Preparation of ion exchange membranes by plasma polymerization. I

Plasma polymerizations of three kinds of amines, γ-aminopropylethoxydimethylsilane (APEMS), allylamine (AA), and pyrole (PY), were investigated by IR and XPS analysis. Plasma-polymerized films were deposited on porous substrates, and ion exchange abilities of the composite membranes were measured. When APEMS were used as the monomer, the polymer retained the chemical structure of the monomer, amino groups. However, when AA and PY were used as the monomers, the plasma polymers contained a larger amount of amido structures than did the polymer of APEMS. Each membrane had ion exchange ability. In particular, the membrane prepared from APEMS showed superior ion exchange ability, anion permselectivity and conductivity, in acidic solutions. This property was attributed to the chemical structure of the polymer from APEMS retenting amino groups. The ion exchange properties of the membranes depended on the pH of the solution. In particular, the membrane of APEMS showed high membrane potential and low electric resistance only in a narrow pH region due to the weak basicity of amines and the hydrophobic property of the polymer.     

Volume contraction and its significance in structural formation during the thermal stabilization of acrylic fibers

The length changes of acrylic fibers during isothermal treatment at temperatures from 208°C to 270°C were measured under constant tensile stresses. In order to elucidate the relation between the length and structural changes during heat treatment, the measurements of density, the elemental composition, and the aromatization index determined from X-ray diffraction were made for the fibers heat-treated at 252°C for various periods of time. It is shown that a contraction in length which accompanied a volume contraction occurred during extended heat treatment, even when the fibers were subjected to high tensile stresses. The volume contraction is attributed to the fact that planar cyclized polymer segments, formed by additional polymerization of the nitrile side groups, are built up and construct a stacking which is denser than the original fiber structure. The orientation of the stacking of the cyclized segments was measured for the fibers heat-treated in the fixed state giving a high orientation, which is comparable to that of the fibers heat-treated under a high tensile stress giving an extension to the fibers in the initial periods of heat treatment. These results were explained by considering the interaction of external constraint and volume contraction which occurs during heat treatment.     

Radiation-induced emulsion copolymerization of tetrafluoroethylene with propylene. V. Formation of acid and its effect

In the radiation-induced emulsion copolymerization of tetrafluoroethylene with propylene, it was found that hydrofluoric acid (HF) is formed in the course of polymerization. The amount of HF formed increased linearly with the irradiation time in all cases. The rate of HF formation was maximum at 0.3 wt-% emulsifier and increased linearly with tetrafluoroethylene content in the monomer mixture. On the other hand, the conversion and the molecular weight decreased remarkably by addition of 0.1M HF. The particle diameter of copolymer obtained in the presence of HF was larger than that obtained in the HF-free system. On the contrary, the number of polymer particles was less than that obtained in the HF-free system. The decrease in the conversion and the molecular weight was attributed mainly to the conversion of part of ammonium perfluorooctanoate to perfluorooctanoic acid by formation of acid or addition of acid.     

纤维的结构和性能（Ⅲ）

本文介绍了ＰＥＴ高速纺丝纤维的热性能，低速纺丝领域中纤维的大分子取向以及纤维结晶相和非结晶相的取向，指出：纤维的沸水收缩率在纺速为２０００－３０００ｍ／ｍｉｎ内达最大值，其后随纺速增加急剧减少；纤维结晶相取向度随纺增加而增大；非晶向取向在６００ｍ／ｍｉｎ纺速以随纺速增加而增大，６０００ｍ／ｍｉｎ纺速以上随纺增加而减少。另外指出纺丝速度在７０００ｍ／ｍｉｎ以上时，ＰＥＴ纤维横断面上存在一个内部结构分     

