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111.
The eluent strengths of para, ortho and meta substituted hydroxy-, nitro-, amino- and sulfobenzoic acids in single column ion chromatographic separations of inorganic and organic anions have been evaluated and compared with benzoic acid.o-Sulfobenzoic acid turns out to be a stronger and efficient eluent compared to others for the separation and determination of monovalent (Cl–, NO
2
–
, Br–, NO
3
–
) and divalent (SO
4
2–
, SeO
4
2–
, S2O
3
2–
, S2O
6
2–
) inorganic anions. In addition it also functions as an appropriate mobile phase for the detection and quantification of some substituted benzoate ions in an aqueous medium. 相似文献
112.
Summary A method is described for the determination of mercaptans by alkalimetric titration of trithiocarbonic acids formed through their reaction with carbon disulphide in tert.-butanol. The method has been applied to the analysis, on the same sample solution, of mixtures of mercaptans containing titrable hydrogen and those containing nontitrable hydrogen, mercaptans and alkali mercaptides, and mercaptans and mercaptopyrimidines.
Analytische Anwendung der Merkaptan-Schwefelkohlenstoff-Reaktion: Bestimmung von Merkaptan in Gemischen
Zusammenfassung Ein Verfahren zur Merkaptanbestimmung durch alkalimetrische Titration der Trithiokohlensäure auf der Grundlage seiner Reaktion mit Schwefelkohlenstoff in tert. Butanol wurde beschrieben. Es eignet sich zur Bestimmung von Gemischen aus Merkaptanen mit titrierbarem Wasserstoff und solchen ohne titrierbaren Wasserstoff sowie von Merkaptanen und Merkaptiden, weiters von Merkaptanen und Merkaptopyrimidinen.相似文献
113.
Oscillations in a Belousov-Zhabotinskii (B-Z) system having oxalic acid (OA) and glucose (G) as a mixed organic substrate, neither of which acts as a bromine scavenger, have been investigated. Studies have been performed for (i) varying the concentration of G while keeping the OA concentration fixed and (ii) varying OA but keeping G fixed in a batch reactor. In both cases upper and lower critical limits occur, between which oscillations are observed. Both single and double frequency oscillations have been observed in a wide range of concentrations of G as well as of OA. The induction period in most of the cases was <1 min. When G is fixed and OA is varied, the time pause between the sequential oscillations increases with an increase in OA. On the other hand when OA is fixed and G is varied, the time-pause decreases with an increase in G. The first type of oscillation is Br(-)-controlled, whereas the second is non-Br(-)-controlled. The order of addition of G and OA in the last has no influence on the induction period. It influences, however, the oscillatory characteristics. Br(2) evolution in the G + OA + Ce(4+) + BrO(3)(-) + H(2)SO(4) reaction system has been investigated spectrophotometrically. ESR and polymerization studies indicate the important role of free radicals in influencing the reaction mechanism. A tentative dual control mechanism has been suggested involving autocatalysis of HBrO(2) and BrO2*. 相似文献
114.
Generalization of five q-series identities of Ramanujan and unexplored weighted partition identities
The Ramanujan Journal - Ramanujan recorded five interesting q-series identities in a section that is not as systematically arranged as the other chapters of his second notebook. These five... 相似文献
115.
Sensing response of ‘self-binding’ nanoparticles of tin dioxide powder deposited on alumina substrate has been investigated. The nanocrystalline SnO2 powder has been derived from stannic chloride. It has been prepared through fine crystallization in liquid phase. SnO2 powder has been characterized using SEM, TEM and XRD techniques, which reveal that the average crystallite size is of 12 nm. The slurry blobs deposited on alumina substrate of the powder-thus-prepared have been studied for sensing response to ethanol at various temperatures and concentrations. The observations reveal that the material prepared is ‘self-binding’ and is very sensitive even without catalyst. 相似文献
116.
Depolarization behaviour of vacuum deposited polyvinyl fluoride (PVF) films has been studied as a function of nature of the
electrode materials used during polarization such as copper, silver, aluminium and indium using the thermally stimulated discharge
current (TSD) technique. TSD spectra of these films show a single relaxation peak centered around 430 ± 1 K with activation
energies of ∼ 0.65 eV. The peak current and the charge associated with the relaxation peak depend strongly on the electrode
material used. This has been attributed to the electrode-polymer interface barrier controlling the injection of the charge
carriers into PVF films that results into space charge effects by subsequent trapping of the injected charge carriers at macroscopic
distances.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献
117.
