仿生界面二氧化钛微球光催化剂的制备及其性能

采用模板-超声-水热法制备仿生界面TiO2微球,并采用场发射扫描电镜(FESEM)、N2吸附仪和X射线衍射(XRD)对制备的TiO2微球样品进行表征.结果表明,在乙醇溶液中水的体积分数为10％,H2O-与Ti物质的量之比为5,Ti与表面活性剂三嵌段共聚物P123 (EO20PO7oEO20)物质的量之比为46,超声作用...     

包覆HNIW用WPU/SBB复合乳液的合成与表征

以异佛尔酮二异氰酸酯(IPDI)、聚氧化丙烯二醇(PPG)、苯乙烯(St)、甲基丙烯酸丁酯(BMA)和丙烯酸丁酯(BA)等为主要原料,采用种子乳液聚合法合成了WPU/SBB(水性聚氨酯/苯丙)复合乳液;然后以此为高能炸药——HNIW(六硝基六氮杂异伍兹烷)颗粒的包覆剂和胶粘剂。采用红外光谱(FT-IR)法、X-射线衍射(XRD)法及差示扫描量热分析(DSC)法等手段对WPU/SBB复合乳液的结构进行了表征,并采用扫描电镜(SEM)、特性落高值(H50)和X-射线光电子能谱(XPS)法等分析了WPU/SBB复合乳液对HNIW的包覆效果。结果表明:包覆后HNIW的H50由13.6 cm升至34.8 cm,说明该环保型WPU/SBB复合乳液对HNIW具有明显的降感作用。     

Curing Characteristics and Thermal Properties of Epoxidized Soybean Oil Based Thermosetting Resin

Epoxidized soybean oil (ESO) was thermally cured using methylhexahydrophthalic anhydride (MHHPA) curing agent in the presence of 2-ethyl-4-methylimidazole (EMI) catalyst. The curing characteristics of ESO/MHHPA/EMI systems were characterized using Fourier transform infrared spectroscopy (FTIR), a dynamic mechanical analyzer (DMA) and a differential scanning calorimeter (DSC). FTIR spectra showed that the polyesterification rate in ESO/MHHPA/EMI systems increased with increasing of the catalyst concentration. DSC thermograms indicated that EMI-catalyzed ESO/MHHPA systems experienced enthalpy relaxation at low EMI concentration whereas the extent decreased with increasing of the EMI concentration. There is a direct relationship between the degree of conversion and crosslink density of the thermal cured ESO/MHHPA/EMI systems with EMI concentration. The curing characteristics of thermal curable ESO thermosetting resins were found to have influence on the thermal properties of the ESO systems. It was determined that the glass transition temperature (T _g) and storage modulus (E′) of cured ESO increased with increasing the EMI concentration whereas the damping properties of the ESO/MHHPA/EMI systems exhibited the reverse trend. It was found that the thermally curable ESO thermosetting resins experienced a two-stage thermal decomposition process.     

核化工与核燃料工程专业“3＋1”人才培养模式的探索

根据核化工与核燃料工程专业人才培养目标,参照其他工科专业人才的培养模式,结合保密性强、专业性明显的＂核＂特色,制定了适合国防、核工业对核化工与核燃料工程专业人才需求的＂3＋1＂人才培养模式,并进行了探索与实践,取得了较好的成效。     

聚丙烯腈/磺化聚苯醚质子交换膜的制备和性能

采用溶液共混浇铸法制备了一系列的聚丙烯腈/磺化聚苯醚(PAN/SPPO)共混质子交换膜.结果表明,磺酸基团成功引入交换膜,共混膜有较好的相容性,没产生相分离,PAN/SPPO共混膜的吸水率和溶胀率明显降低,其热性能稳定.与纯SPPO膜相比,虽然英质子传导率有所下降,但都在10-2～ 10-3S/cm数量级范围内,究全可...     

