新型蔗糖基聚羧酸高效减水剂的合成与性能

以自制甲基丙烯酸蔗糖酯（MASE）、丙烯酸（AA）、甲基丙烯酸（MAA）、烯丙基磺酸钠和烯丙基聚乙二醇（A PEG ）为原料,以过硫酸钾为引发剂,自由基共聚法合成蔗糖基聚羧酸高效减水剂。研究了反应时间、蔗糖酯含量及引发剂用量对蔗糖基聚羧酸高效减水剂性能的影响。并通过流动度测试、红外光谱表征及黏度对减水剂的结构与性能进行了分析与比较。各组分物质的量nAA ：nMAA ：nSAS ：nAPEG ：nMASE ＝3∶1∶2∶1∶0．2,MASE含量为4．9wt．％,引发剂为单体用量1．9wt．％,反应时间为5h时合成的减水剂性能最好。在水灰比为0．29,折固掺量为0．3w t ．％,水泥净浆流动度达到340mm。     

黑茶乙醇提取物以及其抗氧化性的研究

目的：研究黑茶的抗氧化性作用.方法：采用溶液超声波提取法提取出黑茶的乙醇提取物,再用分光光度法测定不同浓度的黑茶乙醇提取物对羟基自由基、DPPH自由基的抑制率以及还原能力.结果：在一定范围内,随着黑茶提取物的含量增加其对自由基的抑制作用以及还原能力都逐渐增强.当提取液体积为0.20 mL时,提取液对羟基自由基的抑制达到最大为51.70％.在黑茶提取液体积达到0.16 mL时,其对DPPH自由基的抑制达到最高为87.44％.黑茶提取物的还原能力,在一定浓度范围内呈现正相关性A=0.040 3＋2.007 4V,相关系数为0.999 6.结论：黑茶乙醇提取物具有较好的抗氧化性.     

两亲嵌段共聚物(聚苯乙烯-b-聚己内酯)的合成与表征

采用原子转移自由基聚合法合成聚苯乙烯,经过四氢铝锂还原,制得单羟基封端的聚苯乙烯.与己内酯进行开环反应制备AB型两亲性嵌段共聚物(聚苯乙烯-b-聚己内酯),并通过凝胶渗透色谱和红外光谱对聚合物进行了结构表征.研究表明,将此两亲性嵌段聚合物加入到环氧树脂/甲基四氢苯酐固化剂混合体系中,经过反应诱导相分离发现,该嵌段在环氧基体中发生微观相分离,相分离尺寸控制在纳米尺度,可以作为环氧改性剂使用.     

铝蜂窝负载锰基催化剂的制备及其在室温下去除低含量甲醛的性能

采用水热共沉淀法和原位氧化还原法制备MnO_x/MgAl类水滑石(Mg₃Al₁-LDHs)催化剂,以水玻璃作为黏结剂将其负载到铝蜂窝上,用于室温下去除甲醛。通过X射线衍射(XRD)、热重分析(TG)、X射线光电子能谱(XPS)、N₂吸附-脱附、傅里叶变换红外光谱(FT-IR)等手段进行表征。表征结果表明：MnO_x/Mg₃Al₁-LDHs具有典型类水滑石结构,大量结合水和羟基; MnO_x为δ-MnO₂和Mn₃O₄的混合物,具有高比例Mn⁴⁺/Mn³⁺和丰富的吸附氧。实验结果表明：室温(25 ℃,相对湿度60%)下反应4 h后,MnO_x/Mg₃Al₁-LDHs催化剂可将甲醛质量浓度由1.30 mg/m³降至0.10 mg/m³以下,且经过8次和连续15 d实际测试,表明催化剂具有良好的稳定性和甲醛去除效果。MnO_x/Mg₃Al₁-LDHs催化剂最佳负载量(质量分数)为5%,风扇最佳功率为10 W,空气中湿度对甲醛去除效果影响较小,该催化剂具有较强水分抵抗能力,反应温度提升会较大程度提高甲醛去除效果。     

Radiation crosslinking of linear polyethyleneimine-based nanoparticles grafted to poly(glycidyl methacrylate) via trimethylolpropane triacrylate as potential electronic packaging material

