中国科学院力学研究所2001年度科研状况与主要进展

<正>2001年是跨入新世纪的第一年,也是“十五”的第一年．在此年度,力学所的科研工作在诸多层面上都取得了重要的突破和进展．

Zn~(2+)浓度对固氮鱼腥藻(Anabaena azotica Ley)光能转化特性的影响

本实验对在不同Zn2+浓度条件下培养的固氮鱼腥藻(Anabaena azoticaLey)的生长、光合放氧速率和叶绿素荧光参数Fv/Fm进行了测定.结果表明,当Zn2+浓度为1.0μmol/L时,其比生长速率(Specific growth rate)最大,光合放氧速率和Fv/Fm值最高.当Zn2+浓度大于等于5.0μmol/L时会抑制A.azotica Ley的生长和光合作用.对在0μmol/L和5.0μmol/L Zn2+浓度下生长的藻细胞藻胆体-类囊体膜复合物吸收光谱的比较和对与5.0μmol/L

Description of a new species of the genus Tylopharynx (Nemata : Diplogasteroidea), T-clariamphida sp n., with a redescription of T-foetida (Butschli, 1874) Goffart, 1930

Tylopharynx clariamphida sp. n. is described from muddy sand collected in Anhui Province, China. It can be distinguished from T foetida (Butschli, 1874), the type and only species of the genus, by numerous characters: having 24 to 26 prominent and clearly separated longitudinal ridges, a higher lip region with no hint of a cephalic framework, more prominent amphidial foveae in lateral view, wider and more posteriorly located amphidial apertures, smaller basal knobs of stoma, longer metacorpus, more enlarged phasmids, shorter spicules with shorter digitate terminus, shorter reflexed part of testis, and thicker gubernaculum with more angular shape. For comparison, an expanded description is given for T foetida from Belgium, and SEM photographs of both species are provided.

Defect states in cubic GaN epilayer grown on GaAs by metalorganic vapor phase epitaxy

Defect states in cubic GaN epilayers grown on GaAs were investigated with the photoluminescence technique. One shallow donor and two acceptors were identified to be involved in relevant optical transitions. The binding energies of the free excitons, the bound excitons. the donor and the acceptors were determined. These values are in good agreement with recent theoretical results.

国家自然科学基金半导体学科2001年项目概况分析

简介并分析最近几年半导体学科基金项目申请和资助的发展趋势以及2001年半导体学科基金申请与资助概况，并附2001年半导体学科批准资助的面上及重点项目，供有关科技工作者参考。

Defect states in cubic GaN epilayer grown on GaAs by metalorganic vapor phase epitaxy

Defect states in cubic GaN epilayers grown on GaAs were investigated with the photoluminescence technique. One shallow donor and two acceptors were identified to be involved in relevant optical transitions. The binding energies of the free excitons, the bound excitons. the donor and the acceptors were determined. These values are in good agreement with recent theoretical results.

Tree-ringbased drought reconstruction (a.d. 1855-2001) for the Qilian mountains；northwestern China

IEECAS SKLLQG