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101.
102.
Conducting polymer composites of polyvinylferrocene and polypyrrole (PVF/PPy) were synthesized chemically by the in situ polymerization of pyrrole in the presence of PVF using FeCl3 as oxidant. Acetic (CH3COOH) and boric (H3BO3) acids were used as the synthesis medium. Effects of the synthesis medium on the properties of the PVF/PPy composite were investigated. The PVF/PPy composites and homopolymers were characterized by fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and magnetic susceptibility techniques. Conductivity measurements were performed using the four‐probe technique. We found that the conductivities of PVF/PPy‐H3BO3 (1.19 S cm?1) and PVF/PPy‐CH3COOH (4.5×10?1 S cm?1) increased relative to those of the homopolymers of PPy‐H3BO3 (2.1×10?2 S cm?1) and PPy‐CH3COOH (1.2×10?2 S cm?1) due to the interaction of PVF with the pyrrole moiety. The stability of all homopolymers and composites were investigated by thermogravimetric analysis and by conductivity measurements during heating‐cooling cycles. There was a small drop in conductivity caused by the annealing of PVF/PPy composites at 70°C. The conductivity of all samples increased with temperature and exhibited stable electrical behavior with increasing temperature. TGA analysis of samples showed that the composites were more stable than the homopolymers or PVF separately. The magnetic susceptibility values of samples were negative, except for PVF/PPy‐H3BO3. Morphology changes of the composites investigated by scanning electron microscopy (SEM), attributed to synthesis conditions, have a significant effect on their conductivity. 相似文献
103.
Halil Güler Figen Kurtuluş İmdat Kadan Ayşe Morkan Sebahat Akin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1371-1379
In this study, the sulfidization of Na2CO3 was investigated by using a solid-gas reaction under a sulfidizing gas mixture, which consisted of COS, CS2, and S2 gases. Sodium sulfide pentahydrate, Na2S·5H2O, was prepared from sodium carbonate, Na2CO3, via a sulfidizing gas mixture by a solid-gas reaction under the cooling of a nitrogen atmosphere. The observed phase was found to be the pentahydrated form of sodium sulfide. This crystalline form was determined by X-ray powder diffraction (XRD) technique. Since sodium sulfide is strongly hygroscopic, the pentahydrated crystalline form was observed in XRD measurements for all repeated experiments. The crystal unit cell parameters of the synthesized product were in excellent agreement with values given in the JCPDS card number 18-1249. The sodium sulfide pentahydrate has an orthorhombic crystal structure with the unit cell parameters of a = 6.475, b = 12.55, C = 8.655 Å, space group, Cmcm and Z = 4. 相似文献
104.
In all but special circumstances, measurements of time-dependent processes reflect internal structures and correlations only
indirectly. Building predictive models of such hidden information sources requires discovering, in some way, the internal
states and mechanisms. Unfortunately, there are often many possible models that are observationally equivalent. Here we show
that the situation is not as arbitrary as one would think. We show that generators of hidden stochastic processes can be reduced
to a minimal form and compare this reduced representation to that provided by computational mechanics – the ε-machine. On
the way to developing deeper, measure-theoretic foundations for the latter, we introduce a new two-step reduction process.
The first step (internal-event reduction) produces the smallest observationally equivalent σ-algebra and the second (internal-state
reduction) removes σ-algebra components that are redundant for optimal prediction. For several classes of stochastic dynamical
systems these reductions produce representations that are equivalent to ε-machines. 相似文献
105.
The influence of Ca-Montmorillonite (Ca-MNT) and zeolite NaY addition on ethanol production from synthetic molasses by S. cerevisiae 251 TP(3-2) was studied by the measurement of biomass concentrations and metal ion concentration with respect to fermentation
time. Addition of 5 g/L Ca-MNT and 10 g/L zeolite NaY resulted in an increase in both ethanol concentration and ethanol production
rate. This increase was 24 and 40% for ethanol concentration and 65 and 87% for production rate, respectively. From the ion
analyses, it was observed that the NaY added to the medium decreased the toxic concentration of zinc, manganese, and iron
cations and acted also as a pH regulator. Ca-MNT added to the medium decreased the concentration of Na+ ions, which is known to have a toxic effect on glycolysis and cell concentration. These effects caused improvement in the
ethanol production rate. 相似文献
106.
