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排序方式: 共有399条查询结果,搜索用时 218 毫秒
71.
Rizwan Ahmed Clemens Simbrunner G. Schwabegger M. A. Baig H. Sitter 《Applied Physics A: Materials Science & Processing》2014,117(4):2235-2240
We are presenting a long-time bias stress stability of C60-based n-type organic field effect transistors (OFETs), in bottom gate, top contacts configuration, with aluminium (Al), silver (Ag) and gold (Au) source–drain contacts. The results clearly shows that the bias stress effects in C60-based n-type OFETs is similar to p-type OFETs and it can be reduced by using an appropriate metal for the source–drain contacts. During the bias stress time, the threshold voltage shift and an increase in the contacts resistance have also been measured. On the basis of the stability of the device parameters, it is proposed that the Al source–drain contact-based devices gives better stability as compared to the devices with Ag and Au source–drain contacts. Our results show that the bias stress-induced threshold voltage shift is due to the trapping of charges in the channel region and in the vicinity of the source–drain contacts. 相似文献
72.
IH Alsohaimi ZA Alothman MR Khan MA Abdalla R Busquets AK Alomary 《Journal of separation science》2012,35(19):2538-2543
Bromate is a byproduct formed as a result of disinfection of bromide-containing source water with ozone or hypochlorite. The International Agency for Research on Cancer has recognized bromate as a possible human carcinogen, thus it is essential to determine in drinking water. Present work highlights a development of sensitive and fast analytical method for bromate determination in drinking water by using ultraperformance liquid chromatography-tandem mass spectrometry. The quality parameters of the developed method were established, obtaining very low limit of detection (0.01 ng/mL), repeatability and reproducibility have been found to be less than 3% in terms of relative standard deviation when analyzing a bromate standard at 0.05 μg/mL with 0.4 min analysis time. Developed method was applied for the analysis of metropolitan and bottled water from Saudi Arabia; 22 samples have been analyzed. Bromate was detected in the metropolitan water samples (from desalinization source) at concentrations ranging between 3.43 and 75.04 ng/mL and in the bottled water samples at concentrations ranging between 2.07 and 21.90 ng/mL. Moreover, in comparison to established analytical methods such as liquid chromatography-tandem mass spectrometry, the proposed method was found to be very sensitive, selective and rapid for the routine analysis of bromate at low level in drinking water. 相似文献
73.
Natural and anthropogenic radioactivity of sand and water samples collected from the four big rivers of Punjab province, Pakistan, was measured using a high-purity germanium detector coupled with a high resolution multichannel analyser. The average concentration of the naturally occurring radionuclides (226)Ra, (232)Th and (40)K in all the sand samples from the rivers Jhelum, Chenab, Ravi and Indus was found to be 22±0.6, 36±1 and 287±10 Bq kg (-1), respectively, while the concentration of the anthropogenic radionuclide (137)Cs was found to be below the minimum detectable activity, i.e. ~1.2 Bq?kg (-1). All the sand samples have Ra(eq) concentrations lower than the limit of 370 Bq kg (-1). Indoor (H (in)) and outdoor (H (out)) radiation hazard indices were calculated for the samples to assess the radiation hazards arising due to the use of this sand in construction, and were found to be less than unity in the study area. Calculated values of the absorbed dose rate were less than the typical world average value of 59 nGy h (-1), and the annual effective dose rate was also less than the typical world value of 70 μSv, except in the Indus river, in which it is slightly higher then the world average. Results show that the measured values are comparable with other global radioactivity measurements. None of the studied riverbeds was considered a radiological hazard, and their sand can be safely used in construction. 相似文献
74.
Zhang S Zhao YG Li PS Yang JJ Rizwan S Zhang JX Seidel J Qu TL Yang YJ Luo ZL He Q Zou T Chen QP Wang JW Yang LF Sun Y Wu YZ Xiao X Jin XF Huang J Gao C Han XF Ramesh R 《Physical review letters》2012,108(13):137203
We report a large and nonvolatile bipolar-electric-field-controlled magnetization at room temperature in a Co(40)Fe(40)B(20)/Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O(3) structure, which exhibits an electric-field-controlled looplike magnetization. Investigations on the ferroelectric domains and crystal structures with in situ electric fields reveal that the effect is related to the combined action of 109° ferroelastic domain switching and the absence of magnetocrystalline anisotropy in Co(40)Fe(40)B(20). This work provides a route to realize large and nonvolatile magnetoelectric coupling at room temperature and is significant for applications. 相似文献
75.
