Length of diagnostic tests for Boolean circuits

Mathematical Notes -     

4-hydroxy-2-quinolones 172*. Synthesis and structure of 4,3'-spiro[(6-allyl-2-amino- 5-oxo-5,6-dihydro-4h-pyrano- [3,2-<Emphasis Type="Italic">c</Emphasis>]quinoline-3-carbo- nitrile)-2'-oxindole]

A three-component condensation of 1-allyl-4-hydroxy-2-oxo-1,2-dihydroquinoline, isatin, and malononitrile gave a satisfactory yield of 4,3'-spiro[(6-allyl-2-amino-5-oxo-5,6-dihydro-4H-pyrano-[3,2-c]quinoline-3-carbonitrile)-2'-oxindole], which structure was confirmed by X-ray analysis.     

Magnetic field effects on the phonon thermal electromotive force in n-Bi-Sb semiconducting alloys

The phonon thermal electromotive force component α₂₂ (?T ‖ C ₁) prevails in n-Bi_{1 ? x} Sb_x (0.07≤x≤0.16) semiconducting alloys at low temperatures. This component increases by almost an order of magnitude in a classically strong transverse magnetic field H with H ‖ C ₃, which results in an increase in thermoelectric efficiency. The transverse Nernst-Ettingshausen coefficient Q _{12, 3} (?T ‖ C ₁, H ‖ C ₃) changes sign from negative at T > 10 K to positive at T < 10 K. The observed characteristics of the phonon thermal electromotive force and the phonon transverse Nernst-Ettingshausen coefficient are explained in terms of the theory of electron-phonon drag for electrons with a strongly anisotropic spectrum.     

Identical acyl transfer reactions between pyridine N-oxides and their N-acylonium salts

28 identical acyl exchange reactions R-CO-Nu⁺, X^? + Nu between pyridine N-oxides in acetonitrile were studied. Here, X^? = BPh ₄ ^? and R = methyl, N,N-dimethylamino, N,N-diethylamino, 4-morpholino, 1-piperidino, N-methyl, N-phenylamino, or N,N-diphenylamino group. The IR and NMR spectroscopic characteristics of acyloxypyridinium salts were determined, and the quantum-chemical parameters of all reagents calculated. The results were subjected to correlation analysis. It was found that the rate of identical acyl transfer reactions was controlled by the interaction of frontier orbitals in the transition state.     

Physicochemical properties of KF-NaF-AlF<Subscript>3</Subscript> molten electrolytes

Conductivity of molten mixtures KF-NaF-AlF₃ is measured in the whole concentration range of the [NaF]/([KF] + [NaF]) ratio at the cryolite ratio CR = 1.3 and 1.5 in the temperature range from 800°C to liquidus temperature. Replacement of K⁺ cations by Na⁺ ones results in a considerable conductivity increase. Alumina solubility rises with temperature and cryolite ratio ([KF] + [NaF])/[AlF₃] in the KF-NaF-AlF₃ system, and decreases with sodium fluoride content. Regression equations obtained allow calculating alumina solubility and electrical conductivity in the KF-NaF-AlF₃ system in the CR range from 1.3 to 3.0 depending on the concentration of the components and temperature.     

Cleavable dicationic surfactant micellar system for the decomposition of organophosphorus compounds

A dimeric (gemini) surfactant containing cleavable ester groups has been synthesized and studied. The new surfactant has a low critical micelle concentration (2.7∙10^–5 mol/L) and Krafft temperature (≤0°C). Alkaline hydrolysis of 4-nitrophenyl diethyl phosphonate and 4-nitrophenyl diethyl phosphate in the presence of micelles of gemini surfactant I proceeds 30-144 times more rapidly than in water. Chemical cleavage of gemini surfactant I in an alkaline medium is achieved in 96 h.     

Chromatography-mass spectrometry studies of transarylation and disproportionation reactions of diaryl telluroxides

Electrospray ionization chromatography-mass spectrometry was used to study transarylation and disproportionation reactions of di(4-methoxyphenyl) and di(4-dimethylaminophenyl) telluroxides in refluxing toluene. The reaction mixture compositions were established based on the mass spectrometry data and relative retention times. General schemes for fragmentation of the reaction mixture components were suggested.     

Estimation of the global stability domain in a chain of correlated phase-locked systems by the methods of image recognition theory

We formulate the problem and present the results of estimation of the global stability domain of the equilibrium state in a chain of correlated phase-locked systems by the methods of image recognition theory. This work was presented at the Summer Workshop “Dynamic Days” (Nizhny Novgorod, June 30–July 2, 1998). Lobachevsky State University of Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 12, pp. 1612–1615, December, 1998.     

Sorption Properties of a Magnetic Composite Based on Modified Carbon Nanotubes: Influence of the Synthesis Conditions

Russian Journal of Applied Chemistry - The performance of a magnetic composite sorbent consisting of magnetic nanoparticles and carbon nanotubes (CNTs) in sorption of toxic metal ions [Be(II),...     

亚临界与超临界压力水在管内的对流传热与传质

本文对含有金属腐蚀物杂质的亚临界与超临界压力水在竖直加热圆管内的受迫对流与混合对流传热与传质进行了数值模拟，分析了变物性、浮升力以及压力等因素对管内对流传热与传质的影响。结果表明：浮升力使自下而上流过竖直加热圆管的对流传热和传质增强；在不同的温度条件下，超临界压力水的热物性对传热传质的影响有很大不同。