Adsorption of oxygen in an activated europium ion-exchanged mordenite

The adsorption of oxygen in an activated europium ion-exchanged mordenite(Eu-M) was studied over the temperature range 25–600°C by the measurement of fluorescence of Eu₂₊ ion and a temperature programmed desorption (TPD) spectra of oxygen. When oxygen was exposed to a activated Eu-M, the intensity of emission band for Eu²⁺ ion extremely decreased. After the adsorption of oxygen at room temperature, the emission intensity was increased with a rise of degassing temperature and restored to the original emission intensity above 300°C. While, in Eu-M, at least four different states of adsorbed oxygen were indicated by the appearance of four TPD peaks with peak maxima located at about 70°C(α), 220°C(β), 300°C(γ) and >500°C(δ). The intensity of TPD peaks was dependent on the adsorption temperature. In the case of adsorption at 300°C or 600°C, the total amount of desorbed oxygen corresponded to one oxygen molecule adsorbing per Eu²⁺ ion.     

Permeative separation of metal ions through the polymer membrane containing gluconate group

Summary The adsorption and permeation of metal ion mixtures were examined for the membrane of poly(3-O-vinylbenzyl gluconate-co-acrylonitrile). The membrane is found to be effective for permeative separation of metal ions. For the Cu/Cd combination, especially, Cu ion was selectively adsorbed and permeated in a neutral aqueous solution. The high selectivity and the high permeation rate are discussed in connection with the chelate formation and the hydrophilicity of ion channel.     

Dissociation of associative and nonassociative concomitants of classical fear conditioning in the freely behaving rat.

In this article we describe three experiments aimed at determining why the conditioned stimulus/stimuli (CS) elicits similar increases in heart rate in groups given paired and random training. The first study demonstrates that regardless of the pseudoconditioning control procedure used (random, backwards, shock-alone, or naive), the same pattern of results is obtained: the increases in arterial pressure are greater in the paired than in each control group, but the heart rate rises to the same extent in all groups. The second study determined that the context in which the responses are tested (conditioning apparatus vs novel test chamber) does not affect the general pattern of results obtained. The third study demonstrates that the superficially similar increases in heart rate in conditioned and pseudoconditioned rats are achieved by different physiological mechanisms: coactivation of the sympathethic and parasympathetic nervous systems in conditioned rats and sympathetic excitation alone in pseudoconditioned rats. Thus, the heart is influenced by associative emotional processes, but heart rate is not, under these conditions, a particularly useful index of those influences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of Insect Cuticular Hydrocarbons Using Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

Insect cuticular hydrocarbons (CHCs) were probed by matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) mass spectrometry with a lithium 2,5-dihydroxybenzoate matrix. CHC profiles were obtained for 12 species of diverse insect taxa (termites, ants, a cockroach, and a flesh fly). MALDI spectra revealed the presence of high molecular weight CHCs on the insect cuticle. Hydrocarbons with more than 70 carbon atoms, both saturated and unsaturated, were detected. When compared with gas chromatography/mass spectrometry (GC/MS), MALDI-TOF covered a wider range of CHCs and enabled CHCs of considerably higher molecular weight to be detected. Good congruity between GC/MS and MALDI-TOF was observed in the overlapping region of molecular weights. Moreover, a number of previously undiscovered hydrocarbons were detected in the high mass range beyond the analytical capabilities of current GC/MS instruments. MALDI was shown to hold potential to become an alternative analytical method for insect CHC analyses. The ability of MALDI to discriminate among species varying in the degree of their relatedness was found to be similar to GC/MS. However, neither MALDI-MS nor GC/MS data were able to describe the phylogenetic relationships.     

Adaptive Fault Diagnosis of Analog Circuits by Operation-Region Model and X–Y Zoning Method

We have proposed a method for diagnosing analog circuits that is realized by combining the operation-region model and the X–Y zoning method. In the method, we could implement a diagnosis procedure based on a diagnostic method for digital circuits because we developed a data processing method to handle data discretely. In this paper, we improve the method by using an adaptive test to obtain a shorter diagnostic sequence length and show its characteristics. Moreover, we propose a new data processing method that utilizes the output response of a circuit to obtain better diagnostic performance. We demonstrate the effectiveness of the proposed methods by applying them to ITC’97 benchmark circuits with hard faults and soft faults. These improved methods can reduce the diagnostic sequence length without degrading the performance of diagnostic resolution and CPU time.