苯并噻唑类离子液体在乳酸酯中的溶解度测定

为促进离子液体的应用,在常压下由平衡法测定了3种新型苯并噻唑类离子液体在乳酸甲酯、乳酸乙酯中的溶解度,温度范围为253.15～333.15 K,用λh方程对溶解度数据进行了关联,关联效果理想。该类离子液体表现出的"温敏性"对其在反应结束后的回收及循环使用具有重要意义。     

无机类化合物蒸气压数学模型的研究

通过对无机类化合物蒸气压估算方法的研究,利用手册或软件中的数据库,来查找无机类化合物的蒸气压数据,运用一定的数学分析方法和Ofigin软件对已有的蒸气压数据进行回归,给出最大相对误差、最小相对误差,提高了计算数据的准确度,为生产、设计提供了依据。     

黄藤素溶解度的测定与关联

在黄藤素的提取分离过程中,其在不同溶剂中的溶解度数据对其结晶纯化有重要的指导意义。本文以UV法测定了298.12-313．12K时黄藤素在纯水、甲醇、乙醇、三氯甲烷等不同溶剂中的溶解度数据,为黄藤素的结晶纯化提供了基础的热力学数据。试验结果表明,黄藤素在四种溶剂中的溶解度均随温度的升高而增加。对试验结果采用Apelblat方程进行拟合,其溶解度关联值与试验值比较稳合。     

“华中”数控系统椭圆宏程序车削指令的编程举例

以华中世纪星HNC-21T数控车削系统为例,利用椭圆标准方程与数控机床坐标系之间的转化,对数控车床各类椭圆（不同象限的凹凸椭圆）进行分析和编程,通过实例研究宏程序编程的关键技术,并作为模板推广使用。     

Production of Ultrapure Bentonite Clays through Centrifugation Techniques

In this study, the production of ultrapure Na-bentonite by centrifuge based techniques for organo and nano composite bentonite industry was investigated. Various parameters including centrifuging time, solids content, and g force were studied to determine the set points (cut size) for theoretical CEC (cation exchange capacity) and recovery limits. The experimental results were modeled using Response Surface Method (RSM) with high responses (regression > 85% and correlation coefficients > 0.85). it is shown that the commercial centrifugation equipment operating with residence time of 10–15 seconds and g values lower than 300 g such as Multi Gravity separator (MGS), Hydrocyclones and Falcon/Knelson concentrators are not suitable for obtaining pure quality Na-bentonite, since the set point size (5-8 µm) is higher than 2 µm which is defined for bentonite of high smectite contents. The RSM models demonstrate that only the kind of separators such as decanter centrifuges with operational g forces higher than 600 may exhibit the closest set point to 2 µm and thus enable the achievement of an ultra pure quality bentonite product. These assumptions obtained from the developed model were confirmed by running tests on Falcon and Mozley hydrocyclone separators.     

Quantum transport simulations of graphene nanoribbon devices using Dirac equation calibrated with tight-binding π-bond model

We present an efficient approach to study the carrier transport in graphene nanoribbon (GNR) devices using the non-equilibrium Green''s function approach (NEGF) based on the Dirac equation calibrated to the tight-binding π-bond model for graphene. The approach has the advantage of the computational efficiency of the Dirac equation and still captures sufficient quantitative details of the bandstructure from the tight-binding π-bond model for graphene. We demonstrate how the exact self-energies due to the leads can be calculated in the NEGF-Dirac model. We apply our approach to GNR systems of different widths subjecting to different potential profiles to characterize their device physics. Specifically, the validity and accuracy of our approach will be demonstrated by benchmarking the density of states and transmissions characteristics with that of the more expensive transport calculations for the tight-binding π-bond model.     

离子液体的溶液热力学模型研究进展

离子液体是近年来发展起来的一种绿色介质,在化工反应和分离过程中具有广泛的应用前景。离子液体的溶液热力学性质和相平衡数据是其相关工艺过程设计的基础。本文从如下几个方面综述了离子液体溶液热力学模型的研究进展,即溶液热力学研究方法、溶液热力学模型的构建、离子液体的结构和分子间作用力、离子液体的溶液热力学模型及其在相平衡计算中的应用。重点分析了适用于离子液体溶液热力学性质计算的状态方程模型和过量Gibbs自由能模型或活度系数模型,离子液体的电解质和非电解质溶液模型,以及这些模型对ILs结构、氢键和静电作用的处理方法。分析了这些模型的优缺点,并对今后离子液体的溶液热力学研究提出了建议。     

复杂炼油塔模拟的改进联立方程内外层算法

在内外层算法的基础上,采用联立方程思想将主塔、侧线汽提塔视为一个整体进行建模,并针对复杂炼油塔的特点对算法提出了改进。首先,由于传统内外层法简化的K值模型对组成的变化不敏感,在处理带有石油的体系时,容易出现迭代次数较多,甚至部分塔板温度更新异常的问题,因此采用了汽相分数加和式推导了简化的K值模型加权因子。其次,借鉴流量加和法思想,规定侧线汽提塔的塔底产品流量作为设计变量,增强了算法收敛的稳定性。为验证改进后算法的有效性,采用不同的算法对实际的常压塔进行了模拟,结果显示改进后的算法适合应用于复杂炼油塔的模拟计算。     

An efficient nonlinear polynomial color characterization method based on interrelations of color spaces

A well-known color characterization method is to take an image of a color chart and then to find the mapping matrix from the digital RGBs to the corresponding known CIEXYZs. However, the prediction errors are generally large in CIELAB color space because of the nonlinear transformation from CIEXYZs to CIELABs. In this article, we propose an efficient and simple nonlinear method for the color characterization of input devices. The approach for deriving a colorimetric mapping between digital RGB signals and CIELAB tristimulus values uses the polynomial modeling by considering the interrelations among the standard CIE color spaces. Furthermore, to improve the accuracy of solution, we take the polynomial root terms extension. Our algorithm is simple to implement because only a least-squares mapping should be solved. Various computational results are given to demonstrate the efficiency and capability of the proposed method.     

The Marginal Density of a TMA(1) Process

This note reconsiders the marginal density of a threshold moving average process and proposes a simple yet effective numerical algorithm to implement that by solving an associated integral equation. This algorithm can also be applied to calculate stationary probability density or distribution functions of a few other types of nonlinear stationary stochastic processes numerically.