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21.
Binary mixtures of ethylene glycols HO(CH2CH2O)xH (x = 3–5) with glycerol were investigated by fast atom bombardment mass Spectrometry. The relative intensities in the ethylene glycol partial mass spectra as a function of concentration exhibit a steep slope in the low concentration range. With increasing concentration the curves asymptotically approach the 100% line. This effect increases from triethylene to pentaethylene glycol. Comparison of these results with those of surface tension measurements leads to the conclusion that the high sensitivity of fast atom bombardment mass Spectrometry for ethylene glycols is caused by the surface-active properties of these compounds, which lead to an enrichment of the surface investigated with the substance molecules. 相似文献
22.
We discuss two types of ideals of rings of continuous real-valued functions on completely regular frames. The first are those which with every element they contain, they also contain the double annihilator of the element; and the second are those which for any two elements which are contained in exactly the same set of maximal ideals, they either contain both elements or miss both elements. We show that, in both cases, sending a frame to the lattice of these ideals is a functorial assignment. We construct a natural transformation between the functors that arise from these assignments. Frame maps do not always have left adjoints. We show that, for a certain collection of frame maps, the functor associated with the second type of ideals preserves and reflects the property of having a left adjoint. 相似文献
23.
Themba Dube Inderasan Naidoo 《Topology and its Applications》2011,158(16):2257-2259
We address and correct an oversight that we have identified in Lemma 3.2 of Dube and Naidoo (2010) [2] and provide counterexamples to the original assertions. 相似文献
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A frame homomorphism is coz-onto if it maps the cozero part of its domain surjectively onto that of its codomain. This captures the notion of a z-embedded subspace of a topological space in a point-free setting. We give three different types of characterizations of coz-onto homomorphisms. The first is in terms of elements, the second in terms of quotients, and the last in terms of ideals. As an application of properties of coz-onto homomorphisms developed herein, we present some characterizations of $F$ - and $F^{\prime }$ -frames. 相似文献
26.
Debabrata Chatterjee Namita Jaiswal Jagadeesh C. Bose K Ram Balak Mahato Diptendu Bhattacharyya 《Journal of Coordination Chemistry》2015,68(17-18):3229-3235
Reaction of [RuIII(EDTA)(CyS)]2? (edta4? = ethylenediaminetetraacetate; CySH = cysteine) with molecular oxygen (O2) has been studied as a function of pH (4.0–8.0) and cysteine concentration (0.2–2.0 mM) at room temperature (25 °C). Biological activities of the [Ru(EDTA)]/CySH/O2 system pertaining to cleavage of supercoiled plasmid DNA to its nicked open circular form has been explored in this work. Results are discussed in regard to the reaction of the ruthenium(III)-complex with molecular oxygen) and a working mechanism is proposed for the biological activities of the ruthenium(III)-complex in the presence of O2. 相似文献
27.
We study three types of quotient maps of frames which are closely related to C- and C?-quotient maps. We call them C1-, strong C1-, and uplifting quotient maps. C1-quotient maps are precisely those whose induced ring homomorphisms contract maximal ideals to maximal ideals. We show that every homomorphism onto a frame is a C1-, a strong C1-, or an uplifting quotient map iff the frame is pseudocompact, compact, or almost compact and normal, respectively. These quotient maps are used to characterize normality and also certain weaker forms of normality in a manner akin to the characterization of normal frames as those for which every closed quotient map is a C-quotient map. Under certain conditions, we show that the Stone extension of a quotient map is C1-, strongly C1- or uplifting if the map has the corresponding property. 相似文献
28.
Yu X Mailman A Dube PA Assoud A Oakley RT 《Chemical communications (Cambridge, England)》2011,47(16):4655-4657
The alternating ABABAB π-stacked bis-1,2,3-dithiazolyl radical 2a (2, R(2)=Ph) has a conductivity σ of 3×10(-5) S cm(-1) at 300 K, and orders as a spin-canted antiferromagnet (T(N)=4.5 K) which undergoes a spin-flop transition to a field-induced ferromagnetic state saturating (at 2 K) at H ~20 kOe. 相似文献
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