Innovative stabilization/solidification processes of fly ash from an incinerator plant of urban solid waste

Fly ash samples from an incineration plant of urban solid waste (USW) were submitted to a stabilization/solidification process based on encapsulation with a polyester resin. With this process, a very limited increase of about 25% in weight and a compressive strength as high as 1200 kg/cm² can be obtained. The efficiency of the process to stabilize/solidify the residues and to reduce the pollutant release was evaluated by performing both mechanical and leaching tests following the IRSA–CNR standard method. The leaching test was based on treating the sample with an acetic acid solution adjusted to pH 5.2 for 24 h under magnetic stirring. Toxic metals (Pb, Cd, and Cu) and organic pollutants (PAHs, PCBs, and OCPs) were determined in raw fly ash samples and in the leaching solutions of treated samples. Raw residues showed higher concentrations of trace metals than the regulatory limits, whereas the stabilized/solidified residues showed a concentration of all the pollutants lower than the regulatory limits and a compressive strength much higher than the suggested minimum value. Finally, a critical comparison with conventional stabilization/solidification processes based on the use of Portland cement highlighted that the polyester resin-based process performed much better in terms of the release of both organic and inorganic pollutants, thus substantially lowering the environmental impact of these residues.     

Shock-wave and conventional deformation of Al and dispersion-hardened Al alloy containing different concentrations of alumina particles

Summary The structure and substructure changes in Al and dispersion-hardened Al alloy are studied after rapid deformation by explosion and slow conventional deformation (cross-rolling and compression) using X-ray diffraction analysis and transmission electron microscopy. Shock wave deformation generates a small dislocation density which does not produce any significant change in the microstructure as well as in the texture of Al and Al alloy containing a different concentration of Al₂O₃ particles (4 and 7%). After slow conventional deformation, in particular after cross-rolling, significant variations are observed due to the nonuniformly distributed high dislocation densities.     

数学建模与聚类分析方法在企业经营效绩评价中的综合运用

本论文通过CT总公司所属九个分公司财务指标即:财务效益状况指标,资产营运状况指标,偿债能力状况指标,发展能力状况指标和稳固程度状况指标五个方面的财务状况数据,一方面采用数理统计方法进行数据分析,建立数学模型,设定了评分办法及评分标准.做出了CT总公司所属九个分公司2 0 0 0年的经营业绩(量化)评价结果.另一方面按九个公司财务指标的原始数据用聚类分析的方法将其归类,进一步揭示出各个公司之间的联系与差别.     

Facile method to prepare monodispersed Ag/polystyrene composite microspheres and their properties

This article presents a facile method to prepare silver/polystyrene composite microspheres. In this approach, monodispersed polystyrene (PS) particles were synthesized with carboxyl acid groups on the surfaces of the PS particles via dispersion polymerization at first. With the addition of [Ag(NH₃)₂]⁺ to the PS dispersion, [Ag(NH₃)₂]⁺ was absorbed to the surfaces of the PS particles, and then by heating the system, [Ag(NH₃)₂]⁺ complex ions were reduced to silver to form the Ag/PS composite microspheres. In the synthesis of PS dispersion, PVP was used as dispersant to stabilize the PS particles, it also acted as reducing agent in the reduction of [Ag(NH₃)₂]⁺ complex ions to silver, so no additional reducing agent was needed. The resulting composite microspheres were characterized by TEM, SEM, XPS, and XRD. The catalytic properties and surface‐enhance Raman scattering (SERS) was studied as well. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4547–4554, 2009     

一种新的两道工序柔性流水车间排序问题

本文针对F_2(p),h11.1|m_1=1,m_2=μ≥2|C_(max)这一问题给出了几种近似算法,并对每种近似算法进行了最坏情形分析,给出了最坏情形界.     

流量大小对混合流场特性等的影响

 在主、副气流各组份的流量比不变的情况下，改变输入氧碘化学激光器（COIL）光腔总气流流量，数值模拟给出了COIL拉伐尔喷管主、副气流混合状况和各物理量的分布等，通过对这些结果进行对比分析得出：输入COIL光腔总气流流量增加三倍，氧碘气流的混合状况稍稍变差，但Mach数和密度等的分布和变化规律基本不变。     

Determination of ferruginol in rat plasma via high‐performance liquid chromatography and its application in pharmacokinetics study

Ferruginol, a diterpene phenol, has recently received attention for its extensive pharmacological properties, including anti‐tumor, antibacterial, cardio‐protective and gastroprotective effects. In the present study, a high‐performance liquid chromatographic (HPLC) method was developed for determination of ferruginol in rat plasma and applied for the pharmacokinetics study. The HPLC assay was performed with a VP ODS‐C₁₈ column. The mobile phaseconsisted of methanol and 1% acetic acid solution (90:10, v/v). The flow rate was 1.0 mL/min, and the wavelength was set at 270 nm. This method was linear over the studied range of 0.1–10.0 µg/mL for ferruginol. The correlation coefficient was 0.9998. The intra‐day and inter‐day precisions were better than 4 and 5%, respectively. The extraction recovery and accuracy were greater than 97 and 96%, respectively. The detection limit was 30 ng/mL. The mean maximum concentration of ferruginol in rat plasma was 3.14 µg/mL at 40 min after oral administration at a dose of 20 mg/kg. Ferruginol was absorbed quickly p.o. with t_1/2ka = 14.86 min and had a high rate of elimination with t_1/2 = 41.73 min. The pharmacokinetic process of ferruginol in rat was well described with a one‐compartment model. Copyright © 2009 John Wiley & Sons, Ltd.     

Porosity, mechanical properties, residual stresses of supersonic plasma-sprayed Ni-based alloy coatings prepared at different powder feed rates

The aim of this paper was to investigate the effect of powder feed rate (PFR) on the microstructure and mechanical properties of the supersonic plasma-sprayed Ni-Cr-B-Si-C coatings. The microstructure, porosity and mechanical properties of the coatings and the residual stresses at the coating surfaces were experimentally determined. Results showed that the variations of porosity, elastic moduli and micro-hardness of the coatings followed Weibull distribution. From the statistical trend, the porosity of the coating increased with increasing PFR. However, the elastic modulus and the micro-hardness of the coating decreased and reached local minima and then increased with increasing PFR. Elastic modulus could be generally considered to be an increasing function of micro-hardness. The mean value of the elastic modulus of the coating calculated from Weibull plot was almost proportional to the square root of the mean value of the micro-hardness of the coating. Moreover, with increasing PFR, the residual stress at the coating surface, which was mainly governed by the elastic modulus of the coating, decreased to a local minimum and then increased.     

‘Best-case’ noise performance of feedback interferometers, potential for micromachine applications

We present a theoretical analysis of the noise performance of phase measuring feedback interferometers. We first analyse the operation of this kind of instrument and note that under certain circumstances bistability can occur. The bistable region should be avoided if possible when using feedback interferometry for high-accuracy measurement with low-input powers, as it can give rise to very high-noise levels. We then go on to investigate the effects of shot noise (on the interferometer output signal) and thermal noise (in the feedback loop), and relate these to the phase measurement accuracy of the interferometer. A ‘best-case’ calculation indicates that phase noise of about 0.005λ is possible at input powers in the nanowatt region. In practice, we expect that noise levels will be higher than predicted (particularly at high-input powers) due to the effects of vibration and air turbulence.