环状分子交联剂的合成及其改性硅橡胶膜的富氧性能

通过控制2,4,6,8-四甲基环四硅氧烷(D4H)和乙烯基三甲氧基硅烷(VTMO)的摩尔比合成了环状分子上含有硅氢原子和三甲氧基硅基的交联剂,并用IR进行了表征.以乙烯基摩尔分数为10%的硅橡胶和上述交联剂为基质材料,以氯铂酸为催化剂,经溶液浇铸和通过双重交联反应──乙烯基与硅氢的加成反应和三甲氧基硅基的水解、缩合反应制备了改性硅橡胶气体分离膜.气体渗透的测试结果表明,该膜具有良好的富氧性能,例如,在20℃和0.05 MPa压差下,PO2为595 Barrer,αO2/N2高达2.89.改性硅橡胶膜的成膜过程和交联反应可在室温下同时进行,与其它改性硅橡胶膜相比,不仅改性方法简单,且分离性能明显提高.     

乳液涂敷制备硅橡胶富氧膜

实验制备了聚二甲基硅氧烷/聚砜（PDMS/PS）富氧膜,并考察其富氧性能,分别制备了溶剂型羟基硅橡胶富氧膜和乳液型羟基硅橡胶富氧膜,评价其渗透速率Q和分离系数α（O₂/N₂）,得出了二者在性能上的差异,发现溶剂型富氧膜渗透速率Q（O₂）是乳液型富氧膜Q（O₂）的3～4倍,而乳液型富氧膜的分离系数α（O₂/N₂）比溶剂型富氧膜略好,并且以水代替有机溶剂,采用硅橡胶水乳液作为涂敷材料进行乳液涂敷,制备的乳液型富氧膜相对于传统的溶剂型富氧膜,具有环保、安全和经济等特点.该方法制备的富氧膜同时也具有较好的富氧效果,其氧气渗透速率Q（O₂）在113 GPU左右,分离系数α（O₂/N₂）能达到2.0.     

有于氧氮分离促进输送膜的研究

报道对氧的促进输送膜的研制和膜的性能测定工作。以Ｃｏ（３ＦＳａｌｅｎ）为氧载体，用简便的方法制备了聚砜－硅橡胶－氧载体复合膜；研究了制备方法和制备条件对膜渗透和分离性能的影响。实验结果表明，促进输送膜能有效地在提高氧氮分离系数α０／Ｎ的同时，也提高膜对氧的透气速率Ｐ０，采用混合固体氧载体的制膜方法也有独特的优点。     

用于氧氮分离促进输送膜的研究

报道对氧的促进输送膜的研制和膜的性能测定工作以Ｃｏ（３ＦＳａｌｅｎ）为氧载体，用简便的方法制备了聚砜－硅橡胶－氧载体复合膜；研究了制备方法和制备条件对膜渗透和分离性能的影响实验结果表明，促进输送膜能有效地在提高氧氮分离系数αＯ／Ｎ的同时，也提高了膜对氧的透气速率ＰＯ．采用混合固体氧载体的制膜方法也有独特的优点．     

硅橡胶富氧膜材料研究进展

介绍了气体膜分离原理和常见的高分子富氧膜材料的透气分离性能,针对硅橡胶富氧膜材料近些年的改性研究进行了综述和分析,指出在高乙烯基含量硅橡胶中加入起到促进传递作用的金属钴络合物、氟元素以及小分子液晶等,能显著改善富氧膜的选择透过性。而利用超临界CO2对硅橡胶富氧膜进行溶胀改性以及在富氧膜材料中添加铁氧体制备所谓的富氧"磁化膜",有望成为未来富氧膜开发研究的一个新方向。     

PVDF-PANI共混膜气体分离性能的研究

采用PANI与PVDF共混制膜，并对共混膜和PVDF膜的气体分离性能进行对比研究。实验发现：与PVDF膜相比，PANI的加入，使得共混膜的气体渗透速率J和理想分离因数α发生了明显的变化，有利于αO2／N2，αO2／CO2的提高；PANI在共混膜中的百分含量直接影响到气体渗透速率J和理想分离因数α变化的大小。     

