Structure of Vortex Dislocations in a Wake-type Flow

Structure and dynamical processes of vortex dislocations in a kind of wake-type flow are described clearly by vortex lines, which are directly constructed from data of three-dimensional direct numerical simulations of the flow evolution.

强红外激光引起BCl_3分子可见荧光的脉冲光-声-光效应

用时间、空间分辨的方法研究了OAO荧光对时间、空间的依赖关系。观察到反应池几何形状对OAO荧光的显著影响。记录了CO_2脉冲激光激发BCl_3分子时形成的脉冲声波,及其与OAO荧光的对应关系。证实了OAO荧光是脉冲声波对BCl_3激发态分子的再激发。用简单的模型计算了OAO荧光的形成、轴向移动速度,结果与实验基本一致。

合成孔径激光成像雷达(Ⅱ):空间相位偏置发射望远镜

报道一种可以进行空间相位偏置的光学望远镜,用作合成孔径激光成像雷达中的光学发射天线。在望远镜内放置相位调制平板,控制望远镜的离焦量和位相调制平板的相位函数,能够在激光望远镜的照明区产生可控制的附加空间相位二次项,灵活改变激光照明波前,以在目标回波接收信号中产生雷达运动方向上的所需的二次项相位历程,因此能够实现特定的方位向成像分辨率。

Sphenadilactones A and B, two novel nortriterpenoids from Schisandra sphenanthera

Two novel nortriterpenoid compounds, sphenadilactones A (1) and B (2), have been isolated from the leaves and stems of Schisandra sphenanthera. The structural elucidation of 1 and 2 was accomplished by extensive NMR analysis. The relative stereochemistry

苏拉维西猴（Macaca nigra）的肝细胞癌

本文报道了一只实验室出生的，成年维性苏拉维西猴的肝细胞癌的病理解剖学和病理组织学变化，同时还讨论了自发性糖尿病和D型逆转录病毒与肝细胞癌的关系。

保定市工业废水对白洋淀微型生物群落的生态毒性

以白洋淀PFU(PolyurethaneFoamUnit)微型生物群落为种源(epicenter),评价上游工业废水的生态毒性.结果表明,在反映原生动物群集过程的3个参数Seq、G和T90%中,Seq与工业废水体积分数(φ)呈负相关.根据其回归方程Seq=42.22857-0.33374φ(R2=0.9042,P<0.01)推算出工业废水的效应浓度EC5、EC20和EC50,分别为6.3%、25.3%和65.2%.以此确定上游工业废水对白洋淀微型生物群落的无效应浓度为6.3%,最大允许浓度(MATC)为2

Realization of low threshold of InGaAs/InAlAs quantum cascade laser

By optimizing the molecule beam epitaxy growth condition, the quality of quantum cascade (QC) material has greatly been improved. The spectrum of double x-ray diffraction indicates that the interface between the constituent layers is very smooth, the lattice mismatch between the epilayer and the substrate is less than 0.1%, and the periodicity fluctuation of the active region is not more than 4.2%. The QC laser with the emission wavelength of about 5.1 mum is operated at the threshold of 0.73 kA/cm(2) at liquid nitrogen temperature with the repetition rate of 10kHz and at a duty cycle of 1%. Meanwhile, the performance of the laser can be improved with suitable post process techniques such as the metallic ohmic contact technology.

正构烷烃及单体碳同位素的古植被与古气候意义

IEECAS SKLLQG

植物硒素营养及其机理研究进展

土壤生境中Se的丰缺对植物的Se素营养有重要的影响 .本文阐述了植物对Se的吸收、积累和运移过程 ,概述了Se对植物的毒性、对植物产量和品质影响及其机理研究的进展 .在此基础上 ,提出以研究Se对土壤酶活性影响来解释Se对植物的必要性的新途径 .