甲氰菊酯与单甲脒复配对桔全爪螨Pnonychus citri的增效作用研究

将甲氰菊酯和单甲脒通过复配对桔全爪螨进行室内毒力测定,表明两种药剂的各种配比均对桔全爪螨存在着不同程度的增效作用,其中以甲氰菊酯与单甲脒按1:4的比例复配增效作用最为明显,共毒系数达到373。田间药效试验也表明,20％的混剂乳油(4％甲氰菊酯 16％单甲脒)的药效明显高于20％的甲氰菊酯乳油和25％的单甲脒乳油。     

The v-v energy transfer of highly vibrationally excited states (I)

The relaxation of the highly vibrationally excited CO (v = 1–8) by CO₂ is studied by timeresolved Fourier transform infrared emission spectroscopy (TR FTIR). 193 nm laser photolysis of the mixture of CHBr₃ with O₂ generates the highly vibrationally excited CO(v) molecules. TR FTIR records the intense infrared emission of CO(v→v-1). The vibrational populations of each level of CO(v) have been determined by the method of spectral simulation. Based on the evolution of the time resolved populations and the differential method, 8 energy transfer rate constants of CO(v = 1–8) to CO₂ molecules areobtained: (5.7±0.1), (5.9±0.1), (5.2±0.2), (3.4±0.2), (2.4±0.3), (2.2±0.4), (2.0±0.4) and (1.8±0.6) (10¹⁴ cm³ · molecule⁻¹ · s⁻¹), respectively. A two-channel energy transfer model can explain the feature of the quenching of CO(v) by CO². For the lower vibrational states of CO, the vibrational energy transfers preferentially to the u³ mode of CO² For the higher levels, the major quenching channel changes to the vibrational energy exchange between CO(v→v-1) and the u¹ mode of CO².     

Structural and expressional analysis of a cDNA that expresses predominantly in rice stamens

The development of stamen is an important stage during the sexual reproduction in higher plants. Studying the genes that predominantly or even specifically expressed in stamens will aid in undestanding the molecular mechanism of stamen development. The structure of a rice CHS-like gene (D5) which predominantly expressed in anthers has been analysised, showing high structural similarity with two other anther-specific genes (A1 and BA42) fromBrassica napus. Northern analysis also reveals that the three genes share a similar expression pattern and that the expression of D5 may relate to the early development of pollens. It is concluded that D5, A1 and BA42 represent a group of diverged CHS-like genes which are related to stamen development.     

The v-v energy transfer of highly vibrationally excited states (II)

The vibrational energy transfer from highly vibrationally excited CO to H₂O molecules is studied by time-resolved Fourier transform infrared emission spectroscopy (TR FTIR). Following the 193 nm laser photolysis of CHBr₃ and O₂ the secondary reactions generate CO(v). The infrared emission of CO(v → v−1) is detected by TR FTIR. The excitation of H₂O molecules is not observed. By the method of the spectral simulation and the differential technique, 8 rate constants for CO(v)/H₂O system are obtained: (1.7 ±0.1), (3.4 ±0.2), (6.2 ±0.4), (8.0 ±1.0), (9.0 ±2.0), (12 ±3), (16 ±4) and (18 ±7) (10¹³cm³ · molecule^-1· s^-1). At least two reasons lead to the efficient energy transfer. One is the contributions of the rotational energy to the vibational energy defect and the other is the result of the complex collision. With the SSH andab initio calculations, the quenching mechanism of CO(v) by H₂O is suggested.     

Cloning, construction of prokaryotic expression vector and expression ofEscherichia coli cytosine deaminase gene

Cytosine deaminase gene ofEscherichia coli strain H-30 was cloned, and its initiation codon of ‘GTG’ was mutated to ‘ATG’ by PCR. Prokaryotic recombinant expression vector pBV220-CD was constructed. Clone with high enzyme activity were selected by detecting their specific activity of cytosine deaminase. 5-FC(5-FC, 5-fluorocytosine) could induce the lethal toxicity to cells containing active CD gene. DNA sequence analysis indicated that there were 16 altered bases and 5 of them resulted in the alteration of amino acids in predicted peptide by comparing DNA sequence of the clone H-30-CD-11 with high enzyme activity with CD gene reported in Gene Bank.     

用^1H—NMR测定纤维素的摩尔取代度

用＾１Ｈ－ＮＭＲ测定羟丙基纤维素的摩尔取代度,根据纤维素在ＤＣｌ中水解后的＾１Ｈ－ＮＭＲ谱峰面积来计算ＭＳ值。同时还应用铬酸氧化蒸馏法测定了羟丙基纤维素的ＭＳ值,以及利用ＭＳ与羟丙基含量的关系得到ＭＳ值,可以发现ＮＭＲ的方法是可行的。     

对称稀疏矩阵三对角化并行算法

本文用Ｇｉｖｅｎｓ变换,给出一个对称稀疏矩阵的三对角化并行算法,具有很好的并行加速及效率,由于充分考虑了矩阵的稀疏性,使算法中数据存储及通讯相当节省。     

极性晶体膜中极化子的性质

使用格林函数法研究在极性晶体膜中极化子自能的一些性质．对ＧａＡｓ进行了计算,结果表明：在绝对零度时,极性晶体膜中电子与体纵光学声子相互作用能的绝对值随极性晶体膜的厚度的增加而增加,随后几乎保持不变．     

海浪统计资料对船舶波浪弯矩设计值的影响

对船舶特别是超规范船舶进行结构的直接计算设计时,设计人员应合理选择船舶航行海域的海浪长期统计资料,根据船舶的装载工况及实际可能达到的航速,借用线性理论或非线性理论进行波浪弯矩的长期预报来确定设计值．文中就一艘大型集装箱船舶,按五个典型海域的海浪统计资料,对波浪弯矩及波浪合成弯矩作了长期预报计算,并与ＩＡＣＳ的统一纵强度要求ＵＲ－Ｓ１１的结果作比较和分析,给出了对船舶结构直接计算设计有指导意义的几点结论．