乙烯-醋酸乙烯酯的结构与降凝性能的关系

用溶液聚合法合成了各种结构的乙烯-醋酸乙烯酯共聚物(EVA)降凝剂,考察了它们的结晶性质、溶解性质和降凝效果.由实验得到以下结论:EVA降凝剂的CH2链上只有远离极性基团的碳原子能够参与结晶.当参与结晶的碳原子数约等于原油中蜡的平均碳原子数的3/4时,EVA降凝剂的降凝效果最好.EVA降凝剂的相对分子质量分布的宽窄对降凝效果的影响不大,平均相对分子质量在1.2×104时降凝效果较好.     

基坑的双排桩支护设计及变形规律

以济南市槐荫区某基坑工程进行双排桩支护设计为例,分别采用有限差分数值软件中弹塑性实体单元和线性桩单元模拟开挖-支护-施工全过程,且考虑桩土相互作用并进行三维动态分析。对基坑坡面水平位移、桩身弯矩、桩身剪力等变化规律进行研究,分析双排桩支护体系的受力机理。通过土体力学参数、桩径、桩长、桩距、连梁等设计参数对基坑变形影响的敏感性进行对比,并就“实体”和“结构”单元桩的计算结果进行比较。研究表明,模拟过程能较好展示双排支护桩施工过程的受力机理,且计算精度较高;不可控参数中土体的黏聚力、摩擦角以及可控因素中的桩身长度、排桩距离等对支护效果影响较大,计算结果可为双排支护桩设计参数选取提供参考。     

乙酰胺-尿素-NaBr熔体中电沉积Tb-Mg-Ni合金的研究

在353?K的乙酰胺-尿素 NaBr熔体中，Ni（Ⅱ）一步不可逆还原为金属Ni,测得在Pt电极上α为0.21和D0为1.15×10-8?cm2•s-1；Cu电极上α为0.18和D0为1.44×10-6?cm2•s-1.Tb（Ⅲ）和Mg（Ⅱ）不能单独还原为Tb和Mg，但是可以被Ni（Ⅱ）诱导共沉积.由恒电位电解法得到非晶态的Tb Mg Ni 合金膜.合金中Tb的含量随着阴极电势的负移先增大而后减小，随Tb（Ⅲ）/ Ni（Ⅱ）摩尔比增大而增大，Tb的最大含量可达87.88%；Mg的含量随着阴极电势的负移而增大，最大可达12.78%，在Tb（Ⅲ）/Ni（Ⅱ））摩尔比为3.4/1，Mg（Ⅱ）/Ni（Ⅱ）摩尔比为8/1时，Mg/Ni原子比为2/1，符合Mg2Ni储氢合金的组成.     

A study on interfacial mechanisms and structure of poly(ethylene-co-methacrylic acid)/copper with reflection–absorption infrared spectroscopy

The interfacial mechanism and structure of poly(ethylene-co-methacrylic acid)/copper were investigated using reflection-absorption infrared spectroscopy (RAIR). Based on IR spectrum of EMAA/copper, a strong absorption peak appearing at approximate 1,600 cm⁻¹ is attributed to the asymmetric stretching vibration of COO^― (υCOO_as^―) and a relatively weak absorption band at 1,375 cm⁻¹ is assigned to the symmetric stretching vibration of COO^― (υCOO_s^―). Therefore, it can be determined that copper interacts with EMAA through a strong ionic interaction and carboxylate structure is formed in the interfacial regions. And, according to the band intensities of carboxylate stretching modes and different sensitivities of RAIR to perpendicular and parallel transition moments, it can be concluded that EMAA is absorbed onto a copper substrate with a configuration in which the twofold axis of the C_2υ point group for carboxylate group inclines certain degree from the normal to the surface. In addition, the interfacial carboxylate structure of EMAA/copper is confirmed to be a monodentate one through calculating the difference (Δυ)between the asymmetric carboxylate stretch (υCOO_as^―) and the symmetric stretch (υCOO_s^―).     

