A Novel Dihydroflavone from the Roots of Uvaria Macrophylla

A new dihydroflavone (1), named macrophyllol A, was isolated from the roots of Uvaria macrophylla. Its structure was elucidated on the basis of spectroscopic evidence.     

大孔吸附树脂合成及从甜叶菊中提取分离甜菊甙的研究

本文合成了一系列用于从甜叶菊提取液中吸附分离甜菊甙的大孔吸附树脂，测定了它们的孔结构参数及吸附量，并比较了吸附量较高的五种树脂的循环使用性能及解吸性能。实验结果表明，Ｍ－３５树脂吸附量大，解吸率高，用树脂法工艺制备的甜菊甙产品纯度高，质量好。     

多嵌段聚氨酯大孔共聚物的制备

多嵌段聚酯大孔共聚物经缩聚和加聚反应分步聚合得到，并利用ＦＴＩＲ，ＤＳＣ，ＳＥＭ和ＢＥＴ等对其结构、形态结构和孔结构进行了比较详细的研究。结果表明，该聚合物为微相分离且可能存在三种微区结构的多嵌段共聚物，其干态下的比表面积有１０－２５０ｍ＾２／ｇ之间，平均孔径在１００－３５０Ａ左右，在聚合温度下，接近于聚氨酯θ条件的溶剂为最佳致孔剂。     

THERMODYNAMIC STUDY OF ADSORPTION OF PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTION BY A WATER-COMPATIBLE HYPERCROSSLINKED POLYMERIC ADSORBENT

Equilibrium data for the adsorption of phenolic compounds, i.e., phenol, p-cresol, p-chlorophenol and p-nitrophenol from aqueous solutions by a water-compatible hypercrosslinked polymeric adsorbent (NJ-8) within temperature range of 283-323 K were obtained and correlated with a Freundlich-type of isotherm equation, so that equilibrium constants KF and n were obtained. The capacities of equilibrium adsorption for all the four phenolic compounds on the NJ-8 from aqueous solutions are around 2 times as high as those of Amberlite XAD-4, which may be attributed to the unusual micropore structure and the partial polarity on the network. The values of the enthalpy (always negative) are indicative of an exothermic process, which manifests the adsorption of all the four phenolic compounds on the two polymeric adsorbents to be a process of physical adsorption. The negative values of free energy change show that the solute is more concentrated on the adsorbent than in the bulk solution. The absolute free energy values of adsorption for NJ-8 are always higher than those for Amberlite XAD-4, which indicates that phenolic compounds are preferentially adsorbed on NJ-8. The negative values of the adsorption entropy are consistent with the restricted mobilities of adsorbed molecules of phenolic compounds as compared with the molecules in solution. The adsorption entropy values of phenolic compounds for NJ-8 are lower than those for Amberlite XAD-4, which means the micropores of NJ-8 require more orderly arranged adsorbate.     

含呋喃环Schiff碱型大环化合物的合成及其与Ba^2+,Sr^2+配合行为

利用Mn^2+，Ba^2+及Sr^2+作为模板离子，合成了一类新型的含呋喃环系 Schiff碱型大环化合物，如L^1和配合物L^2Ba(ClO4)2，L^3Ba(ClO4)2和L^4Ba (ClO4)2.L^2-L^4的Ba^2+配合物经与NaSO4水溶液反应解络，得到自由配体L^2， L^3和L^4，配体L^2和L^3分别与Sr^2+作用，得到配合物L^2Sr(ClO4)2和L^3Sr (ClO4)2。上述大环配体和各种配合物均经元素分析，IR，^1H NMR，MS等证实了它 们的结构和组成。     

STUDIES ON MACROPOROUS POLYMER SUPPORTED ASYMMETRIC HYDROGENATION CATALYSTS

The supported Rh-DIOP complexes were prepared through functionalization of several macroporous polystyrene resins nd were evaluated by the hydrogenation of acetamidocinnamic acid in EtOH.The pore effect of the matrixes was discussed.     

后交联型St-DVB大孔吸附树脂对低级醇类的吸附性能研究

分别在静态和动态条件下研究了Friedel—Crafs后交联型聚苯乙烯-二乙烯基苯(St-DVB)大孔吸附树脂对水溶液中多种低级一元醇的吸附性能，测定静态吸附等温线和动态吸附曲线，并分别按照Langmuir和Freundlich模型进行拟合．结果显示，树脂对水中低浓度低级一元醇的吸附过程属于放热的物理吸附过程，树脂吸附能力随着一元醇碳原子数的增加，即分子内疏水基团质量的增加而增加；树脂对直链醇的吸附能力稍强于同分异构的支链醇．     

STUDIES ON THE SORPTION OF MACROPOROUS PHOSPHONIC ACID RESIN FOR LANTHANUM

The influences of Medium pH,sorption temperature,sorption time,etc.on the sorption capacity of macroporous phosphonic acid resin for La^3+ were determined.The sorption rate constant was k298=7.64×10^-5 s^-1. The complex ratio of phosphonic groups of the resin to La^3+ was 3:1.The basic sorption parameters were determined. The sorption mechanism of macroporous phosphonic acid resin for La^3+ was examined by chemical analysis and IR-spectrometry.     

柠檬酸在D354树脂上的离子交换研究

研究了大孔型弱碱性阴离子交换树脂Ｄ３５４分离水中柠檬酸的相平衡和动力学。Ｌａｎｇｍｕｉｒ方程能够良好地关联等温线。建立了离子交换过程的孔扩散模型，并以正交配置法与Ｇｅａｒ法结合进行数据拟合。结果表明，液膜阻力对交换过程具有重大影响，简单线性推动力模型能够很好地描述液膜传质过程。     

Construction of Spatiotemporal-Coupling Optimal Low-Dimensional Dynamical Systems for Compressible Navier-Stokes Equations; [可压缩 Navier-Stokes 方程的时空耦合优化低维动力系统建模方法]北大核心CSCD

For the low-dimensional dynamical system model to study dynamics properties of Navier-Stokes equations, it is very important that the attraction domain of the low-dimensional model is the same as that of Navier-Stokes equations. However, to date, there is no universal approach to ensure this purpose for general problems. Herein, it is found that any low-dimensional model based on spatial bases, such as proper orthogonal decomposition bases, optimal spatial bases, and other classical spatial bases, is not predictable, i.e., the error increases with the time evolution of the flow field. With the theoretical framework for building optimal dynamical systems and the new concept of spatiotemporal-coupling spectrum expansion, the low-dimensional model for compressible Navier-Stokes equations was constructed to approximate the numerical solution to large-eddy simulation equations, and the numerical results and novel time evolution of spatiotemporal-coupling bases were given. The entire field error is typically below 10−2%, and the average error at each grid point is below 10−8%. The spatiotemporal-coupling optimal low-dimensional dynamical systems can ensure that the attraction domain of the low-dimensional model is the same as that of Navier-Stokes equations. Therefore, characteristic dynamics properties of spatiotemporal-coupling optimal low-dimensional dynamical systems are the same as those of real flow. © 2022 Editorial Office of Applied Mathematics and Mechanics. All rights reserved.