多相泵设计方法初探

１引言由于多相泵输送的是气液两相混合介质,而且其中气或液的含量往往高于常规泵或压缩机的工作范围,所以多相泵应兼备压缩机和泵的性能,这使多相泵的设计成为一个难点。到目前为止,国外已开发研制出的多相泵主要有容积式和叶片式［１］,业已进入现场试验和工业化应用阶段,但离形成完整的设计方法还有一定距离,国内这方面的工作则刚刚起步。所以目前对于多相泵尚没有成熟的设计方法,还不能象清水泵那样,按给定的流量、扬程、转速等参数进行可靠的设计。在多相泵的设计中,人们关心的主要问题是：泵型选择、总体设计方案的确定、效…     

A mini-review of polymeric porous membranes with vertically penetrative pores

Membrane separation technology plays a pivotal role in modern industry and scientific research. The key to developing and improving membrane separation processes lies in designing and fabricating customized porous membranes with specific physical parameters, including pore diameter, porosity, pore size distribution, pore length (membrane thickness), pore geometry, and pore connectivity. Polymeric porous membranes with vertically-penetrative-pores (PPMVs) represent a distinct category among the available membranes due to their unique characteristics such as short transport path, small trans-membrane resistance, and simple pore geometry, as compared to other porous membranes with sponge-like channels. In practical applications, PPMVs offer several advantages, including achieving higher flux rates, facilitating easier unidirectional transport, and enabling harmless biological extraction. Moreover, PPMVs can serve as ideal model systems for theoretical investigations on the fundamental mechanisms of separation and transport in academic research. With substantial advancements in fabrication technologies and application fields of PPMVs in recent years, it warrants a comprehensive perspective. In this mini-review, we provide an overview of widely used fabrication methods for PPMVs, discuss their primary applications, and address the existing challenges and opportunities.     

双倒易边界元拓展于模拟生物组织中热波传播问题

1前言双倒易边界元是一个新发展的纯边界积分数值方法＊，乞今在热波传播问题的应用尚未见到报导。对热波在工程材料中传播的反射和衰减特性已作过一些研究，但它们均局限在快速温度变化及极低温情形．生物组织热波传播问题的研究则尚未见到报导。我们曾用有限差分法考察过一维情况下热波在不同时刻下的演化情况，算例中波形存在锯齿这是由于有限差分误差所致．热波问题的数值模拟，需要对热波及其分解、叠加和反射能进行准确定位与精确捕获。在已发表的有限差分泡括采用了TVD高精度算法）数值解中报道了热波前沿存在严重的数值脉动。边界…     

光折变聚合物材料研究进展

综述近年来光折变聚合物的材料的研究现状，着重介绍光折变聚合物材料的化学结构，组成及光折变性能。简单分析当前研究工作所面临的问题。     

聚合物支载的甘氨酸与Cu^2＋离子的络合性能

本文用N-（3-聚苯乙烯磺酰基-2-羟基丙基）甘氨酸为模型，研究了聚合物支载的氨基酸与Cu2 离子的络合作用性能。树脂与铜离子络合的介质最佳pH值在2～3之间。按照方程：－1n（1－F）=KTt处理求得吸附速率下数K288＝2．47X10－4sec－1。根据Boyd液膜扩散理论，这一吸附过程主要受液膜扩散控制。而且这个反应过程是一种Freundlish吸附过程。G=－30．91KJ／mole和S=129．90J／moleK表明，吸附反应是自发进行的。用斜率法和容量法求得树脂支载的氨基酸基因与铜离子之间的配位比为2:1。     

聚合物超强酸催化剂及其应用

本文综述了各种有机聚合物超强酸体系的分类、合成、结构、以及它们在石油化工和有机合成中的催化作用。     

应用漫反射红外光谱技术优化2-聚苯乙烯磺酰胺基乙醇树脂的合成

本文采用漫反射红外光谱法优化一种新的固相合成载体2－江西 乙烯磺酰胺基乙醇树脂的合成。聚苯乙烯磺酰氯树脂在有或没有溶剂和／或催化剂存在下与乙醇铵反应得到2－聚苯乙烯磺酰胺基乙醇树脂。漫反射红外光谱跟踪整个反应过程。结果表明，漫反射红外光谱技术是优化制备新的功能基化聚合物条件的有力工具。2－聚苯乙烯磺酰胺基乙醇树脂的优化制备条件是：聚苯乙烯磺酰氯，乙醇胺在60℃反应30min。     

Synthesis and characterization of near-infrared absorbing and fluorescent liquid-crystal chromophores

This work demonstrates that the donor-acceptor-donor charge-transfer chromophores can be tailor-made to be near-infrared absorbing and fluorescent, as well as being liquid crystals. The chromophore containing an extremely strong acceptor of benzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) can form a columnar mesophase that absorbs at 890 nm and emits at 1160 nm in the solid state. These chromophores are readily soluble in common organic solvents and can form thin films by casting or spin coating, making them suitable for further device applications.     

General dispersion and dissipation relations in a one-dimensional viscoelastic lattice

We derive the general dispersion and dissipation relations for a one-dimensional viscoelastic lattice, demonstrate the relevance of these relations to viscoelastic fracture and phase transition, and show a procedure to determine the suitable mesh size in numerical simulation of stress waves propagating in viscoelastic continuum.     

Isolation and structure elucidation of two new compounds from artemisia Ordosica Krasch

Abstract

Two new compounds, namely arteordoyn A (1) and arteordoyn B (2), together with four known compounds, were isolated from the petroleum ether extract of Artemisia ordosica Krasch. The structures elucidation of 1 and 2 were carried out by 1D-NMR (¹H and ¹³C NMR), 2D-NMR (COSY, HSQC, HMBC and NOESY) and HR-ESI-MS spectral analysis.