Aggregation behavior of poly(methacrylic acid) with cucurbit[7]uril and the effect of ammonia ions on aggregation

The interaction between poly(methacrylic acid) (PMAA) and cucurbit[7]uril (CB[7]) in aqueous solution were investigated by dynamic light scattering (DLS), fluorescence techniques, UV-spectrophotometer, and resonance light scattering (RLS). The experimental results show that the aggregates were formed between CB[7] and H⁺ of PMAA by the hydrogen bonding interaction that increases with increasing the concentration of CB[7], which leads to the formation of the larger aggregates. Interestingly, PMAA has temperature sensitivity with the addition of CB[7] by UV-spectrophotometer and DLS. The pH of the solution of PMAA appears a inflection point with increasing the concentration of CB[7] comparing with the increase of the electrical conductivity all the time with the addition of CB[7]. In addition, in order to investigate the effect of cation on the size of the aggregates and avoid the effect of other anions at the same time, the dilute ammonia was added into the solution of PMAA. The experimental data show that the size of the aggregates increases with adding CB[7] because CB[7] could combine with both NH₄⁺ by the electrostatic and iondipole interactions and H⁺ by the hydrogen bonding interaction, and a possible model is proposed to explain the host-guest interactions between PMAA and CB[7].     

微胶囊化聚磷酸铵的制备及表征

以聚磷酸铵(APP)为芯材、三聚氰胺甲醛树脂(MF)为壁材,用原位聚合法制备出微胶囊化聚磷酸铵(PMCAPP),采用激光粒度仪、扫描电镜、红外光谱、X射线能谱仪(EDS)、热重分析及吸湿试验等仪器及手段进行表征。结果表明,PMCAPP粒径增大,粒径分布变窄,吸水率由15%(质量分数,下同)降低到7%;热分解性能有所提高;聚丙烯(PP)/PMCAPP的阻燃性能优于PP/APP的,当PMCAPP的添加量达到15%时阻燃性能最佳,极限氧指数(LOI)值达到36.0%。     

单相方波逆变器中GTR的驱动与缓冲

本文简单介绍了大功率晶体管ＧＴＲ的特性及解决驱动与缓冲问题的途径，重点分析了在研制单相方波逆变器时所使用的驱动电路与缓冲电路的工作原理及工作特性。     

电力系统复杂故障通用算法的研究

我们用补偿法原理开发出电力系统复杂故障的通用计算软件。本文着重讨论其核心部分－故障后补偿导纳矩阵和故障前端口阻抗矩阵的形成，并推导出了有关计算公式。此程序可灵活地修改运行方式，对故障类型、故障特殊相、故障过渡电阻处理简便，易于编程。可满足电力系统继电保护整定计算和事故分析的需要。     

Control and enhancement of permselectivity of membrane‐based microcapsules for favorable biomolecular transport and immunoisolation

The success of membrane‐based, cell‐encapsulating microcapsules depends on the membrane permselectivity that provides efficient inward transport of nutrients, therapeutic protein egress, and complete exclusion of immunoglobulins. Microcapsules with a calcium crosslinked alginate core and a genipin‐crosslinked chitosan alginate (GCA) were prepared with good control over size, membrane thickness and density. Importantly, in this study, we report a novel approach of using three relevant biomolecules and investigating the effects of the membrane characteristics (thickness and density) and microcapsule size on biomolecular mass transport across the GCA microcapsules using mathematical models based on a balance of the chemical potential. Scaling analysis was used to interrelate the membrane thickness, chitosan–alginate reaction rate constant, and diffusion coefficient. The resistance to diffusion of the three biomolecules increased with membrane density and thickness. Interestingly, swelling in the large microcapsules resulted in an increase in permeability, allowing larger biomolecules (immunoglobulin and carbonic anhydrase) to diffuse more readily. In the case of the smaller biomolecule, vitamin B₁₂, a shorter diffusion path length in smaller microcapsules allowed better ingress. When compared with other microcapsules, the GCA microcapsules possess improved permselectivity for them to allow diffusion of small nutrient molecules and proteins, whereas completely excluding antibodies. Also, these results elucidate the importance of membrane properties and microcapsule size to realize favorable transport of biomolecules. © 2011 American Institute of Chemical Engineers AIChE J, 2011