Improvement of the electrical properties of Se3Te1 thin films by In additions

The electronic and photoconductivity properties of semiconducting chalcogenide glasses have been largely stimulated by attractive micro-electronic device applications. The present paper aims to study the effect of In additions on the steady state and transient photoconductivity of amorphous In_x(Se₃Te₁)_100 ? x (0 ≤ x ≤ 10 at.%) chalcogenide films. It was found that, the Indium additions lead to the decrease of both the activation energies (ΔE_dc in the dark and ΔE_ph for the photoelectrical conduction) and the optical band gap E_g that improved the electrical properties of these films. The photoconductivity increases while photosensitivity changes from 8.73 to 7.18 with the increase of In content. The exponential dependence of photocurrent on the light intensity suggests that, the recombination mechanism in these films is due to bimolecular recombination. The transient photoconductivity measurements stated that, the carrier lifetime decreased by the increase of the light intensity and In content. The obtained results were discussed in terms of the width of localized states (Mott and Davis model) and the chemical-bond approach.     

Synthesis, reactions and antimicrobial activities of 8-ethoxycoumarin derivatives

Condensation of 3-acetyl-8-ethoxycoumarin (3) with thiosemicarbazide gave ethylidenehydrazinecarbothioamide 5, which was transformed into the thiazolidin-4-one derivatives 6,7. Interaction of 3 with DMF/POCl(3) gave b-chloroacroline derivative 8. Treatment of 3 with malononitrile gave benzo[c]chromone and 2-aminobenzonitrile derivatives 9 and 10, respectively with respect to the reaction conditions. Condensation of 3-(2-bromoacetyl)-8-ethoxycoumarin (4) with o-phenylenediamine gave 3-(quioxaline-2-yl)-8-ethoxycoumarin hydrobromide (11), while 4 reacted with 2-aminopyridine to give chromenopyridopyrimidine derivative 12. Condensation of 4 with potassium thio-cyanate/methanol gave an unexpected derivative, 2H-chromeno-3-carboxy(methyl-carbonimidic)thioanhydride 16, which upon treatment with (NH(2))(2)·H(2)O gave 3-ethoxy-2-hydroxybenzaldehyde azine 19. Interaction of 4 with thiourea derivatives gave thiazole derivatives 20a-c. The structures of the newly synthesized compounds were confirmed by their spectra data. The newly synthesized compounds were also screened for their antimicrobial activity.     

Thioimidazolate versus pyrazolate-zinc(II)-bound hydroxo complex as structural model for the active site of hydrolytic enzyme: the crystal structure of the inclusion complex TtZn–O–C6H4–p-NO2, Tt?=?hydrotris(N-xylyl-2-thioimidazolyl)borate

The reaction of the tripod ligand hydrotris(N-(2-methylphenyl)-2-thioimidazol-1-yl)borate, Tt with zinc(II) chloride yielded the chloro complex [TtZn–Cl] 1. The hydrolytic reactivity of its hydroxo complex [TtZn–(μ-OH)ZnTt]Cl 2 towards p-nitrophenyl acetate was hampered due to the formation of the stable phenolate complex [TtZn–O–Ar–p-NO₂] 3 as a product inhibition. The X-ray structure analysis of complex 3 was determined and showed that its Zn[S₃O] coordination sphere includes three thione donors from the ligand Tt and one oxygen donor from the hydrolysed product p-nitrophenolate in an ideally tetrahedral arrangement around the zinc(II) centre.     

