Quantum deconstruction of the infrared spectrum of CH5+

We present two quantum calculations of the infrared spectrum of protonated methane (CH5+) using full-dimensional, ab initio-based potential energy and dipole moment surfaces. The calculated spectra compare well with a low-resolution experimental spectrum except below 1000 cm(-1), where the experimental spectrum shows no absorption. The present calculations find substantial absorption features below 1000 cm(-1), in qualitative agreement with earlier classical calculations of the spectrum. The major spectral bands are analyzed in terms of the molecular motions. Of particular interest is an intense feature at 200 cm(-1), which is due to an isomerization mode that connects two equivalent minima. Very recent high-resolution jet-cooled spectra in the CH stretch region (2825 to 3050 cm(-1)) are also reported, and assignments of the band origins are made, based on the present quantum calculations.     

鲁迅杂文的影响及现实意义

杂文创作,几乎倾注了鲁迅先生的大部分心血。鲁迅先生的杂文对现代传媒中各种评论文体的出现和影响,对杂文创作题材、体裁、手段的开拓,对现代文语言运用的自由无拘、富有创造力的贡献,想象思维的逆向运用和正反的结合可谓影响深远,至今仍有现实意义。     

玉米Ubiquitin启动子的克隆及功能鉴定

根据Cornejo发表的Ubiquitin启动子的序列,设计引物从玉米自交系18红中克隆出该启动子,测序证明与发表的序列具有98%的同源性,并构建了带有该启动子和GUS基因的植物表达载体,将重组质粒导入农杆菌LBA4404,用农杆菌介导法转入烟草和小麦愈伤中,通过GUS染色反应,证明克隆的启动子在单子叶和双子叶植物中均有活性。     

中国缨小蜂科分属检索表

目的进一步发掘中国缨小蜂科寄生蜂资源、补充大棒缨小蜂种类。方法采用马来氏网诱集的方法获取标本,结合文献研究的方法,依据传统形态鉴定和DNA条形码技术对标本进行准确鉴定。结果记述了采自西藏林芝市大棒缨小蜂属(Litus Haliday)一新种——长大棒缨小蜂(Litus longitus Aishan sp. nov.),对种征进行了详细描述,并附形态特征图;提供了中国大棒缨小蜂属已知种的分种检索表;首次报道了长大棒缨小蜂基于COI序列的DNA条形码。结论本研究为中国大棒缨小蜂属分类研究提供参考,并为快速准确鉴定提供分子数据,具有重要的理论价值。     

Adenosine triphosphatase. Sensitive to DDT in synapses of rat brain

The insecticide DDT selectively inhibits the action of a Na(+), K(+), Mg(2+)-adenosine triphosphatase found in the nerve ending fraction of the rat brain. As judged by the concentrations of inhibitors that give 50 percent of enzyme inhibition, DDT was approximately 1000 times more toxic than its non-insecticidal analog, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene. The degrees of inhibition of this enzyme system by various toxic and nontoxic DDT analogs were closely related to a general toxicity in vivo of these compounds. Moreover, the extents of inhibition of this enzyme system by DDT were much higher at low temperatures, an indication of a causal relation between poisoning in vivo by DDT and the inhibition in vitro of the Na(+), K(+), Mg(2+)-adenosine triphosphatase system.