacking, (2) at the low value of R, ST is groove‐binding without stacking. Intrinsic binding constants were obtained by spectral methods. The experiments also show that electrostatic binding plays an important role in the interaction of ST with nucleic acids.     

Synthesis of cyasteronylthiocarbamate derivatives

Ecdysterone, cyasterone, ajugalactone, ajugasterone B, 22-acetylcyasterone, and turkesterone were isolated from leaves of Ajuga turkestanica (Labiatae). Their structures were established using spectral and chemical data. The 2,3,22-triacetate, 2,3,22-tri-O-p-iodobenzoylthiocarbamate, and 2-O-p-iodobenzoylthiocarbamate derivatives of cyasterone were synthesized. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 449–451, September–October, 2006.     

PAS-Formaldehyde Polymer as a Polymeric Ligand

p-Aminosalicylic acid (PAS) was condensed with formaldehyde in the presence of aqueous oxalic acid and aqueous sodium hydroxide. The polymer sample (PAS-F,1) obtained withacid catalyst was characterized by IR spectral study, by its M_n determined by nonaqueous conductometric titration both against standard acid and alkali, by viscometric study in formic acid, and by DTA. The IR spectral and general characteristics of a polymer sample (PAS-F,2) prepared in the presence of aqueous alkali resemble those of a polymer sample (AP-F) prepared similarly from m-aminophenol and formaldehyde, indicating decarboxylation of PAS during the base-catalyzed polymerization of PAS with formaldehyde. Polymeric metal chelates of Fe(III), Cu(II), Zn(II), and Mn(II) ions with the PAS-F,1 polymer sample have been prepared and characterized by elemental analyses, IR spectral study, measurements of magnetic moments, and thermal analyses. Chelation ion-exchanging properties of the PAS-F,1 polymer sample have also been studied employing the batch equilibration method.     

Two new diterpene and sesquiterpene from Pteris dispar

A new diterpene and a new sesquiterpene were isolated from Pteris dispar and identified on the basis of spectral data including 2D NMR.Compounds 1 and 2 showed potent cytotoxic activity against KB cell.     

Alkaloids from Plants of the Nitraria Genus. Structure of Sibiridine

The new alkaloid sibiridine was isolated from the aerial parts of Nitraria sibirica and N. schoberi. Its structure was established using spectral data and chemical transformations. Its synthesis was carried out.     

X-ray diffraction analysis and spectral studies of new derivatives of pyrazol-5-one

The molecular and crystal structures of 4-acetamido-2,3-dimethyl-1-phenylpyrazol-5-one (1) and 4-maleylamido-2,3-dimethyl-l-phenylpyrazol-5-one (2) were studied. The molecular conformations are stabilizedvia systems of intermolecular hydrogen bonds between the amide groups and the carbonyl oxygen atoms of the pyrazolone rings. The conformation of compound 2 is additionally stabilizediva an intramolecular interaction between the carboxyl group and the amide oxygen atom. According to the IR spectral data, protonation of the compounds under study in an acetonitrile solution occurs at the carbonyl oxygen atom of the pyrazolone ring, which is also confirmed by the UV spectral data. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1286–1292, July, 1999.     

A Simple Indirect Route for the Synthesis of N-Alkyl-4-imino-1,4-dihydro-2H-3,1-benzoxazin-2-ones

Summary. Novel N-alkyl-4-imino-1,4-dihydro-2H-3,1-benzoxazin-2-ones were synthesized in a single step by Baeyer–Villiger oxidation of N-alkyl-3-imino-2-indolinone derivatives in high yields. The structures of the products were determined by spectral data and by X-ray diffraction. Besides their novel structures, these compounds may have important biological activities and industrial applications.