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101.
102.
The exchange currents of Ag/AgNO_3-NH_3 electrode systems were measured by using radiotrcer method.The magnitude of exchange currents was obtained to be of the order 10~(-7) A. cm~(-2) in solutions with various concentrations of Ag~+(Ⅰ). The data show that the exchange currents decrease with reduction in Ag~+ (Ⅰ) concen- trations.However the difference of exchange currents is not significant.It is in coincidance with the assumption that in very low overpotential region the surface diffusion of adatom is the rate determining step.The experimental conditions that must be fulfilled in order to ensure successful application of this method were also discussed. 相似文献
103.
Vyhnalkova R Eisenberg A van de Ven TG 《Langmuir : the ACS journal of surfaces and colloids》2011,27(18):11296-11305
Biocide emulsions stabilized with various stabilizing agents were prepared and characterized, and their efficiency in bacteria deactivation was evaluated. A number of stabilizing agents were tested for their stabilizing effect on emulsions of thiocyanomethylthiobenzothiazole (TCMTB) biocide. Two agents, the most successful in stabilizing the biocide, were chosen for further studies: high molecular weight polyethyleneimine (PEI) and an amphiphilic block copolymer of poly(caprolactone)-b-poly(acrylic acid) (PCL(33)-b-PAA(33)). The emulsion droplet sizes varied between 325 and 500 nm. Deactivation of bacteria was studied by exposing E. coli ATCC 11229 bacteria dispersions to emulsions stabilized by positively charged PEI or negatively charged PCL-b-PAA micelles and by measuring their absorbance; E. coli do not grow with time in the presence of biocide emulsions. PEI molecules alone act as biocide and deactivate the bacteria. PCL-b-PAA micelles as stabilizing agent do not affect the growth of the E. coli ; bacteria are deactivated by TCMTB released from the emulsion droplets. The kinetics of emulsion dissolution studies revealed for both stabilizing agents a decrease in droplet size with time while the emulsions were subjected to dialysis. The biocide was released from the emulsions within ~250 min; the droplet shells consist mostly of PEI or PCL-b-PAA insoluble complexes with the biocide, which do not dissolve during dialysis. SEM images confirm the presence of residual crumbled shells with holes after 24 h of dialysis. 相似文献
104.
Kiki Adi Kurnia B. Ariwahjoedi M. I. Abdul Mutalib T. Murugesan 《Journal of solution chemistry》2011,40(3):470-480
Densities were determined for binary mixtures containing the protic ionic liquid bis(2-hydroxyethyl)ammonium acetate [BHEAA] and an alcohol (methanol, ethanol, and 1-propanol) at four different temperatures (293.15, 303.15, 313.15, and 323.15) K and ambient pressure. Coefficients of thermal expansion and excess molar volumes were calculated from the experimental densities. The excess molar volumes were fitted using the Redlich-Kister polynomial equation. Negative deviations from ideal behavior of the excess molar volume were observed for all systems investigated in this study. The results were interpreted in terms of ion-dipole interactions and structural factors of the ionic liquid and alcohol. It was observed that an increase of the alcohol carbon chain length led to lower interactions on mixing. 相似文献
105.
106.
The stability of a quantum model of a c.w. laser is demonstrated using Lyapounov's second method. 相似文献
107.
Zero-knowledge proofs of identity 总被引:25,自引:2,他引:23
In this paper we extend the notion of interactive proofs of assertions to interactive proofs of knowledge. This leads to the
definition of unrestricted input zero-knowledge proofs of knowledge in which the prover demonstrates possession of knowledge
without revealing any computational information whatsoever (not even the one bit revealed in zero-knowledge proofs of assertions).
We show the relevance of these notions to identification schemes, in which parties prove their identity by demonstrating their
knowledge rather than by proving the validity of assertions. We describe a novel scheme which is provably secure if factoring
is difficult and whose practical implementations are about two orders of magnitude faster than RSA-based identification schemes.
The advantages of thinking in terms of proofs of knowledge rather than proofs of assertions are demonstrated in two efficient
variants of the scheme: unrestricted input zero-knowledge proofs of knowledge are used in the construction of a scheme which
needs no directory; a version of the scheme based on parallel interactive proofs (which are not known to be zero knowledge)
is proved secure by observing that the identification protocols are proofs of knowledge. 相似文献
108.
Specular reflectance changes have been used to examine the specific adsorption of bromide on gold in the presence of a large excess of supporting electrolyte (NaF) which is not specifically adsorbed. A linear relation has been demonstrated between the reflectance changes and the surface excess of bromide through the examination of the time dependence of the reflectance under conditions where the rate of adsorption of the bromide is diffusion controlled and hence known. The adsorption isotherms have been found to follow Temkin behavior. The electrosorption valency has been evaluated from the charge and surface excess at constant potential and found to be ?0.49 to ?0.59, depending on the potential. Various mechanisms for the subtantial changes in reflectance attending the specific adsorption of anions are discussed. The observed effects cannot be explained on the basis of changes in the charge on the electrode and corresponding changes in the contribution of the conduction band to the surface optical properties. The principal mechanism is proposed to be modifications in the surface electronic states of the metal electrode through direct orbital interactions between the adsorbed anions and the metal. 相似文献
109.
Dr. Ashim Paul Adi Huber Daniel Rand Prof. Fabien Gosselet Prof. Itzik Cooper Prof. Ehud Gazit Prof. Daniel Segal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(69):16486-16496
Accumulation and aggregation of the intrinsically disordered protein α-synuclein (α-Syn) into amyloid fibrils are hallmarks of a series of heterogeneous neurodegenerative disorders, known as synucleinopathies and most notably Parkinson's disease (PD). The crucial role of α-Syn aggregation in PD makes it an attractive target for the development of disease-modifying therapeutics that would inhibit α-Syn aggregation or disrupt its preformed fibrillar assemblies. To this end, we have designed and synthesized two naphthoquinone–dopamine-based hybrid small molecules, NQDA and Cl-NQDA, and demonstrated their ability to inhibit in vitro amyloid formation by α-Syn using ThT assay, CD, TEM, and Congo red birefringence. Moreover, these hybrid molecules efficiently disassembled preformed fibrils of α-Syn into nontoxic species, as evident from LUV leakage assay. NQDA and Cl-NQDA were found to have low cytotoxicity and they attenuated the toxicity induced by α-Syn towards SH-SY5Y neuroblastoma cells. NQDA was found to efficiently cross an in vitro human blood–brain barrier model. These naphthoquinone–dopamine based derivatives can be an attractive scaffold for therapeutic design towards PD. 相似文献
110.
The least (Euclidean-) norm solution of a consistent linear equation Ax = b is given a determinantal form, which reduces to Cramer's rule if A is nonsingular. 相似文献