利用电子俘获材料实现光学IPA神经网络模型

报道用自行研制的ＣａＳ（Ｅｕ，Ｓｍ）电子俘获材料表示互联机重矩阵以实现光学ＩＰＡ神经网络模型，由于ＣａＳ（Ｅｕ，Ｓｍ）的红外激励发光强度与俘获的电子密度及红外读出光强度之积成线性关系，故可用来表示互联权重矩阵以实现光学神经网络，这种互联权重矩阵具有很宽的数值范围，并可以用光学的办法进行快速擦除，重写。     

Polyamide-imide/polyetherimide dual-layer hollow fiber membranes for pervaporation dehydration of C1–C4 alcohols

To circumvent the common swelling and deteriorated performance of integral asymmetric hollow fiber membranes for pervaporation dehydration, we have developed novel polyamide-imide (PAI)/polyetherimide (PEI) hollow fiber membranes with synergized performance with the aid of dual-layer spinning technology. Dehydration of C1–C4 alcohols has been conducted and the orders of their fluxes and permeances have been analyzed. The hollow fibers spun at 2 cm air gap and annealed at 75 °C exhibit the highest pervaporation performance: separation factors for t-butanol/water and iso-butanol/water binary systems are greater than 50,000 with flux more than 700 g/m² h. A comparison with literature data shows that the newly developed membranes outperform most other polymeric membranes for the dehydration of IPA and butanols. The dual-layer hollow fiber membranes also exhibit good long-term stability up to 200 h. The superior performance can be attributed to (1) the balanced properties of PAI as the selective layer for dehydration pervaporation; (2) the low water uptake and less swelling characteristic of the PEI supporting layer; and (3) the desirable membrane morphology consisting of a fully porous inner layer, a porous interface, and an ultrathin dense-selective outer skin.     

Surface modification by deposition of IPA plasma and gellan gum/chitosan hybrid hydrogel onto thermoplastic polyurethane for controlled release of N‐acetylcysteine

A thin film system composed of gellan gum and chitosan was fabricated through a combination of polyelectrolyte blend and hybrid hydrogel gelation for controlled release of drug. In this study, precursor isopropyl alcohol (IPA) was used to plasma deposit on the surface of thermoplastic polyurethane (TPU) to form a hydrophilic film. The features of the thin film were evaluated using water contact angle (WCA) measurement, scanning electron microscopy (SEM), Fourier transform infra‐red (FTIR), UV/Vis spectroscopy, and studies of controlled release of drugs. The hybrid hydrogel, pH‐sensitive, was tested at pH values of 1.2 and 7.4 of buffer solution and at a temperature of 37°C to observe its swelling ratio and drug delivery properties with N‐acetylcysteine as a drug material for controlled release. Furthermore, at pH 7.4, the hybrid hydrogel has an outstanding release ratio of up to about 90% absorption amounts of N‐acetylcysteine after 8 hr. The mechanism of drug release from thin film devices (n = 0.684) is anomalous (non‐Fickian) transport, the value of n lies between 0.43 and 0.85.     

IPA Derivatives for Make-to-Stock Production-Inventory Systems with Backorders

A single-stage Make-to-Stock (MTS) production-inventory system consists of a production facility coupled to an inventory facility, and is subject to a policy that aims to maintain a prescribed inventory level (called base stock) by modulating production capacity. This paper considers a class of single-stage, single-product MTS systems with backorders, driven by random demand and production capacity, and subject to a continuous-review base-stock policy. A model from this class is formulated as a stochastic fluid model (SFM), where all flows are described by stochastic rate processes with piecewise constant sample paths, subject to very mild regularity assumptions that merely preclude accumulation points of jumps with probability 1. Other than that, the MTS model in SFM setting is nonparametric in that it assumes no specific form for the underlying probability law, and as such is quite general. The paper proceeds to derive formulas for the (stochastic) IPA (Infinitesimal Perturbation Analysis) derivatives of the sample-path time averages of the inventory level and backorders level with respect to the base-stock level and a parameter of the production rate. These formulas are comprehensive in that they are exhibited for any initial condition of the system, and include right and left derivatives (when they do not coincide). The derivatives derived are then shown to be unbiased and their formulas are seen to be amenable to fast computation. The generality of the model and comprehensiveness of the IPA derivative formulas hold out the promise of gradient-based applications. More specifically, since the base-stock level and production rate are the key control parameters of MTS systems, the results provide the theoretical underpinnings for optimizing the design of MTS systems and for devising prospective on-line adaptive control algorithms that employ IPA derivatives. The paper concludes with a discussion of those issues.     

