基于低功耗双边沿D触发器的任意进制异步计数器设计

从D触发器激励表入手，分别给出了采用单边沿D触发器和双边沿D触发器的2^n进制异步加法计数器、减法计数器的设计方法．在此基础上，采用逻辑函数修改技术，通过实例讨论了基于单边沿D触发器和双边沿D触发器的异步任意进制计数器的设计．该设计方法方便，快速，具有一定的实用意义．     

Prediction of aqueous solubility of drugs and pesticides with COSMO-RS

The COSMO-RS method, originally developed for the prediction of liquid-liquid and liquid-vapor equilibrium constants based on quantum chemical calculations, has been extended to solid compounds by addition of a heuristic expression for the Gibbs free energy of fusion. By this addition, COSMO-RS is now capable of a priori prediction of aqueous solubilities of a wide range of typical neutral drug and pesticide compounds. Only three parameters in the heuristic expression have been fitted on a data set of 150 drug-like compounds. On these data an rms deviation of 0.66 log-units was achieved. Later, the model was tested on a set of 107 pesticides, which have been critically selected based on two experimental data sources and by a crosscheck with an independent HQSAR model. On this data set an rms of 0.61 log-units was achieved, without any adjustments to the structurally extremely diverse pesticides. This result verifies the ability of this extended COSMO-RS to predict aqueous solubilities of drugs and pesticides of almost arbitrary structural classes. The new method is COSMO-RSol.     

Simultaneous Determination of Aluminum and Iron in High Salt Content Matrices by Adsorptive Stripping Voltammetry. Application to Dialysis Fluids

A new analytical procedure for the simultaneous determination of aluminum(III) and iron(II) in two kinds of dialysis fluids (peritoneal and hemodialysis fluids) by differential pulse adsorptive stripping voltammetry (DPAdSV) is described. The voltammetric measurements were performed using, as working electrode, a stationary mercury electrode, and a platinum electrode and a Ag|AgCl|KCl_(sat.) electrode as auxiliary and reference electrodes, respectively, employing acetate buffer solutions at different pH as supporting electrolyte. As complexing agents, Solochrome Violet RS, Palatine Chrome Black 6BN, Chromazurol S and Eriochrome Black T were employed. For both elements, the accuracy, expressed as relative recovery R%, was very satisfactory being in the range 94–105%, the precision as repeatability, expressed as relative standard deviation s_r%, was lower than 6%, while the limits of detection were of the order of a few units of μg/L. The analytical voltammetric procedure has been validated by comparison with spectroscopic (graphite furnace atomic absorption spectroscopy, GFAAS) measurements.     

Comparison of the fragility index of different eudragit polymers determined by activation enthalpies

The present study aimed to apply fragility index (m) of polymers in the determination of the optimal amount of plasticizer in polymer films. The fragility index of different Eudragit polymers (RS, RL, EPO) was assessed by differential scanning calorimerty (DSC), applying the Arrhenius connection (logq–1/T _g). The fragility of Eudragit EPO films proved to be the highest, while in the case of RS and RL, the increase of the alkyl-chain length caused the increase of fragility. Studying the effect of plasticizer (triethyl citrate, TEC) on the m value of Eudragit RL and RS films, a near linear reduction of the fragility index could be observed between 5–30% TEC concentration, but above 30%, this value leveled out to constant.     

High‐performance liquid chromatographic enantioseparation of (RS)‐bupropion using isothiocyanate‐based chiral derivatizing reagents

A high‐performance liquid chromatographic (HPLC) method for enantioseparation of bupropion was developed using two isothiocyanate‐based chiral derivatizing reagents, (S)‐1‐(1‐naphthyl) ethyl isothiocyanate, (S)‐NEIT, and (R)‐α‐methyl benzyl isothiocyanate, (R)‐MBIT. The diastereomers synthesized with (S)‐NEIT were enantioseparated by reversed‐phase HPLC using gradient elution with mobile phase containing water and acetonitrile, whereas diastereomers synthesized with (R)‐MBIT were enantioseparated using triethyl amine phosphate buffer and methanol. Derivatization conditions were optimized and the method was validated for accuracy, precision and limit of detection. The limit of detection was found to be 0.040–0.043 µg/mL for each of the diastereomers prepared with (S)‐NEIT. Copyright © 2013 John Wiley & Sons, Ltd.     

Highly Sensitive AdSV Method for Fe(III) Determination in Presence of Solochrome Violet RS on Renewable Amalgam Film Electrode

The new DP AdSV method for high sensitive Fe(III) determination in the presence of Solochrome Violet RS was developed. The use of an innovative renewable amalgam film electrode Hg(Ag)FE allowed to obtain high sensitivity and significantly minimize the mercury consumption. The best results were obtained for surface area of Hg(Ag)FE equal to 11.8 mm². Instrumental parameters were optimized. The optimal results were obtained using differential pulse technique for the following values: sampling and waiting time ts=tw=10 ms, step potential Es=5 mV, pulse amplitude ΔE=50 mV. Measurements were conducted in 0.05 M acetate buffer (pH 5.6), the concentration of SVRS was equal to 5 μM. Deposition step was carried out at the potential ?400 mV for 20 s. Calculated detection limit for 40 s preconcentration time was equal to 1.4 nM (78 ng L^?1). The influence of the common in environment, organic and inorganic interferences was studied. The developed method for Fe(III) determination was successfully applied and validated by investigation of certified reference material SPS‐SW2 Batch 118 and recovery of Fe(III) from various spiked samples as snow, tap water and bottom sediments. The repeatability (for 50 nM of Fe(III)) of the developed method expressed as CV was equal 3.1 % (n=5).     

Application of Non-Destructive X-Ray Fluorescence Spectrometry to the Analysis of Suspended Matter in Sea Water

Abstract

In the framework of remote sensing studies concerning coastal transport of pollution in the Northern Adriatic Sea, a method has been developed for the quantitative determination of sulphur, iron, titanium, calcium, phosphorus, silicon, aluminium, magnesium in suspended matter of sea water.

The suspended material was collected by filtering on millipore membrane filters with pore width of 0.45 μ and directly analysed by X-ray spectroscopy. For calibration dried solution and particulate standard samples were used. Limits of sensitivity and precision of the method are reported.

Correlations between the concentration of these elements and the total suspended matter/chlorophyll are discussed.

The aim is to study the geochemical composition of particulate matter and its variations within the geographical site of the sea basin and the seasonal conditions. The approach is to consider aluminium and the other elements normalized on Al. On the basis of a matrix correlation analyses of some sets of data chosen in the restricted area for investigation, some hypothesis on superficial distribution of clay, carbonate, iron hydrous oxides and other mineral detrites, are taken into account. The results confirm the complex situation existing in the offshore area of the Venice lagoon from a geochemical point of view.

The suspended matter seem to be argillaceous in the Southern part of the investigated area and semi-argillaceous with hydrous oxides and carbonates in the Northern part which is influenced by the Piave river.     

集值映射的 RS集逼近

本文研究了取值为 Banach空间中子集的上半连续的集值映射的 RS集逼近问题 ,给出了集值映 射用 RS集逼近的特征和唯一性结果 ,从而推广了他人的结果 .     

Effect of the spectral profile of a deriving field on the bistability of a dissipative medium

 Through the differential equation describing the behavior of the nonlinear polarization of a medium with respect to an incident field, the Maxwell field equations and the boundary conditions of the field inside a resonator, the relationship between the output and the incident fields is obtained, describing a bistability phenomena. The effect of the spectral profile of the incident field and its spectral halfwidth on the bistability phenomena is studied.