Anomalous hydroalumination of methyl nopol ether with a LiAlH4-3AlBr3 system

Hydroalumination of methyl nopol ether with a LiAlH₄-3AlBr₃ system is accompanied by a skeleton rearrangement and gives 6-dibromoalumo-7-methoxymethyl-2-menthene. Further hydroalumination affords a mixture of 2,6- and 2,5-bis(dibromoalumo)-7-(methoxymethyl)menthanes in 8020 ratio. Hydrolysis and oxidation of these organoaluminum compounds were carried out.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 506–510, March, 1994.     

Essential spectrum and -solutions of one-dimensional Schrödinger operators

In 1949, Hartman and Wintner showed that if the eigenvalue equations of a one-dimensional Schrödinger operator possess square integrable solutions, then the essential spectrum is nowhere dense. Furthermore, they conjectured that this statement could be improved and that under this condition the essential spectrum might always be void. This is shown to be false. It is proved that, on the contrary, every closed, nowhere dense set does occur as the essential spectrum of Schrödinger operators which satisfy the condition of existence of -solutions. The proof of this theorem is based on inverse spectral theory.

     

Cu~(2+)与三磺基四苯基啿卟啉配位反应研究

利用吸收光谱法和直流极谱法研究了Cu~(2+)的还原状态、抗坏态、抗坏血酸浓度及溶解氧对Cu~(2+)与三磺基四苯基卟啉配位反应的影响。结果表明Cu~(2+)与三磺基四苯(?)基四苯基卟啉配位反应的可能机制为抗坏血酸首先将高价铜还原为亚铜,亚铜离子与配位剂生成对氧成对氧敏感的不稳定中间体Cu~(Ⅰ)——三磺基四:苯基卟啉配合物,立即又被溶解氧氧化为Cu(Ⅱ)——Ⅱ)——三磺基四苯基卟啉配合物。     

苯甲酰类化合物构效关系的模式识别研究

用ＣＮＤＯ／２量化方法计算了３５个苯甲酰类化合物的量化指数,并应用模式识别方法研究了该类化合物的结构对治疗患Ｌ１２１０肿瘤小鼠药效的影响,得到满意的分类图。结果表明化合物的抗癌活性的主要影响因素为ＣＱＳ、ＥＬＵＭＯ、ＥＳＨＥＰ和π,药物的抗癌活性主要是通过抑制核苷酸还原酶所致,而且化合物在体内到达受体的过程和难易程度对药效的影响较大。     

SrGa2S4:Ce blue TFEL in new structure

SrGa₂S₄: Ce blue TFEL device with a novel structure was prepared by electron beam evaporation. The dielectric constant of insulator layer in this structure is far less than that in the conventional structure, so the hot-electrons can be accelerated in SiO₂ layers. The stable TFEL with good chromaticity was achieved and the basic characteristics were investigated.     

十八烷基（2—亚硫酸）乙基二甲基铵的合成

由Ｎ,Ｎ－二甲基十八烷基胺和乙撑亚硫酸酯反应合成十八烷基（２－亚硫酸）乙基二甲基铵是一种新型的亚硫酸内酯型两性表面活性剂,经红外光谱和核磁共振谱分析,确定了该化合物的结构,该两性表面活性剂合成方法简单,原料易得,用途广泛,有发展前途。     

大洋多金属结核中五氧化二磷分析方法

试样经ＮａＯＨ溶融,水浸取后,使Ｆｅ、Ｍｎ、Ｃｕ、Ｃｏ、Ｎｉ等共存元素形成氢氧化物沉淀与磷分离,滤液中的磷用磷钼黄光度法测定。方法简便、快速、精密度好、准确度高。经对标准物质ＧＢＷ０７２４９测定,结果与推荐值吻合,ＲＳＤ（ｎ＝１０）〈１．４％。     

平面型无参比电极二氧化硫传感器

制备了一种新型无参比电极由ＮＡＳＩＣＯＮ和ＹＳＺ两种固体电解质及Ｎａ２ＳＯ４辅助电极构成的二氧化硫传感器。实验结果表明,该传感器对二氧化硫产生Ｎｅｒｎｓｔ响应。由于这种传感器采用了平面结构,对比电极和工作电极处于同样气氛中,消除了氧的影响和密封问题,同时有利于传感器的微型化和多元复合。     

Preparation of enantiomerically pure 1,1′-bi-2-naphthols from 85% cinchonine and 1,1′-bi-2-naphtholboric anhydride

A possibility of preparation of enantiomerically pure 1,1′-bi-2-naphthols using an impure cinchonine has been examined. The solid and the mother liquor formed from the reaction of 1,1′-bi-2-naphtholboric anhydride and 85% cinchonine in toluene could give optically pure (S)-(−)- and (R)-(+)-1,1′-bi-2-naphthol after acidification and kinetic crystallization, the overall yields were 40% and 28%, respectively. Supported by the National Natural Science Foundation of China (2937206) and the Natural Science Foundation of Hubei Province (93J27) Xiong Ying, born in 1971, Graduate student     

Search for new antiphytovirucides

The lead compound of substituted 2-(4′-hydroxyphenyl)benzimidazoles were modified by phosphorylation sulfonation and carboxymethylation. The benzimidazoloamidophosphate (6) (7) have better activity against tobacco mosaic virus (TMV). The benzimidazolophenoxyacetic acid, phenoxysulfonic acid containing trifluoromethyl, and nitro group have 77%≈85% efficiency for wheat rust disease. Supported by the National Natural Science Foundation of China and National Laboratory of Elemento Organic Chemistry Nankai University Qu Fanqi: born in 1952, Associate professor