Transport properties of cellulose ester membranes for separating gas and liquid mixtures

Mass-exchange characteristics of cellulose myristate or acetomyristate membranes in separating aqueous-organic, organic, or gas mixtures, particularly, in recovering aromatic hydrocarbons from binary mixtures with aliphatic alcohols, and also ethyl acetate from a mixture of esterification products, are studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 11, 2004, pp. 1895–1900.Original Russian Text Copyright © 2004 by Yu. Kuznetsov, Khripunov, Kruchinina, V. Kuznetsov, Turkova, Penkova.     

Effect of the drilling mud filtrate temperature on the resistivity of the stratum saturated by oil and gas

A mathematical model of the axisymmetric distribution of the phases in the zone of invasion of the water-based drilling mud into the productive stratum whose porous space can simultaneously contain three immiscible fluids (oil, gas, and natural water) is constructed; the model takes into account the high rate of heat transfer between the fluids and the rock matrix. It is shown that the resistivity of the invaded zone depends not only on saturation of the latter by the fluids and the concentration of salts in the water phase, but also on the drilling mud filtrate temperature. It is also shown that there is a jump in the function of stratum saturation by oil on the thermal front.     

Structure‐Based Design and Synthesis of Regioisomeric Disubstituted Aminoanthraquinone Derivatives as Potential Anticancer Agents

Continuing our ongoing studies on cytotoxic substances, we report the synthesis and cytotoxic properties of a series of symmetric 1,5‐diamino‐9,10‐anthraquinones with potentially bioreducible groups. Symmetric amination of 1,5‐dichloro‐9,10‐anthraquinone with the appropriate primary amines in the presence of DMF furnished the structurally related aminoanthraquinone analogs 1 – 19 . Their in vitro cytotoxic activity was evaluated using rat glioma C6 cells, human hepatoma G2 cells, and 2.2.15 cells. Several compounds exhibited very high antitumor activities in these assays. Compound 4 efficiently inhibited C6 cells, human hepatoma G2 cells, and 2.2.15 cells, as determined by means of the XTT colorimetric assay. The antiproliferative activity of 4 was markedly enhanced, reaching a potency comparable to those of the powerful anticancer agents mitoxantrone, adriamycin, and cisplatin. Biological evaluations and structure/activity relationships within this class of novel aminoanthraquinones are discussed.     

The propagation of shock waves in anisotropic materials

The propagation of shock waves in anisotropic materials (aluminium alloys), the state of which obeys a non-linear relation, which generalizes Grüneisen's equation for isotropic materials, is investigated. The concept of total generalized pressure and the pressure corresponding to the thermodynamic response is proposed. A modification of the anisotropic Hill criterion in the case of non-associated plastic flow, for which the yield surface is independent of the generalized hydrostatic stress, is considered.     

Electrodeposition of cadmium telluride from electrolytes based on ethylene glycol

Electrochemical behavior of cadmium and tellurium ions in their joint reduction on a glassy carbon electrode in a nonaqueous electrolyte based on ethylene glycol was studied. An X-ray phase analysis and transmission electron microscopy were used to determine the phase composition and particle size of the electrodeposited CdTe films.     

Enhanced stability of Pt electrocatalysts by nitrogen doping in CNTs for PEM fuel cells

Electrochemical stabilities of Pt deposited on carbon nanotubes (CNTs) and nitrogen-doped carbon nanotubes (CN_x) of different nitrogen contents are compared with accelerated durability tests (ADT) for the first time. Transmission electron microscopy (TEM) images reveal the different structures of CNTs and CN_x, and the decrease of Pt particle size with the nitrogen incorporation into CNTs. Based on the loss of electrochemical surface area (ESA) and TEM images, Pt/CN_x exhibited much higher stability than Pt/CNTs, and the Pt stability increases with the increase of nitrogen contents in the CN_x supports.     

New Benzofuranylpropanoids from the Roots of Codonopsis lanceolata

Three new benzofuranylpropanoids, lanceolunes A–C ( 1 – 3 ), were isolated from the roots of Codonopsis lanceolata. Their structures were determined by means of HR‐ESI‐MS, extensive 1D‐ and 2D‐NMR spectroscopic, and chemical evidence.     

Kinetic study of the 1,3,5-triphenyl-Δ2-pyrazoline/technetium(VII) system: Determination of Technetium

The interaction of technetium with 1,3,5-triphenyl-Δ²-pyrazoline (TPP) is examined and kinetic methods for the determination of technetium (0.01–1.2 mg l^?1) are developed; absorbances are measured at 678 nm. The optimal hydrochloric acid concentration for the reaction is 8.3 M, with a TPP concentration of 6.6 × 10^?5 M in 15 % (v/v) ethanol. Interferences by Cu(II), V(V) and Fe(III) are discussed. The method is applied to two synthetic nuclear fuels and to vegetation spiked with technetium.     

一种新型谱分析仪的设计

本文介绍了基于过零检测谱分析仪的基本原理,讨论了它的工程实现及有关技术指标。这种谱仪回避了A/D转换器的限制,是信号谱估计的一种新理论和新技术。