In the scope of achieving the separation of chiral molecules, enzyme enhanced ultrafiltration (EEUF), a new method based on polymer enhanced ultrafiltration (PEUF), utilizing apoenzymes as ligands, was developed. Benzoin was chosen as the model chiral molecule. Bovine serum albumin (BSA) and apo form of benzaldehyde lyase (BAL) (E.C. 4.1.2.38) were used as chiral ligands in PEUF and EEUF experiments, respectively. In order to bind to the target enantiomer well, the addition of ligand to the benzoin solution was followed by ultrafiltration. With the use of BSA as ligand, adaptation of PEUF for chiral target molecules and process parameter optimization was carried out; whereas, in EEUF studies the effect of ligand concentration was focused on. In PEUF experiments, although total benzoin retention values reached to 48.7% and 41.3% at pH 10, for 15% (v/v) PEG 400 and 30% (v/v) DMSO cosolvents, respectively; obtained enantiomeric excess (ee) % values were all less than 20%. In EEUF experiments, at BAL concentrations greater than 158 ppm, total benzoin retention and ee% remained constant at ca. 75% and 60%, respectively. On the other hand, at 61 ppm BAL concentration, total benzoin retention was kept at ca. 75%, but ee% decreased to ca. 30%, probably due to the nonspecific binding of benzoin to DNA and other proteins. Thus, the method developed enzyme enhanced ultrafiltration, functioned with its intended purpose effectively in chiral separation. 相似文献
107.
Composites of polyfuran (PFu) with LTA type (3A, 4A, 5A) zeolites were prepared via chemical oxidative polymerization of furan (Fu) in the presence of a dispersion of zeolites (powder) in ACN solvent using anhydrous FeCl3 oxidant at an ambient temperature. The composites were characterized by Fourier transform infrared spectroscopic (FTIR) analysis. FTIR results showed that the composites of 3A zeolite with the smallest pore size did not indicate absorption for benzoyl chloride due to surface structural of OH groups. Thermogravimetric analysis revealed the stability order as: 3A > PFu/3A > PFu, 4A > PFu/4A > PFu, 5A > PFu/5A > PFu. Scanning electron microscopic analysis and X-ray diffraction analysis indicated the formation of polyfuran on zeolite structures. Conductivity values of samples are in the range of semi conductors. 相似文献
108.
In this study, single-stage and two-phase semi-continuous thermophilic anaerobic reactors fed with diluted (3 % total solids (TS) and 1.8 % volatile solids (VS)) chicken manure at three different hydraulic retention times (HRTs) were compared interms of biogas production rate, methane content of the produced biogas, and VS and TS removal. Along the study, HRTs of 16, 12, and 8 days were implemented to the single-stage and the two-phase systems. It was observed that the single-stage anaerobic system was superior to the two-phase anaerobic system according to their biogas production rates (517 vs. 356, 551 vs. 359, 459 vs. 386 (mL/g VSfeed)) at all HRTs. On the other hand, methane content of the biogas produced was higher in the two-phase system compared to the single-stage system. 相似文献
109.
In our study, we integrate the data uncertainty of real-world models into our regulatory systems and robustify them. We newly introduce and analyse robust time-discrete target–environment regulatory systems under polyhedral uncertainty through robust optimization. Robust optimization has reached a great importance as a modelling framework for immunizing against parametric uncertainties and the integration of uncertain data is of considerable importance for the model’s reliability of a highly interconnected system. Then, we present a numerical example to demonstrate the efficiency of our new robust regression method for regulatory networks. The results indicate that our approach can successfully approximate the target–environment interaction, based on the expression values of all targets and environmental factors. 相似文献
110.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Aguilo E Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Ancu LS Andeen T Anderson S Andrieu B Anzelc MS Arnoud Y Arov M Askew A Asman B Assis Jesus AC Atramentov O Autermann C Avila C Ay C Badaud F Baden A Bagby L Baldin B Bandurin DV Banerjee P Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Beale S Bean A Begalli M Begel M Belanger-Champagne C Bellantoni L 《Physical review letters》2007,98(15):151801
We have performed the first direct measurement of the time-integrated flavor untagged charge asymmetry in semileptonic Bs0 decays ASLs,unt by comparing the decay rate of Bs0-->micro+Ds-nuX, where Ds- -->phipi- and phi-->K+K-, with the charge-conjugate Bs0 decay rate. This sample was selected from 1.3 fb-1 of data collected by the D0 experiment in run II of the Fermilab Tevatron collider. We obtain ASLs,unt=[1.23+/-0.97(stat)+/-0.17(syst)]x10(-2). Assuming that Deltam(s)/Gamma(s)>1, this result can be translated into a measurement of the CP-violating phase in Bs0 mixing: DeltaGamma(s)/Deltam(s)tanphi(s)=[2.45+/-1.93(stat)+/-0.35(syst)]x10(-2). 相似文献