水溶性MA/AA/AMPS聚羧酸高效陶瓷减水剂的制备及其性能

以马来酸酐（MA）、丙烯酸（AA）和2-丙烯酰胺基-2-甲基丙磺酸（AMPS）为单体,采用水溶液聚合法制备了一种MA/AA/AMPS聚羧酸高效陶瓷减水剂.通过单因素实验以考察合成条件对聚合反应的影响,采用FT-IR和POM分别表征其官能团结构及分散情况,并进一步利用SEM图片观察陶瓷坯体料浆形貌.结果表明,水溶性MA/AA/AMPS聚羧酸高效陶瓷减水剂的合成条件对其性能有很大影响.各单体的摩尔数、引发剂的用量、聚合温度等因素都在一定程度上影响陶瓷坯体料浆体系的性能.     

Corrosion behavior of ultrafine-grained AA2024 aluminum alloy produced by cryorolling

The objectives of this study were to produce ultrafine-grained (UFG) AA2024 aluminum alloy by cryorolling followed by aging and to evaluate its corrosion behavior. Solutionized samples were cryorolled to ~85% reduction in thickness. Subsequent aging resulted in a UFG structure with finer precipitates of Al₂CuMg in the cryorolled alloy. The (1) solutionized and (2) solutionized and cryorolled samples were uniformly aged at 160℃/24 h and were designated as CGPA and CRPA, respectively; these samples were subsequently subjected to corrosion studies. Potentiodynamic polarization studies in 3.5wt% NaCl solution indicated an increase in corrosion potential and a decrease in corrosion current density for CRPA compared to CGPA. In the case of CRPA, electrochemical impedance spectroscopic studies indicated the presence of two complex passive oxide layers with a higher charge transfer resistance and lower mass loss during intergranular corrosion tests. The improved corrosion resistance of CRPA was mainly attributed to its UFG structure, uniform distribution of fine precipitates, and absence of coarse grain-boundary precipitation and associated precipitate-free zones as compared with the CGPA alloy.     

Expression and function of a new angiogenic factor AA98 target molecule at the maternal-embryonic boundary of rhesus monkey

The target molecule of monoclonal antibody AA98 (AA for short) is a new vascular endothelial cell related factor and plays a role in angiogenesis as indicated by the previous data. To investigate its role in angiogenesis and placentation in primate, we examined its expression in the implantation sites on D17, 19, 28 and 34 of gestation in rhesus monkey by immunohistochemistry and Western immunoblot. Western blot analysis showed that the primary antibody used in this study was specific for its epitope. AA protein was mainly expressed in small blood vessels and in some cytotrophoblast cells. The AA staining was found mainly in the endothelial cells and vascular small muscle. This observation supported the AA‘s role in angiogenesis. AA was spatio-temporarily expressed in cytotrophoblasts: weak in proliferating trophoblast within cell column and endovascular trophoblast, strong in trophoblastic subpopulation within the basal plate and vascular trophoblast; AA staining within the basal plate was down-regulated during early placentation. The shift of AA98 expression in extravillous trophoblasts suggestes a role of this new factor during the course of cytotrophoblast metastasis and spiral artery remodeling. The spatio-temporarily expression indicats that AA98 could be also used as a trophoblast cellular marker to characterize the acquisition of a vascular endothelial and invasive phenotype.     

含时调制的Jaynes-Cummings模型的AA相位

基于含时调制的Jaynes Cummings模型的 SU(2 )群结构 ,利用规范变换 ,求得该系统的AA相位 .     

基于正交试验的高强高导AA8000系铝合金的优化设计

采用正交试验进行合金成分优化设计,运用二元搭配表得到最优的合金成分,研究了Fe、Si含量对AA8000系铝合金性能的影响.采用扫描电子显微镜（SEM）,X射线衍射仪（XRD）,金相显微镜（OM）和透射电子显微镜（TEM）,研究了Fe、Si及其交互作用对铝合金微观组织的影响.探究了不同的组织相貌对铝合金电学性能及力学性能的影响,并从理论上分析了Fe、Si的交互作用机理.研究结果表明：由正交试验得到最优的合金元素组成,当Fe的质量分数为0.4%,Si的质量分数为0.2%时,合金具有较高的导电率和较高的强度;Fe、Si存在交互作用,Fe与Si可以形成Al₈Fe₂Si三元中间相,减少了Si对铝合金导电性能的不利影响.     

超高吸水性树脂的合成研究

采用丙烯酰胺与丙烯酸 (钠 )共聚体系 ,以过硫酸胺 (NH4) 2 S2 O8为引发剂 ,N ,N—双亚甲基丙烯酰胺为交联剂 ,得到轻度交联的高分子化合物 ,用聚乙烯醇改善其三级结构 ,制得超高吸水剂 ,吸收含 0 .9%的NaCl盐水达自身重量的近百倍 .     

从第36届世锦赛探析世界男子自由体操的发展趋势

通过分析第36届体操世锦赛优秀运动员自由体操整套动作的结构和特点，研究了男子自由体操的发展趋势．结果表明：整套动作的发展潮流是以单个或合成SE组开场．中串多以三个直体空翻连续转体1260°以上来提高连接价值．最后以E组或D＋E的挂串连接结束．文中还简要分析了目前我国男子自由体操存在的差距及其原因．     

快速凝固AA8009耐热铝合金及其焊缝的耐腐蚀性能

通过剥落腐蚀实验、极化曲线测定和腐蚀形貌观察，研究了AA8009合金（Al-8．5Fe-1．3V-1．7Si）及其氩孤焊和电子束焊件的耐腐蚀性能，并与LF6和2024合金的耐腐蚀性能做了比较。实验结果表明：快速凝固AA8009耐热铝合金的耐腐蚀性能是最好的，这是由于该合金具有弥散分布、高含量的Al12（Fe，V）。Si增强相，该相的存在大大减少了合金形成腐蚀原电池的可能性。而LF6和2024合金由于在晶界处有析出相形成而降低了它们的耐蚀性。同时，AA8009合金电子束焊缝的抗蚀性要明显优于氩孤焊的抗蚀性。     

哈密顿不依赖时间的系统的AA几何位相

讨论哈密顿不依赖于时间的系统的非绝热几何位相，结果证明：对于这样的系统，除了定态是几何位相为零的循环态之外，循环态条件仅在如下情况满足：①两能级系统或只有两个本征态的几率幅不为０；②系统的激发能是可公度的．如果循环态存在，系统的非绝热几何位相与初态｜ψ（０）＞有关     

丙烯酸与尼龙-6接枝共聚反应的研究

本文用乙酰丙酮锰（Ｍｎ（ａｃａｃ）３）为引发剂,丙烯酸为单体、对尼龙－６短纤维进行化学接枝共聚反应．结果表明、纤维的接枝率随单体浓度、引发剂浓度、反应时间、反应温度不同而异、接枝后的纤维、其吸湿性、抗静电性都有所提高