Sensitivity analysis via simulation in the presence of discontinuities

In this paper we address the problem of estimating the mean derivative when the entity containing the parameter has jumps. The methods considered are finite differences, infinitesimal perturbation analysis and the likelihood ratio score function. We calculate the difference between the differentiated mean and the mean derivative. In case of finite differences, we compute the stepsize in the simulation that asymptotically minimizes the mean square error. We also show that the two latter methods, infinitesimal perturbation analysis and likelihood ratio score function, are mathematically equivalent.     

吲哚羧酸与铽离子的作用及其构象研究

本文使用铽（Ⅲ）为荧光探针，探讨了吲哚－３－乙酸（ＩＡＡ）、吲哚－３－丙酸（ＩＰＡ）、吲哚－３－丁酸（ＩＢＡ）与铽（Ⅲ）的作用。基于Ｆｏｒｓｔｅｒ偶极－偶极无辐射能量传递机理，推算了结合铽（Ⅲ）与吲哚环的ＩＡＡ、ＩＰＡ、ＩＢＰ的距离，它们分别是７．９７Ａ，１０．２９Ａ，１２．５６Ａ。     

IPA型菲涅尔全息联想存贮器

本文提出了一种用菲涅尔全息片实现的IPA(Interpattern Association)型联想存贮器。其对不独立的存贮模式有较强的分辨能力,采用菲涅尔全息片,可以实现大神经元数目的光学联想存储,具有较大的存储能力。     

离子色谱法同时测定脱硫液中的四种醇胺

建立了同时分离测定异丙醇胺(IPA)、三异丙醇胺(TIPA)、N-甲基二乙醇胺(MDEA)、N,N-二甲基二乙醇胺(DMAE)和6种阳离子的离子色谱法。色谱柱为TSKgelSuperIC-CR阳离子交换柱,流动相为冠醚(2.0mmol/L)、甲基磺酸(2.2mmol/L)、L-组氨酸(0.5mmol/L)混合溶液,流速为0.5mL/min,抑制电导检测。DMAE、MDEA、TIPA、IPA的检出限分别为0.48、36.9、47.04和1.39μg/L;样品中DMAE、MDEA、TIPA、IPA平均回收率为103.15%,95.48%,97.64%,92.41%。方法具有简单、快速、灵敏、抗干扰等优点,用于测定脱硫液中的DMAE、MDEA、TIPA和IPA,结果令人满意。     

仅用激发神经元的IPA神经网络模型及其光学实现

仅用激发神经元的IPA(Interpattern Association)型神经网络模型与既有激发又有抑制的IPA模型具有相似的性能。仅用激发神经元后,不需要光强的相减,这样可以较简单地实现全光神经网络系统,对相似的存储模式有较强的分辨力。此文提出了一套二维(8×8)光学神经网络实验系统,用透镜阵列实现互连,并给出了理论描述和光学实验结果。     

Characterization by NMR of reactants and products of hydrofluoroether isomers,CF3(CF2)3OCH3 and (CF3)2C(F)CF2OCH3, reacting with isopropyl alcohol

The 3M Company product Novec? 71IPA DL, a mixture of methoxyperfluorobutane, methoxyperfluoroisobutane and 4.5 wt.% isopropyl alcohol, has been found to be very stable at ambient temperature, producing fluoride at the rate of ~1 ppm/year. Our earlier kinetic and theoretical studies have identified the reaction mechanism. This paper identifies the ¹H and ¹⁹F NMR chemical shifts, multiplicities, and coupling constants of reactants and the major products that result from aging the mixture in sealed Pyrex NMR tubes for periods up to 1.8 years at temperatures from 26 °C to 102 °C. Chemical shifts and coupling constants of fluorine and hydrogen atoms on the hydrofluoroethers and isopropyl alcohol are traced through the reactions to their values in the products – esters, isopropylmethyl ether, and HF. These spectral positions, multiplicities, and coupling constants are presented in table format and as figures to clarify the transformations observed as the samples age. Copyright © 2013 John Wiley & Sons, Ltd.