An attempt has been made in the present work to combine gel and composite polymer electrolyte routes together to form a composite
polymeric gel electrolyte that is expected to possess high ionic conductivity with good mechanical integrity. Polyethylene
glycol (PEG) based composite gel electrolytes using polyvinyl alcohol (PVA) as guest polymer have been synthesized with 1
molar solution of ammonium thiocyanate (NH4SCN) in dimethyl sulphoxide (DMSO) and electrically characterized. The ionic conductivity measurements indicate that PEG:PVA:NH4SCN-based composite gel electrolytes are superior (σ
max = 5.7 × 10−2 S cm−1) to pristine electrolytes (PEG:NH4SCN system) and conductivity variation with filler concentration remains within an order of magnitude. The observed conductivity
maxima have been correlated to PEG:PVA:NH4SCN-and PVA:NH4SCN-type complexes. Temperature dependence of conductivity profiles exhibits Arrhenius behaviour in low temperature regime
followed by VTF character at higher temperature.
相似文献
118.
Adler SS Afanasiev S Aidala C Ajitanand NN Akiba Y Alexander J Amirikas R Aphecetche L Aronson SH Averbeck R Awes TC Azmoun R Babintsev V Baldisseri A Barish KN Barnes PD Bassalleck B Bathe S Batsouli S Baublis V Bazilevsky A Belikov S Berdnikov Y Bhagavatula S Boissevain JG Borel H Borenstein S Brooks ML Brown DS Bruner N Bucher D Buesching H Bumazhnov V Bunce G Burward-Hoy JM Butsyk S Camard X Chai JS Chand P Chang WC Chernichenko S Chi CY Chiba J Chiu M Choi IJ Choi J Choudhury RK Chujo T 《Physical review letters》2004,92(5):051802
J/psi production has been measured in proton-proton collisions at square root of s=200 GeV over a wide rapidity and transverse momentum range by the PHENIX experiment at the Relativistic Heavy Ion Collider. Distributions of the rapidity and transverse momentum, along with measurements of the mean transverse momentum and total production cross section are presented and compared to available theoretical calculations. The total J/psi cross section is 4.0+/-0.6(stat)+/-0.6(syst)+/-0.4(abs) mu b. The mean transverse momentum is 1.80+/-0.23(stat)+/-0.16(syst) GeV/c. 相似文献
119.
Adler SS Afanasiev S Aidala C Ajitanand NN Akiba Y Al-Jamel A Alexander J Aoki K Aphecetche L Armendariz R Aronson SH Averbeck R Awes TC Babintsev V Baldisseri A Barish KN Barnes PD Bassalleck B Bathe S Batsouli S Baublis V Bauer F Bazilevsky A Belikov S Bjorndal MT Boissevain JG Borel H Brooks ML Brown DS Bruner N Bucher D Buesching H Bumazhnov V Bunce G Burward-Hoy JM Butsyk S Camard X Chand P Chang WC Chernichenko S Chi CY Chiba J Chiu M Choi IJ Choudhury RK Chujo T Cianciolo V Cobigo Y 《Physical review letters》2003,91(7):072303
Transverse momentum spectra of charged hadrons with p(T)<8 GeV/c and neutral pions with p(T)<10 GeV/c have been measured at midrapidity by the PHENIX experiment at BNL RHIC in d+Au collisions at sqrt[s(NN)]=200 GeV. The measured yields are compared to those in p+p collisions at the same sqrt[s(NN)] scaled up by the number of underlying nucleon-nucleon collisions in d+Au. The yield ratio does not show the suppression observed in central Au+Au collisions at RHIC. Instead, there is a small enhancement in the yield of high momentum particles. 相似文献
120.
Adler SS Afanasiev S Aidala C Ajitanand NN Akiba Y Alexander J Amirikas R Aphecetche L Aronson SH Averbeck R Awes TC Azmoun R Babintsev V Baldisseri A Barish KN Barnes PD Bassalleck B Bathe S Batsouli S Baublis V Bazilevsky A Belikov S Berdnikov Y Bhagavatula S Boissevain JG Borel H Borenstein S Brooks ML Brown DS Bruner N Bucher D Buesching H Bumazhnov V Bunce G Burward-Hoy JM Butsyk S Camard X Chai JS Chand P Chang WC Chernichenko S Chi CY Chiba J Chiu M Choi IJ Choi J Choudhury RK Chujo T 《Physical review letters》2003,91(7):072301
Transverse momentum spectra of neutral pions in the range 1
相似文献