Anyfantakis M Loppinet B Fytas G Mantzaridis C Pispas S Butt HJ 《Optics letters》2012,37(13):2487-2489
We report on the versatile effect of weak red laser light impinging on diblock copolymer [poly(isoprene-b-styrene)] dispersions in two selective solvents for each block. In the strongly scattering but transparent micellar solutions in hexane (a good solvent for polyisoprene), higher refractive index copolymer-rich fibers were formed. In the turbid dispersions of the same copolymer in ethyl acetate (a good solvent for polystyrene), the effect of self-induced transparency was observed. A two-step patterning mechanism caused the generation of a transparent microchannel, increasing light transmission. The analogy between the current effect and that observed in homopolymer polyisoprene solutions in different solvents is discussed toward an understanding of the unanticipated light-soft-matter interaction. 相似文献
76.
The present study deals with the electrochemical investigation of seven different phenols through cyclic voltammetry (CV). Phenols can be partly eliminated from aqueous solutions by electrochemically initiated polymerization. Thus, the basic CV behavior was studied under the optimized conditions such as; pH of the medium, concentration of the analyte, the supporting electrolyte, potential window, and scan rate. The CV curves of all of the phenols showed that the electro-polymerization phenomenon on the electrode surface causes surface fouling for further electrooxidation of these compounds. The influence of substituents in the ring was especially noted in terms of their tendency to foul the electrode surface. The formation of new intermediates during the electrooxidation was observed whose nature was found to be highly dependent on the type and position of the substituent. As far as the influence of pH is concerned, phenols in basic medium were electrooxidized earlier but with low current. Difference in CV response because of the substituent attached under varied pH was also noted. From the diffusion coefficient (D) and heterogeneous rate constant (k sh) mixed nature of electron transfer process was proposed. 相似文献
77.
Mikheil Doroshenko Maria Gonzales Andreas Best Hans‐Jürgen Butt Kaloian Koynov George Floudas 《Macromolecular rapid communications》2012,33(18):1568-1573
The phase separation of the polymer blend polystyrene/poly(methyl phenyl siloxane) (PS/PMPS) is studied in situ by laser scanning confocal microscopy (LSCM) and by fluorescence correlation spectroscopy (FCS) at macroscopic and microscopic length scales, respectively. It is shown for the first time that FCS when combined with LSCM can provide independent information on the local concentration within the phase‐separated domains as well as the interfacial width. 相似文献
78.
A Mukherjee M Dasgupta DJ Hinde CR Morton AC Berriman RD Butt JO Newton H Timmers 《Pramana》2001,57(1):195-198
Fusion cross-sections for the 7Li + 12C reaction have been measured at energies above the Coulomb barrier by the direct detection of evaporation residues. The heavy
evaporation residues with energies below 3 MeV could not be separated out from the α-particles in the spectrum and hence their
contribution was estimated using statistical model calculations. The present work indicates that suppression of fusion cross-sections
due to the breakup of 7Li may not be significant for 7Li + 12C reaction at energies around the barrier. 相似文献
79.
80.
Andrew J. Carrod Francesco Graglia Dr. Louise Male Dr. Cécile Le Duff Peter Simpson Dr. Mohamed Elsherif Dr. Zubair Ahmed Dr. Haider Butt Guang-Xi Xu Prof. Kenneth Kam-Wing Lo Dr. Paolo Bertoncello Prof. Zoe Pikramenou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(4):e202103541
Dual detection systems are of interest for rapid, accurate data collection in sensing systems and in vitro testing. We introduce an IrIII complex with a boronic acid receptor site attached to the 2-phenylpyridine ligand as an ideal probe with photo- and electrochemical signals that is sensitive to monosaccharide binding in aqueous solution. The complex displays orange luminescence at 618 nm, which is reduced by 70 and 40 % upon binding of fructose and glucose, respectively. The electro-chemiluminescent signal of the complex also shows a direct response to monosaccharide binding. The IrIII complex shows the same response upon incorporation into hydrogel matrices as in solution, thus demonstrating the potential of its integration into a device, as a nontoxic, simple-to-use tool to observe sugar binding over physiologically relevant pH ranges and saccharide concentrations. Moreover, the complex's luminescence is responsive to monosaccharide presence in cancer cells. 相似文献