Versatile 2-amino-4-substituted-1,3-thiazoles: synthesis and reactions

Syntheses and reactions of 2-amino-4-substituted-1,3-thiazoles are reviewed in a formal way. The title compounds are most easily accessible by various approaches, and even waste-free solid-state procedures have been developed. The substitution in 4-position has synthetic reasons and therefore most interest accumulates around these derivatives of 2-aminothiazole. The high reactivity of both the amino group and the positions 3 and 5 of the 1,3-thiazole ring are used for numerous syntheses in a comprehensive way. The reactions are subdivided in groups that cover reactions at the amino substituent without touching the thiazole ring, reactions which involve both nitrogens in the formal amidine system to give thiazolo-pyrimidinones and -imidazoles as well as more involved polycondensed N,S-heterocycles with multiple possibilities for substituents, and substitution reactions at the 5-position of the thiazole ring. Most of the imaginable reaction types have been successfully applied and used, as many of the synthesized compounds exhibit interesting biological activity in various fields.     

模2n加法最佳线性逼近关系研究

该文研究了模2n加法运算的最佳线性逼近问题。利用权位分量函数的线性逼近关系,该文首先给出了模2n加法最佳线性逼近相关值的计算公式。其次通过递归构造得到了模2n加法最佳线性逼近集的生成方法。该文的研究从理论上更清楚地刻画了二元模2n加法最佳线性逼近的内在规律,有助于更好地利用该线性逼近关系实现对实际密码算法的有效分析。     

聚落的再现——对伍重、西扎的比较阅读

本文从设计方法的角度,以聚落研究为基础,对当代建筑师伍重、西扎的作品进行比较阅读。在某种程度上伍重和西扎都从聚落中获得了启示,但最终两位建筑师的作品分别以宏大叙事和小叙事的角度再现了聚落的场景。     

常用矢量波函数的坐标变换关系

本文导出标准直角、圆柱和圆球矢量波函数的坐标变换关系,为实际使用提供了方便。     

反应合成TiB_2工艺研究

本文就TiB2粉末的反应合成工艺进行初步探讨,采用XRD分析技术对在不同温度下的试样进行相结构组成分析;由气相色谱法测定粉末的C和O2等杂质;通过电子探针对粉末进行扫描形貌（SEM）观察．实验表明：原料配碳（Cm）和合成温度（T）是影响粉末质量的关键因素．     

辐射事故中确定性健康危害的剂量学评价方法(Ⅰ)

确定性效应是辐射事故中主要关心的健康危害。辐射事故照射,除大剂量急性照射情况外,更多的还有受照延续时间不等、照射水平不一的多次受照情况,甚至尚有数天内连续受照的。本文从辐射效应的“线性-平方”模型出发,借助目前已经掌握的确定性效应的剂量阈值,针对剂量的不同时间分布,集中探讨低LET辐射事故中评价确定性健康危害的剂量学方法。引用了分割照射和延续照射的外推剂量概念,提出了外推剂量可加原理和等外推剂量等效应原理。     

高频板制作关键技术探讨

高频板涉及的技术相对较高，相关制作、检测设备和技术人员都是企业在跨越的一道难题，所以应充分考虑市场和技术、设备能力等方面的因素尤为重要。通讯基站应用的高频板市场方面，在中国及另一些发展中国家市场需求相对旺盛，值得关注。文章重点介绍高频板内层-压合层间控制和钻孔-电镀孔粗控制两个方式制作关键点，以供参考和建议。     

Antioxidative activities of tocotrienols on phospholipid liposomes

Antioxidative activity of tocotrienol (Toc3) was studied in the oxidation of dilinoleoylphosphatidylcholine (DLPC) liposomes. The objective was to measure the differences in the antioxidative activities betweenα-Toc3 andα-tocopherol (α-Toc), and betweenγ-Toc3 andγ-Toc. When each antioxidant was added to the already prepared DLPC liposome solution, the antioxidative activity of Toc3 was larger than that of Toc. However, when incorporated into the liposomal membrane, the antioxidative activities of Toc3 and Toc were the same and were intermediate between those of the added Toc3 and Toc. When added to the liposome solution, the consumption of Toc3 during the induction period was larger than that of Toc. When incorporated into the liposomal membrane, the consumptions of Toc3 and Toc were the same and were intermediate between those of the added Toc3 and Toc. These results suggest that the reactions of Toc3 and Toc with phospholipid peroxide within the membrane are inhibited to a different degree depending on the dosing manner of Toc3 and Toc. Namely, the degree of inhibition decreases in the following order: Toc(added)> Toc(incorporated)= Toc3(incorporated)> Toc3(added).     

广义递推T矩阵算法及其应用

递推Ｔ矩阵算法是一种计算散射问题的新型方法。本文对广义递推Ｔ矩阵算法的计算公式作了简单的推导并得到了其表达式。还论述了该方法与系列算法中其它方法之间的联系及优越性，并对波函数的加法定理进行了推广，证实了该定理同样适用于虚宗量的情况，将两方面的内容加以结合，应用于损耗介质散射场的计算。同时还计算了原文献中尚未涉及的媒质问题。最后，给出了二维条件下，该方法ＣＰＵ的计算时间与未知数的关系的图示。     

改善Mg-Zn-Zr系变形合金铸锭塑性的研究

Mg-Zn-Zr系合全变形制品是当前使用较为广泛的高强轻合金材料,但是,因其合金铸锭塑性较差,故它的挤压制品、锻件及板材等得用一次挤压棒材和带板等,再通过二次压力加工方法来制得。本文研究了向Mg-Zn-Zr系合金中添加Y、Nd来改善合金铸锭塑性,从而达到用一次变形加工来获得挤压制品、锻件及板材方法的可行性问题,结果表明;在Mg-Zn-Zr系的MB15合金中添加1％Y和1％Nd,因其铸锭晶粒被细化,而可用铸锭直接制取挤压制品、锻件与板材,所获得的制品室温机械性能优于MB15合金,腐蚀性能则与MB15合金相当。