聚醚酰亚胺中空纤维气体分离膜及结构

以聚醚酰亚胺为膜材料，N—甲基吡咯烷酮为溶剂，采用干／温法纺丝技术制备聚醚酰亚胺中空纤维气体分离膜、研究了不同芯液组成和中空纤维热处理对O2/N2、H2/N2和He／N2膜性能的影响、当芯液组成为m(NMP)：m(H2O)=19：1时，涂层的聚醚酰亚胺中空纤维膜气体分离性能如下：αO2/N2=4．22，αHe/N2=83.9，αH2/N2=165，JO2=3．25GPU，JHe=64．6GPU和JH2=127GPU；该膜经过150℃热处理1h后，其气体分离性能如下：αO2/N2=7．57，αHe/N2=304，αH2/N2=512，JO2=0．833GPU，JHe=33.4GPU和JH2=56．3GPU。用扫描电镜对膜结构、中空纤维膜制备中的相转化过程进行了研究，讨论了聚醚酰亚胺中空纤维共混膜的机械性能。     

顺丁橡胶与液晶共混复合膜的CO2渗透性能

以顺丁橡胶（ＰＢ）和具有双重液晶相的液晶化合物双－４－（４’－乙氧基苯甲酰氧基）苯甲酸－缩乙二醇酯（ＤＥＢＥＢ）制成高分子／液晶复合膜并研究了其ＣＯ２透过性能。液晶含量为１０％（质量）复合膜在室温下具有比ＰＢ膜大５倍以上的ＣＯ２透过系数（Ｐｃｏ２）及好的与Ｎ２、Ｏ２分离系数（αｃｏ２／Ｎ２、αｃｏ２／ｏ２）：Ｐｃｏ２＝４３２ｂａｒｒｅｒ,αｃｏ２／Ｎ２＝２５．４,αｃｏ２／ｏ２＝７．９;且透气系数     

含氢硅油交联RTV硅橡胶的形态与性能

研究了两种不同氢基含量的含氢硅油对室温硫化硅橡胶力学性能、电学性能以及硫化时间的影响。结果表明,低含氢量的含氢硅油比高含氢量硅油显示出了更好的交联效果,且当其添加量为基础胶料质量的4%时,硫化硅橡胶显示出最好的综合性能。     

含氢硅油交联PTV硅橡胶的形态与性能

研究了两种不同氢基含量的含氢硅油对室温硫化硅橡胶力学性能、电学性能以及硫化时间的影响.结果表明,低含氢量的含氢硅油比高含氢量硅油显示出了更好的交联效果,且当其添加量为基础胶料质量的4%时,硫化硅橡胶显示出最好的综合性能.     

Strength analysis of a split sleeve in a pipe containing a defect

We study the decrease in the strength of a pipe containing an artificial defect. On the basis of the analytic and numerical models, we consider the influence of the structural features of a split sleeve on its load-carrying ability. We also analyze the joint operation of a sleeve and a pipe containing an artificially made axial surface defect. The results of the numerical analysis are compared with the experimental data. Translated from Problemy Prochnosti, No. 2, pp. 102–111, March–April, 2009.     

Calculation of a transient in a two-pole network with a thermistor

An analytical expression is derived which describes the variation of the thermistor temperature during a relay-effect transient process following an instantaneous change in the supply voltage in an R — R_T two-pole network.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 38, No. 3, pp. 465–472, March, 1980.     

Stress analysis of a strip with a step and a crack

Stress analysis for a strip of which widths are different at the right and left handsides is carried out for before and after occurrence of a crack at a corner of a step. The strip is analyzed as a thin plate bending problem subject to transverse bending and torsion, and as a plane eleastic problem subject to bending in the plane and uniaxial tension. The rational mapping function of a sum of fractional expressions and complex variable method are used. Stress distribution and stress intensity factors are obtained.     

