用硼酸作催化剂一锅法合成双（二氢化嘧啶酮-4-基）苯

A simple effective synthesis of bis(dihydropyrimidinone-4-yl)benzene derivatives, using boric acid as catalyst,from isophthalic aldehyde or terephthalic aldehyde, 1,3-dicarbonyl compounds and urea or thiourea in glacial acetic acid was described. As the expansion of the classical Biginelli reaction, this method has the advantage of excellent yields 83%-94% and short reaction time 0.5-1.5 h.     

Self－assembly of Novel Hetero[3]rotaxane, [2]Rotaxanes and [2]Catenane

One linear template 13 and one cyclophane template 15, both incorporating two electron rich 1,4‐dialkoxybenzene units and one diamide unit, have been synthesized. By utilizing donor‐acceptor interaction and/or intermolecular hydrogen bonding assembling principles, one novel hetero[3]rotazane 22·4Cl, possessing one neutral and one tetracationic ring components, has been synthesized from 13, through neutral [2]rotaxane 21 as intermediate. With 15 as template, tetracationic [2]catenane 23·4PF₆ was assembled by using donor‐acceptor interaction, but no neutral [2]rotaxane could be obtained under the typical conditions of hydrogen bonding assembling principle. The interlocked supramolecular compounds have been characterized and their spectral properties are investigated.     

强流电子束泵浦XeCl准分子激光动力学模型

强流电子束泵浦XeCl准分子激光动力学模型由三部分组成,即电子束能量沉积的计算;电子温度、电子反应速率的计算和化学/激光动力学。这个模型可以准确地预报小信号增益、吸收等激光特征量的时间变化规律。 该模型是在文献[1]、[2]、[3]报导的动力学模型的基础上提出的。采用四阶龙格_库塔法在VAX—11/780机器上进行数值求解。 计算给出XeCl准分子激光反应过程中各种粒子浓度、小信号增益、吸收、输出光强、激发速率以及平均电子能量随时间的变化规律。计算结果表明本征效率是激发速率,电流密度和工作气体(Ne/Xe/HCl)的各分压比的函数。 该模型可为高功率准分子激光器的研制提供设计参数和最佳实验条件。     

四唑及其衍生物的理论研究（6）

对7个肼基四唑衍生物进行了HF／6－31G水平的几何构型全优化及MP2／6－31G／／HF／6－31G水平的总能量计算．结果表明，四唑环基本上取平面构型，肼基不与环共面．键长与重叠布居之间不存在平行关系．环上N1和N4原子荷负电多、利于质子化．1H．肼基四唑的HOMO－LUMO能级差（△E）较2H式的大，中性分子的△E教相应的负离子的大．还计算研究了7个标题物的红外光谱并由此求得了它们的热力学性质．     

On the permutability of Bäcklund transformations: 1 infinitesimal Bäcklund transformations of the sine-Gordon equation

Letu′=B _a u be the Bäcklund transformation of the sine-Gordon equation, we prove that $$B_{a + \varepsilon } B_a^{ - 1} u = u + \varepsilon \sum\limits_{n = 0}^\infty {2D^{ - 1} } \frac{{\delta G_{n + 1} }}{{\delta u}}a^{2n} ,$$ where {G _n} is an infinite set of conserved densities of the sine-Gordon equation and η ⁿ ≡D ^?1δG _n /δu are just the symmetries obtained by Olver [17]. Basing upon this expansion, we prove the equivalence between the permutability of the infinitesimal Bäcklund transformations and the involution of the conserved densities of the sine-Gordon equation.     

Derivatives of 2H-pyrazolo[4,5-b]-1,4-thiazine

Derivatives of 2H-pyrazolo[4,5-b]-1,4-thiazine, which tend to undergo dimerization at the 2-methylene group were synthesized by reaction of 5-amino-3-methyl-4-thio-1-phenylpyrazole with -bromoacetophenones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 265–268, February, 1989.