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91.
We have developed a reliable fabrication method of forming micron scale metal patterns on poly(dimethylsiloxane) (PDMS) using a pattern transfer process. A metal stack layer consisting of Au-Ti-Au layers, providing a weak but reliable adhesion, was deposited on a silicon wafer. The metal stack layer was then transferred to a PDMS substrate using serial and selective etching. We demonstrate that features as small as 2 microm were reliably transferred on to the PDMS substrate for use as interconnects and electrodes for biosensors and flexible electronics application. 相似文献
92.
This paper describes the method of quasilinearization for first-order nonlinear impulsive functional differential equations with anti-periodic boundary conditions. A monotone iterative technique coupled with lower and upper solutions is employed to obtain sequences of approximate solutions converging monotonically and quadratically to the unique solution of the problem at hand. 相似文献
93.
94.
A novel procedure for the synthesis of β-carbolines by metal catalysed reduction of imides with sodium borohydride is described. 相似文献
95.
I. O. Abugassa Y. S. Khrbish S. O. Abugassa N. Ben Faid A. T. Bashir S. Sarmani 《Journal of Radioanalytical and Nuclear Chemistry》2007,271(1):27-30
The paper focuses on the validation of the k
0-method of instrumental neutron activation analysis (k
0-INAA) in the Tajura Nuclear Research Center (TNRC) via the analysis of several certified reference materials. The selected
reference materials were: SRM 1572 Citrus Leaves, SRM 1575 Pine Needles, IAEA-A11 Milk Powder, IAEA-V-10 Hay Powder, RM IAEA-Soil-7
and RM IAEA-SL-1 Lake Sediment. The method is based on the PC version Kayzero/Solcoi software package issued by DSM. All the
samples, reference materials and monitors were irradiated in various positions of the Tajura reactor with different f and α. The parameters f and α (f — thermal/epithermal neutron flux ratio, α — parameter accounting for the non-ideality of the 1/E epithermal neutron fluence rate distribution) were determined using the bare triple monitor method. The results obtained
for all the reference materials are in good agreement with the certified values. 相似文献
96.
Bashir S Derrick PJ Critchley P Gates PJ Staunton J 《European journal of mass spectrometry (Chichester, England)》2003,9(1):61-70
Application of matrix-assisted laser desorption/ionization (MALDI) to the analysis of dextran and dextrin derivatives, specifically glucose saccharides, by time-of-flight (TOF) mass spectrometry has been reported. MALDI-TOF analysis was carried out on alpha-, beta- and gamma-cyclodextrin, two O-methylated-beta-cyclodextrins of differing degrees of substitution (DS) and dextrans (a linear glucose saccharide), as pure and doped solutions and as mixtures of two or more of these. Doping was carried out with trace amounts of inorganic salts. The purpose of the analysis of the cyclodextrins was to determine whether they would form inclusion complexes with the various cations added, or whether less specific cation addition/exchange was occurring either prior to desorption or in the gas phase. 相似文献
97.
The effect of column temperature upon the retention of metal ions on sulfonated and mono-, di-, and amino-carboxylated cation exchange columns has been investigated. The retention of alkali, alkaline earth and transition metal ions on each of the above types of cation exchanger was studied over the temperature range 19-65 degrees C. A major difference between the behaviour of mono- and divalent metal ions was shown on each of the above stationary phases, with the monovalent alkali metals exhibiting clearly exothermic behaviour (a decrease in retention with increased temperature) under acidic eluent conditions and an apparent relationship between retention factor and the magnitude of the temperature effect. The effect of temperature upon alkaline earth metal ions was less defined, although strongly endothermic behaviour (increase in retention with temperature) could be seen on all stationary phases through correct choice of eluent. The transition metal ions studied showed endothermic behaviour on all four stationary phases, with the sulfonated column unexpectedly showing the largest increases in retention. The above behaviour can be partially explained through the dominance of the type of solute-stationary phase interaction governing retention. In several of the above columns, both ion-exchange and surface complexation interactions can occur, with the effects of temperature indicating which process dominates under specific eluent conditions. 相似文献
98.
Bashir A. Mansoori Edward W. Dyer Christopher M. Lock Kevin Bateman Robert K. Boyd Bruce A. Thomson 《Journal of the American Society for Mass Spectrometry》1998,9(8):775-788
The effect on triple-quadrupole performance of applying an axial field, in an rf-only quadrupole collision cell operated at pressures sufficiently high that collisional focusing is operating, has been investigated. The advantages of such cells have been shown previously to include increased transmission and much improved resolution in fragment ion spectra relative to the performance of collision cells operating at lower gas pressures. The disadvantages of high-pressure collision cells all derive from the relatively long transit times for the ions, which can be long relative to characteristic times for scanning the first mass filter (precursor ion selector) or for switching its setting in multiple reaction monitoring (MRM) cycles. The present work describes experiments on a high-pressure cell in which an axial field is created through use of conical rather than cylindrical or hyperbolic rods. In addition, results of computations of the electric fields within such a cell, and of ion trajectories through it, are presented. It is shown that application of axial fields of the order of 0. 1 V/cm can remove all hysteresis effects associated with the long ion transit times, and thus provide excellent performance in quantitation work using MRM, as well as in other scan modes. Furthermore, the advantages of collisional focusing in quadrupole collision cells are shown to be unimpaired by these low axial fields. 相似文献
99.
A flow injection spectrophotometric method is proposed for the determination of bromoxynil herbicide. Bromoxynil was hydrolyzed with HCl and the resulting product, 3,5-dibromo-4-hydroxyaniline, was diazotized with nitrite and coupled with aniline. The absorbance of the azo dye was measured at 500 nm. The conditions were optimized for diazotization using FIA. The range of linearity was found to be 0.01 to 5 ppm with a molar absorptivity of 1.27 x 10(5) L mol(-1) cm(-1). The % recovery for the determination of bromoxynil was found to be 91%. The sampling frequency was 80 samples per hour for FIA. The method is simple, fast, and has been successfully applied to the determination of bromoxynil in commercial formulations and food samples. 相似文献
100.
I. O. Abugassa S. O. Abugassa Y. S. Khrbish A. T. Bashir K. Doubali N. Ben Faid 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(3):643-646
Summary The trace elements composition of gallbladder stones samples of the types cholesterol, pigment and mixed stones in addition
to bile have been investigated by k0-instrumental neutron activation analysis (k0-INAA). The samples were obtained from several individuals of adult subjects of the Libyan population who undergone open surgery
of gallbladder (cholecystectomy) at Al-khadra University Hospital in Tripoli. The samples were lyophilized, irradiated together
with Au wire and Zr foil, which serve as flux ratio monitor and a parameter at TNRC. Concentrations of 24 elements in gallstone
and 23 elements in bile were determined. The levels of the trace elements in the various samples investigated are measured
and discussed. The reliability of the analysis was checked with several biological standard reference materials. 相似文献