Interaction between a liquid and a cylindrical body touching a wall

An exact solution is obtained for the problem of interaction between the ideal liquid homogeneously moving at infinity and streamlining a round cylinder touching a solid wall.     

Dispersion of a solute in a Poiseuille flow of a viscoelastic fluid

Gill and Sankarasubramanian's analysis of the dispersion of Newtonian fluids in laminar flow between two parallel walls is extended to the flow of non-Newtonian viscoelastic fluids (known as Phan-Thein-Tanner (PTT)). Using a generalized dispersion model which is valid for all times after the solute injection, the diffusion coefficient K_i(t) is obtained exactly and numerically for linearized and exponential forms of the PTT fluids, respectively. The analysis leads to the novel result for K₁ and K₂(t) (which is a measure of the longitudinal dispersion coefficient of the solute). It is found that the value of K₂(t) depends on the value of Deborah number (De=a measure of the level of elasticity in the fluid) whereas the value of K₁ is constant in both cases. Finally, the effect of the Deborah number on the axial distribution of the mean concentration θ_m is investigated in detail.     

Imaging a point to a line with a single spherical mirror

Methods for imaging a single point source to a line image are discussed, and a design study of single spherical mirror systems that form aberration-free line images is presented. An expression forthe ray density along the line image is derived for such systems in the cases of (i) uniform beam profiles and (ii) Gaussian beam profiles. The resulting ray density profiles are illustrated for single spherical mirror systems over a wide range of design parameters.     

Influence lines for bending under a ring load of a free shell,a shell embedded in a soft medium and a shell containing a soft core

Summary Theoretical expressions for stresses and displacements have been derived for bending under a ring load of a free shell, a shell embedded in a soft medium, and a shell containing a soft core. Numerical work has been done for typical cases with anElliot 803 Digital Computer and influence lines are drawn therefrom.

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Einflußlinien für die Biegung einer freien Schale, einer Schale in einer weichen Bettung und einer Schale mit weichem Kern

Zusammenfassung Für die Biegung einer freien Schale, einer weich gebetteten Schale und einer Schale mit weichem Kern unter einer Ringlast werden Ausdrücke für die Spannungen und Verschiebungen hergeleitet. Die Ergebnisse wurden für einige typische Fälle mit einem DigitalrechnerElliot 803 numerisch ausgewertet. Die sich ergebenden Einflußlinien wurden graphisch dargestellt.

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Nomenclature A (),B () Functions of - a, t Mean radius and thickness of the shell - E _S , _S Young's modulus andPoisson's ratio of the shell - G _c , _c Shear modulus andPoisson's ratio of the casting or core - I ₀ (r),I ₁ (r) ModifiedBessel functions of the first kind and order zero and one respectively - K ₀ (r),K ₁ (r) ModifiedBessel functions of the second kind and order zero and one respectively - p Ring load, lb/in - U, W Displacement components in the casing or core in thez andr direction - u, w Displacement components of a middle surface point in the shell - _r , _rz Radial and shearing stress components - Independent variable of infinite integrals - k [3(1–S ²)a ²/t ²]^1/4 With 13 Figures     

聚醚砜四元制膜液体系的相图计算

以Ｆｌｏｒｙ－Ｈｕｇｇｉｎｓ理论为基础，对ＰＥＳ－ＰＧ－ＮＭＰ＿Ｈ２Ｏ＿）聚醚砜丙二醇－Ｎ－甲基－２－哟咯烷酮水）四元制液体系的相图进行了计算，利用三元相图考察Ｈ２Ｏ和ＰＧ对液－液相分离的影响，在三元的理论的基础上提出了低分子量添加剂的卤元改性Ｆｌｏｒｙ－Ｈｕｇｇｉｎｓ理论，并提出了一种获得四元相图的方法，利用四元相图能较争地描述四元体系，利用改性的四元理论，能了地理解该种体系的液－液相分离行为。