Linear polyethyleneimine (L-PEI)-based nanoparticles were synthesized via hydrolysis of poly-2-methyl-2-oxazoline (PMeOx), which was prepared by cationic ring-opening polymerization of the oxazoline five-membered ring. Herein, a kinetic study of the ring-opening polymerization reaction is discussed. The nuclear magnetic resonance spectrum of PMeOx verified the presence of repeating units and terminal groups in the polymer's structure. Molar ratios of PEI and PMeOx were characterized using size exclusion chromatography with low-polydispersity polymer chains as the controlled polymerization reaction. PEI and PMeOx exhibited narrow particle size distribution with hydrodynamic radii of 89 and 67 nm, respectively, as determined via dynamic light scattering analysis. In addition, atomic forces and scanning electron microscopy were used to investigate the topography of the PEI thin films. Poly(glycidyl methacrylate) P(GMA) was grafted onto a PEI chain in the presence of trimethylolpropane triacrylate (TMPTA) as the crosslinking agent to synthesize the P(GMA–PEI–TMPTA) tripolymer via free radical polymerization using gamma irradiation. The thermal characterization of the P(GMA–PEI–TMPTA) tripolymer was conducted using thermogravimetric analysis and differential scanning calorimeter. Generally, the thermal stability of the P(GMA–PEI–TMPTA) tripolymer was improved at low-glycidyl methacrylate concentrations. The prepared tripolymer could be used as effective packaging materials for electronics industries.     

粘土砂湿型用醇基涂料及其应用

粘土砂湿型铸造,铸件表面容易产生粘砂。某厂采用粘土砂湿型生产拖拉机铸件,也遇到了铸件表面粘砂的问题。通过不断选择醇基涂料悬浮剂,调整涂料的配比,最后采用SN-1悬浮剂,经试验和应用取得较好的效果。     

Knowledge and Belief: Some Clarifications

The notions of knowledge and belief play an important role in philosophy. Unfortunately, the literature is not very consistent about defining these notions. Is belief more fundamental than knowledge or is it the other way around? Many accounts rely on the widely accepted strategy of appealing to the intuition of the reader. Such an argumentative methodology is fundamentally flawed because it lets the problems of common sense reasoning in through the front door. Instead, I suggest that philosophical arguments should be based on formal-computational models to (a) reduce the ambiguities and uncertainties that come with intuitive arguments and reasoning, and (b) capture the dynamic nature of many philosophical concepts. I present a model of knowledge and belief that lends itself to being implemented on computers. Its purpose is to resolve terminological confusion in favor of a more transparent account. The position I defend is an antirealist naturalized one: knowledge is best conceived as arising from experience, and is fundamental to belief.     

正己烷裂解反应自由基模型的理论研究

采用量子化学法研究了模型化合物正己烷裂解过程,并计算其动力学参数。依据自由基理论,建立由216个基元反应组成的正己烷裂解反应自由基模型,用CBS-QB3法计算链引发和终止反应动力学参数,用MPW1B95/6-311+G(2d,2p)法计算链增长反应动力学参数。根据动力学参数计算结果,忽略相对不重要的反应,将模型简化为160个基元反应。模拟计算表明,在相同的裂解条件下,简化模型模拟结果与完整模型模拟结果一致,各组分相差不大于0.1%wt;建立的动力学模型对主要产物收率预测较好,与实验值相差小于0.7%wt,可正确地预测正己烷裂解产物的组成和各组分含量沿反应管长度的分布,为进一步研究复杂的烃裂解过程提供了基础。     

钛基亚氧化钛电极电化学降解性能研究

采用SEM、EDS对钛基亚氧化钛电极进行形貌和成分表征,用线性极化曲线法和循环伏安法测试电化学性能,通过降解模拟污水测试降解性能以及用荧光光谱法检测自由基。结果表明,钛基亚氧化钛电极上不能发生直接氧化反应,但是电极析氧电位可达2.18 V(vs.SCE),并且检测到生成大量·OH,是一种类似于Ti/SnO_2的惰性电极,在Na Cl和Na2SO4电解质溶液中电流效率分别达40.95%和22.52%,降解效果优于Ti/SnO_2和Ti/Ru Ir电极。     

Kinetics of styrene emulsion polymerization with a stable monomer radical

We have analyzed the electrical conductivity of a linear high charge density polyelectrolyte aqueous solution, finding that the counterion association order follows the same pattern as that described for a cyclic monomeric polyelectrolyte, i.e. NO > Br^? > Cl^? > F^?. However, these counterions interact in a very different manner with this polyion, making Eisenberg's relationship inapplicable in this system. Consequently, an alternative method is proposed for treating data.