Anisotropic properties of aligned SWNT modified poly (methyl methacrylate) nanocomposites

The poly (methyl methacrylate) (PMMA)/single-walled carbon nanotube (SWNT) composites with good uniformity, dispersion and alignment of SWNT were fabricated in an improved figuration process. The semidried mixture was stretched along one direction at a drawing ratio of 50 before it was dried, and then folded along the same direction stretching repeatedly for 100 times. The transmission electron microscopic (TEM) observation demonstrated that SWNT in the PMMA/SWNT composite tends to align in the stretching direction owing to a torque exerting on it in the stretching process. The electrical and mechanical properties of PMMA/SWNT composite were studied as a function of SWNT orientation and concentration. The aligned SWNT modified PMMA/SWNT composite presented highly anisotropic properties. The experimental results showed that the electrical conductivity and mechanical properties of composite rise with the increase of SWNT concentration, and that composite films showed higher conductivity and higher mechanical draw ratios along the stretched direction than perpendicular to it. The thermogravimetric analysis (TGA) revealed that embedding the SWNTs into the PMMA matrix also improves the thermal stability of the composite.     

双（多）基地声纳浮标系统在反潜中的应用研究

在双基地声纳系统中，根据能量关系推导出双基地声纳系统最大可探测范围的数学模型；在此基础上，讨论了用双（多）基地声纳浮标系统布放直线阵、圆形阵时的阵形宽度、搜索面积及所需浮标数，并将之与传统被动浮标阵进行了比较．结果表明：采用双（多）基地浮标阵可以在一定程度上节省浮标数，提高了浮标的使用效率．     

新型钢筋阻锈剂的合成及其阻锈性能的研究

合成了一种舍有氨基和菝基的有机阻锈刑，并用硬化砂浆法研究了该阻锈剂在砂浆中含有氯离子的条件下对钢筋锈蚀的抑制作用，同时与常用的亚硝酸盐的阻锈效果进行了比较。结果表明，该新型阻锈剂能够有效地阻止钢筋表面钝化膜的破坏，比亚硝酸盐具有更好的阻锈效果。     

水基淬火介质冷却特性对材料淬火显微组织及开裂倾向的影响

提出将淬火介质冷却特性曲线与材料的奥氏体连续冷却转变动力学曲线相结合，来选择材料的淬火介质，获得合适的显微组织并控制材料淬火过程中的变形、开裂倾向。实验证明了水基淬火液的冷却特性的可调性。指出同一材料在相同的奥氏体化条件下采用不同冷却特性的淬火介质淬火时，材料淬火后的显微组织形态、物相构成的差别及其对开裂倾向的影响。将材料连续冷却转变动力学曲线与淬火介质冷却特性曲线直接关联起来．为研制新型水基淬火介质提供了新的试验方法。     

电磁场作用下制备表面复合材料的研究

在利用高频磁场制备表面自生复合材料中，对合金熔体在各个温度区间施加磁场时的凝固行为进行了研究。通过对Al—16wt％Si合金熔体的凝固温度区间进行合理的控制，制备出初生硅相向边沿有效偏聚的表面复合材料：中心部分为洁净的共晶区，外表面富集初生硅颗粒。实验结果表明，对Al—16wt％Si合金而言，施加磁场的最佳温度区间为580℃-600％，在磁场作用时间为20s时，即能实现对硅颗粒的有效偏聚。     

Monitoring the Synthesis and Composition Analysis of Microsilica Encapsulated Acetylacetonatocarbonyl TriphenylphosphinerhodiumCatalyst by Inductively Coupled Plasma (ICP) Techniques

A novel technique to monitor the synthesis process of encapsulated acetylacetonatocarbonyl triphenylphosphinerhodium within a microsilica nanoshell has been studied using inductively coupled plasma (ICP) techniques. Nanospheres sized around 50-100 nm were obtained and ICP was used to quantify the exact composition of rhodium, phosphorous, and silicon with differing digestion solvents. In addition, ICP was used to detect rhodium and phosphorous in the nano core-shell catalysts as a quality control procedure