Study of precipitates formation in Al‐4.5Wt%Cu and Al‐4.5Wt%Cu‐0.1Wt%In alloys using creep measurements and positron annihilation technique

The transient and steady state creep deformation of Al‐4.5 wt%Cu and Al‐4.5 wt%Cu‐0.1 wt%In alloys were studied using a constant stress in the aging temperatures range 403 to 703 K for various aging times under different working temperatures. Positron annihilation studies using Doppler–broadening measurements were carried out on the specimens used in creep measurements. The subsequent decrease and increase in the creep parameters n, β and ε_st as well as in Doppler lineshape parameter with increasing aging temperatures and aging times were explained on the basis of structure transformations occuring in Al‐Cu alloys. The mechanical creep measurements are very well correlated with positron annihilation characteristics. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Investigation of the effect of drying and refining on the fiber–fiber shear bond strength measured using tensile fracture line analysis of sheets weakened by acid gas exposure

No reliable method exists for measuring the cellulose fiber–fiber shear bond strength in paper. This paper reports a simple method for measuring the fiber–fiber shear bond strength by weakening the fibers independently of the bonds in a sheet of paper, using acid vapor, until all the fibers break across the fracture line. The bond strength is then calculated from the fiber strength, as measured by the zero span test, at the point where the fibers first are weakened such that they all break. The method was used to calculate the average bond strength of handsheets made out of two different pulps. The first pulp was a never dried, 60% yield, unbleached radiata pine. The bond strength was 25.0 ± 3.3 MPa. Drying the fibers before reslushing and making sheets reduced the bond strength by up to 33%, with the reduction depending on the severity of the drying treatment. The second pulp was a bleached dried softwood kraft and was used to investigate the effect of low consistency refining on bond strength. The bond strength increased from 13.7 ± 1.0 MPa for the sheets made from the unrefined pulp to 37.0 ± 1.0 MPa, for the sheets made from the most heavily refined pulp. The bond strength measurements are considerably higher than previous literature estimates for the shear bond strength. The causes for the discrepancy include stress concentrations in tests of single fiber–fiber bonds.     

Studies on arylhydrazonoisoxazolinethiones. Behaviour of 4-arylhydrazono-3-phenyl-2-isoxazoline-5-thiones toward hydrazines,grignard reagents and alkylating agents

The 4-arylhydrazono-3-phenyl-2-isoxazoline-5-thiones 2 react with hydrazines to yield the 5-hydrazones 3 and 5 . The reaction of 2 with Grignard reagent resulted in addition of the reagent to the thiocarbonyl group to yield 7 . Treatment of 2 with diazomethane effected S - and N -methylation beside 1,2,3-triazole derivative 11 obtained through isomerisation. The potassium salt of 2 react with alkyl halides to yield the S-alkyl derivatives 12 .     

Pre—Separation Axioms in Fuzzifying Topology

1　 IntroductionYing[5,6 ] introduced and elementally developed so called fuzzifying topology with the semanticmethod of continuous valued L ogic.Shen[7] introduced and studied T0 -,T1-,T2 (Hausdorff) -,T3(regularity) -,T4 (normality) -separation axioms in fuzzifying topology.In [3 ]the concepts of thefamily of fuzzifying pre-open sets,fuzzifying pre-neighbourhood structure of a point and fuzzifyingpre-closure are introduced and studied.It is worth to mention that pre-separation axioms are …     

名义组份Bi6Se9Ge4CuOx块材和粉末压实样品的热电势和电导率

采用熔化淬火工艺制备Bi6Se9Ge4CuOx。块材和粉末压实样品均在300℃进行了热处理,该温度远低于玻璃转变温度419℃（由DTA热重分析得知）。无论是末经处理还是热处理后的样品,都具有多相结构。热电势测量结果表明,可能有电子和空穴的导电。载流子的导电类型主要取决于热处理条件。热电势以扩散分量为主,声子曳引可以忽略。跳跃导电是常见的,而半金属行为只在特殊的热处理条件下出现。     

LINEAR SEARCH FOR A BROWNIAN TARGET MOTION

A target is assumed to move according to a Brownian motion on the real line. The searcher starts from the origin and moves in the two directions from the starting point.The object is to detect the target. The purpose of this paper is to find the conditions under which the expected value of the first meeting time of the searcher and the target is finite,and to show the existence of a search plan which made this expected value minimum.