Development of high‐definition aqueous polyvinylpyrrolidone photoresists for cathode ray tubes

Aqueous photoresists that are capable of higher resolutions than are currently employed by the cathode ray tube (CRT) industry were developed by combining photoactivators, which activate at shorter UV wavelengths with polyvinylpyrrolidone (PVP). Two photoactivators were synthesized: 4,4′‐diazido‐2,2′‐biphenyl disodium disulfonate (DABP), which has a maximum absorbance at 264 nm, and 4,4′‐diazido‐2,2′‐biphenylethane disodium disulfonate (DABPE), which has a maximum absorbance at 258 nm. The PVP/DABP and PVP/DABPE photoresists successfully imaged a pattern with resolution as small as 4.4 μm with photoactivator concentrations greater than 20% of the PVP concentration. Addition of silane and emulgen greatly improved the performance of the photoresists with more uniform coatings of thicknesses of up to 1.4 μm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1637–1644, 2006     

对伞花烃裂解氧化产物苯甲酸的水相酯化方法研究

对伞花烃裂解氧化产物苯甲酸与硫酸二甲酯的反应可以采用水相酯化法。实验室小试结果显示,苯甲酸的转化率平均为89.97%,苯甲酸甲酯的得率平均为83.16%;车间放大试验结果显示,苯甲酸甲酯的得率为89.00%。水相酯化法与有机相酯化法相比,甲苯的单耗降低38.69%,硫酸二甲酯的单耗下降32.14%,废水量下降35.85%,耗时减少66.67%,设备利用率和生产能力显著提高,氧化催化剂也可以得到回收。     

地下水多孔介质中胶体与污染物协同运移规律研究进展

在总结国内外地下水中污染物运移规律研究的基础上,阐述了地下水多孔介质中胶体与污染物协同运移的研究进展。讨论了胶体运移的基本过程、相关机理,探究污染物-胶体-微生物(生物胶体)协同运移的作用方式、影响因素、实验分析、模型构造,并指出该领域目前研究存在的主要问题,以及对该领域研究趋势的展望。     

Explicit numerical simulation of suspension flow with deposition in porous media: influence of local flow field variation on deposition processes predicted by trajectory methods

A new explicit numerical simulation (ENS) method based on lattice-gas automata (LGA) is introduced here for the flow of solid/fluid suspensions with deposition in porous media. The ENS method explicitly resolves the dynamics of the individual solid particles and the suspending fluid in the domain defined by the pore walls and solid particle surfaces. After describing the new method, it is applied to the study of solid/fluid suspension flow with deposition in a constriction and in a model random porous solid. This study clearly demonstrates that the deposits strongly influence the local flow fields, which in turn affect the deposition process indicating that this interplay should be modelled if accurate results are desired from trajectory methods.     

THERMAL CONVECTIVE INSTABILITY IN TRANSLUCENT POROUS MEDIA WITH RADIATIVE HEAT TRANSFER

The onset of thermal convection in a translucent porous layer is considered. Attention is focused on the effect of radiative heat transfer on the critical Rayleigh-Darcy number and the convection cell shape. If we consider the contribution of radiative heat transfer, the basic temperature profile is non-linear and the thermal convective instability is influenced by the ratio of conduction to radiation heat flux, the temperatures at the boundary surfaces, and radiative parameters such as wall emissivity, scattering albedo and extinction coefficient as well as the usual Rayleigh-Darcy number. Effects of these parameters on the onset of convective instability are investigated with the help of linear stability theory employing the Darcy's law and the radiative transport equation simplified by the P₁ approximation. The increased effective thermal conductivity due lo the radiation inhibits the onset of convection and causes increased critical Rayleigh-Darcy number and decreased convection cell size. The results of the present work may be exploited to find out the optimal diameter of aerogel pellets and the air pressure in the double pane window filled with the translucent silica aerogel granules to suppress natural convection.     

Self-emulsifiable soybean oil phosphate ester polyols for low-VOC corrosion resistant coatings

A series of soybean oil phosphate ester polyols (SOPEP) was prepared by reaction of fully epoxidized soybean oil with phosphoric acid and simultanoeous hydrolysis in the presence of a polar solvent. The polyols were characterized by determination of acid value, oxirane number, hydroxyl value, molecular weight (GPC), and FTIR spectra. These polyols with varying amounts of acid phosphate groups could be self-emulsified to form aqueous dispersions after neutralization with organic base. These aqueous dispersion showed varying degrees of stability and their appearance ranged from opaque dispersions to translucent to clear solutions. Waterborne coating compositions were prepared using these aqueous dispersions as principal components and their thermally cured film properties were studied. it was found that by careful selection and formulation, SOPEPs can be successfully used for low-VOC waterborne coating formulations. SOPEPs with 3.5% phosphate ester content showed visibly superior corrosion resistance properties.     

两种异噻唑防腐剂抑菌效果的研究

研究了两种异噻唑衍生物防腐剂的防腐最佳pH值，以及防腐剂对微生物的最低抑制浓度（MIC），确定了在洗洁精中，单一防腐剂的最低用量，对两种防腐剂在洗洁精中的混合使用亦进行了研究。     

单组分聚氨酯乳液制备及其结构与性能研究

采用预聚合法,以聚酯二元醇(PEA)、甲苯二异氰酸酯(TDI)、二羟甲基丙酸(DMPA)为基本原料合成了分子链上带有亲水基团(-COOH)的聚氯酯预聚体。以特殊的水化方式制得聚酯型水性聚氨酯乳液。讨论了温度、-NCO-与-OH的物质的量之比(R)、亲水基团含量、合成工艺分别对材料力学性能、耐水性、玻璃化转变温度(Tg)等的影响。研究发现,采用前中和工艺、在高速搅拦下将预聚物加入到水中的水化方式,当R值为1．2,羧基含量为1．6％时,合成的聚酯型水性聚氨酯乳液具有较好的贮存稳定性,且涂膜的耐水性和力学性能良好。     

多孔介质内部热质传递的等效耦合扩散模型的推导及其应用

基于Whitaker的体积平均方程，在不附加任何新的假设的基础上，对多孔介质内部热质传递的等效耦合扩散模型进行推导，得出了多孔介质内部热质传递的等效耦合扩散模型。并应用该模型对瓷质砖体干燥过程进行了数值模拟，模拟结果与实验结果十分吻合。     

吸湿介质对碳纤维增强铸型尼龙复合材料的吸湿行为及力学性能的影响

本文对碳纤维增强铸型尼龙(CF／MC 尼龙)复合材料在不同吸湿介质中的吸湿行为进行了研究。结果表明，对于纤维体积分数为10％的碳纤维增强铸型尼龙复合材料(10％CF／MC尼龙复合材料)，随着吸湿介质的PH值减小，它的吸湿率增大。同时，经过吸湿后，10％CF／MC尼龙复合材料的弯曲强度有明显的下降。随着吸湿介质的PH值减小，试样的弯曲强度下降。使用环境扫描电子显微镜观察在10％HCl溶液中吸湿的试样的剪切断口形貌，得到的结果与吸湿实验的结果一致。