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     

关于时滞Liénard型方程的周期解

本文研究具有时滞的Lienard型方程周期解的存在性,得到了一些新的结果。     

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     

关于Hamilton图的一点注记

通过类似于对一可平面图求生成树个数的方法,得到一个关于Hamilton图的Hamilton圈的个数的等式。并讨论了一类特殊的平面图。     

Molecular cloning and nucleotide sequence of classical swine fever virus strain Shimen

According to the previously published CSFV sequences, 18 paris of partially overlapping primers which span the entire genome of CSFV strain Shimen were designed and synthesized. Each cDNA fragment of strain Shimen was amplified by RT-PCR method from the anticoagulant blood of strain Shimen infected pig. The PCR fragments were cloned into pGEM-T vector respectively and sequenced. The results show that we have obtained the nucleotide sequence of strain Shimen. The viral RNA consists of 12 297 nucleotides including noncoding regions of 373 and 227 bases at the 5′ and 3′ end, respectively, and a single large open reading frame spanning 11 697 nucleotides in the middle, which encodes an amino acid sequence of 3 989 residues with a calculated molecular weight of 437.6×10³. The precisely sequencing of 5′ and 3′ termini is undertaking. Supported by the National Pandeng Project Huang Qianhua: born in 1968. Graduate student     

并联机器人及其机构学理论

介绍了并联式机器人,以及并联机器人机构学理论及其发展,特别介绍在称为２１世纪的新型机床;分析了并联机器人的结构,特点和广泛的应用前景。     

仔猪混合感染致病性白色葡萄球菌和大肠杆菌的诊断及防制初报

经过病原的分离鉴定、致病性试验及病仔猪防治效果的分析,确诊某集约化养猪场仔猪发生以“渗出性皮炎”为主的疾病为致病性白色葡萄球菌和大肠杆菌混合感染,通过采取综合的防制措施后,彻底控制本病的发生和流行。     

热电偶测温结果的校准

本文介绍了用高精度的水银温度计测得的温度作为标准温度,来校准热电偶的测温结果,并用最小二乘法来拟合其修正公式的方法。     

屋盖承重结构起拱的力学分析及起拱方式探讨

对不同材料的屋盖承重结构在起拱的受力和方式方面进行了分析笔探讨并提出了建设性的意见。